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diff --git a/gcc-4.9/gcc/ada/sem_ch12.adb b/gcc-4.9/gcc/ada/sem_ch12.adb new file mode 100644 index 000000000..5aa090446 --- /dev/null +++ b/gcc-4.9/gcc/ada/sem_ch12.adb @@ -0,0 +1,14023 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S E M _ C H 1 2 -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 1992-2013, Free Software Foundation, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 3, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- +-- for more details. You should have received a copy of the GNU General -- +-- Public License distributed with GNAT; see file COPYING3. If not, go to -- +-- http://www.gnu.org/licenses for a complete copy of the license. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- -- +------------------------------------------------------------------------------ + +with Aspects; use Aspects; +with Atree; use Atree; +with Debug; use Debug; +with Einfo; use Einfo; +with Elists; use Elists; +with Errout; use Errout; +with Expander; use Expander; +with Exp_Disp; use Exp_Disp; +with Fname; use Fname; +with Fname.UF; use Fname.UF; +with Freeze; use Freeze; +with Itypes; use Itypes; +with Lib; use Lib; +with Lib.Load; use Lib.Load; +with Lib.Xref; use Lib.Xref; +with Nlists; use Nlists; +with Namet; use Namet; +with Nmake; use Nmake; +with Opt; use Opt; +with Rident; use Rident; +with Restrict; use Restrict; +with Rtsfind; use Rtsfind; +with Sem; use Sem; +with Sem_Aux; use Sem_Aux; +with Sem_Cat; use Sem_Cat; +with Sem_Ch3; use Sem_Ch3; +with Sem_Ch6; use Sem_Ch6; +with Sem_Ch7; use Sem_Ch7; +with Sem_Ch8; use Sem_Ch8; +with Sem_Ch10; use Sem_Ch10; +with Sem_Ch13; use Sem_Ch13; +with Sem_Dim; use Sem_Dim; +with Sem_Disp; use Sem_Disp; +with Sem_Elab; use Sem_Elab; +with Sem_Elim; use Sem_Elim; +with Sem_Eval; use Sem_Eval; +with Sem_Prag; use Sem_Prag; +with Sem_Res; use Sem_Res; +with Sem_Type; use Sem_Type; +with Sem_Util; use Sem_Util; +with Sem_Warn; use Sem_Warn; +with Stand; use Stand; +with Sinfo; use Sinfo; +with Sinfo.CN; use Sinfo.CN; +with Sinput; use Sinput; +with Sinput.L; use Sinput.L; +with Snames; use Snames; +with Stringt; use Stringt; +with Uname; use Uname; +with Table; +with Tbuild; use Tbuild; +with Uintp; use Uintp; +with Urealp; use Urealp; +with Warnsw; use Warnsw; + +with GNAT.HTable; + +package body Sem_Ch12 is + + ---------------------------------------------------------- + -- Implementation of Generic Analysis and Instantiation -- + ---------------------------------------------------------- + + -- GNAT implements generics by macro expansion. No attempt is made to share + -- generic instantiations (for now). Analysis of a generic definition does + -- not perform any expansion action, but the expander must be called on the + -- tree for each instantiation, because the expansion may of course depend + -- on the generic actuals. All of this is best achieved as follows: + -- + -- a) Semantic analysis of a generic unit is performed on a copy of the + -- tree for the generic unit. All tree modifications that follow analysis + -- do not affect the original tree. Links are kept between the original + -- tree and the copy, in order to recognize non-local references within + -- the generic, and propagate them to each instance (recall that name + -- resolution is done on the generic declaration: generics are not really + -- macros). This is summarized in the following diagram: + + -- .-----------. .----------. + -- | semantic |<--------------| generic | + -- | copy | | unit | + -- | |==============>| | + -- |___________| global |__________| + -- references | | | + -- | | | + -- .-----|--|. + -- | .-----|---. + -- | | .----------. + -- | | | generic | + -- |__| | | + -- |__| instance | + -- |__________| + + -- b) Each instantiation copies the original tree, and inserts into it a + -- series of declarations that describe the mapping between generic formals + -- and actuals. For example, a generic In OUT parameter is an object + -- renaming of the corresponding actual, etc. Generic IN parameters are + -- constant declarations. + + -- c) In order to give the right visibility for these renamings, we use + -- a different scheme for package and subprogram instantiations. For + -- packages, the list of renamings is inserted into the package + -- specification, before the visible declarations of the package. The + -- renamings are analyzed before any of the text of the instance, and are + -- thus visible at the right place. Furthermore, outside of the instance, + -- the generic parameters are visible and denote their corresponding + -- actuals. + + -- For subprograms, we create a container package to hold the renamings + -- and the subprogram instance itself. Analysis of the package makes the + -- renaming declarations visible to the subprogram. After analyzing the + -- package, the defining entity for the subprogram is touched-up so that + -- it appears declared in the current scope, and not inside the container + -- package. + + -- If the instantiation is a compilation unit, the container package is + -- given the same name as the subprogram instance. This ensures that + -- the elaboration procedure called by the binder, using the compilation + -- unit name, calls in fact the elaboration procedure for the package. + + -- Not surprisingly, private types complicate this approach. By saving in + -- the original generic object the non-local references, we guarantee that + -- the proper entities are referenced at the point of instantiation. + -- However, for private types, this by itself does not insure that the + -- proper VIEW of the entity is used (the full type may be visible at the + -- point of generic definition, but not at instantiation, or vice-versa). + -- In order to reference the proper view, we special-case any reference + -- to private types in the generic object, by saving both views, one in + -- the generic and one in the semantic copy. At time of instantiation, we + -- check whether the two views are consistent, and exchange declarations if + -- necessary, in order to restore the correct visibility. Similarly, if + -- the instance view is private when the generic view was not, we perform + -- the exchange. After completing the instantiation, we restore the + -- current visibility. The flag Has_Private_View marks identifiers in the + -- the generic unit that require checking. + + -- Visibility within nested generic units requires special handling. + -- Consider the following scheme: + + -- type Global is ... -- outside of generic unit. + -- generic ... + -- package Outer is + -- ... + -- type Semi_Global is ... -- global to inner. + + -- generic ... -- 1 + -- procedure inner (X1 : Global; X2 : Semi_Global); + + -- procedure in2 is new inner (...); -- 4 + -- end Outer; + + -- package New_Outer is new Outer (...); -- 2 + -- procedure New_Inner is new New_Outer.Inner (...); -- 3 + + -- The semantic analysis of Outer captures all occurrences of Global. + -- The semantic analysis of Inner (at 1) captures both occurrences of + -- Global and Semi_Global. + + -- At point 2 (instantiation of Outer), we also produce a generic copy + -- of Inner, even though Inner is, at that point, not being instantiated. + -- (This is just part of the semantic analysis of New_Outer). + + -- Critically, references to Global within Inner must be preserved, while + -- references to Semi_Global should not preserved, because they must now + -- resolve to an entity within New_Outer. To distinguish between these, we + -- use a global variable, Current_Instantiated_Parent, which is set when + -- performing a generic copy during instantiation (at 2). This variable is + -- used when performing a generic copy that is not an instantiation, but + -- that is nested within one, as the occurrence of 1 within 2. The analysis + -- of a nested generic only preserves references that are global to the + -- enclosing Current_Instantiated_Parent. We use the Scope_Depth value to + -- determine whether a reference is external to the given parent. + + -- The instantiation at point 3 requires no special treatment. The method + -- works as well for further nestings of generic units, but of course the + -- variable Current_Instantiated_Parent must be stacked because nested + -- instantiations can occur, e.g. the occurrence of 4 within 2. + + -- The instantiation of package and subprogram bodies is handled in a + -- similar manner, except that it is delayed until after semantic + -- analysis is complete. In this fashion complex cross-dependencies + -- between several package declarations and bodies containing generics + -- can be compiled which otherwise would diagnose spurious circularities. + + -- For example, it is possible to compile two packages A and B that + -- have the following structure: + + -- package A is package B is + -- generic ... generic ... + -- package G_A is package G_B is + + -- with B; with A; + -- package body A is package body B is + -- package N_B is new G_B (..) package N_A is new G_A (..) + + -- The table Pending_Instantiations in package Inline is used to keep + -- track of body instantiations that are delayed in this manner. Inline + -- handles the actual calls to do the body instantiations. This activity + -- is part of Inline, since the processing occurs at the same point, and + -- for essentially the same reason, as the handling of inlined routines. + + ---------------------------------------------- + -- Detection of Instantiation Circularities -- + ---------------------------------------------- + + -- If we have a chain of instantiations that is circular, this is static + -- error which must be detected at compile time. The detection of these + -- circularities is carried out at the point that we insert a generic + -- instance spec or body. If there is a circularity, then the analysis of + -- the offending spec or body will eventually result in trying to load the + -- same unit again, and we detect this problem as we analyze the package + -- instantiation for the second time. + + -- At least in some cases after we have detected the circularity, we get + -- into trouble if we try to keep going. The following flag is set if a + -- circularity is detected, and used to abandon compilation after the + -- messages have been posted. + + Circularity_Detected : Boolean := False; + -- This should really be reset on encountering a new main unit, but in + -- practice we are not using multiple main units so it is not critical. + + -------------------------------------------------- + -- Formal packages and partial parameterization -- + -------------------------------------------------- + + -- When compiling a generic, a formal package is a local instantiation. If + -- declared with a box, its generic formals are visible in the enclosing + -- generic. If declared with a partial list of actuals, those actuals that + -- are defaulted (covered by an Others clause, or given an explicit box + -- initialization) are also visible in the enclosing generic, while those + -- that have a corresponding actual are not. + + -- In our source model of instantiation, the same visibility must be + -- present in the spec and body of an instance: the names of the formals + -- that are defaulted must be made visible within the instance, and made + -- invisible (hidden) after the instantiation is complete, so that they + -- are not accessible outside of the instance. + + -- In a generic, a formal package is treated like a special instantiation. + -- Our Ada 95 compiler handled formals with and without box in different + -- ways. With partial parameterization, we use a single model for both. + -- We create a package declaration that consists of the specification of + -- the generic package, and a set of declarations that map the actuals + -- into local renamings, just as we do for bona fide instantiations. For + -- defaulted parameters and formals with a box, we copy directly the + -- declarations of the formal into this local package. The result is a + -- a package whose visible declarations may include generic formals. This + -- package is only used for type checking and visibility analysis, and + -- never reaches the back-end, so it can freely violate the placement + -- rules for generic formal declarations. + + -- The list of declarations (renamings and copies of formals) is built + -- by Analyze_Associations, just as for regular instantiations. + + -- At the point of instantiation, conformance checking must be applied only + -- to those parameters that were specified in the formal. We perform this + -- checking by creating another internal instantiation, this one including + -- only the renamings and the formals (the rest of the package spec is not + -- relevant to conformance checking). We can then traverse two lists: the + -- list of actuals in the instance that corresponds to the formal package, + -- and the list of actuals produced for this bogus instantiation. We apply + -- the conformance rules to those actuals that are not defaulted (i.e. + -- which still appear as generic formals. + + -- When we compile an instance body we must make the right parameters + -- visible again. The predicate Is_Generic_Formal indicates which of the + -- formals should have its Is_Hidden flag reset. + + ----------------------- + -- Local subprograms -- + ----------------------- + + procedure Abandon_Instantiation (N : Node_Id); + pragma No_Return (Abandon_Instantiation); + -- Posts an error message "instantiation abandoned" at the indicated node + -- and then raises the exception Instantiation_Error to do it. + + procedure Analyze_Formal_Array_Type + (T : in out Entity_Id; + Def : Node_Id); + -- A formal array type is treated like an array type declaration, and + -- invokes Array_Type_Declaration (sem_ch3) whose first parameter is + -- in-out, because in the case of an anonymous type the entity is + -- actually created in the procedure. + + -- The following procedures treat other kinds of formal parameters + + procedure Analyze_Formal_Derived_Interface_Type + (N : Node_Id; + T : Entity_Id; + Def : Node_Id); + + procedure Analyze_Formal_Derived_Type + (N : Node_Id; + T : Entity_Id; + Def : Node_Id); + + procedure Analyze_Formal_Interface_Type + (N : Node_Id; + T : Entity_Id; + Def : Node_Id); + + -- The following subprograms create abbreviated declarations for formal + -- scalar types. We introduce an anonymous base of the proper class for + -- each of them, and define the formals as constrained first subtypes of + -- their bases. The bounds are expressions that are non-static in the + -- generic. + + procedure Analyze_Formal_Decimal_Fixed_Point_Type + (T : Entity_Id; Def : Node_Id); + procedure Analyze_Formal_Discrete_Type (T : Entity_Id; Def : Node_Id); + procedure Analyze_Formal_Floating_Type (T : Entity_Id; Def : Node_Id); + procedure Analyze_Formal_Signed_Integer_Type (T : Entity_Id; Def : Node_Id); + procedure Analyze_Formal_Modular_Type (T : Entity_Id; Def : Node_Id); + procedure Analyze_Formal_Ordinary_Fixed_Point_Type + (T : Entity_Id; Def : Node_Id); + + procedure Analyze_Formal_Private_Type + (N : Node_Id; + T : Entity_Id; + Def : Node_Id); + -- Creates a new private type, which does not require completion + + procedure Analyze_Formal_Incomplete_Type (T : Entity_Id; Def : Node_Id); + -- Ada 2012: Creates a new incomplete type whose actual does not freeze + + procedure Analyze_Generic_Formal_Part (N : Node_Id); + -- Analyze generic formal part + + procedure Analyze_Generic_Access_Type (T : Entity_Id; Def : Node_Id); + -- Create a new access type with the given designated type + + function Analyze_Associations + (I_Node : Node_Id; + Formals : List_Id; + F_Copy : List_Id) return List_Id; + -- At instantiation time, build the list of associations between formals + -- and actuals. Each association becomes a renaming declaration for the + -- formal entity. F_Copy is the analyzed list of formals in the generic + -- copy. It is used to apply legality checks to the actuals. I_Node is the + -- instantiation node itself. + + procedure Analyze_Subprogram_Instantiation + (N : Node_Id; + K : Entity_Kind); + + procedure Build_Instance_Compilation_Unit_Nodes + (N : Node_Id; + Act_Body : Node_Id; + Act_Decl : Node_Id); + -- This procedure is used in the case where the generic instance of a + -- subprogram body or package body is a library unit. In this case, the + -- original library unit node for the generic instantiation must be + -- replaced by the resulting generic body, and a link made to a new + -- compilation unit node for the generic declaration. The argument N is + -- the original generic instantiation. Act_Body and Act_Decl are the body + -- and declaration of the instance (either package body and declaration + -- nodes or subprogram body and declaration nodes depending on the case). + -- On return, the node N has been rewritten with the actual body. + + procedure Check_Access_Definition (N : Node_Id); + -- Subsidiary routine to null exclusion processing. Perform an assertion + -- check on Ada version and the presence of an access definition in N. + + procedure Check_Formal_Packages (P_Id : Entity_Id); + -- Apply the following to all formal packages in generic associations + + procedure Check_Formal_Package_Instance + (Formal_Pack : Entity_Id; + Actual_Pack : Entity_Id); + -- Verify that the actuals of the actual instance match the actuals of + -- the template for a formal package that is not declared with a box. + + procedure Check_Forward_Instantiation (Decl : Node_Id); + -- If the generic is a local entity and the corresponding body has not + -- been seen yet, flag enclosing packages to indicate that it will be + -- elaborated after the generic body. Subprograms declared in the same + -- package cannot be inlined by the front-end because front-end inlining + -- requires a strict linear order of elaboration. + + function Check_Hidden_Primitives (Assoc_List : List_Id) return Elist_Id; + -- Check if some association between formals and actuals requires to make + -- visible primitives of a tagged type, and make those primitives visible. + -- Return the list of primitives whose visibility is modified (to restore + -- their visibility later through Restore_Hidden_Primitives). If no + -- candidate is found then return No_Elist. + + procedure Check_Hidden_Child_Unit + (N : Node_Id; + Gen_Unit : Entity_Id; + Act_Decl_Id : Entity_Id); + -- If the generic unit is an implicit child instance within a parent + -- instance, we need to make an explicit test that it is not hidden by + -- a child instance of the same name and parent. + + procedure Check_Generic_Actuals + (Instance : Entity_Id; + Is_Formal_Box : Boolean); + -- Similar to previous one. Check the actuals in the instantiation, + -- whose views can change between the point of instantiation and the point + -- of instantiation of the body. In addition, mark the generic renamings + -- as generic actuals, so that they are not compatible with other actuals. + -- Recurse on an actual that is a formal package whose declaration has + -- a box. + + function Contains_Instance_Of + (Inner : Entity_Id; + Outer : Entity_Id; + N : Node_Id) return Boolean; + -- Inner is instantiated within the generic Outer. Check whether Inner + -- directly or indirectly contains an instance of Outer or of one of its + -- parents, in the case of a subunit. Each generic unit holds a list of + -- the entities instantiated within (at any depth). This procedure + -- determines whether the set of such lists contains a cycle, i.e. an + -- illegal circular instantiation. + + function Denotes_Formal_Package + (Pack : Entity_Id; + On_Exit : Boolean := False; + Instance : Entity_Id := Empty) return Boolean; + -- Returns True if E is a formal package of an enclosing generic, or + -- the actual for such a formal in an enclosing instantiation. If such + -- a package is used as a formal in an nested generic, or as an actual + -- in a nested instantiation, the visibility of ITS formals should not + -- be modified. When called from within Restore_Private_Views, the flag + -- On_Exit is true, to indicate that the search for a possible enclosing + -- instance should ignore the current one. In that case Instance denotes + -- the declaration for which this is an actual. This declaration may be + -- an instantiation in the source, or the internal instantiation that + -- corresponds to the actual for a formal package. + + function Earlier (N1, N2 : Node_Id) return Boolean; + -- Yields True if N1 and N2 appear in the same compilation unit, + -- ignoring subunits, and if N1 is to the left of N2 in a left-to-right + -- traversal of the tree for the unit. Used to determine the placement + -- of freeze nodes for instance bodies that may depend on other instances. + + function Find_Actual_Type + (Typ : Entity_Id; + Gen_Type : Entity_Id) return Entity_Id; + -- When validating the actual types of a child instance, check whether + -- the formal is a formal type of the parent unit, and retrieve the current + -- actual for it. Typ is the entity in the analyzed formal type declaration + -- (component or index type of an array type, or designated type of an + -- access formal) and Gen_Type is the enclosing analyzed formal array + -- or access type. The desired actual may be a formal of a parent, or may + -- be declared in a formal package of a parent. In both cases it is a + -- generic actual type because it appears within a visible instance. + -- Finally, it may be declared in a parent unit without being a formal + -- of that unit, in which case it must be retrieved by visibility. + -- Ambiguities may still arise if two homonyms are declared in two formal + -- packages, and the prefix of the formal type may be needed to resolve + -- the ambiguity in the instance ??? + + function In_Same_Declarative_Part + (F_Node : Node_Id; + Inst : Node_Id) return Boolean; + -- True if the instantiation Inst and the given freeze_node F_Node appear + -- within the same declarative part, ignoring subunits, but with no inter- + -- vening subprograms or concurrent units. Used to find the proper plave + -- for the freeze node of an instance, when the generic is declared in a + -- previous instance. If predicate is true, the freeze node of the instance + -- can be placed after the freeze node of the previous instance, Otherwise + -- it has to be placed at the end of the current declarative part. + + function In_Main_Context (E : Entity_Id) return Boolean; + -- Check whether an instantiation is in the context of the main unit. + -- Used to determine whether its body should be elaborated to allow + -- front-end inlining. + + procedure Set_Instance_Env + (Gen_Unit : Entity_Id; + Act_Unit : Entity_Id); + -- Save current instance on saved environment, to be used to determine + -- the global status of entities in nested instances. Part of Save_Env. + -- called after verifying that the generic unit is legal for the instance, + -- The procedure also examines whether the generic unit is a predefined + -- unit, in order to set configuration switches accordingly. As a result + -- the procedure must be called after analyzing and freezing the actuals. + + procedure Set_Instance_Of (A : Entity_Id; B : Entity_Id); + -- Associate analyzed generic parameter with corresponding + -- instance. Used for semantic checks at instantiation time. + + function Has_Been_Exchanged (E : Entity_Id) return Boolean; + -- Traverse the Exchanged_Views list to see if a type was private + -- and has already been flipped during this phase of instantiation. + + procedure Hide_Current_Scope; + -- When instantiating a generic child unit, the parent context must be + -- present, but the instance and all entities that may be generated + -- must be inserted in the current scope. We leave the current scope + -- on the stack, but make its entities invisible to avoid visibility + -- problems. This is reversed at the end of the instantiation. This is + -- not done for the instantiation of the bodies, which only require the + -- instances of the generic parents to be in scope. + + procedure Install_Body + (Act_Body : Node_Id; + N : Node_Id; + Gen_Body : Node_Id; + Gen_Decl : Node_Id); + -- If the instantiation happens textually before the body of the generic, + -- the instantiation of the body must be analyzed after the generic body, + -- and not at the point of instantiation. Such early instantiations can + -- happen if the generic and the instance appear in a package declaration + -- because the generic body can only appear in the corresponding package + -- body. Early instantiations can also appear if generic, instance and + -- body are all in the declarative part of a subprogram or entry. Entities + -- of packages that are early instantiations are delayed, and their freeze + -- node appears after the generic body. + + procedure Insert_Freeze_Node_For_Instance + (N : Node_Id; + F_Node : Node_Id); + -- N denotes a package or a subprogram instantiation and F_Node is the + -- associated freeze node. Insert the freeze node before the first source + -- body which follows immediately after N. If no such body is found, the + -- freeze node is inserted at the end of the declarative region which + -- contains N. + + procedure Freeze_Subprogram_Body + (Inst_Node : Node_Id; + Gen_Body : Node_Id; + Pack_Id : Entity_Id); + -- The generic body may appear textually after the instance, including + -- in the proper body of a stub, or within a different package instance. + -- Given that the instance can only be elaborated after the generic, we + -- place freeze_nodes for the instance and/or for packages that may enclose + -- the instance and the generic, so that the back-end can establish the + -- proper order of elaboration. + + procedure Init_Env; + -- Establish environment for subsequent instantiation. Separated from + -- Save_Env because data-structures for visibility handling must be + -- initialized before call to Check_Generic_Child_Unit. + + procedure Install_Formal_Packages (Par : Entity_Id); + -- Install the visible part of any formal of the parent that is a formal + -- package. Note that for the case of a formal package with a box, this + -- includes the formal part of the formal package (12.7(10/2)). + + procedure Install_Parent (P : Entity_Id; In_Body : Boolean := False); + -- When compiling an instance of a child unit the parent (which is + -- itself an instance) is an enclosing scope that must be made + -- immediately visible. This procedure is also used to install the non- + -- generic parent of a generic child unit when compiling its body, so + -- that full views of types in the parent are made visible. + + procedure Remove_Parent (In_Body : Boolean := False); + -- Reverse effect after instantiation of child is complete + + procedure Install_Hidden_Primitives + (Prims_List : in out Elist_Id; + Gen_T : Entity_Id; + Act_T : Entity_Id); + -- Remove suffix 'P' from hidden primitives of Act_T to match the + -- visibility of primitives of Gen_T. The list of primitives to which + -- the suffix is removed is added to Prims_List to restore them later. + + procedure Restore_Hidden_Primitives (Prims_List : in out Elist_Id); + -- Restore suffix 'P' to primitives of Prims_List and leave Prims_List + -- set to No_Elist. + + procedure Inline_Instance_Body + (N : Node_Id; + Gen_Unit : Entity_Id; + Act_Decl : Node_Id); + -- If front-end inlining is requested, instantiate the package body, + -- and preserve the visibility of its compilation unit, to insure + -- that successive instantiations succeed. + + -- The functions Instantiate_XXX perform various legality checks and build + -- the declarations for instantiated generic parameters. In all of these + -- Formal is the entity in the generic unit, Actual is the entity of + -- expression in the generic associations, and Analyzed_Formal is the + -- formal in the generic copy, which contains the semantic information to + -- be used to validate the actual. + + function Instantiate_Object + (Formal : Node_Id; + Actual : Node_Id; + Analyzed_Formal : Node_Id) return List_Id; + + function Instantiate_Type + (Formal : Node_Id; + Actual : Node_Id; + Analyzed_Formal : Node_Id; + Actual_Decls : List_Id) return List_Id; + + function Instantiate_Formal_Subprogram + (Formal : Node_Id; + Actual : Node_Id; + Analyzed_Formal : Node_Id) return Node_Id; + + function Instantiate_Formal_Package + (Formal : Node_Id; + Actual : Node_Id; + Analyzed_Formal : Node_Id) return List_Id; + -- If the formal package is declared with a box, special visibility rules + -- apply to its formals: they are in the visible part of the package. This + -- is true in the declarative region of the formal package, that is to say + -- in the enclosing generic or instantiation. For an instantiation, the + -- parameters of the formal package are made visible in an explicit step. + -- Furthermore, if the actual has a visible USE clause, these formals must + -- be made potentially use-visible as well. On exit from the enclosing + -- instantiation, the reverse must be done. + + -- For a formal package declared without a box, there are conformance rules + -- that apply to the actuals in the generic declaration and the actuals of + -- the actual package in the enclosing instantiation. The simplest way to + -- apply these rules is to repeat the instantiation of the formal package + -- in the context of the enclosing instance, and compare the generic + -- associations of this instantiation with those of the actual package. + -- This internal instantiation only needs to contain the renamings of the + -- formals: the visible and private declarations themselves need not be + -- created. + + -- In Ada 2005, the formal package may be only partially parameterized. + -- In that case the visibility step must make visible those actuals whose + -- corresponding formals were given with a box. A final complication + -- involves inherited operations from formal derived types, which must + -- be visible if the type is. + + function Is_In_Main_Unit (N : Node_Id) return Boolean; + -- Test if given node is in the main unit + + procedure Load_Parent_Of_Generic + (N : Node_Id; + Spec : Node_Id; + Body_Optional : Boolean := False); + -- If the generic appears in a separate non-generic library unit, load the + -- corresponding body to retrieve the body of the generic. N is the node + -- for the generic instantiation, Spec is the generic package declaration. + -- + -- Body_Optional is a flag that indicates that the body is being loaded to + -- ensure that temporaries are generated consistently when there are other + -- instances in the current declarative part that precede the one being + -- loaded. In that case a missing body is acceptable. + + procedure Inherit_Context (Gen_Decl : Node_Id; Inst : Node_Id); + -- Add the context clause of the unit containing a generic unit to a + -- compilation unit that is, or contains, an instantiation. + + function Get_Associated_Node (N : Node_Id) return Node_Id; + -- In order to propagate semantic information back from the analyzed copy + -- to the original generic, we maintain links between selected nodes in the + -- generic and their corresponding copies. At the end of generic analysis, + -- the routine Save_Global_References traverses the generic tree, examines + -- the semantic information, and preserves the links to those nodes that + -- contain global information. At instantiation, the information from the + -- associated node is placed on the new copy, so that name resolution is + -- not repeated. + -- + -- Three kinds of source nodes have associated nodes: + -- + -- a) those that can reference (denote) entities, that is identifiers, + -- character literals, expanded_names, operator symbols, operators, + -- and attribute reference nodes. These nodes have an Entity field + -- and are the set of nodes that are in N_Has_Entity. + -- + -- b) aggregates (N_Aggregate and N_Extension_Aggregate) + -- + -- c) selected components (N_Selected_Component) + -- + -- For the first class, the associated node preserves the entity if it is + -- global. If the generic contains nested instantiations, the associated + -- node itself has been recopied, and a chain of them must be followed. + -- + -- For aggregates, the associated node allows retrieval of the type, which + -- may otherwise not appear in the generic. The view of this type may be + -- different between generic and instantiation, and the full view can be + -- installed before the instantiation is analyzed. For aggregates of type + -- extensions, the same view exchange may have to be performed for some of + -- the ancestor types, if their view is private at the point of + -- instantiation. + -- + -- Nodes that are selected components in the parse tree may be rewritten + -- as expanded names after resolution, and must be treated as potential + -- entity holders, which is why they also have an Associated_Node. + -- + -- Nodes that do not come from source, such as freeze nodes, do not appear + -- in the generic tree, and need not have an associated node. + -- + -- The associated node is stored in the Associated_Node field. Note that + -- this field overlaps Entity, which is fine, because the whole point is + -- that we don't need or want the normal Entity field in this situation. + + procedure Map_Formal_Package_Entities (Form : Entity_Id; Act : Entity_Id); + -- Within the generic part, entities in the formal package are + -- visible. To validate subsequent type declarations, indicate + -- the correspondence between the entities in the analyzed formal, + -- and the entities in the actual package. There are three packages + -- involved in the instantiation of a formal package: the parent + -- generic P1 which appears in the generic declaration, the fake + -- instantiation P2 which appears in the analyzed generic, and whose + -- visible entities may be used in subsequent formals, and the actual + -- P3 in the instance. To validate subsequent formals, me indicate + -- that the entities in P2 are mapped into those of P3. The mapping of + -- entities has to be done recursively for nested packages. + + procedure Move_Freeze_Nodes + (Out_Of : Entity_Id; + After : Node_Id; + L : List_Id); + -- Freeze nodes can be generated in the analysis of a generic unit, but + -- will not be seen by the back-end. It is necessary to move those nodes + -- to the enclosing scope if they freeze an outer entity. We place them + -- at the end of the enclosing generic package, which is semantically + -- neutral. + + procedure Preanalyze_Actuals (N : Node_Id); + -- Analyze actuals to perform name resolution. Full resolution is done + -- later, when the expected types are known, but names have to be captured + -- before installing parents of generics, that are not visible for the + -- actuals themselves. + + function True_Parent (N : Node_Id) return Node_Id; + -- For a subunit, return parent of corresponding stub, else return + -- parent of node. + + procedure Valid_Default_Attribute (Nam : Entity_Id; Def : Node_Id); + -- Verify that an attribute that appears as the default for a formal + -- subprogram is a function or procedure with the correct profile. + + ------------------------------------------- + -- Data Structures for Generic Renamings -- + ------------------------------------------- + + -- The map Generic_Renamings associates generic entities with their + -- corresponding actuals. Currently used to validate type instances. It + -- will eventually be used for all generic parameters to eliminate the + -- need for overload resolution in the instance. + + type Assoc_Ptr is new Int; + + Assoc_Null : constant Assoc_Ptr := -1; + + type Assoc is record + Gen_Id : Entity_Id; + Act_Id : Entity_Id; + Next_In_HTable : Assoc_Ptr; + end record; + + package Generic_Renamings is new Table.Table + (Table_Component_Type => Assoc, + Table_Index_Type => Assoc_Ptr, + Table_Low_Bound => 0, + Table_Initial => 10, + Table_Increment => 100, + Table_Name => "Generic_Renamings"); + + -- Variable to hold enclosing instantiation. When the environment is + -- saved for a subprogram inlining, the corresponding Act_Id is empty. + + Current_Instantiated_Parent : Assoc := (Empty, Empty, Assoc_Null); + + -- Hash table for associations + + HTable_Size : constant := 37; + type HTable_Range is range 0 .. HTable_Size - 1; + + procedure Set_Next_Assoc (E : Assoc_Ptr; Next : Assoc_Ptr); + function Next_Assoc (E : Assoc_Ptr) return Assoc_Ptr; + function Get_Gen_Id (E : Assoc_Ptr) return Entity_Id; + function Hash (F : Entity_Id) return HTable_Range; + + package Generic_Renamings_HTable is new GNAT.HTable.Static_HTable ( + Header_Num => HTable_Range, + Element => Assoc, + Elmt_Ptr => Assoc_Ptr, + Null_Ptr => Assoc_Null, + Set_Next => Set_Next_Assoc, + Next => Next_Assoc, + Key => Entity_Id, + Get_Key => Get_Gen_Id, + Hash => Hash, + Equal => "="); + + Exchanged_Views : Elist_Id; + -- This list holds the private views that have been exchanged during + -- instantiation to restore the visibility of the generic declaration. + -- (see comments above). After instantiation, the current visibility is + -- reestablished by means of a traversal of this list. + + Hidden_Entities : Elist_Id; + -- This list holds the entities of the current scope that are removed + -- from immediate visibility when instantiating a child unit. Their + -- visibility is restored in Remove_Parent. + + -- Because instantiations can be recursive, the following must be saved + -- on entry and restored on exit from an instantiation (spec or body). + -- This is done by the two procedures Save_Env and Restore_Env. For + -- package and subprogram instantiations (but not for the body instances) + -- the action of Save_Env is done in two steps: Init_Env is called before + -- Check_Generic_Child_Unit, because setting the parent instances requires + -- that the visibility data structures be properly initialized. Once the + -- generic is unit is validated, Set_Instance_Env completes Save_Env. + + Parent_Unit_Visible : Boolean := False; + -- Parent_Unit_Visible is used when the generic is a child unit, and + -- indicates whether the ultimate parent of the generic is visible in the + -- instantiation environment. It is used to reset the visibility of the + -- parent at the end of the instantiation (see Remove_Parent). + + Instance_Parent_Unit : Entity_Id := Empty; + -- This records the ultimate parent unit of an instance of a generic + -- child unit and is used in conjunction with Parent_Unit_Visible to + -- indicate the unit to which the Parent_Unit_Visible flag corresponds. + + type Instance_Env is record + Instantiated_Parent : Assoc; + Exchanged_Views : Elist_Id; + Hidden_Entities : Elist_Id; + Current_Sem_Unit : Unit_Number_Type; + Parent_Unit_Visible : Boolean := False; + Instance_Parent_Unit : Entity_Id := Empty; + Switches : Config_Switches_Type; + end record; + + package Instance_Envs is new Table.Table ( + Table_Component_Type => Instance_Env, + Table_Index_Type => Int, + Table_Low_Bound => 0, + Table_Initial => 32, + Table_Increment => 100, + Table_Name => "Instance_Envs"); + + procedure Restore_Private_Views + (Pack_Id : Entity_Id; + Is_Package : Boolean := True); + -- Restore the private views of external types, and unmark the generic + -- renamings of actuals, so that they become compatible subtypes again. + -- For subprograms, Pack_Id is the package constructed to hold the + -- renamings. + + procedure Switch_View (T : Entity_Id); + -- Switch the partial and full views of a type and its private + -- dependents (i.e. its subtypes and derived types). + + ------------------------------------ + -- Structures for Error Reporting -- + ------------------------------------ + + Instantiation_Node : Node_Id; + -- Used by subprograms that validate instantiation of formal parameters + -- where there might be no actual on which to place the error message. + -- Also used to locate the instantiation node for generic subunits. + + Instantiation_Error : exception; + -- When there is a semantic error in the generic parameter matching, + -- there is no point in continuing the instantiation, because the + -- number of cascaded errors is unpredictable. This exception aborts + -- the instantiation process altogether. + + S_Adjustment : Sloc_Adjustment; + -- Offset created for each node in an instantiation, in order to keep + -- track of the source position of the instantiation in each of its nodes. + -- A subsequent semantic error or warning on a construct of the instance + -- points to both places: the original generic node, and the point of + -- instantiation. See Sinput and Sinput.L for additional details. + + ------------------------------------------------------------ + -- Data structure for keeping track when inside a Generic -- + ------------------------------------------------------------ + + -- The following table is used to save values of the Inside_A_Generic + -- flag (see spec of Sem) when they are saved by Start_Generic. + + package Generic_Flags is new Table.Table ( + Table_Component_Type => Boolean, + Table_Index_Type => Int, + Table_Low_Bound => 0, + Table_Initial => 32, + Table_Increment => 200, + Table_Name => "Generic_Flags"); + + --------------------------- + -- Abandon_Instantiation -- + --------------------------- + + procedure Abandon_Instantiation (N : Node_Id) is + begin + Error_Msg_N ("\instantiation abandoned!", N); + raise Instantiation_Error; + end Abandon_Instantiation; + + -------------------------- + -- Analyze_Associations -- + -------------------------- + + function Analyze_Associations + (I_Node : Node_Id; + Formals : List_Id; + F_Copy : List_Id) return List_Id + is + Actuals_To_Freeze : constant Elist_Id := New_Elmt_List; + Assoc : constant List_Id := New_List; + Default_Actuals : constant Elist_Id := New_Elmt_List; + Gen_Unit : constant Entity_Id := + Defining_Entity (Parent (F_Copy)); + + Actuals : List_Id; + Actual : Node_Id; + Analyzed_Formal : Node_Id; + First_Named : Node_Id := Empty; + Formal : Node_Id; + Match : Node_Id; + Named : Node_Id; + Saved_Formal : Node_Id; + + Default_Formals : constant List_Id := New_List; + -- If an Others_Choice is present, some of the formals may be defaulted. + -- To simplify the treatment of visibility in an instance, we introduce + -- individual defaults for each such formal. These defaults are + -- appended to the list of associations and replace the Others_Choice. + + Found_Assoc : Node_Id; + -- Association for the current formal being match. Empty if there are + -- no remaining actuals, or if there is no named association with the + -- name of the formal. + + Is_Named_Assoc : Boolean; + Num_Matched : Int := 0; + Num_Actuals : Int := 0; + + Others_Present : Boolean := False; + Others_Choice : Node_Id := Empty; + -- In Ada 2005, indicates partial parameterization of a formal + -- package. As usual an other association must be last in the list. + + procedure Check_Overloaded_Formal_Subprogram (Formal : Entity_Id); + -- Apply RM 12.3 (9): if a formal subprogram is overloaded, the instance + -- cannot have a named association for it. AI05-0025 extends this rule + -- to formals of formal packages by AI05-0025, and it also applies to + -- box-initialized formals. + + function Has_Fully_Defined_Profile (Subp : Entity_Id) return Boolean; + -- Determine whether the parameter types and the return type of Subp + -- are fully defined at the point of instantiation. + + function Matching_Actual + (F : Entity_Id; + A_F : Entity_Id) return Node_Id; + -- Find actual that corresponds to a given a formal parameter. If the + -- actuals are positional, return the next one, if any. If the actuals + -- are named, scan the parameter associations to find the right one. + -- A_F is the corresponding entity in the analyzed generic,which is + -- placed on the selector name for ASIS use. + -- + -- In Ada 2005, a named association may be given with a box, in which + -- case Matching_Actual sets Found_Assoc to the generic association, + -- but return Empty for the actual itself. In this case the code below + -- creates a corresponding declaration for the formal. + + function Partial_Parameterization return Boolean; + -- Ada 2005: if no match is found for a given formal, check if the + -- association for it includes a box, or whether the associations + -- include an Others clause. + + procedure Process_Default (F : Entity_Id); + -- Add a copy of the declaration of generic formal F to the list of + -- associations, and add an explicit box association for F if there + -- is none yet, and the default comes from an Others_Choice. + + function Renames_Standard_Subprogram (Subp : Entity_Id) return Boolean; + -- Determine whether Subp renames one of the subprograms defined in the + -- generated package Standard. + + procedure Set_Analyzed_Formal; + -- Find the node in the generic copy that corresponds to a given formal. + -- The semantic information on this node is used to perform legality + -- checks on the actuals. Because semantic analysis can introduce some + -- anonymous entities or modify the declaration node itself, the + -- correspondence between the two lists is not one-one. In addition to + -- anonymous types, the presence a formal equality will introduce an + -- implicit declaration for the corresponding inequality. + + ---------------------------------------- + -- Check_Overloaded_Formal_Subprogram -- + ---------------------------------------- + + procedure Check_Overloaded_Formal_Subprogram (Formal : Entity_Id) is + Temp_Formal : Entity_Id; + + begin + Temp_Formal := First (Formals); + while Present (Temp_Formal) loop + if Nkind (Temp_Formal) in N_Formal_Subprogram_Declaration + and then Temp_Formal /= Formal + and then + Chars (Defining_Unit_Name (Specification (Formal))) = + Chars (Defining_Unit_Name (Specification (Temp_Formal))) + then + if Present (Found_Assoc) then + Error_Msg_N + ("named association not allowed for overloaded formal", + Found_Assoc); + + else + Error_Msg_N + ("named association not allowed for overloaded formal", + Others_Choice); + end if; + + Abandon_Instantiation (Instantiation_Node); + end if; + + Next (Temp_Formal); + end loop; + end Check_Overloaded_Formal_Subprogram; + + ------------------------------- + -- Has_Fully_Defined_Profile -- + ------------------------------- + + function Has_Fully_Defined_Profile (Subp : Entity_Id) return Boolean is + function Is_Fully_Defined_Type (Typ : Entity_Id) return Boolean; + -- Determine whethet type Typ is fully defined + + --------------------------- + -- Is_Fully_Defined_Type -- + --------------------------- + + function Is_Fully_Defined_Type (Typ : Entity_Id) return Boolean is + begin + -- A private type without a full view is not fully defined + + if Is_Private_Type (Typ) + and then No (Full_View (Typ)) + then + return False; + + -- An incomplete type is never fully defined + + elsif Is_Incomplete_Type (Typ) then + return False; + + -- All other types are fully defined + + else + return True; + end if; + end Is_Fully_Defined_Type; + + -- Local declarations + + Param : Entity_Id; + + -- Start of processing for Has_Fully_Defined_Profile + + begin + -- Check the parameters + + Param := First_Formal (Subp); + while Present (Param) loop + if not Is_Fully_Defined_Type (Etype (Param)) then + return False; + end if; + + Next_Formal (Param); + end loop; + + -- Check the return type + + return Is_Fully_Defined_Type (Etype (Subp)); + end Has_Fully_Defined_Profile; + + --------------------- + -- Matching_Actual -- + --------------------- + + function Matching_Actual + (F : Entity_Id; + A_F : Entity_Id) return Node_Id + is + Prev : Node_Id; + Act : Node_Id; + + begin + Is_Named_Assoc := False; + + -- End of list of purely positional parameters + + if No (Actual) or else Nkind (Actual) = N_Others_Choice then + Found_Assoc := Empty; + Act := Empty; + + -- Case of positional parameter corresponding to current formal + + elsif No (Selector_Name (Actual)) then + Found_Assoc := Actual; + Act := Explicit_Generic_Actual_Parameter (Actual); + Num_Matched := Num_Matched + 1; + Next (Actual); + + -- Otherwise scan list of named actuals to find the one with the + -- desired name. All remaining actuals have explicit names. + + else + Is_Named_Assoc := True; + Found_Assoc := Empty; + Act := Empty; + Prev := Empty; + + while Present (Actual) loop + if Chars (Selector_Name (Actual)) = Chars (F) then + Set_Entity (Selector_Name (Actual), A_F); + Set_Etype (Selector_Name (Actual), Etype (A_F)); + Generate_Reference (A_F, Selector_Name (Actual)); + Found_Assoc := Actual; + Act := Explicit_Generic_Actual_Parameter (Actual); + Num_Matched := Num_Matched + 1; + exit; + end if; + + Prev := Actual; + Next (Actual); + end loop; + + -- Reset for subsequent searches. In most cases the named + -- associations are in order. If they are not, we reorder them + -- to avoid scanning twice the same actual. This is not just a + -- question of efficiency: there may be multiple defaults with + -- boxes that have the same name. In a nested instantiation we + -- insert actuals for those defaults, and cannot rely on their + -- names to disambiguate them. + + if Actual = First_Named then + Next (First_Named); + + elsif Present (Actual) then + Insert_Before (First_Named, Remove_Next (Prev)); + end if; + + Actual := First_Named; + end if; + + if Is_Entity_Name (Act) and then Present (Entity (Act)) then + Set_Used_As_Generic_Actual (Entity (Act)); + end if; + + return Act; + end Matching_Actual; + + ------------------------------ + -- Partial_Parameterization -- + ------------------------------ + + function Partial_Parameterization return Boolean is + begin + return Others_Present + or else (Present (Found_Assoc) and then Box_Present (Found_Assoc)); + end Partial_Parameterization; + + --------------------- + -- Process_Default -- + --------------------- + + procedure Process_Default (F : Entity_Id) is + Loc : constant Source_Ptr := Sloc (I_Node); + F_Id : constant Entity_Id := Defining_Entity (F); + Decl : Node_Id; + Default : Node_Id; + Id : Entity_Id; + + begin + -- Append copy of formal declaration to associations, and create new + -- defining identifier for it. + + Decl := New_Copy_Tree (F); + Id := Make_Defining_Identifier (Sloc (F_Id), Chars (F_Id)); + + if Nkind (F) in N_Formal_Subprogram_Declaration then + Set_Defining_Unit_Name (Specification (Decl), Id); + + else + Set_Defining_Identifier (Decl, Id); + end if; + + Append (Decl, Assoc); + + if No (Found_Assoc) then + Default := + Make_Generic_Association (Loc, + Selector_Name => New_Occurrence_Of (Id, Loc), + Explicit_Generic_Actual_Parameter => Empty); + Set_Box_Present (Default); + Append (Default, Default_Formals); + end if; + end Process_Default; + + --------------------------------- + -- Renames_Standard_Subprogram -- + --------------------------------- + + function Renames_Standard_Subprogram (Subp : Entity_Id) return Boolean is + Id : Entity_Id; + + begin + Id := Alias (Subp); + while Present (Id) loop + if Scope (Id) = Standard_Standard then + return True; + end if; + + Id := Alias (Id); + end loop; + + return False; + end Renames_Standard_Subprogram; + + ------------------------- + -- Set_Analyzed_Formal -- + ------------------------- + + procedure Set_Analyzed_Formal is + Kind : Node_Kind; + + begin + while Present (Analyzed_Formal) loop + Kind := Nkind (Analyzed_Formal); + + case Nkind (Formal) is + + when N_Formal_Subprogram_Declaration => + exit when Kind in N_Formal_Subprogram_Declaration + and then + Chars + (Defining_Unit_Name (Specification (Formal))) = + Chars + (Defining_Unit_Name (Specification (Analyzed_Formal))); + + when N_Formal_Package_Declaration => + exit when Nkind_In (Kind, N_Formal_Package_Declaration, + N_Generic_Package_Declaration, + N_Package_Declaration); + + when N_Use_Package_Clause | N_Use_Type_Clause => exit; + + when others => + + -- Skip freeze nodes, and nodes inserted to replace + -- unrecognized pragmas. + + exit when + Kind not in N_Formal_Subprogram_Declaration + and then not Nkind_In (Kind, N_Subprogram_Declaration, + N_Freeze_Entity, + N_Null_Statement, + N_Itype_Reference) + and then Chars (Defining_Identifier (Formal)) = + Chars (Defining_Identifier (Analyzed_Formal)); + end case; + + Next (Analyzed_Formal); + end loop; + end Set_Analyzed_Formal; + + -- Start of processing for Analyze_Associations + + begin + Actuals := Generic_Associations (I_Node); + + if Present (Actuals) then + + -- Check for an Others choice, indicating a partial parameterization + -- for a formal package. + + Actual := First (Actuals); + while Present (Actual) loop + if Nkind (Actual) = N_Others_Choice then + Others_Present := True; + Others_Choice := Actual; + + if Present (Next (Actual)) then + Error_Msg_N ("others must be last association", Actual); + end if; + + -- This subprogram is used both for formal packages and for + -- instantiations. For the latter, associations must all be + -- explicit. + + if Nkind (I_Node) /= N_Formal_Package_Declaration + and then Comes_From_Source (I_Node) + then + Error_Msg_N + ("others association not allowed in an instance", + Actual); + end if; + + -- In any case, nothing to do after the others association + + exit; + + elsif Box_Present (Actual) + and then Comes_From_Source (I_Node) + and then Nkind (I_Node) /= N_Formal_Package_Declaration + then + Error_Msg_N + ("box association not allowed in an instance", Actual); + end if; + + Next (Actual); + end loop; + + -- If named associations are present, save first named association + -- (it may of course be Empty) to facilitate subsequent name search. + + First_Named := First (Actuals); + while Present (First_Named) + and then Nkind (First_Named) /= N_Others_Choice + and then No (Selector_Name (First_Named)) + loop + Num_Actuals := Num_Actuals + 1; + Next (First_Named); + end loop; + end if; + + Named := First_Named; + while Present (Named) loop + if Nkind (Named) /= N_Others_Choice + and then No (Selector_Name (Named)) + then + Error_Msg_N ("invalid positional actual after named one", Named); + Abandon_Instantiation (Named); + end if; + + -- A named association may lack an actual parameter, if it was + -- introduced for a default subprogram that turns out to be local + -- to the outer instantiation. + + if Nkind (Named) /= N_Others_Choice + and then Present (Explicit_Generic_Actual_Parameter (Named)) + then + Num_Actuals := Num_Actuals + 1; + end if; + + Next (Named); + end loop; + + if Present (Formals) then + Formal := First_Non_Pragma (Formals); + Analyzed_Formal := First_Non_Pragma (F_Copy); + + if Present (Actuals) then + Actual := First (Actuals); + + -- All formals should have default values + + else + Actual := Empty; + end if; + + while Present (Formal) loop + Set_Analyzed_Formal; + Saved_Formal := Next_Non_Pragma (Formal); + + case Nkind (Formal) is + when N_Formal_Object_Declaration => + Match := + Matching_Actual ( + Defining_Identifier (Formal), + Defining_Identifier (Analyzed_Formal)); + + if No (Match) and then Partial_Parameterization then + Process_Default (Formal); + else + Append_List + (Instantiate_Object (Formal, Match, Analyzed_Formal), + Assoc); + end if; + + when N_Formal_Type_Declaration => + Match := + Matching_Actual ( + Defining_Identifier (Formal), + Defining_Identifier (Analyzed_Formal)); + + if No (Match) then + if Partial_Parameterization then + Process_Default (Formal); + + else + Error_Msg_Sloc := Sloc (Gen_Unit); + Error_Msg_NE + ("missing actual&", + Instantiation_Node, + Defining_Identifier (Formal)); + Error_Msg_NE ("\in instantiation of & declared#", + Instantiation_Node, Gen_Unit); + Abandon_Instantiation (Instantiation_Node); + end if; + + else + Analyze (Match); + Append_List + (Instantiate_Type + (Formal, Match, Analyzed_Formal, Assoc), + Assoc); + + -- An instantiation is a freeze point for the actuals, + -- unless this is a rewritten formal package, or the + -- formal is an Ada 2012 formal incomplete type. + + if Nkind (I_Node) = N_Formal_Package_Declaration + or else + (Ada_Version >= Ada_2012 + and then + Ekind (Defining_Identifier (Analyzed_Formal)) = + E_Incomplete_Type) + then + null; + + else + Append_Elmt (Entity (Match), Actuals_To_Freeze); + end if; + end if; + + -- A remote access-to-class-wide type is not a legal actual + -- for a generic formal of an access type (E.2.2(17/2)). + -- In GNAT an exception to this rule is introduced when + -- the formal is marked as remote using implementation + -- defined aspect/pragma Remote_Access_Type. In that case + -- the actual must be remote as well. + + -- If the current instantiation is the construction of a + -- local copy for a formal package the actuals may be + -- defaulted, and there is no matching actual to check. + + if Nkind (Analyzed_Formal) = N_Formal_Type_Declaration + and then + Nkind (Formal_Type_Definition (Analyzed_Formal)) = + N_Access_To_Object_Definition + and then Present (Match) + then + declare + Formal_Ent : constant Entity_Id := + Defining_Identifier (Analyzed_Formal); + begin + if Is_Remote_Access_To_Class_Wide_Type (Entity (Match)) + = Is_Remote_Types (Formal_Ent) + then + -- Remoteness of formal and actual match + + null; + + elsif Is_Remote_Types (Formal_Ent) then + + -- Remote formal, non-remote actual + + Error_Msg_NE + ("actual for& must be remote", Match, Formal_Ent); + + else + -- Non-remote formal, remote actual + + Error_Msg_NE + ("actual for& may not be remote", + Match, Formal_Ent); + end if; + end; + end if; + + when N_Formal_Subprogram_Declaration => + Match := + Matching_Actual + (Defining_Unit_Name (Specification (Formal)), + Defining_Unit_Name (Specification (Analyzed_Formal))); + + -- If the formal subprogram has the same name as another + -- formal subprogram of the generic, then a named + -- association is illegal (12.3(9)). Exclude named + -- associations that are generated for a nested instance. + + if Present (Match) + and then Is_Named_Assoc + and then Comes_From_Source (Found_Assoc) + then + Check_Overloaded_Formal_Subprogram (Formal); + end if; + + -- If there is no corresponding actual, this may be case + -- of partial parameterization, or else the formal has a + -- default or a box. + + if No (Match) and then Partial_Parameterization then + Process_Default (Formal); + + if Nkind (I_Node) = N_Formal_Package_Declaration then + Check_Overloaded_Formal_Subprogram (Formal); + end if; + + else + Append_To (Assoc, + Instantiate_Formal_Subprogram + (Formal, Match, Analyzed_Formal)); + + -- An instantiation is a freeze point for the actuals, + -- unless this is a rewritten formal package. + + if Nkind (I_Node) /= N_Formal_Package_Declaration + and then Nkind (Match) = N_Identifier + and then Is_Subprogram (Entity (Match)) + + -- The actual subprogram may rename a routine defined + -- in Standard. Avoid freezing such renamings because + -- subprograms coming from Standard cannot be frozen. + + and then + not Renames_Standard_Subprogram (Entity (Match)) + + -- If the actual subprogram comes from a different + -- unit, it is already frozen, either by a body in + -- that unit or by the end of the declarative part + -- of the unit. This check avoids the freezing of + -- subprograms defined in Standard which are used + -- as generic actuals. + + and then In_Same_Code_Unit (Entity (Match), I_Node) + and then Has_Fully_Defined_Profile (Entity (Match)) + then + -- Mark the subprogram as having a delayed freeze + -- since this may be an out-of-order action. + + Set_Has_Delayed_Freeze (Entity (Match)); + Append_Elmt (Entity (Match), Actuals_To_Freeze); + end if; + end if; + + -- If this is a nested generic, preserve default for later + -- instantiations. + + if No (Match) + and then Box_Present (Formal) + then + Append_Elmt + (Defining_Unit_Name (Specification (Last (Assoc))), + Default_Actuals); + end if; + + when N_Formal_Package_Declaration => + Match := + Matching_Actual ( + Defining_Identifier (Formal), + Defining_Identifier (Original_Node (Analyzed_Formal))); + + if No (Match) then + if Partial_Parameterization then + Process_Default (Formal); + + else + Error_Msg_Sloc := Sloc (Gen_Unit); + Error_Msg_NE + ("missing actual&", + Instantiation_Node, Defining_Identifier (Formal)); + Error_Msg_NE ("\in instantiation of & declared#", + Instantiation_Node, Gen_Unit); + + Abandon_Instantiation (Instantiation_Node); + end if; + + else + Analyze (Match); + Append_List + (Instantiate_Formal_Package + (Formal, Match, Analyzed_Formal), + Assoc); + end if; + + -- For use type and use package appearing in the generic part, + -- we have already copied them, so we can just move them where + -- they belong (we mustn't recopy them since this would mess up + -- the Sloc values). + + when N_Use_Package_Clause | + N_Use_Type_Clause => + if Nkind (Original_Node (I_Node)) = + N_Formal_Package_Declaration + then + Append (New_Copy_Tree (Formal), Assoc); + else + Remove (Formal); + Append (Formal, Assoc); + end if; + + when others => + raise Program_Error; + + end case; + + Formal := Saved_Formal; + Next_Non_Pragma (Analyzed_Formal); + end loop; + + if Num_Actuals > Num_Matched then + Error_Msg_Sloc := Sloc (Gen_Unit); + + if Present (Selector_Name (Actual)) then + Error_Msg_NE + ("unmatched actual&", + Actual, Selector_Name (Actual)); + Error_Msg_NE ("\in instantiation of& declared#", + Actual, Gen_Unit); + else + Error_Msg_NE + ("unmatched actual in instantiation of& declared#", + Actual, Gen_Unit); + end if; + end if; + + elsif Present (Actuals) then + Error_Msg_N + ("too many actuals in generic instantiation", Instantiation_Node); + end if; + + -- An instantiation freezes all generic actuals. The only exceptions + -- to this are incomplete types and subprograms which are not fully + -- defined at the point of instantiation. + + declare + Elmt : Elmt_Id := First_Elmt (Actuals_To_Freeze); + begin + while Present (Elmt) loop + Freeze_Before (I_Node, Node (Elmt)); + Next_Elmt (Elmt); + end loop; + end; + + -- If there are default subprograms, normalize the tree by adding + -- explicit associations for them. This is required if the instance + -- appears within a generic. + + declare + Elmt : Elmt_Id; + Subp : Entity_Id; + New_D : Node_Id; + + begin + Elmt := First_Elmt (Default_Actuals); + while Present (Elmt) loop + if No (Actuals) then + Actuals := New_List; + Set_Generic_Associations (I_Node, Actuals); + end if; + + Subp := Node (Elmt); + New_D := + Make_Generic_Association (Sloc (Subp), + Selector_Name => New_Occurrence_Of (Subp, Sloc (Subp)), + Explicit_Generic_Actual_Parameter => + New_Occurrence_Of (Subp, Sloc (Subp))); + Mark_Rewrite_Insertion (New_D); + Append_To (Actuals, New_D); + Next_Elmt (Elmt); + end loop; + end; + + -- If this is a formal package, normalize the parameter list by adding + -- explicit box associations for the formals that are covered by an + -- Others_Choice. + + if not Is_Empty_List (Default_Formals) then + Append_List (Default_Formals, Formals); + end if; + + return Assoc; + end Analyze_Associations; + + ------------------------------- + -- Analyze_Formal_Array_Type -- + ------------------------------- + + procedure Analyze_Formal_Array_Type + (T : in out Entity_Id; + Def : Node_Id) + is + DSS : Node_Id; + + begin + -- Treated like a non-generic array declaration, with additional + -- semantic checks. + + Enter_Name (T); + + if Nkind (Def) = N_Constrained_Array_Definition then + DSS := First (Discrete_Subtype_Definitions (Def)); + while Present (DSS) loop + if Nkind_In (DSS, N_Subtype_Indication, + N_Range, + N_Attribute_Reference) + then + Error_Msg_N ("only a subtype mark is allowed in a formal", DSS); + end if; + + Next (DSS); + end loop; + end if; + + Array_Type_Declaration (T, Def); + Set_Is_Generic_Type (Base_Type (T)); + + if Ekind (Component_Type (T)) = E_Incomplete_Type + and then No (Full_View (Component_Type (T))) + then + Error_Msg_N ("premature usage of incomplete type", Def); + + -- Check that range constraint is not allowed on the component type + -- of a generic formal array type (AARM 12.5.3(3)) + + elsif Is_Internal (Component_Type (T)) + and then Present (Subtype_Indication (Component_Definition (Def))) + and then Nkind (Original_Node + (Subtype_Indication (Component_Definition (Def)))) = + N_Subtype_Indication + then + Error_Msg_N + ("in a formal, a subtype indication can only be " + & "a subtype mark (RM 12.5.3(3))", + Subtype_Indication (Component_Definition (Def))); + end if; + + end Analyze_Formal_Array_Type; + + --------------------------------------------- + -- Analyze_Formal_Decimal_Fixed_Point_Type -- + --------------------------------------------- + + -- As for other generic types, we create a valid type representation with + -- legal but arbitrary attributes, whose values are never considered + -- static. For all scalar types we introduce an anonymous base type, with + -- the same attributes. We choose the corresponding integer type to be + -- Standard_Integer. + -- Here and in other similar routines, the Sloc of the generated internal + -- type must be the same as the sloc of the defining identifier of the + -- formal type declaration, to provide proper source navigation. + + procedure Analyze_Formal_Decimal_Fixed_Point_Type + (T : Entity_Id; + Def : Node_Id) + is + Loc : constant Source_Ptr := Sloc (Def); + + Base : constant Entity_Id := + New_Internal_Entity + (E_Decimal_Fixed_Point_Type, + Current_Scope, + Sloc (Defining_Identifier (Parent (Def))), 'G'); + + Int_Base : constant Entity_Id := Standard_Integer; + Delta_Val : constant Ureal := Ureal_1; + Digs_Val : constant Uint := Uint_6; + + begin + Enter_Name (T); + + Set_Etype (Base, Base); + Set_Size_Info (Base, Int_Base); + Set_RM_Size (Base, RM_Size (Int_Base)); + Set_First_Rep_Item (Base, First_Rep_Item (Int_Base)); + Set_Digits_Value (Base, Digs_Val); + Set_Delta_Value (Base, Delta_Val); + Set_Small_Value (Base, Delta_Val); + Set_Scalar_Range (Base, + Make_Range (Loc, + Low_Bound => Make_Real_Literal (Loc, Ureal_1), + High_Bound => Make_Real_Literal (Loc, Ureal_1))); + + Set_Is_Generic_Type (Base); + Set_Parent (Base, Parent (Def)); + + Set_Ekind (T, E_Decimal_Fixed_Point_Subtype); + Set_Etype (T, Base); + Set_Size_Info (T, Int_Base); + Set_RM_Size (T, RM_Size (Int_Base)); + Set_First_Rep_Item (T, First_Rep_Item (Int_Base)); + Set_Digits_Value (T, Digs_Val); + Set_Delta_Value (T, Delta_Val); + Set_Small_Value (T, Delta_Val); + Set_Scalar_Range (T, Scalar_Range (Base)); + Set_Is_Constrained (T); + + Check_Restriction (No_Fixed_Point, Def); + end Analyze_Formal_Decimal_Fixed_Point_Type; + + ------------------------------------------- + -- Analyze_Formal_Derived_Interface_Type -- + ------------------------------------------- + + procedure Analyze_Formal_Derived_Interface_Type + (N : Node_Id; + T : Entity_Id; + Def : Node_Id) + is + Loc : constant Source_Ptr := Sloc (Def); + + begin + -- Rewrite as a type declaration of a derived type. This ensures that + -- the interface list and primitive operations are properly captured. + + Rewrite (N, + Make_Full_Type_Declaration (Loc, + Defining_Identifier => T, + Type_Definition => Def)); + Analyze (N); + Set_Is_Generic_Type (T); + end Analyze_Formal_Derived_Interface_Type; + + --------------------------------- + -- Analyze_Formal_Derived_Type -- + --------------------------------- + + procedure Analyze_Formal_Derived_Type + (N : Node_Id; + T : Entity_Id; + Def : Node_Id) + is + Loc : constant Source_Ptr := Sloc (Def); + Unk_Disc : constant Boolean := Unknown_Discriminants_Present (N); + New_N : Node_Id; + + begin + Set_Is_Generic_Type (T); + + if Private_Present (Def) then + New_N := + Make_Private_Extension_Declaration (Loc, + Defining_Identifier => T, + Discriminant_Specifications => Discriminant_Specifications (N), + Unknown_Discriminants_Present => Unk_Disc, + Subtype_Indication => Subtype_Mark (Def), + Interface_List => Interface_List (Def)); + + Set_Abstract_Present (New_N, Abstract_Present (Def)); + Set_Limited_Present (New_N, Limited_Present (Def)); + Set_Synchronized_Present (New_N, Synchronized_Present (Def)); + + else + New_N := + Make_Full_Type_Declaration (Loc, + Defining_Identifier => T, + Discriminant_Specifications => + Discriminant_Specifications (Parent (T)), + Type_Definition => + Make_Derived_Type_Definition (Loc, + Subtype_Indication => Subtype_Mark (Def))); + + Set_Abstract_Present + (Type_Definition (New_N), Abstract_Present (Def)); + Set_Limited_Present + (Type_Definition (New_N), Limited_Present (Def)); + end if; + + Rewrite (N, New_N); + Analyze (N); + + if Unk_Disc then + if not Is_Composite_Type (T) then + Error_Msg_N + ("unknown discriminants not allowed for elementary types", N); + else + Set_Has_Unknown_Discriminants (T); + Set_Is_Constrained (T, False); + end if; + end if; + + -- If the parent type has a known size, so does the formal, which makes + -- legal representation clauses that involve the formal. + + Set_Size_Known_At_Compile_Time + (T, Size_Known_At_Compile_Time (Entity (Subtype_Mark (Def)))); + end Analyze_Formal_Derived_Type; + + ---------------------------------- + -- Analyze_Formal_Discrete_Type -- + ---------------------------------- + + -- The operations defined for a discrete types are those of an enumeration + -- type. The size is set to an arbitrary value, for use in analyzing the + -- generic unit. + + procedure Analyze_Formal_Discrete_Type (T : Entity_Id; Def : Node_Id) is + Loc : constant Source_Ptr := Sloc (Def); + Lo : Node_Id; + Hi : Node_Id; + + Base : constant Entity_Id := + New_Internal_Entity + (E_Floating_Point_Type, Current_Scope, + Sloc (Defining_Identifier (Parent (Def))), 'G'); + + begin + Enter_Name (T); + Set_Ekind (T, E_Enumeration_Subtype); + Set_Etype (T, Base); + Init_Size (T, 8); + Init_Alignment (T); + Set_Is_Generic_Type (T); + Set_Is_Constrained (T); + + -- For semantic analysis, the bounds of the type must be set to some + -- non-static value. The simplest is to create attribute nodes for those + -- bounds, that refer to the type itself. These bounds are never + -- analyzed but serve as place-holders. + + Lo := + Make_Attribute_Reference (Loc, + Attribute_Name => Name_First, + Prefix => New_Occurrence_Of (T, Loc)); + Set_Etype (Lo, T); + + Hi := + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Last, + Prefix => New_Occurrence_Of (T, Loc)); + Set_Etype (Hi, T); + + Set_Scalar_Range (T, + Make_Range (Loc, + Low_Bound => Lo, + High_Bound => Hi)); + + Set_Ekind (Base, E_Enumeration_Type); + Set_Etype (Base, Base); + Init_Size (Base, 8); + Init_Alignment (Base); + Set_Is_Generic_Type (Base); + Set_Scalar_Range (Base, Scalar_Range (T)); + Set_Parent (Base, Parent (Def)); + end Analyze_Formal_Discrete_Type; + + ---------------------------------- + -- Analyze_Formal_Floating_Type -- + --------------------------------- + + procedure Analyze_Formal_Floating_Type (T : Entity_Id; Def : Node_Id) is + Base : constant Entity_Id := + New_Internal_Entity + (E_Floating_Point_Type, Current_Scope, + Sloc (Defining_Identifier (Parent (Def))), 'G'); + + begin + -- The various semantic attributes are taken from the predefined type + -- Float, just so that all of them are initialized. Their values are + -- never used because no constant folding or expansion takes place in + -- the generic itself. + + Enter_Name (T); + Set_Ekind (T, E_Floating_Point_Subtype); + Set_Etype (T, Base); + Set_Size_Info (T, (Standard_Float)); + Set_RM_Size (T, RM_Size (Standard_Float)); + Set_Digits_Value (T, Digits_Value (Standard_Float)); + Set_Scalar_Range (T, Scalar_Range (Standard_Float)); + Set_Is_Constrained (T); + + Set_Is_Generic_Type (Base); + Set_Etype (Base, Base); + Set_Size_Info (Base, (Standard_Float)); + Set_RM_Size (Base, RM_Size (Standard_Float)); + Set_Digits_Value (Base, Digits_Value (Standard_Float)); + Set_Scalar_Range (Base, Scalar_Range (Standard_Float)); + Set_Parent (Base, Parent (Def)); + + Check_Restriction (No_Floating_Point, Def); + end Analyze_Formal_Floating_Type; + + ----------------------------------- + -- Analyze_Formal_Interface_Type;-- + ----------------------------------- + + procedure Analyze_Formal_Interface_Type + (N : Node_Id; + T : Entity_Id; + Def : Node_Id) + is + Loc : constant Source_Ptr := Sloc (N); + New_N : Node_Id; + + begin + New_N := + Make_Full_Type_Declaration (Loc, + Defining_Identifier => T, + Type_Definition => Def); + + Rewrite (N, New_N); + Analyze (N); + Set_Is_Generic_Type (T); + end Analyze_Formal_Interface_Type; + + --------------------------------- + -- Analyze_Formal_Modular_Type -- + --------------------------------- + + procedure Analyze_Formal_Modular_Type (T : Entity_Id; Def : Node_Id) is + begin + -- Apart from their entity kind, generic modular types are treated like + -- signed integer types, and have the same attributes. + + Analyze_Formal_Signed_Integer_Type (T, Def); + Set_Ekind (T, E_Modular_Integer_Subtype); + Set_Ekind (Etype (T), E_Modular_Integer_Type); + + end Analyze_Formal_Modular_Type; + + --------------------------------------- + -- Analyze_Formal_Object_Declaration -- + --------------------------------------- + + procedure Analyze_Formal_Object_Declaration (N : Node_Id) is + E : constant Node_Id := Default_Expression (N); + Id : constant Node_Id := Defining_Identifier (N); + K : Entity_Kind; + T : Node_Id; + + begin + Enter_Name (Id); + + -- Determine the mode of the formal object + + if Out_Present (N) then + K := E_Generic_In_Out_Parameter; + + if not In_Present (N) then + Error_Msg_N ("formal generic objects cannot have mode OUT", N); + end if; + + else + K := E_Generic_In_Parameter; + end if; + + if Present (Subtype_Mark (N)) then + Find_Type (Subtype_Mark (N)); + T := Entity (Subtype_Mark (N)); + + -- Verify that there is no redundant null exclusion + + if Null_Exclusion_Present (N) then + if not Is_Access_Type (T) then + Error_Msg_N + ("null exclusion can only apply to an access type", N); + + elsif Can_Never_Be_Null (T) then + Error_Msg_NE + ("`NOT NULL` not allowed (& already excludes null)", + N, T); + end if; + end if; + + -- Ada 2005 (AI-423): Formal object with an access definition + + else + Check_Access_Definition (N); + T := Access_Definition + (Related_Nod => N, + N => Access_Definition (N)); + end if; + + if Ekind (T) = E_Incomplete_Type then + declare + Error_Node : Node_Id; + + begin + if Present (Subtype_Mark (N)) then + Error_Node := Subtype_Mark (N); + else + Check_Access_Definition (N); + Error_Node := Access_Definition (N); + end if; + + Error_Msg_N ("premature usage of incomplete type", Error_Node); + end; + end if; + + if K = E_Generic_In_Parameter then + + -- Ada 2005 (AI-287): Limited aggregates allowed in generic formals + + if Ada_Version < Ada_2005 and then Is_Limited_Type (T) then + Error_Msg_N + ("generic formal of mode IN must not be of limited type", N); + Explain_Limited_Type (T, N); + end if; + + if Is_Abstract_Type (T) then + Error_Msg_N + ("generic formal of mode IN must not be of abstract type", N); + end if; + + if Present (E) then + Preanalyze_Spec_Expression (E, T); + + if Is_Limited_Type (T) and then not OK_For_Limited_Init (T, E) then + Error_Msg_N + ("initialization not allowed for limited types", E); + Explain_Limited_Type (T, E); + end if; + end if; + + Set_Ekind (Id, K); + Set_Etype (Id, T); + + -- Case of generic IN OUT parameter + + else + -- If the formal has an unconstrained type, construct its actual + -- subtype, as is done for subprogram formals. In this fashion, all + -- its uses can refer to specific bounds. + + Set_Ekind (Id, K); + Set_Etype (Id, T); + + if (Is_Array_Type (T) + and then not Is_Constrained (T)) + or else + (Ekind (T) = E_Record_Type + and then Has_Discriminants (T)) + then + declare + Non_Freezing_Ref : constant Node_Id := + New_Occurrence_Of (Id, Sloc (Id)); + Decl : Node_Id; + + begin + -- Make sure the actual subtype doesn't generate bogus freezing + + Set_Must_Not_Freeze (Non_Freezing_Ref); + Decl := Build_Actual_Subtype (T, Non_Freezing_Ref); + Insert_Before_And_Analyze (N, Decl); + Set_Actual_Subtype (Id, Defining_Identifier (Decl)); + end; + else + Set_Actual_Subtype (Id, T); + end if; + + if Present (E) then + Error_Msg_N + ("initialization not allowed for `IN OUT` formals", N); + end if; + end if; + + if Has_Aspects (N) then + Analyze_Aspect_Specifications (N, Id); + end if; + end Analyze_Formal_Object_Declaration; + + ---------------------------------------------- + -- Analyze_Formal_Ordinary_Fixed_Point_Type -- + ---------------------------------------------- + + procedure Analyze_Formal_Ordinary_Fixed_Point_Type + (T : Entity_Id; + Def : Node_Id) + is + Loc : constant Source_Ptr := Sloc (Def); + Base : constant Entity_Id := + New_Internal_Entity + (E_Ordinary_Fixed_Point_Type, Current_Scope, + Sloc (Defining_Identifier (Parent (Def))), 'G'); + + begin + -- The semantic attributes are set for completeness only, their values + -- will never be used, since all properties of the type are non-static. + + Enter_Name (T); + Set_Ekind (T, E_Ordinary_Fixed_Point_Subtype); + Set_Etype (T, Base); + Set_Size_Info (T, Standard_Integer); + Set_RM_Size (T, RM_Size (Standard_Integer)); + Set_Small_Value (T, Ureal_1); + Set_Delta_Value (T, Ureal_1); + Set_Scalar_Range (T, + Make_Range (Loc, + Low_Bound => Make_Real_Literal (Loc, Ureal_1), + High_Bound => Make_Real_Literal (Loc, Ureal_1))); + Set_Is_Constrained (T); + + Set_Is_Generic_Type (Base); + Set_Etype (Base, Base); + Set_Size_Info (Base, Standard_Integer); + Set_RM_Size (Base, RM_Size (Standard_Integer)); + Set_Small_Value (Base, Ureal_1); + Set_Delta_Value (Base, Ureal_1); + Set_Scalar_Range (Base, Scalar_Range (T)); + Set_Parent (Base, Parent (Def)); + + Check_Restriction (No_Fixed_Point, Def); + end Analyze_Formal_Ordinary_Fixed_Point_Type; + + ---------------------------------------- + -- Analyze_Formal_Package_Declaration -- + ---------------------------------------- + + procedure Analyze_Formal_Package_Declaration (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Pack_Id : constant Entity_Id := Defining_Identifier (N); + Formal : Entity_Id; + Gen_Id : constant Node_Id := Name (N); + Gen_Decl : Node_Id; + Gen_Unit : Entity_Id; + New_N : Node_Id; + Parent_Installed : Boolean := False; + Renaming : Node_Id; + Parent_Instance : Entity_Id; + Renaming_In_Par : Entity_Id; + Associations : Boolean := True; + + Vis_Prims_List : Elist_Id := No_Elist; + -- List of primitives made temporarily visible in the instantiation + -- to match the visibility of the formal type + + function Build_Local_Package return Node_Id; + -- The formal package is rewritten so that its parameters are replaced + -- with corresponding declarations. For parameters with bona fide + -- associations these declarations are created by Analyze_Associations + -- as for a regular instantiation. For boxed parameters, we preserve + -- the formal declarations and analyze them, in order to introduce + -- entities of the right kind in the environment of the formal. + + ------------------------- + -- Build_Local_Package -- + ------------------------- + + function Build_Local_Package return Node_Id is + Decls : List_Id; + Pack_Decl : Node_Id; + + begin + -- Within the formal, the name of the generic package is a renaming + -- of the formal (as for a regular instantiation). + + Pack_Decl := + Make_Package_Declaration (Loc, + Specification => + Copy_Generic_Node + (Specification (Original_Node (Gen_Decl)), + Empty, Instantiating => True)); + + Renaming := Make_Package_Renaming_Declaration (Loc, + Defining_Unit_Name => + Make_Defining_Identifier (Loc, Chars (Gen_Unit)), + Name => New_Occurrence_Of (Formal, Loc)); + + if Nkind (Gen_Id) = N_Identifier + and then Chars (Gen_Id) = Chars (Pack_Id) + then + Error_Msg_NE + ("& is hidden within declaration of instance", Gen_Id, Gen_Unit); + end if; + + -- If the formal is declared with a box, or with an others choice, + -- create corresponding declarations for all entities in the formal + -- part, so that names with the proper types are available in the + -- specification of the formal package. + + -- On the other hand, if there are no associations, then all the + -- formals must have defaults, and this will be checked by the + -- call to Analyze_Associations. + + if Box_Present (N) + or else Nkind (First (Generic_Associations (N))) = N_Others_Choice + then + declare + Formal_Decl : Node_Id; + + begin + -- TBA : for a formal package, need to recurse ??? + + Decls := New_List; + Formal_Decl := + First + (Generic_Formal_Declarations (Original_Node (Gen_Decl))); + while Present (Formal_Decl) loop + Append_To + (Decls, Copy_Generic_Node (Formal_Decl, Empty, True)); + Next (Formal_Decl); + end loop; + end; + + -- If generic associations are present, use Analyze_Associations to + -- create the proper renaming declarations. + + else + declare + Act_Tree : constant Node_Id := + Copy_Generic_Node + (Original_Node (Gen_Decl), Empty, + Instantiating => True); + + begin + Generic_Renamings.Set_Last (0); + Generic_Renamings_HTable.Reset; + Instantiation_Node := N; + + Decls := + Analyze_Associations + (I_Node => Original_Node (N), + Formals => Generic_Formal_Declarations (Act_Tree), + F_Copy => Generic_Formal_Declarations (Gen_Decl)); + + Vis_Prims_List := Check_Hidden_Primitives (Decls); + end; + end if; + + Append (Renaming, To => Decls); + + -- Add generated declarations ahead of local declarations in + -- the package. + + if No (Visible_Declarations (Specification (Pack_Decl))) then + Set_Visible_Declarations (Specification (Pack_Decl), Decls); + else + Insert_List_Before + (First (Visible_Declarations (Specification (Pack_Decl))), + Decls); + end if; + + return Pack_Decl; + end Build_Local_Package; + + -- Start of processing for Analyze_Formal_Package_Declaration + + begin + Text_IO_Kludge (Gen_Id); + + Init_Env; + Check_Generic_Child_Unit (Gen_Id, Parent_Installed); + Gen_Unit := Entity (Gen_Id); + + -- Check for a formal package that is a package renaming + + if Present (Renamed_Object (Gen_Unit)) then + + -- Indicate that unit is used, before replacing it with renamed + -- entity for use below. + + if In_Extended_Main_Source_Unit (N) then + Set_Is_Instantiated (Gen_Unit); + Generate_Reference (Gen_Unit, N); + end if; + + Gen_Unit := Renamed_Object (Gen_Unit); + end if; + + if Ekind (Gen_Unit) /= E_Generic_Package then + Error_Msg_N ("expect generic package name", Gen_Id); + Restore_Env; + goto Leave; + + elsif Gen_Unit = Current_Scope then + Error_Msg_N + ("generic package cannot be used as a formal package of itself", + Gen_Id); + Restore_Env; + goto Leave; + + elsif In_Open_Scopes (Gen_Unit) then + if Is_Compilation_Unit (Gen_Unit) + and then Is_Child_Unit (Current_Scope) + then + -- Special-case the error when the formal is a parent, and + -- continue analysis to minimize cascaded errors. + + Error_Msg_N + ("generic parent cannot be used as formal package " + & "of a child unit", + Gen_Id); + + else + Error_Msg_N + ("generic package cannot be used as a formal package " + & "within itself", + Gen_Id); + Restore_Env; + goto Leave; + end if; + end if; + + -- Check that name of formal package does not hide name of generic, + -- or its leading prefix. This check must be done separately because + -- the name of the generic has already been analyzed. + + declare + Gen_Name : Entity_Id; + + begin + Gen_Name := Gen_Id; + while Nkind (Gen_Name) = N_Expanded_Name loop + Gen_Name := Prefix (Gen_Name); + end loop; + + if Chars (Gen_Name) = Chars (Pack_Id) then + Error_Msg_NE + ("& is hidden within declaration of formal package", + Gen_Id, Gen_Name); + end if; + end; + + if Box_Present (N) + or else No (Generic_Associations (N)) + or else Nkind (First (Generic_Associations (N))) = N_Others_Choice + then + Associations := False; + end if; + + -- If there are no generic associations, the generic parameters appear + -- as local entities and are instantiated like them. We copy the generic + -- package declaration as if it were an instantiation, and analyze it + -- like a regular package, except that we treat the formals as + -- additional visible components. + + Gen_Decl := Unit_Declaration_Node (Gen_Unit); + + if In_Extended_Main_Source_Unit (N) then + Set_Is_Instantiated (Gen_Unit); + Generate_Reference (Gen_Unit, N); + end if; + + Formal := New_Copy (Pack_Id); + Create_Instantiation_Source (N, Gen_Unit, False, S_Adjustment); + + begin + -- Make local generic without formals. The formals will be replaced + -- with internal declarations. + + New_N := Build_Local_Package; + + -- If there are errors in the parameter list, Analyze_Associations + -- raises Instantiation_Error. Patch the declaration to prevent + -- further exception propagation. + + exception + when Instantiation_Error => + + Enter_Name (Formal); + Set_Ekind (Formal, E_Variable); + Set_Etype (Formal, Any_Type); + Restore_Hidden_Primitives (Vis_Prims_List); + + if Parent_Installed then + Remove_Parent; + end if; + + goto Leave; + end; + + Rewrite (N, New_N); + Set_Defining_Unit_Name (Specification (New_N), Formal); + Set_Generic_Parent (Specification (N), Gen_Unit); + Set_Instance_Env (Gen_Unit, Formal); + Set_Is_Generic_Instance (Formal); + + Enter_Name (Formal); + Set_Ekind (Formal, E_Package); + Set_Etype (Formal, Standard_Void_Type); + Set_Inner_Instances (Formal, New_Elmt_List); + Push_Scope (Formal); + + if Is_Child_Unit (Gen_Unit) + and then Parent_Installed + then + -- Similarly, we have to make the name of the formal visible in the + -- parent instance, to resolve properly fully qualified names that + -- may appear in the generic unit. The parent instance has been + -- placed on the scope stack ahead of the current scope. + + Parent_Instance := Scope_Stack.Table (Scope_Stack.Last - 1).Entity; + + Renaming_In_Par := + Make_Defining_Identifier (Loc, Chars (Gen_Unit)); + Set_Ekind (Renaming_In_Par, E_Package); + Set_Etype (Renaming_In_Par, Standard_Void_Type); + Set_Scope (Renaming_In_Par, Parent_Instance); + Set_Parent (Renaming_In_Par, Parent (Formal)); + Set_Renamed_Object (Renaming_In_Par, Formal); + Append_Entity (Renaming_In_Par, Parent_Instance); + end if; + + Analyze (Specification (N)); + + -- The formals for which associations are provided are not visible + -- outside of the formal package. The others are still declared by a + -- formal parameter declaration. + + -- If there are no associations, the only local entity to hide is the + -- generated package renaming itself. + + declare + E : Entity_Id; + + begin + E := First_Entity (Formal); + while Present (E) loop + if Associations + and then not Is_Generic_Formal (E) + then + Set_Is_Hidden (E); + end if; + + if Ekind (E) = E_Package + and then Renamed_Entity (E) = Formal + then + Set_Is_Hidden (E); + exit; + end if; + + Next_Entity (E); + end loop; + end; + + End_Package_Scope (Formal); + Restore_Hidden_Primitives (Vis_Prims_List); + + if Parent_Installed then + Remove_Parent; + end if; + + Restore_Env; + + -- Inside the generic unit, the formal package is a regular package, but + -- no body is needed for it. Note that after instantiation, the defining + -- unit name we need is in the new tree and not in the original (see + -- Package_Instantiation). A generic formal package is an instance, and + -- can be used as an actual for an inner instance. + + Set_Has_Completion (Formal, True); + + -- Add semantic information to the original defining identifier. + -- for ASIS use. + + Set_Ekind (Pack_Id, E_Package); + Set_Etype (Pack_Id, Standard_Void_Type); + Set_Scope (Pack_Id, Scope (Formal)); + Set_Has_Completion (Pack_Id, True); + + <<Leave>> + if Has_Aspects (N) then + Analyze_Aspect_Specifications (N, Pack_Id); + end if; + end Analyze_Formal_Package_Declaration; + + --------------------------------- + -- Analyze_Formal_Private_Type -- + --------------------------------- + + procedure Analyze_Formal_Private_Type + (N : Node_Id; + T : Entity_Id; + Def : Node_Id) + is + begin + New_Private_Type (N, T, Def); + + -- Set the size to an arbitrary but legal value + + Set_Size_Info (T, Standard_Integer); + Set_RM_Size (T, RM_Size (Standard_Integer)); + end Analyze_Formal_Private_Type; + + ------------------------------------ + -- Analyze_Formal_Incomplete_Type -- + ------------------------------------ + + procedure Analyze_Formal_Incomplete_Type + (T : Entity_Id; + Def : Node_Id) + is + begin + Enter_Name (T); + Set_Ekind (T, E_Incomplete_Type); + Set_Etype (T, T); + Set_Private_Dependents (T, New_Elmt_List); + + if Tagged_Present (Def) then + Set_Is_Tagged_Type (T); + Make_Class_Wide_Type (T); + Set_Direct_Primitive_Operations (T, New_Elmt_List); + end if; + end Analyze_Formal_Incomplete_Type; + + ---------------------------------------- + -- Analyze_Formal_Signed_Integer_Type -- + ---------------------------------------- + + procedure Analyze_Formal_Signed_Integer_Type + (T : Entity_Id; + Def : Node_Id) + is + Base : constant Entity_Id := + New_Internal_Entity + (E_Signed_Integer_Type, + Current_Scope, + Sloc (Defining_Identifier (Parent (Def))), 'G'); + + begin + Enter_Name (T); + + Set_Ekind (T, E_Signed_Integer_Subtype); + Set_Etype (T, Base); + Set_Size_Info (T, Standard_Integer); + Set_RM_Size (T, RM_Size (Standard_Integer)); + Set_Scalar_Range (T, Scalar_Range (Standard_Integer)); + Set_Is_Constrained (T); + + Set_Is_Generic_Type (Base); + Set_Size_Info (Base, Standard_Integer); + Set_RM_Size (Base, RM_Size (Standard_Integer)); + Set_Etype (Base, Base); + Set_Scalar_Range (Base, Scalar_Range (Standard_Integer)); + Set_Parent (Base, Parent (Def)); + end Analyze_Formal_Signed_Integer_Type; + + ------------------------------------------- + -- Analyze_Formal_Subprogram_Declaration -- + ------------------------------------------- + + procedure Analyze_Formal_Subprogram_Declaration (N : Node_Id) is + Spec : constant Node_Id := Specification (N); + Def : constant Node_Id := Default_Name (N); + Nam : constant Entity_Id := Defining_Unit_Name (Spec); + Subp : Entity_Id; + + begin + if Nam = Error then + return; + end if; + + if Nkind (Nam) = N_Defining_Program_Unit_Name then + Error_Msg_N ("name of formal subprogram must be a direct name", Nam); + goto Leave; + end if; + + Analyze_Subprogram_Declaration (N); + Set_Is_Formal_Subprogram (Nam); + Set_Has_Completion (Nam); + + if Nkind (N) = N_Formal_Abstract_Subprogram_Declaration then + Set_Is_Abstract_Subprogram (Nam); + Set_Is_Dispatching_Operation (Nam); + + declare + Ctrl_Type : constant Entity_Id := Find_Dispatching_Type (Nam); + begin + if No (Ctrl_Type) then + Error_Msg_N + ("abstract formal subprogram must have a controlling type", + N); + + elsif Ada_Version >= Ada_2012 + and then Is_Incomplete_Type (Ctrl_Type) + then + Error_Msg_NE + ("controlling type of abstract formal subprogram cannot " & + "be incomplete type", N, Ctrl_Type); + + else + Check_Controlling_Formals (Ctrl_Type, Nam); + end if; + end; + end if; + + -- Default name is resolved at the point of instantiation + + if Box_Present (N) then + null; + + -- Else default is bound at the point of generic declaration + + elsif Present (Def) then + if Nkind (Def) = N_Operator_Symbol then + Find_Direct_Name (Def); + + elsif Nkind (Def) /= N_Attribute_Reference then + Analyze (Def); + + else + -- For an attribute reference, analyze the prefix and verify + -- that it has the proper profile for the subprogram. + + Analyze (Prefix (Def)); + Valid_Default_Attribute (Nam, Def); + goto Leave; + end if; + + -- Default name may be overloaded, in which case the interpretation + -- with the correct profile must be selected, as for a renaming. + -- If the definition is an indexed component, it must denote a + -- member of an entry family. If it is a selected component, it + -- can be a protected operation. + + if Etype (Def) = Any_Type then + goto Leave; + + elsif Nkind (Def) = N_Selected_Component then + if not Is_Overloadable (Entity (Selector_Name (Def))) then + Error_Msg_N ("expect valid subprogram name as default", Def); + end if; + + elsif Nkind (Def) = N_Indexed_Component then + if Is_Entity_Name (Prefix (Def)) then + if Ekind (Entity (Prefix (Def))) /= E_Entry_Family then + Error_Msg_N ("expect valid subprogram name as default", Def); + end if; + + elsif Nkind (Prefix (Def)) = N_Selected_Component then + if Ekind (Entity (Selector_Name (Prefix (Def)))) /= + E_Entry_Family + then + Error_Msg_N ("expect valid subprogram name as default", Def); + end if; + + else + Error_Msg_N ("expect valid subprogram name as default", Def); + goto Leave; + end if; + + elsif Nkind (Def) = N_Character_Literal then + + -- Needs some type checks: subprogram should be parameterless??? + + Resolve (Def, (Etype (Nam))); + + elsif not Is_Entity_Name (Def) + or else not Is_Overloadable (Entity (Def)) + then + Error_Msg_N ("expect valid subprogram name as default", Def); + goto Leave; + + elsif not Is_Overloaded (Def) then + Subp := Entity (Def); + + if Subp = Nam then + Error_Msg_N ("premature usage of formal subprogram", Def); + + elsif not Entity_Matches_Spec (Subp, Nam) then + Error_Msg_N ("no visible entity matches specification", Def); + end if; + + -- More than one interpretation, so disambiguate as for a renaming + + else + declare + I : Interp_Index; + I1 : Interp_Index := 0; + It : Interp; + It1 : Interp; + + begin + Subp := Any_Id; + Get_First_Interp (Def, I, It); + while Present (It.Nam) loop + if Entity_Matches_Spec (It.Nam, Nam) then + if Subp /= Any_Id then + It1 := Disambiguate (Def, I1, I, Etype (Subp)); + + if It1 = No_Interp then + Error_Msg_N ("ambiguous default subprogram", Def); + else + Subp := It1.Nam; + end if; + + exit; + + else + I1 := I; + Subp := It.Nam; + end if; + end if; + + Get_Next_Interp (I, It); + end loop; + end; + + if Subp /= Any_Id then + + -- Subprogram found, generate reference to it + + Set_Entity (Def, Subp); + Generate_Reference (Subp, Def); + + if Subp = Nam then + Error_Msg_N ("premature usage of formal subprogram", Def); + + elsif Ekind (Subp) /= E_Operator then + Check_Mode_Conformant (Subp, Nam); + end if; + + else + Error_Msg_N ("no visible subprogram matches specification", N); + end if; + end if; + end if; + + <<Leave>> + if Has_Aspects (N) then + Analyze_Aspect_Specifications (N, Nam); + end if; + + end Analyze_Formal_Subprogram_Declaration; + + ------------------------------------- + -- Analyze_Formal_Type_Declaration -- + ------------------------------------- + + procedure Analyze_Formal_Type_Declaration (N : Node_Id) is + Def : constant Node_Id := Formal_Type_Definition (N); + T : Entity_Id; + + begin + T := Defining_Identifier (N); + + if Present (Discriminant_Specifications (N)) + and then Nkind (Def) /= N_Formal_Private_Type_Definition + then + Error_Msg_N + ("discriminants not allowed for this formal type", T); + end if; + + -- Enter the new name, and branch to specific routine + + case Nkind (Def) is + when N_Formal_Private_Type_Definition => + Analyze_Formal_Private_Type (N, T, Def); + + when N_Formal_Derived_Type_Definition => + Analyze_Formal_Derived_Type (N, T, Def); + + when N_Formal_Incomplete_Type_Definition => + Analyze_Formal_Incomplete_Type (T, Def); + + when N_Formal_Discrete_Type_Definition => + Analyze_Formal_Discrete_Type (T, Def); + + when N_Formal_Signed_Integer_Type_Definition => + Analyze_Formal_Signed_Integer_Type (T, Def); + + when N_Formal_Modular_Type_Definition => + Analyze_Formal_Modular_Type (T, Def); + + when N_Formal_Floating_Point_Definition => + Analyze_Formal_Floating_Type (T, Def); + + when N_Formal_Ordinary_Fixed_Point_Definition => + Analyze_Formal_Ordinary_Fixed_Point_Type (T, Def); + + when N_Formal_Decimal_Fixed_Point_Definition => + Analyze_Formal_Decimal_Fixed_Point_Type (T, Def); + + when N_Array_Type_Definition => + Analyze_Formal_Array_Type (T, Def); + + when N_Access_To_Object_Definition | + N_Access_Function_Definition | + N_Access_Procedure_Definition => + Analyze_Generic_Access_Type (T, Def); + + -- Ada 2005: a interface declaration is encoded as an abstract + -- record declaration or a abstract type derivation. + + when N_Record_Definition => + Analyze_Formal_Interface_Type (N, T, Def); + + when N_Derived_Type_Definition => + Analyze_Formal_Derived_Interface_Type (N, T, Def); + + when N_Error => + null; + + when others => + raise Program_Error; + + end case; + + Set_Is_Generic_Type (T); + + if Has_Aspects (N) then + Analyze_Aspect_Specifications (N, T); + end if; + end Analyze_Formal_Type_Declaration; + + ------------------------------------ + -- Analyze_Function_Instantiation -- + ------------------------------------ + + procedure Analyze_Function_Instantiation (N : Node_Id) is + begin + Analyze_Subprogram_Instantiation (N, E_Function); + end Analyze_Function_Instantiation; + + --------------------------------- + -- Analyze_Generic_Access_Type -- + --------------------------------- + + procedure Analyze_Generic_Access_Type (T : Entity_Id; Def : Node_Id) is + begin + Enter_Name (T); + + if Nkind (Def) = N_Access_To_Object_Definition then + Access_Type_Declaration (T, Def); + + if Is_Incomplete_Or_Private_Type (Designated_Type (T)) + and then No (Full_View (Designated_Type (T))) + and then not Is_Generic_Type (Designated_Type (T)) + then + Error_Msg_N ("premature usage of incomplete type", Def); + + elsif not Is_Entity_Name (Subtype_Indication (Def)) then + Error_Msg_N + ("only a subtype mark is allowed in a formal", Def); + end if; + + else + Access_Subprogram_Declaration (T, Def); + end if; + end Analyze_Generic_Access_Type; + + --------------------------------- + -- Analyze_Generic_Formal_Part -- + --------------------------------- + + procedure Analyze_Generic_Formal_Part (N : Node_Id) is + Gen_Parm_Decl : Node_Id; + + begin + -- The generic formals are processed in the scope of the generic unit, + -- where they are immediately visible. The scope is installed by the + -- caller. + + Gen_Parm_Decl := First (Generic_Formal_Declarations (N)); + + while Present (Gen_Parm_Decl) loop + Analyze (Gen_Parm_Decl); + Next (Gen_Parm_Decl); + end loop; + + Generate_Reference_To_Generic_Formals (Current_Scope); + end Analyze_Generic_Formal_Part; + + ------------------------------------------ + -- Analyze_Generic_Package_Declaration -- + ------------------------------------------ + + procedure Analyze_Generic_Package_Declaration (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Id : Entity_Id; + New_N : Node_Id; + Save_Parent : Node_Id; + Renaming : Node_Id; + Decls : constant List_Id := + Visible_Declarations (Specification (N)); + Decl : Node_Id; + + begin + Check_SPARK_Restriction ("generic is not allowed", N); + + -- We introduce a renaming of the enclosing package, to have a usable + -- entity as the prefix of an expanded name for a local entity of the + -- form Par.P.Q, where P is the generic package. This is because a local + -- entity named P may hide it, so that the usual visibility rules in + -- the instance will not resolve properly. + + Renaming := + Make_Package_Renaming_Declaration (Loc, + Defining_Unit_Name => + Make_Defining_Identifier (Loc, + Chars => New_External_Name (Chars (Defining_Entity (N)), "GH")), + Name => Make_Identifier (Loc, Chars (Defining_Entity (N)))); + + if Present (Decls) then + Decl := First (Decls); + while Present (Decl) + and then Nkind (Decl) = N_Pragma + loop + Next (Decl); + end loop; + + if Present (Decl) then + Insert_Before (Decl, Renaming); + else + Append (Renaming, Visible_Declarations (Specification (N))); + end if; + + else + Set_Visible_Declarations (Specification (N), New_List (Renaming)); + end if; + + -- Create copy of generic unit, and save for instantiation. If the unit + -- is a child unit, do not copy the specifications for the parent, which + -- are not part of the generic tree. + + Save_Parent := Parent_Spec (N); + Set_Parent_Spec (N, Empty); + + New_N := Copy_Generic_Node (N, Empty, Instantiating => False); + Set_Parent_Spec (New_N, Save_Parent); + Rewrite (N, New_N); + + -- Once the contents of the generic copy and the template are swapped, + -- do the same for their respective aspect specifications. + + Exchange_Aspects (N, New_N); + Id := Defining_Entity (N); + Generate_Definition (Id); + + -- Expansion is not applied to generic units + + Start_Generic; + + Enter_Name (Id); + Set_Ekind (Id, E_Generic_Package); + Set_Etype (Id, Standard_Void_Type); + Set_Contract (Id, Make_Contract (Sloc (Id))); + + -- Analyze aspects now, so that generated pragmas appear in the + -- declarations before building and analyzing the generic copy. + + if Has_Aspects (N) then + Analyze_Aspect_Specifications (N, Id); + end if; + + Push_Scope (Id); + Enter_Generic_Scope (Id); + Set_Inner_Instances (Id, New_Elmt_List); + + Set_Categorization_From_Pragmas (N); + Set_Is_Pure (Id, Is_Pure (Current_Scope)); + + -- Link the declaration of the generic homonym in the generic copy to + -- the package it renames, so that it is always resolved properly. + + Set_Generic_Homonym (Id, Defining_Unit_Name (Renaming)); + Set_Entity (Associated_Node (Name (Renaming)), Id); + + -- For a library unit, we have reconstructed the entity for the unit, + -- and must reset it in the library tables. + + if Nkind (Parent (N)) = N_Compilation_Unit then + Set_Cunit_Entity (Current_Sem_Unit, Id); + end if; + + Analyze_Generic_Formal_Part (N); + + -- After processing the generic formals, analysis proceeds as for a + -- non-generic package. + + Analyze (Specification (N)); + + Validate_Categorization_Dependency (N, Id); + + End_Generic; + + End_Package_Scope (Id); + Exit_Generic_Scope (Id); + + if Nkind (Parent (N)) /= N_Compilation_Unit then + Move_Freeze_Nodes (Id, N, Visible_Declarations (Specification (N))); + Move_Freeze_Nodes (Id, N, Private_Declarations (Specification (N))); + Move_Freeze_Nodes (Id, N, Generic_Formal_Declarations (N)); + + else + Set_Body_Required (Parent (N), Unit_Requires_Body (Id)); + Validate_RT_RAT_Component (N); + + -- If this is a spec without a body, check that generic parameters + -- are referenced. + + if not Body_Required (Parent (N)) then + Check_References (Id); + end if; + end if; + end Analyze_Generic_Package_Declaration; + + -------------------------------------------- + -- Analyze_Generic_Subprogram_Declaration -- + -------------------------------------------- + + procedure Analyze_Generic_Subprogram_Declaration (N : Node_Id) is + Spec : Node_Id; + Id : Entity_Id; + Formals : List_Id; + New_N : Node_Id; + Result_Type : Entity_Id; + Save_Parent : Node_Id; + Typ : Entity_Id; + + begin + Check_SPARK_Restriction ("generic is not allowed", N); + + -- Create copy of generic unit, and save for instantiation. If the unit + -- is a child unit, do not copy the specifications for the parent, which + -- are not part of the generic tree. + + Save_Parent := Parent_Spec (N); + Set_Parent_Spec (N, Empty); + + New_N := Copy_Generic_Node (N, Empty, Instantiating => False); + Set_Parent_Spec (New_N, Save_Parent); + Rewrite (N, New_N); + + Check_SPARK_Mode_In_Generic (N); + + -- The aspect specifications are not attached to the tree, and must + -- be copied and attached to the generic copy explicitly. + + if Present (Aspect_Specifications (New_N)) then + declare + Aspects : constant List_Id := Aspect_Specifications (N); + begin + Set_Has_Aspects (N, False); + Move_Aspects (New_N, To => N); + Set_Has_Aspects (Original_Node (N), False); + Set_Aspect_Specifications (Original_Node (N), Aspects); + end; + end if; + + Spec := Specification (N); + Id := Defining_Entity (Spec); + Generate_Definition (Id); + Set_Contract (Id, Make_Contract (Sloc (Id))); + + if Nkind (Id) = N_Defining_Operator_Symbol then + Error_Msg_N + ("operator symbol not allowed for generic subprogram", Id); + end if; + + Start_Generic; + + Enter_Name (Id); + + Set_Scope_Depth_Value (Id, Scope_Depth (Current_Scope) + 1); + Push_Scope (Id); + Enter_Generic_Scope (Id); + Set_Inner_Instances (Id, New_Elmt_List); + Set_Is_Pure (Id, Is_Pure (Current_Scope)); + + Analyze_Generic_Formal_Part (N); + + Formals := Parameter_Specifications (Spec); + + if Present (Formals) then + Process_Formals (Formals, Spec); + end if; + + if Nkind (Spec) = N_Function_Specification then + Set_Ekind (Id, E_Generic_Function); + + if Nkind (Result_Definition (Spec)) = N_Access_Definition then + Result_Type := Access_Definition (Spec, Result_Definition (Spec)); + Set_Etype (Id, Result_Type); + + -- Check restriction imposed by AI05-073: a generic function + -- cannot return an abstract type or an access to such. + + -- This is a binding interpretation should it apply to earlier + -- versions of Ada as well as Ada 2012??? + + if Is_Abstract_Type (Designated_Type (Result_Type)) + and then Ada_Version >= Ada_2012 + then + Error_Msg_N ("generic function cannot have an access result" + & " that designates an abstract type", Spec); + end if; + + else + Find_Type (Result_Definition (Spec)); + Typ := Entity (Result_Definition (Spec)); + + if Is_Abstract_Type (Typ) + and then Ada_Version >= Ada_2012 + then + Error_Msg_N + ("generic function cannot have abstract result type", Spec); + end if; + + -- If a null exclusion is imposed on the result type, then create + -- a null-excluding itype (an access subtype) and use it as the + -- function's Etype. + + if Is_Access_Type (Typ) + and then Null_Exclusion_Present (Spec) + then + Set_Etype (Id, + Create_Null_Excluding_Itype + (T => Typ, + Related_Nod => Spec, + Scope_Id => Defining_Unit_Name (Spec))); + else + Set_Etype (Id, Typ); + end if; + end if; + + else + Set_Ekind (Id, E_Generic_Procedure); + Set_Etype (Id, Standard_Void_Type); + end if; + + -- For a library unit, we have reconstructed the entity for the unit, + -- and must reset it in the library tables. We also make sure that + -- Body_Required is set properly in the original compilation unit node. + + if Nkind (Parent (N)) = N_Compilation_Unit then + Set_Cunit_Entity (Current_Sem_Unit, Id); + Set_Body_Required (Parent (N), Unit_Requires_Body (Id)); + end if; + + Set_Categorization_From_Pragmas (N); + Validate_Categorization_Dependency (N, Id); + + Save_Global_References (Original_Node (N)); + + -- For ASIS purposes, convert any postcondition, precondition pragmas + -- into aspects, if N is not a compilation unit by itself, in order to + -- enable the analysis of expressions inside the corresponding PPC + -- pragmas. + + if ASIS_Mode and then Is_List_Member (N) then + Make_Aspect_For_PPC_In_Gen_Sub_Decl (N); + end if; + + -- To capture global references, analyze the expressions of aspects, + -- and propagate information to original tree. Note that in this case + -- analysis of attributes is not delayed until the freeze point. + + -- It seems very hard to recreate the proper visibility of the generic + -- subprogram at a later point because the analysis of an aspect may + -- create pragmas after the generic copies have been made ??? + + if Has_Aspects (N) then + declare + Aspect : Node_Id; + + begin + Aspect := First (Aspect_Specifications (N)); + while Present (Aspect) loop + if Get_Aspect_Id (Aspect) /= Aspect_Warnings + and then Present (Expression (Aspect)) + then + Analyze (Expression (Aspect)); + end if; + + Next (Aspect); + end loop; + + Aspect := First (Aspect_Specifications (Original_Node (N))); + while Present (Aspect) loop + if Present (Expression (Aspect)) then + Save_Global_References (Expression (Aspect)); + end if; + + Next (Aspect); + end loop; + end; + end if; + + End_Generic; + End_Scope; + Exit_Generic_Scope (Id); + Generate_Reference_To_Formals (Id); + + List_Inherited_Pre_Post_Aspects (Id); + end Analyze_Generic_Subprogram_Declaration; + + ----------------------------------- + -- Analyze_Package_Instantiation -- + ----------------------------------- + + procedure Analyze_Package_Instantiation (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Gen_Id : constant Node_Id := Name (N); + + Act_Decl : Node_Id; + Act_Decl_Name : Node_Id; + Act_Decl_Id : Entity_Id; + Act_Spec : Node_Id; + Act_Tree : Node_Id; + + Gen_Decl : Node_Id; + Gen_Unit : Entity_Id; + + Is_Actual_Pack : constant Boolean := + Is_Internal (Defining_Entity (N)); + + Env_Installed : Boolean := False; + Parent_Installed : Boolean := False; + Renaming_List : List_Id; + Unit_Renaming : Node_Id; + Needs_Body : Boolean; + Inline_Now : Boolean := False; + + Save_Style_Check : constant Boolean := Style_Check; + -- Save style check mode for restore on exit + + procedure Delay_Descriptors (E : Entity_Id); + -- Delay generation of subprogram descriptors for given entity + + function Might_Inline_Subp return Boolean; + -- If inlining is active and the generic contains inlined subprograms, + -- we instantiate the body. This may cause superfluous instantiations, + -- but it is simpler than detecting the need for the body at the point + -- of inlining, when the context of the instance is not available. + + function Must_Inline_Subp return Boolean; + -- If inlining is active and the generic contains inlined subprograms, + -- return True if some of the inlined subprograms must be inlined by + -- the frontend. + + ----------------------- + -- Delay_Descriptors -- + ----------------------- + + procedure Delay_Descriptors (E : Entity_Id) is + begin + if not Delay_Subprogram_Descriptors (E) then + Set_Delay_Subprogram_Descriptors (E); + Pending_Descriptor.Append (E); + end if; + end Delay_Descriptors; + + ----------------------- + -- Might_Inline_Subp -- + ----------------------- + + function Might_Inline_Subp return Boolean is + E : Entity_Id; + + begin + if not Inline_Processing_Required then + return False; + + else + E := First_Entity (Gen_Unit); + while Present (E) loop + if Is_Subprogram (E) + and then Is_Inlined (E) + then + return True; + end if; + + Next_Entity (E); + end loop; + end if; + + return False; + end Might_Inline_Subp; + + ---------------------- + -- Must_Inline_Subp -- + ---------------------- + + function Must_Inline_Subp return Boolean is + E : Entity_Id; + + begin + if not Inline_Processing_Required then + return False; + + else + E := First_Entity (Gen_Unit); + while Present (E) loop + if Is_Subprogram (E) + and then Is_Inlined (E) + and then Must_Inline (E) + then + return True; + end if; + + Next_Entity (E); + end loop; + end if; + + return False; + end Must_Inline_Subp; + + -- Local declarations + + Vis_Prims_List : Elist_Id := No_Elist; + -- List of primitives made temporarily visible in the instantiation + -- to match the visibility of the formal type + + -- Start of processing for Analyze_Package_Instantiation + + begin + Check_SPARK_Restriction ("generic is not allowed", N); + + -- Very first thing: apply the special kludge for Text_IO processing + -- in case we are instantiating one of the children of [Wide_]Text_IO. + + Text_IO_Kludge (Name (N)); + + -- Make node global for error reporting + + Instantiation_Node := N; + + -- Turn off style checking in instances. If the check is enabled on the + -- generic unit, a warning in an instance would just be noise. If not + -- enabled on the generic, then a warning in an instance is just wrong. + + Style_Check := False; + + -- Case of instantiation of a generic package + + if Nkind (N) = N_Package_Instantiation then + Act_Decl_Id := New_Copy (Defining_Entity (N)); + Set_Comes_From_Source (Act_Decl_Id, True); + + if Nkind (Defining_Unit_Name (N)) = N_Defining_Program_Unit_Name then + Act_Decl_Name := + Make_Defining_Program_Unit_Name (Loc, + Name => New_Copy_Tree (Name (Defining_Unit_Name (N))), + Defining_Identifier => Act_Decl_Id); + else + Act_Decl_Name := Act_Decl_Id; + end if; + + -- Case of instantiation of a formal package + + else + Act_Decl_Id := Defining_Identifier (N); + Act_Decl_Name := Act_Decl_Id; + end if; + + Generate_Definition (Act_Decl_Id); + Preanalyze_Actuals (N); + + Init_Env; + Env_Installed := True; + + -- Reset renaming map for formal types. The mapping is established + -- when analyzing the generic associations, but some mappings are + -- inherited from formal packages of parent units, and these are + -- constructed when the parents are installed. + + Generic_Renamings.Set_Last (0); + Generic_Renamings_HTable.Reset; + + Check_Generic_Child_Unit (Gen_Id, Parent_Installed); + Gen_Unit := Entity (Gen_Id); + + -- Verify that it is the name of a generic package + + -- A visibility glitch: if the instance is a child unit and the generic + -- is the generic unit of a parent instance (i.e. both the parent and + -- the child units are instances of the same package) the name now + -- denotes the renaming within the parent, not the intended generic + -- unit. See if there is a homonym that is the desired generic. The + -- renaming declaration must be visible inside the instance of the + -- child, but not when analyzing the name in the instantiation itself. + + if Ekind (Gen_Unit) = E_Package + and then Present (Renamed_Entity (Gen_Unit)) + and then In_Open_Scopes (Renamed_Entity (Gen_Unit)) + and then Is_Generic_Instance (Renamed_Entity (Gen_Unit)) + and then Present (Homonym (Gen_Unit)) + then + Gen_Unit := Homonym (Gen_Unit); + end if; + + if Etype (Gen_Unit) = Any_Type then + Restore_Env; + goto Leave; + + elsif Ekind (Gen_Unit) /= E_Generic_Package then + + -- Ada 2005 (AI-50217): Cannot use instance in limited with_clause + + if From_Limited_With (Gen_Unit) then + Error_Msg_N + ("cannot instantiate a limited withed package", Gen_Id); + else + Error_Msg_NE + ("& is not the name of a generic package", Gen_Id, Gen_Unit); + end if; + + Restore_Env; + goto Leave; + end if; + + if In_Extended_Main_Source_Unit (N) then + Set_Is_Instantiated (Gen_Unit); + Generate_Reference (Gen_Unit, N); + + if Present (Renamed_Object (Gen_Unit)) then + Set_Is_Instantiated (Renamed_Object (Gen_Unit)); + Generate_Reference (Renamed_Object (Gen_Unit), N); + end if; + end if; + + if Nkind (Gen_Id) = N_Identifier + and then Chars (Gen_Unit) = Chars (Defining_Entity (N)) + then + Error_Msg_NE + ("& is hidden within declaration of instance", Gen_Id, Gen_Unit); + + elsif Nkind (Gen_Id) = N_Expanded_Name + and then Is_Child_Unit (Gen_Unit) + and then Nkind (Prefix (Gen_Id)) = N_Identifier + and then Chars (Act_Decl_Id) = Chars (Prefix (Gen_Id)) + then + Error_Msg_N + ("& is hidden within declaration of instance ", Prefix (Gen_Id)); + end if; + + Set_Entity (Gen_Id, Gen_Unit); + + -- If generic is a renaming, get original generic unit + + if Present (Renamed_Object (Gen_Unit)) + and then Ekind (Renamed_Object (Gen_Unit)) = E_Generic_Package + then + Gen_Unit := Renamed_Object (Gen_Unit); + end if; + + -- Verify that there are no circular instantiations + + if In_Open_Scopes (Gen_Unit) then + Error_Msg_NE ("instantiation of & within itself", N, Gen_Unit); + Restore_Env; + goto Leave; + + elsif Contains_Instance_Of (Gen_Unit, Current_Scope, Gen_Id) then + Error_Msg_Node_2 := Current_Scope; + Error_Msg_NE + ("circular Instantiation: & instantiated in &!", N, Gen_Unit); + Circularity_Detected := True; + Restore_Env; + goto Leave; + + else + Gen_Decl := Unit_Declaration_Node (Gen_Unit); + + -- Initialize renamings map, for error checking, and the list that + -- holds private entities whose views have changed between generic + -- definition and instantiation. If this is the instance created to + -- validate an actual package, the instantiation environment is that + -- of the enclosing instance. + + Create_Instantiation_Source (N, Gen_Unit, False, S_Adjustment); + + -- Copy original generic tree, to produce text for instantiation + + Act_Tree := + Copy_Generic_Node + (Original_Node (Gen_Decl), Empty, Instantiating => True); + + Act_Spec := Specification (Act_Tree); + + -- If this is the instance created to validate an actual package, + -- only the formals matter, do not examine the package spec itself. + + if Is_Actual_Pack then + Set_Visible_Declarations (Act_Spec, New_List); + Set_Private_Declarations (Act_Spec, New_List); + end if; + + Renaming_List := + Analyze_Associations + (I_Node => N, + Formals => Generic_Formal_Declarations (Act_Tree), + F_Copy => Generic_Formal_Declarations (Gen_Decl)); + + Vis_Prims_List := Check_Hidden_Primitives (Renaming_List); + + Set_Instance_Env (Gen_Unit, Act_Decl_Id); + Set_Defining_Unit_Name (Act_Spec, Act_Decl_Name); + Set_Is_Generic_Instance (Act_Decl_Id); + + Set_Generic_Parent (Act_Spec, Gen_Unit); + + -- References to the generic in its own declaration or its body are + -- references to the instance. Add a renaming declaration for the + -- generic unit itself. This declaration, as well as the renaming + -- declarations for the generic formals, must remain private to the + -- unit: the formals, because this is the language semantics, and + -- the unit because its use is an artifact of the implementation. + + Unit_Renaming := + Make_Package_Renaming_Declaration (Loc, + Defining_Unit_Name => + Make_Defining_Identifier (Loc, Chars (Gen_Unit)), + Name => New_Occurrence_Of (Act_Decl_Id, Loc)); + + Append (Unit_Renaming, Renaming_List); + + -- The renaming declarations are the first local declarations of the + -- new unit. + + if Is_Non_Empty_List (Visible_Declarations (Act_Spec)) then + Insert_List_Before + (First (Visible_Declarations (Act_Spec)), Renaming_List); + else + Set_Visible_Declarations (Act_Spec, Renaming_List); + end if; + + Act_Decl := + Make_Package_Declaration (Loc, + Specification => Act_Spec); + + -- Propagate the aspect specifications from the package declaration + -- template to the instantiated version of the package declaration. + + if Has_Aspects (Act_Tree) then + Set_Aspect_Specifications (Act_Decl, + New_Copy_List_Tree (Aspect_Specifications (Act_Tree))); + end if; + + -- Save the instantiation node, for subsequent instantiation of the + -- body, if there is one and we are generating code for the current + -- unit. Mark unit as having a body (avoids premature error message). + + -- We instantiate the body if we are generating code, if we are + -- generating cross-reference information, or if we are building + -- trees for ASIS use or GNATprove use. + + declare + Enclosing_Body_Present : Boolean := False; + -- If the generic unit is not a compilation unit, then a body may + -- be present in its parent even if none is required. We create a + -- tentative pending instantiation for the body, which will be + -- discarded if none is actually present. + + Scop : Entity_Id; + + begin + if Scope (Gen_Unit) /= Standard_Standard + and then not Is_Child_Unit (Gen_Unit) + then + Scop := Scope (Gen_Unit); + + while Present (Scop) + and then Scop /= Standard_Standard + loop + if Unit_Requires_Body (Scop) then + Enclosing_Body_Present := True; + exit; + + elsif In_Open_Scopes (Scop) + and then In_Package_Body (Scop) + then + Enclosing_Body_Present := True; + exit; + end if; + + exit when Is_Compilation_Unit (Scop); + Scop := Scope (Scop); + end loop; + end if; + + -- If front-end inlining is enabled, and this is a unit for which + -- code will be generated, we instantiate the body at once. + + -- This is done if the instance is not the main unit, and if the + -- generic is not a child unit of another generic, to avoid scope + -- problems and the reinstallation of parent instances. + + if Expander_Active + and then (not Is_Child_Unit (Gen_Unit) + or else not Is_Generic_Unit (Scope (Gen_Unit))) + and then Might_Inline_Subp + and then not Is_Actual_Pack + then + if not Debug_Flag_Dot_K + and then Front_End_Inlining + and then (Is_In_Main_Unit (N) + or else In_Main_Context (Current_Scope)) + and then Nkind (Parent (N)) /= N_Compilation_Unit + then + Inline_Now := True; + + elsif Debug_Flag_Dot_K + and then Must_Inline_Subp + and then (Is_In_Main_Unit (N) + or else In_Main_Context (Current_Scope)) + and then Nkind (Parent (N)) /= N_Compilation_Unit + then + Inline_Now := True; + + -- In configurable_run_time mode we force the inlining of + -- predefined subprograms marked Inline_Always, to minimize + -- the use of the run-time library. + + elsif Is_Predefined_File_Name + (Unit_File_Name (Get_Source_Unit (Gen_Decl))) + and then Configurable_Run_Time_Mode + and then Nkind (Parent (N)) /= N_Compilation_Unit + then + Inline_Now := True; + end if; + + -- If the current scope is itself an instance within a child + -- unit, there will be duplications in the scope stack, and the + -- unstacking mechanism in Inline_Instance_Body will fail. + -- This loses some rare cases of optimization, and might be + -- improved some day, if we can find a proper abstraction for + -- "the complete compilation context" that can be saved and + -- restored. ??? + + if Is_Generic_Instance (Current_Scope) then + declare + Curr_Unit : constant Entity_Id := + Cunit_Entity (Current_Sem_Unit); + begin + if Curr_Unit /= Current_Scope + and then Is_Child_Unit (Curr_Unit) + then + Inline_Now := False; + end if; + end; + end if; + end if; + + Needs_Body := + (Unit_Requires_Body (Gen_Unit) + or else Enclosing_Body_Present + or else Present (Corresponding_Body (Gen_Decl))) + and then (Is_In_Main_Unit (N) or else Might_Inline_Subp) + and then not Is_Actual_Pack + and then not Inline_Now + and then (Operating_Mode = Generate_Code + + -- Need comment for this check ??? + + or else (Operating_Mode = Check_Semantics + and then (ASIS_Mode or GNATprove_Mode))); + + -- If front_end_inlining is enabled, do not instantiate body if + -- within a generic context. + + if (Front_End_Inlining and then not Expander_Active) + or else Is_Generic_Unit (Cunit_Entity (Main_Unit)) + then + Needs_Body := False; + end if; + + -- If the current context is generic, and the package being + -- instantiated is declared within a formal package, there is no + -- body to instantiate until the enclosing generic is instantiated + -- and there is an actual for the formal package. If the formal + -- package has parameters, we build a regular package instance for + -- it, that precedes the original formal package declaration. + + if In_Open_Scopes (Scope (Scope (Gen_Unit))) then + declare + Decl : constant Node_Id := + Original_Node + (Unit_Declaration_Node (Scope (Gen_Unit))); + begin + if Nkind (Decl) = N_Formal_Package_Declaration + or else (Nkind (Decl) = N_Package_Declaration + and then Is_List_Member (Decl) + and then Present (Next (Decl)) + and then + Nkind (Next (Decl)) = + N_Formal_Package_Declaration) + then + Needs_Body := False; + end if; + end; + end if; + end; + + -- For RCI unit calling stubs, we omit the instance body if the + -- instance is the RCI library unit itself. + + -- However there is a special case for nested instances: in this case + -- we do generate the instance body, as it might be required, e.g. + -- because it provides stream attributes for some type used in the + -- profile of a remote subprogram. This is consistent with 12.3(12), + -- which indicates that the instance body occurs at the place of the + -- instantiation, and thus is part of the RCI declaration, which is + -- present on all client partitions (this is E.2.3(18)). + + -- Note that AI12-0002 may make it illegal at some point to have + -- stream attributes defined in an RCI unit, in which case this + -- special case will become unnecessary. In the meantime, there + -- is known application code in production that depends on this + -- being possible, so we definitely cannot eliminate the body in + -- the case of nested instances for the time being. + + -- When we generate a nested instance body, calling stubs for any + -- relevant subprogram will be be inserted immediately after the + -- subprogram declarations, and will take precedence over the + -- subsequent (original) body. (The stub and original body will be + -- complete homographs, but this is permitted in an instance). + -- (Could we do better and remove the original body???) + + if Distribution_Stub_Mode = Generate_Caller_Stub_Body + and then Comes_From_Source (N) + and then Nkind (Parent (N)) = N_Compilation_Unit + then + Needs_Body := False; + end if; + + if Needs_Body then + + -- Here is a defence against a ludicrous number of instantiations + -- caused by a circular set of instantiation attempts. + + if Pending_Instantiations.Last > Maximum_Instantiations then + Error_Msg_Uint_1 := UI_From_Int (Maximum_Instantiations); + Error_Msg_N ("too many instantiations, exceeds max of^", N); + Error_Msg_N ("\limit can be changed using -gnateinn switch", N); + raise Unrecoverable_Error; + end if; + + -- Indicate that the enclosing scopes contain an instantiation, + -- and that cleanup actions should be delayed until after the + -- instance body is expanded. + + Check_Forward_Instantiation (Gen_Decl); + if Nkind (N) = N_Package_Instantiation then + declare + Enclosing_Master : Entity_Id; + + begin + -- Loop to search enclosing masters + + Enclosing_Master := Current_Scope; + Scope_Loop : while Enclosing_Master /= Standard_Standard loop + if Ekind (Enclosing_Master) = E_Package then + if Is_Compilation_Unit (Enclosing_Master) then + if In_Package_Body (Enclosing_Master) then + Delay_Descriptors + (Body_Entity (Enclosing_Master)); + else + Delay_Descriptors + (Enclosing_Master); + end if; + + exit Scope_Loop; + + else + Enclosing_Master := Scope (Enclosing_Master); + end if; + + elsif Is_Generic_Unit (Enclosing_Master) + or else Ekind (Enclosing_Master) = E_Void + then + -- Cleanup actions will eventually be performed on the + -- enclosing subprogram or package instance, if any. + -- Enclosing scope is void in the formal part of a + -- generic subprogram. + + exit Scope_Loop; + + else + if Ekind (Enclosing_Master) = E_Entry + and then + Ekind (Scope (Enclosing_Master)) = E_Protected_Type + then + if not Expander_Active then + exit Scope_Loop; + else + Enclosing_Master := + Protected_Body_Subprogram (Enclosing_Master); + end if; + end if; + + Set_Delay_Cleanups (Enclosing_Master); + + while Ekind (Enclosing_Master) = E_Block loop + Enclosing_Master := Scope (Enclosing_Master); + end loop; + + if Is_Subprogram (Enclosing_Master) then + Delay_Descriptors (Enclosing_Master); + + elsif Is_Task_Type (Enclosing_Master) then + declare + TBP : constant Node_Id := + Get_Task_Body_Procedure + (Enclosing_Master); + begin + if Present (TBP) then + Delay_Descriptors (TBP); + Set_Delay_Cleanups (TBP); + end if; + end; + end if; + + exit Scope_Loop; + end if; + end loop Scope_Loop; + end; + + -- Make entry in table + + Pending_Instantiations.Append + ((Inst_Node => N, + Act_Decl => Act_Decl, + Expander_Status => Expander_Active, + Current_Sem_Unit => Current_Sem_Unit, + Scope_Suppress => Scope_Suppress, + Local_Suppress_Stack_Top => Local_Suppress_Stack_Top, + Version => Ada_Version, + Version_Pragma => Ada_Version_Pragma, + Warnings => Save_Warnings, + SPARK_Mode => SPARK_Mode, + SPARK_Mode_Pragma => SPARK_Mode_Pragma)); + end if; + end if; + + Set_Categorization_From_Pragmas (Act_Decl); + + if Parent_Installed then + Hide_Current_Scope; + end if; + + Set_Instance_Spec (N, Act_Decl); + + -- If not a compilation unit, insert the package declaration before + -- the original instantiation node. + + if Nkind (Parent (N)) /= N_Compilation_Unit then + Mark_Rewrite_Insertion (Act_Decl); + Insert_Before (N, Act_Decl); + Analyze (Act_Decl); + + -- For an instantiation that is a compilation unit, place + -- declaration on current node so context is complete for analysis + -- (including nested instantiations). If this is the main unit, + -- the declaration eventually replaces the instantiation node. + -- If the instance body is created later, it replaces the + -- instance node, and the declaration is attached to it + -- (see Build_Instance_Compilation_Unit_Nodes). + + else + if Cunit_Entity (Current_Sem_Unit) = Defining_Entity (N) then + + -- The entity for the current unit is the newly created one, + -- and all semantic information is attached to it. + + Set_Cunit_Entity (Current_Sem_Unit, Act_Decl_Id); + + -- If this is the main unit, replace the main entity as well + + if Current_Sem_Unit = Main_Unit then + Main_Unit_Entity := Act_Decl_Id; + end if; + end if; + + Set_Unit (Parent (N), Act_Decl); + Set_Parent_Spec (Act_Decl, Parent_Spec (N)); + Set_Package_Instantiation (Act_Decl_Id, N); + + -- Process aspect specifications of the instance node, if any, to + -- take into account categorization pragmas before analyzing the + -- instance. + + if Has_Aspects (N) then + Analyze_Aspect_Specifications (N, Act_Decl_Id); + end if; + + Analyze (Act_Decl); + Set_Unit (Parent (N), N); + Set_Body_Required (Parent (N), False); + + -- We never need elaboration checks on instantiations, since by + -- definition, the body instantiation is elaborated at the same + -- time as the spec instantiation. + + Set_Suppress_Elaboration_Warnings (Act_Decl_Id); + Set_Kill_Elaboration_Checks (Act_Decl_Id); + end if; + + Check_Elab_Instantiation (N); + + if ABE_Is_Certain (N) and then Needs_Body then + Pending_Instantiations.Decrement_Last; + end if; + + Check_Hidden_Child_Unit (N, Gen_Unit, Act_Decl_Id); + + Set_First_Private_Entity (Defining_Unit_Name (Unit_Renaming), + First_Private_Entity (Act_Decl_Id)); + + -- If the instantiation will receive a body, the unit will be + -- transformed into a package body, and receive its own elaboration + -- entity. Otherwise, the nature of the unit is now a package + -- declaration. + + if Nkind (Parent (N)) = N_Compilation_Unit + and then not Needs_Body + then + Rewrite (N, Act_Decl); + end if; + + if Present (Corresponding_Body (Gen_Decl)) + or else Unit_Requires_Body (Gen_Unit) + then + Set_Has_Completion (Act_Decl_Id); + end if; + + Check_Formal_Packages (Act_Decl_Id); + + Restore_Hidden_Primitives (Vis_Prims_List); + Restore_Private_Views (Act_Decl_Id); + + Inherit_Context (Gen_Decl, N); + + if Parent_Installed then + Remove_Parent; + end if; + + Restore_Env; + Env_Installed := False; + end if; + + Validate_Categorization_Dependency (N, Act_Decl_Id); + + -- There used to be a check here to prevent instantiations in local + -- contexts if the No_Local_Allocators restriction was active. This + -- check was removed by a binding interpretation in AI-95-00130/07, + -- but we retain the code for documentation purposes. + + -- if Ekind (Act_Decl_Id) /= E_Void + -- and then not Is_Library_Level_Entity (Act_Decl_Id) + -- then + -- Check_Restriction (No_Local_Allocators, N); + -- end if; + + if Inline_Now then + Inline_Instance_Body (N, Gen_Unit, Act_Decl); + end if; + + -- The following is a tree patch for ASIS: ASIS needs separate nodes to + -- be used as defining identifiers for a formal package and for the + -- corresponding expanded package. + + if Nkind (N) = N_Formal_Package_Declaration then + Act_Decl_Id := New_Copy (Defining_Entity (N)); + Set_Comes_From_Source (Act_Decl_Id, True); + Set_Is_Generic_Instance (Act_Decl_Id, False); + Set_Defining_Identifier (N, Act_Decl_Id); + end if; + + Style_Check := Save_Style_Check; + + -- Check that if N is an instantiation of System.Dim_Float_IO or + -- System.Dim_Integer_IO, the formal type has a dimension system. + + if Nkind (N) = N_Package_Instantiation + and then Is_Dim_IO_Package_Instantiation (N) + then + declare + Assoc : constant Node_Id := First (Generic_Associations (N)); + begin + if not Has_Dimension_System + (Etype (Explicit_Generic_Actual_Parameter (Assoc))) + then + Error_Msg_N ("type with a dimension system expected", Assoc); + end if; + end; + end if; + + <<Leave>> + if Has_Aspects (N) and then Nkind (Parent (N)) /= N_Compilation_Unit then + Analyze_Aspect_Specifications (N, Act_Decl_Id); + end if; + + exception + when Instantiation_Error => + if Parent_Installed then + Remove_Parent; + end if; + + if Env_Installed then + Restore_Env; + end if; + + Style_Check := Save_Style_Check; + end Analyze_Package_Instantiation; + + -------------------------- + -- Inline_Instance_Body -- + -------------------------- + + procedure Inline_Instance_Body + (N : Node_Id; + Gen_Unit : Entity_Id; + Act_Decl : Node_Id) + is + Vis : Boolean; + Gen_Comp : constant Entity_Id := + Cunit_Entity (Get_Source_Unit (Gen_Unit)); + Curr_Comp : constant Node_Id := Cunit (Current_Sem_Unit); + Curr_Scope : Entity_Id := Empty; + Curr_Unit : constant Entity_Id := Cunit_Entity (Current_Sem_Unit); + Removed : Boolean := False; + Num_Scopes : Int := 0; + + Scope_Stack_Depth : constant Int := + Scope_Stack.Last - Scope_Stack.First + 1; + + Use_Clauses : array (1 .. Scope_Stack_Depth) of Node_Id; + Instances : array (1 .. Scope_Stack_Depth) of Entity_Id; + Inner_Scopes : array (1 .. Scope_Stack_Depth) of Entity_Id; + List : Elist_Id; + Num_Inner : Int := 0; + N_Instances : Int := 0; + S : Entity_Id; + + begin + -- Case of generic unit defined in another unit. We must remove the + -- complete context of the current unit to install that of the generic. + + if Gen_Comp /= Cunit_Entity (Current_Sem_Unit) then + + -- Add some comments for the following two loops ??? + + S := Current_Scope; + while Present (S) and then S /= Standard_Standard loop + loop + Num_Scopes := Num_Scopes + 1; + + Use_Clauses (Num_Scopes) := + (Scope_Stack.Table + (Scope_Stack.Last - Num_Scopes + 1). + First_Use_Clause); + End_Use_Clauses (Use_Clauses (Num_Scopes)); + + exit when Scope_Stack.Last - Num_Scopes + 1 = Scope_Stack.First + or else Scope_Stack.Table + (Scope_Stack.Last - Num_Scopes).Entity + = Scope (S); + end loop; + + exit when Is_Generic_Instance (S) + and then (In_Package_Body (S) + or else Ekind (S) = E_Procedure + or else Ekind (S) = E_Function); + S := Scope (S); + end loop; + + Vis := Is_Immediately_Visible (Gen_Comp); + + -- Find and save all enclosing instances + + S := Current_Scope; + + while Present (S) + and then S /= Standard_Standard + loop + if Is_Generic_Instance (S) then + N_Instances := N_Instances + 1; + Instances (N_Instances) := S; + + exit when In_Package_Body (S); + end if; + + S := Scope (S); + end loop; + + -- Remove context of current compilation unit, unless we are within a + -- nested package instantiation, in which case the context has been + -- removed previously. + + -- If current scope is the body of a child unit, remove context of + -- spec as well. If an enclosing scope is an instance body, the + -- context has already been removed, but the entities in the body + -- must be made invisible as well. + + S := Current_Scope; + + while Present (S) + and then S /= Standard_Standard + loop + if Is_Generic_Instance (S) + and then (In_Package_Body (S) + or else Ekind (S) = E_Procedure + or else Ekind (S) = E_Function) + then + -- We still have to remove the entities of the enclosing + -- instance from direct visibility. + + declare + E : Entity_Id; + begin + E := First_Entity (S); + while Present (E) loop + Set_Is_Immediately_Visible (E, False); + Next_Entity (E); + end loop; + end; + + exit; + end if; + + if S = Curr_Unit + or else (Ekind (Curr_Unit) = E_Package_Body + and then S = Spec_Entity (Curr_Unit)) + or else (Ekind (Curr_Unit) = E_Subprogram_Body + and then S = + Corresponding_Spec + (Unit_Declaration_Node (Curr_Unit))) + then + Removed := True; + + -- Remove entities in current scopes from visibility, so that + -- instance body is compiled in a clean environment. + + List := Save_Scope_Stack (Handle_Use => False); + + if Is_Child_Unit (S) then + + -- Remove child unit from stack, as well as inner scopes. + -- Removing the context of a child unit removes parent units + -- as well. + + while Current_Scope /= S loop + Num_Inner := Num_Inner + 1; + Inner_Scopes (Num_Inner) := Current_Scope; + Pop_Scope; + end loop; + + Pop_Scope; + Remove_Context (Curr_Comp); + Curr_Scope := S; + + else + Remove_Context (Curr_Comp); + end if; + + if Ekind (Curr_Unit) = E_Package_Body then + Remove_Context (Library_Unit (Curr_Comp)); + end if; + end if; + + S := Scope (S); + end loop; + pragma Assert (Num_Inner < Num_Scopes); + + Push_Scope (Standard_Standard); + Scope_Stack.Table (Scope_Stack.Last).Is_Active_Stack_Base := True; + Instantiate_Package_Body + (Body_Info => + ((Inst_Node => N, + Act_Decl => Act_Decl, + Expander_Status => Expander_Active, + Current_Sem_Unit => Current_Sem_Unit, + Scope_Suppress => Scope_Suppress, + Local_Suppress_Stack_Top => Local_Suppress_Stack_Top, + Version => Ada_Version, + Version_Pragma => Ada_Version_Pragma, + Warnings => Save_Warnings, + SPARK_Mode => SPARK_Mode, + SPARK_Mode_Pragma => SPARK_Mode_Pragma)), + Inlined_Body => True); + + Pop_Scope; + + -- Restore context + + Set_Is_Immediately_Visible (Gen_Comp, Vis); + + -- Reset Generic_Instance flag so that use clauses can be installed + -- in the proper order. (See Use_One_Package for effect of enclosing + -- instances on processing of use clauses). + + for J in 1 .. N_Instances loop + Set_Is_Generic_Instance (Instances (J), False); + end loop; + + if Removed then + Install_Context (Curr_Comp); + + if Present (Curr_Scope) + and then Is_Child_Unit (Curr_Scope) + then + Push_Scope (Curr_Scope); + Set_Is_Immediately_Visible (Curr_Scope); + + -- Finally, restore inner scopes as well + + for J in reverse 1 .. Num_Inner loop + Push_Scope (Inner_Scopes (J)); + end loop; + end if; + + Restore_Scope_Stack (List, Handle_Use => False); + + if Present (Curr_Scope) + and then + (In_Private_Part (Curr_Scope) + or else In_Package_Body (Curr_Scope)) + then + -- Install private declaration of ancestor units, which are + -- currently available. Restore_Scope_Stack and Install_Context + -- only install the visible part of parents. + + declare + Par : Entity_Id; + begin + Par := Scope (Curr_Scope); + while (Present (Par)) + and then Par /= Standard_Standard + loop + Install_Private_Declarations (Par); + Par := Scope (Par); + end loop; + end; + end if; + end if; + + -- Restore use clauses. For a child unit, use clauses in the parents + -- are restored when installing the context, so only those in inner + -- scopes (and those local to the child unit itself) need to be + -- installed explicitly. + + if Is_Child_Unit (Curr_Unit) + and then Removed + then + for J in reverse 1 .. Num_Inner + 1 loop + Scope_Stack.Table (Scope_Stack.Last - J + 1).First_Use_Clause := + Use_Clauses (J); + Install_Use_Clauses (Use_Clauses (J)); + end loop; + + else + for J in reverse 1 .. Num_Scopes loop + Scope_Stack.Table (Scope_Stack.Last - J + 1).First_Use_Clause := + Use_Clauses (J); + Install_Use_Clauses (Use_Clauses (J)); + end loop; + end if; + + -- Restore status of instances. If one of them is a body, make its + -- local entities visible again. + + declare + E : Entity_Id; + Inst : Entity_Id; + + begin + for J in 1 .. N_Instances loop + Inst := Instances (J); + Set_Is_Generic_Instance (Inst, True); + + if In_Package_Body (Inst) + or else Ekind (S) = E_Procedure + or else Ekind (S) = E_Function + then + E := First_Entity (Instances (J)); + while Present (E) loop + Set_Is_Immediately_Visible (E); + Next_Entity (E); + end loop; + end if; + end loop; + end; + + -- If generic unit is in current unit, current context is correct + + else + Instantiate_Package_Body + (Body_Info => + ((Inst_Node => N, + Act_Decl => Act_Decl, + Expander_Status => Expander_Active, + Current_Sem_Unit => Current_Sem_Unit, + Scope_Suppress => Scope_Suppress, + Local_Suppress_Stack_Top => Local_Suppress_Stack_Top, + Version => Ada_Version, + Version_Pragma => Ada_Version_Pragma, + Warnings => Save_Warnings, + SPARK_Mode => SPARK_Mode, + SPARK_Mode_Pragma => SPARK_Mode_Pragma)), + Inlined_Body => True); + end if; + end Inline_Instance_Body; + + ------------------------------------- + -- Analyze_Procedure_Instantiation -- + ------------------------------------- + + procedure Analyze_Procedure_Instantiation (N : Node_Id) is + begin + Analyze_Subprogram_Instantiation (N, E_Procedure); + end Analyze_Procedure_Instantiation; + + ----------------------------------- + -- Need_Subprogram_Instance_Body -- + ----------------------------------- + + function Need_Subprogram_Instance_Body + (N : Node_Id; + Subp : Entity_Id) return Boolean + is + begin + -- Must be inlined (or inlined renaming) + + if (Is_In_Main_Unit (N) + or else Is_Inlined (Subp) + or else Is_Inlined (Alias (Subp))) + + -- Must be generating code or analyzing code in ASIS/GNATprove mode + + and then (Operating_Mode = Generate_Code + or else (Operating_Mode = Check_Semantics + and then (ASIS_Mode or GNATprove_Mode))) + + -- The body is needed when generating code (full expansion), in ASIS + -- mode for other tools, and in GNATprove mode (special expansion) for + -- formal verification of the body itself. + + and then (Expander_Active or ASIS_Mode or GNATprove_Mode) + + -- No point in inlining if ABE is inevitable + + and then not ABE_Is_Certain (N) + + -- Or if subprogram is eliminated + + and then not Is_Eliminated (Subp) + then + Pending_Instantiations.Append + ((Inst_Node => N, + Act_Decl => Unit_Declaration_Node (Subp), + Expander_Status => Expander_Active, + Current_Sem_Unit => Current_Sem_Unit, + Scope_Suppress => Scope_Suppress, + Local_Suppress_Stack_Top => Local_Suppress_Stack_Top, + Version => Ada_Version, + Version_Pragma => Ada_Version_Pragma, + Warnings => Save_Warnings, + SPARK_Mode => SPARK_Mode, + SPARK_Mode_Pragma => SPARK_Mode_Pragma)); + return True; + + -- Here if not inlined, or we ignore the inlining + + else + return False; + end if; + end Need_Subprogram_Instance_Body; + + -------------------------------------- + -- Analyze_Subprogram_Instantiation -- + -------------------------------------- + + procedure Analyze_Subprogram_Instantiation + (N : Node_Id; + K : Entity_Kind) + is + Loc : constant Source_Ptr := Sloc (N); + Gen_Id : constant Node_Id := Name (N); + + Anon_Id : constant Entity_Id := + Make_Defining_Identifier (Sloc (Defining_Entity (N)), + Chars => New_External_Name + (Chars (Defining_Entity (N)), 'R')); + + Act_Decl_Id : Entity_Id; + Act_Decl : Node_Id; + Act_Spec : Node_Id; + Act_Tree : Node_Id; + + Env_Installed : Boolean := False; + Gen_Unit : Entity_Id; + Gen_Decl : Node_Id; + Pack_Id : Entity_Id; + Parent_Installed : Boolean := False; + Renaming_List : List_Id; + + procedure Analyze_Instance_And_Renamings; + -- The instance must be analyzed in a context that includes the mappings + -- of generic parameters into actuals. We create a package declaration + -- for this purpose, and a subprogram with an internal name within the + -- package. The subprogram instance is simply an alias for the internal + -- subprogram, declared in the current scope. + + ------------------------------------ + -- Analyze_Instance_And_Renamings -- + ------------------------------------ + + procedure Analyze_Instance_And_Renamings is + Def_Ent : constant Entity_Id := Defining_Entity (N); + Pack_Decl : Node_Id; + + begin + if Nkind (Parent (N)) = N_Compilation_Unit then + + -- For the case of a compilation unit, the container package has + -- the same name as the instantiation, to insure that the binder + -- calls the elaboration procedure with the right name. Copy the + -- entity of the instance, which may have compilation level flags + -- (e.g. Is_Child_Unit) set. + + Pack_Id := New_Copy (Def_Ent); + + else + -- Otherwise we use the name of the instantiation concatenated + -- with its source position to ensure uniqueness if there are + -- several instantiations with the same name. + + Pack_Id := + Make_Defining_Identifier (Loc, + Chars => New_External_Name + (Related_Id => Chars (Def_Ent), + Suffix => "GP", + Suffix_Index => Source_Offset (Sloc (Def_Ent)))); + end if; + + Pack_Decl := Make_Package_Declaration (Loc, + Specification => Make_Package_Specification (Loc, + Defining_Unit_Name => Pack_Id, + Visible_Declarations => Renaming_List, + End_Label => Empty)); + + Set_Instance_Spec (N, Pack_Decl); + Set_Is_Generic_Instance (Pack_Id); + Set_Debug_Info_Needed (Pack_Id); + + -- Case of not a compilation unit + + if Nkind (Parent (N)) /= N_Compilation_Unit then + Mark_Rewrite_Insertion (Pack_Decl); + Insert_Before (N, Pack_Decl); + Set_Has_Completion (Pack_Id); + + -- Case of an instantiation that is a compilation unit + + -- Place declaration on current node so context is complete for + -- analysis (including nested instantiations), and for use in a + -- context_clause (see Analyze_With_Clause). + + else + Set_Unit (Parent (N), Pack_Decl); + Set_Parent_Spec (Pack_Decl, Parent_Spec (N)); + end if; + + Analyze (Pack_Decl); + Check_Formal_Packages (Pack_Id); + Set_Is_Generic_Instance (Pack_Id, False); + + -- Why do we clear Is_Generic_Instance??? We set it 20 lines + -- above??? + + -- Body of the enclosing package is supplied when instantiating the + -- subprogram body, after semantic analysis is completed. + + if Nkind (Parent (N)) = N_Compilation_Unit then + + -- Remove package itself from visibility, so it does not + -- conflict with subprogram. + + Set_Name_Entity_Id (Chars (Pack_Id), Homonym (Pack_Id)); + + -- Set name and scope of internal subprogram so that the proper + -- external name will be generated. The proper scope is the scope + -- of the wrapper package. We need to generate debugging info for + -- the internal subprogram, so set flag accordingly. + + Set_Chars (Anon_Id, Chars (Defining_Entity (N))); + Set_Scope (Anon_Id, Scope (Pack_Id)); + + -- Mark wrapper package as referenced, to avoid spurious warnings + -- if the instantiation appears in various with_ clauses of + -- subunits of the main unit. + + Set_Referenced (Pack_Id); + end if; + + Set_Is_Generic_Instance (Anon_Id); + Set_Debug_Info_Needed (Anon_Id); + Act_Decl_Id := New_Copy (Anon_Id); + + Set_Parent (Act_Decl_Id, Parent (Anon_Id)); + Set_Chars (Act_Decl_Id, Chars (Defining_Entity (N))); + Set_Sloc (Act_Decl_Id, Sloc (Defining_Entity (N))); + Set_Comes_From_Source (Act_Decl_Id, True); + + -- The signature may involve types that are not frozen yet, but the + -- subprogram will be frozen at the point the wrapper package is + -- frozen, so it does not need its own freeze node. In fact, if one + -- is created, it might conflict with the freezing actions from the + -- wrapper package. + + Set_Has_Delayed_Freeze (Anon_Id, False); + + -- If the instance is a child unit, mark the Id accordingly. Mark + -- the anonymous entity as well, which is the real subprogram and + -- which is used when the instance appears in a context clause. + -- Similarly, propagate the Is_Eliminated flag to handle properly + -- nested eliminated subprograms. + + Set_Is_Child_Unit (Act_Decl_Id, Is_Child_Unit (Defining_Entity (N))); + Set_Is_Child_Unit (Anon_Id, Is_Child_Unit (Defining_Entity (N))); + New_Overloaded_Entity (Act_Decl_Id); + Check_Eliminated (Act_Decl_Id); + Set_Is_Eliminated (Anon_Id, Is_Eliminated (Act_Decl_Id)); + + -- In compilation unit case, kill elaboration checks on the + -- instantiation, since they are never needed -- the body is + -- instantiated at the same point as the spec. + + if Nkind (Parent (N)) = N_Compilation_Unit then + Set_Suppress_Elaboration_Warnings (Act_Decl_Id); + Set_Kill_Elaboration_Checks (Act_Decl_Id); + Set_Is_Compilation_Unit (Anon_Id); + + Set_Cunit_Entity (Current_Sem_Unit, Pack_Id); + end if; + + -- The instance is not a freezing point for the new subprogram + + Set_Is_Frozen (Act_Decl_Id, False); + + if Nkind (Defining_Entity (N)) = N_Defining_Operator_Symbol then + Valid_Operator_Definition (Act_Decl_Id); + end if; + + Set_Alias (Act_Decl_Id, Anon_Id); + Set_Parent (Act_Decl_Id, Parent (Anon_Id)); + Set_Has_Completion (Act_Decl_Id); + Set_Related_Instance (Pack_Id, Act_Decl_Id); + + if Nkind (Parent (N)) = N_Compilation_Unit then + Set_Body_Required (Parent (N), False); + end if; + end Analyze_Instance_And_Renamings; + + -- Local variables + + Vis_Prims_List : Elist_Id := No_Elist; + -- List of primitives made temporarily visible in the instantiation + -- to match the visibility of the formal type + + -- Start of processing for Analyze_Subprogram_Instantiation + + begin + Check_SPARK_Restriction ("generic is not allowed", N); + + -- Very first thing: apply the special kludge for Text_IO processing + -- in case we are instantiating one of the children of [Wide_]Text_IO. + -- Of course such an instantiation is bogus (these are packages, not + -- subprograms), but we get a better error message if we do this. + + Text_IO_Kludge (Gen_Id); + + -- Make node global for error reporting + + Instantiation_Node := N; + + -- For package instantiations we turn off style checks, because they + -- will have been emitted in the generic. For subprogram instantiations + -- we want to apply at least the check on overriding indicators so we + -- do not modify the style check status. + + -- The renaming declarations for the actuals do not come from source and + -- will not generate spurious warnings. + + Preanalyze_Actuals (N); + + Init_Env; + Env_Installed := True; + Check_Generic_Child_Unit (Gen_Id, Parent_Installed); + Gen_Unit := Entity (Gen_Id); + + Generate_Reference (Gen_Unit, Gen_Id); + + if Nkind (Gen_Id) = N_Identifier + and then Chars (Gen_Unit) = Chars (Defining_Entity (N)) + then + Error_Msg_NE + ("& is hidden within declaration of instance", Gen_Id, Gen_Unit); + end if; + + if Etype (Gen_Unit) = Any_Type then + Restore_Env; + return; + end if; + + -- Verify that it is a generic subprogram of the right kind, and that + -- it does not lead to a circular instantiation. + + if K = E_Procedure and then Ekind (Gen_Unit) /= E_Generic_Procedure then + Error_Msg_NE + ("& is not the name of a generic procedure", Gen_Id, Gen_Unit); + + elsif K = E_Function and then Ekind (Gen_Unit) /= E_Generic_Function then + Error_Msg_NE + ("& is not the name of a generic function", Gen_Id, Gen_Unit); + + elsif In_Open_Scopes (Gen_Unit) then + Error_Msg_NE ("instantiation of & within itself", N, Gen_Unit); + + else + Set_Entity (Gen_Id, Gen_Unit); + Set_Is_Instantiated (Gen_Unit); + + if In_Extended_Main_Source_Unit (N) then + Generate_Reference (Gen_Unit, N); + end if; + + -- If renaming, get original unit + + if Present (Renamed_Object (Gen_Unit)) + and then (Ekind (Renamed_Object (Gen_Unit)) = E_Generic_Procedure + or else + Ekind (Renamed_Object (Gen_Unit)) = E_Generic_Function) + then + Gen_Unit := Renamed_Object (Gen_Unit); + Set_Is_Instantiated (Gen_Unit); + Generate_Reference (Gen_Unit, N); + end if; + + if Contains_Instance_Of (Gen_Unit, Current_Scope, Gen_Id) then + Error_Msg_Node_2 := Current_Scope; + Error_Msg_NE + ("circular Instantiation: & instantiated in &!", N, Gen_Unit); + Circularity_Detected := True; + Restore_Hidden_Primitives (Vis_Prims_List); + goto Leave; + end if; + + Gen_Decl := Unit_Declaration_Node (Gen_Unit); + + -- Initialize renamings map, for error checking + + Generic_Renamings.Set_Last (0); + Generic_Renamings_HTable.Reset; + + Create_Instantiation_Source (N, Gen_Unit, False, S_Adjustment); + + -- Copy original generic tree, to produce text for instantiation + + Act_Tree := + Copy_Generic_Node + (Original_Node (Gen_Decl), Empty, Instantiating => True); + + -- Inherit overriding indicator from instance node + + Act_Spec := Specification (Act_Tree); + Set_Must_Override (Act_Spec, Must_Override (N)); + Set_Must_Not_Override (Act_Spec, Must_Not_Override (N)); + + Renaming_List := + Analyze_Associations + (I_Node => N, + Formals => Generic_Formal_Declarations (Act_Tree), + F_Copy => Generic_Formal_Declarations (Gen_Decl)); + + Vis_Prims_List := Check_Hidden_Primitives (Renaming_List); + + -- The subprogram itself cannot contain a nested instance, so the + -- current parent is left empty. + + Set_Instance_Env (Gen_Unit, Empty); + + -- Build the subprogram declaration, which does not appear in the + -- generic template, and give it a sloc consistent with that of the + -- template. + + Set_Defining_Unit_Name (Act_Spec, Anon_Id); + Set_Generic_Parent (Act_Spec, Gen_Unit); + Act_Decl := + Make_Subprogram_Declaration (Sloc (Act_Spec), + Specification => Act_Spec); + + -- The aspects have been copied previously, but they have to be + -- linked explicitly to the new subprogram declaration. Explicit + -- pre/postconditions on the instance are analyzed below, in a + -- separate step. + + Move_Aspects (Act_Tree, To => Act_Decl); + Set_Categorization_From_Pragmas (Act_Decl); + + if Parent_Installed then + Hide_Current_Scope; + end if; + + Append (Act_Decl, Renaming_List); + Analyze_Instance_And_Renamings; + + -- If the generic is marked Import (Intrinsic), then so is the + -- instance. This indicates that there is no body to instantiate. If + -- generic is marked inline, so it the instance, and the anonymous + -- subprogram it renames. If inlined, or else if inlining is enabled + -- for the compilation, we generate the instance body even if it is + -- not within the main unit. + + if Is_Intrinsic_Subprogram (Gen_Unit) then + Set_Is_Intrinsic_Subprogram (Anon_Id); + Set_Is_Intrinsic_Subprogram (Act_Decl_Id); + + if Chars (Gen_Unit) = Name_Unchecked_Conversion then + Validate_Unchecked_Conversion (N, Act_Decl_Id); + end if; + end if; + + -- Inherit convention from generic unit. Intrinsic convention, as for + -- an instance of unchecked conversion, is not inherited because an + -- explicit Ada instance has been created. + + if Has_Convention_Pragma (Gen_Unit) + and then Convention (Gen_Unit) /= Convention_Intrinsic + then + Set_Convention (Act_Decl_Id, Convention (Gen_Unit)); + Set_Is_Exported (Act_Decl_Id, Is_Exported (Gen_Unit)); + end if; + + Generate_Definition (Act_Decl_Id); + -- Set_Contract (Anon_Id, Make_Contract (Sloc (Anon_Id))); + -- ??? needed? + Set_Contract (Act_Decl_Id, Make_Contract (Sloc (Act_Decl_Id))); + + -- Inherit all inlining-related flags which apply to the generic in + -- the subprogram and its declaration. + + Set_Is_Inlined (Act_Decl_Id, Is_Inlined (Gen_Unit)); + Set_Is_Inlined (Anon_Id, Is_Inlined (Gen_Unit)); + + Set_Has_Pragma_Inline (Act_Decl_Id, Has_Pragma_Inline (Gen_Unit)); + Set_Has_Pragma_Inline (Anon_Id, Has_Pragma_Inline (Gen_Unit)); + + Set_Has_Pragma_Inline_Always + (Act_Decl_Id, Has_Pragma_Inline_Always (Gen_Unit)); + Set_Has_Pragma_Inline_Always + (Anon_Id, Has_Pragma_Inline_Always (Gen_Unit)); + + if not Is_Intrinsic_Subprogram (Gen_Unit) then + Check_Elab_Instantiation (N); + end if; + + if Is_Dispatching_Operation (Act_Decl_Id) + and then Ada_Version >= Ada_2005 + then + declare + Formal : Entity_Id; + + begin + Formal := First_Formal (Act_Decl_Id); + while Present (Formal) loop + if Ekind (Etype (Formal)) = E_Anonymous_Access_Type + and then Is_Controlling_Formal (Formal) + and then not Can_Never_Be_Null (Formal) + then + Error_Msg_NE ("access parameter& is controlling,", + N, Formal); + Error_Msg_NE + ("\corresponding parameter of & must be" + & " explicitly null-excluding", N, Gen_Id); + end if; + + Next_Formal (Formal); + end loop; + end; + end if; + + Check_Hidden_Child_Unit (N, Gen_Unit, Act_Decl_Id); + + Validate_Categorization_Dependency (N, Act_Decl_Id); + + if not Is_Intrinsic_Subprogram (Act_Decl_Id) then + Inherit_Context (Gen_Decl, N); + + Restore_Private_Views (Pack_Id, False); + + -- If the context requires a full instantiation, mark node for + -- subsequent construction of the body. + + if Need_Subprogram_Instance_Body (N, Act_Decl_Id) then + Check_Forward_Instantiation (Gen_Decl); + + -- The wrapper package is always delayed, because it does not + -- constitute a freeze point, but to insure that the freeze + -- node is placed properly, it is created directly when + -- instantiating the body (otherwise the freeze node might + -- appear to early for nested instantiations). + + elsif Nkind (Parent (N)) = N_Compilation_Unit then + + -- For ASIS purposes, indicate that the wrapper package has + -- replaced the instantiation node. + + Rewrite (N, Unit (Parent (N))); + Set_Unit (Parent (N), N); + end if; + + elsif Nkind (Parent (N)) = N_Compilation_Unit then + + -- Replace instance node for library-level instantiations of + -- intrinsic subprograms, for ASIS use. + + Rewrite (N, Unit (Parent (N))); + Set_Unit (Parent (N), N); + end if; + + if Parent_Installed then + Remove_Parent; + end if; + + Restore_Hidden_Primitives (Vis_Prims_List); + Restore_Env; + Env_Installed := False; + Generic_Renamings.Set_Last (0); + Generic_Renamings_HTable.Reset; + end if; + + <<Leave>> + if Has_Aspects (N) then + Analyze_Aspect_Specifications (N, Act_Decl_Id); + end if; + + exception + when Instantiation_Error => + if Parent_Installed then + Remove_Parent; + end if; + + if Env_Installed then + Restore_Env; + end if; + end Analyze_Subprogram_Instantiation; + + ------------------------- + -- Get_Associated_Node -- + ------------------------- + + function Get_Associated_Node (N : Node_Id) return Node_Id is + Assoc : Node_Id; + + begin + Assoc := Associated_Node (N); + + if Nkind (Assoc) /= Nkind (N) then + return Assoc; + + elsif Nkind_In (Assoc, N_Aggregate, N_Extension_Aggregate) then + return Assoc; + + else + -- If the node is part of an inner generic, it may itself have been + -- remapped into a further generic copy. Associated_Node is otherwise + -- used for the entity of the node, and will be of a different node + -- kind, or else N has been rewritten as a literal or function call. + + while Present (Associated_Node (Assoc)) + and then Nkind (Associated_Node (Assoc)) = Nkind (Assoc) + loop + Assoc := Associated_Node (Assoc); + end loop; + + -- Follow and additional link in case the final node was rewritten. + -- This can only happen with nested generic units. + + if (Nkind (Assoc) = N_Identifier or else Nkind (Assoc) in N_Op) + and then Present (Associated_Node (Assoc)) + and then (Nkind_In (Associated_Node (Assoc), N_Function_Call, + N_Explicit_Dereference, + N_Integer_Literal, + N_Real_Literal, + N_String_Literal)) + then + Assoc := Associated_Node (Assoc); + end if; + + -- An additional special case: an unconstrained type in an object + -- declaration may have been rewritten as a local subtype constrained + -- by the expression in the declaration. We need to recover the + -- original entity which may be global. + + if Present (Original_Node (Assoc)) + and then Nkind (Parent (N)) = N_Object_Declaration + then + Assoc := Original_Node (Assoc); + end if; + + return Assoc; + end if; + end Get_Associated_Node; + + ------------------------------------------- + -- Build_Instance_Compilation_Unit_Nodes -- + ------------------------------------------- + + procedure Build_Instance_Compilation_Unit_Nodes + (N : Node_Id; + Act_Body : Node_Id; + Act_Decl : Node_Id) + is + Decl_Cunit : Node_Id; + Body_Cunit : Node_Id; + Citem : Node_Id; + New_Main : constant Entity_Id := Defining_Entity (Act_Decl); + Old_Main : constant Entity_Id := Cunit_Entity (Main_Unit); + + begin + -- A new compilation unit node is built for the instance declaration + + Decl_Cunit := + Make_Compilation_Unit (Sloc (N), + Context_Items => Empty_List, + Unit => Act_Decl, + Aux_Decls_Node => Make_Compilation_Unit_Aux (Sloc (N))); + + Set_Parent_Spec (Act_Decl, Parent_Spec (N)); + + -- The new compilation unit is linked to its body, but both share the + -- same file, so we do not set Body_Required on the new unit so as not + -- to create a spurious dependency on a non-existent body in the ali. + -- This simplifies CodePeer unit traversal. + + -- We use the original instantiation compilation unit as the resulting + -- compilation unit of the instance, since this is the main unit. + + Rewrite (N, Act_Body); + + -- Propagate the aspect specifications from the package body template to + -- the instantiated version of the package body. + + if Has_Aspects (Act_Body) then + Set_Aspect_Specifications + (N, New_Copy_List_Tree (Aspect_Specifications (Act_Body))); + end if; + + Body_Cunit := Parent (N); + + -- The two compilation unit nodes are linked by the Library_Unit field + + Set_Library_Unit (Decl_Cunit, Body_Cunit); + Set_Library_Unit (Body_Cunit, Decl_Cunit); + + -- Preserve the private nature of the package if needed + + Set_Private_Present (Decl_Cunit, Private_Present (Body_Cunit)); + + -- If the instance is not the main unit, its context, categorization + -- and elaboration entity are not relevant to the compilation. + + if Body_Cunit /= Cunit (Main_Unit) then + Make_Instance_Unit (Body_Cunit, In_Main => False); + return; + end if; + + -- The context clause items on the instantiation, which are now attached + -- to the body compilation unit (since the body overwrote the original + -- instantiation node), semantically belong on the spec, so copy them + -- there. It's harmless to leave them on the body as well. In fact one + -- could argue that they belong in both places. + + Citem := First (Context_Items (Body_Cunit)); + while Present (Citem) loop + Append (New_Copy (Citem), Context_Items (Decl_Cunit)); + Next (Citem); + end loop; + + -- Propagate categorization flags on packages, so that they appear in + -- the ali file for the spec of the unit. + + if Ekind (New_Main) = E_Package then + Set_Is_Pure (Old_Main, Is_Pure (New_Main)); + Set_Is_Preelaborated (Old_Main, Is_Preelaborated (New_Main)); + Set_Is_Remote_Types (Old_Main, Is_Remote_Types (New_Main)); + Set_Is_Shared_Passive (Old_Main, Is_Shared_Passive (New_Main)); + Set_Is_Remote_Call_Interface + (Old_Main, Is_Remote_Call_Interface (New_Main)); + end if; + + -- Make entry in Units table, so that binder can generate call to + -- elaboration procedure for body, if any. + + Make_Instance_Unit (Body_Cunit, In_Main => True); + Main_Unit_Entity := New_Main; + Set_Cunit_Entity (Main_Unit, Main_Unit_Entity); + + -- Build elaboration entity, since the instance may certainly generate + -- elaboration code requiring a flag for protection. + + Build_Elaboration_Entity (Decl_Cunit, New_Main); + end Build_Instance_Compilation_Unit_Nodes; + + ----------------------------- + -- Check_Access_Definition -- + ----------------------------- + + procedure Check_Access_Definition (N : Node_Id) is + begin + pragma Assert + (Ada_Version >= Ada_2005 and then Present (Access_Definition (N))); + null; + end Check_Access_Definition; + + ----------------------------------- + -- Check_Formal_Package_Instance -- + ----------------------------------- + + -- If the formal has specific parameters, they must match those of the + -- actual. Both of them are instances, and the renaming declarations for + -- their formal parameters appear in the same order in both. The analyzed + -- formal has been analyzed in the context of the current instance. + + procedure Check_Formal_Package_Instance + (Formal_Pack : Entity_Id; + Actual_Pack : Entity_Id) + is + E1 : Entity_Id := First_Entity (Actual_Pack); + E2 : Entity_Id := First_Entity (Formal_Pack); + + Expr1 : Node_Id; + Expr2 : Node_Id; + + procedure Check_Mismatch (B : Boolean); + -- Common error routine for mismatch between the parameters of the + -- actual instance and those of the formal package. + + function Same_Instantiated_Constant (E1, E2 : Entity_Id) return Boolean; + -- The formal may come from a nested formal package, and the actual may + -- have been constant-folded. To determine whether the two denote the + -- same entity we may have to traverse several definitions to recover + -- the ultimate entity that they refer to. + + function Same_Instantiated_Variable (E1, E2 : Entity_Id) return Boolean; + -- Similarly, if the formal comes from a nested formal package, the + -- actual may designate the formal through multiple renamings, which + -- have to be followed to determine the original variable in question. + + -------------------- + -- Check_Mismatch -- + -------------------- + + procedure Check_Mismatch (B : Boolean) is + Kind : constant Node_Kind := Nkind (Parent (E2)); + + begin + if Kind = N_Formal_Type_Declaration then + return; + + elsif Nkind_In (Kind, N_Formal_Object_Declaration, + N_Formal_Package_Declaration) + or else Kind in N_Formal_Subprogram_Declaration + then + null; + + elsif B then + Error_Msg_NE + ("actual for & in actual instance does not match formal", + Parent (Actual_Pack), E1); + end if; + end Check_Mismatch; + + -------------------------------- + -- Same_Instantiated_Constant -- + -------------------------------- + + function Same_Instantiated_Constant + (E1, E2 : Entity_Id) return Boolean + is + Ent : Entity_Id; + + begin + Ent := E2; + while Present (Ent) loop + if E1 = Ent then + return True; + + elsif Ekind (Ent) /= E_Constant then + return False; + + elsif Is_Entity_Name (Constant_Value (Ent)) then + if Entity (Constant_Value (Ent)) = E1 then + return True; + else + Ent := Entity (Constant_Value (Ent)); + end if; + + -- The actual may be a constant that has been folded. Recover + -- original name. + + elsif Is_Entity_Name (Original_Node (Constant_Value (Ent))) then + Ent := Entity (Original_Node (Constant_Value (Ent))); + else + return False; + end if; + end loop; + + return False; + end Same_Instantiated_Constant; + + -------------------------------- + -- Same_Instantiated_Variable -- + -------------------------------- + + function Same_Instantiated_Variable + (E1, E2 : Entity_Id) return Boolean + is + function Original_Entity (E : Entity_Id) return Entity_Id; + -- Follow chain of renamings to the ultimate ancestor + + --------------------- + -- Original_Entity -- + --------------------- + + function Original_Entity (E : Entity_Id) return Entity_Id is + Orig : Entity_Id; + + begin + Orig := E; + while Nkind (Parent (Orig)) = N_Object_Renaming_Declaration + and then Present (Renamed_Object (Orig)) + and then Is_Entity_Name (Renamed_Object (Orig)) + loop + Orig := Entity (Renamed_Object (Orig)); + end loop; + + return Orig; + end Original_Entity; + + -- Start of processing for Same_Instantiated_Variable + + begin + return Ekind (E1) = Ekind (E2) + and then Original_Entity (E1) = Original_Entity (E2); + end Same_Instantiated_Variable; + + -- Start of processing for Check_Formal_Package_Instance + + begin + while Present (E1) + and then Present (E2) + loop + exit when Ekind (E1) = E_Package + and then Renamed_Entity (E1) = Renamed_Entity (Actual_Pack); + + -- If the formal is the renaming of the formal package, this + -- is the end of its formal part, which may occur before the + -- end of the formal part in the actual in the presence of + -- defaulted parameters in the formal package. + + exit when Nkind (Parent (E2)) = N_Package_Renaming_Declaration + and then Renamed_Entity (E2) = Scope (E2); + + -- The analysis of the actual may generate additional internal + -- entities. If the formal is defaulted, there is no corresponding + -- analysis and the internal entities must be skipped, until we + -- find corresponding entities again. + + if Comes_From_Source (E2) + and then not Comes_From_Source (E1) + and then Chars (E1) /= Chars (E2) + then + while Present (E1) + and then Chars (E1) /= Chars (E2) + loop + Next_Entity (E1); + end loop; + end if; + + if No (E1) then + return; + + -- If the formal entity comes from a formal declaration, it was + -- defaulted in the formal package, and no check is needed on it. + + elsif Nkind (Parent (E2)) = N_Formal_Object_Declaration then + goto Next_E; + + -- Ditto for defaulted formal subprograms. + + elsif Is_Overloadable (E1) + and then Nkind (Unit_Declaration_Node (E2)) in + N_Formal_Subprogram_Declaration + then + goto Next_E; + + elsif Is_Type (E1) then + + -- Subtypes must statically match. E1, E2 are the local entities + -- that are subtypes of the actuals. Itypes generated for other + -- parameters need not be checked, the check will be performed + -- on the parameters themselves. + + -- If E2 is a formal type declaration, it is a defaulted parameter + -- and needs no checking. + + if not Is_Itype (E1) + and then not Is_Itype (E2) + then + Check_Mismatch + (not Is_Type (E2) + or else Etype (E1) /= Etype (E2) + or else not Subtypes_Statically_Match (E1, E2)); + end if; + + elsif Ekind (E1) = E_Constant then + + -- IN parameters must denote the same static value, or the same + -- constant, or the literal null. + + Expr1 := Expression (Parent (E1)); + + if Ekind (E2) /= E_Constant then + Check_Mismatch (True); + goto Next_E; + else + Expr2 := Expression (Parent (E2)); + end if; + + if Is_Static_Expression (Expr1) then + + if not Is_Static_Expression (Expr2) then + Check_Mismatch (True); + + elsif Is_Discrete_Type (Etype (E1)) then + declare + V1 : constant Uint := Expr_Value (Expr1); + V2 : constant Uint := Expr_Value (Expr2); + begin + Check_Mismatch (V1 /= V2); + end; + + elsif Is_Real_Type (Etype (E1)) then + declare + V1 : constant Ureal := Expr_Value_R (Expr1); + V2 : constant Ureal := Expr_Value_R (Expr2); + begin + Check_Mismatch (V1 /= V2); + end; + + elsif Is_String_Type (Etype (E1)) + and then Nkind (Expr1) = N_String_Literal + then + if Nkind (Expr2) /= N_String_Literal then + Check_Mismatch (True); + else + Check_Mismatch + (not String_Equal (Strval (Expr1), Strval (Expr2))); + end if; + end if; + + elsif Is_Entity_Name (Expr1) then + if Is_Entity_Name (Expr2) then + if Entity (Expr1) = Entity (Expr2) then + null; + else + Check_Mismatch + (not Same_Instantiated_Constant + (Entity (Expr1), Entity (Expr2))); + end if; + else + Check_Mismatch (True); + end if; + + elsif Is_Entity_Name (Original_Node (Expr1)) + and then Is_Entity_Name (Expr2) + and then + Same_Instantiated_Constant + (Entity (Original_Node (Expr1)), Entity (Expr2)) + then + null; + + elsif Nkind (Expr1) = N_Null then + Check_Mismatch (Nkind (Expr1) /= N_Null); + + else + Check_Mismatch (True); + end if; + + elsif Ekind (E1) = E_Variable then + Check_Mismatch (not Same_Instantiated_Variable (E1, E2)); + + elsif Ekind (E1) = E_Package then + Check_Mismatch + (Ekind (E1) /= Ekind (E2) + or else Renamed_Object (E1) /= Renamed_Object (E2)); + + elsif Is_Overloadable (E1) then + + -- Verify that the actual subprograms match. Note that actuals + -- that are attributes are rewritten as subprograms. If the + -- subprogram in the formal package is defaulted, no check is + -- needed. Note that this can only happen in Ada 2005 when the + -- formal package can be partially parameterized. + + if Nkind (Unit_Declaration_Node (E1)) = + N_Subprogram_Renaming_Declaration + and then From_Default (Unit_Declaration_Node (E1)) + then + null; + + -- If the formal package has an "others" box association that + -- covers this formal, there is no need for a check either. + + elsif Nkind (Unit_Declaration_Node (E2)) in + N_Formal_Subprogram_Declaration + and then Box_Present (Unit_Declaration_Node (E2)) + then + null; + + -- No check needed if subprogram is a defaulted null procedure + + elsif No (Alias (E2)) + and then Ekind (E2) = E_Procedure + and then + Null_Present (Specification (Unit_Declaration_Node (E2))) + then + null; + + -- Otherwise the actual in the formal and the actual in the + -- instantiation of the formal must match, up to renamings. + + else + Check_Mismatch + (Ekind (E2) /= Ekind (E1) or else (Alias (E1)) /= Alias (E2)); + end if; + + else + raise Program_Error; + end if; + + <<Next_E>> + Next_Entity (E1); + Next_Entity (E2); + end loop; + end Check_Formal_Package_Instance; + + --------------------------- + -- Check_Formal_Packages -- + --------------------------- + + procedure Check_Formal_Packages (P_Id : Entity_Id) is + E : Entity_Id; + Formal_P : Entity_Id; + + begin + -- Iterate through the declarations in the instance, looking for package + -- renaming declarations that denote instances of formal packages. Stop + -- when we find the renaming of the current package itself. The + -- declaration for a formal package without a box is followed by an + -- internal entity that repeats the instantiation. + + E := First_Entity (P_Id); + while Present (E) loop + if Ekind (E) = E_Package then + if Renamed_Object (E) = P_Id then + exit; + + elsif Nkind (Parent (E)) /= N_Package_Renaming_Declaration then + null; + + elsif not Box_Present (Parent (Associated_Formal_Package (E))) then + Formal_P := Next_Entity (E); + Check_Formal_Package_Instance (Formal_P, E); + + -- After checking, remove the internal validating package. It + -- is only needed for semantic checks, and as it may contain + -- generic formal declarations it should not reach gigi. + + Remove (Unit_Declaration_Node (Formal_P)); + end if; + end if; + + Next_Entity (E); + end loop; + end Check_Formal_Packages; + + --------------------------------- + -- Check_Forward_Instantiation -- + --------------------------------- + + procedure Check_Forward_Instantiation (Decl : Node_Id) is + S : Entity_Id; + Gen_Comp : Entity_Id := Cunit_Entity (Get_Source_Unit (Decl)); + + begin + -- The instantiation appears before the generic body if we are in the + -- scope of the unit containing the generic, either in its spec or in + -- the package body, and before the generic body. + + if Ekind (Gen_Comp) = E_Package_Body then + Gen_Comp := Spec_Entity (Gen_Comp); + end if; + + if In_Open_Scopes (Gen_Comp) + and then No (Corresponding_Body (Decl)) + then + S := Current_Scope; + + while Present (S) + and then not Is_Compilation_Unit (S) + and then not Is_Child_Unit (S) + loop + if Ekind (S) = E_Package then + Set_Has_Forward_Instantiation (S); + end if; + + S := Scope (S); + end loop; + end if; + end Check_Forward_Instantiation; + + --------------------------- + -- Check_Generic_Actuals -- + --------------------------- + + -- The visibility of the actuals may be different between the point of + -- generic instantiation and the instantiation of the body. + + procedure Check_Generic_Actuals + (Instance : Entity_Id; + Is_Formal_Box : Boolean) + is + E : Entity_Id; + Astype : Entity_Id; + + function Denotes_Previous_Actual (Typ : Entity_Id) return Boolean; + -- For a formal that is an array type, the component type is often a + -- previous formal in the same unit. The privacy status of the component + -- type will have been examined earlier in the traversal of the + -- corresponding actuals, and this status should not be modified for + -- the array (sub)type itself. However, if the base type of the array + -- (sub)type is private, its full view must be restored in the body to + -- be consistent with subsequent index subtypes, etc. + -- + -- To detect this case we have to rescan the list of formals, which is + -- usually short enough to ignore the resulting inefficiency. + + ----------------------------- + -- Denotes_Previous_Actual -- + ----------------------------- + + function Denotes_Previous_Actual (Typ : Entity_Id) return Boolean is + Prev : Entity_Id; + + begin + Prev := First_Entity (Instance); + while Present (Prev) loop + if Is_Type (Prev) + and then Nkind (Parent (Prev)) = N_Subtype_Declaration + and then Is_Entity_Name (Subtype_Indication (Parent (Prev))) + and then Entity (Subtype_Indication (Parent (Prev))) = Typ + then + return True; + + elsif Prev = E then + return False; + + else + Next_Entity (Prev); + end if; + end loop; + + return False; + end Denotes_Previous_Actual; + + -- Start of processing for Check_Generic_Actuals + + begin + E := First_Entity (Instance); + while Present (E) loop + if Is_Type (E) + and then Nkind (Parent (E)) = N_Subtype_Declaration + and then Scope (Etype (E)) /= Instance + and then Is_Entity_Name (Subtype_Indication (Parent (E))) + then + if Is_Array_Type (E) + and then not Is_Private_Type (Etype (E)) + and then Denotes_Previous_Actual (Component_Type (E)) + then + null; + else + Check_Private_View (Subtype_Indication (Parent (E))); + end if; + + Set_Is_Generic_Actual_Type (E, True); + Set_Is_Hidden (E, False); + Set_Is_Potentially_Use_Visible (E, + In_Use (Instance)); + + -- We constructed the generic actual type as a subtype of the + -- supplied type. This means that it normally would not inherit + -- subtype specific attributes of the actual, which is wrong for + -- the generic case. + + Astype := Ancestor_Subtype (E); + + if No (Astype) then + + -- This can happen when E is an itype that is the full view of + -- a private type completed, e.g. with a constrained array. In + -- that case, use the first subtype, which will carry size + -- information. The base type itself is unconstrained and will + -- not carry it. + + Astype := First_Subtype (E); + end if; + + Set_Size_Info (E, (Astype)); + Set_RM_Size (E, RM_Size (Astype)); + Set_First_Rep_Item (E, First_Rep_Item (Astype)); + + if Is_Discrete_Or_Fixed_Point_Type (E) then + Set_RM_Size (E, RM_Size (Astype)); + + -- In nested instances, the base type of an access actual may + -- itself be private, and need to be exchanged. + + elsif Is_Access_Type (E) + and then Is_Private_Type (Etype (E)) + then + Check_Private_View + (New_Occurrence_Of (Etype (E), Sloc (Instance))); + end if; + + elsif Ekind (E) = E_Package then + + -- If this is the renaming for the current instance, we're done. + -- Otherwise it is a formal package. If the corresponding formal + -- was declared with a box, the (instantiations of the) generic + -- formal part are also visible. Otherwise, ignore the entity + -- created to validate the actuals. + + if Renamed_Object (E) = Instance then + exit; + + elsif Nkind (Parent (E)) /= N_Package_Renaming_Declaration then + null; + + -- The visibility of a formal of an enclosing generic is already + -- correct. + + elsif Denotes_Formal_Package (E) then + null; + + elsif Present (Associated_Formal_Package (E)) + and then not Is_Generic_Formal (E) + then + if Box_Present (Parent (Associated_Formal_Package (E))) then + Check_Generic_Actuals (Renamed_Object (E), True); + + else + Check_Generic_Actuals (Renamed_Object (E), False); + end if; + + Set_Is_Hidden (E, False); + end if; + + -- If this is a subprogram instance (in a wrapper package) the + -- actual is fully visible. + + elsif Is_Wrapper_Package (Instance) then + Set_Is_Hidden (E, False); + + -- If the formal package is declared with a box, or if the formal + -- parameter is defaulted, it is visible in the body. + + elsif Is_Formal_Box + or else Is_Visible_Formal (E) + then + Set_Is_Hidden (E, False); + end if; + + if Ekind (E) = E_Constant then + + -- If the type of the actual is a private type declared in the + -- enclosing scope of the generic unit, the body of the generic + -- sees the full view of the type (because it has to appear in + -- the corresponding package body). If the type is private now, + -- exchange views to restore the proper visiblity in the instance. + + declare + Typ : constant Entity_Id := Base_Type (Etype (E)); + -- The type of the actual + + Gen_Id : Entity_Id; + -- The generic unit + + Parent_Scope : Entity_Id; + -- The enclosing scope of the generic unit + + begin + if Is_Wrapper_Package (Instance) then + Gen_Id := + Generic_Parent + (Specification + (Unit_Declaration_Node + (Related_Instance (Instance)))); + else + Gen_Id := + Generic_Parent (Package_Specification (Instance)); + end if; + + Parent_Scope := Scope (Gen_Id); + + -- The exchange is only needed if the generic is defined + -- within a package which is not a common ancestor of the + -- scope of the instance, and is not already in scope. + + if Is_Private_Type (Typ) + and then Scope (Typ) = Parent_Scope + and then Scope (Instance) /= Parent_Scope + and then Ekind (Parent_Scope) = E_Package + and then not Is_Child_Unit (Gen_Id) + then + Switch_View (Typ); + + -- If the type of the entity is a subtype, it may also have + -- to be made visible, together with the base type of its + -- full view, after exchange. + + if Is_Private_Type (Etype (E)) then + Switch_View (Etype (E)); + Switch_View (Base_Type (Etype (E))); + end if; + end if; + end; + end if; + + Next_Entity (E); + end loop; + end Check_Generic_Actuals; + + ------------------------------ + -- Check_Generic_Child_Unit -- + ------------------------------ + + procedure Check_Generic_Child_Unit + (Gen_Id : Node_Id; + Parent_Installed : in out Boolean) + is + Loc : constant Source_Ptr := Sloc (Gen_Id); + Gen_Par : Entity_Id := Empty; + E : Entity_Id; + Inst_Par : Entity_Id; + S : Node_Id; + + function Find_Generic_Child + (Scop : Entity_Id; + Id : Node_Id) return Entity_Id; + -- Search generic parent for possible child unit with the given name + + function In_Enclosing_Instance return Boolean; + -- Within an instance of the parent, the child unit may be denoted by + -- a simple name, or an abbreviated expanded name. Examine enclosing + -- scopes to locate a possible parent instantiation. + + ------------------------ + -- Find_Generic_Child -- + ------------------------ + + function Find_Generic_Child + (Scop : Entity_Id; + Id : Node_Id) return Entity_Id + is + E : Entity_Id; + + begin + -- If entity of name is already set, instance has already been + -- resolved, e.g. in an enclosing instantiation. + + if Present (Entity (Id)) then + if Scope (Entity (Id)) = Scop then + return Entity (Id); + else + return Empty; + end if; + + else + E := First_Entity (Scop); + while Present (E) loop + if Chars (E) = Chars (Id) + and then Is_Child_Unit (E) + then + if Is_Child_Unit (E) + and then not Is_Visible_Lib_Unit (E) + then + Error_Msg_NE + ("generic child unit& is not visible", Gen_Id, E); + end if; + + Set_Entity (Id, E); + return E; + end if; + + Next_Entity (E); + end loop; + + return Empty; + end if; + end Find_Generic_Child; + + --------------------------- + -- In_Enclosing_Instance -- + --------------------------- + + function In_Enclosing_Instance return Boolean is + Enclosing_Instance : Node_Id; + Instance_Decl : Node_Id; + + begin + -- We do not inline any call that contains instantiations, except + -- for instantiations of Unchecked_Conversion, so if we are within + -- an inlined body the current instance does not require parents. + + if In_Inlined_Body then + pragma Assert (Chars (Gen_Id) = Name_Unchecked_Conversion); + return False; + end if; + + -- Loop to check enclosing scopes + + Enclosing_Instance := Current_Scope; + while Present (Enclosing_Instance) loop + Instance_Decl := Unit_Declaration_Node (Enclosing_Instance); + + if Ekind (Enclosing_Instance) = E_Package + and then Is_Generic_Instance (Enclosing_Instance) + and then Present + (Generic_Parent (Specification (Instance_Decl))) + then + -- Check whether the generic we are looking for is a child of + -- this instance. + + E := Find_Generic_Child + (Generic_Parent (Specification (Instance_Decl)), Gen_Id); + exit when Present (E); + + else + E := Empty; + end if; + + Enclosing_Instance := Scope (Enclosing_Instance); + end loop; + + if No (E) then + + -- Not a child unit + + Analyze (Gen_Id); + return False; + + else + Rewrite (Gen_Id, + Make_Expanded_Name (Loc, + Chars => Chars (E), + Prefix => New_Occurrence_Of (Enclosing_Instance, Loc), + Selector_Name => New_Occurrence_Of (E, Loc))); + + Set_Entity (Gen_Id, E); + Set_Etype (Gen_Id, Etype (E)); + Parent_Installed := False; -- Already in scope. + return True; + end if; + end In_Enclosing_Instance; + + -- Start of processing for Check_Generic_Child_Unit + + begin + -- If the name of the generic is given by a selected component, it may + -- be the name of a generic child unit, and the prefix is the name of an + -- instance of the parent, in which case the child unit must be visible. + -- If this instance is not in scope, it must be placed there and removed + -- after instantiation, because what is being instantiated is not the + -- original child, but the corresponding child present in the instance + -- of the parent. + + -- If the child is instantiated within the parent, it can be given by + -- a simple name. In this case the instance is already in scope, but + -- the child generic must be recovered from the generic parent as well. + + if Nkind (Gen_Id) = N_Selected_Component then + S := Selector_Name (Gen_Id); + Analyze (Prefix (Gen_Id)); + Inst_Par := Entity (Prefix (Gen_Id)); + + if Ekind (Inst_Par) = E_Package + and then Present (Renamed_Object (Inst_Par)) + then + Inst_Par := Renamed_Object (Inst_Par); + end if; + + if Ekind (Inst_Par) = E_Package then + if Nkind (Parent (Inst_Par)) = N_Package_Specification then + Gen_Par := Generic_Parent (Parent (Inst_Par)); + + elsif Nkind (Parent (Inst_Par)) = N_Defining_Program_Unit_Name + and then + Nkind (Parent (Parent (Inst_Par))) = N_Package_Specification + then + Gen_Par := Generic_Parent (Parent (Parent (Inst_Par))); + end if; + + elsif Ekind (Inst_Par) = E_Generic_Package + and then Nkind (Parent (Gen_Id)) = N_Formal_Package_Declaration + then + -- A formal package may be a real child package, and not the + -- implicit instance within a parent. In this case the child is + -- not visible and has to be retrieved explicitly as well. + + Gen_Par := Inst_Par; + end if; + + if Present (Gen_Par) then + + -- The prefix denotes an instantiation. The entity itself may be a + -- nested generic, or a child unit. + + E := Find_Generic_Child (Gen_Par, S); + + if Present (E) then + Change_Selected_Component_To_Expanded_Name (Gen_Id); + Set_Entity (Gen_Id, E); + Set_Etype (Gen_Id, Etype (E)); + Set_Entity (S, E); + Set_Etype (S, Etype (E)); + + -- Indicate that this is a reference to the parent + + if In_Extended_Main_Source_Unit (Gen_Id) then + Set_Is_Instantiated (Inst_Par); + end if; + + -- A common mistake is to replicate the naming scheme of a + -- hierarchy by instantiating a generic child directly, rather + -- than the implicit child in a parent instance: + + -- generic .. package Gpar is .. + -- generic .. package Gpar.Child is .. + -- package Par is new Gpar (); + + -- with Gpar.Child; + -- package Par.Child is new Gpar.Child (); + -- rather than Par.Child + + -- In this case the instantiation is within Par, which is an + -- instance, but Gpar does not denote Par because we are not IN + -- the instance of Gpar, so this is illegal. The test below + -- recognizes this particular case. + + if Is_Child_Unit (E) + and then not Comes_From_Source (Entity (Prefix (Gen_Id))) + and then (not In_Instance + or else Nkind (Parent (Parent (Gen_Id))) = + N_Compilation_Unit) + then + Error_Msg_N + ("prefix of generic child unit must be instance of parent", + Gen_Id); + end if; + + if not In_Open_Scopes (Inst_Par) + and then Nkind (Parent (Gen_Id)) not in + N_Generic_Renaming_Declaration + then + Install_Parent (Inst_Par); + Parent_Installed := True; + + elsif In_Open_Scopes (Inst_Par) then + + -- If the parent is already installed, install the actuals + -- for its formal packages. This is necessary when the child + -- instance is a child of the parent instance: in this case, + -- the parent is placed on the scope stack but the formal + -- packages are not made visible. + + Install_Formal_Packages (Inst_Par); + end if; + + else + -- If the generic parent does not contain an entity that + -- corresponds to the selector, the instance doesn't either. + -- Analyzing the node will yield the appropriate error message. + -- If the entity is not a child unit, then it is an inner + -- generic in the parent. + + Analyze (Gen_Id); + end if; + + else + Analyze (Gen_Id); + + if Is_Child_Unit (Entity (Gen_Id)) + and then + Nkind (Parent (Gen_Id)) not in N_Generic_Renaming_Declaration + and then not In_Open_Scopes (Inst_Par) + then + Install_Parent (Inst_Par); + Parent_Installed := True; + + -- The generic unit may be the renaming of the implicit child + -- present in an instance. In that case the parent instance is + -- obtained from the name of the renamed entity. + + elsif Ekind (Entity (Gen_Id)) = E_Generic_Package + and then Present (Renamed_Entity (Entity (Gen_Id))) + and then Is_Child_Unit (Renamed_Entity (Entity (Gen_Id))) + then + declare + Renamed_Package : constant Node_Id := + Name (Parent (Entity (Gen_Id))); + begin + if Nkind (Renamed_Package) = N_Expanded_Name then + Inst_Par := Entity (Prefix (Renamed_Package)); + Install_Parent (Inst_Par); + Parent_Installed := True; + end if; + end; + end if; + end if; + + elsif Nkind (Gen_Id) = N_Expanded_Name then + + -- Entity already present, analyze prefix, whose meaning may be + -- an instance in the current context. If it is an instance of + -- a relative within another, the proper parent may still have + -- to be installed, if they are not of the same generation. + + Analyze (Prefix (Gen_Id)); + + -- In the unlikely case that a local declaration hides the name + -- of the parent package, locate it on the homonym chain. If the + -- context is an instance of the parent, the renaming entity is + -- flagged as such. + + Inst_Par := Entity (Prefix (Gen_Id)); + while Present (Inst_Par) + and then not Is_Package_Or_Generic_Package (Inst_Par) + loop + Inst_Par := Homonym (Inst_Par); + end loop; + + pragma Assert (Present (Inst_Par)); + Set_Entity (Prefix (Gen_Id), Inst_Par); + + if In_Enclosing_Instance then + null; + + elsif Present (Entity (Gen_Id)) + and then Is_Child_Unit (Entity (Gen_Id)) + and then not In_Open_Scopes (Inst_Par) + then + Install_Parent (Inst_Par); + Parent_Installed := True; + end if; + + elsif In_Enclosing_Instance then + + -- The child unit is found in some enclosing scope + + null; + + else + Analyze (Gen_Id); + + -- If this is the renaming of the implicit child in a parent + -- instance, recover the parent name and install it. + + if Is_Entity_Name (Gen_Id) then + E := Entity (Gen_Id); + + if Is_Generic_Unit (E) + and then Nkind (Parent (E)) in N_Generic_Renaming_Declaration + and then Is_Child_Unit (Renamed_Object (E)) + and then Is_Generic_Unit (Scope (Renamed_Object (E))) + and then Nkind (Name (Parent (E))) = N_Expanded_Name + then + Rewrite (Gen_Id, + New_Copy_Tree (Name (Parent (E)))); + Inst_Par := Entity (Prefix (Gen_Id)); + + if not In_Open_Scopes (Inst_Par) then + Install_Parent (Inst_Par); + Parent_Installed := True; + end if; + + -- If it is a child unit of a non-generic parent, it may be + -- use-visible and given by a direct name. Install parent as + -- for other cases. + + elsif Is_Generic_Unit (E) + and then Is_Child_Unit (E) + and then + Nkind (Parent (Gen_Id)) not in N_Generic_Renaming_Declaration + and then not Is_Generic_Unit (Scope (E)) + then + if not In_Open_Scopes (Scope (E)) then + Install_Parent (Scope (E)); + Parent_Installed := True; + end if; + end if; + end if; + end if; + end Check_Generic_Child_Unit; + + ----------------------------- + -- Check_Hidden_Child_Unit -- + ----------------------------- + + procedure Check_Hidden_Child_Unit + (N : Node_Id; + Gen_Unit : Entity_Id; + Act_Decl_Id : Entity_Id) + is + Gen_Id : constant Node_Id := Name (N); + + begin + if Is_Child_Unit (Gen_Unit) + and then Is_Child_Unit (Act_Decl_Id) + and then Nkind (Gen_Id) = N_Expanded_Name + and then Entity (Prefix (Gen_Id)) = Scope (Act_Decl_Id) + and then Chars (Gen_Unit) = Chars (Act_Decl_Id) + then + Error_Msg_Node_2 := Scope (Act_Decl_Id); + Error_Msg_NE + ("generic unit & is implicitly declared in &", + Defining_Unit_Name (N), Gen_Unit); + Error_Msg_N ("\instance must have different name", + Defining_Unit_Name (N)); + end if; + end Check_Hidden_Child_Unit; + + ------------------------ + -- Check_Private_View -- + ------------------------ + + procedure Check_Private_View (N : Node_Id) is + T : constant Entity_Id := Etype (N); + BT : Entity_Id; + + begin + -- Exchange views if the type was not private in the generic but is + -- private at the point of instantiation. Do not exchange views if + -- the scope of the type is in scope. This can happen if both generic + -- and instance are sibling units, or if type is defined in a parent. + -- In this case the visibility of the type will be correct for all + -- semantic checks. + + if Present (T) then + BT := Base_Type (T); + + if Is_Private_Type (T) + and then not Has_Private_View (N) + and then Present (Full_View (T)) + and then not In_Open_Scopes (Scope (T)) + then + -- In the generic, the full type was visible. Save the private + -- entity, for subsequent exchange. + + Switch_View (T); + + elsif Has_Private_View (N) + and then not Is_Private_Type (T) + and then not Has_Been_Exchanged (T) + and then Etype (Get_Associated_Node (N)) /= T + then + -- Only the private declaration was visible in the generic. If + -- the type appears in a subtype declaration, the subtype in the + -- instance must have a view compatible with that of its parent, + -- which must be exchanged (see corresponding code in Restore_ + -- Private_Views). Otherwise, if the type is defined in a parent + -- unit, leave full visibility within instance, which is safe. + + if In_Open_Scopes (Scope (Base_Type (T))) + and then not Is_Private_Type (Base_Type (T)) + and then Comes_From_Source (Base_Type (T)) + then + null; + + elsif Nkind (Parent (N)) = N_Subtype_Declaration + or else not In_Private_Part (Scope (Base_Type (T))) + then + Prepend_Elmt (T, Exchanged_Views); + Exchange_Declarations (Etype (Get_Associated_Node (N))); + end if; + + -- For composite types with inconsistent representation exchange + -- component types accordingly. + + elsif Is_Access_Type (T) + and then Is_Private_Type (Designated_Type (T)) + and then not Has_Private_View (N) + and then Present (Full_View (Designated_Type (T))) + then + Switch_View (Designated_Type (T)); + + elsif Is_Array_Type (T) then + if Is_Private_Type (Component_Type (T)) + and then not Has_Private_View (N) + and then Present (Full_View (Component_Type (T))) + then + Switch_View (Component_Type (T)); + end if; + + -- The normal exchange mechanism relies on the setting of a + -- flag on the reference in the generic. However, an additional + -- mechanism is needed for types that are not explicitly + -- mentioned in the generic, but may be needed in expanded code + -- in the instance. This includes component types of arrays and + -- designated types of access types. This processing must also + -- include the index types of arrays which we take care of here. + + declare + Indx : Node_Id; + Typ : Entity_Id; + + begin + Indx := First_Index (T); + while Present (Indx) loop + Typ := Base_Type (Etype (Indx)); + + if Is_Private_Type (Typ) + and then Present (Full_View (Typ)) + then + Switch_View (Typ); + end if; + + Next_Index (Indx); + end loop; + end; + + elsif Is_Private_Type (T) + and then Present (Full_View (T)) + and then Is_Array_Type (Full_View (T)) + and then Is_Private_Type (Component_Type (Full_View (T))) + then + Switch_View (T); + + -- Finally, a non-private subtype may have a private base type, which + -- must be exchanged for consistency. This can happen when a package + -- body is instantiated, when the scope stack is empty but in fact + -- the subtype and the base type are declared in an enclosing scope. + + -- Note that in this case we introduce an inconsistency in the view + -- set, because we switch the base type BT, but there could be some + -- private dependent subtypes of BT which remain unswitched. Such + -- subtypes might need to be switched at a later point (see specific + -- provision for that case in Switch_View). + + elsif not Is_Private_Type (T) + and then not Has_Private_View (N) + and then Is_Private_Type (BT) + and then Present (Full_View (BT)) + and then not Is_Generic_Type (BT) + and then not In_Open_Scopes (BT) + then + Prepend_Elmt (Full_View (BT), Exchanged_Views); + Exchange_Declarations (BT); + end if; + end if; + end Check_Private_View; + + ----------------------------- + -- Check_Hidden_Primitives -- + ----------------------------- + + function Check_Hidden_Primitives (Assoc_List : List_Id) return Elist_Id is + Actual : Node_Id; + Gen_T : Entity_Id; + Result : Elist_Id := No_Elist; + + begin + if No (Assoc_List) then + return No_Elist; + end if; + + -- Traverse the list of associations between formals and actuals + -- searching for renamings of tagged types + + Actual := First (Assoc_List); + while Present (Actual) loop + if Nkind (Actual) = N_Subtype_Declaration then + Gen_T := Generic_Parent_Type (Actual); + + if Present (Gen_T) + and then Is_Tagged_Type (Gen_T) + then + -- Traverse the list of primitives of the actual types + -- searching for hidden primitives that are visible in the + -- corresponding generic formal; leave them visible and + -- append them to Result to restore their decoration later. + + Install_Hidden_Primitives + (Prims_List => Result, + Gen_T => Gen_T, + Act_T => Entity (Subtype_Indication (Actual))); + end if; + end if; + + Next (Actual); + end loop; + + return Result; + end Check_Hidden_Primitives; + + -------------------------- + -- Contains_Instance_Of -- + -------------------------- + + function Contains_Instance_Of + (Inner : Entity_Id; + Outer : Entity_Id; + N : Node_Id) return Boolean + is + Elmt : Elmt_Id; + Scop : Entity_Id; + + begin + Scop := Outer; + + -- Verify that there are no circular instantiations. We check whether + -- the unit contains an instance of the current scope or some enclosing + -- scope (in case one of the instances appears in a subunit). Longer + -- circularities involving subunits might seem too pathological to + -- consider, but they were not too pathological for the authors of + -- DEC bc30vsq, so we loop over all enclosing scopes, and mark all + -- enclosing generic scopes as containing an instance. + + loop + -- Within a generic subprogram body, the scope is not generic, to + -- allow for recursive subprograms. Use the declaration to determine + -- whether this is a generic unit. + + if Ekind (Scop) = E_Generic_Package + or else (Is_Subprogram (Scop) + and then Nkind (Unit_Declaration_Node (Scop)) = + N_Generic_Subprogram_Declaration) + then + Elmt := First_Elmt (Inner_Instances (Inner)); + + while Present (Elmt) loop + if Node (Elmt) = Scop then + Error_Msg_Node_2 := Inner; + Error_Msg_NE + ("circular Instantiation: & instantiated within &!", + N, Scop); + return True; + + elsif Node (Elmt) = Inner then + return True; + + elsif Contains_Instance_Of (Node (Elmt), Scop, N) then + Error_Msg_Node_2 := Inner; + Error_Msg_NE + ("circular Instantiation: & instantiated within &!", + N, Node (Elmt)); + return True; + end if; + + Next_Elmt (Elmt); + end loop; + + -- Indicate that Inner is being instantiated within Scop + + Append_Elmt (Inner, Inner_Instances (Scop)); + end if; + + if Scop = Standard_Standard then + exit; + else + Scop := Scope (Scop); + end if; + end loop; + + return False; + end Contains_Instance_Of; + + ----------------------- + -- Copy_Generic_Node -- + ----------------------- + + function Copy_Generic_Node + (N : Node_Id; + Parent_Id : Node_Id; + Instantiating : Boolean) return Node_Id + is + Ent : Entity_Id; + New_N : Node_Id; + + function Copy_Generic_Descendant (D : Union_Id) return Union_Id; + -- Check the given value of one of the Fields referenced by the current + -- node to determine whether to copy it recursively. The field may hold + -- a Node_Id, a List_Id, or an Elist_Id, or a plain value (Sloc, Uint, + -- Char) in which case it need not be copied. + + procedure Copy_Descendants; + -- Common utility for various nodes + + function Copy_Generic_Elist (E : Elist_Id) return Elist_Id; + -- Make copy of element list + + function Copy_Generic_List + (L : List_Id; + Parent_Id : Node_Id) return List_Id; + -- Apply Copy_Node recursively to the members of a node list + + function In_Defining_Unit_Name (Nam : Node_Id) return Boolean; + -- True if an identifier is part of the defining program unit name of + -- a child unit. The entity of such an identifier must be kept (for + -- ASIS use) even though as the name of an enclosing generic it would + -- otherwise not be preserved in the generic tree. + + ---------------------- + -- Copy_Descendants -- + ---------------------- + + procedure Copy_Descendants is + + use Atree.Unchecked_Access; + -- This code section is part of the implementation of an untyped + -- tree traversal, so it needs direct access to node fields. + + begin + Set_Field1 (New_N, Copy_Generic_Descendant (Field1 (N))); + Set_Field2 (New_N, Copy_Generic_Descendant (Field2 (N))); + Set_Field3 (New_N, Copy_Generic_Descendant (Field3 (N))); + Set_Field4 (New_N, Copy_Generic_Descendant (Field4 (N))); + Set_Field5 (New_N, Copy_Generic_Descendant (Field5 (N))); + end Copy_Descendants; + + ----------------------------- + -- Copy_Generic_Descendant -- + ----------------------------- + + function Copy_Generic_Descendant (D : Union_Id) return Union_Id is + begin + if D = Union_Id (Empty) then + return D; + + elsif D in Node_Range then + return Union_Id + (Copy_Generic_Node (Node_Id (D), New_N, Instantiating)); + + elsif D in List_Range then + return Union_Id (Copy_Generic_List (List_Id (D), New_N)); + + elsif D in Elist_Range then + return Union_Id (Copy_Generic_Elist (Elist_Id (D))); + + -- Nothing else is copyable (e.g. Uint values), return as is + + else + return D; + end if; + end Copy_Generic_Descendant; + + ------------------------ + -- Copy_Generic_Elist -- + ------------------------ + + function Copy_Generic_Elist (E : Elist_Id) return Elist_Id is + M : Elmt_Id; + L : Elist_Id; + + begin + if Present (E) then + L := New_Elmt_List; + M := First_Elmt (E); + while Present (M) loop + Append_Elmt + (Copy_Generic_Node (Node (M), Empty, Instantiating), L); + Next_Elmt (M); + end loop; + + return L; + + else + return No_Elist; + end if; + end Copy_Generic_Elist; + + ----------------------- + -- Copy_Generic_List -- + ----------------------- + + function Copy_Generic_List + (L : List_Id; + Parent_Id : Node_Id) return List_Id + is + N : Node_Id; + New_L : List_Id; + + begin + if Present (L) then + New_L := New_List; + Set_Parent (New_L, Parent_Id); + + N := First (L); + while Present (N) loop + Append (Copy_Generic_Node (N, Empty, Instantiating), New_L); + Next (N); + end loop; + + return New_L; + + else + return No_List; + end if; + end Copy_Generic_List; + + --------------------------- + -- In_Defining_Unit_Name -- + --------------------------- + + function In_Defining_Unit_Name (Nam : Node_Id) return Boolean is + begin + return Present (Parent (Nam)) + and then (Nkind (Parent (Nam)) = N_Defining_Program_Unit_Name + or else + (Nkind (Parent (Nam)) = N_Expanded_Name + and then In_Defining_Unit_Name (Parent (Nam)))); + end In_Defining_Unit_Name; + + -- Start of processing for Copy_Generic_Node + + begin + if N = Empty then + return N; + end if; + + New_N := New_Copy (N); + + -- Copy aspects if present + + if Has_Aspects (N) then + Set_Has_Aspects (New_N, False); + Set_Aspect_Specifications + (New_N, Copy_Generic_List (Aspect_Specifications (N), Parent_Id)); + end if; + + if Instantiating then + Adjust_Instantiation_Sloc (New_N, S_Adjustment); + end if; + + if not Is_List_Member (N) then + Set_Parent (New_N, Parent_Id); + end if; + + -- If defining identifier, then all fields have been copied already + + if Nkind (New_N) in N_Entity then + null; + + -- Special casing for identifiers and other entity names and operators + + elsif Nkind_In (New_N, N_Identifier, + N_Character_Literal, + N_Expanded_Name, + N_Operator_Symbol) + or else Nkind (New_N) in N_Op + then + if not Instantiating then + + -- Link both nodes in order to assign subsequently the entity of + -- the copy to the original node, in case this is a global + -- reference. + + Set_Associated_Node (N, New_N); + + -- If we are within an instantiation, this is a nested generic + -- that has already been analyzed at the point of definition. + -- We must preserve references that were global to the enclosing + -- parent at that point. Other occurrences, whether global or + -- local to the current generic, must be resolved anew, so we + -- reset the entity in the generic copy. A global reference has a + -- smaller depth than the parent, or else the same depth in case + -- both are distinct compilation units. + + -- A child unit is implicitly declared within the enclosing parent + -- but is in fact global to it, and must be preserved. + + -- It is also possible for Current_Instantiated_Parent to be + -- defined, and for this not to be a nested generic, namely if + -- the unit is loaded through Rtsfind. In that case, the entity of + -- New_N is only a link to the associated node, and not a defining + -- occurrence. + + -- The entities for parent units in the defining_program_unit of a + -- generic child unit are established when the context of the unit + -- is first analyzed, before the generic copy is made. They are + -- preserved in the copy for use in ASIS queries. + + Ent := Entity (New_N); + + if No (Current_Instantiated_Parent.Gen_Id) then + if No (Ent) + or else Nkind (Ent) /= N_Defining_Identifier + or else not In_Defining_Unit_Name (N) + then + Set_Associated_Node (New_N, Empty); + end if; + + elsif No (Ent) + or else + not Nkind_In (Ent, N_Defining_Identifier, + N_Defining_Character_Literal, + N_Defining_Operator_Symbol) + or else No (Scope (Ent)) + or else + (Scope (Ent) = Current_Instantiated_Parent.Gen_Id + and then not Is_Child_Unit (Ent)) + or else + (Scope_Depth (Scope (Ent)) > + Scope_Depth (Current_Instantiated_Parent.Gen_Id) + and then + Get_Source_Unit (Ent) = + Get_Source_Unit (Current_Instantiated_Parent.Gen_Id)) + then + Set_Associated_Node (New_N, Empty); + end if; + + -- Case of instantiating identifier or some other name or operator + + else + -- If the associated node is still defined, the entity in it + -- is global, and must be copied to the instance. If this copy + -- is being made for a body to inline, it is applied to an + -- instantiated tree, and the entity is already present and + -- must be also preserved. + + declare + Assoc : constant Node_Id := Get_Associated_Node (N); + + begin + if Present (Assoc) then + if Nkind (Assoc) = Nkind (N) then + Set_Entity (New_N, Entity (Assoc)); + Check_Private_View (N); + + -- The name in the call may be a selected component if the + -- call has not been analyzed yet, as may be the case for + -- pre/post conditions in a generic unit. + + elsif Nkind (Assoc) = N_Function_Call + and then Is_Entity_Name (Name (Assoc)) + then + Set_Entity (New_N, Entity (Name (Assoc))); + + elsif Nkind_In (Assoc, N_Defining_Identifier, + N_Defining_Character_Literal, + N_Defining_Operator_Symbol) + and then Expander_Active + then + -- Inlining case: we are copying a tree that contains + -- global entities, which are preserved in the copy to be + -- used for subsequent inlining. + + null; + + else + Set_Entity (New_N, Empty); + end if; + end if; + end; + end if; + + -- For expanded name, we must copy the Prefix and Selector_Name + + if Nkind (N) = N_Expanded_Name then + Set_Prefix + (New_N, Copy_Generic_Node (Prefix (N), New_N, Instantiating)); + + Set_Selector_Name (New_N, + Copy_Generic_Node (Selector_Name (N), New_N, Instantiating)); + + -- For operators, we must copy the right operand + + elsif Nkind (N) in N_Op then + Set_Right_Opnd (New_N, + Copy_Generic_Node (Right_Opnd (N), New_N, Instantiating)); + + -- And for binary operators, the left operand as well + + if Nkind (N) in N_Binary_Op then + Set_Left_Opnd (New_N, + Copy_Generic_Node (Left_Opnd (N), New_N, Instantiating)); + end if; + end if; + + -- Special casing for stubs + + elsif Nkind (N) in N_Body_Stub then + + -- In any case, we must copy the specification or defining + -- identifier as appropriate. + + if Nkind (N) = N_Subprogram_Body_Stub then + Set_Specification (New_N, + Copy_Generic_Node (Specification (N), New_N, Instantiating)); + + else + Set_Defining_Identifier (New_N, + Copy_Generic_Node + (Defining_Identifier (N), New_N, Instantiating)); + end if; + + -- If we are not instantiating, then this is where we load and + -- analyze subunits, i.e. at the point where the stub occurs. A + -- more permissive system might defer this analysis to the point + -- of instantiation, but this seems too complicated for now. + + if not Instantiating then + declare + Subunit_Name : constant Unit_Name_Type := Get_Unit_Name (N); + Subunit : Node_Id; + Unum : Unit_Number_Type; + New_Body : Node_Id; + + begin + -- Make sure that, if it is a subunit of the main unit that is + -- preprocessed and if -gnateG is specified, the preprocessed + -- file will be written. + + Lib.Analysing_Subunit_Of_Main := + Lib.In_Extended_Main_Source_Unit (N); + Unum := + Load_Unit + (Load_Name => Subunit_Name, + Required => False, + Subunit => True, + Error_Node => N); + Lib.Analysing_Subunit_Of_Main := False; + + -- If the proper body is not found, a warning message will be + -- emitted when analyzing the stub, or later at the point of + -- instantiation. Here we just leave the stub as is. + + if Unum = No_Unit then + Subunits_Missing := True; + goto Subunit_Not_Found; + end if; + + Subunit := Cunit (Unum); + + if Nkind (Unit (Subunit)) /= N_Subunit then + Error_Msg_N + ("found child unit instead of expected SEPARATE subunit", + Subunit); + Error_Msg_Sloc := Sloc (N); + Error_Msg_N ("\to complete stub #", Subunit); + goto Subunit_Not_Found; + end if; + + -- We must create a generic copy of the subunit, in order to + -- perform semantic analysis on it, and we must replace the + -- stub in the original generic unit with the subunit, in order + -- to preserve non-local references within. + + -- Only the proper body needs to be copied. Library_Unit and + -- context clause are simply inherited by the generic copy. + -- Note that the copy (which may be recursive if there are + -- nested subunits) must be done first, before attaching it to + -- the enclosing generic. + + New_Body := + Copy_Generic_Node + (Proper_Body (Unit (Subunit)), + Empty, Instantiating => False); + + -- Now place the original proper body in the original generic + -- unit. This is a body, not a compilation unit. + + Rewrite (N, Proper_Body (Unit (Subunit))); + Set_Is_Compilation_Unit (Defining_Entity (N), False); + Set_Was_Originally_Stub (N); + + -- Finally replace the body of the subunit with its copy, and + -- make this new subunit into the library unit of the generic + -- copy, which does not have stubs any longer. + + Set_Proper_Body (Unit (Subunit), New_Body); + Set_Library_Unit (New_N, Subunit); + Inherit_Context (Unit (Subunit), N); + end; + + -- If we are instantiating, this must be an error case, since + -- otherwise we would have replaced the stub node by the proper body + -- that corresponds. So just ignore it in the copy (i.e. we have + -- copied it, and that is good enough). + + else + null; + end if; + + <<Subunit_Not_Found>> null; + + -- If the node is a compilation unit, it is the subunit of a stub, which + -- has been loaded already (see code below). In this case, the library + -- unit field of N points to the parent unit (which is a compilation + -- unit) and need not (and cannot) be copied. + + -- When the proper body of the stub is analyzed, the library_unit link + -- is used to establish the proper context (see sem_ch10). + + -- The other fields of a compilation unit are copied as usual + + elsif Nkind (N) = N_Compilation_Unit then + + -- This code can only be executed when not instantiating, because in + -- the copy made for an instantiation, the compilation unit node has + -- disappeared at the point that a stub is replaced by its proper + -- body. + + pragma Assert (not Instantiating); + + Set_Context_Items (New_N, + Copy_Generic_List (Context_Items (N), New_N)); + + Set_Unit (New_N, + Copy_Generic_Node (Unit (N), New_N, False)); + + Set_First_Inlined_Subprogram (New_N, + Copy_Generic_Node + (First_Inlined_Subprogram (N), New_N, False)); + + Set_Aux_Decls_Node (New_N, + Copy_Generic_Node (Aux_Decls_Node (N), New_N, False)); + + -- For an assignment node, the assignment is known to be semantically + -- legal if we are instantiating the template. This avoids incorrect + -- diagnostics in generated code. + + elsif Nkind (N) = N_Assignment_Statement then + + -- Copy name and expression fields in usual manner + + Set_Name (New_N, + Copy_Generic_Node (Name (N), New_N, Instantiating)); + + Set_Expression (New_N, + Copy_Generic_Node (Expression (N), New_N, Instantiating)); + + if Instantiating then + Set_Assignment_OK (Name (New_N), True); + end if; + + elsif Nkind_In (N, N_Aggregate, N_Extension_Aggregate) then + if not Instantiating then + Set_Associated_Node (N, New_N); + + else + if Present (Get_Associated_Node (N)) + and then Nkind (Get_Associated_Node (N)) = Nkind (N) + then + -- In the generic the aggregate has some composite type. If at + -- the point of instantiation the type has a private view, + -- install the full view (and that of its ancestors, if any). + + declare + T : Entity_Id := (Etype (Get_Associated_Node (New_N))); + Rt : Entity_Id; + + begin + if Present (T) + and then Is_Private_Type (T) + then + Switch_View (T); + end if; + + if Present (T) + and then Is_Tagged_Type (T) + and then Is_Derived_Type (T) + then + Rt := Root_Type (T); + + loop + T := Etype (T); + + if Is_Private_Type (T) then + Switch_View (T); + end if; + + exit when T = Rt; + end loop; + end if; + end; + end if; + end if; + + -- Do not copy the associated node, which points to the generic copy + -- of the aggregate. + + declare + use Atree.Unchecked_Access; + -- This code section is part of the implementation of an untyped + -- tree traversal, so it needs direct access to node fields. + + begin + Set_Field1 (New_N, Copy_Generic_Descendant (Field1 (N))); + Set_Field2 (New_N, Copy_Generic_Descendant (Field2 (N))); + Set_Field3 (New_N, Copy_Generic_Descendant (Field3 (N))); + Set_Field5 (New_N, Copy_Generic_Descendant (Field5 (N))); + end; + + -- Allocators do not have an identifier denoting the access type, so we + -- must locate it through the expression to check whether the views are + -- consistent. + + elsif Nkind (N) = N_Allocator + and then Nkind (Expression (N)) = N_Qualified_Expression + and then Is_Entity_Name (Subtype_Mark (Expression (N))) + and then Instantiating + then + declare + T : constant Node_Id := + Get_Associated_Node (Subtype_Mark (Expression (N))); + Acc_T : Entity_Id; + + begin + if Present (T) then + + -- Retrieve the allocator node in the generic copy + + Acc_T := Etype (Parent (Parent (T))); + if Present (Acc_T) + and then Is_Private_Type (Acc_T) + then + Switch_View (Acc_T); + end if; + end if; + + Copy_Descendants; + end; + + -- For a proper body, we must catch the case of a proper body that + -- replaces a stub. This represents the point at which a separate + -- compilation unit, and hence template file, may be referenced, so we + -- must make a new source instantiation entry for the template of the + -- subunit, and ensure that all nodes in the subunit are adjusted using + -- this new source instantiation entry. + + elsif Nkind (N) in N_Proper_Body then + declare + Save_Adjustment : constant Sloc_Adjustment := S_Adjustment; + + begin + if Instantiating and then Was_Originally_Stub (N) then + Create_Instantiation_Source + (Instantiation_Node, + Defining_Entity (N), + False, + S_Adjustment); + end if; + + -- Now copy the fields of the proper body, using the new + -- adjustment factor if one was needed as per test above. + + Copy_Descendants; + + -- Restore the original adjustment factor in case changed + + S_Adjustment := Save_Adjustment; + end; + + -- Don't copy Ident or Comment pragmas, since the comment belongs to the + -- generic unit, not to the instantiating unit. + + elsif Nkind (N) = N_Pragma and then Instantiating then + declare + Prag_Id : constant Pragma_Id := Get_Pragma_Id (N); + begin + if Prag_Id = Pragma_Ident or else Prag_Id = Pragma_Comment then + New_N := Make_Null_Statement (Sloc (N)); + else + Copy_Descendants; + end if; + end; + + elsif Nkind_In (N, N_Integer_Literal, N_Real_Literal) then + + -- No descendant fields need traversing + + null; + + elsif Nkind (N) = N_String_Literal + and then Present (Etype (N)) + and then Instantiating + then + -- If the string is declared in an outer scope, the string_literal + -- subtype created for it may have the wrong scope. We force the + -- reanalysis of the constant to generate a new itype in the proper + -- context. + + Set_Etype (New_N, Empty); + Set_Analyzed (New_N, False); + + -- For the remaining nodes, copy their descendants recursively + + else + Copy_Descendants; + + if Instantiating and then Nkind (N) = N_Subprogram_Body then + Set_Generic_Parent (Specification (New_N), N); + + -- Should preserve Corresponding_Spec??? (12.3(14)) + end if; + end if; + + return New_N; + end Copy_Generic_Node; + + ---------------------------- + -- Denotes_Formal_Package -- + ---------------------------- + + function Denotes_Formal_Package + (Pack : Entity_Id; + On_Exit : Boolean := False; + Instance : Entity_Id := Empty) return Boolean + is + Par : Entity_Id; + Scop : constant Entity_Id := Scope (Pack); + E : Entity_Id; + + function Is_Actual_Of_Previous_Formal (P : Entity_Id) return Boolean; + -- The package in question may be an actual for a previous formal + -- package P of the current instance, so examine its actuals as well. + -- This must be recursive over other formal packages. + + ---------------------------------- + -- Is_Actual_Of_Previous_Formal -- + ---------------------------------- + + function Is_Actual_Of_Previous_Formal (P : Entity_Id) return Boolean is + E1 : Entity_Id; + + begin + E1 := First_Entity (P); + while Present (E1) and then E1 /= Instance loop + if Ekind (E1) = E_Package + and then Nkind (Parent (E1)) = N_Package_Renaming_Declaration + then + if Renamed_Object (E1) = Pack then + return True; + + elsif E1 = P or else Renamed_Object (E1) = P then + return False; + + elsif Is_Actual_Of_Previous_Formal (E1) then + return True; + end if; + end if; + + Next_Entity (E1); + end loop; + + return False; + end Is_Actual_Of_Previous_Formal; + + -- Start of processing for Denotes_Formal_Package + + begin + if On_Exit then + Par := + Instance_Envs.Table + (Instance_Envs.Last).Instantiated_Parent.Act_Id; + else + Par := Current_Instantiated_Parent.Act_Id; + end if; + + if Ekind (Scop) = E_Generic_Package + or else Nkind (Unit_Declaration_Node (Scop)) = + N_Generic_Subprogram_Declaration + then + return True; + + elsif Nkind (Original_Node (Unit_Declaration_Node (Pack))) = + N_Formal_Package_Declaration + then + return True; + + elsif No (Par) then + return False; + + else + -- Check whether this package is associated with a formal package of + -- the enclosing instantiation. Iterate over the list of renamings. + + E := First_Entity (Par); + while Present (E) loop + if Ekind (E) /= E_Package + or else Nkind (Parent (E)) /= N_Package_Renaming_Declaration + then + null; + + elsif Renamed_Object (E) = Par then + return False; + + elsif Renamed_Object (E) = Pack then + return True; + + elsif Is_Actual_Of_Previous_Formal (E) then + return True; + + end if; + + Next_Entity (E); + end loop; + + return False; + end if; + end Denotes_Formal_Package; + + ----------------- + -- End_Generic -- + ----------------- + + procedure End_Generic is + begin + -- ??? More things could be factored out in this routine. Should + -- probably be done at a later stage. + + Inside_A_Generic := Generic_Flags.Table (Generic_Flags.Last); + Generic_Flags.Decrement_Last; + + Expander_Mode_Restore; + end End_Generic; + + ------------- + -- Earlier -- + ------------- + + function Earlier (N1, N2 : Node_Id) return Boolean is + procedure Find_Depth (P : in out Node_Id; D : in out Integer); + -- Find distance from given node to enclosing compilation unit + + ---------------- + -- Find_Depth -- + ---------------- + + procedure Find_Depth (P : in out Node_Id; D : in out Integer) is + begin + while Present (P) + and then Nkind (P) /= N_Compilation_Unit + loop + P := True_Parent (P); + D := D + 1; + end loop; + end Find_Depth; + + -- Local declarations + + D1 : Integer := 0; + D2 : Integer := 0; + P1 : Node_Id := N1; + P2 : Node_Id := N2; + T1 : Source_Ptr; + T2 : Source_Ptr; + + -- Start of processing for Earlier + + begin + Find_Depth (P1, D1); + Find_Depth (P2, D2); + + if P1 /= P2 then + return False; + else + P1 := N1; + P2 := N2; + end if; + + while D1 > D2 loop + P1 := True_Parent (P1); + D1 := D1 - 1; + end loop; + + while D2 > D1 loop + P2 := True_Parent (P2); + D2 := D2 - 1; + end loop; + + -- At this point P1 and P2 are at the same distance from the root. + -- We examine their parents until we find a common declarative list. + -- If we reach the root, N1 and N2 do not descend from the same + -- declarative list (e.g. one is nested in the declarative part and + -- the other is in a block in the statement part) and the earlier + -- one is already frozen. + + while not Is_List_Member (P1) + or else not Is_List_Member (P2) + or else List_Containing (P1) /= List_Containing (P2) + loop + P1 := True_Parent (P1); + P2 := True_Parent (P2); + + if Nkind (Parent (P1)) = N_Subunit then + P1 := Corresponding_Stub (Parent (P1)); + end if; + + if Nkind (Parent (P2)) = N_Subunit then + P2 := Corresponding_Stub (Parent (P2)); + end if; + + if P1 = P2 then + return False; + end if; + end loop; + + -- Expanded code usually shares the source location of the original + -- construct it was generated for. This however may not necessarely + -- reflect the true location of the code within the tree. + + -- Before comparing the slocs of the two nodes, make sure that we are + -- working with correct source locations. Assume that P1 is to the left + -- of P2. If either one does not come from source, traverse the common + -- list heading towards the other node and locate the first source + -- statement. + + -- P1 P2 + -- ----+===+===+--------------+===+===+---- + -- expanded code expanded code + + if not Comes_From_Source (P1) then + while Present (P1) loop + + -- Neither P2 nor a source statement were located during the + -- search. If we reach the end of the list, then P1 does not + -- occur earlier than P2. + + -- ----> + -- start --- P2 ----- P1 --- end + + if No (Next (P1)) then + return False; + + -- We encounter P2 while going to the right of the list. This + -- means that P1 does indeed appear earlier. + + -- ----> + -- start --- P1 ===== P2 --- end + -- expanded code in between + + elsif P1 = P2 then + return True; + + -- No need to look any further since we have located a source + -- statement. + + elsif Comes_From_Source (P1) then + exit; + end if; + + -- Keep going right + + Next (P1); + end loop; + end if; + + if not Comes_From_Source (P2) then + while Present (P2) loop + + -- Neither P1 nor a source statement were located during the + -- search. If we reach the start of the list, then P1 does not + -- occur earlier than P2. + + -- <---- + -- start --- P2 --- P1 --- end + + if No (Prev (P2)) then + return False; + + -- We encounter P1 while going to the left of the list. This + -- means that P1 does indeed appear earlier. + + -- <---- + -- start --- P1 ===== P2 --- end + -- expanded code in between + + elsif P2 = P1 then + return True; + + -- No need to look any further since we have located a source + -- statement. + + elsif Comes_From_Source (P2) then + exit; + end if; + + -- Keep going left + + Prev (P2); + end loop; + end if; + + -- At this point either both nodes came from source or we approximated + -- their source locations through neighbouring source statements. + + T1 := Top_Level_Location (Sloc (P1)); + T2 := Top_Level_Location (Sloc (P2)); + + -- When two nodes come from the same instance, they have identical top + -- level locations. To determine proper relation within the tree, check + -- their locations within the template. + + if T1 = T2 then + return Sloc (P1) < Sloc (P2); + + -- The two nodes either come from unrelated instances or do not come + -- from instantiated code at all. + + else + return T1 < T2; + end if; + end Earlier; + + ---------------------- + -- Find_Actual_Type -- + ---------------------- + + function Find_Actual_Type + (Typ : Entity_Id; + Gen_Type : Entity_Id) return Entity_Id + is + Gen_Scope : constant Entity_Id := Scope (Gen_Type); + T : Entity_Id; + + begin + -- Special processing only applies to child units + + if not Is_Child_Unit (Gen_Scope) then + return Get_Instance_Of (Typ); + + -- If designated or component type is itself a formal of the child unit, + -- its instance is available. + + elsif Scope (Typ) = Gen_Scope then + return Get_Instance_Of (Typ); + + -- If the array or access type is not declared in the parent unit, + -- no special processing needed. + + elsif not Is_Generic_Type (Typ) + and then Scope (Gen_Scope) /= Scope (Typ) + then + return Get_Instance_Of (Typ); + + -- Otherwise, retrieve designated or component type by visibility + + else + T := Current_Entity (Typ); + while Present (T) loop + if In_Open_Scopes (Scope (T)) then + return T; + + elsif Is_Generic_Actual_Type (T) then + return T; + end if; + + T := Homonym (T); + end loop; + + return Typ; + end if; + end Find_Actual_Type; + + ---------------------------- + -- Freeze_Subprogram_Body -- + ---------------------------- + + procedure Freeze_Subprogram_Body + (Inst_Node : Node_Id; + Gen_Body : Node_Id; + Pack_Id : Entity_Id) + is + Gen_Unit : constant Entity_Id := Get_Generic_Entity (Inst_Node); + Par : constant Entity_Id := Scope (Gen_Unit); + E_G_Id : Entity_Id; + Enc_G : Entity_Id; + Enc_I : Node_Id; + F_Node : Node_Id; + + function Enclosing_Package_Body (N : Node_Id) return Node_Id; + -- Find innermost package body that encloses the given node, and which + -- is not a compilation unit. Freeze nodes for the instance, or for its + -- enclosing body, may be inserted after the enclosing_body of the + -- generic unit. Used to determine proper placement of freeze node for + -- both package and subprogram instances. + + function Package_Freeze_Node (B : Node_Id) return Node_Id; + -- Find entity for given package body, and locate or create a freeze + -- node for it. + + ---------------------------- + -- Enclosing_Package_Body -- + ---------------------------- + + function Enclosing_Package_Body (N : Node_Id) return Node_Id is + P : Node_Id; + + begin + P := Parent (N); + while Present (P) + and then Nkind (Parent (P)) /= N_Compilation_Unit + loop + if Nkind (P) = N_Package_Body then + if Nkind (Parent (P)) = N_Subunit then + return Corresponding_Stub (Parent (P)); + else + return P; + end if; + end if; + + P := True_Parent (P); + end loop; + + return Empty; + end Enclosing_Package_Body; + + ------------------------- + -- Package_Freeze_Node -- + ------------------------- + + function Package_Freeze_Node (B : Node_Id) return Node_Id is + Id : Entity_Id; + + begin + if Nkind (B) = N_Package_Body then + Id := Corresponding_Spec (B); + else pragma Assert (Nkind (B) = N_Package_Body_Stub); + Id := Corresponding_Spec (Proper_Body (Unit (Library_Unit (B)))); + end if; + + Ensure_Freeze_Node (Id); + return Freeze_Node (Id); + end Package_Freeze_Node; + + -- Start of processing of Freeze_Subprogram_Body + + begin + -- If the instance and the generic body appear within the same unit, and + -- the instance precedes the generic, the freeze node for the instance + -- must appear after that of the generic. If the generic is nested + -- within another instance I2, then current instance must be frozen + -- after I2. In both cases, the freeze nodes are those of enclosing + -- packages. Otherwise, the freeze node is placed at the end of the + -- current declarative part. + + Enc_G := Enclosing_Package_Body (Gen_Body); + Enc_I := Enclosing_Package_Body (Inst_Node); + Ensure_Freeze_Node (Pack_Id); + F_Node := Freeze_Node (Pack_Id); + + if Is_Generic_Instance (Par) + and then Present (Freeze_Node (Par)) + and then In_Same_Declarative_Part (Freeze_Node (Par), Inst_Node) + then + -- The parent was a premature instantiation. Insert freeze node at + -- the end the current declarative part. + + if ABE_Is_Certain (Get_Package_Instantiation_Node (Par)) then + Insert_Freeze_Node_For_Instance (Inst_Node, F_Node); + + -- Handle the following case: + -- + -- package Parent_Inst is new ... + -- Parent_Inst [] + -- + -- procedure P ... -- this body freezes Parent_Inst + -- + -- package Inst is new ... + -- + -- In this particular scenario, the freeze node for Inst must be + -- inserted in the same manner as that of Parent_Inst - before the + -- next source body or at the end of the declarative list (body not + -- available). If body P did not exist and Parent_Inst was frozen + -- after Inst, either by a body following Inst or at the end of the + -- declarative region, the freeze node for Inst must be inserted + -- after that of Parent_Inst. This relation is established by + -- comparing the Slocs of Parent_Inst freeze node and Inst. + + elsif List_Containing (Get_Package_Instantiation_Node (Par)) = + List_Containing (Inst_Node) + and then Sloc (Freeze_Node (Par)) < Sloc (Inst_Node) + then + Insert_Freeze_Node_For_Instance (Inst_Node, F_Node); + + else + Insert_After (Freeze_Node (Par), F_Node); + end if; + + -- The body enclosing the instance should be frozen after the body that + -- includes the generic, because the body of the instance may make + -- references to entities therein. If the two are not in the same + -- declarative part, or if the one enclosing the instance is frozen + -- already, freeze the instance at the end of the current declarative + -- part. + + elsif Is_Generic_Instance (Par) + and then Present (Freeze_Node (Par)) + and then Present (Enc_I) + then + if In_Same_Declarative_Part (Freeze_Node (Par), Enc_I) + or else + (Nkind (Enc_I) = N_Package_Body + and then + In_Same_Declarative_Part (Freeze_Node (Par), Parent (Enc_I))) + then + -- The enclosing package may contain several instances. Rather + -- than computing the earliest point at which to insert its freeze + -- node, we place it at the end of the declarative part of the + -- parent of the generic. + + Insert_Freeze_Node_For_Instance + (Freeze_Node (Par), Package_Freeze_Node (Enc_I)); + end if; + + Insert_Freeze_Node_For_Instance (Inst_Node, F_Node); + + elsif Present (Enc_G) + and then Present (Enc_I) + and then Enc_G /= Enc_I + and then Earlier (Inst_Node, Gen_Body) + then + if Nkind (Enc_G) = N_Package_Body then + E_G_Id := Corresponding_Spec (Enc_G); + else pragma Assert (Nkind (Enc_G) = N_Package_Body_Stub); + E_G_Id := + Corresponding_Spec (Proper_Body (Unit (Library_Unit (Enc_G)))); + end if; + + -- Freeze package that encloses instance, and place node after the + -- package that encloses generic. If enclosing package is already + -- frozen we have to assume it is at the proper place. This may be a + -- potential ABE that requires dynamic checking. Do not add a freeze + -- node if the package that encloses the generic is inside the body + -- that encloses the instance, because the freeze node would be in + -- the wrong scope. Additional contortions needed if the bodies are + -- within a subunit. + + declare + Enclosing_Body : Node_Id; + + begin + if Nkind (Enc_I) = N_Package_Body_Stub then + Enclosing_Body := Proper_Body (Unit (Library_Unit (Enc_I))); + else + Enclosing_Body := Enc_I; + end if; + + if Parent (List_Containing (Enc_G)) /= Enclosing_Body then + Insert_Freeze_Node_For_Instance + (Enc_G, Package_Freeze_Node (Enc_I)); + end if; + end; + + -- Freeze enclosing subunit before instance + + Ensure_Freeze_Node (E_G_Id); + + if not Is_List_Member (Freeze_Node (E_G_Id)) then + Insert_After (Enc_G, Freeze_Node (E_G_Id)); + end if; + + Insert_Freeze_Node_For_Instance (Inst_Node, F_Node); + + else + -- If none of the above, insert freeze node at the end of the current + -- declarative part. + + Insert_Freeze_Node_For_Instance (Inst_Node, F_Node); + end if; + end Freeze_Subprogram_Body; + + ---------------- + -- Get_Gen_Id -- + ---------------- + + function Get_Gen_Id (E : Assoc_Ptr) return Entity_Id is + begin + return Generic_Renamings.Table (E).Gen_Id; + end Get_Gen_Id; + + --------------------- + -- Get_Instance_Of -- + --------------------- + + function Get_Instance_Of (A : Entity_Id) return Entity_Id is + Res : constant Assoc_Ptr := Generic_Renamings_HTable.Get (A); + + begin + if Res /= Assoc_Null then + return Generic_Renamings.Table (Res).Act_Id; + else + -- On exit, entity is not instantiated: not a generic parameter, or + -- else parameter of an inner generic unit. + + return A; + end if; + end Get_Instance_Of; + + ------------------------------------ + -- Get_Package_Instantiation_Node -- + ------------------------------------ + + function Get_Package_Instantiation_Node (A : Entity_Id) return Node_Id is + Decl : Node_Id := Unit_Declaration_Node (A); + Inst : Node_Id; + + begin + -- If the Package_Instantiation attribute has been set on the package + -- entity, then use it directly when it (or its Original_Node) refers + -- to an N_Package_Instantiation node. In principle it should be + -- possible to have this field set in all cases, which should be + -- investigated, and would allow this function to be significantly + -- simplified. ??? + + Inst := Package_Instantiation (A); + + if Present (Inst) then + if Nkind (Inst) = N_Package_Instantiation then + return Inst; + + elsif Nkind (Original_Node (Inst)) = N_Package_Instantiation then + return Original_Node (Inst); + end if; + end if; + + -- If the instantiation is a compilation unit that does not need body + -- then the instantiation node has been rewritten as a package + -- declaration for the instance, and we return the original node. + + -- If it is a compilation unit and the instance node has not been + -- rewritten, then it is still the unit of the compilation. Finally, if + -- a body is present, this is a parent of the main unit whose body has + -- been compiled for inlining purposes, and the instantiation node has + -- been rewritten with the instance body. + + -- Otherwise the instantiation node appears after the declaration. If + -- the entity is a formal package, the declaration may have been + -- rewritten as a generic declaration (in the case of a formal with box) + -- or left as a formal package declaration if it has actuals, and is + -- found with a forward search. + + if Nkind (Parent (Decl)) = N_Compilation_Unit then + if Nkind (Decl) = N_Package_Declaration + and then Present (Corresponding_Body (Decl)) + then + Decl := Unit_Declaration_Node (Corresponding_Body (Decl)); + end if; + + if Nkind (Original_Node (Decl)) = N_Package_Instantiation then + return Original_Node (Decl); + else + return Unit (Parent (Decl)); + end if; + + elsif Nkind (Decl) = N_Package_Declaration + and then Nkind (Original_Node (Decl)) = N_Formal_Package_Declaration + then + return Original_Node (Decl); + + else + Inst := Next (Decl); + while not Nkind_In (Inst, N_Package_Instantiation, + N_Formal_Package_Declaration) + loop + Next (Inst); + end loop; + + return Inst; + end if; + end Get_Package_Instantiation_Node; + + ------------------------ + -- Has_Been_Exchanged -- + ------------------------ + + function Has_Been_Exchanged (E : Entity_Id) return Boolean is + Next : Elmt_Id; + + begin + Next := First_Elmt (Exchanged_Views); + while Present (Next) loop + if Full_View (Node (Next)) = E then + return True; + end if; + + Next_Elmt (Next); + end loop; + + return False; + end Has_Been_Exchanged; + + ---------- + -- Hash -- + ---------- + + function Hash (F : Entity_Id) return HTable_Range is + begin + return HTable_Range (F mod HTable_Size); + end Hash; + + ------------------------ + -- Hide_Current_Scope -- + ------------------------ + + procedure Hide_Current_Scope is + C : constant Entity_Id := Current_Scope; + E : Entity_Id; + + begin + Set_Is_Hidden_Open_Scope (C); + + E := First_Entity (C); + while Present (E) loop + if Is_Immediately_Visible (E) then + Set_Is_Immediately_Visible (E, False); + Append_Elmt (E, Hidden_Entities); + end if; + + Next_Entity (E); + end loop; + + -- Make the scope name invisible as well. This is necessary, but might + -- conflict with calls to Rtsfind later on, in case the scope is a + -- predefined one. There is no clean solution to this problem, so for + -- now we depend on the user not redefining Standard itself in one of + -- the parent units. + + if Is_Immediately_Visible (C) and then C /= Standard_Standard then + Set_Is_Immediately_Visible (C, False); + Append_Elmt (C, Hidden_Entities); + end if; + + end Hide_Current_Scope; + + -------------- + -- Init_Env -- + -------------- + + procedure Init_Env is + Saved : Instance_Env; + + begin + Saved.Instantiated_Parent := Current_Instantiated_Parent; + Saved.Exchanged_Views := Exchanged_Views; + Saved.Hidden_Entities := Hidden_Entities; + Saved.Current_Sem_Unit := Current_Sem_Unit; + Saved.Parent_Unit_Visible := Parent_Unit_Visible; + Saved.Instance_Parent_Unit := Instance_Parent_Unit; + + -- Save configuration switches. These may be reset if the unit is a + -- predefined unit, and the current mode is not Ada 2005. + + Save_Opt_Config_Switches (Saved.Switches); + + Instance_Envs.Append (Saved); + + Exchanged_Views := New_Elmt_List; + Hidden_Entities := New_Elmt_List; + + -- Make dummy entry for Instantiated parent. If generic unit is legal, + -- this is set properly in Set_Instance_Env. + + Current_Instantiated_Parent := + (Current_Scope, Current_Scope, Assoc_Null); + end Init_Env; + + ------------------------------ + -- In_Same_Declarative_Part -- + ------------------------------ + + function In_Same_Declarative_Part + (F_Node : Node_Id; + Inst : Node_Id) return Boolean + is + Decls : constant Node_Id := Parent (F_Node); + Nod : Node_Id := Parent (Inst); + + begin + while Present (Nod) loop + if Nod = Decls then + return True; + + elsif Nkind_In (Nod, N_Subprogram_Body, + N_Package_Body, + N_Package_Declaration, + N_Task_Body, + N_Protected_Body, + N_Block_Statement) + then + return False; + + elsif Nkind (Nod) = N_Subunit then + Nod := Corresponding_Stub (Nod); + + elsif Nkind (Nod) = N_Compilation_Unit then + return False; + + else + Nod := Parent (Nod); + end if; + end loop; + + return False; + end In_Same_Declarative_Part; + + --------------------- + -- In_Main_Context -- + --------------------- + + function In_Main_Context (E : Entity_Id) return Boolean is + Context : List_Id; + Clause : Node_Id; + Nam : Node_Id; + + begin + if not Is_Compilation_Unit (E) + or else Ekind (E) /= E_Package + or else In_Private_Part (E) + then + return False; + end if; + + Context := Context_Items (Cunit (Main_Unit)); + + Clause := First (Context); + while Present (Clause) loop + if Nkind (Clause) = N_With_Clause then + Nam := Name (Clause); + + -- If the current scope is part of the context of the main unit, + -- analysis of the corresponding with_clause is not complete, and + -- the entity is not set. We use the Chars field directly, which + -- might produce false positives in rare cases, but guarantees + -- that we produce all the instance bodies we will need. + + if (Is_Entity_Name (Nam) and then Chars (Nam) = Chars (E)) + or else (Nkind (Nam) = N_Selected_Component + and then Chars (Selector_Name (Nam)) = Chars (E)) + then + return True; + end if; + end if; + + Next (Clause); + end loop; + + return False; + end In_Main_Context; + + --------------------- + -- Inherit_Context -- + --------------------- + + procedure Inherit_Context (Gen_Decl : Node_Id; Inst : Node_Id) is + Current_Context : List_Id; + Current_Unit : Node_Id; + Item : Node_Id; + New_I : Node_Id; + + Clause : Node_Id; + OK : Boolean; + Lib_Unit : Node_Id; + + begin + if Nkind (Parent (Gen_Decl)) = N_Compilation_Unit then + + -- The inherited context is attached to the enclosing compilation + -- unit. This is either the main unit, or the declaration for the + -- main unit (in case the instantiation appears within the package + -- declaration and the main unit is its body). + + Current_Unit := Parent (Inst); + while Present (Current_Unit) + and then Nkind (Current_Unit) /= N_Compilation_Unit + loop + Current_Unit := Parent (Current_Unit); + end loop; + + Current_Context := Context_Items (Current_Unit); + + Item := First (Context_Items (Parent (Gen_Decl))); + while Present (Item) loop + if Nkind (Item) = N_With_Clause then + Lib_Unit := Library_Unit (Item); + + -- Take care to prevent direct cyclic with's + + if Lib_Unit /= Current_Unit then + + -- Do not add a unit if it is already in the context + + Clause := First (Current_Context); + OK := True; + while Present (Clause) loop + if Nkind (Clause) = N_With_Clause and then + Library_Unit (Clause) = Lib_Unit + then + OK := False; + exit; + end if; + + Next (Clause); + end loop; + + if OK then + New_I := New_Copy (Item); + Set_Implicit_With (New_I, True); + Set_Implicit_With_From_Instantiation (New_I, True); + Append (New_I, Current_Context); + end if; + end if; + end if; + + Next (Item); + end loop; + end if; + end Inherit_Context; + + ---------------- + -- Initialize -- + ---------------- + + procedure Initialize is + begin + Generic_Renamings.Init; + Instance_Envs.Init; + Generic_Flags.Init; + Generic_Renamings_HTable.Reset; + Circularity_Detected := False; + Exchanged_Views := No_Elist; + Hidden_Entities := No_Elist; + end Initialize; + + ------------------------------------- + -- Insert_Freeze_Node_For_Instance -- + ------------------------------------- + + procedure Insert_Freeze_Node_For_Instance + (N : Node_Id; + F_Node : Node_Id) + is + Decl : Node_Id; + Decls : List_Id; + Inst : Entity_Id; + Par_N : Node_Id; + + function Enclosing_Body (N : Node_Id) return Node_Id; + -- Find enclosing package or subprogram body, if any. Freeze node may + -- be placed at end of current declarative list if previous instance + -- and current one have different enclosing bodies. + + function Previous_Instance (Gen : Entity_Id) return Entity_Id; + -- Find the local instance, if any, that declares the generic that is + -- being instantiated. If present, the freeze node for this instance + -- must follow the freeze node for the previous instance. + + -------------------- + -- Enclosing_Body -- + -------------------- + + function Enclosing_Body (N : Node_Id) return Node_Id is + P : Node_Id; + + begin + P := Parent (N); + while Present (P) + and then Nkind (Parent (P)) /= N_Compilation_Unit + loop + if Nkind_In (P, N_Package_Body, N_Subprogram_Body) then + if Nkind (Parent (P)) = N_Subunit then + return Corresponding_Stub (Parent (P)); + else + return P; + end if; + end if; + + P := True_Parent (P); + end loop; + + return Empty; + end Enclosing_Body; + + ----------------------- + -- Previous_Instance -- + ----------------------- + + function Previous_Instance (Gen : Entity_Id) return Entity_Id is + S : Entity_Id; + + begin + S := Scope (Gen); + while Present (S) + and then S /= Standard_Standard + loop + if Is_Generic_Instance (S) + and then In_Same_Source_Unit (S, N) + then + return S; + end if; + + S := Scope (S); + end loop; + + return Empty; + end Previous_Instance; + + -- Start of processing for Insert_Freeze_Node_For_Instance + + begin + if not Is_List_Member (F_Node) then + Decl := N; + Decls := List_Containing (N); + Inst := Entity (F_Node); + Par_N := Parent (Decls); + + -- When processing a subprogram instantiation, utilize the actual + -- subprogram instantiation rather than its package wrapper as it + -- carries all the context information. + + if Is_Wrapper_Package (Inst) then + Inst := Related_Instance (Inst); + end if; + + -- If this is a package instance, check whether the generic is + -- declared in a previous instance and the current instance is + -- not within the previous one. + + if Present (Generic_Parent (Parent (Inst))) + and then Is_In_Main_Unit (N) + then + declare + Enclosing_N : constant Node_Id := Enclosing_Body (N); + Par_I : constant Entity_Id := + Previous_Instance + (Generic_Parent (Parent (Inst))); + Scop : Entity_Id; + + begin + if Present (Par_I) + and then Earlier (N, Freeze_Node (Par_I)) + then + Scop := Scope (Inst); + + -- If the current instance is within the one that contains + -- the generic, the freeze node for the current one must + -- appear in the current declarative part. Ditto, if the + -- current instance is within another package instance or + -- within a body that does not enclose the current instance. + -- In these three cases the freeze node of the previous + -- instance is not relevant. + + while Present (Scop) + and then Scop /= Standard_Standard + loop + exit when Scop = Par_I + or else + (Is_Generic_Instance (Scop) + and then Scope_Depth (Scop) > Scope_Depth (Par_I)); + Scop := Scope (Scop); + end loop; + + -- Previous instance encloses current instance + + if Scop = Par_I then + null; + + -- If the next node is a source body we must freeze in + -- the current scope as well. + + elsif Present (Next (N)) + and then Nkind_In (Next (N), + N_Subprogram_Body, N_Package_Body) + and then Comes_From_Source (Next (N)) + then + null; + + -- Current instance is within an unrelated instance + + elsif Is_Generic_Instance (Scop) then + null; + + -- Current instance is within an unrelated body + + elsif Present (Enclosing_N) + and then Enclosing_N /= Enclosing_Body (Par_I) + then + null; + + else + Insert_After (Freeze_Node (Par_I), F_Node); + return; + end if; + end if; + end; + end if; + + -- When the instantiation occurs in a package declaration, append the + -- freeze node to the private declarations (if any). + + if Nkind (Par_N) = N_Package_Specification + and then Decls = Visible_Declarations (Par_N) + and then Present (Private_Declarations (Par_N)) + and then not Is_Empty_List (Private_Declarations (Par_N)) + then + Decls := Private_Declarations (Par_N); + Decl := First (Decls); + end if; + + -- Determine the proper freeze point of a package instantiation. We + -- adhere to the general rule of a package or subprogram body causing + -- freezing of anything before it in the same declarative region. In + -- this case, the proper freeze point of a package instantiation is + -- before the first source body which follows, or before a stub. This + -- ensures that entities coming from the instance are already frozen + -- and usable in source bodies. + + if Nkind (Par_N) /= N_Package_Declaration + and then Ekind (Inst) = E_Package + and then Is_Generic_Instance (Inst) + and then + not In_Same_Source_Unit (Generic_Parent (Parent (Inst)), Inst) + then + while Present (Decl) loop + if (Nkind (Decl) in N_Unit_Body + or else + Nkind (Decl) in N_Body_Stub) + and then Comes_From_Source (Decl) + then + Insert_Before (Decl, F_Node); + return; + end if; + + Next (Decl); + end loop; + end if; + + -- In a package declaration, or if no previous body, insert at end + -- of list. + + Set_Sloc (F_Node, Sloc (Last (Decls))); + Insert_After (Last (Decls), F_Node); + end if; + end Insert_Freeze_Node_For_Instance; + + ------------------ + -- Install_Body -- + ------------------ + + procedure Install_Body + (Act_Body : Node_Id; + N : Node_Id; + Gen_Body : Node_Id; + Gen_Decl : Node_Id) + is + Act_Id : constant Entity_Id := Corresponding_Spec (Act_Body); + Act_Unit : constant Node_Id := Unit (Cunit (Get_Source_Unit (N))); + Gen_Id : constant Entity_Id := Corresponding_Spec (Gen_Body); + Par : constant Entity_Id := Scope (Gen_Id); + Gen_Unit : constant Node_Id := + Unit (Cunit (Get_Source_Unit (Gen_Decl))); + Orig_Body : Node_Id := Gen_Body; + F_Node : Node_Id; + Body_Unit : Node_Id; + + Must_Delay : Boolean; + + function Enclosing_Subp (Id : Entity_Id) return Entity_Id; + -- Find subprogram (if any) that encloses instance and/or generic body + + function True_Sloc (N : Node_Id) return Source_Ptr; + -- If the instance is nested inside a generic unit, the Sloc of the + -- instance indicates the place of the original definition, not the + -- point of the current enclosing instance. Pending a better usage of + -- Slocs to indicate instantiation places, we determine the place of + -- origin of a node by finding the maximum sloc of any ancestor node. + -- Why is this not equivalent to Top_Level_Location ??? + + -------------------- + -- Enclosing_Subp -- + -------------------- + + function Enclosing_Subp (Id : Entity_Id) return Entity_Id is + Scop : Entity_Id; + + begin + Scop := Scope (Id); + while Scop /= Standard_Standard + and then not Is_Overloadable (Scop) + loop + Scop := Scope (Scop); + end loop; + + return Scop; + end Enclosing_Subp; + + --------------- + -- True_Sloc -- + --------------- + + function True_Sloc (N : Node_Id) return Source_Ptr is + Res : Source_Ptr; + N1 : Node_Id; + + begin + Res := Sloc (N); + N1 := N; + while Present (N1) and then N1 /= Act_Unit loop + if Sloc (N1) > Res then + Res := Sloc (N1); + end if; + + N1 := Parent (N1); + end loop; + + return Res; + end True_Sloc; + + -- Start of processing for Install_Body + + begin + -- If the body is a subunit, the freeze point is the corresponding stub + -- in the current compilation, not the subunit itself. + + if Nkind (Parent (Gen_Body)) = N_Subunit then + Orig_Body := Corresponding_Stub (Parent (Gen_Body)); + else + Orig_Body := Gen_Body; + end if; + + Body_Unit := Unit (Cunit (Get_Source_Unit (Orig_Body))); + + -- If the instantiation and the generic definition appear in the same + -- package declaration, this is an early instantiation. If they appear + -- in the same declarative part, it is an early instantiation only if + -- the generic body appears textually later, and the generic body is + -- also in the main unit. + + -- If instance is nested within a subprogram, and the generic body is + -- not, the instance is delayed because the enclosing body is. If + -- instance and body are within the same scope, or the same sub- + -- program body, indicate explicitly that the instance is delayed. + + Must_Delay := + (Gen_Unit = Act_Unit + and then (Nkind_In (Gen_Unit, N_Package_Declaration, + N_Generic_Package_Declaration) + or else (Gen_Unit = Body_Unit + and then True_Sloc (N) < Sloc (Orig_Body))) + and then Is_In_Main_Unit (Gen_Unit) + and then (Scope (Act_Id) = Scope (Gen_Id) + or else + Enclosing_Subp (Act_Id) = Enclosing_Subp (Gen_Id))); + + -- If this is an early instantiation, the freeze node is placed after + -- the generic body. Otherwise, if the generic appears in an instance, + -- we cannot freeze the current instance until the outer one is frozen. + -- This is only relevant if the current instance is nested within some + -- inner scope not itself within the outer instance. If this scope is + -- a package body in the same declarative part as the outer instance, + -- then that body needs to be frozen after the outer instance. Finally, + -- if no delay is needed, we place the freeze node at the end of the + -- current declarative part. + + if Expander_Active then + Ensure_Freeze_Node (Act_Id); + F_Node := Freeze_Node (Act_Id); + + if Must_Delay then + Insert_After (Orig_Body, F_Node); + + elsif Is_Generic_Instance (Par) + and then Present (Freeze_Node (Par)) + and then Scope (Act_Id) /= Par + then + -- Freeze instance of inner generic after instance of enclosing + -- generic. + + if In_Same_Declarative_Part (Freeze_Node (Par), N) then + + -- Handle the following case: + + -- package Parent_Inst is new ... + -- Parent_Inst [] + + -- procedure P ... -- this body freezes Parent_Inst + + -- package Inst is new ... + + -- In this particular scenario, the freeze node for Inst must + -- be inserted in the same manner as that of Parent_Inst - + -- before the next source body or at the end of the declarative + -- list (body not available). If body P did not exist and + -- Parent_Inst was frozen after Inst, either by a body + -- following Inst or at the end of the declarative region, the + -- freeze node for Inst must be inserted after that of + -- Parent_Inst. This relation is established by comparing the + -- Slocs of Parent_Inst freeze node and Inst. + + if List_Containing (Get_Package_Instantiation_Node (Par)) = + List_Containing (N) + and then Sloc (Freeze_Node (Par)) < Sloc (N) + then + Insert_Freeze_Node_For_Instance (N, F_Node); + else + Insert_After (Freeze_Node (Par), F_Node); + end if; + + -- Freeze package enclosing instance of inner generic after + -- instance of enclosing generic. + + elsif Nkind_In (Parent (N), N_Package_Body, N_Subprogram_Body) + and then In_Same_Declarative_Part (Freeze_Node (Par), Parent (N)) + then + declare + Enclosing : Entity_Id; + + begin + Enclosing := Corresponding_Spec (Parent (N)); + + if No (Enclosing) then + Enclosing := Defining_Entity (Parent (N)); + end if; + + Insert_Freeze_Node_For_Instance (N, F_Node); + Ensure_Freeze_Node (Enclosing); + + if not Is_List_Member (Freeze_Node (Enclosing)) then + + -- The enclosing context is a subunit, insert the freeze + -- node after the stub. + + if Nkind (Parent (Parent (N))) = N_Subunit then + Insert_Freeze_Node_For_Instance + (Corresponding_Stub (Parent (Parent (N))), + Freeze_Node (Enclosing)); + + -- The enclosing context is a package with a stub body + -- which has already been replaced by the real body. + -- Insert the freeze node after the actual body. + + elsif Ekind (Enclosing) = E_Package + and then Present (Body_Entity (Enclosing)) + and then Was_Originally_Stub + (Parent (Body_Entity (Enclosing))) + then + Insert_Freeze_Node_For_Instance + (Parent (Body_Entity (Enclosing)), + Freeze_Node (Enclosing)); + + -- The parent instance has been frozen before the body of + -- the enclosing package, insert the freeze node after + -- the body. + + elsif List_Containing (Freeze_Node (Par)) = + List_Containing (Parent (N)) + and then Sloc (Freeze_Node (Par)) < Sloc (Parent (N)) + then + Insert_Freeze_Node_For_Instance + (Parent (N), Freeze_Node (Enclosing)); + + else + Insert_After + (Freeze_Node (Par), Freeze_Node (Enclosing)); + end if; + end if; + end; + + else + Insert_Freeze_Node_For_Instance (N, F_Node); + end if; + + else + Insert_Freeze_Node_For_Instance (N, F_Node); + end if; + end if; + + Set_Is_Frozen (Act_Id); + Insert_Before (N, Act_Body); + Mark_Rewrite_Insertion (Act_Body); + end Install_Body; + + ----------------------------- + -- Install_Formal_Packages -- + ----------------------------- + + procedure Install_Formal_Packages (Par : Entity_Id) is + E : Entity_Id; + Gen : Entity_Id; + Gen_E : Entity_Id := Empty; + + begin + E := First_Entity (Par); + + -- If we are installing an instance parent, locate the formal packages + -- of its generic parent. + + if Is_Generic_Instance (Par) then + Gen := Generic_Parent (Package_Specification (Par)); + Gen_E := First_Entity (Gen); + end if; + + while Present (E) loop + if Ekind (E) = E_Package + and then Nkind (Parent (E)) = N_Package_Renaming_Declaration + then + -- If this is the renaming for the parent instance, done + + if Renamed_Object (E) = Par then + exit; + + -- The visibility of a formal of an enclosing generic is already + -- correct. + + elsif Denotes_Formal_Package (E) then + null; + + elsif Present (Associated_Formal_Package (E)) then + Check_Generic_Actuals (Renamed_Object (E), True); + Set_Is_Hidden (E, False); + + -- Find formal package in generic unit that corresponds to + -- (instance of) formal package in instance. + + while Present (Gen_E) and then Chars (Gen_E) /= Chars (E) loop + Next_Entity (Gen_E); + end loop; + + if Present (Gen_E) then + Map_Formal_Package_Entities (Gen_E, E); + end if; + end if; + end if; + + Next_Entity (E); + if Present (Gen_E) then + Next_Entity (Gen_E); + end if; + end loop; + end Install_Formal_Packages; + + -------------------- + -- Install_Parent -- + -------------------- + + procedure Install_Parent (P : Entity_Id; In_Body : Boolean := False) is + Ancestors : constant Elist_Id := New_Elmt_List; + S : constant Entity_Id := Current_Scope; + Inst_Par : Entity_Id; + First_Par : Entity_Id; + Inst_Node : Node_Id; + Gen_Par : Entity_Id; + First_Gen : Entity_Id; + Elmt : Elmt_Id; + + procedure Install_Noninstance_Specs (Par : Entity_Id); + -- Install the scopes of noninstance parent units ending with Par + + procedure Install_Spec (Par : Entity_Id); + -- The child unit is within the declarative part of the parent, so the + -- declarations within the parent are immediately visible. + + ------------------------------- + -- Install_Noninstance_Specs -- + ------------------------------- + + procedure Install_Noninstance_Specs (Par : Entity_Id) is + begin + if Present (Par) + and then Par /= Standard_Standard + and then not In_Open_Scopes (Par) + then + Install_Noninstance_Specs (Scope (Par)); + Install_Spec (Par); + end if; + end Install_Noninstance_Specs; + + ------------------ + -- Install_Spec -- + ------------------ + + procedure Install_Spec (Par : Entity_Id) is + Spec : constant Node_Id := Package_Specification (Par); + + begin + -- If this parent of the child instance is a top-level unit, + -- then record the unit and its visibility for later resetting in + -- Remove_Parent. We exclude units that are generic instances, as we + -- only want to record this information for the ultimate top-level + -- noninstance parent (is that always correct???). + + if Scope (Par) = Standard_Standard + and then not Is_Generic_Instance (Par) + then + Parent_Unit_Visible := Is_Immediately_Visible (Par); + Instance_Parent_Unit := Par; + end if; + + -- Open the parent scope and make it and its declarations visible. + -- If this point is not within a body, then only the visible + -- declarations should be made visible, and installation of the + -- private declarations is deferred until the appropriate point + -- within analysis of the spec being instantiated (see the handling + -- of parent visibility in Analyze_Package_Specification). This is + -- relaxed in the case where the parent unit is Ada.Tags, to avoid + -- private view problems that occur when compiling instantiations of + -- a generic child of that package (Generic_Dispatching_Constructor). + -- If the instance freezes a tagged type, inlinings of operations + -- from Ada.Tags may need the full view of type Tag. If inlining took + -- proper account of establishing visibility of inlined subprograms' + -- parents then it should be possible to remove this + -- special check. ??? + + Push_Scope (Par); + Set_Is_Immediately_Visible (Par); + Install_Visible_Declarations (Par); + Set_Use (Visible_Declarations (Spec)); + + if In_Body or else Is_RTU (Par, Ada_Tags) then + Install_Private_Declarations (Par); + Set_Use (Private_Declarations (Spec)); + end if; + end Install_Spec; + + -- Start of processing for Install_Parent + + begin + -- We need to install the parent instance to compile the instantiation + -- of the child, but the child instance must appear in the current + -- scope. Given that we cannot place the parent above the current scope + -- in the scope stack, we duplicate the current scope and unstack both + -- after the instantiation is complete. + + -- If the parent is itself the instantiation of a child unit, we must + -- also stack the instantiation of its parent, and so on. Each such + -- ancestor is the prefix of the name in a prior instantiation. + + -- If this is a nested instance, the parent unit itself resolves to + -- a renaming of the parent instance, whose declaration we need. + + -- Finally, the parent may be a generic (not an instance) when the + -- child unit appears as a formal package. + + Inst_Par := P; + + if Present (Renamed_Entity (Inst_Par)) then + Inst_Par := Renamed_Entity (Inst_Par); + end if; + + First_Par := Inst_Par; + + Gen_Par := Generic_Parent (Package_Specification (Inst_Par)); + + First_Gen := Gen_Par; + + while Present (Gen_Par) + and then Is_Child_Unit (Gen_Par) + loop + -- Load grandparent instance as well + + Inst_Node := Get_Package_Instantiation_Node (Inst_Par); + + if Nkind (Name (Inst_Node)) = N_Expanded_Name then + Inst_Par := Entity (Prefix (Name (Inst_Node))); + + if Present (Renamed_Entity (Inst_Par)) then + Inst_Par := Renamed_Entity (Inst_Par); + end if; + + Gen_Par := Generic_Parent (Package_Specification (Inst_Par)); + + if Present (Gen_Par) then + Prepend_Elmt (Inst_Par, Ancestors); + + else + -- Parent is not the name of an instantiation + + Install_Noninstance_Specs (Inst_Par); + exit; + end if; + + else + -- Previous error + + exit; + end if; + end loop; + + if Present (First_Gen) then + Append_Elmt (First_Par, Ancestors); + else + Install_Noninstance_Specs (First_Par); + end if; + + if not Is_Empty_Elmt_List (Ancestors) then + Elmt := First_Elmt (Ancestors); + while Present (Elmt) loop + Install_Spec (Node (Elmt)); + Install_Formal_Packages (Node (Elmt)); + Next_Elmt (Elmt); + end loop; + end if; + + if not In_Body then + Push_Scope (S); + end if; + end Install_Parent; + + ------------------------------- + -- Install_Hidden_Primitives -- + ------------------------------- + + procedure Install_Hidden_Primitives + (Prims_List : in out