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diff --git a/gcc-4.4.0/gcc/ada/sem_ch8.adb b/gcc-4.4.0/gcc/ada/sem_ch8.adb deleted file mode 100644 index 3e231f612..000000000 --- a/gcc-4.4.0/gcc/ada/sem_ch8.adb +++ /dev/null @@ -1,7262 +0,0 @@ ------------------------------------------------------------------------------- --- -- --- GNAT COMPILER COMPONENTS -- --- -- --- S E M . C H 8 -- --- -- --- B o d y -- --- -- --- Copyright (C) 1992-2008, 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 Atree; use Atree; -with Debug; use Debug; -with Einfo; use Einfo; -with Elists; use Elists; -with Errout; use Errout; -with Exp_Tss; use Exp_Tss; -with Exp_Util; use Exp_Util; -with Fname; use Fname; -with Freeze; use Freeze; -with Impunit; use Impunit; -with Lib; use Lib; -with Lib.Load; use Lib.Load; -with Lib.Xref; use Lib.Xref; -with Namet; use Namet; -with Namet.Sp; use Namet.Sp; -with Nlists; use Nlists; -with Nmake; use Nmake; -with Opt; use Opt; -with Output; use Output; -with Restrict; use Restrict; -with Rident; use Rident; -with Rtsfind; use Rtsfind; -with Sem; use Sem; -with Sem_Cat; use Sem_Cat; -with Sem_Ch3; use Sem_Ch3; -with Sem_Ch4; use Sem_Ch4; -with Sem_Ch6; use Sem_Ch6; -with Sem_Ch12; use Sem_Ch12; -with Sem_Disp; use Sem_Disp; -with Sem_Dist; use Sem_Dist; -with Sem_Res; use Sem_Res; -with Sem_Util; use Sem_Util; -with Sem_Type; use Sem_Type; -with Stand; use Stand; -with Sinfo; use Sinfo; -with Sinfo.CN; use Sinfo.CN; -with Snames; use Snames; -with Style; use Style; -with Table; -with Tbuild; use Tbuild; -with Uintp; use Uintp; - -package body Sem_Ch8 is - - ------------------------------------ - -- Visibility and Name Resolution -- - ------------------------------------ - - -- This package handles name resolution and the collection of - -- interpretations for overloaded names, prior to overload resolution. - - -- Name resolution is the process that establishes a mapping between source - -- identifiers and the entities they denote at each point in the program. - -- Each entity is represented by a defining occurrence. Each identifier - -- that denotes an entity points to the corresponding defining occurrence. - -- This is the entity of the applied occurrence. Each occurrence holds - -- an index into the names table, where source identifiers are stored. - - -- Each entry in the names table for an identifier or designator uses the - -- Info pointer to hold a link to the currently visible entity that has - -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id - -- in package Sem_Util). The visibility is initialized at the beginning of - -- semantic processing to make entities in package Standard immediately - -- visible. The visibility table is used in a more subtle way when - -- compiling subunits (see below). - - -- Entities that have the same name (i.e. homonyms) are chained. In the - -- case of overloaded entities, this chain holds all the possible meanings - -- of a given identifier. The process of overload resolution uses type - -- information to select from this chain the unique meaning of a given - -- identifier. - - -- Entities are also chained in their scope, through the Next_Entity link. - -- As a consequence, the name space is organized as a sparse matrix, where - -- each row corresponds to a scope, and each column to a source identifier. - -- Open scopes, that is to say scopes currently being compiled, have their - -- corresponding rows of entities in order, innermost scope first. - - -- The scopes of packages that are mentioned in context clauses appear in - -- no particular order, interspersed among open scopes. This is because - -- in the course of analyzing the context of a compilation, a package - -- declaration is first an open scope, and subsequently an element of the - -- context. If subunits or child units are present, a parent unit may - -- appear under various guises at various times in the compilation. - - -- When the compilation of the innermost scope is complete, the entities - -- defined therein are no longer visible. If the scope is not a package - -- declaration, these entities are never visible subsequently, and can be - -- removed from visibility chains. If the scope is a package declaration, - -- its visible declarations may still be accessible. Therefore the entities - -- defined in such a scope are left on the visibility chains, and only - -- their visibility (immediately visibility or potential use-visibility) - -- is affected. - - -- The ordering of homonyms on their chain does not necessarily follow - -- the order of their corresponding scopes on the scope stack. For - -- example, if package P and the enclosing scope both contain entities - -- named E, then when compiling the package body the chain for E will - -- hold the global entity first, and the local one (corresponding to - -- the current inner scope) next. As a result, name resolution routines - -- do not assume any relative ordering of the homonym chains, either - -- for scope nesting or to order of appearance of context clauses. - - -- When compiling a child unit, entities in the parent scope are always - -- immediately visible. When compiling the body of a child unit, private - -- entities in the parent must also be made immediately visible. There - -- are separate routines to make the visible and private declarations - -- visible at various times (see package Sem_Ch7). - - -- +--------+ +-----+ - -- | In use |-------->| EU1 |--------------------------> - -- +--------+ +-----+ - -- | | - -- +--------+ +-----+ +-----+ - -- | Stand. |---------------->| ES1 |--------------->| ES2 |---> - -- +--------+ +-----+ +-----+ - -- | | - -- +---------+ | +-----+ - -- | with'ed |------------------------------>| EW2 |---> - -- +---------+ | +-----+ - -- | | - -- +--------+ +-----+ +-----+ - -- | Scope2 |---------------->| E12 |--------------->| E22 |---> - -- +--------+ +-----+ +-----+ - -- | | - -- +--------+ +-----+ +-----+ - -- | Scope1 |---------------->| E11 |--------------->| E12 |---> - -- +--------+ +-----+ +-----+ - -- ^ | | - -- | | | - -- | +---------+ | | - -- | | with'ed |-----------------------------------------> - -- | +---------+ | | - -- | | | - -- Scope stack | | - -- (innermost first) | | - -- +----------------------------+ - -- Names table => | Id1 | | | | Id2 | - -- +----------------------------+ - - -- Name resolution must deal with several syntactic forms: simple names, - -- qualified names, indexed names, and various forms of calls. - - -- Each identifier points to an entry in the names table. The resolution - -- of a simple name consists in traversing the homonym chain, starting - -- from the names table. If an entry is immediately visible, it is the one - -- designated by the identifier. If only potentially use-visible entities - -- are on the chain, we must verify that they do not hide each other. If - -- the entity we find is overloadable, we collect all other overloadable - -- entities on the chain as long as they are not hidden. - -- - -- To resolve expanded names, we must find the entity at the intersection - -- of the entity chain for the scope (the prefix) and the homonym chain - -- for the selector. In general, homonym chains will be much shorter than - -- entity chains, so it is preferable to start from the names table as - -- well. If the entity found is overloadable, we must collect all other - -- interpretations that are defined in the scope denoted by the prefix. - - -- For records, protected types, and tasks, their local entities are - -- removed from visibility chains on exit from the corresponding scope. - -- From the outside, these entities are always accessed by selected - -- notation, and the entity chain for the record type, protected type, - -- etc. is traversed sequentially in order to find the designated entity. - - -- The discriminants of a type and the operations of a protected type or - -- task are unchained on exit from the first view of the type, (such as - -- a private or incomplete type declaration, or a protected type speci- - -- fication) and re-chained when compiling the second view. - - -- In the case of operators, we do not make operators on derived types - -- explicit. As a result, the notation P."+" may denote either a user- - -- defined function with name "+", or else an implicit declaration of the - -- operator "+" in package P. The resolution of expanded names always - -- tries to resolve an operator name as such an implicitly defined entity, - -- in addition to looking for explicit declarations. - - -- All forms of names that denote entities (simple names, expanded names, - -- character literals in some cases) have a Entity attribute, which - -- identifies the entity denoted by the name. - - --------------------- - -- The Scope Stack -- - --------------------- - - -- The Scope stack keeps track of the scopes currently been compiled. - -- Every entity that contains declarations (including records) is placed - -- on the scope stack while it is being processed, and removed at the end. - -- Whenever a non-package scope is exited, the entities defined therein - -- are removed from the visibility table, so that entities in outer scopes - -- become visible (see previous description). On entry to Sem, the scope - -- stack only contains the package Standard. As usual, subunits complicate - -- this picture ever so slightly. - - -- The Rtsfind mechanism can force a call to Semantics while another - -- compilation is in progress. The unit retrieved by Rtsfind must be - -- compiled in its own context, and has no access to the visibility of - -- the unit currently being compiled. The procedures Save_Scope_Stack and - -- Restore_Scope_Stack make entities in current open scopes invisible - -- before compiling the retrieved unit, and restore the compilation - -- environment afterwards. - - ------------------------ - -- Compiling subunits -- - ------------------------ - - -- Subunits must be compiled in the environment of the corresponding stub, - -- that is to say with the same visibility into the parent (and its - -- context) that is available at the point of the stub declaration, but - -- with the additional visibility provided by the context clause of the - -- subunit itself. As a result, compilation of a subunit forces compilation - -- of the parent (see description in lib-). At the point of the stub - -- declaration, Analyze is called recursively to compile the proper body of - -- the subunit, but without reinitializing the names table, nor the scope - -- stack (i.e. standard is not pushed on the stack). In this fashion the - -- context of the subunit is added to the context of the parent, and the - -- subunit is compiled in the correct environment. Note that in the course - -- of processing the context of a subunit, Standard will appear twice on - -- the scope stack: once for the parent of the subunit, and once for the - -- unit in the context clause being compiled. However, the two sets of - -- entities are not linked by homonym chains, so that the compilation of - -- any context unit happens in a fresh visibility environment. - - ------------------------------- - -- Processing of USE Clauses -- - ------------------------------- - - -- Every defining occurrence has a flag indicating if it is potentially use - -- visible. Resolution of simple names examines this flag. The processing - -- of use clauses consists in setting this flag on all visible entities - -- defined in the corresponding package. On exit from the scope of the use - -- clause, the corresponding flag must be reset. However, a package may - -- appear in several nested use clauses (pathological but legal, alas!) - -- which forces us to use a slightly more involved scheme: - - -- a) The defining occurrence for a package holds a flag -In_Use- to - -- indicate that it is currently in the scope of a use clause. If a - -- redundant use clause is encountered, then the corresponding occurrence - -- of the package name is flagged -Redundant_Use-. - - -- b) On exit from a scope, the use clauses in its declarative part are - -- scanned. The visibility flag is reset in all entities declared in - -- package named in a use clause, as long as the package is not flagged - -- as being in a redundant use clause (in which case the outer use - -- clause is still in effect, and the direct visibility of its entities - -- must be retained). - - -- Note that entities are not removed from their homonym chains on exit - -- from the package specification. A subsequent use clause does not need - -- to rechain the visible entities, but only to establish their direct - -- visibility. - - ----------------------------------- - -- Handling private declarations -- - ----------------------------------- - - -- The principle that each entity has a single defining occurrence clashes - -- with the presence of two separate definitions for private types: the - -- first is the private type declaration, and second is the full type - -- declaration. It is important that all references to the type point to - -- the same defining occurrence, namely the first one. To enforce the two - -- separate views of the entity, the corresponding information is swapped - -- between the two declarations. Outside of the package, the defining - -- occurrence only contains the private declaration information, while in - -- the private part and the body of the package the defining occurrence - -- contains the full declaration. To simplify the swap, the defining - -- occurrence that currently holds the private declaration points to the - -- full declaration. During semantic processing the defining occurrence - -- also points to a list of private dependents, that is to say access types - -- or composite types whose designated types or component types are - -- subtypes or derived types of the private type in question. After the - -- full declaration has been seen, the private dependents are updated to - -- indicate that they have full definitions. - - ------------------------------------ - -- Handling of Undefined Messages -- - ------------------------------------ - - -- In normal mode, only the first use of an undefined identifier generates - -- a message. The table Urefs is used to record error messages that have - -- been issued so that second and subsequent ones do not generate further - -- messages. However, the second reference causes text to be added to the - -- original undefined message noting "(more references follow)". The - -- full error list option (-gnatf) forces messages to be generated for - -- every reference and disconnects the use of this table. - - type Uref_Entry is record - Node : Node_Id; - -- Node for identifier for which original message was posted. The - -- Chars field of this identifier is used to detect later references - -- to the same identifier. - - Err : Error_Msg_Id; - -- Records error message Id of original undefined message. Reset to - -- No_Error_Msg after the second occurrence, where it is used to add - -- text to the original message as described above. - - Nvis : Boolean; - -- Set if the message is not visible rather than undefined - - Loc : Source_Ptr; - -- Records location of error message. Used to make sure that we do - -- not consider a, b : undefined as two separate instances, which - -- would otherwise happen, since the parser converts this sequence - -- to a : undefined; b : undefined. - - end record; - - package Urefs is new Table.Table ( - Table_Component_Type => Uref_Entry, - Table_Index_Type => Nat, - Table_Low_Bound => 1, - Table_Initial => 10, - Table_Increment => 100, - Table_Name => "Urefs"); - - Candidate_Renaming : Entity_Id; - -- Holds a candidate interpretation that appears in a subprogram renaming - -- declaration and does not match the given specification, but matches at - -- least on the first formal. Allows better error message when given - -- specification omits defaulted parameters, a common error. - - ----------------------- - -- Local Subprograms -- - ----------------------- - - procedure Analyze_Generic_Renaming - (N : Node_Id; - K : Entity_Kind); - -- Common processing for all three kinds of generic renaming declarations. - -- Enter new name and indicate that it renames the generic unit. - - procedure Analyze_Renamed_Character - (N : Node_Id; - New_S : Entity_Id; - Is_Body : Boolean); - -- Renamed entity is given by a character literal, which must belong - -- to the return type of the new entity. Is_Body indicates whether the - -- declaration is a renaming_as_body. If the original declaration has - -- already been frozen (because of an intervening body, e.g.) the body of - -- the function must be built now. The same applies to the following - -- various renaming procedures. - - procedure Analyze_Renamed_Dereference - (N : Node_Id; - New_S : Entity_Id; - Is_Body : Boolean); - -- Renamed entity is given by an explicit dereference. Prefix must be a - -- conformant access_to_subprogram type. - - procedure Analyze_Renamed_Entry - (N : Node_Id; - New_S : Entity_Id; - Is_Body : Boolean); - -- If the renamed entity in a subprogram renaming is an entry or protected - -- subprogram, build a body for the new entity whose only statement is a - -- call to the renamed entity. - - procedure Analyze_Renamed_Family_Member - (N : Node_Id; - New_S : Entity_Id; - Is_Body : Boolean); - -- Used when the renamed entity is an indexed component. The prefix must - -- denote an entry family. - - procedure Analyze_Renamed_Primitive_Operation - (N : Node_Id; - New_S : Entity_Id; - Is_Body : Boolean); - -- If the renamed entity in a subprogram renaming is a primitive operation - -- or a class-wide operation in prefix form, save the target object, which - -- must be added to the list of actuals in any subsequent call. - - function Applicable_Use (Pack_Name : Node_Id) return Boolean; - -- Common code to Use_One_Package and Set_Use, to determine whether - -- use clause must be processed. Pack_Name is an entity name that - -- references the package in question. - - procedure Attribute_Renaming (N : Node_Id); - -- Analyze renaming of attribute as function. The renaming declaration N - -- is rewritten as a function body that returns the attribute reference - -- applied to the formals of the function. - - procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id); - -- A renaming_as_body may occur after the entity of the original decla- - -- ration has been frozen. In that case, the body of the new entity must - -- be built now, because the usual mechanism of building the renamed - -- body at the point of freezing will not work. Subp is the subprogram - -- for which N provides the Renaming_As_Body. - - procedure Check_In_Previous_With_Clause - (N : Node_Id; - Nam : Node_Id); - -- N is a use_package clause and Nam the package name, or N is a use_type - -- clause and Nam is the prefix of the type name. In either case, verify - -- that the package is visible at that point in the context: either it - -- appears in a previous with_clause, or because it is a fully qualified - -- name and the root ancestor appears in a previous with_clause. - - procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id); - -- Verify that the entity in a renaming declaration that is a library unit - -- is itself a library unit and not a nested unit or subunit. Also check - -- that if the renaming is a child unit of a generic parent, then the - -- renamed unit must also be a child unit of that parent. Finally, verify - -- that a renamed generic unit is not an implicit child declared within - -- an instance of the parent. - - procedure Chain_Use_Clause (N : Node_Id); - -- Chain use clause onto list of uses clauses headed by First_Use_Clause in - -- the proper scope table entry. This is usually the current scope, but it - -- will be an inner scope when installing the use clauses of the private - -- declarations of a parent unit prior to compiling the private part of a - -- child unit. This chain is traversed when installing/removing use clauses - -- when compiling a subunit or instantiating a generic body on the fly, - -- when it is necessary to save and restore full environments. - - function Has_Implicit_Character_Literal (N : Node_Id) return Boolean; - -- Find a type derived from Character or Wide_Character in the prefix of N. - -- Used to resolved qualified names whose selector is a character literal. - - function Has_Private_With (E : Entity_Id) return Boolean; - -- Ada 2005 (AI-262): Determines if the current compilation unit has a - -- private with on E. - - procedure Find_Expanded_Name (N : Node_Id); - -- Selected component is known to be expanded name. Verify legality - -- of selector given the scope denoted by prefix. - - function Find_Renamed_Entity - (N : Node_Id; - Nam : Node_Id; - New_S : Entity_Id; - Is_Actual : Boolean := False) return Entity_Id; - -- Find the renamed entity that corresponds to the given parameter profile - -- in a subprogram renaming declaration. The renamed entity may be an - -- operator, a subprogram, an entry, or a protected operation. Is_Actual - -- indicates that the renaming is the one generated for an actual subpro- - -- gram in an instance, for which special visibility checks apply. - - function Has_Implicit_Operator (N : Node_Id) return Boolean; - -- N is an expanded name whose selector is an operator name (e.g. P."+"). - -- declarative part contains an implicit declaration of an operator if it - -- has a declaration of a type to which one of the predefined operators - -- apply. The existence of this routine is an implementation artifact. A - -- more straightforward but more space-consuming choice would be to make - -- all inherited operators explicit in the symbol table. - - procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id); - -- A subprogram defined by a renaming declaration inherits the parameter - -- profile of the renamed entity. The subtypes given in the subprogram - -- specification are discarded and replaced with those of the renamed - -- subprogram, which are then used to recheck the default values. - - function Is_Appropriate_For_Record (T : Entity_Id) return Boolean; - -- Prefix is appropriate for record if it is of a record type, or an access - -- to such. - - function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean; - -- True if it is of a task type, a protected type, or else an access to one - -- of these types. - - procedure Note_Redundant_Use (Clause : Node_Id); - -- Mark the name in a use clause as redundant if the corresponding entity - -- is already use-visible. Emit a warning if the use clause comes from - -- source and the proper warnings are enabled. - - procedure Premature_Usage (N : Node_Id); - -- Diagnose usage of an entity before it is visible - - procedure Use_One_Package (P : Entity_Id; N : Node_Id); - -- Make visible entities declared in package P potentially use-visible - -- in the current context. Also used in the analysis of subunits, when - -- re-installing use clauses of parent units. N is the use_clause that - -- names P (and possibly other packages). - - procedure Use_One_Type (Id : Node_Id); - -- Id is the subtype mark from a use type clause. This procedure makes - -- the primitive operators of the type potentially use-visible. - - procedure Write_Info; - -- Write debugging information on entities declared in current scope - - procedure Write_Scopes; - pragma Warnings (Off, Write_Scopes); - -- Debugging information: dump all entities on scope stack - - -------------------------------- - -- Analyze_Exception_Renaming -- - -------------------------------- - - -- The language only allows a single identifier, but the tree holds an - -- identifier list. The parser has already issued an error message if - -- there is more than one element in the list. - - procedure Analyze_Exception_Renaming (N : Node_Id) is - Id : constant Node_Id := Defining_Identifier (N); - Nam : constant Node_Id := Name (N); - - begin - Enter_Name (Id); - Analyze (Nam); - - Set_Ekind (Id, E_Exception); - Set_Exception_Code (Id, Uint_0); - Set_Etype (Id, Standard_Exception_Type); - Set_Is_Pure (Id, Is_Pure (Current_Scope)); - - if not Is_Entity_Name (Nam) or else - Ekind (Entity (Nam)) /= E_Exception - then - Error_Msg_N ("invalid exception name in renaming", Nam); - else - if Present (Renamed_Object (Entity (Nam))) then - Set_Renamed_Object (Id, Renamed_Object (Entity (Nam))); - else - Set_Renamed_Object (Id, Entity (Nam)); - end if; - end if; - end Analyze_Exception_Renaming; - - --------------------------- - -- Analyze_Expanded_Name -- - --------------------------- - - procedure Analyze_Expanded_Name (N : Node_Id) is - begin - -- If the entity pointer is already set, this is an internal node, or a - -- node that is analyzed more than once, after a tree modification. In - -- such a case there is no resolution to perform, just set the type. For - -- completeness, analyze prefix as well. - - if Present (Entity (N)) then - if Is_Type (Entity (N)) then - Set_Etype (N, Entity (N)); - else - Set_Etype (N, Etype (Entity (N))); - end if; - - Analyze (Prefix (N)); - return; - else - Find_Expanded_Name (N); - end if; - end Analyze_Expanded_Name; - - --------------------------------------- - -- Analyze_Generic_Function_Renaming -- - --------------------------------------- - - procedure Analyze_Generic_Function_Renaming (N : Node_Id) is - begin - Analyze_Generic_Renaming (N, E_Generic_Function); - end Analyze_Generic_Function_Renaming; - - -------------------------------------- - -- Analyze_Generic_Package_Renaming -- - -------------------------------------- - - procedure Analyze_Generic_Package_Renaming (N : Node_Id) is - begin - -- Apply the Text_IO Kludge here, since we may be renaming one of the - -- subpackages of Text_IO, then join common routine. - - Text_IO_Kludge (Name (N)); - - Analyze_Generic_Renaming (N, E_Generic_Package); - end Analyze_Generic_Package_Renaming; - - ---------------------------------------- - -- Analyze_Generic_Procedure_Renaming -- - ---------------------------------------- - - procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is - begin - Analyze_Generic_Renaming (N, E_Generic_Procedure); - end Analyze_Generic_Procedure_Renaming; - - ------------------------------ - -- Analyze_Generic_Renaming -- - ------------------------------ - - procedure Analyze_Generic_Renaming - (N : Node_Id; - K : Entity_Kind) - is - New_P : constant Entity_Id := Defining_Entity (N); - Old_P : Entity_Id; - Inst : Boolean := False; -- prevent junk warning - - begin - if Name (N) = Error then - return; - end if; - - Generate_Definition (New_P); - - if Current_Scope /= Standard_Standard then - Set_Is_Pure (New_P, Is_Pure (Current_Scope)); - end if; - - if Nkind (Name (N)) = N_Selected_Component then - Check_Generic_Child_Unit (Name (N), Inst); - else - Analyze (Name (N)); - end if; - - if not Is_Entity_Name (Name (N)) then - Error_Msg_N ("expect entity name in renaming declaration", Name (N)); - Old_P := Any_Id; - else - Old_P := Entity (Name (N)); - end if; - - Enter_Name (New_P); - Set_Ekind (New_P, K); - - if Etype (Old_P) = Any_Type then - null; - - elsif Ekind (Old_P) /= K then - Error_Msg_N ("invalid generic unit name", Name (N)); - - else - if Present (Renamed_Object (Old_P)) then - Set_Renamed_Object (New_P, Renamed_Object (Old_P)); - else - Set_Renamed_Object (New_P, Old_P); - end if; - - Set_Is_Pure (New_P, Is_Pure (Old_P)); - Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P)); - - Set_Etype (New_P, Etype (Old_P)); - Set_Has_Completion (New_P); - - if In_Open_Scopes (Old_P) then - Error_Msg_N ("within its scope, generic denotes its instance", N); - end if; - - Check_Library_Unit_Renaming (N, Old_P); - end if; - end Analyze_Generic_Renaming; - - ----------------------------- - -- Analyze_Object_Renaming -- - ----------------------------- - - procedure Analyze_Object_Renaming (N : Node_Id) is - Id : constant Entity_Id := Defining_Identifier (N); - Dec : Node_Id; - Nam : constant Node_Id := Name (N); - T : Entity_Id; - T2 : Entity_Id; - - function In_Generic_Scope (E : Entity_Id) return Boolean; - -- Determine whether entity E is inside a generic cope - - ---------------------- - -- In_Generic_Scope -- - ---------------------- - - function In_Generic_Scope (E : Entity_Id) return Boolean is - S : Entity_Id; - - begin - S := Scope (E); - while Present (S) and then S /= Standard_Standard loop - if Is_Generic_Unit (S) then - return True; - end if; - - S := Scope (S); - end loop; - - return False; - end In_Generic_Scope; - - -- Start of processing for Analyze_Object_Renaming - - begin - if Nam = Error then - return; - end if; - - Set_Is_Pure (Id, Is_Pure (Current_Scope)); - Enter_Name (Id); - - -- The renaming of a component that depends on a discriminant requires - -- an actual subtype, because in subsequent use of the object Gigi will - -- be unable to locate the actual bounds. This explicit step is required - -- when the renaming is generated in removing side effects of an - -- already-analyzed expression. - - if Nkind (Nam) = N_Selected_Component - and then Analyzed (Nam) - then - T := Etype (Nam); - Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam); - - if Present (Dec) then - Insert_Action (N, Dec); - T := Defining_Identifier (Dec); - Set_Etype (Nam, T); - end if; - - -- Complete analysis of the subtype mark in any case, for ASIS use - - if Present (Subtype_Mark (N)) then - Find_Type (Subtype_Mark (N)); - end if; - - elsif Present (Subtype_Mark (N)) then - Find_Type (Subtype_Mark (N)); - T := Entity (Subtype_Mark (N)); - Analyze (Nam); - - if Nkind (Nam) = N_Type_Conversion - and then not Is_Tagged_Type (T) - then - Error_Msg_N - ("renaming of conversion only allowed for tagged types", Nam); - end if; - - Resolve (Nam, T); - - -- Check that a class-wide object is not being renamed as an object - -- of a specific type. The test for access types is needed to exclude - -- cases where the renamed object is a dynamically tagged access - -- result, such as occurs in certain expansions. - - if (Is_Class_Wide_Type (Etype (Nam)) - or else (Is_Dynamically_Tagged (Nam) - and then not Is_Access_Type (T))) - and then not Is_Class_Wide_Type (T) - then - Error_Msg_N ("dynamically tagged expression not allowed!", Nam); - end if; - - -- Ada 2005 (AI-230/AI-254): Access renaming - - else pragma Assert (Present (Access_Definition (N))); - T := Access_Definition - (Related_Nod => N, - N => Access_Definition (N)); - - Analyze_And_Resolve (Nam, T); - - -- Ada 2005 (AI-231): "In the case where the type is defined by an - -- access_definition, the renamed entity shall be of an access-to- - -- constant type if and only if the access_definition defines an - -- access-to-constant type" ARM 8.5.1(4) - - if Constant_Present (Access_Definition (N)) - and then not Is_Access_Constant (Etype (Nam)) - then - Error_Msg_N ("(Ada 2005): the renamed object is not " - & "access-to-constant (RM 8.5.1(6))", N); - end if; - end if; - - -- Special processing for renaming function return object - - if Nkind (Nam) = N_Function_Call - and then Comes_From_Source (Nam) - then - case Ada_Version is - - -- Usage is illegal in Ada 83 - - when Ada_83 => - Error_Msg_N - ("(Ada 83) cannot rename function return object", Nam); - - -- In Ada 95, warn for odd case of renaming parameterless function - -- call if this is not a limited type (where this is useful) - - when others => - if Warn_On_Object_Renames_Function - and then No (Parameter_Associations (Nam)) - and then not Is_Limited_Type (Etype (Nam)) - then - Error_Msg_N - ("?renaming function result object is suspicious", - Nam); - Error_Msg_NE - ("\?function & will be called only once", - Nam, Entity (Name (Nam))); - Error_Msg_N - ("\?suggest using an initialized constant object instead", - Nam); - end if; - end case; - end if; - - -- An object renaming requires an exact match of the type. Class-wide - -- matching is not allowed. - - if Is_Class_Wide_Type (T) - and then Base_Type (Etype (Nam)) /= Base_Type (T) - then - Wrong_Type (Nam, T); - end if; - - T2 := Etype (Nam); - - -- (Ada 2005: AI-326): Handle wrong use of incomplete type - - if Nkind (Nam) = N_Explicit_Dereference - and then Ekind (Etype (T2)) = E_Incomplete_Type - then - Error_Msg_NE ("invalid use of incomplete type&", Id, T2); - return; - elsif Ekind (Etype (T)) = E_Incomplete_Type then - Error_Msg_NE ("invalid use of incomplete type&", Id, T); - return; - end if; - - -- Ada 2005 (AI-327) - - if Ada_Version >= Ada_05 - and then Nkind (Nam) = N_Attribute_Reference - and then Attribute_Name (Nam) = Name_Priority - then - null; - - elsif Ada_Version >= Ada_05 - and then Nkind (Nam) in N_Has_Entity - then - declare - Nam_Decl : Node_Id; - Nam_Ent : Entity_Id; - - begin - if Nkind (Nam) = N_Attribute_Reference then - Nam_Ent := Entity (Prefix (Nam)); - else - Nam_Ent := Entity (Nam); - end if; - - Nam_Decl := Parent (Nam_Ent); - - if Has_Null_Exclusion (N) - and then not Has_Null_Exclusion (Nam_Decl) - then - -- Ada 2005 (AI-423): If the object name denotes a generic - -- formal object of a generic unit G, and the object renaming - -- declaration 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. - - if Is_Formal_Object (Nam_Ent) - and then In_Generic_Scope (Id) - then - Error_Msg_N - ("renamed formal does not exclude `NULL` " - & "(RM 8.5.1(4.6/2))", N); - - -- Ada 2005 (AI-423): Otherwise, the subtype of the object name - -- shall exclude null. - - elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then - Error_Msg_N - ("renamed object does not exclude `NULL` " - & "(RM 8.5.1(4.6/2))", N); - - elsif Can_Never_Be_Null (Etype (Nam_Ent)) then - Error_Msg_NE - ("`NOT NULL` not allowed (type of& already excludes null)", - N, Nam_Ent); - - end if; - - elsif Has_Null_Exclusion (N) - and then No (Access_Definition (N)) - and then Can_Never_Be_Null (T) - then - Error_Msg_NE - ("`NOT NULL` not allowed (& already excludes null)", N, T); - end if; - end; - end if; - - Set_Ekind (Id, E_Variable); - Init_Size_Align (Id); - - if T = Any_Type or else Etype (Nam) = Any_Type then - return; - - -- Verify that the renamed entity is an object or a function call. It - -- may have been rewritten in several ways. - - elsif Is_Object_Reference (Nam) then - if Comes_From_Source (N) - and then Is_Dependent_Component_Of_Mutable_Object (Nam) - then - Error_Msg_N - ("illegal renaming of discriminant-dependent component", Nam); - else - null; - end if; - - -- A static function call may have been folded into a literal - - elsif Nkind (Original_Node (Nam)) = N_Function_Call - - -- When expansion is disabled, attribute reference is not - -- rewritten as function call. Otherwise it may be rewritten - -- as a conversion, so check original node. - - or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference - and then Is_Function_Attribute_Name - (Attribute_Name (Original_Node (Nam)))) - - -- Weird but legal, equivalent to renaming a function call. - -- Illegal if the literal is the result of constant-folding an - -- attribute reference that is not a function. - - or else (Is_Entity_Name (Nam) - and then Ekind (Entity (Nam)) = E_Enumeration_Literal - and then - Nkind (Original_Node (Nam)) /= N_Attribute_Reference) - - or else (Nkind (Nam) = N_Type_Conversion - and then Is_Tagged_Type (Entity (Subtype_Mark (Nam)))) - then - null; - - elsif Nkind (Nam) = N_Type_Conversion then - Error_Msg_N - ("renaming of conversion only allowed for tagged types", Nam); - - -- Ada 2005 (AI-327) - - elsif Ada_Version >= Ada_05 - and then Nkind (Nam) = N_Attribute_Reference - and then Attribute_Name (Nam) = Name_Priority - then - null; - - -- Allow internally generated x'Reference expression - - elsif Nkind (Nam) = N_Reference then - null; - - else - Error_Msg_N ("expect object name in renaming", Nam); - end if; - - Set_Etype (Id, T2); - - if not Is_Variable (Nam) then - Set_Ekind (Id, E_Constant); - Set_Never_Set_In_Source (Id, True); - Set_Is_True_Constant (Id, True); - end if; - - Set_Renamed_Object (Id, Nam); - end Analyze_Object_Renaming; - - ------------------------------ - -- Analyze_Package_Renaming -- - ------------------------------ - - procedure Analyze_Package_Renaming (N : Node_Id) is - New_P : constant Entity_Id := Defining_Entity (N); - Old_P : Entity_Id; - Spec : Node_Id; - - begin - if Name (N) = Error then - return; - end if; - - -- Apply Text_IO kludge here, since we may be renaming one of the - -- children of Text_IO. - - Text_IO_Kludge (Name (N)); - - if Current_Scope /= Standard_Standard then - Set_Is_Pure (New_P, Is_Pure (Current_Scope)); - end if; - - Enter_Name (New_P); - Analyze (Name (N)); - - if Is_Entity_Name (Name (N)) then - Old_P := Entity (Name (N)); - else - Old_P := Any_Id; - end if; - - if Etype (Old_P) = Any_Type then - Error_Msg_N - ("expect package name in renaming", Name (N)); - - elsif Ekind (Old_P) /= E_Package - and then not (Ekind (Old_P) = E_Generic_Package - and then In_Open_Scopes (Old_P)) - then - if Ekind (Old_P) = E_Generic_Package then - Error_Msg_N - ("generic package cannot be renamed as a package", Name (N)); - else - Error_Msg_Sloc := Sloc (Old_P); - Error_Msg_NE - ("expect package name in renaming, found& declared#", - Name (N), Old_P); - end if; - - -- Set basic attributes to minimize cascaded errors - - Set_Ekind (New_P, E_Package); - Set_Etype (New_P, Standard_Void_Type); - - -- Here for OK package renaming - - else - -- Entities in the old package are accessible through the renaming - -- entity. The simplest implementation is to have both packages share - -- the entity list. - - Set_Ekind (New_P, E_Package); - Set_Etype (New_P, Standard_Void_Type); - - if Present (Renamed_Object (Old_P)) then - Set_Renamed_Object (New_P, Renamed_Object (Old_P)); - else - Set_Renamed_Object (New_P, Old_P); - end if; - - Set_Has_Completion (New_P); - - Set_First_Entity (New_P, First_Entity (Old_P)); - Set_Last_Entity (New_P, Last_Entity (Old_P)); - Set_First_Private_Entity (New_P, First_Private_Entity (Old_P)); - Check_Library_Unit_Renaming (N, Old_P); - Generate_Reference (Old_P, Name (N)); - - -- If the renaming is in the visible part of a package, then we set - -- Renamed_In_Spec for the renamed package, to prevent giving - -- warnings about no entities referenced. Such a warning would be - -- overenthusiastic, since clients can see entities in the renamed - -- package via the visible package renaming. - - declare - Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit); - begin - if Ekind (Ent) = E_Package - and then not In_Private_Part (Ent) - and then In_Extended_Main_Source_Unit (N) - and then Ekind (Old_P) = E_Package - then - Set_Renamed_In_Spec (Old_P); - end if; - end; - - -- If this is the renaming declaration of a package instantiation - -- within itself, it is the declaration that ends the list of actuals - -- for the instantiation. At this point, the subtypes that rename - -- the actuals are flagged as generic, to avoid spurious ambiguities - -- if the actuals for two distinct formals happen to coincide. If - -- the actual is a private type, the subtype has a private completion - -- that is flagged in the same fashion. - - -- Resolution is identical to what is was in the original generic. - -- On exit from the generic instance, these are turned into regular - -- subtypes again, so they are compatible with types in their class. - - if not Is_Generic_Instance (Old_P) then - return; - else - Spec := Specification (Unit_Declaration_Node (Old_P)); - end if; - - if Nkind (Spec) = N_Package_Specification - and then Present (Generic_Parent (Spec)) - and then Old_P = Current_Scope - and then Chars (New_P) = Chars (Generic_Parent (Spec)) - then - declare - E : Entity_Id; - - begin - E := First_Entity (Old_P); - while Present (E) - and then E /= New_P - loop - if Is_Type (E) - and then Nkind (Parent (E)) = N_Subtype_Declaration - then - Set_Is_Generic_Actual_Type (E); - - if Is_Private_Type (E) - and then Present (Full_View (E)) - then - Set_Is_Generic_Actual_Type (Full_View (E)); - end if; - end if; - - Next_Entity (E); - end loop; - end; - end if; - end if; - end Analyze_Package_Renaming; - - ------------------------------- - -- Analyze_Renamed_Character -- - ------------------------------- - - procedure Analyze_Renamed_Character - (N : Node_Id; - New_S : Entity_Id; - Is_Body : Boolean) - is - C : constant Node_Id := Name (N); - - begin - if Ekind (New_S) = E_Function then - Resolve (C, Etype (New_S)); - - if Is_Body then - Check_Frozen_Renaming (N, New_S); - end if; - - else - Error_Msg_N ("character literal can only be renamed as function", N); - end if; - end Analyze_Renamed_Character; - - --------------------------------- - -- Analyze_Renamed_Dereference -- - --------------------------------- - - procedure Analyze_Renamed_Dereference - (N : Node_Id; - New_S : Entity_Id; - Is_Body : Boolean) - is - Nam : constant Node_Id := Name (N); - P : constant Node_Id := Prefix (Nam); - Typ : Entity_Id; - Ind : Interp_Index; - It : Interp; - - begin - if not Is_Overloaded (P) then - if Ekind (Etype (Nam)) /= E_Subprogram_Type - or else not Type_Conformant (Etype (Nam), New_S) then - Error_Msg_N ("designated type does not match specification", P); - else - Resolve (P); - end if; - - return; - - else - Typ := Any_Type; - Get_First_Interp (Nam, Ind, It); - - while Present (It.Nam) loop - - if Ekind (It.Nam) = E_Subprogram_Type - and then Type_Conformant (It.Nam, New_S) then - - if Typ /= Any_Id then - Error_Msg_N ("ambiguous renaming", P); - return; - else - Typ := It.Nam; - end if; - end if; - - Get_Next_Interp (Ind, It); - end loop; - - if Typ = Any_Type then - Error_Msg_N ("designated type does not match specification", P); - else - Resolve (N, Typ); - - if Is_Body then - Check_Frozen_Renaming (N, New_S); - end if; - end if; - end if; - end Analyze_Renamed_Dereference; - - --------------------------- - -- Analyze_Renamed_Entry -- - --------------------------- - - procedure Analyze_Renamed_Entry - (N : Node_Id; - New_S : Entity_Id; - Is_Body : Boolean) - is - Nam : constant Node_Id := Name (N); - Sel : constant Node_Id := Selector_Name (Nam); - Old_S : Entity_Id; - - begin - if Entity (Sel) = Any_Id then - - -- Selector is undefined on prefix. Error emitted already - - Set_Has_Completion (New_S); - return; - end if; - - -- Otherwise find renamed entity and build body of New_S as a call to it - - Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S); - - if Old_S = Any_Id then - Error_Msg_N (" no subprogram or entry matches specification", N); - else - if Is_Body then - Check_Subtype_Conformant (New_S, Old_S, N); - Generate_Reference (New_S, Defining_Entity (N), 'b'); - Style.Check_Identifier (Defining_Entity (N), New_S); - - else - -- Only mode conformance required for a renaming_as_declaration - - Check_Mode_Conformant (New_S, Old_S, N); - end if; - - Inherit_Renamed_Profile (New_S, Old_S); - - -- The prefix can be an arbitrary expression that yields a task - -- type, so it must be resolved. - - Resolve (Prefix (Nam), Scope (Old_S)); - end if; - - Set_Convention (New_S, Convention (Old_S)); - Set_Has_Completion (New_S, Inside_A_Generic); - - if Is_Body then - Check_Frozen_Renaming (N, New_S); - end if; - end Analyze_Renamed_Entry; - - ----------------------------------- - -- Analyze_Renamed_Family_Member -- - ----------------------------------- - - procedure Analyze_Renamed_Family_Member - (N : Node_Id; - New_S : Entity_Id; - Is_Body : Boolean) - is - Nam : constant Node_Id := Name (N); - P : constant Node_Id := Prefix (Nam); - Old_S : Entity_Id; - - begin - if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family) - or else (Nkind (P) = N_Selected_Component - and then - Ekind (Entity (Selector_Name (P))) = E_Entry_Family) - then - if Is_Entity_Name (P) then - Old_S := Entity (P); - else - Old_S := Entity (Selector_Name (P)); - end if; - - if not Entity_Matches_Spec (Old_S, New_S) then - Error_Msg_N ("entry family does not match specification", N); - - elsif Is_Body then - Check_Subtype_Conformant (New_S, Old_S, N); - Generate_Reference (New_S, Defining_Entity (N), 'b'); - Style.Check_Identifier (Defining_Entity (N), New_S); - end if; - - else - Error_Msg_N ("no entry family matches specification", N); - end if; - - Set_Has_Completion (New_S, Inside_A_Generic); - - if Is_Body then - Check_Frozen_Renaming (N, New_S); - end if; - end Analyze_Renamed_Family_Member; - - ----------------------------------------- - -- Analyze_Renamed_Primitive_Operation -- - ----------------------------------------- - - procedure Analyze_Renamed_Primitive_Operation - (N : Node_Id; - New_S : Entity_Id; - Is_Body : Boolean) - is - Old_S : Entity_Id; - - function Conforms - (Subp : Entity_Id; - Ctyp : Conformance_Type) return Boolean; - -- Verify that the signatures of the renamed entity and the new entity - -- match. The first formal of the renamed entity is skipped because it - -- is the target object in any subsequent call. - - function Conforms - (Subp : Entity_Id; - Ctyp : Conformance_Type) return Boolean - is - Old_F : Entity_Id; - New_F : Entity_Id; - - begin - if Ekind (Subp) /= Ekind (New_S) then - return False; - end if; - - Old_F := Next_Formal (First_Formal (Subp)); - New_F := First_Formal (New_S); - while Present (Old_F) and then Present (New_F) loop - if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then - return False; - end if; - - if Ctyp >= Mode_Conformant - and then Ekind (Old_F) /= Ekind (New_F) - then - return False; - end if; - - Next_Formal (New_F); - Next_Formal (Old_F); - end loop; - - return True; - end Conforms; - - begin - if not Is_Overloaded (Selector_Name (Name (N))) then - Old_S := Entity (Selector_Name (Name (N))); - - if not Conforms (Old_S, Type_Conformant) then - Old_S := Any_Id; - end if; - - else - -- Find the operation that matches the given signature - - declare - It : Interp; - Ind : Interp_Index; - - begin - Old_S := Any_Id; - Get_First_Interp (Selector_Name (Name (N)), Ind, It); - - while Present (It.Nam) loop - if Conforms (It.Nam, Type_Conformant) then - Old_S := It.Nam; - end if; - - Get_Next_Interp (Ind, It); - end loop; - end; - end if; - - if Old_S = Any_Id then - Error_Msg_N (" no subprogram or entry matches specification", N); - - else - if Is_Body then - if not Conforms (Old_S, Subtype_Conformant) then - Error_Msg_N ("subtype conformance error in renaming", N); - end if; - - Generate_Reference (New_S, Defining_Entity (N), 'b'); - Style.Check_Identifier (Defining_Entity (N), New_S); - - else - -- Only mode conformance required for a renaming_as_declaration - - if not Conforms (Old_S, Mode_Conformant) then - Error_Msg_N ("mode conformance error in renaming", N); - end if; - end if; - - -- Inherit_Renamed_Profile (New_S, Old_S); - - -- The prefix can be an arbitrary expression that yields an - -- object, so it must be resolved. - - Resolve (Prefix (Name (N))); - end if; - end Analyze_Renamed_Primitive_Operation; - - --------------------------------- - -- Analyze_Subprogram_Renaming -- - --------------------------------- - - procedure Analyze_Subprogram_Renaming (N : Node_Id) is - Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N); - Is_Actual : constant Boolean := Present (Formal_Spec); - Inst_Node : Node_Id := Empty; - Nam : constant Node_Id := Name (N); - New_S : Entity_Id; - Old_S : Entity_Id := Empty; - Rename_Spec : Entity_Id; - Save_AV : constant Ada_Version_Type := Ada_Version; - Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit; - Spec : constant Node_Id := Specification (N); - - procedure Check_Null_Exclusion - (Ren : Entity_Id; - Sub : Entity_Id); - -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the - -- following AI rules: - -- - -- If Ren is a renaming of a formal subprogram and one of its - -- parameters has a null exclusion, then the corresponding formal - -- in Sub must also have one. Otherwise the subtype of the Sub's - -- formal parameter must exclude null. - -- - -- If Ren is a renaming of a formal function and its return - -- profile has a null exclusion, then Sub's return profile must - -- have one. Otherwise the subtype of Sub's return profile must - -- exclude null. - - function Original_Subprogram (Subp : Entity_Id) return Entity_Id; - -- Find renamed entity when the declaration is a renaming_as_body and - -- the renamed entity may itself be a renaming_as_body. Used to enforce - -- rule that a renaming_as_body is illegal if the declaration occurs - -- before the subprogram it completes is frozen, and renaming indirectly - -- renames the subprogram itself.