Elist_Id; + Gen_T : Entity_Id; + Act_T : Entity_Id) + is + Elmt : Elmt_Id; + List : Elist_Id := No_Elist; + Prim_G_Elmt : Elmt_Id; + Prim_A_Elmt : Elmt_Id; + Prim_G : Node_Id; + Prim_A : Node_Id; + + begin + -- No action needed in case of serious errors because we cannot trust + -- in the order of primitives + + if Serious_Errors_Detected > 0 then + return; + + -- No action possible if we don't have available the list of primitive + -- operations + + elsif No (Gen_T) + or else not Is_Record_Type (Gen_T) + or else not Is_Tagged_Type (Gen_T) + or else not Is_Record_Type (Act_T) + or else not Is_Tagged_Type (Act_T) + then + return; + + -- There is no need to handle interface types since their primitives + -- cannot be hidden + + elsif Is_Interface (Gen_T) then + return; + end if; + + Prim_G_Elmt := First_Elmt (Primitive_Operations (Gen_T)); + + if not Is_Class_Wide_Type (Act_T) then + Prim_A_Elmt := First_Elmt (Primitive_Operations (Act_T)); + else + Prim_A_Elmt := First_Elmt (Primitive_Operations (Root_Type (Act_T))); + end if; + + loop + -- Skip predefined primitives in the generic formal + + while Present (Prim_G_Elmt) + and then Is_Predefined_Dispatching_Operation (Node (Prim_G_Elmt)) + loop + Next_Elmt (Prim_G_Elmt); + end loop; + + -- Skip predefined primitives in the generic actual + + while Present (Prim_A_Elmt) + and then Is_Predefined_Dispatching_Operation (Node (Prim_A_Elmt)) + loop + Next_Elmt (Prim_A_Elmt); + end loop; + + exit when No (Prim_G_Elmt) or else No (Prim_A_Elmt); + + Prim_G := Node (Prim_G_Elmt); + Prim_A := Node (Prim_A_Elmt); + + -- There is no need to handle interface primitives because their + -- primitives are not hidden + + exit when Present (Interface_Alias (Prim_G)); + + -- Here we install one hidden primitive + + if Chars (Prim_G) /= Chars (Prim_A) + and then Has_Suffix (Prim_A, 'P') + and then Remove_Suffix (Prim_A, 'P') = Chars (Prim_G) + then + Set_Chars (Prim_A, Chars (Prim_G)); + + if List = No_Elist then + List := New_Elmt_List; + end if; + + Append_Elmt (Prim_A, List); + end if; + + Next_Elmt (Prim_A_Elmt); + Next_Elmt (Prim_G_Elmt); + end loop; + + -- Append the elements to the list of temporarily visible primitives + -- avoiding duplicates. + + if Present (List) then + if No (Prims_List) then + Prims_List := New_Elmt_List; + end if; + + Elmt := First_Elmt (List); + while Present (Elmt) loop + Append_Unique_Elmt (Node (Elmt), Prims_List); + Next_Elmt (Elmt); + end loop; + end if; + end Install_Hidden_Primitives; + + ------------------------------- + -- Restore_Hidden_Primitives -- + ------------------------------- + + procedure Restore_Hidden_Primitives (Prims_List : in out Elist_Id) is + Prim_Elmt : Elmt_Id; + Prim : Node_Id; + + begin + if Prims_List /= No_Elist then + Prim_Elmt := First_Elmt (Prims_List); + while Present (Prim_Elmt) loop + Prim := Node (Prim_Elmt); + Set_Chars (Prim, Add_Suffix (Prim, 'P')); + Next_Elmt (Prim_Elmt); + end loop; + + Prims_List := No_Elist; + end if; + end Restore_Hidden_Primitives; + + -------------------------------- + -- Instantiate_Formal_Package -- + -------------------------------- + + function Instantiate_Formal_Package + (Formal : Node_Id; + Actual : Node_Id; + Analyzed_Formal : Node_Id) return List_Id + is + Loc : constant Source_Ptr := Sloc (Actual); + Actual_Pack : Entity_Id; + Formal_Pack : Entity_Id; + Gen_Parent : Entity_Id; + Decls : List_Id; + Nod : Node_Id; + Parent_Spec : Node_Id; + + procedure Find_Matching_Actual + (F : Node_Id; + Act : in out Entity_Id); + -- We need to associate each formal entity in the formal package with + -- the corresponding entity in the actual package. The actual package + -- has been analyzed and possibly expanded, and as a result there is + -- no one-to-one correspondence between the two lists (for example, + -- the actual may include subtypes, itypes, and inherited primitive + -- operations, interspersed among the renaming declarations for the + -- actuals) . We retrieve the corresponding actual by name because each + -- actual has the same name as the formal, and they do appear in the + -- same order. + + function Get_Formal_Entity (N : Node_Id) return Entity_Id; + -- Retrieve entity of defining entity of generic formal parameter. + -- Only the declarations of formals need to be considered when + -- linking them to actuals, but the declarative list may include + -- internal entities generated during analysis, and those are ignored. + + procedure Match_Formal_Entity + (Formal_Node : Node_Id; + Formal_Ent : Entity_Id; + Actual_Ent : Entity_Id); + -- Associates the formal entity with the actual. In the case where + -- Formal_Ent is a formal package, this procedure iterates through all + -- of its formals and enters associations between the actuals occurring + -- in the formal package's corresponding actual package (given by + -- Actual_Ent) and the formal package's formal parameters. This + -- procedure recurses if any of the parameters is itself a package. + + function Is_Instance_Of + (Act_Spec : Entity_Id; + Gen_Anc : Entity_Id) return Boolean; + -- The actual can be an instantiation of a generic within another + -- instance, in which case there is no direct link from it to the + -- original generic ancestor. In that case, we recognize that the + -- ultimate ancestor is the same by examining names and scopes. + + procedure Process_Nested_Formal (Formal : Entity_Id); + -- If the current formal is declared with a box, its own formals are + -- visible in the instance, as they were in the generic, and their + -- Hidden flag must be reset. If some of these formals are themselves + -- packages declared with a box, the processing must be recursive. + + -------------------------- + -- Find_Matching_Actual -- + -------------------------- + + procedure Find_Matching_Actual + (F : Node_Id; + Act : in out Entity_Id) + is + Formal_Ent : Entity_Id; + + begin + case Nkind (Original_Node (F)) is + when N_Formal_Object_Declaration | + N_Formal_Type_Declaration => + Formal_Ent := Defining_Identifier (F); + + while Chars (Act) /= Chars (Formal_Ent) loop + Next_Entity (Act); + end loop; + + when N_Formal_Subprogram_Declaration | + N_Formal_Package_Declaration | + N_Package_Declaration | + N_Generic_Package_Declaration => + Formal_Ent := Defining_Entity (F); + + while Chars (Act) /= Chars (Formal_Ent) loop + Next_Entity (Act); + end loop; + + when others => + raise Program_Error; + end case; + end Find_Matching_Actual; + + ------------------------- + -- Match_Formal_Entity -- + ------------------------- + + procedure Match_Formal_Entity + (Formal_Node : Node_Id; + Formal_Ent : Entity_Id; + Actual_Ent : Entity_Id) + is + Act_Pkg : Entity_Id; + + begin + Set_Instance_Of (Formal_Ent, Actual_Ent); + + if Ekind (Actual_Ent) = E_Package then + + -- Record associations for each parameter + + Act_Pkg := Actual_Ent; + + declare + A_Ent : Entity_Id := First_Entity (Act_Pkg); + F_Ent : Entity_Id; + F_Node : Node_Id; + + Gen_Decl : Node_Id; + Formals : List_Id; + Actual : Entity_Id; + + begin + -- Retrieve the actual given in the formal package declaration + + Actual := Entity (Name (Original_Node (Formal_Node))); + + -- The actual in the formal package declaration may be a + -- renamed generic package, in which case we want to retrieve + -- the original generic in order to traverse its formal part. + + if Present (Renamed_Entity (Actual)) then + Gen_Decl := Unit_Declaration_Node (Renamed_Entity (Actual)); + else + Gen_Decl := Unit_Declaration_Node (Actual); + end if; + + Formals := Generic_Formal_Declarations (Gen_Decl); + + if Present (Formals) then + F_Node := First_Non_Pragma (Formals); + else + F_Node := Empty; + end if; + + while Present (A_Ent) + and then Present (F_Node) + and then A_Ent /= First_Private_Entity (Act_Pkg) + loop + F_Ent := Get_Formal_Entity (F_Node); + + if Present (F_Ent) then + + -- This is a formal of the original package. Record + -- association and recurse. + + Find_Matching_Actual (F_Node, A_Ent); + Match_Formal_Entity (F_Node, F_Ent, A_Ent); + Next_Entity (A_Ent); + end if; + + Next_Non_Pragma (F_Node); + end loop; + end; + end if; + end Match_Formal_Entity; + + ----------------------- + -- Get_Formal_Entity -- + ----------------------- + + function Get_Formal_Entity (N : Node_Id) return Entity_Id is + Kind : constant Node_Kind := Nkind (Original_Node (N)); + begin + case Kind is + when N_Formal_Object_Declaration => + return Defining_Identifier (N); + + when N_Formal_Type_Declaration => + return Defining_Identifier (N); + + when N_Formal_Subprogram_Declaration => + return Defining_Unit_Name (Specification (N)); + + when N_Formal_Package_Declaration => + return Defining_Identifier (Original_Node (N)); + + when N_Generic_Package_Declaration => + return Defining_Identifier (Original_Node (N)); + + -- All other declarations are introduced by semantic analysis and + -- have no match in the actual. + + when others => + return Empty; + end case; + end Get_Formal_Entity; + + -------------------- + -- Is_Instance_Of -- + -------------------- + + function Is_Instance_Of + (Act_Spec : Entity_Id; + Gen_Anc : Entity_Id) return Boolean + is + Gen_Par : constant Entity_Id := Generic_Parent (Act_Spec); + + begin + if No (Gen_Par) then + return False; + + -- Simplest case: the generic parent of the actual is the formal + + elsif Gen_Par = Gen_Anc then + return True; + + elsif Chars (Gen_Par) /= Chars (Gen_Anc) then + return False; + + -- The actual may be obtained through several instantiations. Its + -- scope must itself be an instance of a generic declared in the + -- same scope as the formal. Any other case is detected above. + + elsif not Is_Generic_Instance (Scope (Gen_Par)) then + return False; + + else + return Generic_Parent (Parent (Scope (Gen_Par))) = Scope (Gen_Anc); + end if; + end Is_Instance_Of; + + --------------------------- + -- Process_Nested_Formal -- + --------------------------- + + procedure Process_Nested_Formal (Formal : Entity_Id) is + Ent : Entity_Id; + + begin + if Present (Associated_Formal_Package (Formal)) + and then Box_Present (Parent (Associated_Formal_Package (Formal))) + then + Ent := First_Entity (Formal); + while Present (Ent) loop + Set_Is_Hidden (Ent, False); + Set_Is_Visible_Formal (Ent); + Set_Is_Potentially_Use_Visible + (Ent, Is_Potentially_Use_Visible (Formal)); + + if Ekind (Ent) = E_Package then + exit when Renamed_Entity (Ent) = Renamed_Entity (Formal); + Process_Nested_Formal (Ent); + end if; + + Next_Entity (Ent); + end loop; + end if; + end Process_Nested_Formal; + + -- Start of processing for Instantiate_Formal_Package + + begin + Analyze (Actual); + + if not Is_Entity_Name (Actual) + or else Ekind (Entity (Actual)) /= E_Package + then + Error_Msg_N + ("expect package instance to instantiate formal", Actual); + Abandon_Instantiation (Actual); + raise Program_Error; + + else + Actual_Pack := Entity (Actual); + Set_Is_Instantiated (Actual_Pack); + + -- The actual may be a renamed package, or an outer generic formal + -- package whose instantiation is converted into a renaming. + + if Present (Renamed_Object (Actual_Pack)) then + Actual_Pack := Renamed_Object (Actual_Pack); + end if; + + if Nkind (Analyzed_Formal) = N_Formal_Package_Declaration then + Gen_Parent := Get_Instance_Of (Entity (Name (Analyzed_Formal))); + Formal_Pack := Defining_Identifier (Analyzed_Formal); + else + Gen_Parent := + Generic_Parent (Specification (Analyzed_Formal)); + Formal_Pack := + Defining_Unit_Name (Specification (Analyzed_Formal)); + end if; + + if Nkind (Parent (Actual_Pack)) = N_Defining_Program_Unit_Name then + Parent_Spec := Package_Specification (Actual_Pack); + else + Parent_Spec := Parent (Actual_Pack); + end if; + + if Gen_Parent = Any_Id then + Error_Msg_N + ("previous error in declaration of formal package", Actual); + Abandon_Instantiation (Actual); + + elsif + Is_Instance_Of (Parent_Spec, Get_Instance_Of (Gen_Parent)) + then + null; + + else + Error_Msg_NE + ("actual parameter must be instance of&", Actual, Gen_Parent); + Abandon_Instantiation (Actual); + end if; + + Set_Instance_Of (Defining_Identifier (Formal), Actual_Pack); + Map_Formal_Package_Entities (Formal_Pack, Actual_Pack); + + Nod := + Make_Package_Renaming_Declaration (Loc, + Defining_Unit_Name => New_Copy (Defining_Identifier (Formal)), + Name => New_Occurrence_Of (Actual_Pack, Loc)); + + Set_Associated_Formal_Package (Defining_Unit_Name (Nod), + Defining_Identifier (Formal)); + Decls := New_List (Nod); + + -- If the formal F has a box, then the generic declarations are + -- visible in the generic G. In an instance of G, the corresponding + -- entities in the actual for F (which are the actuals for the + -- instantiation of the generic that F denotes) must also be made + -- visible for analysis of the current instance. On exit from the + -- current instance, those entities are made private again. If the + -- actual is currently in use, these entities are also use-visible. + + -- The loop through the actual entities also steps through the formal + -- entities and enters associations from formals to actuals into the + -- renaming map. This is necessary to properly handle checking of + -- actual parameter associations for later formals that depend on + -- actuals declared in the formal package. + + -- In Ada 2005, partial parameterization requires that we make + -- visible the actuals corresponding to formals that were defaulted + -- in the formal package. There formals are identified because they + -- remain formal generics within the formal package, rather than + -- being renamings of the actuals supplied. + + declare + Gen_Decl : constant Node_Id := + Unit_Declaration_Node (Gen_Parent); + Formals : constant List_Id := + Generic_Formal_Declarations (Gen_Decl); + + Actual_Ent : Entity_Id; + Actual_Of_Formal : Node_Id; + Formal_Node : Node_Id; + Formal_Ent : Entity_Id; + + begin + if Present (Formals) then + Formal_Node := First_Non_Pragma (Formals); + else + Formal_Node := Empty; + end if; + + Actual_Ent := First_Entity (Actual_Pack); + Actual_Of_Formal := + First (Visible_Declarations (Specification (Analyzed_Formal))); + while Present (Actual_Ent) + and then Actual_Ent /= First_Private_Entity (Actual_Pack) + loop + if Present (Formal_Node) then + Formal_Ent := Get_Formal_Entity (Formal_Node); + + if Present (Formal_Ent) then + Find_Matching_Actual (Formal_Node, Actual_Ent); + Match_Formal_Entity + (Formal_Node, Formal_Ent, Actual_Ent); + + -- We iterate at the same time over the actuals of the + -- local package created for the formal, to determine + -- which one of the formals of the original generic were + -- defaulted in the formal. The corresponding actual + -- entities are visible in the enclosing instance. + + if Box_Present (Formal) + or else + (Present (Actual_Of_Formal) + and then + Is_Generic_Formal + (Get_Formal_Entity (Actual_Of_Formal))) + then + Set_Is_Hidden (Actual_Ent, False); + Set_Is_Visible_Formal (Actual_Ent); + Set_Is_Potentially_Use_Visible + (Actual_Ent, In_Use (Actual_Pack)); + + if Ekind (Actual_Ent) = E_Package then + Process_Nested_Formal (Actual_Ent); + end if; + + else + Set_Is_Hidden (Actual_Ent); + Set_Is_Potentially_Use_Visible (Actual_Ent, False); + end if; + end if; + + Next_Non_Pragma (Formal_Node); + Next (Actual_Of_Formal); + + else + -- No further formals to match, but the generic part may + -- contain inherited operation that are not hidden in the + -- enclosing instance. + + Next_Entity (Actual_Ent); + end if; + end loop; + + -- Inherited subprograms generated by formal derived types are + -- also visible if the types are. + + Actual_Ent := First_Entity (Actual_Pack); + while Present (Actual_Ent) + and then Actual_Ent /= First_Private_Entity (Actual_Pack) + loop + if Is_Overloadable (Actual_Ent) + and then + Nkind (Parent (Actual_Ent)) = N_Subtype_Declaration + and then + not Is_Hidden (Defining_Identifier (Parent (Actual_Ent))) + then + Set_Is_Hidden (Actual_Ent, False); + Set_Is_Potentially_Use_Visible + (Actual_Ent, In_Use (Actual_Pack)); + end if; + + Next_Entity (Actual_Ent); + end loop; + end; + + -- If the formal is not declared with a box, reanalyze it as an + -- abbreviated instantiation, to verify the matching rules of 12.7. + -- The actual checks are performed after the generic associations + -- have been analyzed, to guarantee the same visibility for this + -- instantiation and for the actuals. + + -- In Ada 2005, the generic associations for the formal can include + -- defaulted parameters. These are ignored during check. This + -- internal instantiation is removed from the tree after conformance + -- checking, because it contains formal declarations for those + -- defaulted parameters, and those should not reach the back-end. + + if not Box_Present (Formal) then + declare + I_Pack : constant Entity_Id := + Make_Temporary (Sloc (Actual), 'P'); + + begin + Set_Is_Internal (I_Pack); + + Append_To (Decls, + Make_Package_Instantiation (Sloc (Actual), + Defining_Unit_Name => I_Pack, + Name => + New_Occurrence_Of + (Get_Instance_Of (Gen_Parent), Sloc (Actual)), + Generic_Associations => + Generic_Associations (Formal))); + end; + end if; + + return Decls; + end if; + end Instantiate_Formal_Package; + + ----------------------------------- + -- Instantiate_Formal_Subprogram -- + ----------------------------------- + + function Instantiate_Formal_Subprogram + (Formal : Node_Id; + Actual : Node_Id; + Analyzed_Formal : Node_Id) return Node_Id + is + Loc : Source_Ptr; + Formal_Sub : constant Entity_Id := + Defining_Unit_Name (Specification (Formal)); + Analyzed_S : constant Entity_Id := + Defining_Unit_Name (Specification (Analyzed_Formal)); + Decl_Node : Node_Id; + Nam : Node_Id; + New_Spec : Node_Id; + + function From_Parent_Scope (Subp : Entity_Id) return Boolean; + -- If the generic is a child unit, the parent has been installed on the + -- scope stack, but a default subprogram cannot resolve to something + -- on the parent because that parent is not really part of the visible + -- context (it is there to resolve explicit local entities). If the + -- default has resolved in this way, we remove the entity from immediate + -- visibility and analyze the node again to emit an error message or + -- find another visible candidate. + + procedure Valid_Actual_Subprogram (Act : Node_Id); + -- Perform legality check and raise exception on failure + + ----------------------- + -- From_Parent_Scope -- + ----------------------- + + function From_Parent_Scope (Subp : Entity_Id) return Boolean is + Gen_Scope : Node_Id; + + begin + Gen_Scope := Scope (Analyzed_S); + while Present (Gen_Scope) and then Is_Child_Unit (Gen_Scope) loop + if Scope (Subp) = Scope (Gen_Scope) then + return True; + end if; + + Gen_Scope := Scope (Gen_Scope); + end loop; + + return False; + end From_Parent_Scope; + + ----------------------------- + -- Valid_Actual_Subprogram -- + ----------------------------- + + procedure Valid_Actual_Subprogram (Act : Node_Id) is + Act_E : Entity_Id; + + begin + if Is_Entity_Name (Act) then + Act_E := Entity (Act); + + elsif Nkind (Act) = N_Selected_Component + and then Is_Entity_Name (Selector_Name (Act)) + then + Act_E := Entity (Selector_Name (Act)); + + else + Act_E := Empty; + end if; + + if (Present (Act_E) and then Is_Overloadable (Act_E)) + or else Nkind_In (Act, N_Attribute_Reference, + N_Indexed_Component, + N_Character_Literal, + N_Explicit_Dereference) + then + return; + end if; + + Error_Msg_NE + ("expect subprogram or entry name in instantiation of&", + Instantiation_Node, Formal_Sub); + Abandon_Instantiation (Instantiation_Node); + + end Valid_Actual_Subprogram; + + -- Start of processing for Instantiate_Formal_Subprogram + + begin + New_Spec := New_Copy_Tree (Specification (Formal)); + + -- The tree copy has created the proper instantiation sloc for the + -- new specification. Use this location for all other constructed + -- declarations. + + Loc := Sloc (Defining_Unit_Name (New_Spec)); + + -- Create new entity for the actual (New_Copy_Tree does not) + + Set_Defining_Unit_Name + (New_Spec, Make_Defining_Identifier (Loc, Chars (Formal_Sub))); + + -- Create new entities for the each of the formals in the + -- specification of the renaming declaration built for the actual. + + if Present (Parameter_Specifications (New_Spec)) then + declare + F : Node_Id; + begin + F := First (Parameter_Specifications (New_Spec)); + while Present (F) loop + Set_Defining_Identifier (F, + Make_Defining_Identifier (Sloc (F), + Chars => Chars (Defining_Identifier (F)))); + Next (F); + end loop; + end; + end if; + + -- Find entity of actual. If the actual is an attribute reference, it + -- cannot be resolved here (its formal is missing) but is handled + -- instead in Attribute_Renaming. If the actual is overloaded, it is + -- fully resolved subsequently, when the renaming declaration for the + -- formal is analyzed. If it is an explicit dereference, resolve the + -- prefix but not the actual itself, to prevent interpretation as call. + + if Present (Actual) then + Loc := Sloc (Actual); + Set_Sloc (New_Spec, Loc); + + if Nkind (Actual) = N_Operator_Symbol then + Find_Direct_Name (Actual); + + elsif Nkind (Actual) = N_Explicit_Dereference then + Analyze (Prefix (Actual)); + + elsif Nkind (Actual) /= N_Attribute_Reference then + Analyze (Actual); + end if; + + Valid_Actual_Subprogram (Actual); + Nam := Actual; + + elsif Present (Default_Name (Formal)) then + if not Nkind_In (Default_Name (Formal), N_Attribute_Reference, + N_Selected_Component, + N_Indexed_Component, + N_Character_Literal) + and then Present (Entity (Default_Name (Formal))) + then + Nam := New_Occurrence_Of (Entity (Default_Name (Formal)), Loc); + else + Nam := New_Copy (Default_Name (Formal)); + Set_Sloc (Nam, Loc); + end if; + + elsif Box_Present (Formal) then + + -- Actual is resolved at the point of instantiation. Create an + -- identifier or operator with the same name as the formal. + + if Nkind (Formal_Sub) = N_Defining_Operator_Symbol then + Nam := Make_Operator_Symbol (Loc, + Chars => Chars (Formal_Sub), + Strval => No_String); + else + Nam := Make_Identifier (Loc, Chars (Formal_Sub)); + end if; + + elsif Nkind (Specification (Formal)) = N_Procedure_Specification + and then Null_Present (Specification (Formal)) + then + -- Generate null body for procedure, for use in the instance + + Decl_Node := + Make_Subprogram_Body (Loc, + Specification => New_Spec, + Declarations => New_List, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => New_List (Make_Null_Statement (Loc)))); + + Set_Is_Intrinsic_Subprogram (Defining_Unit_Name (New_Spec)); + return Decl_Node; + + else + Error_Msg_Sloc := Sloc (Scope (Analyzed_S)); + Error_Msg_NE + ("missing actual&", Instantiation_Node, Formal_Sub); + Error_Msg_NE + ("\in instantiation of & declared#", + Instantiation_Node, Scope (Analyzed_S)); + Abandon_Instantiation (Instantiation_Node); + end if; + + Decl_Node := + Make_Subprogram_Renaming_Declaration (Loc, + Specification => New_Spec, + Name => Nam); + + -- If we do not have an actual and the formal specified <> then set to + -- get proper default. + + if No (Actual) and then Box_Present (Formal) then + Set_From_Default (Decl_Node); + end if; + + -- Gather possible interpretations for the actual before analyzing the + -- instance. If overloaded, it will be resolved when analyzing the + -- renaming declaration. + + if Box_Present (Formal) + and then No (Actual) + then + Analyze (Nam); + + if Is_Child_Unit (Scope (Analyzed_S)) + and then Present (Entity (Nam)) + then + if not Is_Overloaded (Nam) then + if From_Parent_Scope (Entity (Nam)) then + Set_Is_Immediately_Visible (Entity (Nam), False); + Set_Entity (Nam, Empty); + Set_Etype (Nam, Empty); + + Analyze (Nam); + Set_Is_Immediately_Visible (Entity (Nam)); + end if; + + else + declare + I : Interp_Index; + It : Interp; + + begin + Get_First_Interp (Nam, I, It); + while Present (It.Nam) loop + if From_Parent_Scope (It.Nam) then + Remove_Interp (I); + end if; + + Get_Next_Interp (I, It); + end loop; + end; + end if; + end if; + end if; + + -- The generic instantiation freezes the actual. This can only be done + -- once the actual is resolved, in the analysis of the renaming + -- declaration. To make the formal subprogram entity available, we set + -- Corresponding_Formal_Spec to point to the formal subprogram entity. + -- This is also needed in Analyze_Subprogram_Renaming for the processing + -- of formal abstract subprograms. + + Set_Corresponding_Formal_Spec (Decl_Node, Analyzed_S); + + -- We cannot analyze the renaming declaration, and thus find the actual, + -- until all the actuals are assembled in the instance. For subsequent + -- checks of other actuals, indicate the node that will hold the + -- instance of this formal. + + Set_Instance_Of (Analyzed_S, Nam); + + if Nkind (Actual) = N_Selected_Component + and then Is_Task_Type (Etype (Prefix (Actual))) + and then not Is_Frozen (Etype (Prefix (Actual))) + then + -- The renaming declaration will create a body, which must appear + -- outside of the instantiation, We move the renaming declaration + -- out of the instance, and create an additional renaming inside, + -- to prevent freezing anomalies. + + declare + Anon_Id : constant Entity_Id := Make_Temporary (Loc, 'E'); + + begin + Set_Defining_Unit_Name (New_Spec, Anon_Id); + Insert_Before (Instantiation_Node, Decl_Node); + Analyze (Decl_Node); + + -- Now create renaming within the instance + + Decl_Node := + Make_Subprogram_Renaming_Declaration (Loc, + Specification => New_Copy_Tree (New_Spec), + Name => New_Occurrence_Of (Anon_Id, Loc)); + + Set_Defining_Unit_Name (Specification (Decl_Node), + Make_Defining_Identifier (Loc, Chars (Formal_Sub))); + end; + end if; + + return Decl_Node; + end Instantiate_Formal_Subprogram; + + ------------------------ + -- Instantiate_Object -- + ------------------------ + + function Instantiate_Object + (Formal : Node_Id; + Actual : Node_Id; + Analyzed_Formal : Node_Id) return List_Id + is + Gen_Obj : constant Entity_Id := Defining_Identifier (Formal); + A_Gen_Obj : constant Entity_Id := + Defining_Identifier (Analyzed_Formal); + Acc_Def : Node_Id := Empty; + Act_Assoc : constant Node_Id := Parent (Actual); + Actual_Decl : Node_Id := Empty; + Decl_Node : Node_Id; + Def : Node_Id; + Ftyp : Entity_Id; + List : constant List_Id := New_List; + Loc : constant Source_Ptr := Sloc (Actual); + Orig_Ftyp : constant Entity_Id := Etype (A_Gen_Obj); + Subt_Decl : Node_Id := Empty; + Subt_Mark : Node_Id := Empty; + + begin + if Present (Subtype_Mark (Formal)) then + Subt_Mark := Subtype_Mark (Formal); + else + Check_Access_Definition (Formal); + Acc_Def := Access_Definition (Formal); + end if; + + -- Sloc for error message on missing actual + + Error_Msg_Sloc := Sloc (Scope (A_Gen_Obj)); + + if Get_Instance_Of (Gen_Obj) /= Gen_Obj then + Error_Msg_N ("duplicate instantiation of generic parameter", Actual); + end if; + + Set_Parent (List, Parent (Actual)); + + -- OUT present + + if Out_Present (Formal) then + + -- An IN OUT generic actual must be a name. The instantiation is a + -- renaming declaration. The actual is the name being renamed. We + -- use the actual directly, rather than a copy, because it is not + -- used further in the list of actuals, and because a copy or a use + -- of relocate_node is incorrect if the instance is nested within a + -- generic. In order to simplify ASIS searches, the Generic_Parent + -- field links the declaration to the generic association. + + if No (Actual) then + Error_Msg_NE + ("missing actual&", + Instantiation_Node, Gen_Obj); + Error_Msg_NE + ("\in instantiation of & declared#", + Instantiation_Node, Scope (A_Gen_Obj)); + Abandon_Instantiation (Instantiation_Node); + end if; + + if Present (Subt_Mark) then + Decl_Node := + Make_Object_Renaming_Declaration (Loc, + Defining_Identifier => New_Copy (Gen_Obj), + Subtype_Mark => New_Copy_Tree (Subt_Mark), + Name => Actual); + + else pragma Assert (Present (Acc_Def)); + Decl_Node := + Make_Object_Renaming_Declaration (Loc, + Defining_Identifier => New_Copy (Gen_Obj), + Access_Definition => New_Copy_Tree (Acc_Def), + Name => Actual); + end if; + + Set_Corresponding_Generic_Association (Decl_Node, Act_Assoc); + + -- The analysis of the actual may produce Insert_Action nodes, so + -- the declaration must have a context in which to attach them. + + Append (Decl_Node, List); + Analyze (Actual); + + -- Return if the analysis of the actual reported some error + + if Etype (Actual) = Any_Type then + return List; + end if; + + -- This check is performed here because Analyze_Object_Renaming will + -- not check it when Comes_From_Source is False. Note though that the + -- check for the actual being the name of an object will be performed + -- in Analyze_Object_Renaming. + + if Is_Object_Reference (Actual) + and then Is_Dependent_Component_Of_Mutable_Object (Actual) + then + Error_Msg_N + ("illegal discriminant-dependent component for in out parameter", + Actual); + end if; + + -- The actual has to be resolved in order to check that it is a + -- variable (due to cases such as F (1), where F returns access to + -- an array, and for overloaded prefixes). + + Ftyp := Get_Instance_Of (Etype (A_Gen_Obj)); + + -- If the type of the formal is not itself a formal, and the current + -- unit is a child unit, the formal type must be declared in a + -- parent, and must be retrieved by visibility. + + if Ftyp = Orig_Ftyp + and then Is_Generic_Unit (Scope (Ftyp)) + and then Is_Child_Unit (Scope (A_Gen_Obj)) + then + declare + Temp : constant Node_Id := + New_Copy_Tree (Subtype_Mark (Analyzed_Formal)); + begin + Set_Entity (Temp, Empty); + Find_Type (Temp); + Ftyp := Entity (Temp); + end; + end if; + + if Is_Private_Type (Ftyp) + and then not Is_Private_Type (Etype (Actual)) + and then (Base_Type (Full_View (Ftyp)) = Base_Type (Etype (Actual)) + or else Base_Type (Etype (Actual)) = Ftyp) + then + -- If the actual has the type of the full view of the formal, or + -- else a non-private subtype of the formal, then the visibility + -- of the formal type has changed. Add to the actuals a subtype + -- declaration that will force the exchange of views in the body + -- of the instance as well. + + Subt_Decl := + Make_Subtype_Declaration (Loc, + Defining_Identifier => Make_Temporary (Loc, 'P'), + Subtype_Indication => New_Occurrence_Of (Ftyp, Loc)); + + Prepend (Subt_Decl, List); + + Prepend_Elmt (Full_View (Ftyp), Exchanged_Views); + Exchange_Declarations (Ftyp); + end if; + + Resolve (Actual, Ftyp); + + if not Denotes_Variable (Actual) then + Error_Msg_NE + ("actual for& must be a variable", Actual, Gen_Obj); + + elsif Base_Type (Ftyp) /= Base_Type (Etype (Actual)) then + + -- Ada 2005 (AI-423): For a generic formal object of mode in out, + -- the type of the actual shall resolve to a specific anonymous + -- access type. + + if Ada_Version < Ada_2005 + or else + Ekind (Base_Type (Ftyp)) /= + E_Anonymous_Access_Type + or else + Ekind (Base_Type (Etype (Actual))) /= + E_Anonymous_Access_Type + then + Error_Msg_NE ("type of actual does not match type of&", + Actual, Gen_Obj); + end if; + end if; + + Note_Possible_Modification (Actual, Sure => True); + + -- Check for instantiation of atomic/volatile actual for + -- non-atomic/volatile formal (RM C.6 (12)). + + if Is_Atomic_Object (Actual) + and then not Is_Atomic (Orig_Ftyp) + then + Error_Msg_N + ("cannot instantiate non-atomic formal object " & + "with atomic actual", Actual); + + elsif Is_Volatile_Object (Actual) + and then not Is_Volatile (Orig_Ftyp) + then + Error_Msg_N + ("cannot instantiate non-volatile formal object " & + "with volatile actual", Actual); + end if; + + -- Formal in-parameter + + else + -- The instantiation of a generic formal in-parameter is constant + -- declaration. The actual is the expression for that declaration. + + if Present (Actual) then + if Present (Subt_Mark) then + Def := Subt_Mark; + else pragma Assert (Present (Acc_Def)); + Def := Acc_Def; + end if; + + Decl_Node := + Make_Object_Declaration (Loc, + Defining_Identifier => New_Copy (Gen_Obj), + Constant_Present => True, + Null_Exclusion_Present => Null_Exclusion_Present (Formal), + Object_Definition => New_Copy_Tree (Def), + Expression => Actual); + + Set_Corresponding_Generic_Association (Decl_Node, Act_Assoc); + + -- A generic formal object of a tagged type is defined to be + -- aliased so the new constant must also be treated as aliased. + + if Is_Tagged_Type (Etype (A_Gen_Obj)) then + Set_Aliased_Present (Decl_Node); + end if; + + Append (Decl_Node, List); + + -- No need to repeat (pre-)analysis of some expression nodes + -- already handled in Preanalyze_Actuals. + + if Nkind (Actual) /= N_Allocator then + Analyze (Actual); + + -- Return if the analysis of the actual reported some error + + if Etype (Actual) = Any_Type then + return List; + end if; + end if; + + declare + Formal_Type : constant Entity_Id := Etype (A_Gen_Obj); + Typ : Entity_Id; + + begin + Typ := Get_Instance_Of (Formal_Type); + + Freeze_Before (Instantiation_Node, Typ); + + -- If the actual is an aggregate, perform name resolution on + -- its components (the analysis of an aggregate does not do it) + -- to capture local names that may be hidden if the generic is + -- a child unit. + + if Nkind (Actual) = N_Aggregate then + Preanalyze_And_Resolve (Actual, Typ); + end if; + + if Is_Limited_Type (Typ) + and then not OK_For_Limited_Init (Typ, Actual) + then + Error_Msg_N + ("initialization not allowed for limited types", Actual); + Explain_Limited_Type (Typ, Actual); + end if; + end; + + elsif Present (Default_Expression (Formal)) then + + -- Use default to construct declaration + + if Present (Subt_Mark) then + Def := Subt_Mark; + else pragma Assert (Present (Acc_Def)); + Def := Acc_Def; + end if; + + Decl_Node := + Make_Object_Declaration (Sloc (Formal), + Defining_Identifier => New_Copy (Gen_Obj), + Constant_Present => True, + Null_Exclusion_Present => Null_Exclusion_Present (Formal), + Object_Definition => New_Copy (Def), + Expression => New_Copy_Tree + (Default_Expression (Formal))); + + Append (Decl_Node, List); + Set_Analyzed (Expression (Decl_Node), False); + + else + Error_Msg_NE + ("missing actual&", + Instantiation_Node, Gen_Obj); + Error_Msg_NE ("\in instantiation of & declared#", + Instantiation_Node, Scope (A_Gen_Obj)); + + if Is_Scalar_Type (Etype (A_Gen_Obj)) then + + -- Create dummy constant declaration so that instance can be + -- analyzed, to minimize cascaded visibility errors. + + if Present (Subt_Mark) then + Def := Subt_Mark; + else pragma Assert (Present (Acc_Def)); + Def := Acc_Def; + end if; + + Decl_Node := + Make_Object_Declaration (Loc, + Defining_Identifier => New_Copy (Gen_Obj), + Constant_Present => True, + Null_Exclusion_Present => Null_Exclusion_Present (Formal), + Object_Definition => New_Copy (Def), + Expression => + Make_Attribute_Reference (Sloc (Gen_Obj), + Attribute_Name => Name_First, + Prefix => New_Copy (Def))); + + Append (Decl_Node, List); + + else + Abandon_Instantiation (Instantiation_Node); + end if; + end if; + end if; + + if Nkind (Actual) in N_Has_Entity then + Actual_Decl := Parent (Entity (Actual)); + end if; + + -- Ada 2005 (AI-423): For a formal object declaration with a null + -- exclusion or an access definition that has a null exclusion: If the + -- actual matching the formal object declaration denotes a generic + -- formal object of another generic unit G, and the instantiation + -- containing the actual occurs within the body of G or within the body + -- of a generic unit declared within the declarative region of G, then + -- the declaration of the formal object of G must have a null exclusion. + -- Otherwise, the subtype of the actual matching the formal object + -- declaration shall exclude null. + + if Ada_Version >= Ada_2005 + and then Present (Actual_Decl) + and then + Nkind_In (Actual_Decl, N_Formal_Object_Declaration, + N_Object_Declaration) + and then Nkind (Analyzed_Formal) = N_Formal_Object_Declaration + and then not Has_Null_Exclusion (Actual_Decl) + and then Has_Null_Exclusion (Analyzed_Formal) + then + Error_Msg_Sloc := Sloc (Analyzed_Formal); + Error_Msg_N + ("actual must exclude null to match generic formal#", Actual); + end if; + + -- A volatile object cannot be used as an actual in a generic instance. + -- The following check is only relevant when SPARK_Mode is on as it is + -- not a standard Ada legality rule. + + if SPARK_Mode = On + and then Present (Actual) + and then Is_SPARK_Volatile_Object (Actual) + then + Error_Msg_N + ("volatile object cannot act as actual in generic instantiation " + & "(SPARK RM 7.1.3(8))", Actual); + end if; + + return List; + end Instantiate_Object; + + ------------------------------ + -- Instantiate_Package_Body -- + ------------------------------ + + procedure Instantiate_Package_Body + (Body_Info : Pending_Body_Info; + Inlined_Body : Boolean := False; + Body_Optional : Boolean := False) + is + Act_Decl : constant Node_Id := Body_Info.Act_Decl; + Inst_Node : constant Node_Id := Body_Info.Inst_Node; + Loc : constant Source_Ptr := Sloc (Inst_Node); + + Gen_Id : constant Node_Id := Name (Inst_Node); + Gen_Unit : constant Entity_Id := Get_Generic_Entity (Inst_Node); + Gen_Decl : constant Node_Id := Unit_Declaration_Node (Gen_Unit); + Act_Spec : constant Node_Id := Specification (Act_Decl); + Act_Decl_Id : constant Entity_Id := Defining_Entity (Act_Spec); + + Act_Body_Name : Node_Id; + Gen_Body : Node_Id; + Gen_Body_Id : Node_Id; + Act_Body : Node_Id; + Act_Body_Id : Entity_Id; + + Parent_Installed : Boolean := False; + Save_Style_Check : constant Boolean := Style_Check; + + Par_Ent : Entity_Id := Empty; + Par_Vis : Boolean := False; + + Vis_Prims_List : Elist_Id := No_Elist; + -- List of primitives made temporarily visible in the instantiation + -- to match the visibility of the formal type + + begin + Gen_Body_Id := Corresponding_Body (Gen_Decl); + + -- The instance body may already have been processed, as the parent of + -- another instance that is inlined (Load_Parent_Of_Generic). + + if Present (Corresponding_Body (Instance_Spec (Inst_Node))) then + return; + end if; + + Expander_Mode_Save_And_Set (Body_Info.Expander_Status); + + -- Re-establish the state of information on which checks are suppressed. + -- This information was set in Body_Info at the point of instantiation, + -- and now we restore it so that the instance is compiled using the + -- check status at the instantiation (RM 11.5 (7.2/2), AI95-00224-01). + + Local_Suppress_Stack_Top := Body_Info.Local_Suppress_Stack_Top; + Scope_Suppress := Body_Info.Scope_Suppress; + Opt.Ada_Version := Body_Info.Version; + Opt.Ada_Version_Pragma := Body_Info.Version_Pragma; + Restore_Warnings (Body_Info.Warnings); + Opt.SPARK_Mode := Body_Info.SPARK_Mode; + Opt.SPARK_Mode_Pragma := Body_Info.SPARK_Mode_Pragma; + + if No (Gen_Body_Id) then + Load_Parent_Of_Generic + (Inst_Node, Specification (Gen_Decl), Body_Optional); + Gen_Body_Id := Corresponding_Body (Gen_Decl); + end if; + + -- Establish global variable for sloc adjustment and for error recovery + + Instantiation_Node := Inst_Node; + + if Present (Gen_Body_Id) then + Save_Env (Gen_Unit, Act_Decl_Id); + Style_Check := False; + Current_Sem_Unit := Body_Info.Current_Sem_Unit; + + Gen_Body := Unit_Declaration_Node (Gen_Body_Id); + + Create_Instantiation_Source + (Inst_Node, Gen_Body_Id, False, S_Adjustment); + + Act_Body := + Copy_Generic_Node + (Original_Node (Gen_Body), Empty, Instantiating => True); + + -- Build new name (possibly qualified) for body declaration + + Act_Body_Id := New_Copy (Act_Decl_Id); + + -- Some attributes of spec entity are not inherited by body entity + + Set_Handler_Records (Act_Body_Id, No_List); + + if Nkind (Defining_Unit_Name (Act_Spec)) = + N_Defining_Program_Unit_Name + then + Act_Body_Name := + Make_Defining_Program_Unit_Name (Loc, + Name => New_Copy_Tree (Name (Defining_Unit_Name (Act_Spec))), + Defining_Identifier => Act_Body_Id); + else + Act_Body_Name := Act_Body_Id; + end if; + + Set_Defining_Unit_Name (Act_Body, Act_Body_Name); + + Set_Corresponding_Spec (Act_Body, Act_Decl_Id); + Check_Generic_Actuals (Act_Decl_Id, False); + + -- Install primitives hidden at the point of the instantiation but + -- visible when processing the generic formals + + declare + E : Entity_Id; + + begin + E := First_Entity (Act_Decl_Id); + while Present (E) loop + if Is_Type (E) + and then Is_Generic_Actual_Type (E) + and then Is_Tagged_Type (E) + then + Install_Hidden_Primitives + (Prims_List => Vis_Prims_List, + Gen_T => Generic_Parent_Type (Parent (E)), + Act_T => E); + end if; + + Next_Entity (E); + end loop; + end; + + -- If it is a child unit, make the parent instance (which is an + -- instance of the parent of the generic) visible. The parent + -- instance is the prefix of the name of the generic unit. + + if Ekind (Scope (Gen_Unit)) = E_Generic_Package + and then Nkind (Gen_Id) = N_Expanded_Name + then + Par_Ent := Entity (Prefix (Gen_Id)); + Par_Vis := Is_Immediately_Visible (Par_Ent); + Install_Parent (Par_Ent, In_Body => True); + Parent_Installed := True; + + elsif Is_Child_Unit (Gen_Unit) then + Par_Ent := Scope (Gen_Unit); + Par_Vis := Is_Immediately_Visible (Par_Ent); + Install_Parent (Par_Ent, In_Body => True); + Parent_Installed := True; + end if; + + -- If the instantiation is a library unit, and this is the main unit, + -- then build the resulting compilation unit nodes for the instance. + -- If this is a compilation unit but it is not the main unit, then it + -- is the body of a unit in the context, that is being compiled + -- because it is encloses some inlined unit or another generic unit + -- being instantiated. In that case, this body is not part of the + -- current compilation, and is not attached to the tree, but its + -- parent must be set for analysis. + + if Nkind (Parent (Inst_Node)) = N_Compilation_Unit then + + -- Replace instance node with body of instance, and create new + -- node for corresponding instance declaration. + + Build_Instance_Compilation_Unit_Nodes + (Inst_Node, Act_Body, Act_Decl); + Analyze (Inst_Node); + + if Parent (Inst_Node) = Cunit (Main_Unit) then + + -- If the instance is a child unit itself, then set the scope + -- of the expanded body to be the parent of the instantiation + -- (ensuring that the fully qualified name will be generated + -- for the elaboration subprogram). + + if Nkind (Defining_Unit_Name (Act_Spec)) = + N_Defining_Program_Unit_Name + then + Set_Scope + (Defining_Entity (Inst_Node), Scope (Act_Decl_Id)); + end if; + end if; + + -- Case where instantiation is not a library unit + + else + -- If this is an early instantiation, i.e. appears textually + -- before the corresponding body and must be elaborated first, + -- indicate that the body instance is to be delayed. + + Install_Body (Act_Body, Inst_Node, Gen_Body, Gen_Decl); + + -- Now analyze the body. We turn off all checks if this is an + -- internal unit, since there is no reason to have checks on for + -- any predefined run-time library code. All such code is designed + -- to be compiled with checks off. + + -- Note that we do NOT apply this criterion to children of GNAT + -- (or on VMS, children of DEC). The latter units must suppress + -- checks explicitly if this is needed. + + if Is_Predefined_File_Name + (Unit_File_Name (Get_Source_Unit (Gen_Decl))) + then + Analyze (Act_Body, Suppress => All_Checks); + else + Analyze (Act_Body); + end if; + end if; + + Inherit_Context (Gen_Body, Inst_Node); + + -- Remove the parent instances if they have been placed on the scope + -- stack to compile the body. + + if Parent_Installed then + Remove_Parent (In_Body => True); + + -- Restore the previous visibility of the parent + + Set_Is_Immediately_Visible (Par_Ent, Par_Vis); + end if; + + Restore_Hidden_Primitives (Vis_Prims_List); + Restore_Private_Views (Act_Decl_Id); + + -- Remove the current unit from visibility if this is an instance + -- that is not elaborated on the fly for inlining purposes. + + if not Inlined_Body then + Set_Is_Immediately_Visible (Act_Decl_Id, False); + end if; + + Restore_Env; + Style_Check := Save_Style_Check; + + -- If we have no body, and the unit requires a body, then complain. This + -- complaint is suppressed if we have detected other errors (since a + -- common reason for missing the body is that it had errors). + -- In CodePeer mode, a warning has been emitted already, no need for + -- further messages. + + elsif Unit_Requires_Body (Gen_Unit) + and then not Body_Optional + then + if CodePeer_Mode then + null; + + elsif Serious_Errors_Detected = 0 then + Error_Msg_NE + ("cannot find body of generic package &", Inst_Node, Gen_Unit); + + -- Don't attempt to perform any cleanup actions if some other error + -- was already detected, since this can cause blowups. + + else + return; + end if; + + -- Case of package that does not need a body + + else + -- If the instantiation of the declaration is a library unit, rewrite + -- the original package instantiation as a package declaration in the + -- compilation unit node. + + if Nkind (Parent (Inst_Node)) = N_Compilation_Unit then + Set_Parent_Spec (Act_Decl, Parent_Spec (Inst_Node)); + Rewrite (Inst_Node, Act_Decl); + + -- Generate elaboration entity, in case spec has elaboration code. + -- This cannot be done when the instance is analyzed, because it + -- is not known yet whether the body exists. + + Set_Elaboration_Entity_Required (Act_Decl_Id, False); + Build_Elaboration_Entity (Parent (Inst_Node), Act_Decl_Id); + + -- If the instantiation is not a library unit, then append the + -- declaration to the list of implicitly generated entities, unless + -- it is already a list member which means that it was already + -- processed + + elsif not Is_List_Member (Act_Decl) then + Mark_Rewrite_Insertion (Act_Decl); + Insert_Before (Inst_Node, Act_Decl); + end if; + end if; + + Expander_Mode_Restore; + end Instantiate_Package_Body; + + --------------------------------- + -- Instantiate_Subprogram_Body -- + --------------------------------- + + procedure Instantiate_Subprogram_Body + (Body_Info : Pending_Body_Info; + Body_Optional : Boolean := False) + is + Act_Decl : constant Node_Id := Body_Info.Act_Decl; + Inst_Node : constant Node_Id := Body_Info.Inst_Node; + Loc : constant Source_Ptr := Sloc (Inst_Node); + Gen_Id : constant Node_Id := Name (Inst_Node); + Gen_Unit : constant Entity_Id := Get_Generic_Entity (Inst_Node); + Gen_Decl : constant Node_Id := Unit_Declaration_Node (Gen_Unit); + Anon_Id : constant Entity_Id := + Defining_Unit_Name (Specification (Act_Decl)); + Pack_Id : constant Entity_Id := + Defining_Unit_Name (Parent (Act_Decl)); + Decls : List_Id; + Gen_Body : Node_Id; + Gen_Body_Id : Node_Id; + Act_Body : Node_Id; + Pack_Body : Node_Id; + Prev_Formal : Entity_Id; + Ret_Expr : Node_Id; + Unit_Renaming : Node_Id; + + Parent_Installed : Boolean := False; + + Saved_Style_Check : constant Boolean := Style_Check; + Saved_Warnings : constant Warning_Record := Save_Warnings; + + Par_Ent : Entity_Id := Empty; + Par_Vis : Boolean := False; + + begin + Gen_Body_Id := Corresponding_Body (Gen_Decl); + + -- Subprogram body may have been created already because of an inline + -- pragma, or because of multiple elaborations of the enclosing package + -- when several instances of the subprogram appear in the main unit. + + if Present (Corresponding_Body (Act_Decl)) then + return; + end if; + + Expander_Mode_Save_And_Set (Body_Info.Expander_Status); + + -- Re-establish the state of information on which checks are suppressed. + -- This information was set in Body_Info at the point of instantiation, + -- and now we restore it so that the instance is compiled using the + -- check status at the instantiation (RM 11.5 (7.2/2), AI95-00224-01). + + Local_Suppress_Stack_Top := Body_Info.Local_Suppress_Stack_Top; + Scope_Suppress := Body_Info.Scope_Suppress; + Opt.Ada_Version := Body_Info.Version; + Opt.Ada_Version_Pragma := Body_Info.Version_Pragma; + Restore_Warnings (Body_Info.Warnings); + Opt.SPARK_Mode := Body_Info.SPARK_Mode; + Opt.SPARK_Mode_Pragma := Body_Info.SPARK_Mode_Pragma; + + if No (Gen_Body_Id) then + + -- For imported generic subprogram, no body to compile, complete + -- the spec entity appropriately. + + if Is_Imported (Gen_Unit) then + Set_Is_Imported (Anon_Id); + Set_First_Rep_Item (Anon_Id, First_Rep_Item (Gen_Unit)); + Set_Interface_Name (Anon_Id, Interface_Name (Gen_Unit)); + Set_Convention (Anon_Id, Convention (Gen_Unit)); + Set_Has_Completion (Anon_Id); + return; + + -- For other cases, compile the body + + else + Load_Parent_Of_Generic + (Inst_Node, Specification (Gen_Decl), Body_Optional); + Gen_Body_Id := Corresponding_Body (Gen_Decl); + end if; + end if; + + Instantiation_Node := Inst_Node; + + if Present (Gen_Body_Id) then + Gen_Body := Unit_Declaration_Node (Gen_Body_Id); + + if Nkind (Gen_Body) = N_Subprogram_Body_Stub then + + -- Either body is not present, or context is non-expanding, as + -- when compiling a subunit. Mark the instance as completed, and + -- diagnose a missing body when needed. + + if Expander_Active + and then Operating_Mode = Generate_Code + then + Error_Msg_N + ("missing proper body for instantiation", Gen_Body); + end if; + + Set_Has_Completion (Anon_Id); + return; + end if; + + Save_Env (Gen_Unit, Anon_Id); + Style_Check := False; + Current_Sem_Unit := Body_Info.Current_Sem_Unit; + Create_Instantiation_Source + (Inst_Node, + Gen_Body_Id, + False, + S_Adjustment); + + Act_Body := + Copy_Generic_Node + (Original_Node (Gen_Body), Empty, Instantiating => True); + + -- Create proper defining name for the body, to correspond to + -- the one in the spec. + + Set_Defining_Unit_Name (Specification (Act_Body), + Make_Defining_Identifier + (Sloc (Defining_Entity (Inst_Node)), Chars (Anon_Id))); + Set_Corresponding_Spec (Act_Body, Anon_Id); + Set_Has_Completion (Anon_Id); + Check_Generic_Actuals (Pack_Id, False); + + -- Generate a reference to link the visible subprogram instance to + -- the generic body, which for navigation purposes is the only + -- available source for the instance. + + Generate_Reference + (Related_Instance (Pack_Id), + Gen_Body_Id, 'b', Set_Ref => False, Force => True); + + -- If it is a child unit, make the parent instance (which is an + -- instance of the parent of the generic) visible. The parent + -- instance is the prefix of the name of the generic unit. + + if Ekind (Scope (Gen_Unit)) = E_Generic_Package + and then Nkind (Gen_Id) = N_Expanded_Name + then + Par_Ent := Entity (Prefix (Gen_Id)); + Par_Vis := Is_Immediately_Visible (Par_Ent); + Install_Parent (Par_Ent, In_Body => True); + Parent_Installed := True; + + elsif Is_Child_Unit (Gen_Unit) then + Par_Ent := Scope (Gen_Unit); + Par_Vis := Is_Immediately_Visible (Par_Ent); + Install_Parent (Par_Ent, In_Body => True); + Parent_Installed := True; + end if; + + -- Inside its body, a reference to the generic unit is a reference + -- to the instance. The corresponding renaming is the first + -- declaration in the body. + + Unit_Renaming := + Make_Subprogram_Renaming_Declaration (Loc, + Specification => + Copy_Generic_Node ( + Specification (Original_Node (Gen_Body)), + Empty, + Instantiating => True), + Name => New_Occurrence_Of (Anon_Id, Loc)); + + -- If there is a formal subprogram with the same name as the unit + -- itself, do not add this renaming declaration. This is a temporary + -- fix for one ACVC test. ??? + + Prev_Formal := First_Entity (Pack_Id); + while Present (Prev_Formal) loop + if Chars (Prev_Formal) = Chars (Gen_Unit) + and then Is_Overloadable (Prev_Formal) + then + exit; + end if; + + Next_Entity (Prev_Formal); + end loop; + + if Present (Prev_Formal) then + Decls := New_List (Act_Body); + else + Decls := New_List (Unit_Renaming, Act_Body); + end if; + + -- The subprogram body is placed in the body of a dummy package