(Defect Report 8652/0027). - - -------------------------- - -- Check_Null_Exclusion -- - -------------------------- - - procedure Check_Null_Exclusion - (Ren : Entity_Id; - Sub : Entity_Id) - is - Ren_Formal : Entity_Id; - Sub_Formal : Entity_Id; - - begin - -- Parameter check - - Ren_Formal := First_Formal (Ren); - Sub_Formal := First_Formal (Sub); - while Present (Ren_Formal) - and then Present (Sub_Formal) - loop - if Has_Null_Exclusion (Parent (Ren_Formal)) - and then - not (Has_Null_Exclusion (Parent (Sub_Formal)) - or else Can_Never_Be_Null (Etype (Sub_Formal))) - then - Error_Msg_NE - ("`NOT NULL` required for parameter &", - Parent (Sub_Formal), Sub_Formal); - end if; - - Next_Formal (Ren_Formal); - Next_Formal (Sub_Formal); - end loop; - - -- Return profile check - - if Nkind (Parent (Ren)) = N_Function_Specification - and then Nkind (Parent (Sub)) = N_Function_Specification - and then Has_Null_Exclusion (Parent (Ren)) - and then - not (Has_Null_Exclusion (Parent (Sub)) - or else Can_Never_Be_Null (Etype (Sub))) - then - Error_Msg_N - ("return must specify `NOT NULL`", - Result_Definition (Parent (Sub))); - end if; - end Check_Null_Exclusion; - - ------------------------- - -- Original_Subprogram -- - ------------------------- - - function Original_Subprogram (Subp : Entity_Id) return Entity_Id is - Orig_Decl : Node_Id; - Orig_Subp : Entity_Id; - - begin - -- First case: renamed entity is itself a renaming - - if Present (Alias (Subp)) then - return Alias (Subp); - - elsif - Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration - and then Present - (Corresponding_Body (Unit_Declaration_Node (Subp))) - then - -- Check if renamed entity is a renaming_as_body - - Orig_Decl := - Unit_Declaration_Node - (Corresponding_Body (Unit_Declaration_Node (Subp))); - - if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then - Orig_Subp := Entity (Name (Orig_Decl)); - - if Orig_Subp = Rename_Spec then - - -- Circularity detected - - return Orig_Subp; - - else - return (Original_Subprogram (Orig_Subp)); - end if; - else - return Subp; - end if; - else - return Subp; - end if; - end Original_Subprogram; - - -- Start of processing for Analyze_Subprogram_Renaming - - begin - -- We must test for the attribute renaming case before the Analyze - -- call because otherwise Sem_Attr will complain that the attribute - -- is missing an argument when it is analyzed. - - if Nkind (Nam) = N_Attribute_Reference then - - -- In the case of an abstract formal subprogram association, rewrite - -- an actual given by a stream attribute as the name of the - -- corresponding stream primitive of the type. - - -- In a generic context the stream operations are not generated, and - -- this must be treated as a normal attribute reference, to be - -- expanded in subsequent instantiations. - - if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) - and then Expander_Active - then - declare - Stream_Prim : Entity_Id; - Prefix_Type : constant Entity_Id := Entity (Prefix (Nam)); - - begin - -- The class-wide forms of the stream attributes are not - -- primitive dispatching operations (even though they - -- internally dispatch to a stream attribute). - - if Is_Class_Wide_Type (Prefix_Type) then - Error_Msg_N - ("attribute must be a primitive dispatching operation", - Nam); - return; - end if; - - -- Retrieve the primitive subprogram associated with the - -- attribute. This can only be a stream attribute, since those - -- are the only ones that are dispatching (and the actual for - -- an abstract formal subprogram must be dispatching - -- operation). - - begin - case Attribute_Name (Nam) is - when Name_Input => - Stream_Prim := - Find_Prim_Op (Prefix_Type, TSS_Stream_Input); - when Name_Output => - Stream_Prim := - Find_Prim_Op (Prefix_Type, TSS_Stream_Output); - when Name_Read => - Stream_Prim := - Find_Prim_Op (Prefix_Type, TSS_Stream_Read); - when Name_Write => - Stream_Prim := - Find_Prim_Op (Prefix_Type, TSS_Stream_Write); - when others => - Error_Msg_N - ("attribute must be a primitive" - & " dispatching operation", Nam); - return; - end case; - - exception - - -- If no operation was found, and the type is limited, - -- the user should have defined one. - - when Program_Error => - if Is_Limited_Type (Prefix_Type) then - Error_Msg_NE - ("stream operation not defined for type&", - N, Prefix_Type); - return; - - -- Otherwise, compiler should have generated default - - else - raise; - end if; - end; - - -- Rewrite the attribute into the name of its corresponding - -- primitive dispatching subprogram. We can then proceed with - -- the usual processing for subprogram renamings. - - declare - Prim_Name : constant Node_Id := - Make_Identifier (Sloc (Nam), - Chars => Chars (Stream_Prim)); - begin - Set_Entity (Prim_Name, Stream_Prim); - Rewrite (Nam, Prim_Name); - Analyze (Nam); - end; - end; - - -- Normal processing for a renaming of an attribute - - else - Attribute_Renaming (N); - return; - end if; - end if; - - -- Check whether this declaration corresponds to the instantiation - -- of a formal subprogram. - - -- If this is an instantiation, the corresponding actual is frozen and - -- error messages can be made more precise. If this is a default - -- subprogram, the entity is already established in the generic, and is - -- not retrieved by visibility. If it is a default with a box, the - -- candidate interpretations, if any, have been collected when building - -- the renaming declaration. If overloaded, the proper interpretation is - -- determined in Find_Renamed_Entity. If the entity is an operator, - -- Find_Renamed_Entity applies additional visibility checks. - - if Is_Actual then - Inst_Node := Unit_Declaration_Node (Formal_Spec); - - if Is_Entity_Name (Nam) - and then Present (Entity (Nam)) - and then not Comes_From_Source (Nam) - and then not Is_Overloaded (Nam) - then - Old_S := Entity (Nam); - New_S := Analyze_Subprogram_Specification (Spec); - - -- Operator case - - if Ekind (Entity (Nam)) = E_Operator then - - -- Box present - - if Box_Present (Inst_Node) then - Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual); - - -- If there is an immediately visible homonym of the operator - -- and the declaration has a default, this is worth a warning - -- because the user probably did not intend to get the pre- - -- defined operator, visible in the generic declaration. To - -- find if there is an intended candidate, analyze the renaming - -- again in the current context. - - elsif Scope (Old_S) = Standard_Standard - and then Present (Default_Name (Inst_Node)) - then - declare - Decl : constant Node_Id := New_Copy_Tree (N); - Hidden : Entity_Id; - - begin - Set_Entity (Name (Decl), Empty); - Analyze (Name (Decl)); - Hidden := - Find_Renamed_Entity (Decl, Name (Decl), New_S, True); - - if Present (Hidden) - and then In_Open_Scopes (Scope (Hidden)) - and then Is_Immediately_Visible (Hidden) - and then Comes_From_Source (Hidden) - and then Hidden /= Old_S - then - Error_Msg_Sloc := Sloc (Hidden); - Error_Msg_N ("?default subprogram is resolved " & - "in the generic declaration " & - "(RM 12.6(17))", N); - Error_Msg_NE ("\?and will not use & #", N, Hidden); - end if; - end; - end if; - end if; - - else - Analyze (Nam); - New_S := Analyze_Subprogram_Specification (Spec); - end if; - - else - -- Renamed entity must be analyzed first, to avoid being hidden by - -- new name (which might be the same in a generic instance). - - Analyze (Nam); - - -- The renaming defines a new overloaded entity, which is analyzed - -- like a subprogram declaration. - - New_S := Analyze_Subprogram_Specification (Spec); - end if; - - if Current_Scope /= Standard_Standard then - Set_Is_Pure (New_S, Is_Pure (Current_Scope)); - end if; - - Rename_Spec := Find_Corresponding_Spec (N); - - -- Case of Renaming_As_Body - - if Present (Rename_Spec) then - - -- Renaming declaration is the completion of the declaration of - -- Rename_Spec. We build an actual body for it at the freezing point. - - Set_Corresponding_Spec (N, Rename_Spec); - - -- Deal with special case of stream functions of abstract types - -- and interfaces. - - if Nkind (Unit_Declaration_Node (Rename_Spec)) = - N_Abstract_Subprogram_Declaration - then - -- Input stream functions are abstract if the object type is - -- abstract. Similarly, all default stream functions for an - -- interface type are abstract. However, these subprograms may - -- receive explicit declarations in representation clauses, making - -- the attribute subprograms usable as defaults in subsequent - -- type extensions. - -- In this case we rewrite the declaration to make the subprogram - -- non-abstract. We remove the previous declaration, and insert - -- the new one at the point of the renaming, to prevent premature - -- access to unfrozen types. The new declaration reuses the - -- specification of the previous one, and must not be analyzed. - - pragma Assert - (Is_Primitive (Entity (Nam)) - and then - Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam)))); - declare - Old_Decl : constant Node_Id := - Unit_Declaration_Node (Rename_Spec); - New_Decl : constant Node_Id := - Make_Subprogram_Declaration (Sloc (N), - Specification => - Relocate_Node (Specification (Old_Decl))); - begin - Remove (Old_Decl); - Insert_After (N, New_Decl); - Set_Is_Abstract_Subprogram (Rename_Spec, False); - Set_Analyzed (New_Decl); - end; - end if; - - Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S); - - if Ada_Version = Ada_83 and then Comes_From_Source (N) then - Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N); - end if; - - Set_Convention (New_S, Convention (Rename_Spec)); - Check_Fully_Conformant (New_S, Rename_Spec); - Set_Public_Status (New_S); - - -- The specification does not introduce new formals, but only - -- repeats the formals of the original subprogram declaration. - -- For cross-reference purposes, and for refactoring tools, we - -- treat the formals of the renaming declaration as body formals. - - Reference_Body_Formals (Rename_Spec, New_S); - - -- Indicate that the entity in the declaration functions like the - -- corresponding body, and is not a new entity. The body will be - -- constructed later at the freeze point, so indicate that the - -- completion has not been seen yet. - - Set_Ekind (New_S, E_Subprogram_Body); - New_S := Rename_Spec; - Set_Has_Completion (Rename_Spec, False); - - -- Ada 2005: check overriding indicator - - if Is_Overriding_Operation (Rename_Spec) then - if Must_Not_Override (Specification (N)) then - Error_Msg_NE - ("subprogram& overrides inherited operation", - N, Rename_Spec); - elsif - Style_Check and then not Must_Override (Specification (N)) - then - Style.Missing_Overriding (N, Rename_Spec); - end if; - - elsif Must_Override (Specification (N)) then - Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec); - end if; - - -- Normal subprogram renaming (not renaming as body) - - else - Generate_Definition (New_S); - New_Overloaded_Entity (New_S); - - if Is_Entity_Name (Nam) - and then Is_Intrinsic_Subprogram (Entity (Nam)) - then - null; - else - Check_Delayed_Subprogram (New_S); - end if; - end if; - - -- There is no need for elaboration checks on the new entity, which may - -- be called before the next freezing point where the body will appear. - -- Elaboration checks refer to the real entity, not the one created by - -- the renaming declaration. - - Set_Kill_Elaboration_Checks (New_S, True); - - if Etype (Nam) = Any_Type then - Set_Has_Completion (New_S); - return; - - elsif Nkind (Nam) = N_Selected_Component then - - -- A prefix of the form A.B can designate an entry of task A, a - -- protected operation of protected object A, or finally a primitive - -- operation of object A. In the later case, A is an object of some - -- tagged type, or an access type that denotes one such. To further - -- distinguish these cases, note that the scope of a task entry or - -- protected operation is type of the prefix. - - -- The prefix could be an overloaded function call that returns both - -- kinds of operations. This overloading pathology is left to the - -- dedicated reader ??? - - declare - T : constant Entity_Id := Etype (Prefix (Nam)); - - begin - if Present (T) - and then - (Is_Tagged_Type (T) - or else - (Is_Access_Type (T) - and then - Is_Tagged_Type (Designated_Type (T)))) - and then Scope (Entity (Selector_Name (Nam))) /= T - then - Analyze_Renamed_Primitive_Operation - (N, New_S, Present (Rename_Spec)); - return; - - else - -- Renamed entity is an entry or protected operation. For those - -- cases an explicit body is built (at the point of freezing of - -- this entity) that contains a call to the renamed entity. - - -- This is not allowed for renaming as body if the renamed - -- spec is already frozen (see RM 8.5.4(5) for details). - - if Present (Rename_Spec) - and then Is_Frozen (Rename_Spec) - then - Error_Msg_N - ("renaming-as-body cannot rename entry as subprogram", N); - Error_Msg_NE - ("\since & is already frozen (RM 8.5.4(5))", - N, Rename_Spec); - else - Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec)); - end if; - - return; - end if; - end; - - elsif Nkind (Nam) = N_Explicit_Dereference then - - -- Renamed entity is designated by access_to_subprogram expression. - -- Must build body to encapsulate call, as in the entry case. - - Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec)); - return; - - elsif Nkind (Nam) = N_Indexed_Component then - Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec)); - return; - - elsif Nkind (Nam) = N_Character_Literal then - Analyze_Renamed_Character (N, New_S, Present (Rename_Spec)); - return; - - elsif (not Is_Entity_Name (Nam) - and then Nkind (Nam) /= N_Operator_Symbol) - or else not Is_Overloadable (Entity (Nam)) - then - Error_Msg_N ("expect valid subprogram name in renaming", N); - return; - end if; - - -- Find the renamed entity that matches the given specification. Disable - -- Ada_83 because there is no requirement of full conformance between - -- renamed entity and new entity, even though the same circuit is used. - - -- This is a bit of a kludge, which introduces a really irregular use of - -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this - -- ??? - - Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95); - Ada_Version_Explicit := Ada_Version; - - if No (Old_S) then - Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual); - - -- When the renamed subprogram is overloaded and used as an actual - -- of a generic, its entity is set to the first available homonym. - -- We must first disambiguate the name, then set the proper entity. - - if Is_Actual - and then Is_Overloaded (Nam) - then - Set_Entity (Nam, Old_S); - end if; - end if; - - -- Most common case: subprogram renames subprogram. No body is generated - -- in this case, so we must indicate the declaration is complete as is. - -- and inherit various attributes of the renamed subprogram. - - if No (Rename_Spec) then - Set_Has_Completion (New_S); - Set_Is_Imported (New_S, Is_Imported (Entity (Nam))); - Set_Is_Pure (New_S, Is_Pure (Entity (Nam))); - Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam))); - - -- Ada 2005 (AI-423): Check the consistency of null exclusions - -- between a subprogram and its correct renaming. - - -- Note: the Any_Id check is a guard that prevents compiler crashes - -- when performing a null exclusion check between a renaming and a - -- renamed subprogram that has been found to be illegal. - - if Ada_Version >= Ada_05 - and then Entity (Nam) /= Any_Id - then - Check_Null_Exclusion - (Ren => New_S, - Sub => Entity (Nam)); - end if; - - -- Enforce the Ada 2005 rule that the renamed entity cannot require - -- overriding. The flag Requires_Overriding is set very selectively - -- and misses some other illegal cases. The additional conditions - -- checked below are sufficient but not necessary ??? - - -- The rule does not apply to the renaming generated for an actual - -- subprogram in an instance. - - if Is_Actual then - null; - - -- Guard against previous errors, and omit renamings of predefined - -- operators. - - elsif Ekind (Old_S) /= E_Function - and then Ekind (Old_S) /= E_Procedure - then - null; - - elsif Requires_Overriding (Old_S) - or else - (Is_Abstract_Subprogram (Old_S) - and then Present (Find_Dispatching_Type (Old_S)) - and then - not Is_Abstract_Type (Find_Dispatching_Type (Old_S))) - then - Error_Msg_N - ("renamed entity cannot be " - & "subprogram that requires overriding (RM 8.5.4 (5.1))", N); - end if; - end if; - - if Old_S /= Any_Id then - if Is_Actual - and then From_Default (N) - then - -- This is an implicit reference to the default actual - - Generate_Reference (Old_S, Nam, Typ => 'i', Force => True); - else - Generate_Reference (Old_S, Nam); - end if; - - -- For a renaming-as-body, require subtype conformance, but if the - -- declaration being completed has not been frozen, then inherit the - -- convention of the renamed subprogram prior to checking conformance - -- (unless the renaming has an explicit convention established; the - -- rule stated in the RM doesn't seem to address this ???). - - if Present (Rename_Spec) then - Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b'); - Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec); - - if not Is_Frozen (Rename_Spec) then - if not Has_Convention_Pragma (Rename_Spec) then - Set_Convention (New_S, Convention (Old_S)); - end if; - - if Ekind (Old_S) /= E_Operator then - Check_Mode_Conformant (New_S, Old_S, Spec); - end if; - - if Original_Subprogram (Old_S) = Rename_Spec then - Error_Msg_N ("unfrozen subprogram cannot rename itself ", N); - end if; - else - Check_Subtype_Conformant (New_S, Old_S, Spec); - end if; - - Check_Frozen_Renaming (N, Rename_Spec); - - -- Check explicitly that renamed entity is not intrinsic, because - -- in a generic the renamed body is not built. In this case, - -- the renaming_as_body is a completion. - - if Inside_A_Generic then - if Is_Frozen (Rename_Spec) - and then Is_Intrinsic_Subprogram (Old_S) - then - Error_Msg_N - ("subprogram in renaming_as_body cannot be intrinsic", - Name (N)); - end if; - - Set_Has_Completion (Rename_Spec); - end if; - - elsif Ekind (Old_S) /= E_Operator then - Check_Mode_Conformant (New_S, Old_S); - - if Is_Actual - and then Error_Posted (New_S) - then - Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S); - end if; - end if; - - if No (Rename_Spec) then - - -- The parameter profile of the new entity is that of the renamed - -- entity: the subtypes given in the specification are irrelevant. - - Inherit_Renamed_Profile (New_S, Old_S); - - -- A call to the subprogram is transformed into a call to the - -- renamed entity. This is transitive if the renamed entity is - -- itself a renaming. - - if Present (Alias (Old_S)) then - Set_Alias (New_S, Alias (Old_S)); - else - Set_Alias (New_S, Old_S); - end if; - - -- Note that we do not set Is_Intrinsic_Subprogram if we have a - -- renaming as body, since the entity in this case is not an - -- intrinsic (it calls an intrinsic, but we have a real body for - -- this call, and it is in this body that the required intrinsic - -- processing will take place). - - -- Also, if this is a renaming of inequality, the renamed operator - -- is intrinsic, but what matters is the corresponding equality - -- operator, which may be user-defined. - - Set_Is_Intrinsic_Subprogram - (New_S, - Is_Intrinsic_Subprogram (Old_S) - and then - (Chars (Old_S) /= Name_Op_Ne - or else Ekind (Old_S) = E_Operator - or else - Is_Intrinsic_Subprogram - (Corresponding_Equality (Old_S)))); - - if Ekind (Alias (New_S)) = E_Operator then - Set_Has_Delayed_Freeze (New_S, False); - end if; - - -- If the renaming corresponds to an association for an abstract - -- formal subprogram, then various attributes must be set to - -- indicate that the renaming is an abstract dispatching operation - -- with a controlling type. - - if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then - - -- Mark the renaming as abstract here, so Find_Dispatching_Type - -- see it as corresponding to a generic association for a - -- formal abstract subprogram - - Set_Is_Abstract_Subprogram (New_S); - - declare - New_S_Ctrl_Type : constant Entity_Id := - Find_Dispatching_Type (New_S); - Old_S_Ctrl_Type : constant Entity_Id := - Find_Dispatching_Type (Old_S); - - begin - if Old_S_Ctrl_Type /= New_S_Ctrl_Type then - Error_Msg_NE - ("actual must be dispatching subprogram for type&", - Nam, New_S_Ctrl_Type); - - else - Set_Is_Dispatching_Operation (New_S); - Check_Controlling_Formals (New_S_Ctrl_Type, New_S); - - -- If the actual in the formal subprogram is itself a - -- formal abstract subprogram association, there's no - -- dispatch table component or position to inherit. - - if Present (DTC_Entity (Old_S)) then - Set_DTC_Entity (New_S, DTC_Entity (Old_S)); - Set_DT_Position (New_S, DT_Position (Old_S)); - end if; - end if; - end; - end if; - end if; - - if not Is_Actual - and then (Old_S = New_S - or else (Nkind (Nam) /= N_Expanded_Name - and then Chars (Old_S) = Chars (New_S))) - then - Error_Msg_N ("subprogram cannot rename itself", N); - end if; - - Set_Convention (New_S, Convention (Old_S)); - - if Is_Abstract_Subprogram (Old_S) then - if Present (Rename_Spec) then - Error_Msg_N - ("a renaming-as-body cannot rename an abstract subprogram", - N); - Set_Has_Completion (Rename_Spec); - else - Set_Is_Abstract_Subprogram (New_S); - end if; - end if; - - Check_Library_Unit_Renaming (N, Old_S); - - -- Pathological case: procedure renames entry in the scope of its - -- task. Entry is given by simple name, but body must be built for - -- procedure. Of course if called it will deadlock. - - if Ekind (Old_S) = E_Entry then - Set_Has_Completion (New_S, False); - Set_Alias (New_S, Empty); - end if; - - if Is_Actual then - Freeze_Before (N, Old_S); - Set_Has_Delayed_Freeze (New_S, False); - Freeze_Before (N, New_S); - - -- An abstract subprogram is only allowed as an actual in the case - -- where the formal subprogram is also abstract. - - if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function) - and then Is_Abstract_Subprogram (Old_S) - and then not Is_Abstract_Subprogram (Formal_Spec) - then - Error_Msg_N - ("abstract subprogram not allowed as generic actual", Nam); - end if; - end if; - - else - -- A common error is to assume that implicit operators for types are - -- defined in Standard, or in the scope of a subtype. In those cases - -- where the renamed entity is given with an expanded name, it is - -- worth mentioning that operators for the type are not declared in - -- the scope given by the prefix. - - if Nkind (Nam) = N_Expanded_Name - and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol - and then Scope (Entity (Nam)) = Standard_Standard - then - declare - T : constant Entity_Id := - Base_Type (Etype (First_Formal (New_S))); - begin - Error_Msg_Node_2 := Prefix (Nam); - Error_Msg_NE - ("operator for type& is not declared in&", Prefix (Nam), T); - end; - - else - Error_Msg_NE - ("no visible subprogram matches the specification for&", - Spec, New_S); - end if; - - if Present (Candidate_Renaming) then - declare - F1 : Entity_Id; - F2 : Entity_Id; - - begin - F1 := First_Formal (Candidate_Renaming); - F2 := First_Formal (New_S); - - while Present (F1) and then Present (F2) loop - Next_Formal (F1); - Next_Formal (F2); - end loop; - - if Present (F1) and then Present (Default_Value (F1)) then - if Present (Next_Formal (F1)) then - Error_Msg_NE - ("\missing specification for &" & - " and other formals with defaults", Spec, F1); - else - Error_Msg_NE - ("\missing specification for &", Spec, F1); - end if; - end if; - end; - end if; - end if; - - -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that - -- controlling access parameters are known non-null for the renamed - -- subprogram. Test also applies to a subprogram instantiation that - -- is dispatching. Test is skipped if some previous error was detected - -- that set Old_S to Any_Id. - - if Ada_Version >= Ada_05 - and then Old_S /= Any_Id - and then not Is_Dispatching_Operation (Old_S) - and then Is_Dispatching_Operation (New_S) - then - declare - Old_F : Entity_Id; - New_F : Entity_Id; - - begin - Old_F := First_Formal (Old_S); - New_F := First_Formal (New_S); - while Present (Old_F) loop - if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type - and then Is_Controlling_Formal (New_F) - and then not Can_Never_Be_Null (Old_F) - then - Error_Msg_N ("access parameter is controlling,", New_F); - Error_Msg_NE - ("\corresponding parameter of& " - & "must be explicitly null excluding", New_F, Old_S); - end if; - - Next_Formal (Old_F); - Next_Formal (New_F); - end loop; - end; - end if; - - -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005) - - if Comes_From_Source (N) - and then Present (Old_S) - and then Nkind (Old_S) = N_Defining_Operator_Symbol - and then Nkind (New_S) = N_Defining_Operator_Symbol - and then Chars (Old_S) /= Chars (New_S) - then - Error_Msg_NE - ("?& is being renamed as a different operator", - New_S, Old_S); - end if; - - -- Another warning or some utility: if the new subprogram as the same - -- name as the old one, the old one is not hidden by an outer homograph, - -- the new one is not a public symbol, and the old one is otherwise - -- directly visible, the renaming is superfluous. - - if Chars (Old_S) = Chars (New_S) - and then Comes_From_Source (N) - and then Scope (Old_S) /= Standard_Standard - and then Warn_On_Redundant_Constructs - and then - (Is_Immediately_Visible (Old_S) - or else Is_Potentially_Use_Visible (Old_S)) - and then Is_Overloadable (Current_Scope) - and then Chars (Current_Scope) /= Chars (Old_S) - then - Error_Msg_N - ("?redundant renaming, entity is directly visible", Name (N)); - end if; - - Ada_Version := Save_AV; - Ada_Version_Explicit := Save_AV_Exp; - end Analyze_Subprogram_Renaming; - - ------------------------- - -- Analyze_Use_Package -- - ------------------------- - - -- Resolve the package names in the use clause, and make all the visible - -- entities defined in the package potentially use-visible. If the package - -- is already in use from a previous use clause, its visible entities are - -- already use-visible. In that case, mark the occurrence as a redundant - -- use. If the package is an open scope, i.e. if the use clause occurs - -- within the package itself, ignore it. - - procedure Analyze_Use_Package (N : Node_Id) is - Pack_Name : Node_Id; - Pack : Entity_Id; - - -- Start of processing for Analyze_Use_Package - - begin - Set_Hidden_By_Use_Clause (N, No_Elist); - - -- Use clause is not allowed in a spec of a predefined package - -- declaration except that packages whose file name starts a-n are OK - -- (these are children of Ada.Numerics, and such packages are never - -- loaded by Rtsfind). - - if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit)) - and then Name_Buffer (1 .. 3) /= "a-n" - and then - Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration - then - Error_Msg_N ("use clause not allowed in predefined spec", N); - end if; - - -- Chain clause to list of use clauses in current scope - - if Nkind (Parent (N)) /= N_Compilation_Unit then - Chain_Use_Clause (N); - end if; - - -- Loop through package names to identify referenced packages - - Pack_Name := First (Names (N)); - while Present (Pack_Name) loop - Analyze (Pack_Name); - - if Nkind (Parent (N)) = N_Compilation_Unit - and then Nkind (Pack_Name) = N_Expanded_Name - then - declare - Pref : Node_Id; - - begin - Pref := Prefix (Pack_Name); - while Nkind (Pref) = N_Expanded_Name loop - Pref := Prefix (Pref); - end loop; - - if Entity (Pref) = Standard_Standard then - Error_Msg_N - ("predefined package Standard cannot appear" - & " in a context clause", Pref); - end if; - end; - end if; - - Next (Pack_Name); - end loop; - - -- Loop through package names to mark all entities as potentially - -- use visible. - - Pack_Name := First (Names (N)); - while Present (Pack_Name) loop - if Is_Entity_Name (Pack_Name) then - Pack := Entity (Pack_Name); - - if Ekind (Pack) /= E_Package - and then Etype (Pack) /= Any_Type - then - if Ekind (Pack) = E_Generic_Package then - Error_Msg_N - ("a generic package is not allowed in a use clause", - Pack_Name); - else - Error_Msg_N ("& is not a usable package", Pack_Name); - end if; - - else - if Nkind (Parent (N)) = N_Compilation_Unit then - Check_In_Previous_With_Clause (N, Pack_Name); - end if; - - if Applicable_Use (Pack_Name) then - Use_One_Package (Pack, N); - end if; - end if; - - -- Report error because name denotes something other than a package - - else - Error_Msg_N ("& is not a package", Pack_Name); - end if; - - Next (Pack_Name); - end loop; - end Analyze_Use_Package; - - ---------------------- - -- Analyze_Use_Type -- - ---------------------- - - procedure Analyze_Use_Type (N : Node_Id) is - E : Entity_Id; - Id : Entity_Id; - - begin - Set_Hidden_By_Use_Clause (N, No_Elist); - - -- Chain clause to list of use clauses in current scope - - if Nkind (Parent (N)) /= N_Compilation_Unit then - Chain_Use_Clause (N); - end if; - - Id := First (Subtype_Marks (N)); - while Present (Id) loop - Find_Type (Id); - E := Entity (Id); - - if E /= Any_Type then - Use_One_Type (Id); - - if Nkind (Parent (N)) = N_Compilation_Unit then - if Nkind (Id) = N_Identifier then - Error_Msg_N ("type is not directly visible", Id); - - elsif Is_Child_Unit (Scope (E)) - and then Scope (E) /= System_Aux_Id - then - Check_In_Previous_With_Clause (N, Prefix (Id)); - end if; - end if; - end if; - - Next (Id); - end loop; - end Analyze_Use_Type; - - -------------------- - -- Applicable_Use -- - -------------------- - - function Applicable_Use (Pack_Name : Node_Id) return Boolean is - Pack : constant Entity_Id := Entity (Pack_Name); - - begin - if In_Open_Scopes (Pack) then - if Warn_On_Redundant_Constructs - and then Pack = Current_Scope - then - Error_Msg_NE - ("& is already use-visible within itself?", Pack_Name, Pack); - end if; - - return False; - - elsif In_Use (Pack) then - Note_Redundant_Use (Pack_Name); - return False; - - elsif Present (Renamed_Object (Pack)) - and then In_Use (Renamed_Object (Pack)) - then - Note_Redundant_Use (Pack_Name); - return False; - - else - return True; - end if; - end Applicable_Use; - - ------------------------ - -- Attribute_Renaming -- - ------------------------ - - procedure Attribute_Renaming (N : Node_Id) is - Loc : constant Source_Ptr := Sloc (N); - Nam : constant Node_Id := Name (N); - Spec : constant Node_Id := Specification (N); - New_S : constant Entity_Id := Defining_Unit_Name (Spec); - Aname : constant Name_Id := Attribute_Name (Nam); - - Form_Num : Nat := 0; - Expr_List : List_Id := No_List; - - Attr_Node : Node_Id; - Body_Node : Node_Id; - Param_Spec : Node_Id; - - begin - Generate_Definition (New_S); - - -- This procedure is called in the context of subprogram renaming, - -- and thus the attribute must be one that is a subprogram. All of - -- those have at least one formal parameter, with the singular - -- exception of AST_Entry (which is a real oddity, it is odd that - -- this can be renamed at all!) - - if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then - if Aname /= Name_AST_Entry then - Error_Msg_N - ("subprogram renaming an attribute must have formals", N); - return; - end if; - - else - Param_Spec := First (Parameter_Specifications (Spec)); - while Present (Param_Spec) loop - Form_Num := Form_Num + 1; - - if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then - Find_Type (Parameter_Type (Param_Spec)); - - -- The profile of the new entity denotes the base type (s) of - -- the types given in the specification. For access parameters - -- there are no subtypes involved. - - Rewrite (Parameter_Type (Param_Spec), - New_Reference_To - (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc)); - end if; - - if No (Expr_List) then - Expr_List := New_List; - end if; - - Append_To (Expr_List, - Make_Identifier (Loc, - Chars => Chars (Defining_Identifier (Param_Spec)))); - - -- The expressions in the attribute reference are not freeze - -- points. Neither is the attribute as a whole, see below. - - Set_Must_Not_Freeze (Last (Expr_List)); - Next (Param_Spec); - end loop; - end if; - - -- Immediate error if too many formals. Other mismatches in numbers - -- of number of types of parameters are detected when we analyze the - -- body of the subprogram that we construct. - - if Form_Num > 2 then - Error_Msg_N ("too many formals for attribute", N); - - -- Error if the attribute reference has expressions that look - -- like formal parameters. - - elsif Present (Expressions (Nam)) then - Error_Msg_N ("illegal expressions in attribute reference", Nam); - - elsif - Aname = Name_Compose or else - Aname = Name_Exponent or else - Aname = Name_Leading_Part or else - Aname = Name_Pos or else - Aname = Name_Round or else - Aname = Name_Scaling or else - Aname = Name_Val - then - if Nkind (N) = N_Subprogram_Renaming_Declaration - and then Present (Corresponding_Formal_Spec (N)) - then - Error_Msg_N - ("generic actual cannot be attribute involving universal type", - Nam); - else - Error_Msg_N - ("attribute involving a universal type cannot be renamed", - Nam); - end if; - end if; - - -- AST_Entry is an odd case. It doesn't really make much sense to - -- allow it to be renamed, but that's the DEC rule, so we have to - -- do it right. The point is that the AST_Entry call should be made - -- now, and what the function will return is the returned value. - - -- Note that there is no Expr_List in this case anyway - - if Aname = Name_AST_Entry then - declare - Ent : Entity_Id; - Decl : Node_Id; - - begin - Ent := Make_Defining_Identifier (Loc, New_Internal_Name ('R')); - - Decl := - Make_Object_Declaration (Loc, - Defining_Identifier => Ent, - Object_Definition => - New_Occurrence_Of (RTE (RE_AST_Handler), Loc), - Expression => Nam, - Constant_Present => True); - - Set_Assignment_OK (Decl, True); - Insert_Action (N, Decl); - Attr_Node := Make_Identifier (Loc, Chars (Ent)); - end; - - -- For all other attributes, we rewrite the attribute node to have - -- a list of expressions corresponding to the subprogram formals. - -- A renaming declaration is not a freeze point, and the analysis of - -- the attribute reference should not freeze the type of the prefix. - - else - Attr_Node := - Make_Attribute_Reference (Loc, - Prefix => Prefix (Nam), - Attribute_Name => Aname, - Expressions => Expr_List); - - Set_Must_Not_Freeze (Attr_Node); - Set_Must_Not_Freeze (Prefix (Nam)); - end if; - - -- Case of renaming a function - - if Nkind (Spec) = N_Function_Specification then - if Is_Procedure_Attribute_Name (Aname) then - Error_Msg_N ("attribute can only be renamed as procedure", Nam); - return; - end if; - - Find_Type (Result_Definition (Spec)); - Rewrite (Result_Definition (Spec), - New_Reference_To ( - Base_Type (Entity (Result_Definition (Spec))), Loc)); - - Body_Node := - Make_Subprogram_Body (Loc, - Specification => Spec, - Declarations => New_List, - Handled_Statement_Sequence => - Make_Handled_Sequence_Of_Statements (Loc, - Statements => New_List ( - Make_Simple_Return_Statement (Loc, - Expression => Attr_Node)))); - - -- Case of renaming a procedure - - else - if not Is_Procedure_Attribute_Name (Aname) then - Error_Msg_N ("attribute can only be renamed as function", Nam); - return; - end if; - - Body_Node := - Make_Subprogram_Body (Loc, - Specification => Spec, - Declarations => New_List, - Handled_Statement_Sequence => - Make_Handled_Sequence_Of_Statements (Loc, - Statements => New_List (Attr_Node))); - end if; - - -- In case of tagged types we add the body of the generated function to - -- the freezing actions of the type (because in the general case such - -- type is still not frozen). We exclude from this processing generic - -- formal subprograms found in instantiations and AST_Entry renamings. - - if not Present (Corresponding_Formal_Spec (N)) - and then Etype (Nam) /= RTE (RE_AST_Handler) - then - declare - P : constant Entity_Id := Prefix (Nam); - - begin - Find_Type (P); - - if Is_Tagged_Type (Etype (P)) then - Ensure_Freeze_Node (Etype (P)); - Append_Freeze_Action (Etype (P), Body_Node); - else - Rewrite (N, Body_Node); - Analyze (N); - Set_Etype (New_S, Base_Type (Etype (New_S))); - end if; - end; - - -- Generic formal subprograms or AST_Handler renaming - - else - Rewrite (N, Body_Node); - Analyze (N); - Set_Etype (New_S, Base_Type (Etype (New_S))); - end if; - - if Is_Compilation_Unit (New_S) then - Error_Msg_N - ("a library unit can only rename another library unit", N); - end if; - - -- We suppress elaboration warnings for the resulting entity, since - -- clearly they are not needed, and more particularly, in the case - -- of a generic formal subprogram, the resulting entity can appear - -- after the instantiation itself, and thus look like a bogus case - -- of access before elaboration. - - Set_Suppress_Elaboration_Warnings (New_S); - - end Attribute_Renaming; - - ---------------------- - -- Chain_Use_Clause -- - ---------------------- - - procedure Chain_Use_Clause (N : Node_Id) is - Pack : Entity_Id; - Level : Int := Scope_Stack.Last; - - begin - if not Is_Compilation_Unit (Current_Scope) - or else not Is_Child_Unit (Current_Scope) - then - null; -- Common case - - elsif Defining_Entity (Parent (N)) = Current_Scope then - null; -- Common case for compilation unit - - else - -- If declaration appears in some other scope, it must be in some - -- parent unit when compiling a child. - - Pack := Defining_Entity (Parent (N)); - if not In_Open_Scopes (Pack) then - null; -- default as well - - else - -- Find entry for parent unit in scope stack - - while Scope_Stack.Table (Level).Entity /= Pack loop - Level := Level - 1; - end loop; - end if; - end if; - - Set_Next_Use_Clause (N, - Scope_Stack.Table (Level).First_Use_Clause); - Scope_Stack.Table (Level).First_Use_Clause := N; - end Chain_Use_Clause; - - --------------------------- - -- Check_Frozen_Renaming -- - --------------------------- - - procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is - B_Node : Node_Id; - Old_S : Entity_Id; - - begin - if Is_Frozen (Subp) - and then not Has_Completion (Subp) - then - B_Node := - Build_Renamed_Body - (Parent (Declaration_Node (Subp)), Defining_Entity (N)); - - if Is_Entity_Name (Name (N)) then - Old_S := Entity (Name (N)); - - if not Is_Frozen (Old_S) - and then Operating_Mode /= Check_Semantics - then - Append_Freeze_Action (Old_S, B_Node); - else - Insert_After (N, B_Node); - Analyze (B_Node); - end if; - - if Is_Intrinsic_Subprogram (Old_S) - and then not In_Instance - then - Error_Msg_N - ("subprogram used in renaming_as_body cannot be intrinsic", - Name (N)); - end if; - - else - Insert_After (N, B_Node); - Analyze (B_Node); - end if; - end if; - end Check_Frozen_Renaming; - - ----------------------------------- - -- Check_In_Previous_With_Clause -- - ----------------------------------- - - procedure Check_In_Previous_With_Clause - (N : Node_Id; - Nam : Entity_Id) - is - Pack : constant Entity_Id := Entity (Original_Node (Nam)); - Item : Node_Id; - Par : Node_Id; - - begin - Item := First (Context_Items (Parent (N))); - - while Present (Item) - and then Item /= N - loop - if Nkind (Item) = N_With_Clause - - -- Protect the frontend against previous critical errors - - and then Nkind (Name (Item)) /= N_Selected_Component - and then Entity (Name (Item)) = Pack - then - Par := Nam; - - -- Find root library unit in with_clause - - while Nkind (Par) = N_Expanded_Name loop - Par := Prefix (Par); - end loop; - - if Is_Child_Unit (Entity (Original_Node (Par))) then - Error_Msg_NE - ("& is not directly visible", Par, Entity (Par)); - else - return; - end if; - end if; - - Next (Item); - end loop; - - -- On exit, package is not mentioned in a previous with_clause. - -- Check if its prefix is. - - if Nkind (Nam) = N_Expanded_Name then - Check_In_Previous_With_Clause (N, Prefix (Nam)); - - elsif Pack /= Any_Id then - Error_Msg_NE ("& is not visible", Nam, Pack); - end if; - end Check_In_Previous_With_Clause; - - --------------------------------- - -- Check_Library_Unit_Renaming -- - --------------------------------- - - procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is - New_E : Entity_Id; - - begin - if Nkind (Parent (N)) /= N_Compilation_Unit then - return; - - -- Check for library unit. Note that we used to check for the scope - -- being Standard here, but that was wrong for Standard itself. - - elsif not Is_Compilation_Unit (Old_E) - and then not Is_Child_Unit (Old_E) - then - Error_Msg_N ("renamed unit must be a library unit", Name (N)); - - -- Entities defined in Standard (operators and boolean literals) cannot - -- be renamed as library units. - - elsif Scope (Old_E) = Standard_Standard - and then Sloc (Old_E) = Standard_Location - then - Error_Msg_N ("renamed unit must be a library unit", Name (N)); - - elsif Present (Parent_Spec (N)) - and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration - and then not Is_Child_Unit (Old_E) - then - Error_Msg_N - ("renamed unit must be a child unit of generic parent", Name (N)); - - elsif Nkind (N) in N_Generic_Renaming_Declaration - and then Nkind (Name (N)) = N_Expanded_Name - and then Is_Generic_Instance (Entity (Prefix (Name (N)))) - and then Is_Generic_Unit (Old_E) - then - Error_Msg_N - ("renamed generic unit must be a library unit", Name (N)); - - elsif Is_Package_Or_Generic_Package (Old_E) then - - -- Inherit categorization flags - - New_E := Defining_Entity (N); - Set_Is_Pure (New_E, Is_Pure (Old_E)); - Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E)); - Set_Is_Remote_Call_Interface (New_E, - Is_Remote_Call_Interface (Old_E)); - Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E)); - Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E)); - end if; - end Check_Library_Unit_Renaming; - - --------------- - -- End_Scope -- - --------------- - - procedure End_Scope is - Id : Entity_Id; - Prev : Entity_Id; - Outer : Entity_Id; - - begin - Id := First_Entity (Current_Scope); - while Present (Id) loop - -- An entity in the current scope is not necessarily the first one - -- on its homonym chain. Find its predecessor if any, - -- If it is an internal entity, it will not be in the visibility - -- chain altogether, and there is nothing to unchain. - - if Id /= Current_Entity (Id) then - Prev := Current_Entity (Id); - while Present (Prev) - and then Present (Homonym (Prev)) - and then Homonym (Prev) /= Id - loop - Prev := Homonym (Prev); - end loop; - - -- Skip to end of loop if Id is not in the visibility chain - - if No (Prev) or else Homonym (Prev) /= Id then - goto Next_Ent; - end if; - - else - Prev := Empty; - end if; - - Set_Is_Immediately_Visible (Id, False); - - Outer := Homonym (Id); - while Present (Outer) and then Scope (Outer) = Current_Scope loop - Outer := Homonym (Outer); - end loop; - - -- Reset homonym link of other entities, but do not modify link - -- between entities in current scope, so that the back-end can have - -- a proper count of local overloadings. - - if No (Prev) then - Set_Name_Entity_Id (Chars (Id), Outer); - - elsif Scope (Prev) /= Scope (Id) then - Set_Homonym (Prev, Outer); - end if; - - <<Next_Ent>> - Next_Entity (Id); - end loop; - - -- If the scope generated freeze actions, place them before the - -- current declaration and analyze them. Type declarations and - -- the bodies of initialization procedures can generate such nodes. - -- We follow the parent chain until we reach a list node, which is - -- the enclosing list of declarations. If the list appears within - -- a protected definition, move freeze nodes outside the protected - -- type altogether. - - if Present - (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions) - then - declare - Decl : Node_Id; - L : constant List_Id := Scope_Stack.Table - (Scope_Stack.Last).Pending_Freeze_Actions; - - begin - if Is_Itype (Current_Scope) then - Decl := Associated_Node_For_Itype (Current_Scope); - else - Decl := Parent (Current_Scope); - end if; - - Pop_Scope; - - while not (Is_List_Member (Decl)) - or else Nkind_In (Parent (Decl), N_Protected_Definition, - N_Task_Definition) - loop - Decl := Parent (Decl); - end loop; - - Insert_List_Before_And_Analyze (Decl, L); - end; - - else - Pop_Scope; - end if; - - end End_Scope; - - --------------------- - -- End_Use_Clauses -- - --------------------- - - procedure End_Use_Clauses (Clause : Node_Id) is - U : Node_Id; - - begin - -- Remove Use_Type clauses first, because they affect the - -- visibility of operators in subsequent used packages. - - U := Clause; - while Present (U) loop - if Nkind (U) = N_Use_Type_Clause then - End_Use_Type (U); - end if; - - Next_Use_Clause (U); - end loop; - - U := Clause; - while Present (U) loop - if Nkind (U) = N_Use_Package_Clause then - End_Use_Package (U); - end if; - - Next_Use_Clause (U); - end loop; - end End_Use_Clauses; - - --------------------- - -- End_Use_Package -- - --------------------- - - procedure End_Use_Package (N : Node_Id) is - Pack_Name : Node_Id; - Pack : Entity_Id; - Id : Entity_Id; - Elmt : Elmt_Id; - - function Is_Primitive_Operator - (Op : Entity_Id; - F : Entity_Id) return Boolean; - -- Check whether Op is a primitive operator of a use-visible type - - --------------------------- - -- Is_Primitive_Operator -- - --------------------------- - - function Is_Primitive_Operator - (Op : Entity_Id; - F : Entity_Id) return Boolean - is - T : constant Entity_Id := Etype (F); - begin - return In_Use (T) - and then Scope (T) = Scope (Op); - end Is_Primitive_Operator; - - -- Start of processing for End_Use_Package - - begin - Pack_Name := First (Names (N)); - while Present (Pack_Name) loop - - -- Test that Pack_Name actually denotes a package before processing - - if Is_Entity_Name (Pack_Name) - and then Ekind (Entity (Pack_Name)) = E_Package - then - Pack := Entity (Pack_Name); - - if In_Open_Scopes (Pack) then - null; - - elsif not Redundant_Use (Pack_Name) then - Set_In_Use (Pack, False); - Set_Current_Use_Clause (Pack, Empty); - - Id := First_Entity (Pack); - while Present (Id) loop - - -- Preserve use-visibility of operators that are primitive - -- operators of a type that is use-visible through an active - -- use_type clause. - - if Nkind (Id) = N_Defining_Operator_Symbol - and then - (Is_Primitive_Operator (Id, First_Formal (Id)) - or else - (Present (Next_Formal (First_Formal (Id))) - and then - Is_Primitive_Operator - (Id, Next_Formal (First_Formal (Id))))) - then - null; - - else - Set_Is_Potentially_Use_Visible (Id, False); - end if; - - if Is_Private_Type (Id) - and then Present (Full_View (Id)) - then - Set_Is_Potentially_Use_Visible (Full_View (Id), False); - end if; - - Next_Entity (Id); - end loop; - - if Present (Renamed_Object (Pack)) then - Set_In_Use (Renamed_Object (Pack), False); - Set_Current_Use_Clause (Renamed_Object (Pack), Empty); - end if; - - if Chars (Pack) = Name_System - and then Scope (Pack) = Standard_Standard - and then Present_System_Aux - then - Id := First_Entity (System_Aux_Id); - while Present (Id) loop - Set_Is_Potentially_Use_Visible (Id, False); - - if Is_Private_Type (Id) - and then Present (Full_View (Id)) - then - Set_Is_Potentially_Use_Visible (Full_View (Id), False); - end if; - - Next_Entity (Id); - end loop; - - Set_In_Use (System_Aux_Id, False); - end if; - - else - Set_Redundant_Use (Pack_Name, False); - end if; - end if; - - Next (Pack_Name); - end loop; - - if Present (Hidden_By_Use_Clause (N)) then - Elmt := First_Elmt (Hidden_By_Use_Clause (N)); - while Present (Elmt) loop - Set_Is_Immediately_Visible (Node (Elmt)); - Next_Elmt (Elmt); - end loop; - - Set_Hidden_By_Use_Clause (N, No_Elist); - end if; - end End_Use_Package; - - ------------------ - -- End_Use_Type -- - ------------------ - - procedure End_Use_Type (N : Node_Id) is - Id : Entity_Id; - Op_List : Elist_Id; - Elmt : Elmt_Id; - T : Entity_Id; - - begin - Id := First (Subtype_Marks (N)); - while Present (Id) loop - - -- A call to rtsfind may occur while analyzing a use_type clause, - -- in which case the type marks are not resolved yet, and there is - -- nothing to remove. - - if not Is_Entity_Name (Id) - or else No (Entity (Id)) - then - goto Continue; - end if; - - T := Entity (Id); - - if T = Any_Type - or else From_With_Type (T) - then - null; - - -- Note that the use_Type clause may mention a subtype of the type - -- whose primitive operations have been made visible. Here as - -- elsewhere, it is the base type that matters for visibility. - - elsif In_Open_Scopes (Scope (Base_Type (T))) then - null; - - elsif not Redundant_Use (Id) then - Set_In_Use (T, False); - Set_In_Use (Base_Type (T), False); - Set_Current_Use_Clause (T, Empty); - Set_Current_Use_Clause (Base_Type (T), Empty); - Op_List := Collect_Primitive_Operations (T); - - Elmt := First_Elmt (Op_List); - while Present (Elmt) loop - if Nkind (Node (Elmt)) = N_Defining_Operator_Symbol then - Set_Is_Potentially_Use_Visible (Node (Elmt), False); - end if; - - Next_Elmt (Elmt); - end loop; - end if; - - <<Continue>> - Next (Id); - end loop; - end End_Use_Type; - - ---------------------- - -- Find_Direct_Name -- - ---------------------- - - procedure Find_Direct_Name (N : Node_Id) is - E : Entity_Id; - E2 : Entity_Id; - Msg : Boolean; - - Inst : Entity_Id := Empty; - -- Enclosing instance, if any - - Homonyms : Entity_Id; - -- Saves start of homonym chain - - Nvis_Entity : Boolean; - -- Set True to indicate that at there is at least one entity on the - -- homonym chain which, while not visible, is visible enough from the - -- user point of view to warrant an error message of "not visible" - -- rather than undefined. - - Nvis_Is_Private_Subprg : Boolean := False; - -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais - -- effect concerning library subprograms has been detected. Used to - -- generate the precise error message. - - function From_Actual_Package (E : Entity_Id) return Boolean; - -- Returns true if the entity is declared in a package that is - -- an actual for a formal package of the current instance. Such an - -- entity requires special handling because it may be use-visible - -- but hides directly visible entities defined outside the instance. - - function Is_Actual_Parameter return Boolean; - -- This function checks if the node N is an identifier that is an actual - -- parameter of a procedure call. If so it returns True, otherwise it - -- return False. The reason for this check is that at this stage we do - -- not know what procedure is being called if the procedure might be - -- overloaded, so it is premature to go setting referenced flags or - -- making calls to Generate_Reference. We will wait till Resolve_Actuals - -- for that processing - - function Known_But_Invisible (E : Entity_Id) return Boolean; - -- This function determines whether the entity E (which is not - -- visible) can reasonably be considered to be known to the writer - -- of the reference. This is a heuristic test, used only for the - -- purposes of figuring out whether we prefer to complain that an - -- entity is undefined or invisible (and identify the declaration - -- of the invisible entity in the latter case). The point here is - -- that we don't want to complain that something is invisible and - -- then point to something entirely mysterious to the writer. - - procedure Nvis_Messages; - -- Called if there are no visible entries for N, but there is at least - -- one non-directly visible, or hidden declaration. This procedure - -- outputs an appropriate set of error messages. - - procedure Undefined (Nvis : Boolean); - -- This function is called if the current node has no corresponding - -- visible entity or entities. The value set in Msg indicates whether - -- an error message was generated (multiple error messages for the - -- same variable are generally suppressed, see body for details). - -- Msg is True if an error message was generated, False if not. This - -- value is used by the caller to determine whether or not to output - -- additional messages where appropriate. The parameter is set False - -- to get the message "X is undefined", and True to get the message - -- "X is not visible". - - ------------------------- - -- From_Actual_Package -- - ------------------------- - - function From_Actual_Package (E : Entity_Id) return Boolean is - Scop : constant Entity_Id := Scope (E); - Act : Entity_Id; - - begin - if not In_Instance then - return False; - else - Inst := Current_Scope; - while Present (Inst) - and then Ekind (Inst) /= E_Package - and then not Is_Generic_Instance (Inst) - loop - Inst := Scope (Inst); - end loop; - - if No (Inst) then - return False; - end if; - - Act := First_Entity (Inst); - while Present (Act) loop - if Ekind (Act) = E_Package then - - -- Check for end of actuals list - - if Renamed_Object (Act) = Inst then - return False; - - elsif Present (Associated_Formal_Package (Act)) - and then Renamed_Object (Act) = Scop - then - -- Entity comes from (instance of) formal package - - return True; - - else - Next_Entity (Act); - end if; - - else - Next_Entity (Act); - end if; - end loop; - - return False; - end if; - end From_Actual_Package; - - ------------------------- - -- Is_Actual_Parameter -- - ------------------------- - - function Is_Actual_Parameter return Boolean is - begin - return - Nkind (N) = N_Identifier - and then - (Nkind (Parent (N)) = N_Procedure_Call_Statement - or else - (Nkind (Parent (N)) = N_Parameter_Association - and then N = Explicit_Actual_Parameter (Parent (N)) - and then Nkind (Parent (Parent (N))) = - N_Procedure_Call_Statement)); - end Is_Actual_Parameter; - - ------------------------- - -- Known_But_Invisible -- - ------------------------- - - function Known_But_Invisible (E : Entity_Id) return Boolean is - Fname : File_Name_Type; - - begin - -- Entities in Standard are always considered to be known - - if Sloc (E) <= Standard_Location then - return True; - - -- An entity that does not come from source is always considered - -- to be unknown, since it is an artifact of code expansion. - - elsif not Comes_From_Source (E) then - return False; - - -- In gnat internal mode, we consider all entities known - - elsif GNAT_Mode then - return True; - end if; - - -- Here we have an entity that is not from package Standard, and - -- which comes from Source. See if it comes from an internal file. - - Fname := Unit_File_Name (Get_Source_Unit (E)); - - -- Case of from internal file - - if Is_Internal_File_Name (Fname) then - - -- Private part entities in internal files are never considered - -- to be known to the writer of normal application code. - - if Is_Hidden (E) then - return False; - end if; - - -- Entities from System packages other than System and - -- System.Storage_Elements are not considered to be known. - -- System.Auxxxx files are also considered known to the user. - - -- Should refine this at some point to generally distinguish - -- between known and unknown internal files ??? - - Get_Name_String (Fname); - - return - Name_Len < 2 - or else - Name_Buffer (1 .. 2) /= "s-" - or else - Name_Buffer (3 .. 8) = "stoele" - or else - Name_Buffer (3 .. 5) = "aux"; - - -- If not an internal file, then entity is definitely known, - -- even if it is in a private part (the message generated will - -- note that it is in a private part) - - else - return True; - end if; - end Known_But_Invisible; - - ------------------- - -- Nvis_Messages -- - ------------------- - - procedure Nvis_Messages is - Comp_Unit : Node_Id; - Ent : Entity_Id; - Hidden : Boolean := False; - Item : Node_Id; - - begin - -- Ada 2005 (AI-262): Generate a precise error concerning the - -- Beaujolais effect that was previously detected - - if Nvis_Is_Private_Subprg then - - pragma Assert (Nkind (E2) = N_Defining_Identifier - and then Ekind (E2) = E_Function - and then Scope (E2) = Standard_Standard - and then Has_Private_With (E2)); - - -- Find the sloc corresponding to the private with'ed unit - - Comp_Unit := Cunit (Current_Sem_Unit); - Error_Msg_Sloc := No_Location; - - Item := First (Context_Items (Comp_Unit)); - while Present (Item) loop - if Nkind (Item) = N_With_Clause - and then Private_Present (Item) - and then Entity (Name (Item)) = E2 - then - Error_Msg_Sloc := Sloc (Item); - exit; - end if; - - Next (Item); - end loop; - - pragma Assert (Error_Msg_Sloc /= No_Location); - - Error_Msg_N ("(Ada 2005): hidden by private with clause #", N); - return; - end if; - - Undefined (Nvis => True); - - if Msg then - - -- First loop does hidden declarations - - Ent := Homonyms; - while Present (Ent) loop - if Is_Potentially_Use_Visible (Ent) then - if not Hidden then - Error_Msg_N ("multiple use clauses cause hiding!", N); - Hidden := True; - end if; - - Error_Msg_Sloc := Sloc (Ent); - Error_Msg_N ("hidden declaration#!", N); - end if; - - Ent := Homonym (Ent); - end loop; - - -- If we found hidden declarations, then that's enough, don't - -- bother looking for non-visible declarations as well. - - if Hidden then - return; - end if; - - -- Second loop does non-directly visible declarations - - Ent := Homonyms; - while Present (Ent) loop - if not Is_Potentially_Use_Visible (Ent) then - - -- Do not bother the user with unknown entities - - if not Known_But_Invisible (Ent) then - goto Continue; - end if; - - Error_Msg_Sloc := Sloc (Ent); - - -- Output message noting that there is a non-visible - -- declaration, distinguishing the private part case. - - if Is_Hidden (Ent) then - Error_Msg_N ("non-visible (private) declaration#!", N); - else - Error_Msg_N ("non-visible declaration#!", N); - - if Is_Compilation_Unit (Ent) - and then - Nkind (Parent (Parent (N))) = N_Use_Package_Clause - then - Error_Msg_Qual_Level := 99; - Error_Msg_NE ("\\missing `WITH &;`", N, Ent); - Error_Msg_Qual_Level := 0; - end if; - end if; - - -- Set entity and its containing package as referenced. We - -- can't be sure of this, but this seems a better choice - -- to avoid unused entity messages. - - if Comes_From_Source (Ent) then - Set_Referenced (Ent); - Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent))); - end if; - end if; - - <<Continue>> - Ent := Homonym (Ent); - end loop; - end if; - end Nvis_Messages; - - --------------- - -- Undefined -- - --------------- - - procedure Undefined (Nvis : Boolean) is - Emsg : Error_Msg_Id; - - begin - -- We should never find an undefined internal name. If we do, then - -- see if we have previous errors. If so, ignore on the grounds that - -- it is probably a cascaded message (e.g. a block label from a badly - -- formed block). If no previous errors, then we have a real internal - -- error of some kind so raise an exception. - - if Is_Internal_Name (Chars (N)) then - if Total_Errors_Detected /= 0 then - return; - else - raise Program_Error; - end if; - end if; - - -- A very specialized error check, if the undefined variable is - -- a case tag, and the case type is an enumeration type, check - -- for a possible misspelling, and if so, modify the identifier - - -- Named aggregate should also be handled similarly ??? - - if Nkind (N) = N_Identifier - and then Nkind (Parent (N)) = N_Case_Statement_Alternative - then - declare - Case_Stm : constant Node_Id := Parent (Parent (N)); - Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm)); - - Lit : Node_Id; - - begin - if Is_Enumeration_Type (Case_Typ) - and then not Is_Standard_Character_Type (Case_Typ) - then - Lit := First_Literal (Case_Typ); - Get_Name_String (Chars (Lit)); - - if Chars (Lit) /= Chars (N) - and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then - Error_Msg_Node_2 := Lit; - Error_Msg_N - ("& is undefined, assume misspelling of &", N); - Rewrite (N, New_Occurrence_Of (Lit, Sloc (N))); - return; - end if; - - Lit := Next_Literal (Lit); - end if; - end; - end if; - - -- Normal processing - - Set_Entity (N, Any_Id); - Set_Etype (N, Any_Type); - - -- We use the table Urefs to keep track of entities for which we - -- have issued errors for undefined references. Multiple errors - -- for a single name are normally suppressed, however we modify - -- the error message to alert the programmer to this effect. - - for J in Urefs.First .. Urefs.Last loop - if Chars (N) = Chars (Urefs.Table (J).Node) then - if Urefs.Table (J).Err /= No_Error_Msg - and then Sloc (N) /= Urefs.Table (J).Loc - then - Error_Msg_Node_1 := Urefs.Table (J).Node; - - if Urefs.Table (J).Nvis then - Change_Error_Text (Urefs.Table (J).Err, - "& is not visible (more references follow)"); - else - Change_Error_Text (Urefs.Table (J).Err, - "& is undefined (more references follow)"); - end if; - - Urefs.Table (J).Err := No_Error_Msg; - end if; - - -- Although we will set Msg False, and thus suppress the - -- message, we also set Error_Posted True, to avoid any - -- cascaded messages resulting from the undefined reference. - - Msg := False; - Set_Error_Posted (N, True); - return; - end if; - end loop; - - -- If entry not found, this is first undefined occurrence - - if Nvis then - Error_Msg_N ("& is not visible!", N); - Emsg := Get_Msg_Id; - - else - Error_Msg_N ("& is undefined!", N); - Emsg := Get_Msg_Id; - - -- A very bizarre special check, if the undefined identifier - -- is put or put_line, then add a special error message (since - -- this is a very common error for beginners to make). - - if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then - Error_Msg_N - ("\\possible missing `WITH Ada.Text_'I'O; " & - "USE Ada.Text_'I'O`!", N); - - -- Another special check if N is the prefix of a selected - -- component which is a known unit, add message complaining - -- about missing with for this unit. - - elsif Nkind (Parent (N)) = N_Selected_Component - and then N = Prefix (Parent (N)) - and then Is_Known_Unit (Parent (N)) - then - Error_Msg_Node_2 := Selector_Name (Parent (N)); - Error_Msg_N ("\\missing `WITH &.&;`", Prefix (Parent (N))); - end if; - - -- Now check for possible misspellings - - declare - E : Entity_Id; - Ematch : Entity_Id := Empty; - - Last_Name_Id : constant Name_Id := - Name_Id (Nat (First_Name_Id) + - Name_Entries_Count - 1); - - begin - for Nam in First_Name_Id .. Last_Name_Id loop - E := Get_Name_Entity_Id (Nam); - - if Present (E) - and then (Is_Immediately_Visible (E) - or else - Is_Potentially_Use_Visible (E)) - then - if Is_Bad_Spelling_Of (Chars (N), Nam) then - Ematch := E; - exit; - end if; - end if; - end loop; - - if Present (Ematch) then - Error_Msg_NE ("\possible misspelling of&", N, Ematch); - end if; - end; - end if; - - -- Make entry in undefined references table unless the full errors - -- switch is set, in which case by refraining from generating the - -- table entry, we guarantee that we get an error message for every - -- undefined reference. - - if not All_Errors_Mode then - Urefs.Append ( - (Node => N, - Err => Emsg, - Nvis => Nvis, - Loc => Sloc (N))); - end if; - - Msg := True; - end Undefined; - - -- Start of processing for Find_Direct_Name - - begin - -- If the entity pointer is already set, this is an internal node, or - -- a node that is analyzed more than once, after a tree modification. - -- In such a case there is no resolution to perform, just set the type. - - if Present (Entity (N)) then - if Is_Type (Entity (N)) then - Set_Etype (N, Entity (N)); - - else - declare - Entyp : constant Entity_Id := Etype (Entity (N)); - - begin - -- One special case here. If the Etype field is already set, - -- and references the packed array type corresponding to the - -- etype of the referenced entity, then leave it alone. This - -- happens for trees generated from Exp_Pakd, where expressions - -- can be deliberately "mis-typed" to the packed array type. - - if Is_Array_Type (Entyp) - and then Is_Packed (Entyp) - and then Present (Etype (N)) - and then Etype (N) = Packed_Array_Type (Entyp) - then - null; - - -- If not that special case, then just reset the Etype - - else - Set_Etype (N, Etype (Entity (N))); - end if; - end; - end if; - - return; - end if; - - -- Here if Entity pointer was not set, we need full visibility analysis - -- First we generate debugging output if the debug E flag is set. - - if Debug_Flag_E then - Write_Str ("Looking for "); - Write_Name (Chars (N)); - Write_Eol; - end if; - - Homonyms := Current_Entity (N); - Nvis_Entity := False; - - E := Homonyms; - while Present (E) loop - - -- If entity is immediately visible or potentially use visible, then - -- process the entity and we are done. - - if Is_Immediately_Visible (E) then - goto Immediately_Visible_Entity; - - elsif Is_Potentially_Use_Visible (E) then - goto Potentially_Use_Visible_Entity; - - -- Note if a known but invisible entity encountered - - elsif Known_But_Invisible (E) then - Nvis_Entity := True; - end if; - - -- Move to next entity in chain and continue search - - E := Homonym (E); - end loop; - - -- If no entries on homonym chain that were potentially visible, - -- and no entities reasonably considered as non-visible, then - -- we have a plain undefined reference, with no additional - -- explanation required! - - if not Nvis_Entity then - Undefined (Nvis => False); - - -- Otherwise there is at least one entry on the homonym chain that - -- is reasonably considered as being known and non-visible. - - else - Nvis_Messages; - end if; - - return; - - -- Processing for a potentially use visible entry found. We must search - -- the rest of the homonym chain for two reasons. First, if there is a - -- directly visible entry, then none of the potentially use-visible - -- entities are directly visible (RM 8.4(10)). Second, we need to check - -- for the case of multiple potentially use-visible entries hiding one - -- another and as a result being non-directly visible (RM 8.4(11)). - - <<Potentially_Use_Visible_Entity>> declare - Only_One_Visible : Boolean := True; - All_Overloadable : Boolean := Is_Overloadable (E); - - begin - E2 := Homonym (E); - while Present (E2) loop - if Is_Immediately_Visible (E2) then - - -- If the use-visible entity comes from the actual for a - -- formal package, it hides a directly visible entity from - -- outside the instance. - - if From_Actual_Package (E) - and then Scope_Depth (E2) < Scope_Depth (Inst) - then - goto Found; - else - E := E2; - goto Immediately_Visible_Entity; - end if; - - elsif Is_Potentially_Use_Visible (E2) then - Only_One_Visible := False; - All_Overloadable := All_Overloadable and Is_Overloadable (E2); - - -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect - -- that can occur in private_with clauses. Example: - - -- with A; - -- private with B; package A is - -- package C is function B return Integer; - -- use A; end A; - -- V1 : Integer := B; - -- private function B return Integer; - -- V2 : Integer := B; - -- end C; - - -- V1 resolves to A.B, but V2 resolves to library unit B - - elsif Ekind (E2) = E_Function - and then Scope (E2) = Standard_Standard - and then Has_Private_With (E2) - then - Only_One_Visible := False; - All_Overloadable := False; - Nvis_Is_Private_Subprg := True; - exit; - end if; - - E2 := Homonym (E2); - end loop; - - -- On falling through this loop, we have checked that there are no - -- immediately visible entities. Only_One_Visible is set if exactly - -- one potentially use visible entity exists. All_Overloadable is - -- set if all the potentially use visible entities are overloadable. - -- The condition for legality is that either there is one potentially - -- use visible entity, or if there is more than one, then all of them - -- are overloadable. - - if Only_One_Visible or All_Overloadable then - goto Found; - - -- If there is more than one potentially use-visible entity and at - -- least one of them non-overloadable, we have an error (RM 8.4(11). - -- Note that E points to the first such entity on the homonym list. - -- Special case: if one of the entities is declared in an actual - -- package, it was visible in the generic, and takes precedence over - -- other entities that are potentially use-visible. Same if it is - -- declared in a local instantiation of the current instance. - - else - if In_Instance then - - -- Find current instance - - Inst := Current_Scope; - while Present (Inst) - and then Inst /= Standard_Standard - loop - if Is_Generic_Instance (Inst) then - exit; - end if; - - Inst := Scope (Inst); - end loop; - - E2 := E; - while Present (E2) loop - if From_Actual_Package (E2) - or else - (Is_Generic_Instance (Scope (E2)) - and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst)) - then - E := E2; - goto Found; - end if; - - E2 := Homonym (E2); - end loop; - - Nvis_Messages; - return; - - elsif - Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit)) - then - -- A use-clause in the body of a system file creates conflict - -- with some entity in a user scope, while rtsfind is active. - -- Keep only the entity coming from another predefined unit. - - E2 := E; - while Present (E2) loop - if Is_Predefined_File_Name - (Unit_File_Name (Get_Source_Unit (Sloc (E2)))) - then - E := E2; - goto Found; - end if; - - E2 := Homonym (E2); - end loop; - - -- Entity must exist because predefined unit is correct - - raise Program_Error; - - else - Nvis_Messages; - return; - end if; - end if; - end; - - -- Come here with E set to the first immediately visible entity on - -- the homonym chain. This is the one we want unless there is another - -- immediately visible entity further on in the chain for an inner - -- scope (RM 8.3(8)). - - <<Immediately_Visible_Entity>> declare - Level : Int; - Scop : Entity_Id; - - begin - -- Find scope level of initial entity. When compiling through - -- Rtsfind, the previous context is not completely invisible, and - -- an outer entity may appear on the chain, whose scope is below - -- the entry for Standard that delimits the current scope stack. - -- Indicate that the level for this spurious entry is outside of - -- the current scope stack. - - Level := Scope_Stack.Last; - loop - Scop := Scope_Stack.Table (Level).Entity; - exit when Scop = Scope (E); - Level := Level - 1; - exit when Scop = Standard_Standard; - end loop; - - -- Now search remainder of homonym chain for more inner entry - -- If the entity is Standard itself, it has no scope, and we - -- compare it with the stack entry directly. - - E2 := Homonym (E); - while Present (E2) loop - if Is_Immediately_Visible (E2) then - - -- If a generic package contains a local declaration that - -- has the same name as the generic, there may be a visibility - -- conflict in an instance, where the local declaration must - -- also hide the name of the corresponding package renaming. - -- We check explicitly for a package declared by a renaming, - -- whose renamed entity is an instance that is on the scope - -- stack, and that contains a homonym in the same scope. Once - -- we have found it, we know that the package renaming is not - -- immediately visible, and that the identifier denotes the - -- other entity (and its homonyms if overloaded). - - if Scope (E) = Scope (E2) - and then Ekind (E) = E_Package - and then Present (Renamed_Object (E)) - and then Is_Generic_Instance (Renamed_Object (E)) - and then In_Open_Scopes (Renamed_Object (E)) - and then Comes_From_Source (N) - then - Set_Is_Immediately_Visible (E, False); - E := E2; - - else - for J in Level + 1 .. Scope_Stack.Last loop - if Scope_Stack.Table (J).Entity = Scope (E2) - or else Scope_Stack.Table (J).Entity = E2 - then - Level := J; - E := E2; - exit; - end if; - end loop; - end if; - end if; - - E2 := Homonym (E2); - end loop; - - -- At the end of that loop, E is the innermost immediately - -- visible entity, so we are all set. - end; - - -- Come here with entity found, and stored in E - - <<Found>> begin - - -- When distribution features are available (Get_PCS_Name /= - -- Name_No_DSA), a remote access-to-subprogram type is converted - -- into a record type holding whatever information is needed to - -- perform a remote call on an RCI subprogram. In that case we - -- rewrite any occurrence of the RAS type into the equivalent record - -- type here. 