body, + -- whose spec contains the subprogram declaration as well as the + -- renaming declarations for the generic parameters. + + Pack_Body := Make_Package_Body (Loc, + Defining_Unit_Name => New_Copy (Pack_Id), + Declarations => Decls); + + Set_Corresponding_Spec (Pack_Body, Pack_Id); + + -- If the instantiation is a library unit, then build resulting + -- compilation unit nodes for the instance. The declaration of + -- the enclosing package is the grandparent of the subprogram + -- declaration. First replace the instantiation node as the unit + -- of the corresponding compilation. + + if Nkind (Parent (Inst_Node)) = N_Compilation_Unit then + if Parent (Inst_Node) = Cunit (Main_Unit) then + Set_Unit (Parent (Inst_Node), Inst_Node); + Build_Instance_Compilation_Unit_Nodes + (Inst_Node, Pack_Body, Parent (Parent (Act_Decl))); + Analyze (Inst_Node); + else + Set_Parent (Pack_Body, Parent (Inst_Node)); + Analyze (Pack_Body); + end if; + + else + Insert_Before (Inst_Node, Pack_Body); + Mark_Rewrite_Insertion (Pack_Body); + Analyze (Pack_Body); + + if Expander_Active then + Freeze_Subprogram_Body (Inst_Node, Gen_Body, Pack_Id); + end if; + end if; + + Inherit_Context (Gen_Body, Inst_Node); + + Restore_Private_Views (Pack_Id, False); + + if Parent_Installed then + Remove_Parent (In_Body => True); + + -- Restore the previous visibility of the parent + + Set_Is_Immediately_Visible (Par_Ent, Par_Vis); + end if; + + Restore_Env; + Style_Check := Saved_Style_Check; + Restore_Warnings (Saved_Warnings); + + -- Body not found. Error was emitted already. If there were no previous + -- errors, this may be an instance whose scope is a premature instance. + -- In that case we must insure that the (legal) program does raise + -- program error if executed. We generate a subprogram body for this + -- purpose. See DEC ac30vso. + + -- Should not reference proprietary DEC tests in comments ??? + + elsif Serious_Errors_Detected = 0 + and then Nkind (Parent (Inst_Node)) /= N_Compilation_Unit + then + if Body_Optional then + return; + + elsif Ekind (Anon_Id) = E_Procedure then + Act_Body := + Make_Subprogram_Body (Loc, + Specification => + Make_Procedure_Specification (Loc, + Defining_Unit_Name => + Make_Defining_Identifier (Loc, Chars (Anon_Id)), + Parameter_Specifications => + New_Copy_List + (Parameter_Specifications (Parent (Anon_Id)))), + + Declarations => Empty_List, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => + New_List ( + Make_Raise_Program_Error (Loc, + Reason => + PE_Access_Before_Elaboration)))); + + else + Ret_Expr := + Make_Raise_Program_Error (Loc, + Reason => PE_Access_Before_Elaboration); + + Set_Etype (Ret_Expr, (Etype (Anon_Id))); + Set_Analyzed (Ret_Expr); + + Act_Body := + Make_Subprogram_Body (Loc, + Specification => + Make_Function_Specification (Loc, + Defining_Unit_Name => + Make_Defining_Identifier (Loc, Chars (Anon_Id)), + Parameter_Specifications => + New_Copy_List + (Parameter_Specifications (Parent (Anon_Id))), + Result_Definition => + New_Occurrence_Of (Etype (Anon_Id), Loc)), + + Declarations => Empty_List, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => + New_List + (Make_Simple_Return_Statement (Loc, Ret_Expr)))); + end if; + + Pack_Body := Make_Package_Body (Loc, + Defining_Unit_Name => New_Copy (Pack_Id), + Declarations => New_List (Act_Body)); + + Insert_After (Inst_Node, Pack_Body); + Set_Corresponding_Spec (Pack_Body, Pack_Id); + Analyze (Pack_Body); + end if; + + Expander_Mode_Restore; + end Instantiate_Subprogram_Body; + + ---------------------- + -- Instantiate_Type -- + ---------------------- + + function Instantiate_Type + (Formal : Node_Id; + Actual : Node_Id; + Analyzed_Formal : Node_Id; + Actual_Decls : List_Id) return List_Id + is + Gen_T : constant Entity_Id := Defining_Identifier (Formal); + A_Gen_T : constant Entity_Id := + Defining_Identifier (Analyzed_Formal); + Ancestor : Entity_Id := Empty; + Def : constant Node_Id := Formal_Type_Definition (Formal); + Act_T : Entity_Id; + Decl_Node : Node_Id; + Decl_Nodes : List_Id; + Loc : Source_Ptr; + Subt : Entity_Id; + + procedure Validate_Array_Type_Instance; + procedure Validate_Access_Subprogram_Instance; + procedure Validate_Access_Type_Instance; + procedure Validate_Derived_Type_Instance; + procedure Validate_Derived_Interface_Type_Instance; + procedure Validate_Discriminated_Formal_Type; + procedure Validate_Interface_Type_Instance; + procedure Validate_Private_Type_Instance; + procedure Validate_Incomplete_Type_Instance; + -- These procedures perform validation tests for the named case. + -- Validate_Discriminated_Formal_Type is shared by formal private + -- types and Ada 2012 formal incomplete types. + + function Subtypes_Match (Gen_T, Act_T : Entity_Id) return Boolean; + -- Check that base types are the same and that the subtypes match + -- statically. Used in several of the above. + + -------------------- + -- Subtypes_Match -- + -------------------- + + function Subtypes_Match (Gen_T, Act_T : Entity_Id) return Boolean is + T : constant Entity_Id := Get_Instance_Of (Gen_T); + + begin + -- Some detailed comments would be useful here ??? + + return ((Base_Type (T) = Act_T + or else Base_Type (T) = Base_Type (Act_T)) + and then Subtypes_Statically_Match (T, Act_T)) + + or else (Is_Class_Wide_Type (Gen_T) + and then Is_Class_Wide_Type (Act_T) + and then Subtypes_Match + (Get_Instance_Of (Root_Type (Gen_T)), + Root_Type (Act_T))) + + or else + (Ekind_In (Gen_T, E_Anonymous_Access_Subprogram_Type, + E_Anonymous_Access_Type) + and then Ekind (Act_T) = Ekind (Gen_T) + and then Subtypes_Statically_Match + (Designated_Type (Gen_T), Designated_Type (Act_T))); + end Subtypes_Match; + + ----------------------------------------- + -- Validate_Access_Subprogram_Instance -- + ----------------------------------------- + + procedure Validate_Access_Subprogram_Instance is + begin + if not Is_Access_Type (Act_T) + or else Ekind (Designated_Type (Act_T)) /= E_Subprogram_Type + then + Error_Msg_NE + ("expect access type in instantiation of &", Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + -- According to AI05-288, actuals for access_to_subprograms must be + -- subtype conformant with the generic formal. Previous to AI05-288 + -- only mode conformance was required. + + -- This is a binding interpretation that applies to previous versions + -- of the language, no need to maintain previous weaker checks. + + Check_Subtype_Conformant + (Designated_Type (Act_T), + Designated_Type (A_Gen_T), + Actual, + Get_Inst => True); + + if Ekind (Base_Type (Act_T)) = E_Access_Protected_Subprogram_Type then + if Ekind (A_Gen_T) = E_Access_Subprogram_Type then + Error_Msg_NE + ("protected access type not allowed for formal &", + Actual, Gen_T); + end if; + + elsif Ekind (A_Gen_T) = E_Access_Protected_Subprogram_Type then + Error_Msg_NE + ("expect protected access type for formal &", + Actual, Gen_T); + end if; + end Validate_Access_Subprogram_Instance; + + ----------------------------------- + -- Validate_Access_Type_Instance -- + ----------------------------------- + + procedure Validate_Access_Type_Instance is + Desig_Type : constant Entity_Id := + Find_Actual_Type (Designated_Type (A_Gen_T), A_Gen_T); + Desig_Act : Entity_Id; + + begin + if not Is_Access_Type (Act_T) then + Error_Msg_NE + ("expect access type in instantiation of &", Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + if Is_Access_Constant (A_Gen_T) then + if not Is_Access_Constant (Act_T) then + Error_Msg_N + ("actual type must be access-to-constant type", Actual); + Abandon_Instantiation (Actual); + end if; + else + if Is_Access_Constant (Act_T) then + Error_Msg_N + ("actual type must be access-to-variable type", Actual); + Abandon_Instantiation (Actual); + + elsif Ekind (A_Gen_T) = E_General_Access_Type + and then Ekind (Base_Type (Act_T)) /= E_General_Access_Type + then + Error_Msg_N -- CODEFIX + ("actual must be general access type!", Actual); + Error_Msg_NE -- CODEFIX + ("add ALL to }!", Actual, Act_T); + Abandon_Instantiation (Actual); + end if; + end if; + + -- The designated subtypes, that is to say the subtypes introduced + -- by an access type declaration (and not by a subtype declaration) + -- must match. + + Desig_Act := Designated_Type (Base_Type (Act_T)); + + -- The designated type may have been introduced through a limited_ + -- with clause, in which case retrieve the non-limited view. This + -- applies to incomplete types as well as to class-wide types. + + if From_Limited_With (Desig_Act) then + Desig_Act := Available_View (Desig_Act); + end if; + + if not Subtypes_Match (Desig_Type, Desig_Act) then + Error_Msg_NE + ("designated type of actual does not match that of formal &", + Actual, Gen_T); + + if not Predicates_Match (Desig_Type, Desig_Act) then + Error_Msg_N ("\predicates do not match", Actual); + end if; + + Abandon_Instantiation (Actual); + + elsif Is_Access_Type (Designated_Type (Act_T)) + and then Is_Constrained (Designated_Type (Designated_Type (Act_T))) + /= + Is_Constrained (Designated_Type (Desig_Type)) + then + Error_Msg_NE + ("designated type of actual does not match that of formal &", + Actual, Gen_T); + + if not Predicates_Match (Desig_Type, Desig_Act) then + Error_Msg_N ("\predicates do not match", Actual); + end if; + + Abandon_Instantiation (Actual); + end if; + + -- Ada 2005: null-exclusion indicators of the two types must agree + + if Can_Never_Be_Null (A_Gen_T) /= Can_Never_Be_Null (Act_T) then + Error_Msg_NE + ("non null exclusion of actual and formal & do not match", + Actual, Gen_T); + end if; + end Validate_Access_Type_Instance; + + ---------------------------------- + -- Validate_Array_Type_Instance -- + ---------------------------------- + + procedure Validate_Array_Type_Instance is + I1 : Node_Id; + I2 : Node_Id; + T2 : Entity_Id; + + function Formal_Dimensions return Int; + -- Count number of dimensions in array type formal + + ----------------------- + -- Formal_Dimensions -- + ----------------------- + + function Formal_Dimensions return Int is + Num : Int := 0; + Index : Node_Id; + + begin + if Nkind (Def) = N_Constrained_Array_Definition then + Index := First (Discrete_Subtype_Definitions (Def)); + else + Index := First (Subtype_Marks (Def)); + end if; + + while Present (Index) loop + Num := Num + 1; + Next_Index (Index); + end loop; + + return Num; + end Formal_Dimensions; + + -- Start of processing for Validate_Array_Type_Instance + + begin + if not Is_Array_Type (Act_T) then + Error_Msg_NE + ("expect array type in instantiation of &", Actual, Gen_T); + Abandon_Instantiation (Actual); + + elsif Nkind (Def) = N_Constrained_Array_Definition then + if not (Is_Constrained (Act_T)) then + Error_Msg_NE + ("expect constrained array in instantiation of &", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + else + if Is_Constrained (Act_T) then + Error_Msg_NE + ("expect unconstrained array in instantiation of &", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + end if; + + if Formal_Dimensions /= Number_Dimensions (Act_T) then + Error_Msg_NE + ("dimensions of actual do not match formal &", Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + I1 := First_Index (A_Gen_T); + I2 := First_Index (Act_T); + for J in 1 .. Formal_Dimensions loop + + -- If the indexes of the actual were given by a subtype_mark, + -- the index was transformed into a range attribute. Retrieve + -- the original type mark for checking. + + if Is_Entity_Name (Original_Node (I2)) then + T2 := Entity (Original_Node (I2)); + else + T2 := Etype (I2); + end if; + + if not Subtypes_Match + (Find_Actual_Type (Etype (I1), A_Gen_T), T2) + then + Error_Msg_NE + ("index types of actual do not match those of formal &", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + Next_Index (I1); + Next_Index (I2); + end loop; + + -- Check matching subtypes. Note that there are complex visibility + -- issues when the generic is a child unit and some aspect of the + -- generic type is declared in a parent unit of the generic. We do + -- the test to handle this special case only after a direct check + -- for static matching has failed. The case where both the component + -- type and the array type are separate formals, and the component + -- type is a private view may also require special checking in + -- Subtypes_Match. + + if Subtypes_Match + (Component_Type (A_Gen_T), Component_Type (Act_T)) + or else Subtypes_Match + (Find_Actual_Type (Component_Type (A_Gen_T), A_Gen_T), + Component_Type (Act_T)) + then + null; + else + Error_Msg_NE + ("component subtype of actual does not match that of formal &", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + if Has_Aliased_Components (A_Gen_T) + and then not Has_Aliased_Components (Act_T) + then + Error_Msg_NE + ("actual must have aliased components to match formal type &", + Actual, Gen_T); + end if; + end Validate_Array_Type_Instance; + + ----------------------------------------------- + -- Validate_Derived_Interface_Type_Instance -- + ----------------------------------------------- + + procedure Validate_Derived_Interface_Type_Instance is + Par : constant Entity_Id := Entity (Subtype_Indication (Def)); + Elmt : Elmt_Id; + + begin + -- First apply interface instance checks + + Validate_Interface_Type_Instance; + + -- Verify that immediate parent interface is an ancestor of + -- the actual. + + if Present (Par) + and then not Interface_Present_In_Ancestor (Act_T, Par) + then + Error_Msg_NE + ("interface actual must include progenitor&", Actual, Par); + end if; + + -- Now verify that the actual includes all other ancestors of + -- the formal. + + Elmt := First_Elmt (Interfaces (A_Gen_T)); + while Present (Elmt) loop + if not Interface_Present_In_Ancestor + (Act_T, Get_Instance_Of (Node (Elmt))) + then + Error_Msg_NE + ("interface actual must include progenitor&", + Actual, Node (Elmt)); + end if; + + Next_Elmt (Elmt); + end loop; + end Validate_Derived_Interface_Type_Instance; + + ------------------------------------ + -- Validate_Derived_Type_Instance -- + ------------------------------------ + + procedure Validate_Derived_Type_Instance is + Actual_Discr : Entity_Id; + Ancestor_Discr : Entity_Id; + + begin + -- If the parent type in the generic declaration is itself a previous + -- formal type, then it is local to the generic and absent from the + -- analyzed generic definition. In that case the ancestor is the + -- instance of the formal (which must have been instantiated + -- previously), unless the ancestor is itself a formal derived type. + -- In this latter case (which is the subject of Corrigendum 8652/0038 + -- (AI-202) the ancestor of the formals is the ancestor of its + -- parent. Otherwise, the analyzed generic carries the parent type. + -- If the parent type is defined in a previous formal package, then + -- the scope of that formal package is that of the generic type + -- itself, and it has already been mapped into the corresponding type + -- in the actual package. + + -- Common case: parent type defined outside of the generic + + if Is_Entity_Name (Subtype_Mark (Def)) + and then Present (Entity (Subtype_Mark (Def))) + then + Ancestor := Get_Instance_Of (Entity (Subtype_Mark (Def))); + + -- Check whether parent is defined in a previous formal package + + elsif + Scope (Scope (Base_Type (Etype (A_Gen_T)))) = Scope (A_Gen_T) + then + Ancestor := + Get_Instance_Of (Base_Type (Etype (A_Gen_T))); + + -- The type may be a local derivation, or a type extension of a + -- previous formal, or of a formal of a parent package. + + elsif Is_Derived_Type (Get_Instance_Of (A_Gen_T)) + or else + Ekind (Get_Instance_Of (A_Gen_T)) = E_Record_Type_With_Private + then + -- Check whether the parent is another derived formal type in the + -- same generic unit. + + if Etype (A_Gen_T) /= A_Gen_T + and then Is_Generic_Type (Etype (A_Gen_T)) + and then Scope (Etype (A_Gen_T)) = Scope (A_Gen_T) + and then Etype (Etype (A_Gen_T)) /= Etype (A_Gen_T) + then + -- Locate ancestor of parent from the subtype declaration + -- created for the actual. + + declare + Decl : Node_Id; + + begin + Decl := First (Actual_Decls); + while Present (Decl) loop + if Nkind (Decl) = N_Subtype_Declaration + and then Chars (Defining_Identifier (Decl)) = + Chars (Etype (A_Gen_T)) + then + Ancestor := Generic_Parent_Type (Decl); + exit; + else + Next (Decl); + end if; + end loop; + end; + + pragma Assert (Present (Ancestor)); + + -- The ancestor itself may be a previous formal that has been + -- instantiated. + + Ancestor := Get_Instance_Of (Ancestor); + + else + Ancestor := + Get_Instance_Of (Base_Type (Get_Instance_Of (A_Gen_T))); + end if; + + -- An unusual case: the actual is a type declared in a parent unit, + -- but is not a formal type so there is no instance_of for it. + -- Retrieve it by analyzing the record extension. + + elsif Is_Child_Unit (Scope (A_Gen_T)) + and then In_Open_Scopes (Scope (Act_T)) + and then Is_Generic_Instance (Scope (Act_T)) + then + Analyze (Subtype_Mark (Def)); + Ancestor := Entity (Subtype_Mark (Def)); + + else + Ancestor := Get_Instance_Of (Etype (Base_Type (A_Gen_T))); + end if; + + -- If the formal derived type has pragma Preelaborable_Initialization + -- then the actual type must have preelaborable initialization. + + if Known_To_Have_Preelab_Init (A_Gen_T) + and then not Has_Preelaborable_Initialization (Act_T) + then + Error_Msg_NE + ("actual for & must have preelaborable initialization", + Actual, Gen_T); + end if; + + -- Ada 2005 (AI-251) + + if Ada_Version >= Ada_2005 and then Is_Interface (Ancestor) then + if not Interface_Present_In_Ancestor (Act_T, Ancestor) then + Error_Msg_NE + ("(Ada 2005) expected type implementing & in instantiation", + Actual, Ancestor); + end if; + + elsif not Is_Ancestor (Base_Type (Ancestor), Act_T) then + Error_Msg_NE + ("expect type derived from & in instantiation", + Actual, First_Subtype (Ancestor)); + Abandon_Instantiation (Actual); + end if; + + -- Ada 2005 (AI-443): Synchronized formal derived type checks. Note + -- that the formal type declaration has been rewritten as a private + -- extension. + + if Ada_Version >= Ada_2005 + and then Nkind (Parent (A_Gen_T)) = N_Private_Extension_Declaration + and then Synchronized_Present (Parent (A_Gen_T)) + then + -- The actual must be a synchronized tagged type + + if not Is_Tagged_Type (Act_T) then + Error_Msg_N + ("actual of synchronized type must be tagged", Actual); + Abandon_Instantiation (Actual); + + elsif Nkind (Parent (Act_T)) = N_Full_Type_Declaration + and then Nkind (Type_Definition (Parent (Act_T))) = + N_Derived_Type_Definition + and then not Synchronized_Present (Type_Definition + (Parent (Act_T))) + then + Error_Msg_N + ("actual of synchronized type must be synchronized", Actual); + Abandon_Instantiation (Actual); + end if; + end if; + + -- Perform atomic/volatile checks (RM C.6(12)). Note that AI05-0218-1 + -- removes the second instance of the phrase "or allow pass by copy". + + if Is_Atomic (Act_T) and then not Is_Atomic (Ancestor) then + Error_Msg_N + ("cannot have atomic actual type for non-atomic formal type", + Actual); + + elsif Is_Volatile (Act_T) and then not Is_Volatile (Ancestor) then + Error_Msg_N + ("cannot have volatile actual type for non-volatile formal type", + Actual); + end if; + + -- It should not be necessary to check for unknown discriminants on + -- Formal, but for some reason Has_Unknown_Discriminants is false for + -- A_Gen_T, so Is_Indefinite_Subtype incorrectly returns False. This + -- needs fixing. ??? + + if not Is_Indefinite_Subtype (A_Gen_T) + and then not Unknown_Discriminants_Present (Formal) + and then Is_Indefinite_Subtype (Act_T) + then + Error_Msg_N + ("actual subtype must be constrained", Actual); + Abandon_Instantiation (Actual); + end if; + + if not Unknown_Discriminants_Present (Formal) then + if Is_Constrained (Ancestor) then + if not Is_Constrained (Act_T) then + Error_Msg_N + ("actual subtype must be constrained", Actual); + Abandon_Instantiation (Actual); + end if; + + -- Ancestor is unconstrained, Check if generic formal and actual + -- agree on constrainedness. The check only applies to array types + -- and discriminated types. + + elsif Is_Constrained (Act_T) then + if Ekind (Ancestor) = E_Access_Type + or else + (not Is_Constrained (A_Gen_T) + and then Is_Composite_Type (A_Gen_T)) + then + Error_Msg_N + ("actual subtype must be unconstrained", Actual); + Abandon_Instantiation (Actual); + end if; + + -- A class-wide type is only allowed if the formal has unknown + -- discriminants. + + elsif Is_Class_Wide_Type (Act_T) + and then not Has_Unknown_Discriminants (Ancestor) + then + Error_Msg_NE + ("actual for & cannot be a class-wide type", Actual, Gen_T); + Abandon_Instantiation (Actual); + + -- Otherwise, the formal and actual shall have the same number + -- of discriminants and each discriminant of the actual must + -- correspond to a discriminant of the formal. + + elsif Has_Discriminants (Act_T) + and then not Has_Unknown_Discriminants (Act_T) + and then Has_Discriminants (Ancestor) + then + Actual_Discr := First_Discriminant (Act_T); + Ancestor_Discr := First_Discriminant (Ancestor); + while Present (Actual_Discr) + and then Present (Ancestor_Discr) + loop + if Base_Type (Act_T) /= Base_Type (Ancestor) and then + No (Corresponding_Discriminant (Actual_Discr)) + then + Error_Msg_NE + ("discriminant & does not correspond " & + "to ancestor discriminant", Actual, Actual_Discr); + Abandon_Instantiation (Actual); + end if; + + Next_Discriminant (Actual_Discr); + Next_Discriminant (Ancestor_Discr); + end loop; + + if Present (Actual_Discr) or else Present (Ancestor_Discr) then + Error_Msg_NE + ("actual for & must have same number of discriminants", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + -- This case should be caught by the earlier check for + -- constrainedness, but the check here is added for completeness. + + elsif Has_Discriminants (Act_T) + and then not Has_Unknown_Discriminants (Act_T) + then + Error_Msg_NE + ("actual for & must not have discriminants", Actual, Gen_T); + Abandon_Instantiation (Actual); + + elsif Has_Discriminants (Ancestor) then + Error_Msg_NE + ("actual for & must have known discriminants", Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + if not Subtypes_Statically_Compatible + (Act_T, Ancestor, Formal_Derived_Matching => True) + then + Error_Msg_N + ("constraint on actual is incompatible with formal", Actual); + Abandon_Instantiation (Actual); + end if; + end if; + + -- If the formal and actual types are abstract, check that there + -- are no abstract primitives of the actual type that correspond to + -- nonabstract primitives of the formal type (second sentence of + -- RM95-3.9.3(9)). + + if Is_Abstract_Type (A_Gen_T) and then Is_Abstract_Type (Act_T) then + Check_Abstract_Primitives : declare + Gen_Prims : constant Elist_Id := + Primitive_Operations (A_Gen_T); + Gen_Elmt : Elmt_Id; + Gen_Subp : Entity_Id; + Anc_Subp : Entity_Id; + Anc_Formal : Entity_Id; + Anc_F_Type : Entity_Id; + + Act_Prims : constant Elist_Id := Primitive_Operations (Act_T); + Act_Elmt : Elmt_Id; + Act_Subp : Entity_Id; + Act_Formal : Entity_Id; + Act_F_Type : Entity_Id; + + Subprograms_Correspond : Boolean; + + function Is_Tagged_Ancestor (T1, T2 : Entity_Id) return Boolean; + -- Returns true if T2 is derived directly or indirectly from + -- T1, including derivations from interfaces. T1 and T2 are + -- required to be specific tagged base types. + + ------------------------ + -- Is_Tagged_Ancestor -- + ------------------------ + + function Is_Tagged_Ancestor (T1, T2 : Entity_Id) return Boolean + is + Intfc_Elmt : Elmt_Id; + + begin + -- The predicate is satisfied if the types are the same + + if T1 = T2 then + return True; + + -- If we've reached the top of the derivation chain then + -- we know that T1 is not an ancestor of T2. + + elsif Etype (T2) = T2 then + return False; + + -- Proceed to check T2's immediate parent + + elsif Is_Ancestor (T1, Base_Type (Etype (T2))) then + return True; + + -- Finally, check to see if T1 is an ancestor of any of T2's + -- progenitors. + + else + Intfc_Elmt := First_Elmt (Interfaces (T2)); + while Present (Intfc_Elmt) loop + if Is_Ancestor (T1, Node (Intfc_Elmt)) then + return True; + end if; + + Next_Elmt (Intfc_Elmt); + end loop; + end if; + + return False; + end Is_Tagged_Ancestor; + + -- Start of processing for Check_Abstract_Primitives + + begin + -- Loop over all of the formal derived type's primitives + + Gen_Elmt := First_Elmt (Gen_Prims); + while Present (Gen_Elmt) loop + Gen_Subp := Node (Gen_Elmt); + + -- If the primitive of the formal is not abstract, then + -- determine whether there is a corresponding primitive of + -- the actual type that's abstract. + + if not Is_Abstract_Subprogram (Gen_Subp) then + Act_Elmt := First_Elmt (Act_Prims); + while Present (Act_Elmt) loop + Act_Subp := Node (Act_Elmt); + + -- If we find an abstract primitive of the actual, + -- then we need to test whether it corresponds to the + -- subprogram from which the generic formal primitive + -- is inherited. + + if Is_Abstract_Subprogram (Act_Subp) then + Anc_Subp := Alias (Gen_Subp); + + -- Test whether we have a corresponding primitive + -- by comparing names, kinds, formal types, and + -- result types. + + if Chars (Anc_Subp) = Chars (Act_Subp) + and then Ekind (Anc_Subp) = Ekind (Act_Subp) + then + Anc_Formal := First_Formal (Anc_Subp); + Act_Formal := First_Formal (Act_Subp); + while Present (Anc_Formal) + and then Present (Act_Formal) + loop + Anc_F_Type := Etype (Anc_Formal); + Act_F_Type := Etype (Act_Formal); + + if Ekind (Anc_F_Type) + = E_Anonymous_Access_Type + then + Anc_F_Type := Designated_Type (Anc_F_Type); + + if Ekind (Act_F_Type) + = E_Anonymous_Access_Type + then + Act_F_Type := + Designated_Type (Act_F_Type); + else + exit; + end if; + + elsif + Ekind (Act_F_Type) = E_Anonymous_Access_Type + then + exit; + end if; + + Anc_F_Type := Base_Type (Anc_F_Type); + Act_F_Type := Base_Type (Act_F_Type); + + -- If the formal is controlling, then the + -- the type of the actual primitive's formal + -- must be derived directly or indirectly + -- from the type of the ancestor primitive's + -- formal. + + if Is_Controlling_Formal (Anc_Formal) then + if not Is_Tagged_Ancestor + (Anc_F_Type, Act_F_Type) + then + exit; + end if; + + -- Otherwise the types of the formals must + -- be the same. + + elsif Anc_F_Type /= Act_F_Type then + exit; + end if; + + Next_Entity (Anc_Formal); + Next_Entity (Act_Formal); + end loop; + + -- If we traversed through all of the formals + -- then so far the subprograms correspond, so + -- now check that any result types correspond. + + if No (Anc_Formal) and then No (Act_Formal) then + Subprograms_Correspond := True; + + if Ekind (Act_Subp) = E_Function then + Anc_F_Type := Etype (Anc_Subp); + Act_F_Type := Etype (Act_Subp); + + if Ekind (Anc_F_Type) + = E_Anonymous_Access_Type + then + Anc_F_Type := + Designated_Type (Anc_F_Type); + + if Ekind (Act_F_Type) + = E_Anonymous_Access_Type + then + Act_F_Type := + Designated_Type (Act_F_Type); + else + Subprograms_Correspond := False; + end if; + + elsif + Ekind (Act_F_Type) + = E_Anonymous_Access_Type + then + Subprograms_Correspond := False; + end if; + + Anc_F_Type := Base_Type (Anc_F_Type); + Act_F_Type := Base_Type (Act_F_Type); + + -- Now either the result types must be + -- the same or, if the result type is + -- controlling, the result type of the + -- actual primitive must descend from the + -- result type of the ancestor primitive. + + if Subprograms_Correspond + and then Anc_F_Type /= Act_F_Type + and then + Has_Controlling_Result (Anc_Subp) + and then + not Is_Tagged_Ancestor + (Anc_F_Type, Act_F_Type) + then + Subprograms_Correspond := False; + end if; + end if; + + -- Found a matching subprogram belonging to + -- formal ancestor type, so actual subprogram + -- corresponds and this violates 3.9.3(9). + + if Subprograms_Correspond then + Error_Msg_NE + ("abstract subprogram & overrides " & + "nonabstract subprogram of ancestor", + Actual, + Act_Subp); + end if; + end if; + end if; + end if; + + Next_Elmt (Act_Elmt); + end loop; + end if; + + Next_Elmt (Gen_Elmt); + end loop; + end Check_Abstract_Primitives; + end if; + + -- Verify that limitedness matches. If parent is a limited + -- interface then the generic formal is not unless declared + -- explicitly so. If not declared limited, the actual cannot be + -- limited (see AI05-0087). + + -- Even though this AI is a binding interpretation, we enable the + -- check only in Ada 2012 mode, because this improper construct + -- shows up in user code and in existing B-tests. + + if Is_Limited_Type (Act_T) + and then not Is_Limited_Type (A_Gen_T) + and then Ada_Version >= Ada_2012 + then + if In_Instance then + null; + else + Error_Msg_NE + ("actual for non-limited & cannot be a limited type", Actual, + Gen_T); + Explain_Limited_Type (Act_T, Actual); + Abandon_Instantiation (Actual); + end if; + end if; + end Validate_Derived_Type_Instance; + + ---------------------------------------- + -- Validate_Discriminated_Formal_Type -- + ---------------------------------------- + + procedure Validate_Discriminated_Formal_Type is + Formal_Discr : Entity_Id; + Actual_Discr : Entity_Id; + Formal_Subt : Entity_Id; + + begin + if Has_Discriminants (A_Gen_T) then + if not Has_Discriminants (Act_T) then + Error_Msg_NE + ("actual for & must have discriminants", Actual, Gen_T); + Abandon_Instantiation (Actual); + + elsif Is_Constrained (Act_T) then + Error_Msg_NE + ("actual for & must be unconstrained", Actual, Gen_T); + Abandon_Instantiation (Actual); + + else + Formal_Discr := First_Discriminant (A_Gen_T); + Actual_Discr := First_Discriminant (Act_T); + while Formal_Discr /= Empty loop + if Actual_Discr = Empty then + Error_Msg_NE + ("discriminants on actual do not match formal", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + Formal_Subt := Get_Instance_Of (Etype (Formal_Discr)); + + -- Access discriminants match if designated types do + + if Ekind (Base_Type (Formal_Subt)) = E_Anonymous_Access_Type + and then (Ekind (Base_Type (Etype (Actual_Discr)))) = + E_Anonymous_Access_Type + and then + Get_Instance_Of + (Designated_Type (Base_Type (Formal_Subt))) = + Designated_Type (Base_Type (Etype (Actual_Discr))) + then + null; + + elsif Base_Type (Formal_Subt) /= + Base_Type (Etype (Actual_Discr)) + then + Error_Msg_NE + ("types of actual discriminants must match formal", + Actual, Gen_T); + Abandon_Instantiation (Actual); + + elsif not Subtypes_Statically_Match + (Formal_Subt, Etype (Actual_Discr)) + and then Ada_Version >= Ada_95 + then + Error_Msg_NE + ("subtypes of actual discriminants must match formal", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + Next_Discriminant (Formal_Discr); + Next_Discriminant (Actual_Discr); + end loop; + + if Actual_Discr /= Empty then + Error_Msg_NE + ("discriminants on actual do not match formal", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + end if; + end if; + end Validate_Discriminated_Formal_Type; + + --------------------------------------- + -- Validate_Incomplete_Type_Instance -- + --------------------------------------- + + procedure Validate_Incomplete_Type_Instance is + begin + if not Is_Tagged_Type (Act_T) + and then Is_Tagged_Type (A_Gen_T) + then + Error_Msg_NE + ("actual for & must be a tagged type", Actual, Gen_T); + end if; + + Validate_Discriminated_Formal_Type; + end Validate_Incomplete_Type_Instance; + + -------------------------------------- + -- Validate_Interface_Type_Instance -- + -------------------------------------- + + procedure Validate_Interface_Type_Instance is + begin + if not Is_Interface (Act_T) then + Error_Msg_NE + ("actual for formal interface type must be an interface", + Actual, Gen_T); + + elsif Is_Limited_Type (Act_T) /= Is_Limited_Type (A_Gen_T) + or else + Is_Task_Interface (A_Gen_T) /= Is_Task_Interface (Act_T) + or else + Is_Protected_Interface (A_Gen_T) /= + Is_Protected_Interface (Act_T) + or else + Is_Synchronized_Interface (A_Gen_T) /= + Is_Synchronized_Interface (Act_T) + then + Error_Msg_NE + ("actual for interface& does not match (RM 12.5.5(4))", + Actual, Gen_T); + end if; + end Validate_Interface_Type_Instance; + + ------------------------------------ + -- Validate_Private_Type_Instance -- + ------------------------------------ + + procedure Validate_Private_Type_Instance is + begin + if Is_Limited_Type (Act_T) + and then not Is_Limited_Type (A_Gen_T) + then + if In_Instance then + null; + else + Error_Msg_NE + ("actual for non-limited & cannot be a limited type", Actual, + Gen_T); + Explain_Limited_Type (Act_T, Actual); + Abandon_Instantiation (Actual); + end if; + + elsif Known_To_Have_Preelab_Init (A_Gen_T) + and then not Has_Preelaborable_Initialization (Act_T) + then + Error_Msg_NE + ("actual for & must have preelaborable initialization", Actual, + Gen_T); + + elsif Is_Indefinite_Subtype (Act_T) + and then not Is_Indefinite_Subtype (A_Gen_T) + and then Ada_Version >= Ada_95 + then + Error_Msg_NE + ("actual for & must be a definite subtype", Actual, Gen_T); + + elsif not Is_Tagged_Type (Act_T) + and then Is_Tagged_Type (A_Gen_T) + then + Error_Msg_NE + ("actual for & must be a tagged type", Actual, Gen_T); + end if; + + Validate_Discriminated_Formal_Type; + Ancestor := Gen_T; + end Validate_Private_Type_Instance; + + -- Start of processing for Instantiate_Type + + begin + if Get_Instance_Of (A_Gen_T) /= A_Gen_T then + Error_Msg_N ("duplicate instantiation of generic type", Actual); + return New_List (Error); + + elsif not Is_Entity_Name (Actual) + or else not Is_Type (Entity (Actual)) + then + Error_Msg_NE + ("expect valid subtype mark to instantiate &", Actual, Gen_T); + Abandon_Instantiation (Actual); + + else + Act_T := Entity (Actual); + + -- Ada 2005 (AI-216): An Unchecked_Union subtype shall only be passed + -- as a generic actual parameter if the corresponding formal type + -- does not have a known_discriminant_part, or is a formal derived + -- type that is an Unchecked_Union type. + + if Is_Unchecked_Union (Base_Type (Act_T)) then + if not Has_Discriminants (A_Gen_T) + or else + (Is_Derived_Type (A_Gen_T) + and then + Is_Unchecked_Union (A_Gen_T)) + then + null; + else + Error_Msg_N ("unchecked union cannot be the actual for a" & + " discriminated formal type", Act_T); + + end if; + end if; + + -- Deal with fixed/floating restrictions + + if Is_Floating_Point_Type (Act_T) then + Check_Restriction (No_Floating_Point, Actual); + elsif Is_Fixed_Point_Type (Act_T) then + Check_Restriction (No_Fixed_Point, Actual); + end if; + + -- Deal with error of using incomplete type as generic actual. + -- This includes limited views of a type, even if the non-limited + -- view may be available. + + if Ekind (Act_T) = E_Incomplete_Type + or else (Is_Class_Wide_Type (Act_T) + and then + Ekind (Root_Type (Act_T)) = E_Incomplete_Type) + then + -- If the formal is an incomplete type, the actual can be + -- incomplete as well. + + if Ekind (A_Gen_T) = E_Incomplete_Type then + null; + + elsif Is_Class_Wide_Type (Act_T) + or else No (Full_View (Act_T)) + then + Error_Msg_N ("premature use of incomplete type", Actual); + Abandon_Instantiation (Actual); + else + Act_T := Full_View (Act_T); + Set_Entity (Actual, Act_T); + + if Has_Private_Component (Act_T) then + Error_Msg_N + ("premature use of type with private component", Actual); + end if; + end if; + + -- Deal with error of premature use of private type as generic actual + + elsif Is_Private_Type (Act_T) + and then Is_Private_Type (Base_Type (Act_T)) + and then not Is_Generic_Type (Act_T) + and then not Is_Derived_Type (Act_T) + and then No (Full_View (Root_Type (Act_T))) + then + -- If the formal is an incomplete type, the actual can be + -- private or incomplete as well. + + if Ekind (A_Gen_T) = E_Incomplete_Type then + null; + else + Error_Msg_N ("premature use of private type", Actual); + end if; + + elsif Has_Private_Component (Act_T) then + Error_Msg_N + ("premature use of type with private component", Actual); + end if; + + Set_Instance_Of (A_Gen_T, Act_T); + + -- If the type is generic, the class-wide type may also be used + + if Is_Tagged_Type (A_Gen_T) + and then Is_Tagged_Type (Act_T) + and then not Is_Class_Wide_Type (A_Gen_T) + then + Set_Instance_Of (Class_Wide_Type (A_Gen_T), + Class_Wide_Type (Act_T)); + end if; + + if not Is_Abstract_Type (A_Gen_T) + and then Is_Abstract_Type (Act_T) + then + Error_Msg_N + ("actual of non-abstract formal cannot be abstract", Actual); + end if; + + -- A generic scalar type is a first subtype for which we generate + -- an anonymous base type. Indicate that the instance of this base + -- is the base type of the actual. + + if Is_Scalar_Type (A_Gen_T) then + Set_Instance_Of (Etype (A_Gen_T), Etype (Act_T)); + end if; + end if; + + if Error_Posted (Act_T) then + null; + else + case Nkind (Def) is + when N_Formal_Private_Type_Definition => + Validate_Private_Type_Instance; + + when N_Formal_Incomplete_Type_Definition => + Validate_Incomplete_Type_Instance; + + when N_Formal_Derived_Type_Definition => + Validate_Derived_Type_Instance; + + when N_Formal_Discrete_Type_Definition => + if not Is_Discrete_Type (Act_T) then + Error_Msg_NE + ("expect discrete type in instantiation of&", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + when N_Formal_Signed_Integer_Type_Definition => + if not Is_Signed_Integer_Type (Act_T) then + Error_Msg_NE + ("expect signed integer type in instantiation of&", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + when N_Formal_Modular_Type_Definition => + if not Is_Modular_Integer_Type (Act_T) then + Error_Msg_NE + ("expect modular type in instantiation of &", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + when N_Formal_Floating_Point_Definition => + if not Is_Floating_Point_Type (Act_T) then + Error_Msg_NE + ("expect float type in instantiation of &", Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + when N_Formal_Ordinary_Fixed_Point_Definition => + if not Is_Ordinary_Fixed_Point_Type (Act_T) then + Error_Msg_NE + ("expect ordinary fixed point type in instantiation of &", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + when N_Formal_Decimal_Fixed_Point_Definition => + if not Is_Decimal_Fixed_Point_Type (Act_T) then + Error_Msg_NE + ("expect decimal type in instantiation of &", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + when N_Array_Type_Definition => + Validate_Array_Type_Instance; + + when N_Access_To_Object_Definition => + Validate_Access_Type_Instance; + + when N_Access_Function_Definition | + N_Access_Procedure_Definition => + Validate_Access_Subprogram_Instance; + + when N_Record_Definition => + Validate_Interface_Type_Instance; + + when N_Derived_Type_Definition => + Validate_Derived_Interface_Type_Instance; + + when others => + raise Program_Error; + + end case; + end if; + + Subt := New_Copy (Gen_T); + + -- Use adjusted sloc of subtype name as the location for other nodes in + -- the subtype declaration. + + Loc := Sloc (Subt); + + Decl_Node := + Make_Subtype_Declaration (Loc, + Defining_Identifier => Subt, + Subtype_Indication => New_Occurrence_Of (Act_T, Loc)); + + if Is_Private_Type (Act_T) then + Set_Has_Private_View (Subtype_Indication (Decl_Node)); + + elsif Is_Access_Type (Act_T) + and then Is_Private_Type (Designated_Type (Act_T)) + then + Set_Has_Private_View (Subtype_Indication (Decl_Node)); + end if; + + Decl_Nodes := New_List (Decl_Node); + + -- Flag actual derived types so their elaboration produces the + -- appropriate renamings for the primitive operations of the ancestor. + -- Flag actual for formal private types as well, to determine whether + -- operations in the private part may override inherited operations. + -- If the formal has an interface list, the ancestor is not the + -- parent, but the analyzed formal that includes the interface + -- operations of all its progenitors. + + -- Same treatment for formal private types, so we can check whether the + -- type is tagged limited when validating derivations in the private + -- part. (See AI05-096). + + if Nkind (Def) = N_Formal_Derived_Type_Definition then + if Present (Interface_List (Def)) then + Set_Generic_Parent_Type (Decl_Node, A_Gen_T); + else + Set_Generic_Parent_Type (Decl_Node, Ancestor); + end if; + + elsif Nkind_In (Def, + N_Formal_Private_Type_Definition, + N_Formal_Incomplete_Type_Definition) + then + Set_Generic_Parent_Type (Decl_Node, A_Gen_T); + end if; + + -- If the actual is a synchronized type that implements an interface, + -- the primitive operations are attached to the corresponding record, + -- and we have to treat it as an additional generic actual, so that its + -- primitive operations become visible in the instance. The task or + -- protected type itself does not carry primitive operations. + + if Is_Concurrent_Type (Act_T) + and then Is_Tagged_Type (Act_T) + and then Present (Corresponding_Record_Type (Act_T)) + and then Present (Ancestor) + and then Is_Interface (Ancestor) + then + declare + Corr_Rec : constant Entity_Id := + Corresponding_Record_Type (Act_T); + New_Corr : Entity_Id; + Corr_Decl : Node_Id; + + begin + New_Corr := Make_Temporary (Loc, 'S'); + Corr_Decl := + Make_Subtype_Declaration (Loc, + Defining_Identifier => New_Corr, + Subtype_Indication => + New_Occurrence_Of (Corr_Rec, Loc)); + Append_To (Decl_Nodes, Corr_Decl); + + if Ekind (Act_T) = E_Task_Type then + Set_Ekind (Subt, E_Task_Subtype); + else + Set_Ekind (Subt, E_Protected_Subtype); + end if; + + Set_Corresponding_Record_Type (Subt, Corr_Rec); + Set_Generic_Parent_Type (Corr_Decl, Ancestor); + Set_Generic_Parent_Type (Decl_Node, Empty); + end; + end if; + + return Decl_Nodes; + end Instantiate_Type; + + --------------------- + -- Is_In_Main_Unit -- + --------------------- + + function Is_In_Main_Unit (N : Node_Id) return Boolean is + Unum : constant Unit_Number_Type := Get_Source_Unit (N); + Current_Unit : Node_Id; + + begin + if Unum = Main_Unit then + return True; + + -- If the current unit is a subunit then it is either the main unit or + -- is being compiled as part of the main unit. + + elsif Nkind (N) = N_Compilation_Unit then + return Nkind (Unit (N)) = N_Subunit; + end if; + + Current_Unit := Parent (N); + while Present (Current_Unit) + and then Nkind (Current_Unit) /= N_Compilation_Unit + loop + Current_Unit := Parent (Current_Unit); + end loop; + + -- The instantiation node is in the main unit, or else the current node + -- (perhaps as the result of nested instantiations) is in the main unit, + -- or in the declaration of the main unit, which in this last case must + -- be a body. + + return Unum = Main_Unit + or else Current_Unit = Cunit (Main_Unit) + or else Current_Unit = Library_Unit (Cunit (Main_Unit)) + or else (Present (Library_Unit (Current_Unit)) + and then Is_In_Main_Unit (Library_Unit (Current_Unit))); + end Is_In_Main_Unit; + + ---------------------------- + -- Load_Parent_Of_Generic -- + ---------------------------- + + procedure Load_Parent_Of_Generic + (N : Node_Id; + Spec : Node_Id; + Body_Optional : Boolean := False) + is + Comp_Unit : constant Node_Id := Cunit (Get_Source_Unit (Spec)); + Saved_Style_Check : constant Boolean := Style_Check; + Saved_Warnings : constant Warning_Record := Save_Warnings; + True_Parent : Node_Id; + Inst_Node : Node_Id; + OK : Boolean; + Previous_Instances : constant Elist_Id := New_Elmt_List; + + procedure Collect_Previous_Instances (Decls : List_Id); + -- Collect all instantiations in the given list of declarations, that + -- precede the generic that we need to load. If the bodies of these + -- instantiations are available, we must analyze them, to ensure that + -- the public symbols generated are the same when the unit is compiled + -- to generate code, and when it is compiled in the context of a unit + -- that needs a particular nested instance. This process is applied to + -- both package and subprogram instances. + + -------------------------------- + -- Collect_Previous_Instances -- + -------------------------------- + + procedure Collect_Previous_Instances (Decls : List_Id) is + Decl : Node_Id; + + begin + Decl := First (Decls); + while Present (Decl) loop + if Sloc (Decl) >= Sloc (Inst_Node) then + return; + + -- If Decl is an instantiation, then record it as requiring + -- instantiation of the corresponding body, except if it is an + -- abbreviated instantiation generated internally for conformance + -- checking purposes only for the case of a formal package + -- declared without a box (see Instantiate_Formal_Package). Such + -- an instantiation does not generate any code (the actual code + -- comes from actual) and thus does not need to be analyzed here. + -- If the instantiation appears with a generic package body it is + -- not analyzed here either. + + elsif Nkind (Decl) = N_Package_Instantiation + and then not Is_Internal (Defining_Entity (Decl)) + then + Append_Elmt (Decl, Previous_Instances); + + -- For a subprogram instantiation, omit instantiations intrinsic + -- operations (Unchecked_Conversions, etc.) that have no bodies. + + elsif Nkind_In (Decl, N_Function_Instantiation, + N_Procedure_Instantiation) + and then not Is_Intrinsic_Subprogram (Entity (Name (Decl))) + then + Append_Elmt (Decl, Previous_Instances); + + elsif Nkind (Decl) = N_Package_Declaration then + Collect_Previous_Instances + (Visible_Declarations (Specification (Decl))); + Collect_Previous_Instances + (Private_Declarations (Specification (Decl))); + + -- Previous non-generic bodies may contain instances as well + + elsif Nkind (Decl) = N_Package_Body + and then Ekind (Corresponding_Spec (Decl)) /= E_Generic_Package + then + Collect_Previous_Instances (Declarations (Decl)); + + elsif Nkind (Decl) = N_Subprogram_Body + and then not Acts_As_Spec (Decl) + and then not Is_Generic_Subprogram (Corresponding_Spec (Decl)) + then + Collect_Previous_Instances (Declarations (Decl)); + end if; + + Next (Decl); + end loop; + end Collect_Previous_Instances; + + -- Start of processing for Load_Parent_Of_Generic + + begin + if not In_Same_Source_Unit (N, Spec) + or else Nkind (Unit (Comp_Unit)) = N_Package_Declaration + or else (Nkind (Unit (Comp_Unit)) = N_Package_Body + and then not Is_In_Main_Unit (Spec)) + then + -- Find body of parent of spec, and analyze it. A special case arises + -- when the parent is an instantiation, that is to say when we are + -- currently instantiating a nested generic. In that case, there is + -- no separate file for the body of the enclosing instance. Instead, + -- the enclosing body must be instantiated as if it were a pending + -- instantiation, in order to produce the body for the nested generic + -- we require now. Note that in that case the generic may be defined + -- in a package body, the instance defined in the same package body, + -- and the original enclosing body may not be in the main unit. + + Inst_Node := Empty; + + True_Parent := Parent (Spec); + while Present (True_Parent) + and then Nkind (True_Parent) /= N_Compilation_Unit + loop + if Nkind (True_Parent) = N_Package_Declaration + and then + Nkind (Original_Node (True_Parent)) = N_Package_Instantiation + then + -- Parent is a compilation unit that is an instantiation. + -- Instantiation node has been replaced with package decl. + + Inst_Node := Original_Node (True_Parent); + exit; + + elsif Nkind (True_Parent) = N_Package_Declaration + and then Present (Generic_Parent (Specification (True_Parent))) + and then Nkind (Parent (True_Parent)) /= N_Compilation_Unit + then + -- Parent is an instantiation within another specification. + -- Declaration for instance has been inserted before original + -- instantiation node. A direct link would be preferable? + + Inst_Node := Next (True_Parent); + while Present (Inst_Node) + and then Nkind (Inst_Node) /= N_Package_Instantiation + loop + Next (Inst_Node); + end loop; + + -- If the instance appears within a generic, and the generic + -- unit is defined within a formal package of the enclosing + -- generic, there is no generic body available, and none + -- needed. A more precise test should be used ??? + + if No (Inst_Node) then + return; + end if; + + exit; + + else + True_Parent := Parent (True_Parent); + end if; + end loop; + + -- Case where we are currently instantiating a nested generic + + if Present (Inst_Node) then + if Nkind (Parent (True_Parent)) = N_Compilation_Unit then + + -- Instantiation node and declaration of instantiated package + -- were exchanged when only the declaration was needed. + -- Restore instantiation node before proceeding with body. + + Set_Unit (Parent (True_Parent), Inst_Node); + end if; + + -- Now complete instantiation of enclosing body, if it appears in + -- some other unit. If it appears in the current unit, the body + -- will have been instantiated already. + + if No (Corresponding_Body (Instance_Spec (Inst_Node))) then + + -- We need to determine the expander mode to instantiate the + -- enclosing body. Because the generic body we need may use + -- global entities declared in the enclosing package (including + -- aggregates) it is in general necessary to compile this body + -- with expansion enabled, except if we are within a generic + -- package, in which case the usual generic rule applies. + + declare + Exp_Status : Boolean := True; + Scop : Entity_Id; + + begin + -- Loop through scopes looking for generic package + + Scop := Scope (Defining_Entity (Instance_Spec (Inst_Node))); + while Present (Scop) + and then Scop /= Standard_Standard + loop + if Ekind (Scop) = E_Generic_Package then + Exp_Status := False; + exit; + end if; + + Scop := Scope (Scop); + end loop; + + -- Collect previous instantiations in the unit that contains + -- the desired generic. + + if Nkind (Parent (True_Parent)) /= N_Compilation_Unit + and then not Body_Optional + then + declare + Decl : Elmt_Id; + Info : Pending_Body_Info; + Par : Node_Id; + + begin + Par := Parent (Inst_Node); + while Present (Par) loop + exit when Nkind (Parent (Par)) = N_Compilation_Unit; + Par := Parent (Par); + end loop; + + pragma Assert (Present (Par)); + + if Nkind (Par) = N_Package_Body then + Collect_Previous_Instances (Declarations (Par)); + + elsif Nkind (Par) = N_Package_Declaration then + Collect_Previous_Instances + (Visible_Declarations (Specification (Par))); + Collect_Previous_Instances + (Private_Declarations (Specification (Par))); + + else + -- Enclosing unit is a subprogram body. In this + -- case all instance bodies are processed in order + -- and there is no need to collect them separately. + + null; + end if; + + Decl := First_Elmt (Previous_Instances); + while Present (Decl) loop + Info := + (Inst_Node => Node (Decl), + Act_Decl => + Instance_Spec (Node (Decl)), + Expander_Status => Exp_Status, + Current_Sem_Unit => + Get_Code_Unit (Sloc (Node (Decl))), + Scope_Suppress => Scope_Suppress, + Local_Suppress_Stack_Top => + Local_Suppress_Stack_Top, + Version => Ada_Version, + Version_Pragma => Ada_Version_Pragma, + Warnings => Save_Warnings, + SPARK_Mode => SPARK_Mode, + SPARK_Mode_Pragma => SPARK_Mode_Pragma); + + -- Package instance + + if + Nkind (Node (Decl)) = N_Package_Instantiation + then + Instantiate_Package_Body + (Info, Body_Optional => True); + + -- Subprogram instance + + else + -- The instance_spec is the wrapper package, + -- and the subprogram declaration is the last + -- declaration in the wrapper. + + Info.Act_Decl := + Last + (Visible_Declarations + (Specification (Info.Act_Decl))); + + Instantiate_Subprogram_Body + (Info, Body_Optional => True); + end if; + + Next_Elmt (Decl); + end loop; + end; + end if; + + Instantiate_Package_Body + (Body_Info => + ((Inst_Node => Inst_Node, + Act_Decl => True_Parent, + Expander_Status => Exp_Status, + Current_Sem_Unit => Get_Code_Unit + (Sloc (Inst_Node)), + Scope_Suppress => Scope_Suppress, + Local_Suppress_Stack_Top => Local_Suppress_Stack_Top, + Version => Ada_Version, + Version_Pragma => Ada_Version_Pragma, + Warnings => Save_Warnings, + SPARK_Mode => SPARK_Mode, + SPARK_Mode_Pragma => SPARK_Mode_Pragma)), + Body_Optional => Body_Optional); + end; + end if; + + -- Case where we are not instantiating a nested generic + + else + Opt.Style_Check := False; + Expander_Mode_Save_And_Set (True); + Load_Needed_Body (Comp_Unit, OK); + Opt.Style_Check := Saved_Style_Check; + Restore_Warnings (Saved_Warnings); + Expander_Mode_Restore; + + if not OK + and then Unit_Requires_Body (Defining_Entity (Spec)) + and then not Body_Optional + then + declare + Bname : constant Unit_Name_Type := + Get_Body_Name (Get_Unit_Name (Unit (Comp_Unit))); + + begin + -- In CodePeer mode, the missing body may make the analysis + -- incomplete, but we do not treat it as fatal. + + if CodePeer_Mode then + return; + + else + Error_Msg_Unit_1 := Bname; + Error_Msg_N ("this instantiation requires$!", N); + Error_Msg_File_1 := + Get_File_Name (Bname, Subunit => False); + Error_Msg_N ("\but file{ was not found!", N); + raise Unrecoverable_Error; + end if; + end; + end if; + end if; + end if; + + -- If loading parent of the generic caused an instantiation circularity, + -- we abandon compilation at this point, because otherwise in some cases + -- we get into trouble with infinite recursions after this point. + + if Circularity_Detected then + raise Unrecoverable_Error; + end if; + end Load_Parent_Of_Generic; + + --------------------------------- + -- Map_Formal_Package_Entities -- + --------------------------------- + + procedure Map_Formal_Package_Entities (Form : Entity_Id; Act : Entity_Id) is + E1 : Entity_Id; + E2 : Entity_Id; + + begin + Set_Instance_Of (Form, Act); + + -- Traverse formal and actual package to map the corresponding entities. + -- We skip over internal entities that may be generated during semantic + -- analysis, and find the matching entities by name, given that they + -- must appear in the same order. + + E1 := First_Entity (Form); + E2 := First_Entity (Act); + while Present (E1) and then E1 /= First_Private_Entity (Form) loop + -- Could this test be a single condition??? Seems like it could, and + -- isn't FPE (Form) a constant anyway??? + + if not Is_Internal (E1) + and then Present (Parent (E1)) + and then not Is_Class_Wide_Type (E1) + and then not Is_Internal_Name (Chars (E1)) + then + while Present (E2) and then Chars (E2) /= Chars (E1) loop + Next_Entity (E2); + end loop; + + if No (E2) then + exit; + else + Set_Instance_Of (E1, E2); + + if Is_Type (E1) and then Is_Tagged_Type (E2) then + Set_Instance_Of (Class_Wide_Type (E1), Class_Wide_Type (E2)); + end if; + + if Is_Constrained (E1) then + Set_Instance_Of (Base_Type (E1), Base_Type (E2)); + end if; + + if Ekind (E1) = E_Package and then No (Renamed_Object (E1)) then + Map_Formal_Package_Entities (E1, E2); + end if; + end if; + end if; + + Next_Entity (E1); + end loop; + end Map_Formal_Package_Entities; + + ----------------------- + -- Move_Freeze_Nodes -- + ----------------------- + + procedure Move_Freeze_Nodes + (Out_Of : Entity_Id; + After : Node_Id; + L : List_Id) + is + Decl : Node_Id; + Next_Decl : Node_Id; + Next_Node : Node_Id := After; + Spec : Node_Id; + + function Is_Outer_Type (T : Entity_Id) return Boolean; + -- Check whether entity is declared in a scope external to that of the + -- generic unit. + + ------------------- + -- Is_Outer_Type -- + ------------------- + + function Is_Outer_Type (T : Entity_Id) return Boolean is + Scop : Entity_Id := Scope (T); + + begin + if Scope_Depth (Scop) < Scope_Depth (Out_Of) then + return True; + + else + while Scop /= Standard_Standard loop + if Scop = Out_Of then + return False; + else + Scop := Scope (Scop); + end if; + end loop; + + return True; + end if; + end Is_Outer_Type; + + -- Start of processing for Move_Freeze_Nodes + + begin + if No (L) then + return; + end if; + + -- First remove the freeze nodes that may appear before all other + -- declarations. + + Decl := First (L); + while Present (Decl) + and then Nkind (Decl) = N_Freeze_Entity + and then Is_Outer_Type (Entity (Decl)) + loop + Decl := Remove_Head (L); + Insert_After (Next_Node, Decl); + Set_Analyzed (Decl, False); + Next_Node := Decl; + Decl := First (L); + end loop; + + -- Next scan the list of declarations and remove each freeze node that + -- appears ahead of the current node. + + while Present (Decl) loop + while Present (Next (Decl)) + and then Nkind (Next (Decl)) = N_Freeze_Entity + and then Is_Outer_Type (Entity (Next (Decl))) + loop + Next_Decl := Remove_Next (Decl); + Insert_After (Next_Node, Next_Decl); + Set_Analyzed (Next_Decl, False); + Next_Node := Next_Decl; + end loop; + + -- If the declaration is a nested package or concurrent type, then + -- recurse. Nested generic packages will have been processed from the + -- inside out. + + case Nkind (Decl) is + when N_Package_Declaration => + Spec := Specification (Decl); + + when N_Task_Type_Declaration => + Spec := Task_Definition (Decl); + + when N_Protected_Type_Declaration => + Spec := Protected_Definition (Decl); + + when others => + Spec := Empty; + end case; + + if Present (Spec) then + Move_Freeze_Nodes (Out_Of, Next_Node, Visible_Declarations (Spec)); + Move_Freeze_Nodes (Out_Of, Next_Node, Private_Declarations (Spec)); + end if; + + Next (Decl); + end loop; + end Move_Freeze_Nodes; + + ---------------- + -- Next_Assoc -- + ---------------- + + function Next_Assoc (E : Assoc_Ptr) return Assoc_Ptr is + begin + return Generic_Renamings.Table (E).Next_In_HTable; + end Next_Assoc; + + ------------------------ + -- Preanalyze_Actuals -- + ------------------------ + + procedure Preanalyze_Actuals (N : Node_Id) is + Assoc : Node_Id; + Act : Node_Id; + Errs : constant Int := Serious_Errors_Detected; + + Cur : Entity_Id := Empty; + -- Current homograph of the instance name + + Vis : Boolean; + -- Saved visibility status of the current homograph + + begin + Assoc := First (Generic_Associations (N)); + + -- If the instance is a child unit, its name may hide an outer homonym, + -- so make it invisible to perform name resolution on the actuals. + + if Nkind (Defining_Unit_Name (N)) = N_Defining_Program_Unit_Name + and then Present + (Current_Entity (Defining_Identifier (Defining_Unit_Name (N)))) + then + Cur := Current_Entity (Defining_Identifier (Defining_Unit_Name (N))); + + if Is_Compilation_Unit (Cur) then + Vis := Is_Immediately_Visible (Cur); + Set_Is_Immediately_Visible (Cur, False); + else + Cur := Empty; + end if; + end if; + + while Present (Assoc) loop + if Nkind (Assoc) /= N_Others_Choice then + Act := Explicit_Generic_Actual_Parameter (Assoc); + + -- Within a nested instantiation, a defaulted actual is an empty + -- association, so nothing to analyze. If the subprogram actual + -- is an attribute, analyze prefix only, because actual is not a + -- complete attribute reference. + + -- If actual is an allocator, analyze expression only. The full + -- analysis can generate code, and if instance is a compilation + -- unit we have to wait until the package instance is installed + -- to have a proper place to insert this code. + + -- String literals may be operators, but at this point we do not + -- know whether the actual is a formal subprogram or a string. + + if No (Act) then + null; + + elsif Nkind (Act) = N_Attribute_Reference then + Analyze (Prefix (Act)); + + elsif Nkind (Act) = N_Explicit_Dereference then + Analyze (Prefix (Act)); + + elsif Nkind (Act) = N_Allocator then + declare + Expr : constant Node_Id := Expression (Act); + + begin + if Nkind (Expr) = N_Subtype_Indication then + Analyze (Subtype_Mark (Expr)); + + -- Analyze separately each discriminant constraint, when + -- given with a named association. + + declare + Constr : Node_Id; + + begin + Constr := First (Constraints (Constraint (Expr))); + while Present (Constr) loop + if Nkind (Constr) = N_Discriminant_Association then + Analyze (Expression (Constr)); + else + Analyze (Constr); + end if; + + Next (Constr); + end loop; + end; + + else + Analyze (Expr); + end if; + end; + + elsif Nkind (Act) /= N_Operator_Symbol then + Analyze (Act); + end if; + + -- Ensure that a ghost subprogram does not act as generic actual + + if Is_Entity_Name (Act) + and then Is_Ghost_Subprogram (Entity (Act)) + then + Error_Msg_N + ("ghost subprogram & cannot act as generic actual", Act); + Abandon_Instantiation (Act); + + elsif Errs /= Serious_Errors_Detected then + + -- Do a minimal analysis of the generic, to prevent spurious + -- warnings complaining about the generic being unreferenced, + -- before abandoning the instantiation. + + Analyze (Name (N)); + + if Is_Entity_Name (Name (N)) + and then Etype (Name (N)) /= Any_Type + then + Generate_Reference (Entity (Name (N)), Name (N)); + Set_Is_Instantiated (Entity (Name (N))); + end if; + + if Present (Cur) then + + -- For the case of a child instance hiding an outer homonym, + -- provide additional warning which might explain the error. + + Set_Is_Immediately_Visible (Cur, Vis); + Error_Msg_NE ("& hides outer unit with the same name??", + N, Defining_Unit_Name (N)); + end if; + + Abandon_Instantiation (Act); + end if; + end if; + + Next (Assoc); + end loop; + + if Present (Cur) then + Set_Is_Immediately_Visible (Cur, Vis); + end if; + end Preanalyze_Actuals; + + ------------------- + -- Remove_Parent -- + ------------------- + + procedure Remove_Parent (In_Body : Boolean := False) is + S : Entity_Id := Current_Scope; + -- S is the scope containing the instantiation just completed. The scope + -- stack contains the parent instances of the instantiation, followed by + -- the original S. + + Cur_P : Entity_Id; + E : Entity_Id; + P : Entity_Id; + Hidden : Elmt_Id; + + begin + -- After child instantiation is complete, remove from scope stack the + -- extra copy of the current scope, and then remove parent instances. + + if not In_Body then + Pop_Scope; + + while Current_Scope /= S loop + P := Current_Scope; + End_Package_Scope (Current_Scope); + + if In_Open_Scopes (P) then + E := First_Entity (P); + while Present (E) loop + Set_Is_Immediately_Visible (E, True); + Next_Entity (E); + end loop; + + -- If instantiation is declared in a block, it is the enclosing + -- scope that might be a parent instance. Note that only one + -- block can be involved, because the parent instances have + -- been installed within it. + + if Ekind (P) = E_Block then + Cur_P := Scope (P); + else + Cur_P := P; + end if; + + if Is_Generic_Instance (Cur_P) and then P /= Current_Scope then + -- We are within an instance of some sibling. Retain + -- visibility of parent, for proper subsequent cleanup, and + -- reinstall private declarations as well. + + Set_In_Private_Part (P); + Install_Private_Declarations (P); + end if; + + -- If the ultimate parent is a top-level unit recorded in + -- Instance_Parent_Unit, then reset its visibility to what it was + -- before instantiation. (It's not clear what the purpose is of + -- testing whether Scope (P) is In_Open_Scopes, but that test was + -- present before the ultimate parent test was added.???) + + elsif not In_Open_Scopes (Scope (P)) + or else (P = Instance_Parent_Unit + and then not Parent_Unit_Visible) + then + Set_Is_Immediately_Visible (P, False); + + -- If the current scope is itself an instantiation of a generic + -- nested within P, and we are in the private part of body of this + -- instantiation, restore the full views of P, that were removed + -- in End_Package_Scope above. This obscure case can occur when a + -- subunit of a generic contains an instance of a child unit of + -- its generic parent unit. + + elsif S = Current_Scope and then Is_Generic_Instance (S) then + declare + Par : constant Entity_Id := + Generic_Parent (Package_Specification (S)); + begin + if Present (Par) + and then P = Scope (Par) + and then (In_Package_Body (S) or else In_Private_Part (S)) + then + Set_In_Private_Part (P); + Install_Private_Declarations (P); + end if; + end; + end if; + end loop; + + -- Reset visibility of entities in the enclosing scope + + Set_Is_Hidden_Open_Scope (Current_Scope, False); + + Hidden := First_Elmt (Hidden_Entities); + while Present (Hidden) loop + Set_Is_Immediately_Visible (Node (Hidden), True); + Next_Elmt (Hidden); + end loop; + + else + -- Each body is analyzed separately, and there is no context that + -- needs preserving from one body instance to the next, so remove all + -- parent scopes that have been installed. + + while Present (S) loop + End_Package_Scope (S); + Set_Is_Immediately_Visible (S, False); + S := Current_Scope; + exit when S = Standard_Standard; + end loop; + end if; + end Remove_Parent; + + ----------------- + -- Restore_Env -- + ----------------- + + procedure Restore_Env is + Saved : Instance_Env renames Instance_Envs.Table (Instance_Envs.Last); + + begin + if No (Current_Instantiated_Parent.Act_Id) then + -- Restore environment after subprogram inlining + + Restore_Private_Views (Empty); + end if; + + Current_Instantiated_Parent := Saved.Instantiated_Parent; + Exchanged_Views := Saved.Exchanged_Views; + Hidden_Entities := Saved.Hidden_Entities; + Current_Sem_Unit := Saved.Current_Sem_Unit; + Parent_Unit_Visible := Saved.Parent_Unit_Visible; + Instance_Parent_Unit := Saved.Instance_Parent_Unit; + + Restore_Opt_Config_Switches (Saved.Switches); + + Instance_Envs.Decrement_Last; + end Restore_Env; + + --------------------------- + -- Restore_Private_Views -- + --------------------------- + + procedure Restore_Private_Views + (Pack_Id : Entity_Id; + Is_Package : Boolean := True) + is + M : Elmt_Id; + E : Entity_Id; + Typ : Entity_Id; + Dep_Elmt : Elmt_Id; + Dep_Typ : Node_Id; + + procedure Restore_Nested_Formal (Formal : Entity_Id); + -- Hide the generic formals of formal packages declared with box which + -- were reachable in the current instantiation. + + --------------------------- + -- Restore_Nested_Formal -- + --------------------------- + + procedure Restore_Nested_Formal (Formal : Entity_Id) is + Ent : Entity_Id; + + begin + if Present (Renamed_Object (Formal)) + and then Denotes_Formal_Package (Renamed_Object (Formal), True) + then + return; + + elsif Present (Associated_Formal_Package (Formal)) then + Ent := First_Entity (Formal); + while Present (Ent) loop + exit when Ekind (Ent) = E_Package + and then Renamed_Entity (Ent) = Renamed_Entity (Formal); + + Set_Is_Hidden (Ent); + Set_Is_Potentially_Use_Visible (Ent, False); + + -- If package, then recurse + + if Ekind (Ent) = E_Package then + Restore_Nested_Formal (Ent); + end if; + + Next_Entity (Ent); + end loop; + end if; + end Restore_Nested_Formal; + + -- Start of processing for Restore_Private_Views + + begin + M := First_Elmt (Exchanged_Views); + while Present (M) loop + Typ := Node (M); + + -- Subtypes of types whose views have been exchanged, and that are + -- defined within the instance, were not on the Private_Dependents + -- list on entry to the instance, so they have to be exchanged + -- explicitly now, in order to remain consistent with the view of the + -- parent type. + + if Ekind_In (Typ, E_Private_Type, + E_Limited_Private_Type, + E_Record_Type_With_Private) + then + Dep_Elmt := First_Elmt (Private_Dependents (Typ)); + while Present (Dep_Elmt) loop + Dep_Typ := Node (Dep_Elmt); + + if Scope (Dep_Typ) = Pack_Id + and then Present (Full_View (Dep_Typ)) + then + Replace_Elmt (Dep_Elmt, Full_View (Dep_Typ)); + Exchange_Declarations (Dep_Typ); + end if; + + Next_Elmt (Dep_Elmt); + end loop; + end if; + + Exchange_Declarations (Node (M)); + Next_Elmt (M); + end loop; + + if No (Pack_Id) then + return; + end if; + + -- Make the generic formal parameters private, and make the formal types + -- into subtypes of the actuals again. + + E := First_Entity (Pack_Id); + while Present (E) loop + Set_Is_Hidden (E, True); + + if Is_Type (E) + and then Nkind (Parent (E)) = N_Subtype_Declaration + then + -- If the actual for E is itself a generic actual type from + -- an enclosing instance, E is still a generic actual type + -- outside of the current instance. This matter when resolving + -- an overloaded call that may be ambiguous in the enclosing + -- instance, when two of its actuals coincide. + + if Is_Entity_Name (Subtype_Indication (Parent (E))) + and then Is_Generic_Actual_Type + (Entity (Subtype_Indication (Parent (E)))) + then + null; + else + Set_Is_Generic_Actual_Type (E, False); + end if; + + -- An unusual case of aliasing: the actual may also be directly + -- visible in the generic, and be private there, while it is fully + -- visible in the context of the instance. The internal subtype + -- is private in the instance but has full visibility like its + -- parent in the enclosing scope. This enforces the invariant that + -- the privacy status of all private dependents of a type coincide + -- with that of the parent type. This can only happen when a + -- generic child unit is instantiated within a sibling. + + if Is_Private_Type (E) + and then not Is_Private_Type (Etype (E)) + then + Exchange_Declarations (E); + end if; + + elsif Ekind (E) = E_Package then + + -- The end of the renaming list is the renaming of the generic + -- package itself. If the instance is a subprogram, all entities + -- in the corresponding package are renamings. If this entity is + -- a formal package, make its own formals private as well. The + -- actual in this case is itself the renaming of an instantiation. + -- If the entity is not a package renaming, it is the entity + -- created to validate formal package actuals: ignore it. + + -- If the actual is itself a formal package for the enclosing + -- generic, or the actual for such a formal package, it remains + -- visible on exit from the instance, and therefore nothing needs + -- to be done either, except to keep it accessible. + + if Is_Package and then Renamed_Object (E) = Pack_Id then + exit; + + elsif Nkind (Parent (E)) /= N_Package_Renaming_Declaration then + null; + + elsif + Denotes_Formal_Package (Renamed_Object (E), True, Pack_Id) + then + Set_Is_Hidden (E, False); + + else + declare + Act_P : constant Entity_Id := Renamed_Object (E); + Id : Entity_Id; + + begin + Id := First_Entity (Act_P); + while Present (Id) + and then Id /= First_Private_Entity (Act_P) + loop + exit when Ekind (Id) = E_Package + and then Renamed_Object (Id) = Act_P; + + Set_Is_Hidden (Id, True); + Set_Is_Potentially_Use_Visible (Id, In_Use (Act_P)); + + if Ekind (Id) = E_Package then + Restore_Nested_Formal (Id); + end if; + + Next_Entity (Id); + end loop; + end; + end if; + end if; + + Next_Entity (E); + end loop; + end Restore_Private_Views; + + -------------- + -- Save_Env -- + -------------- + + procedure Save_Env + (Gen_Unit : Entity_Id; + Act_Unit : Entity_Id) + is + begin + Init_Env; + Set_Instance_Env (Gen_Unit, Act_Unit); + end Save_Env; + + ---------------------------- + -- Save_Global_References -- + ---------------------------- + + procedure Save_Global_References (N : Node_Id) is + Gen_Scope : Entity_Id; + E : Entity_Id; + N2 : Node_Id; + + function Is_Global (E : Entity_Id) return Boolean; + -- Check whether entity is defined outside of generic unit. Examine the + -- scope of an entity, and the scope of the scope, etc, until we find + -- either Standard, in which case the entity is global, or the generic + -- unit itself, which indicates that the entity is local. If the entity + -- is the generic unit itself, as in the case of a recursive call, or + -- the enclosing generic unit, if different from the current scope, then + -- it is local as well, because it will be replaced at the point of + -- instantiation. On the other hand, if it is a reference to a child + -- unit of a common ancestor, which appears in an instantiation, it is + -- global because it is used to denote a specific compilation unit at + -- the time the instantiations will be analyzed. + + procedure Reset_Entity (N : Node_Id); + -- Save semantic information on global entity so that it is not resolved + -- again at instantiation time. + + procedure Save_Entity_Descendants (N : Node_Id); + -- Apply Save_Global_References to the two syntactic descendants of + -- non-terminal nodes that carry an Associated_Node and are processed + -- through Reset_Entity. Once the global entity (if any) has been + -- captured together with its type, only two syntactic descendants need + -- to be traversed to complete the processing of the tree rooted at N. + -- This applies to Selected_Components, Expanded_Names, and to Operator + -- nodes. N can also be a character literal, identifier, or operator + -- symbol node, but the call has no effect in these cases. + + procedure Save_Global_Defaults (N1, N2 : Node_Id); + -- Default actuals in nested instances must be handled specially + -- because there is no link to them from the original tree. When an + -- actual subprogram is given by a default, we add an explicit generic + -- association for it in the instantiation node. When we save the + -- global references on the name of the instance, we recover the list + -- of generic associations, and add an explicit one to the original + -- generic tree, through which a global actual can be preserved. + -- Similarly, if a child unit is instantiated within a sibling, in the + -- context of the parent, we must preserve the identifier of the parent + -- so that it can be properly resolved in a subsequent instantiation. + + procedure Save_Global_Descendant (D : Union_Id); + -- Apply Save_Global_References recursively to the descendents of the + -- current node. + + procedure Save_References (N : Node_Id); + -- This is the recursive procedure that does the work, once the + -- enclosing generic scope has been established. + + --------------- + -- Is_Global -- + --------------- + + function Is_Global (E : Entity_Id) return Boolean is + Se : Entity_Id; + + function Is_Instance_Node (Decl : Node_Id) return Boolean; + -- Determine whether the parent node of a reference to a child unit + -- denotes an instantiation or a formal package, in which case the + -- reference to the child unit is global, even if it appears within + -- the current scope (e.g. when the instance appears within the body + -- of an ancestor). + + ---------------------- + -- Is_Instance_Node -- + ---------------------- + + function Is_Instance_Node (Decl : Node_Id) return Boolean is + begin + return Nkind (Decl) in N_Generic_Instantiation + or else + Nkind (Original_Node (Decl)) = N_Formal_Package_Declaration; + end Is_Instance_Node; + + -- Start of processing for Is_Global + + begin + if E = Gen_Scope then + return False; + + elsif E = Standard_Standard then + return True; + + elsif Is_Child_Unit (E) + and then (Is_Instance_Node (Parent (N2)) + or else (Nkind (Parent (N2)) = N_Expanded_Name + and then N2 = Selector_Name (Parent (N2)) + and then + Is_Instance_Node (Parent (Parent (N2))))) + then + return True; + + else + Se := Scope (E); + while Se /= Gen_Scope loop + if Se = Standard_Standard then + return True; + else + Se := Scope (Se); + end if; + end loop; + + return False; + end if; + end Is_Global; + + ------------------ + -- Reset_Entity -- + ------------------ + + procedure Reset_Entity (N : Node_Id) is + + procedure Set_Global_Type (N : Node_Id; N2 : Node_Id); + -- If the type of N2 is global to the generic unit, save the type in + -- the generic node. Just as we perform name capture for explicit + -- references within the generic, we must capture the global types + -- of local entities because they may participate in resolution in + -- the instance. + + function Top_Ancestor (E : Entity_Id) return Entity_Id; + -- Find the ultimate ancestor of the current unit. If it is not a + -- generic unit, then the name of the current unit in the prefix of + -- an expanded name must be replaced with its generic homonym to + -- ensure that it will be properly resolved in an instance. + + --------------------- + -- Set_Global_Type -- + --------------------- + + procedure Set_Global_Type (N : Node_Id; N2 : Node_Id) is + Typ : constant Entity_Id := Etype (N2); + + begin + Set_Etype (N, Typ); + + if Entity (N) /= N2 + and then Has_Private_View (Entity (N)) + then + -- If the entity of N is not the associated node, this is a + -- nested generic and it has an associated node as well, whose + -- type is already the full view (see below). Indicate that the + -- original node has a private view. + + Set_Has_Private_View (N); + end if; + + -- If not a private type, nothing else to do + + if not Is_Private_Type (Typ) then + if Is_Array_Type (Typ) + and then Is_Private_Type (Component_Type (Typ)) + then + Set_Has_Private_View (N); + end if; + + -- If it is a derivation of a private type in a context where no + -- full view is needed, nothing to do either. + + elsif No (Full_View (Typ)) and then Typ /= Etype (Typ) then + null; + + -- Otherwise mark the type for flipping and use the full view when + -- available. + + else + Set_Has_Private_View (N); + + if Present (Full_View (Typ)) then + Set_Etype (N2, Full_View (Typ)); + end if; + end if; + end Set_Global_Type; + + ------------------ + -- Top_Ancestor -- + ------------------ + + function Top_Ancestor (E : Entity_Id) return Entity_Id is + Par : Entity_Id; + + begin + Par := E; + while Is_Child_Unit (Par) loop + Par := Scope (Par); + end loop; + + return Par; + end Top_Ancestor; + + -- Start of processing for Reset_Entity + + begin + N2 := Get_Associated_Node (N); + E := Entity (N2); + + if Present (E) then + + -- If the node is an entry call to an entry in an enclosing task, + -- it is rewritten as a selected component. No global entity to + -- preserve in this case, since the expansion will be redone in + -- the instance. + + if not Nkind_In (E, N_Defining_Identifier, + N_Defining_Character_Literal, + N_Defining_Operator_Symbol) + then + Set_Associated_Node (N, Empty); + Set_Etype (N, Empty); + return; + end if; + + -- If the entity is an itype created as a subtype of an access + -- type with a null exclusion restore source entity for proper + -- visibility. The itype will be created anew in the instance. + + if Is_Itype (E) + and then Ekind (E) = E_Access_Subtype + and then Is_Entity_Name (N) + and then Chars (Etype (E)) = Chars (N) + then + E := Etype (E); + Set_Entity (N2, E); + Set_Etype (N2, E); + end if; + + if Is_Global (E) then + + -- If the entity is a package renaming that is the prefix of + -- an expanded name, it has been rewritten as the renamed + -- package, which is necessary semantically but complicates + -- ASIS tree traversal, so we recover the original entity to + -- expose the renaming. Take into account that the context may + -- be a nested generic, that the original node may itself have + -- an associated node that had better be an entity, and that + -- the current node is still a selected component. + + if Ekind (E) = E_Package + and then Nkind (N) = N_Selected_Component + and then Nkind (Parent (N)) = N_Expanded_Name + and then Present (Original_Node (N2)) + and then Is_Entity_Name (Original_Node (N2)) + and then Present (Entity (Original_Node (N2))) + then + if Is_Global (Entity (Original_Node (N2))) then + N2 := Original_Node (N2); + Set_Associated_Node (N, N2); + Set_Global_Type (N, N2); + + else + -- Renaming is local, and will be resolved in instance + + Set_Associated_Node (N, Empty); + Set_Etype (N, Empty); + end if; + + else + Set_Global_Type (N, N2); + end if; + + elsif Nkind (N) = N_Op_Concat + and then Is_Generic_Type (Etype (N2)) + and then (Base_Type (Etype (Right_Opnd (N2))) = Etype (N2) + or else + Base_Type (Etype (Left_Opnd (N2))) = Etype (N2)) + and then Is_Intrinsic_Subprogram (E) + then + null; + + else + -- Entity is local. Mark generic node as unresolved. + -- Note that now it does not have an entity. + + Set_Associated_Node (N, Empty); + Set_Etype (N, Empty); + end if; + + if Nkind (Parent (N)) in N_Generic_Instantiation + and then N = Name (Parent (N)) + then + Save_Global_Defaults (Parent (N), Parent (N2)); + end if; + + elsif Nkind (Parent (N)) = N_Selected_Component + and then Nkind (Parent (N2)) = N_Expanded_Name + then + if Is_Global (Entity (Parent (N2))) then + Change_Selected_Component_To_Expanded_Name (Parent (N)); + Set_Associated_Node (Parent (N), Parent (N2)); + Set_Global_Type (Parent (N), Parent (N2)); + Save_Entity_Descendants (N); + + -- If this is a reference to the current generic entity, replace + -- by the name of the generic homonym of the current package. This + -- is because in an instantiation Par.P.Q will not resolve to the + -- name of the instance, whose enclosing scope is not necessarily + -- Par. We use the generic homonym rather that the name of the + -- generic itself because it may be hidden by a local declaration. + + elsif In_Open_Scopes (Entity (Parent (N2))) + and then not + Is_Generic_Unit (Top_Ancestor (Entity (Prefix (Parent (N2))))) + then + if Ekind (Entity (Parent (N2))) = E_Generic_Package then + Rewrite (Parent (N), + Make_Identifier (Sloc (N), + Chars => + Chars (Generic_Homonym (Entity (Parent (N2)))))); + else + Rewrite (Parent (N), + Make_Identifier (Sloc (N), + Chars => Chars (Selector_Name (Parent (N2))))); + end if; + end if; + + if Nkind (Parent (Parent (N))) in N_Generic_Instantiation + and then Parent (N) = Name (Parent (Parent (N))) + then + Save_Global_Defaults + (Parent (Parent (N)), Parent (Parent ((N2)))); + end if; + + -- A selected component may denote a static constant that has been + -- folded. If the static constant is global to the generic, capture + -- its value. Otherwise the folding will happen in any instantiation. + + elsif Nkind (Parent (N)) = N_Selected_Component + and then Nkind_In (Parent (N2), N_Integer_Literal, N_Real_Literal) + then + if Present (Entity (Original_Node (Parent (N2)))) + and then Is_Global (Entity (Original_Node (Parent (N2)))) + then + Rewrite (Parent (N), New_Copy (Parent (N2))); + Set_Analyzed (Parent (N), False); + + else + null; + end if; + + -- A selected component may be transformed into a parameterless + -- function call. If the called entity is global, rewrite the node + -- appropriately, i.e. as an extended name for the global entity. + + elsif Nkind (Parent (N)) = N_Selected_Component + and then Nkind (Parent (N2)) = N_Function_Call + and then N = Selector_Name (Parent (N)) + then + if No (Parameter_Associations (Parent (N2))) then + if Is_Global (Entity (Name (Parent (N2)))) then + Change_Selected_Component_To_Expanded_Name (Parent (N)); + Set_Associated_Node (Parent (N), Name (Parent (N2))); + Set_Global_Type (Parent (N), Name (Parent (N2))); + Save_Entity_Descendants (N); + + else + Set_Is_Prefixed_Call (Parent (N)); + Set_Associated_Node (N, Empty); + Set_Etype (N, Empty); + end if; + + -- In Ada 2005, X.F may be a call to a primitive operation, + -- rewritten as F (X). This rewriting will be done again in an + -- instance, so keep the original node. Global entities will be + -- captured as for other constructs. Indicate that this must + -- resolve as a call, to prevent accidental overloading in the + -- instance, if both a component and a primitive operation appear + -- as candidates. + + else + Set_Is_Prefixed_Call (Parent (N)); + end if; + + -- Entity is local. Reset in generic unit, so that node is resolved + -- anew at the point of instantiation. + + else + Set_Associated_Node (N, Empty); + Set_Etype (N, Empty); + end if; + end Reset_Entity; + + ----------------------------- + -- Save_Entity_Descendants -- + ----------------------------- + + procedure Save_Entity_Descendants (N : Node_Id) is + begin + case Nkind (N) is + when N_Binary_Op => + Save_Global_Descendant (Union_Id (Left_Opnd (N))); + Save_Global_Descendant (Union_Id (Right_Opnd (N))); + + when N_Unary_Op => + Save_Global_Descendant (Union_Id (Right_Opnd (N))); + + when N_Expanded_Name | N_Selected_Component => + Save_Global_Descendant (Union_Id (Prefix (N))); + Save_Global_Descendant (Union_Id (Selector_Name (N))); + + when N_Identifier | N_Character_Literal | N_Operator_Symbol => + null; + + when others => + raise Program_Error; + end case; + end Save_Entity_Descendants; + + -------------------------- + -- Save_Global_Defaults -- + -------------------------- + + procedure Save_Global_Defaults (N1, N2 : Node_Id) is + Loc : constant Source_Ptr := Sloc (N1); + Assoc2 : constant List_Id := Generic_Associations (N2); + Gen_Id : constant Entity_Id := Get_Generic_Entity (N2); + Assoc1 : List_Id; + Act1 : Node_Id; + Act2 : Node_Id; + Def : Node_Id; + Ndec : Node_Id; + Subp : Entity_Id; + Actual : Entity_Id; + + begin + Assoc1 := Generic_Associations (N1); + + if Present (Assoc1) then + Act1 := First (Assoc1); + else + Act1 := Empty; + Set_Generic_Associations (N1, New_List); + Assoc1 := Generic_Associations (N1); + end if; + + if Present (Assoc2) then + Act2 := First (Assoc2); + else + return; + end if; + + while Present (Act1) and then Present (Act2) loop + Next (Act1); + Next (Act2); + end loop; + + -- Find the associations added for default subprograms + + if Present (Act2) then + while Nkind (Act2) /= N_Generic_Association + or else No (Entity (Selector_Name (Act2))) + or else not Is_Overloadable (Entity (Selector_Name (Act2))) + loop + Next (Act2); + end loop; + + -- Add a similar association if the default is global. The + -- renaming declaration for the actual has been analyzed, and + -- its alias is the program it renames. Link the actual in the + -- original generic tree with the node in the analyzed tree. + + while Present (Act2) loop + Subp := Entity (Selector_Name (Act2)); + Def := Explicit_Generic_Actual_Parameter (Act2); + + -- Following test is defence against rubbish errors + + if No (Alias (Subp)) then + return; + end if; + + -- Retrieve the resolved actual from the renaming declaration + -- created for the instantiated formal. + + Actual := Entity (Name (Parent (Parent (Subp)))); + Set_Entity (Def, Actual); + Set_Etype (Def, Etype (Actual)); + + if Is_Global (Actual) then + Ndec := + Make_Generic_Association (Loc, + Selector_Name => New_Occurrence_Of (Subp, Loc), + Explicit_Generic_Actual_Parameter => + New_Occurrence_Of (Actual, Loc)); + + Set_Associated_Node + (Explicit_Generic_Actual_Parameter (Ndec), Def); + + Append (Ndec, Assoc1); + + -- If there are other defaults, add a dummy association in case + -- there are other defaulted formals with the same name. + + elsif Present (Next (Act2)) then + Ndec := + Make_Generic_Association (Loc, + Selector_Name => New_Occurrence_Of (Subp, Loc), + Explicit_Generic_Actual_Parameter => Empty); + + Append (Ndec, Assoc1); + end if; + + Next (Act2); + end loop; + end if; + + if Nkind (Name (N1)) = N_Identifier + and then Is_Child_Unit (Gen_Id) + and then Is_Global (Gen_Id) + and then Is_Generic_Unit (Scope (Gen_Id)) + and then In_Open_Scopes (Scope (Gen_Id)) + then + -- This is an instantiation of a child unit within a sibling, so + -- that the generic parent is in scope. An eventual instance must + -- occur within the scope of an instance of the parent. Make name + -- in instance into an expanded name, to preserve the identifier + -- of the parent, so it can be resolved subsequently. + + Rewrite (Name (N2), + Make_Expanded_Name (Loc, + Chars => Chars (Gen_Id), + Prefix => New_Occurrence_Of (Scope (Gen_Id), Loc), + Selector_Name => New_Occurrence_Of (Gen_Id, Loc))); + Set_Entity (Name (N2), Gen_Id); + + Rewrite (Name (N1), + Make_Expanded_Name (Loc, + Chars => Chars (Gen_Id), + Prefix => New_Occurrence_Of (Scope (Gen_Id), Loc), + Selector_Name => New_Occurrence_Of (Gen_Id, Loc))); + + Set_Associated_Node (Name (N1), Name (N2)); + Set_Associated_Node (Prefix (Name (N1)), Empty); + Set_Associated_Node + (Selector_Name (Name (N1)), Selector_Name (Name (N2))); + Set_Etype (Name (N1), Etype (Gen_Id)); + end if; + + end Save_Global_Defaults; + + ---------------------------- + -- Save_Global_Descendant -- + ---------------------------- + + procedure Save_Global_Descendant (D : Union_Id) is + N1 : Node_Id; + + begin + if D in Node_Range then + if D = Union_Id (Empty) then + null; + + elsif Nkind (Node_Id (D)) /= N_Compilation_Unit then + Save_References (Node_Id (D)); + end if; + + elsif D in List_Range then + if D = Union_Id (No_List) + or else Is_Empty_List (List_Id (D)) + then + null; + + else + N1 := First (List_Id (D)); + while Present (N1) loop + Save_References (N1); + Next (N1); + end loop; + end if; + + -- Element list or other non-node field, nothing to do + + else + null; + end if; + end Save_Global_Descendant; + + --------------------- + -- Save_References -- + --------------------- + + -- This is the recursive procedure that does the work once the enclosing + -- generic scope has been established. We have to treat specially a + -- number of node rewritings that are required by semantic processing + -- and which change the kind of nodes in the generic copy: typically + -- constant-folding, replacing an operator node by a string literal, or + -- a selected component by an expanded name. In each of those cases, the + -- transformation is propagated to the generic unit. + + procedure Save_References (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + + begin + if N = Empty then + null; + + elsif Nkind_In (N, N_Character_Literal, N_Operator_Symbol) then + if Nkind (N) = Nkind (Get_Associated_Node (N)) then + Reset_Entity (N); + + elsif Nkind (N) = N_Operator_Symbol + and then Nkind (Get_Associated_Node (N)) = N_String_Literal + then + Change_Operator_Symbol_To_String_Literal (N); + end if; + + elsif Nkind (N) in N_Op then + if Nkind (N) = Nkind (Get_Associated_Node (N)) then + if Nkind (N) = N_Op_Concat then + Set_Is_Component_Left_Opnd (N, + Is_Component_Left_Opnd (Get_Associated_Node (N))); + + Set_Is_Component_Right_Opnd (N, + Is_Component_Right_Opnd (Get_Associated_Node (N))); + end if; + + Reset_Entity (N); + + else + -- Node may be transformed into call to a user-defined operator + + N2 := Get_Associated_Node (N); + + if Nkind (N2) = N_Function_Call then + E := Entity (Name (N2)); + + if Present (E) + and then Is_Global (E) + then + Set_Etype (N, Etype (N2)); + else + Set_Associated_Node (N, Empty); + Set_Etype (N, Empty); + end if; + + elsif Nkind_In (N2, N_Integer_Literal, + N_Real_Literal, + N_String_Literal) + then + if Present (Original_Node (N2)) + and then Nkind (Original_Node (N2)) = Nkind (N) + then + + -- Operation was constant-folded. Whenever possible, + -- recover semantic information from unfolded node, + -- for ASIS use. + + Set_Associated_Node (N, Original_Node (N2)); + + if Nkind (N) = N_Op_Concat then + Set_Is_Component_Left_Opnd (N, + Is_Component_Left_Opnd (Get_Associated_Node (N))); + Set_Is_Component_Right_Opnd (N, + Is_Component_Right_Opnd (Get_Associated_Node (N))); + end if; + + Reset_Entity (N); + + else + -- If original node is already modified, propagate + -- constant-folding to template. + + Rewrite (N, New_Copy (N2)); + Set_Analyzed (N, False); + end if; + + elsif Nkind (N2) = N_Identifier + and then Ekind (Entity (N2)) = E_Enumeration_Literal + then + -- Same if call was folded into a literal, but in this case + -- retain the entity to avoid spurious ambiguities if it is + -- overloaded at the point of instantiation or inlining. + + Rewrite (N, New_Copy (N2)); + Set_Analyzed (N, False); + end if; + end if; + + -- Complete operands check if node has not been constant-folded + + if Nkind (N) in N_Op then + Save_Entity_Descendants (N); + end if; + + elsif Nkind (N) = N_Identifier then + if Nkind (N) = Nkind (Get_Associated_Node (N)) then + + -- If this is a discriminant reference, always save it. It is + -- used in the instance to find the corresponding discriminant + -- positionally rather than by name. + + Set_Original_Discriminant + (N, Original_Discriminant (Get_Associated_Node (N))); + Reset_Entity (N); + + else + N2 := Get_Associated_Node (N); + + if Nkind (N2) = N_Function_Call then + E := Entity (Name (N2)); + + -- Name resolves to a call to parameterless function. If + -- original entity is global, mark node as resolved. + + if Present (E) + and then Is_Global (E) + then + Set_Etype (N, Etype (N2)); + else + Set_Associated_Node (N, Empty); + Set_Etype (N, Empty); + end if; + + elsif Nkind_In (N2, N_Integer_Literal, N_Real_Literal) + and then Is_Entity_Name (Original_Node (N2)) + then + -- Name resolves to named number that is constant-folded, + -- We must preserve the original name for ASIS use, and + -- undo the constant-folding, which will be repeated in + -- each instance. + + Set_Associated_Node (N, Original_Node (N2)); + Reset_Entity (N); + + elsif Nkind (N2) = N_String_Literal then + + -- Name resolves to string literal. Perform the same + -- replacement in generic. + + Rewrite (N, New_Copy (N2)); + + elsif Nkind (N2) = N_Explicit_Dereference then + + -- An identifier is rewritten as a dereference if it is the + -- prefix in an implicit dereference (call or attribute). + -- The analysis of an instantiation will expand the node + -- again, so we preserve the original tree but link it to + -- the resolved entity in case it is global. + + if Is_Entity_Name (Prefix (N2)) + and then Present (Entity (Prefix (N2))) + and then Is_Global (Entity (Prefix (N2))) + then + Set_Associated_Node (N, Prefix (N2)); + + elsif Nkind (Prefix (N2)) = N_Function_Call + and then Is_Global (Entity (Name (Prefix (N2)))) + then + Rewrite (N, + Make_Explicit_Dereference (Loc, + Prefix => Make_Function_Call (Loc, + Name => + New_Occurrence_Of (Entity (Name (Prefix (N2))), + Loc)))); + + else + Set_Associated_Node (N, Empty); + Set_Etype (N, Empty); + end if; + + -- The subtype mark of a nominally unconstrained object is + -- rewritten as a subtype indication using the bounds of the + -- expression. Recover the original subtype mark. + + elsif Nkind (N2) = N_Subtype_Indication + and then Is_Entity_Name (Original_Node (N2)) + then + Set_Associated_Node (N, Original_Node (N2)); + Reset_Entity (N); + + else + null; + end if; + end if; + + elsif Nkind (N) in N_Entity then + null; + + else + declare + Qual : Node_Id := Empty; + Typ : Entity_Id := Empty; + Nam : Node_Id; + + use Atree.Unchecked_Access; + -- This code section is part of implementing an untyped tree + -- traversal, so it needs direct access to node fields. + + begin + if Nkind_In (N, N_Aggregate, N_Extension_Aggregate) then + N2 := Get_Associated_Node (N); + + if No (N2) then + Typ := Empty; + else + Typ := Etype (N2); + + -- In an instance within a generic, use the name of the + -- actual and not the original generic parameter. If the + -- actual is global in the current generic it must be + -- preserved for its instantiation. + + if Nkind (Parent (Typ)) = N_Subtype_Declaration + and then + Present (Generic_Parent_Type (Parent (Typ))) + then + Typ := Base_Type (Typ); + Set_Etype (N2, Typ); + end if; + end if; + + if No (N2) + or else No (Typ) + or else not Is_Global (Typ) + then + Set_Associated_Node (N, Empty); + + -- If the aggregate is an actual in a call, it has been + -- resolved in the current context, to some local type. + -- The enclosing call may have been disambiguated by the + -- aggregate, and this disambiguation might fail at + -- instantiation time because the type to which the + -- aggregate did resolve is not preserved. In order to + -- preserve some of this information, we wrap the + -- aggregate in a qualified expression, using the id of + -- its type. For further disambiguation we qualify the + -- type name with its scope (if visible) because both + -- id's will have corresponding entities in an instance. + -- This resolves most of the problems with missing type + -- information on aggregates in instances. + + if Nkind (N2) = Nkind (N) + and then Nkind (Parent (N2)) in N_Subprogram_Call + and then Comes_From_Source (Typ) + then + if Is_Immediately_Visible (Scope (Typ)) then + Nam := Make_Selected_Component (Loc, + Prefix => + Make_Identifier (Loc, Chars (Scope (Typ))), + Selector_Name => + Make_Identifier (Loc, Chars (Typ))); + else + Nam := Make_Identifier (Loc, Chars (Typ)); + end if; + + Qual := + Make_Qualified_Expression (Loc, + Subtype_Mark => Nam, + Expression => Relocate_Node (N)); + end if; + end if; + + Save_Global_Descendant (Field1 (N)); + Save_Global_Descendant (Field2 (N)); + Save_Global_Descendant (Field3 (N)); + Save_Global_Descendant (Field5 (N)); + + if Present (Qual) then + Rewrite (N, Qual); + end if; + + -- All other cases than aggregates + + else + Save_Global_Descendant (Field1 (N)); + Save_Global_Descendant (Field2 (N)); + Save_Global_Descendant (Field3 (N)); + Save_Global_Descendant (Field4 (N)); + Save_Global_Descendant (Field5 (N)); + end if; + end; + end if; + + -- If a node has aspects, references within their expressions must + -- be saved separately, given they are not directly in the tree. + + if Has_Aspects (N) then + declare + Aspect : Node_Id; + + begin + Aspect := First (Aspect_Specifications (N)); + while Present (Aspect) loop + if Present (Expression (Aspect)) then + Save_Global_References (Expression (Aspect)); + end if; + + Next (Aspect); + end loop; + end; + end if; + end Save_References; + + -- Start of processing for Save_Global_References + + begin + Gen_Scope := Current_Scope; + + -- If the generic unit is a child unit, references to entities in the + -- parent are treated as local, because they will be resolved anew in + -- the context of the instance of the parent. + + while Is_Child_Unit (Gen_Scope) + and then Ekind (Scope (Gen_Scope)) = E_Generic_Package + loop + Gen_Scope := Scope (Gen_Scope); + end loop; + + Save_References (N); + end Save_Global_References; + + -------------------------------------- + -- Set_Copied_Sloc_For_Inlined_Body -- + -------------------------------------- + + procedure Set_Copied_Sloc_For_Inlined_Body (N : Node_Id; E : Entity_Id) is + begin + Create_Instantiation_Source (N, E, True, S_Adjustment); + end Set_Copied_Sloc_For_Inlined_Body; + + --------------------- + -- Set_Instance_Of -- + --------------------- + + procedure Set_Instance_Of (A : Entity_Id; B : Entity_Id) is + begin + Generic_Renamings.Table (Generic_Renamings.Last) := (A, B, Assoc_Null); + Generic_Renamings_HTable.Set (Generic_Renamings.Last); + Generic_Renamings.Increment_Last; + end Set_Instance_Of; + + -------------------- + -- Set_Next_Assoc -- + -------------------- + + procedure Set_Next_Assoc (E : Assoc_Ptr; Next : Assoc_Ptr) is + begin + Generic_Renamings.Table (E).Next_In_HTable := Next; + end Set_Next_Assoc; + + ------------------- + -- Start_Generic -- + ------------------- + + procedure Start_Generic is + begin + -- ??? More things could be factored out in this routine. + -- Should probably be done at a later stage. + + Generic_Flags.Append (Inside_A_Generic); + Inside_A_Generic := True; + + Expander_Mode_Save_And_Set (False); + end Start_Generic; + + ---------------------- + -- Set_Instance_Env -- + ---------------------- + + procedure Set_Instance_Env + (Gen_Unit : Entity_Id; + Act_Unit : Entity_Id) + is + Assertion_Status : constant Boolean := Assertions_Enabled; + Save_SPARK_Mode : constant SPARK_Mode_Type := SPARK_Mode; + Save_SPARK_Mode_Pragma : constant Node_Id := SPARK_Mode_Pragma; + + begin + -- Regardless of the current mode, predefined units are analyzed in the + -- most current Ada mode, and earlier version Ada checks do not apply + -- to predefined units. Nothing needs to be done for non-internal units. + -- These are always analyzed in the current mode. + + if Is_Internal_File_Name + (Fname => Unit_File_Name (Get_Source_Unit (Gen_Unit)), + Renamings_Included => True) + then + Set_Opt_Config_Switches (True, Current_Sem_Unit = Main_Unit); + + -- In Ada2012 we may want to enable assertions in an instance of a + -- predefined unit, in which case we need to preserve the current + -- setting for the Assertions_Enabled flag. This will become more + -- critical when pre/postconditions are added to predefined units, + -- as is already the case for some numeric libraries. + + if Ada_Version >= Ada_2012 then + Assertions_Enabled := Assertion_Status; + end if; + + -- SPARK_Mode for an instance is the one applicable at the point of + -- instantiation. + + SPARK_Mode := Save_SPARK_Mode; + SPARK_Mode_Pragma := Save_SPARK_Mode_Pragma; + end if; + + Current_Instantiated_Parent := + (Gen_Id => Gen_Unit, + Act_Id => Act_Unit, + Next_In_HTable => Assoc_Null); + end Set_Instance_Env; + + ----------------- + -- Switch_View -- + ----------------- + + procedure Switch_View (T : Entity_Id) is + BT : constant Entity_Id := Base_Type (T); + Priv_Elmt : Elmt_Id := No_Elmt; + Priv_Sub : Entity_Id; + + begin + -- T may be private but its base type may have been exchanged through + -- some other occurrence, in which case there is nothing to switch + -- besides T itself. Note that a private dependent subtype of a private + -- type might not have been switched even if the base type has been, + -- because of the last branch of Check_Private_View (see comment there). + + if not Is_Private_Type (BT) then + Prepend_Elmt (Full_View (T), Exchanged_Views); + Exchange_Declarations (T); + return; + end if; + + Priv_Elmt := First_Elmt (Private_Dependents (BT)); + + if Present (Full_View (BT)) then + Prepend_Elmt (Full_View (BT), Exchanged_Views); + Exchange_Declarations (BT); + end if; + + while Present (Priv_Elmt) loop + Priv_Sub := (Node (Priv_Elmt)); + + -- We avoid flipping the subtype if the Etype of its full view is + -- private because this would result in a malformed subtype. This + -- occurs when the Etype of the subtype full view is the full view of + -- the base type (and since the base types were just switched, the + -- subtype is pointing to the wrong view). This is currently the case + -- for tagged record types, access types (maybe more?) and needs to + -- be resolved. ??? + + if Present (Full_View (Priv_Sub)) + and then not Is_Private_Type (Etype (Full_View (Priv_Sub))) + then + Prepend_Elmt (Full_View (Priv_Sub), Exchanged_Views); + Exchange_Declarations (Priv_Sub); + end if; + + Next_Elmt (Priv_Elmt); + end loop; + end Switch_View; + + ----------------- + -- True_Parent -- + ----------------- + + function True_Parent (N : Node_Id) return Node_Id is + begin + if Nkind (Parent (N)) = N_Subunit then + return Parent (Corresponding_Stub (Parent (N))); + else + return Parent (N); + end if; + end True_Parent; + + ----------------------------- + -- Valid_Default_Attribute -- + ----------------------------- + + procedure Valid_Default_Attribute (Nam : Entity_Id; Def : Node_Id) is + Attr_Id : constant Attribute_Id := + Get_Attribute_Id (Attribute_Name (Def)); + T : constant Entity_Id := Entity (Prefix (Def)); + Is_Fun : constant Boolean := (Ekind (Nam) = E_Function); + F : Entity_Id; + Num_F : Int; + OK : Boolean; + + begin + if No (T) + or else T = Any_Id + then + return; + end if; + + Num_F := 0; + F := First_Formal (Nam); + while Present (F) loop + Num_F := Num_F + 1; + Next_Formal (F); + end loop; + + case Attr_Id is + when Attribute_Adjacent | Attribute_Ceiling | Attribute_Copy_Sign | + Attribute_Floor | Attribute_Fraction | Attribute_Machine | + Attribute_Model | Attribute_Remainder | Attribute_Rounding | + Attribute_Unbiased_Rounding => + OK := Is_Fun + and then Num_F = 1 + and then Is_Floating_Point_Type (T); + + when Attribute_Image | Attribute_Pred | Attribute_Succ | + Attribute_Value | Attribute_Wide_Image | + Attribute_Wide_Value => + OK := (Is_Fun and then Num_F = 1 and then Is_Scalar_Type (T)); + + when Attribute_Max | Attribute_Min => + OK := (Is_Fun and then Num_F = 2 and then Is_Scalar_Type (T)); + + when Attribute_Input => + OK := (Is_Fun and then Num_F = 1); + + when Attribute_Output | Attribute_Read | Attribute_Write => + OK := (not Is_Fun and then Num_F = 2); + + when others => + OK := False; + end case; + + if not OK then + Error_Msg_N ("attribute reference has wrong profile for subprogram", + Def); + end if; + end Valid_Default_Attribute; + +end Sem_Ch12; |