'Access attribute references and RAS dereferences are - -- then implemented using specific TSSs. However when distribution is - -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the - -- generation of these TSSs, and we must keep the RAS type in its - -- original access-to-subprogram form (since all calls through a - -- value of such type will be local anyway in the absence of a PCS). - - if Comes_From_Source (N) - and then Is_Remote_Access_To_Subprogram_Type (E) - and then Expander_Active - and then Get_PCS_Name /= Name_No_DSA - then - Rewrite (N, - New_Occurrence_Of (Equivalent_Type (E), Sloc (N))); - return; - end if; - - Set_Entity (N, E); - -- Why no Style_Check here??? - - if Is_Type (E) then - Set_Etype (N, E); - else - Set_Etype (N, Get_Full_View (Etype (E))); - end if; - - if Debug_Flag_E then - Write_Str (" found "); - Write_Entity_Info (E, " "); - end if; - - -- If the Ekind of the entity is Void, it means that all homonyms - -- are hidden from all visibility (RM 8.3(5,14-20)). However, this - -- test is skipped if the current scope is a record and the name is - -- a pragma argument expression (case of Atomic and Volatile pragmas - -- and possibly other similar pragmas added later, which are allowed - -- to reference components in the current record). - - if Ekind (E) = E_Void - and then - (not Is_Record_Type (Current_Scope) - or else Nkind (Parent (N)) /= N_Pragma_Argument_Association) - then - Premature_Usage (N); - - -- If the entity is overloadable, collect all interpretations of the - -- name for subsequent overload resolution. We optimize a bit here to - -- do this only if we have an overloadable entity that is not on its - -- own on the homonym chain. - - elsif Is_Overloadable (E) - and then (Present (Homonym (E)) or else Current_Entity (N) /= E) - then - Collect_Interps (N); - - -- If no homonyms were visible, the entity is unambiguous - - if not Is_Overloaded (N) then - if not Is_Actual_Parameter then - Generate_Reference (E, N); - end if; - end if; - - -- Case of non-overloadable entity, set the entity providing that - -- we do not have the case of a discriminant reference within a - -- default expression. Such references are replaced with the - -- corresponding discriminal, which is the formal corresponding to - -- to the discriminant in the initialization procedure. - - else - -- Entity is unambiguous, indicate that it is referenced here - - -- For a renaming of an object, always generate simple reference, - -- we don't try to keep track of assignments in this case. - - if Is_Object (E) and then Present (Renamed_Object (E)) then - Generate_Reference (E, N); - - -- If the renamed entity is a private protected component, - -- reference the original component as well. This needs to be - -- done because the private renamings are installed before any - -- analysis has occurred. Reference to a private component will - -- resolve to the renaming and the original component will be - -- left unreferenced, hence the following. - - if Is_Prival (E) then - Generate_Reference (Prival_Link (E), N); - end if; - - -- One odd case is that we do not want to set the Referenced flag - -- if the entity is a label, and the identifier is the label in - -- the source, since this is not a reference from the point of - -- view of the user. - - elsif Nkind (Parent (N)) = N_Label then - declare - R : constant Boolean := Referenced (E); - - begin - -- Generate reference unless this is an actual parameter - -- (see comment below) - - if Is_Actual_Parameter then - Generate_Reference (E, N); - Set_Referenced (E, R); - end if; - end; - - -- Normal case, not a label: generate reference - - -- ??? It is too early to generate a reference here even if - -- the entity is unambiguous, because the tree is not - -- sufficiently typed at this point for Generate_Reference to - -- determine whether this reference modifies the denoted object - -- (because implicit dereferences cannot be identified prior to - -- full type resolution). - -- - -- The Is_Actual_Parameter routine takes care of one of these - -- cases but there are others probably ??? - - else - if not Is_Actual_Parameter then - Generate_Reference (E, N); - end if; - - Check_Nested_Access (E); - end if; - - -- Set Entity, with style check if need be. For a discriminant - -- reference, replace by the corresponding discriminal, i.e. the - -- parameter of the initialization procedure that corresponds to - -- the discriminant. If this replacement is being performed, there - -- is no style check to perform. - - -- This replacement must not be done if we are currently - -- processing a generic spec or body, because the discriminal - -- has not been not generated in this case. - - -- The replacement is also skipped if we are in special - -- spec-expression mode. Why is this skipped in this case ??? - - if not In_Spec_Expression - or else Ekind (E) /= E_Discriminant - or else Inside_A_Generic - then - Set_Entity_With_Style_Check (N, E); - - -- The replacement is not done either for a task discriminant that - -- appears in a default expression of an entry parameter. See - -- Expand_Discriminant in exp_ch2 for details on their handling. - - elsif Is_Concurrent_Type (Scope (E)) then - declare - P : Node_Id; - - begin - P := Parent (N); - while Present (P) - and then not Nkind_In (P, N_Parameter_Specification, - N_Component_Declaration) - loop - P := Parent (P); - end loop; - - if Present (P) - and then Nkind (P) = N_Parameter_Specification - then - null; - else - Set_Entity (N, Discriminal (E)); - end if; - end; - - -- Otherwise, this is a discriminant in a context in which - -- it is a reference to the corresponding parameter of the - -- init proc for the enclosing type. - - else - Set_Entity (N, Discriminal (E)); - end if; - end if; - end; - end Find_Direct_Name; - - ------------------------ - -- Find_Expanded_Name -- - ------------------------ - - -- This routine searches the homonym chain of the entity until it finds - -- an entity declared in the scope denoted by the prefix. If the entity - -- is private, it may nevertheless be immediately visible, if we are in - -- the scope of its declaration. - - procedure Find_Expanded_Name (N : Node_Id) is - Selector : constant Node_Id := Selector_Name (N); - Candidate : Entity_Id := Empty; - P_Name : Entity_Id; - O_Name : Entity_Id; - Id : Entity_Id; - - begin - P_Name := Entity (Prefix (N)); - O_Name := P_Name; - - -- If the prefix is a renamed package, look for the entity in the - -- original package. - - if Ekind (P_Name) = E_Package - and then Present (Renamed_Object (P_Name)) - then - P_Name := Renamed_Object (P_Name); - - -- Rewrite node with entity field pointing to renamed object - - Rewrite (Prefix (N), New_Copy (Prefix (N))); - Set_Entity (Prefix (N), P_Name); - - -- If the prefix is an object of a concurrent type, look for - -- the entity in the associated task or protected type. - - elsif Is_Concurrent_Type (Etype (P_Name)) then - P_Name := Etype (P_Name); - end if; - - Id := Current_Entity (Selector); - - declare - Is_New_Candidate : Boolean; - - begin - while Present (Id) loop - if Scope (Id) = P_Name then - Candidate := Id; - Is_New_Candidate := True; - - -- Ada 2005 (AI-217): Handle shadow entities associated with types - -- declared in limited-withed nested packages. We don't need to - -- handle E_Incomplete_Subtype entities because the entities in - -- the limited view are always E_Incomplete_Type entities (see - -- Build_Limited_Views). Regarding the expression used to evaluate - -- the scope, it is important to note that the limited view also - -- has shadow entities associated nested packages. For this reason - -- the correct scope of the entity is the scope of the real entity - -- The non-limited view may itself be incomplete, in which case - -- get the full view if available. - - elsif From_With_Type (Id) - and then Is_Type (Id) - and then Ekind (Id) = E_Incomplete_Type - and then Present (Non_Limited_View (Id)) - and then Scope (Non_Limited_View (Id)) = P_Name - then - Candidate := Get_Full_View (Non_Limited_View (Id)); - Is_New_Candidate := True; - - else - Is_New_Candidate := False; - end if; - - if Is_New_Candidate then - if Is_Child_Unit (Id) then - exit when Is_Visible_Child_Unit (Id) - or else Is_Immediately_Visible (Id); - - else - exit when not Is_Hidden (Id) - or else Is_Immediately_Visible (Id); - end if; - end if; - - Id := Homonym (Id); - end loop; - end; - - if No (Id) - and then (Ekind (P_Name) = E_Procedure - or else - Ekind (P_Name) = E_Function) - and then Is_Generic_Instance (P_Name) - then - -- Expanded name denotes entity in (instance of) generic subprogram. - -- The entity may be in the subprogram instance, or may denote one of - -- the formals, which is declared in the enclosing wrapper package. - - P_Name := Scope (P_Name); - - Id := Current_Entity (Selector); - while Present (Id) loop - exit when Scope (Id) = P_Name; - Id := Homonym (Id); - end loop; - end if; - - if No (Id) or else Chars (Id) /= Chars (Selector) then - Set_Etype (N, Any_Type); - - -- If we are looking for an entity defined in System, try to find it - -- in the child package that may have been provided as an extension - -- to System. The Extend_System pragma will have supplied the name of - -- the extension, which may have to be loaded. - - if Chars (P_Name) = Name_System - and then Scope (P_Name) = Standard_Standard - and then Present (System_Extend_Unit) - and then Present_System_Aux (N) - then - Set_Entity (Prefix (N), System_Aux_Id); - Find_Expanded_Name (N); - return; - - elsif Nkind (Selector) = N_Operator_Symbol - and then Has_Implicit_Operator (N) - then - -- There is an implicit instance of the predefined operator in - -- the given scope. The operator entity is defined in Standard. - -- Has_Implicit_Operator makes the node into an Expanded_Name. - - return; - - elsif Nkind (Selector) = N_Character_Literal - and then Has_Implicit_Character_Literal (N) - then - -- If there is no literal defined in the scope denoted by the - -- prefix, the literal may belong to (a type derived from) - -- Standard_Character, for which we have no explicit literals. - - return; - - else - -- If the prefix is a single concurrent object, use its name in - -- the error message, rather than that of the anonymous type. - - if Is_Concurrent_Type (P_Name) - and then Is_Internal_Name (Chars (P_Name)) - then - Error_Msg_Node_2 := Entity (Prefix (N)); - else - Error_Msg_Node_2 := P_Name; - end if; - - if P_Name = System_Aux_Id then - P_Name := Scope (P_Name); - Set_Entity (Prefix (N), P_Name); - end if; - - if Present (Candidate) then - - -- If we know that the unit is a child unit we can give a more - -- accurate error message. - - if Is_Child_Unit (Candidate) then - - -- If the candidate is a private child unit and we are in - -- the visible part of a public unit, specialize the error - -- message. There might be a private with_clause for it, - -- but it is not currently active. - - if Is_Private_Descendant (Candidate) - and then Ekind (Current_Scope) = E_Package - and then not In_Private_Part (Current_Scope) - and then not Is_Private_Descendant (Current_Scope) - then - Error_Msg_N ("private child unit& is not visible here", - Selector); - - -- Normal case where we have a missing with for a child unit - - else - Error_Msg_Qual_Level := 99; - Error_Msg_NE ("missing `WITH &;`", Selector, Candidate); - Error_Msg_Qual_Level := 0; - end if; - - -- Here we don't know that this is a child unit - - else - Error_Msg_NE ("& is not a visible entity of&", N, Selector); - end if; - - else - -- Within the instantiation of a child unit, the prefix may - -- denote the parent instance, but the selector has the name - -- of the original child. Find whether we are within the - -- corresponding instance, and get the proper entity, which - -- can only be an enclosing scope. - - if O_Name /= P_Name - and then In_Open_Scopes (P_Name) - and then Is_Generic_Instance (P_Name) - then - declare - S : Entity_Id := Current_Scope; - P : Entity_Id; - - begin - for J in reverse 0 .. Scope_Stack.Last loop - S := Scope_Stack.Table (J).Entity; - - exit when S = Standard_Standard; - - if Ekind (S) = E_Function - or else Ekind (S) = E_Package - or else Ekind (S) = E_Procedure - then - P := Generic_Parent (Specification - (Unit_Declaration_Node (S))); - - if Present (P) - and then Chars (Scope (P)) = Chars (O_Name) - and then Chars (P) = Chars (Selector) - then - Id := S; - goto Found; - end if; - end if; - - end loop; - end; - end if; - - -- If this is a selection from Ada, System or Interfaces, then - -- we assume a missing with for the corresponding package. - - if Is_Known_Unit (N) then - if not Error_Posted (N) then - Error_Msg_Node_2 := Selector; - Error_Msg_N ("missing `WITH &.&;`", Prefix (N)); - end if; - - -- If this is a selection from a dummy package, then suppress - -- the error message, of course the entity is missing if the - -- package is missing! - - elsif Sloc (Error_Msg_Node_2) = No_Location then - null; - - -- Here we have the case of an undefined component - - else - Error_Msg_NE ("& not declared in&", N, Selector); - - -- Check for misspelling of some entity in prefix - - Id := First_Entity (P_Name); - while Present (Id) loop - if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector)) - and then not Is_Internal_Name (Chars (Id)) - then - Error_Msg_NE - ("possible misspelling of&", Selector, Id); - exit; - end if; - - Next_Entity (Id); - end loop; - - -- Specialize the message if this may be an instantiation - -- of a child unit that was not mentioned in the context. - - if Nkind (Parent (N)) = N_Package_Instantiation - and then Is_Generic_Instance (Entity (Prefix (N))) - and then Is_Compilation_Unit - (Generic_Parent (Parent (Entity (Prefix (N))))) - then - Error_Msg_Node_2 := Selector; - Error_Msg_N ("\missing `WITH &.&;`", Prefix (N)); - end if; - end if; - end if; - - Id := Any_Id; - end if; - end if; - - <<Found>> - if Comes_From_Source (N) - and then Is_Remote_Access_To_Subprogram_Type (Id) - and then Present (Equivalent_Type (Id)) - then - -- If we are not actually generating distribution code (i.e. the - -- current PCS is the dummy non-distributed version), then the - -- Equivalent_Type will be missing, and Id should be treated as - -- a regular access-to-subprogram type. - - Id := Equivalent_Type (Id); - Set_Chars (Selector, Chars (Id)); - end if; - - -- Ada 2005 (AI-50217): Check usage of entities in limited withed units - - if Ekind (P_Name) = E_Package - and then From_With_Type (P_Name) - then - if From_With_Type (Id) - or else Is_Type (Id) - or else Ekind (Id) = E_Package - then - null; - else - Error_Msg_N - ("limited withed package can only be used to access " - & "incomplete types", - N); - end if; - end if; - - if Is_Task_Type (P_Name) - and then ((Ekind (Id) = E_Entry - and then Nkind (Parent (N)) /= N_Attribute_Reference) - or else - (Ekind (Id) = E_Entry_Family - and then - Nkind (Parent (Parent (N))) /= N_Attribute_Reference)) - then - -- It is an entry call after all, either to the current task (which - -- will deadlock) or to an enclosing task. - - Analyze_Selected_Component (N); - return; - end if; - - Change_Selected_Component_To_Expanded_Name (N); - - -- Do style check and generate reference, but skip both steps if this - -- entity has homonyms, since we may not have the right homonym set yet. - -- The proper homonym will be set during the resolve phase. - - if Has_Homonym (Id) then - Set_Entity (N, Id); - else - Set_Entity_With_Style_Check (N, Id); - Generate_Reference (Id, N); - end if; - - if Is_Type (Id) then - Set_Etype (N, Id); - else - Set_Etype (N, Get_Full_View (Etype (Id))); - end if; - - -- If the Ekind of the entity is Void, it means that all homonyms are - -- hidden from all visibility (RM 8.3(5,14-20)). - - if Ekind (Id) = E_Void then - Premature_Usage (N); - - elsif Is_Overloadable (Id) - and then Present (Homonym (Id)) - then - declare - H : Entity_Id := Homonym (Id); - - begin - while Present (H) loop - if Scope (H) = Scope (Id) - and then - (not Is_Hidden (H) - or else Is_Immediately_Visible (H)) - then - Collect_Interps (N); - exit; - end if; - - H := Homonym (H); - end loop; - - -- If an extension of System is present, collect possible explicit - -- overloadings declared in the extension. - - if Chars (P_Name) = Name_System - and then Scope (P_Name) = Standard_Standard - and then Present (System_Extend_Unit) - and then Present_System_Aux (N) - then - H := Current_Entity (Id); - - while Present (H) loop - if Scope (H) = System_Aux_Id then - Add_One_Interp (N, H, Etype (H)); - end if; - - H := Homonym (H); - end loop; - end if; - end; - end if; - - if Nkind (Selector_Name (N)) = N_Operator_Symbol - and then Scope (Id) /= Standard_Standard - then - -- In addition to user-defined operators in the given scope, there - -- may be an implicit instance of the predefined operator. The - -- operator (defined in Standard) is found in Has_Implicit_Operator, - -- and added to the interpretations. Procedure Add_One_Interp will - -- determine which hides which. - - if Has_Implicit_Operator (N) then - null; - end if; - end if; - end Find_Expanded_Name; - - ------------------------- - -- Find_Renamed_Entity -- - ------------------------- - - function Find_Renamed_Entity - (N : Node_Id; - Nam : Node_Id; - New_S : Entity_Id; - Is_Actual : Boolean := False) return Entity_Id - is - Ind : Interp_Index; - I1 : Interp_Index := 0; -- Suppress junk warnings - It : Interp; - It1 : Interp; - Old_S : Entity_Id; - Inst : Entity_Id; - - function Enclosing_Instance return Entity_Id; - -- If the renaming determines the entity for the default of a formal - -- subprogram nested within another instance, choose the innermost - -- candidate. This is because if the formal has a box, and we are within - -- an enclosing instance where some candidate interpretations are local - -- to this enclosing instance, we know that the default was properly - -- resolved when analyzing the generic, so we prefer the local - -- candidates to those that are external. This is not always the case - -- but is a reasonable heuristic on the use of nested generics. The - -- proper solution requires a full renaming model. - - function Is_Visible_Operation (Op : Entity_Id) return Boolean; - -- If the renamed entity is an implicit operator, check whether it is - -- visible because its operand type is properly visible. This check - -- applies to explicit renamed entities that appear in the source in a - -- renaming declaration or a formal subprogram instance, but not to - -- default generic actuals with a name. - - function Report_Overload return Entity_Id; - -- List possible interpretations, and specialize message in the - -- case of a generic actual. - - function Within (Inner, Outer : Entity_Id) return Boolean; - -- Determine whether a candidate subprogram is defined within the - -- enclosing instance. If yes, it has precedence over outer candidates. - - ------------------------ - -- Enclosing_Instance -- - ------------------------ - - function Enclosing_Instance return Entity_Id is - S : Entity_Id; - - begin - if not Is_Generic_Instance (Current_Scope) - and then not Is_Actual - then - return Empty; - end if; - - S := Scope (Current_Scope); - while S /= Standard_Standard loop - if Is_Generic_Instance (S) then - return S; - end if; - - S := Scope (S); - end loop; - - return Empty; - end Enclosing_Instance; - - -------------------------- - -- Is_Visible_Operation -- - -------------------------- - - function Is_Visible_Operation (Op : Entity_Id) return Boolean is - Scop : Entity_Id; - Typ : Entity_Id; - Btyp : Entity_Id; - - begin - if Ekind (Op) /= E_Operator - or else Scope (Op) /= Standard_Standard - or else (In_Instance - and then - (not Is_Actual - or else Present (Enclosing_Instance))) - then - return True; - - else - -- For a fixed point type operator, check the resulting type, - -- because it may be a mixed mode integer * fixed operation. - - if Present (Next_Formal (First_Formal (New_S))) - and then Is_Fixed_Point_Type (Etype (New_S)) - then - Typ := Etype (New_S); - else - Typ := Etype (First_Formal (New_S)); - end if; - - Btyp := Base_Type (Typ); - - if Nkind (Nam) /= N_Expanded_Name then - return (In_Open_Scopes (Scope (Btyp)) - or else Is_Potentially_Use_Visible (Btyp) - or else In_Use (Btyp) - or else In_Use (Scope (Btyp))); - - else - Scop := Entity (Prefix (Nam)); - - if Ekind (Scop) = E_Package - and then Present (Renamed_Object (Scop)) - then - Scop := Renamed_Object (Scop); - end if; - - -- Operator is visible if prefix of expanded name denotes - -- scope of type, or else type is defined in System_Aux - -- and the prefix denotes System. - - return Scope (Btyp) = Scop - or else (Scope (Btyp) = System_Aux_Id - and then Scope (Scope (Btyp)) = Scop); - end if; - end if; - end Is_Visible_Operation; - - ------------ - -- Within -- - ------------ - - function Within (Inner, Outer : Entity_Id) return Boolean is - Sc : Entity_Id; - - begin - Sc := Scope (Inner); - while Sc /= Standard_Standard loop - if Sc = Outer then - return True; - else - Sc := Scope (Sc); - end if; - end loop; - - return False; - end Within; - - --------------------- - -- Report_Overload -- - --------------------- - - function Report_Overload return Entity_Id is - begin - if Is_Actual then - Error_Msg_NE - ("ambiguous actual subprogram&, " & - "possible interpretations:", N, Nam); - else - Error_Msg_N - ("ambiguous subprogram, " & - "possible interpretations:", N); - end if; - - List_Interps (Nam, N); - return Old_S; - end Report_Overload; - - -- Start of processing for Find_Renamed_Entry - - begin - Old_S := Any_Id; - Candidate_Renaming := Empty; - - if not Is_Overloaded (Nam) then - if Entity_Matches_Spec (Entity (Nam), New_S) - and then Is_Visible_Operation (Entity (Nam)) - then - Old_S := Entity (Nam); - - elsif - Present (First_Formal (Entity (Nam))) - and then Present (First_Formal (New_S)) - and then (Base_Type (Etype (First_Formal (Entity (Nam)))) - = Base_Type (Etype (First_Formal (New_S)))) - then - Candidate_Renaming := Entity (Nam); - end if; - - else - Get_First_Interp (Nam, Ind, It); - while Present (It.Nam) loop - if Entity_Matches_Spec (It.Nam, New_S) - and then Is_Visible_Operation (It.Nam) - then - if Old_S /= Any_Id then - - -- Note: The call to Disambiguate only happens if a - -- previous interpretation was found, in which case I1 - -- has received a value. - - It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S)); - - if It1 = No_Interp then - Inst := Enclosing_Instance; - - if Present (Inst) then - if Within (It.Nam, Inst) then - return (It.Nam); - elsif Within (Old_S, Inst) then - return (Old_S); - else - return Report_Overload; - end if; - - else - return Report_Overload; - end if; - - else - Old_S := It1.Nam; - exit; - end if; - - else - I1 := Ind; - Old_S := It.Nam; - end if; - - elsif - Present (First_Formal (It.Nam)) - and then Present (First_Formal (New_S)) - and then (Base_Type (Etype (First_Formal (It.Nam))) - = Base_Type (Etype (First_Formal (New_S)))) - then - Candidate_Renaming := It.Nam; - end if; - - Get_Next_Interp (Ind, It); - end loop; - - Set_Entity (Nam, Old_S); - Set_Is_Overloaded (Nam, False); - end if; - - return Old_S; - end Find_Renamed_Entity; - - ----------------------------- - -- Find_Selected_Component -- - ----------------------------- - - procedure Find_Selected_Component (N : Node_Id) is - P : constant Node_Id := Prefix (N); - - P_Name : Entity_Id; - -- Entity denoted by prefix - - P_Type : Entity_Id; - -- and its type - - Nam : Node_Id; - - begin - Analyze (P); - - if Nkind (P) = N_Error then - return; - - -- If the selector already has an entity, the node has been constructed - -- in the course of expansion, and is known to be valid. Do not verify - -- that it is defined for the type (it may be a private component used - -- in the expansion of record equality). - - elsif Present (Entity (Selector_Name (N))) then - if No (Etype (N)) - or else Etype (N) = Any_Type - then - declare - Sel_Name : constant Node_Id := Selector_Name (N); - Selector : constant Entity_Id := Entity (Sel_Name); - C_Etype : Node_Id; - - begin - Set_Etype (Sel_Name, Etype (Selector)); - - if not Is_Entity_Name (P) then - Resolve (P); - end if; - - -- Build an actual subtype except for the first parameter - -- of an init proc, where this actual subtype is by - -- definition incorrect, since the object is uninitialized - -- (and does not even have defined discriminants etc.) - - if Is_Entity_Name (P) - and then Ekind (Entity (P)) = E_Function - then - Nam := New_Copy (P); - - if Is_Overloaded (P) then - Save_Interps (P, Nam); - end if; - - Rewrite (P, - Make_Function_Call (Sloc (P), Name => Nam)); - Analyze_Call (P); - Analyze_Selected_Component (N); - return; - - elsif Ekind (Selector) = E_Component - and then (not Is_Entity_Name (P) - or else Chars (Entity (P)) /= Name_uInit) - then - C_Etype := - Build_Actual_Subtype_Of_Component ( - Etype (Selector), N); - else - C_Etype := Empty; - end if; - - if No (C_Etype) then - C_Etype := Etype (Selector); - else - Insert_Action (N, C_Etype); - C_Etype := Defining_Identifier (C_Etype); - end if; - - Set_Etype (N, C_Etype); - end; - - -- If this is the name of an entry or protected operation, and - -- the prefix is an access type, insert an explicit dereference, - -- so that entry calls are treated uniformly. - - if Is_Access_Type (Etype (P)) - and then Is_Concurrent_Type (Designated_Type (Etype (P))) - then - declare - New_P : constant Node_Id := - Make_Explicit_Dereference (Sloc (P), - Prefix => Relocate_Node (P)); - begin - Rewrite (P, New_P); - Set_Etype (P, Designated_Type (Etype (Prefix (P)))); - end; - end if; - - -- If the selected component appears within a default expression - -- and it has an actual subtype, the pre-analysis has not yet - -- completed its analysis, because Insert_Actions is disabled in - -- that context. Within the init proc of the enclosing type we - -- must complete this analysis, if an actual subtype was created. - - elsif Inside_Init_Proc then - declare - Typ : constant Entity_Id := Etype (N); - Decl : constant Node_Id := Declaration_Node (Typ); - begin - if Nkind (Decl) = N_Subtype_Declaration - and then not Analyzed (Decl) - and then Is_List_Member (Decl) - and then No (Parent (Decl)) - then - Remove (Decl); - Insert_Action (N, Decl); - end if; - end; - end if; - - return; - - elsif Is_Entity_Name (P) then - P_Name := Entity (P); - - -- The prefix may denote an enclosing type which is the completion - -- of an incomplete type declaration. - - if Is_Type (P_Name) then - Set_Entity (P, Get_Full_View (P_Name)); - Set_Etype (P, Entity (P)); - P_Name := Entity (P); - end if; - - P_Type := Base_Type (Etype (P)); - - if Debug_Flag_E then - Write_Str ("Found prefix type to be "); - Write_Entity_Info (P_Type, " "); Write_Eol; - end if; - - -- First check for components of a record object (not the - -- result of a call, which is handled below). - - if Is_Appropriate_For_Record (P_Type) - and then not Is_Overloadable (P_Name) - and then not Is_Type (P_Name) - then - -- Selected component of record. Type checking will validate - -- name of selector. - -- ??? could we rewrite an implicit dereference into an explicit - -- one here? - - Analyze_Selected_Component (N); - - elsif Is_Appropriate_For_Entry_Prefix (P_Type) - and then not In_Open_Scopes (P_Name) - and then (not Is_Concurrent_Type (Etype (P_Name)) - or else not In_Open_Scopes (Etype (P_Name))) - then - -- Call to protected operation or entry. Type checking is - -- needed on the prefix. - - Analyze_Selected_Component (N); - - elsif (In_Open_Scopes (P_Name) - and then Ekind (P_Name) /= E_Void - and then not Is_Overloadable (P_Name)) - or else (Is_Concurrent_Type (Etype (P_Name)) - and then In_Open_Scopes (Etype (P_Name))) - then - -- Prefix denotes an enclosing loop, block, or task, i.e. an - -- enclosing construct that is not a subprogram or accept. - - Find_Expanded_Name (N); - - elsif Ekind (P_Name) = E_Package then - Find_Expanded_Name (N); - - elsif Is_Overloadable (P_Name) then - - -- The subprogram may be a renaming (of an enclosing scope) as - -- in the case of the name of the generic within an instantiation. - - if (Ekind (P_Name) = E_Procedure - or else Ekind (P_Name) = E_Function) - and then Present (Alias (P_Name)) - and then Is_Generic_Instance (Alias (P_Name)) - then - P_Name := Alias (P_Name); - end if; - - if Is_Overloaded (P) then - - -- The prefix must resolve to a unique enclosing construct - - declare - Found : Boolean := False; - Ind : Interp_Index; - It : Interp; - - begin - Get_First_Interp (P, Ind, It); - while Present (It.Nam) loop - if In_Open_Scopes (It.Nam) then - if Found then - Error_Msg_N ( - "prefix must be unique enclosing scope", N); - Set_Entity (N, Any_Id); - Set_Etype (N, Any_Type); - return; - - else - Found := True; - P_Name := It.Nam; - end if; - end if; - - Get_Next_Interp (Ind, It); - end loop; - end; - end if; - - if In_Open_Scopes (P_Name) then - Set_Entity (P, P_Name); - Set_Is_Overloaded (P, False); - Find_Expanded_Name (N); - - else - -- If no interpretation as an expanded name is possible, it - -- must be a selected component of a record returned by a - -- function call. Reformat prefix as a function call, the rest - -- is done by type resolution. If the prefix is procedure or - -- entry, as is P.X; this is an error. - - if Ekind (P_Name) /= E_Function - and then (not Is_Overloaded (P) - or else - Nkind (Parent (N)) = N_Procedure_Call_Statement) - then - -- Prefix may mention a package that is hidden by a local - -- declaration: let the user know. Scan the full homonym - -- chain, the candidate package may be anywhere on it. - - if Present (Homonym (Current_Entity (P_Name))) then - - P_Name := Current_Entity (P_Name); - - while Present (P_Name) loop - exit when Ekind (P_Name) = E_Package; - P_Name := Homonym (P_Name); - end loop; - - if Present (P_Name) then - Error_Msg_Sloc := Sloc (Entity (Prefix (N))); - - Error_Msg_NE - ("package& is hidden by declaration#", - N, P_Name); - - Set_Entity (Prefix (N), P_Name); - Find_Expanded_Name (N); - return; - else - P_Name := Entity (Prefix (N)); - end if; - end if; - - Error_Msg_NE - ("invalid prefix in selected component&", N, P_Name); - Change_Selected_Component_To_Expanded_Name (N); - Set_Entity (N, Any_Id); - Set_Etype (N, Any_Type); - - else - Nam := New_Copy (P); - Save_Interps (P, Nam); - Rewrite (P, - Make_Function_Call (Sloc (P), Name => Nam)); - Analyze_Call (P); - Analyze_Selected_Component (N); - end if; - end if; - - -- Remaining cases generate various error messages - - else - -- Format node as expanded name, to avoid cascaded errors - - Change_Selected_Component_To_Expanded_Name (N); - Set_Entity (N, Any_Id); - Set_Etype (N, Any_Type); - - -- Issue error message, but avoid this if error issued already. - -- Use identifier of prefix if one is available. - - if P_Name = Any_Id then - null; - - elsif Ekind (P_Name) = E_Void then - Premature_Usage (P); - - elsif Nkind (P) /= N_Attribute_Reference then - Error_Msg_N ( - "invalid prefix in selected component&", P); - - if Is_Access_Type (P_Type) - and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type - then - Error_Msg_N - ("\dereference must not be of an incomplete type " & - "(RM 3.10.1)", P); - end if; - - else - Error_Msg_N ( - "invalid prefix in selected component", P); - end if; - end if; - - else - -- If prefix is not the name of an entity, it must be an expression, - -- whose type is appropriate for a record. This is determined by - -- type resolution. - - Analyze_Selected_Component (N); - end if; - end Find_Selected_Component; - - --------------- - -- Find_Type -- - --------------- - - procedure Find_Type (N : Node_Id) is - C : Entity_Id; - Typ : Entity_Id; - T : Entity_Id; - T_Name : Entity_Id; - - begin - if N = Error then - return; - - elsif Nkind (N) = N_Attribute_Reference then - - -- Class attribute. This is not valid in Ada 83 mode, but we do not - -- need to enforce that at this point, since the declaration of the - -- tagged type in the prefix would have been flagged already. - - if Attribute_Name (N) = Name_Class then - Check_Restriction (No_Dispatch, N); - Find_Type (Prefix (N)); - - -- Propagate error from bad prefix - - if Etype (Prefix (N)) = Any_Type then - Set_Entity (N, Any_Type); - Set_Etype (N, Any_Type); - return; - end if; - - T := Base_Type (Entity (Prefix (N))); - - -- Case where type is not known to be tagged. Its appearance in - -- the prefix of the 'Class attribute indicates that the full view - -- will be tagged. - - if not Is_Tagged_Type (T) then - if Ekind (T) = E_Incomplete_Type then - - -- It is legal to denote the class type of an incomplete - -- type. The full type will have to be tagged, of course. - -- In Ada 2005 this usage is declared obsolescent, so we - -- warn accordingly. - - -- ??? This test is temporarily disabled (always False) - -- because it causes an unwanted warning on GNAT sources - -- (built with -gnatg, which includes Warn_On_Obsolescent_ - -- Feature). Once this issue is cleared in the sources, it - -- can be enabled. - - if not Is_Tagged_Type (T) - and then Ada_Version >= Ada_05 - and then Warn_On_Obsolescent_Feature - and then False - then - Error_Msg_N - ("applying 'Class to an untagged incomplete type" - & " is an obsolescent feature (RM J.11)", N); - end if; - - Set_Is_Tagged_Type (T); - Set_Primitive_Operations (T, New_Elmt_List); - Make_Class_Wide_Type (T); - Set_Entity (N, Class_Wide_Type (T)); - Set_Etype (N, Class_Wide_Type (T)); - - elsif Ekind (T) = E_Private_Type - and then not Is_Generic_Type (T) - and then In_Private_Part (Scope (T)) - then - -- The Class attribute can be applied to an untagged private - -- type fulfilled by a tagged type prior to the full type - -- declaration (but only within the parent package's private - -- part). Create the class-wide type now and check that the - -- full type is tagged later during its analysis. Note that - -- we do not mark the private type as tagged, unlike the - -- case of incomplete types, because the type must still - -- appear untagged to outside units. - - if No (Class_Wide_Type (T)) then - Make_Class_Wide_Type (T); - end if; - - Set_Entity (N, Class_Wide_Type (T)); - Set_Etype (N, Class_Wide_Type (T)); - - else - -- Should we introduce a type Any_Tagged and use Wrong_Type - -- here, it would be a bit more consistent??? - - Error_Msg_NE - ("tagged type required, found}", - Prefix (N), First_Subtype (T)); - Set_Entity (N, Any_Type); - return; - end if; - - -- Case of tagged type - - else - if Is_Concurrent_Type (T) then - if No (Corresponding_Record_Type (Entity (Prefix (N)))) then - - -- Previous error. Use current type, which at least - -- provides some operations. - - C := Entity (Prefix (N)); - - else - C := Class_Wide_Type - (Corresponding_Record_Type (Entity (Prefix (N)))); - end if; - - else - C := Class_Wide_Type (Entity (Prefix (N))); - end if; - - Set_Entity_With_Style_Check (N, C); - Generate_Reference (C, N); - Set_Etype (N, C); - end if; - - -- Base attribute, not allowed in Ada 83 - - elsif Attribute_Name (N) = Name_Base then - if Ada_Version = Ada_83 and then Comes_From_Source (N) then - Error_Msg_N - ("(Ada 83) Base attribute not allowed in subtype mark", N); - - else - Find_Type (Prefix (N)); - Typ := Entity (Prefix (N)); - - if Ada_Version >= Ada_95 - and then not Is_Scalar_Type (Typ) - and then not Is_Generic_Type (Typ) - then - Error_Msg_N - ("prefix of Base attribute must be scalar type", - Prefix (N)); - - elsif Sloc (Typ) = Standard_Location - and then Base_Type (Typ) = Typ - and then Warn_On_Redundant_Constructs - then - Error_Msg_NE - ("?redundant attribute, & is its own base type", N, Typ); - end if; - - T := Base_Type (Typ); - - -- Rewrite attribute reference with type itself (see similar - -- processing in Analyze_Attribute, case Base). Preserve - -- prefix if present, for other legality checks. - - if Nkind (Prefix (N)) = N_Expanded_Name then - Rewrite (N, - Make_Expanded_Name (Sloc (N), - Chars => Chars (T), - Prefix => New_Copy (Prefix (Prefix (N))), - Selector_Name => New_Reference_To (T, Sloc (N)))); - - else - Rewrite (N, New_Reference_To (T, Sloc (N))); - end if; - - Set_Entity (N, T); - Set_Etype (N, T); - end if; - - elsif Attribute_Name (N) = Name_Stub_Type then - - -- This is handled in Analyze_Attribute - - Analyze (N); - - -- All other attributes are invalid in a subtype mark - - else - Error_Msg_N ("invalid attribute in subtype mark", N); - end if; - - else - Analyze (N); - - if Is_Entity_Name (N) then - T_Name := Entity (N); - else - Error_Msg_N ("subtype mark required in this context", N); - Set_Etype (N, Any_Type); - return; - end if; - - if T_Name = Any_Id or else Etype (N) = Any_Type then - - -- Undefined id. Make it into a valid type - - Set_Entity (N, Any_Type); - - elsif not Is_Type (T_Name) - and then T_Name /= Standard_Void_Type - then - Error_Msg_Sloc := Sloc (T_Name); - Error_Msg_N ("subtype mark required in this context", N); - Error_Msg_NE ("\\found & declared#", N, T_Name); - Set_Entity (N, Any_Type); - - else - -- If the type is an incomplete type created to handle - -- anonymous access components of a record type, then the - -- incomplete type is the visible entity and subsequent - -- references will point to it. Mark the original full - -- type as referenced, to prevent spurious warnings. - - if Is_Incomplete_Type (T_Name) - and then Present (Full_View (T_Name)) - and then not Comes_From_Source (T_Name) - then - Set_Referenced (Full_View (T_Name)); - end if; - - T_Name := Get_Full_View (T_Name); - - -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through - -- limited-with clauses - - if From_With_Type (T_Name) - and then Ekind (T_Name) in Incomplete_Kind - and then Present (Non_Limited_View (T_Name)) - and then Is_Interface (Non_Limited_View (T_Name)) - then - T_Name := Non_Limited_View (T_Name); - end if; - - if In_Open_Scopes (T_Name) then - if Ekind (Base_Type (T_Name)) = E_Task_Type then - - -- In Ada 2005, a task name can be used in an access - -- definition within its own body. - - if Ada_Version >= Ada_05 - and then Nkind (Parent (N)) = N_Access_Definition - then - Set_Entity (N, T_Name); - Set_Etype (N, T_Name); - return; - - else - Error_Msg_N - ("task type cannot be used as type mark " & - "within its own spec or body", N); - end if; - - elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then - - -- In Ada 2005, a protected name can be used in an access - -- definition within its own body. - - if Ada_Version >= Ada_05 - and then Nkind (Parent (N)) = N_Access_Definition - then - Set_Entity (N, T_Name); - Set_Etype (N, T_Name); - return; - - else - Error_Msg_N - ("protected type cannot be used as type mark " & - "within its own spec or body", N); - end if; - - else - Error_Msg_N ("type declaration cannot refer to itself", N); - end if; - - Set_Etype (N, Any_Type); - Set_Entity (N, Any_Type); - Set_Error_Posted (T_Name); - return; - end if; - - Set_Entity (N, T_Name); - Set_Etype (N, T_Name); - end if; - end if; - - if Present (Etype (N)) and then Comes_From_Source (N) then - if Is_Fixed_Point_Type (Etype (N)) then - Check_Restriction (No_Fixed_Point, N); - elsif Is_Floating_Point_Type (Etype (N)) then - Check_Restriction (No_Floating_Point, N); - end if; - end if; - end Find_Type; - - ------------------------------------ - -- Has_Implicit_Character_Literal -- - ------------------------------------ - - function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is - Id : Entity_Id; - Found : Boolean := False; - P : constant Entity_Id := Entity (Prefix (N)); - Priv_Id : Entity_Id := Empty; - - begin - if Ekind (P) = E_Package - and then not In_Open_Scopes (P) - then - Priv_Id := First_Private_Entity (P); - end if; - - if P = Standard_Standard then - Change_Selected_Component_To_Expanded_Name (N); - Rewrite (N, Selector_Name (N)); - Analyze (N); - Set_Etype (Original_Node (N), Standard_Character); - return True; - end if; - - Id := First_Entity (P); - while Present (Id) - and then Id /= Priv_Id - loop - if Is_Standard_Character_Type (Id) - and then Id = Base_Type (Id) - then - -- We replace the node with the literal itself, resolve as a - -- character, and set the type correctly. - - if not Found then - Change_Selected_Component_To_Expanded_Name (N); - Rewrite (N, Selector_Name (N)); - Analyze (N); - Set_Etype (N, Id); - Set_Etype (Original_Node (N), Id); - Found := True; - - else - -- More than one type derived from Character in given scope. - -- Collect all possible interpretations. - - Add_One_Interp (N, Id, Id); - end if; - end if; - - Next_Entity (Id); - end loop; - - return Found; - end Has_Implicit_Character_Literal; - - ---------------------- - -- Has_Private_With -- - ---------------------- - - function Has_Private_With (E : Entity_Id) return Boolean is - Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit); - Item : Node_Id; - - begin - Item := First (Context_Items (Comp_Unit)); - while Present (Item) loop - if Nkind (Item) = N_With_Clause - and then Private_Present (Item) - and then Entity (Name (Item)) = E - then - return True; - end if; - - Next (Item); - end loop; - - return False; - end Has_Private_With; - - --------------------------- - -- Has_Implicit_Operator -- - --------------------------- - - function Has_Implicit_Operator (N : Node_Id) return Boolean is - Op_Id : constant Name_Id := Chars (Selector_Name (N)); - P : constant Entity_Id := Entity (Prefix (N)); - Id : Entity_Id; - Priv_Id : Entity_Id := Empty; - - procedure Add_Implicit_Operator - (T : Entity_Id; - Op_Type : Entity_Id := Empty); - -- Add implicit interpretation to node N, using the type for which a - -- predefined operator exists. If the operator yields a boolean type, - -- the Operand_Type is implicitly referenced by the operator, and a - -- reference to it must be generated. - - --------------------------- - -- Add_Implicit_Operator -- - --------------------------- - - procedure Add_Implicit_Operator - (T : Entity_Id; - Op_Type : Entity_Id := Empty) - is - Predef_Op : Entity_Id; - - begin - Predef_Op := Current_Entity (Selector_Name (N)); - - while Present (Predef_Op) - and then Scope (Predef_Op) /= Standard_Standard - loop - Predef_Op := Homonym (Predef_Op); - end loop; - - if Nkind (N) = N_Selected_Component then - Change_Selected_Component_To_Expanded_Name (N); - end if; - - Add_One_Interp (N, Predef_Op, T); - - -- For operators with unary and binary interpretations, add both - - if Present (Homonym (Predef_Op)) then - Add_One_Interp (N, Homonym (Predef_Op), T); - end if; - - -- The node is a reference to a predefined operator, and - -- an implicit reference to the type of its operands. - - if Present (Op_Type) then - Generate_Operator_Reference (N, Op_Type); - else - Generate_Operator_Reference (N, T); - end if; - end Add_Implicit_Operator; - - -- Start of processing for Has_Implicit_Operator - - begin - if Ekind (P) = E_Package - and then not In_Open_Scopes (P) - then - Priv_Id := First_Private_Entity (P); - end if; - - Id := First_Entity (P); - - case Op_Id is - - -- Boolean operators: an implicit declaration exists if the scope - -- contains a declaration for a derived Boolean type, or for an - -- array of Boolean type. - - when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor => - while Id /= Priv_Id loop - if Valid_Boolean_Arg (Id) - and then Id = Base_Type (Id) - then - Add_Implicit_Operator (Id); - return True; - end if; - - Next_Entity (Id); - end loop; - - -- Equality: look for any non-limited type (result is Boolean) - - when Name_Op_Eq | Name_Op_Ne => - while Id /= Priv_Id loop - if Is_Type (Id) - and then not Is_Limited_Type (Id) - and then Id = Base_Type (Id) - then - Add_Implicit_Operator (Standard_Boolean, Id); - return True; - end if; - - Next_Entity (Id); - end loop; - - -- Comparison operators: scalar type, or array of scalar - - when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge => - while Id /= Priv_Id loop - if (Is_Scalar_Type (Id) - or else (Is_Array_Type (Id) - and then Is_Scalar_Type (Component_Type (Id)))) - and then Id = Base_Type (Id) - then - Add_Implicit_Operator (Standard_Boolean, Id); - return True; - end if; - - Next_Entity (Id); - end loop; - - -- Arithmetic operators: any numeric type - - when Name_Op_Abs | - Name_Op_Add | - Name_Op_Mod | - Name_Op_Rem | - Name_Op_Subtract | - Name_Op_Multiply | - Name_Op_Divide | - Name_Op_Expon => - while Id /= Priv_Id loop - if Is_Numeric_Type (Id) - and then Id = Base_Type (Id) - then - Add_Implicit_Operator (Id); - return True; - end if; - - Next_Entity (Id); - end loop; - - -- Concatenation: any one-dimensional array type - - when Name_Op_Concat => - while Id /= Priv_Id loop - if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1 - and then Id = Base_Type (Id) - then - Add_Implicit_Operator (Id); - return True; - end if; - - Next_Entity (Id); - end loop; - - -- What is the others condition here? Should we be using a - -- subtype of Name_Id that would restrict to operators ??? - - when others => null; - end case; - - -- If we fall through, then we do not have an implicit operator - - return False; - - end Has_Implicit_Operator; - - -------------------- - -- In_Open_Scopes -- - -------------------- - - function In_Open_Scopes (S : Entity_Id) return Boolean is - begin - -- Several scope stacks are maintained by Scope_Stack. The base of the - -- currently active scope stack is denoted by the Is_Active_Stack_Base - -- flag in the scope stack entry. Note that the scope stacks used to - -- simply be delimited implicitly by the presence of Standard_Standard - -- at their base, but there now are cases where this is not sufficient - -- because Standard_Standard actually may appear in the middle of the - -- active set of scopes. - - for J in reverse 0 .. Scope_Stack.Last loop - if Scope_Stack.Table (J).Entity = S then - return True; - end if; - - -- Check Is_Active_Stack_Base to tell us when to stop, as there are - -- cases where Standard_Standard appears in the middle of the active - -- set of scopes. This affects the declaration and overriding of - -- private inherited operations in instantiations of generic child - -- units. - - exit when Scope_Stack.Table (J).Is_Active_Stack_Base; - end loop; - - return False; - end In_Open_Scopes; - - ----------------------------- - -- Inherit_Renamed_Profile -- - ----------------------------- - - procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is - New_F : Entity_Id; - Old_F : Entity_Id; - Old_T : Entity_Id; - New_T : Entity_Id; - - begin - if Ekind (Old_S) = E_Operator then - New_F := First_Formal (New_S); - - while Present (New_F) loop - Set_Etype (New_F, Base_Type (Etype (New_F))); - Next_Formal (New_F); - end loop; - - Set_Etype (New_S, Base_Type (Etype (New_S))); - - else - New_F := First_Formal (New_S); - Old_F := First_Formal (Old_S); - - while Present (New_F) loop - New_T := Etype (New_F); - Old_T := Etype (Old_F); - - -- If the new type is a renaming of the old one, as is the - -- case for actuals in instances, retain its name, to simplify - -- later disambiguation. - - if Nkind (Parent (New_T)) = N_Subtype_Declaration - and then Is_Entity_Name (Subtype_Indication (Parent (New_T))) - and then Entity (Subtype_Indication (Parent (New_T))) = Old_T - then - null; - else - Set_Etype (New_F, Old_T); - end if; - - Next_Formal (New_F); - Next_Formal (Old_F); - end loop; - - if Ekind (Old_S) = E_Function - or else Ekind (Old_S) = E_Enumeration_Literal - then - Set_Etype (New_S, Etype (Old_S)); - end if; - end if; - end Inherit_Renamed_Profile; - - ---------------- - -- Initialize -- - ---------------- - - procedure Initialize is - begin - Urefs.Init; - end Initialize; - - ------------------------- - -- Install_Use_Clauses -- - ------------------------- - - procedure Install_Use_Clauses - (Clause : Node_Id; - Force_Installation : Boolean := False) - is - U : Node_Id; - P : Node_Id; - Id : Entity_Id; - - begin - U := Clause; - while Present (U) loop - - -- Case of USE package - - if Nkind (U) = N_Use_Package_Clause then - P := First (Names (U)); - while Present (P) loop - Id := Entity (P); - - if Ekind (Id) = E_Package then - if In_Use (Id) then - Note_Redundant_Use (P); - - elsif Present (Renamed_Object (Id)) - and then In_Use (Renamed_Object (Id)) - then - Note_Redundant_Use (P); - - elsif Force_Installation or else Applicable_Use (P) then - Use_One_Package (Id, U); - - end if; - end if; - - Next (P); - end loop; - - -- Case of USE TYPE - - else - P := First (Subtype_Marks (U)); - while Present (P) loop - if not Is_Entity_Name (P) - or else No (Entity (P)) - then - null; - - elsif Entity (P) /= Any_Type then - Use_One_Type (P); - end if; - - Next (P); - end loop; - end if; - - Next_Use_Clause (U); - end loop; - end Install_Use_Clauses; - - ------------------------------------- - -- Is_Appropriate_For_Entry_Prefix -- - ------------------------------------- - - function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is - P_Type : Entity_Id := T; - - begin - if Is_Access_Type (P_Type) then - P_Type := Designated_Type (P_Type); - end if; - - return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type); - end Is_Appropriate_For_Entry_Prefix; - - ------------------------------- - -- Is_Appropriate_For_Record -- - ------------------------------- - - function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is - - function Has_Components (T1 : Entity_Id) return Boolean; - -- Determine if given type has components (i.e. is either a record - -- type or a type that has discriminants). - - -------------------- - -- Has_Components -- - -------------------- - - function Has_Components (T1 : Entity_Id) return Boolean is - begin - return Is_Record_Type (T1) - or else (Is_Private_Type (T1) and then Has_Discriminants (T1)) - or else (Is_Task_Type (T1) and then Has_Discriminants (T1)) - or else (Is_Incomplete_Type (T1) - and then From_With_Type (T1) - and then Present (Non_Limited_View (T1)) - and then Is_Record_Type - (Get_Full_View (Non_Limited_View (T1)))); - end Has_Components; - - -- Start of processing for Is_Appropriate_For_Record - - begin - return - Present (T) - and then (Has_Components (T) - or else (Is_Access_Type (T) - and then Has_Components (Designated_Type (T)))); - end Is_Appropriate_For_Record; - - ------------------------ - -- Note_Redundant_Use -- - ------------------------ - - procedure Note_Redundant_Use (Clause : Node_Id) is - Pack_Name : constant Entity_Id := Entity (Clause); - Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name); - Decl : constant Node_Id := Parent (Clause); - - Prev_Use : Node_Id := Empty; - Redundant : Node_Id := Empty; - -- The Use_Clause which is actually redundant. In the simplest case - -- it is Pack itself, but when we compile a body we install its - -- context before that of its spec, in which case it is the use_clause - -- in the spec that will appear to be redundant, and we want the - -- warning to be placed on the body. Similar complications appear when - -- the redundancy is between a child unit and one of its ancestors. - - begin - Set_Redundant_Use (Clause, True); - - if not Comes_From_Source (Clause) - or else In_Instance - or else not Warn_On_Redundant_Constructs - then - return; - end if; - - if not Is_Compilation_Unit (Current_Scope) then - - -- If the use_clause is in an inner scope, it is made redundant - -- by some clause in the current context, with one exception: - -- If we're compiling a nested package body, and the use_clause - -- comes from the corresponding spec, the clause is not necessarily - -- fully redundant, so we should not warn. If a warning was - -- warranted, it would have been given when the spec was processed. - - if Nkind (Parent (Decl)) = N_Package_Specification then - declare - Package_Spec_Entity : constant Entity_Id := - Defining_Unit_Name (Parent (Decl)); - begin - if In_Package_Body (Package_Spec_Entity) then - return; - end if; - end; - end if; - - Redundant := Clause; - Prev_Use := Cur_Use; - - elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then - declare - Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use); - New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause); - Scop : Entity_Id; - - begin - if Cur_Unit = New_Unit then - - -- Redundant clause in same body - - Redundant := Clause; - Prev_Use := Cur_Use; - - elsif Cur_Unit = Current_Sem_Unit then - - -- If the new clause is not in the current unit it has been - -- analyzed first, and it makes the other one redundant. - -- However, if the new clause appears in a subunit, Cur_Unit - -- is still the parent, and in that case the redundant one - -- is the one appearing in the subunit. - - if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then - Redundant := Clause; - Prev_Use := Cur_Use; - - -- Most common case: redundant clause in body, - -- original clause in spec. Current scope is spec entity. - - elsif - Current_Scope = - Defining_Entity ( - Unit (Library_Unit (Cunit (Current_Sem_Unit)))) - then - Redundant := Cur_Use; - Prev_Use := Clause; - - else - -- The new clause may appear in an unrelated unit, when - -- the parents of a generic are being installed prior to - -- instantiation. In this case there must be no warning. - -- We detect this case by checking whether the current top - -- of the stack is related to the current compilation. - - Scop := Current_Scope; - while Present (Scop) - and then Scop /= Standard_Standard - loop - if Is_Compilation_Unit (Scop) - and then not Is_Child_Unit (Scop) - then - return; - - elsif Scop = Cunit_Entity (Current_Sem_Unit) then - exit; - end if; - - Scop := Scope (Scop); - end loop; - - Redundant := Cur_Use; - Prev_Use := Clause; - end if; - - elsif New_Unit = Current_Sem_Unit then - Redundant := Clause; - Prev_Use := Cur_Use; - - else - -- Neither is the current unit, so they appear in parent or - -- sibling units. Warning will be emitted elsewhere. - - return; - end if; - end; - - elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration - and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit)))) - then - -- Use_clause is in child unit of current unit, and the child - -- unit appears in the context of the body of the parent, so it - -- has been installed first, even though it is the redundant one. - -- Depending on their placement in the context, the visible or the - -- private parts of the two units, either might appear as redundant, - -- but the message has to be on the current unit. - - if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then - Redundant := Cur_Use; - Prev_Use := Clause; - else - Redundant := Clause; - Prev_Use := Cur_Use; - end if; - - -- If the new use clause appears in the private part of a parent unit - -- it may appear to be redundant w.r.t. a use clause in a child unit, - -- but the previous use clause was needed in the visible part of the - -- child, and no warning should be emitted. - - if Nkind (Parent (Decl)) = N_Package_Specification - and then - List_Containing (Decl) = Private_Declarations (Parent (Decl)) - then - declare - Par : constant Entity_Id := Defining_Entity (Parent (Decl)); - Spec : constant Node_Id := - Specification (Unit (Cunit (Current_Sem_Unit))); - - begin - if Is_Compilation_Unit (Par) - and then Par /= Cunit_Entity (Current_Sem_Unit) - and then Parent (Cur_Use) = Spec - and then - List_Containing (Cur_Use) = Visible_Declarations (Spec) - then - return; - end if; - end; - end if; - - -- Finally, if the current use clause is in the context then - -- the clause is redundant when it is nested within the unit. - - elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit - and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit - and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause) - then - Redundant := Clause; - Prev_Use := Cur_Use; - - else - null; - end if; - - if Present (Redundant) then - Error_Msg_Sloc := Sloc (Prev_Use); - Error_Msg_NE - ("& is already use-visible through previous use clause #?", - Redundant, Pack_Name); - end if; - end Note_Redundant_Use; - - --------------- - -- Pop_Scope -- - --------------- - - procedure Pop_Scope is - SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last); - - begin - if Debug_Flag_E then - Write_Info; - end if; - - Scope_Suppress := SST.Save_Scope_Suppress; - Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top; - Check_Policy_List := SST.Save_Check_Policy_List; - - if Debug_Flag_W then - Write_Str ("--> exiting scope: "); - Write_Name (Chars (Current_Scope)); - Write_Str (", Depth="); - Write_Int (Int (Scope_Stack.Last)); - Write_Eol; - end if; - - End_Use_Clauses (SST.First_Use_Clause); - - -- If the actions to be wrapped are still there they will get lost - -- causing incomplete code to be generated. It is better to abort in - -- this case (and we do the abort even with assertions off since the - -- penalty is incorrect code generation) - - if SST.Actions_To_Be_Wrapped_Before /= No_List - or else - SST.Actions_To_Be_Wrapped_After /= No_List - then - return; - end if; - - -- Free last subprogram name if allocated, and pop scope - - Free (SST.Last_Subprogram_Name); - Scope_Stack.Decrement_Last; - end Pop_Scope; - - --------------- - -- Push_Scope -- - --------------- - - procedure Push_Scope (S : Entity_Id) is - E : Entity_Id; - - begin - if Ekind (S) = E_Void then - null; - - -- Set scope depth if not a non-concurrent type, and we have not - -- yet set the scope depth. This means that we have the first - -- occurrence of the scope, and this is where the depth is set. - - elsif (not Is_Type (S) or else Is_Concurrent_Type (S)) - and then not Scope_Depth_Set (S) - then - if S = Standard_Standard then - Set_Scope_Depth_Value (S, Uint_0); - - elsif Is_Child_Unit (S) then - Set_Scope_Depth_Value (S, Uint_1); - - elsif not Is_Record_Type (Current_Scope) then - if Ekind (S) = E_Loop then - Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope)); - else - Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1); - end if; - end if; - end if; - - Scope_Stack.Increment_Last; - - declare - SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last); - - begin - SST.Entity := S; - SST.Save_Scope_Suppress := Scope_Suppress; - SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top; - SST.Save_Check_Policy_List := Check_Policy_List; - - if Scope_Stack.Last > Scope_Stack.First then - SST.Component_Alignment_Default := Scope_Stack.Table - (Scope_Stack.Last - 1). - Component_Alignment_Default; - end if; - - SST.Last_Subprogram_Name := null; - SST.Is_Transient := False; - SST.Node_To_Be_Wrapped := Empty; - SST.Pending_Freeze_Actions := No_List; - SST.Actions_To_Be_Wrapped_Before := No_List; - SST.Actions_To_Be_Wrapped_After := No_List; - SST.First_Use_Clause := Empty; - SST.Is_Active_Stack_Base := False; - SST.Previous_Visibility := False; - end; - - if Debug_Flag_W then - Write_Str ("--> new scope: "); - Write_Name (Chars (Current_Scope)); - Write_Str (", Id="); - Write_Int (Int (Current_Scope)); - Write_Str (", Depth="); - Write_Int (Int (Scope_Stack.Last)); - Write_Eol; - end if; - - -- Deal with copying flags from the previous scope to this one. This - -- is not necessary if either scope is standard, or if the new scope - -- is a child unit. - - if S /= Standard_Standard - and then Scope (S) /= Standard_Standard - and then not Is_Child_Unit (S) - then - E := Scope (S); - - if Nkind (E) not in N_Entity then - return; - end if; - - -- Copy categorization flags from Scope (S) to S, this is not done - -- when Scope (S) is Standard_Standard since propagation is from - -- library unit entity inwards. Copy other relevant attributes as - -- well (Discard_Names in particular). - - -- We only propagate inwards for library level entities, - -- inner level subprograms do not inherit the categorization. - - if Is_Library_Level_Entity (S) then - Set_Is_Preelaborated (S, Is_Preelaborated (E)); - Set_Is_Shared_Passive (S, Is_Shared_Passive (E)); - Set_Discard_Names (S, Discard_Names (E)); - Set_Suppress_Value_Tracking_On_Call - (S, Suppress_Value_Tracking_On_Call (E)); - Set_Categorization_From_Scope (E => S, Scop => E); - end if; - end if; - end Push_Scope; - - --------------------- - -- Premature_Usage -- - --------------------- - - procedure Premature_Usage (N : Node_Id) is - Kind : constant Node_Kind := Nkind (Parent (Entity (N))); - E : Entity_Id := Entity (N); - - begin - -- Within an instance, the analysis of the actual for a formal object - -- does not see the name of the object itself. This is significant only - -- if the object is an aggregate, where its analysis does not do any - -- name resolution on component associations. (see 4717-008). In such a - -- case, look for the visible homonym on the chain. - - if In_Instance - and then Present (Homonym (E)) - then - E := Homonym (E); - - while Present (E) - and then not In_Open_Scopes (Scope (E)) - loop - E := Homonym (E); - end loop; - - if Present (E) then - Set_Entity (N, E); - Set_Etype (N, Etype (E)); - return; - end if; - end if; - - if Kind = N_Component_Declaration then - Error_Msg_N - ("component&! cannot be used before end of record declaration", N); - - elsif Kind = N_Parameter_Specification then - Error_Msg_N - ("formal parameter&! cannot be used before end of specification", - N); - - elsif Kind = N_Discriminant_Specification then - Error_Msg_N - ("discriminant&! cannot be used before end of discriminant part", - N); - - elsif Kind = N_Procedure_Specification - or else Kind = N_Function_Specification - then - Error_Msg_N - ("subprogram&! cannot be used before end of its declaration", - N); - - elsif Kind = N_Full_Type_Declaration then - Error_Msg_N - ("type& cannot be used before end of its declaration!", N); - - else - Error_Msg_N - ("object& cannot be used before end of its declaration!", N); - end if; - end Premature_Usage; - - ------------------------ - -- Present_System_Aux -- - ------------------------ - - function Present_System_Aux (N : Node_Id := Empty) return Boolean is - Loc : Source_Ptr; - Aux_Name : Unit_Name_Type; - Unum : Unit_Number_Type; - Withn : Node_Id; - With_Sys : Node_Id; - The_Unit : Node_Id; - - function Find_System (C_Unit : Node_Id) return Entity_Id; - -- Scan context clause of compilation unit to find with_clause - -- for System. - - ----------------- - -- Find_System -- - ----------------- - - function Find_System (C_Unit : Node_Id) return Entity_Id is - With_Clause : Node_Id; - - begin - With_Clause := First (Context_Items (C_Unit)); - while Present (With_Clause) loop - if (Nkind (With_Clause) = N_With_Clause - and then Chars (Name (With_Clause)) = Name_System) - and then Comes_From_Source (With_Clause) - then - return With_Clause; - end if; - - Next (With_Clause); - end loop; - - return Empty; - end Find_System; - - -- Start of processing for Present_System_Aux - - begin - -- The child unit may have been loaded and analyzed already - - if Present (System_Aux_Id) then - return True; - - -- If no previous pragma for System.Aux, nothing to load - - elsif No (System_Extend_Unit) then - return False; - - -- Use the unit name given in the pragma to retrieve the unit. - -- Verify that System itself appears in the context clause of the - -- current compilation. If System is not present, an error will - -- have been reported already. - - else - With_Sys := Find_System (Cunit (Current_Sem_Unit)); - - The_Unit := Unit (Cunit (Current_Sem_Unit)); - - if No (With_Sys) - and then - (Nkind (The_Unit) = N_Package_Body - or else (Nkind (The_Unit) = N_Subprogram_Body - and then - not Acts_As_Spec (Cunit (Current_Sem_Unit)))) - then - With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit))); - end if; - - if No (With_Sys) - and then Present (N) - then - -- If we are compiling a subunit, we need to examine its - -- context as well (Current_Sem_Unit is the parent unit); - - The_Unit := Parent (N); - while Nkind (The_Unit) /= N_Compilation_Unit loop - The_Unit := Parent (The_Unit); - end loop; - - if Nkind (Unit (The_Unit)) = N_Subunit then - With_Sys := Find_System (The_Unit); - end if; - end if; - - if No (With_Sys) then - return False; - end if; - - Loc := Sloc (With_Sys); - Get_Name_String (Chars (Expression (System_Extend_Unit))); - Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len); - Name_Buffer (1 .. 7) := "system."; - Name_Buffer (Name_Len + 8) := '%'; - Name_Buffer (Name_Len + 9) := 's'; - Name_Len := Name_Len + 9; - Aux_Name := Name_Find; - - Unum := - Load_Unit - (Load_Name => Aux_Name, - Required => False, - Subunit => False, - Error_Node => With_Sys); - - if Unum /= No_Unit then - Semantics (Cunit (Unum)); - System_Aux_Id := - Defining_Entity (Specification (Unit (Cunit (Unum)))); - - Withn := - Make_With_Clause (Loc, - Name => - Make_Expanded_Name (Loc, - Chars => Chars (System_Aux_Id), - Prefix => New_Reference_To (Scope (System_Aux_Id), Loc), - Selector_Name => New_Reference_To (System_Aux_Id, Loc))); - - Set_Entity (Name (Withn), System_Aux_Id); - - Set_Library_Unit (Withn, Cunit (Unum)); - Set_Corresponding_Spec (Withn, System_Aux_Id); - Set_First_Name (Withn, True); - Set_Implicit_With (Withn, True); - - Insert_After (With_Sys, Withn); - Mark_Rewrite_Insertion (Withn); - Set_Context_Installed (Withn); - - return True; - - -- Here if unit load failed - - else - Error_Msg_Name_1 := Name_System; - Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit)); - Error_Msg_N - ("extension package `%.%` does not exist", - Opt.System_Extend_Unit); - return False; - end if; - end if; - end Present_System_Aux; - - ------------------------- - -- Restore_Scope_Stack -- - ------------------------- - - procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is - E : Entity_Id; - S : Entity_Id; - Comp_Unit : Node_Id; - In_Child : Boolean := False; - Full_Vis : Boolean := True; - SS_Last : constant Int := Scope_Stack.Last; - - begin - -- Restore visibility of previous scope stack, if any - - for J in reverse 0 .. Scope_Stack.Last loop - exit when Scope_Stack.Table (J).Entity = Standard_Standard - or else No (Scope_Stack.Table (J).Entity); - - S := Scope_Stack.Table (J).Entity; - - if not Is_Hidden_Open_Scope (S) then - - -- If the parent scope is hidden, its entities are hidden as - -- well, unless the entity is the instantiation currently - -- being analyzed. - - if not Is_Hidden_Open_Scope (Scope (S)) - or else not Analyzed (Parent (S)) - or else Scope (S) = Standard_Standard - then - Set_Is_Immediately_Visible (S, True); - end if; - - E := First_Entity (S); - while Present (E) loop - if Is_Child_Unit (E) then - Set_Is_Immediately_Visible (E, - Is_Visible_Child_Unit (E) or else In_Open_Scopes (E)); - else - Set_Is_Immediately_Visible (E, True); - end if; - - Next_Entity (E); - - if not Full_Vis then - exit when E = First_Private_Entity (S); - end if; - end loop; - - -- The visibility of child units (siblings of current compilation) - -- must be restored in any case. Their declarations may appear - -- after the private part of the parent. - - if not Full_Vis then - while Present (E) loop - if Is_Child_Unit (E) then - Set_Is_Immediately_Visible (E, - Is_Visible_Child_Unit (E) or else In_Open_Scopes (E)); - end if; - - Next_Entity (E); - end loop; - end if; - end if; - - if Is_Child_Unit (S) - and not In_Child -- check only for current unit - then - In_Child := True; - - -- Restore visibility of parents according to whether the child - -- is private and whether we are in its visible part. - - Comp_Unit := Parent (Unit_Declaration_Node (S)); - - if Nkind (Comp_Unit) = N_Compilation_Unit - and then Private_Present (Comp_Unit) - then - Full_Vis := True; - - elsif Is_Package_Or_Generic_Package (S) - and then (In_Private_Part (S) - or else In_Package_Body (S)) - then - Full_Vis := True; - - -- if S is the scope of some instance (which has already been - -- seen on the stack) it does not affect the visibility of - -- other scopes. - - elsif Is_Hidden_Open_Scope (S) then - null; - - elsif (Ekind (S) = E_Procedure - or else Ekind (S) = E_Function) - and then Has_Completion (S) - then - Full_Vis := True; - else - Full_Vis := False; - end if; - else - Full_Vis := True; - end if; - end loop; - - if SS_Last >= Scope_Stack.First - and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard - and then Handle_Use - then - Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause); - end if; - end Restore_Scope_Stack; - - ---------------------- - -- Save_Scope_Stack -- - ---------------------- - - procedure Save_Scope_Stack (Handle_Use : Boolean := True) is - E : Entity_Id; - S : Entity_Id; - SS_Last : constant Int := Scope_Stack.Last; - - begin - if SS_Last >= Scope_Stack.First - and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard - then - if Handle_Use then - End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause); - end if; - - -- If the call is from within a compilation unit, as when called from - -- Rtsfind, make current entries in scope stack invisible while we - -- analyze the new unit. - - for J in reverse 0 .. SS_Last loop - exit when Scope_Stack.Table (J).Entity = Standard_Standard - or else No (Scope_Stack.Table (J).Entity); - - S := Scope_Stack.Table (J).Entity; - Set_Is_Immediately_Visible (S, False); - - E := First_Entity (S); - while Present (E) loop - Set_Is_Immediately_Visible (E, False); - Next_Entity (E); - end loop; - end loop; - - end if; - end Save_Scope_Stack; - - ------------- - -- Set_Use -- - ------------- - - procedure Set_Use (L : List_Id) is - Decl : Node_Id; - Pack_Name : Node_Id; - Pack : Entity_Id; - Id : Entity_Id; - - begin - if Present (L) then - Decl := First (L); - while Present (Decl) loop - if Nkind (Decl) = N_Use_Package_Clause then - Chain_Use_Clause (Decl); - - Pack_Name := First (Names (Decl)); - while Present (Pack_Name) loop - Pack := Entity (Pack_Name); - - if Ekind (Pack) = E_Package - and then Applicable_Use (Pack_Name) - then - Use_One_Package (Pack, Decl); - end if; - - Next (Pack_Name); - end loop; - - elsif Nkind (Decl) = N_Use_Type_Clause then - Chain_Use_Clause (Decl); - - Id := First (Subtype_Marks (Decl)); - while Present (Id) loop - if Entity (Id) /= Any_Type then - Use_One_Type (Id); - end if; - - Next (Id); - end loop; - end if; - - Next (Decl); - end loop; - end if; - end Set_Use; - - --------------------- - -- Use_One_Package -- - --------------------- - - procedure Use_One_Package (P : Entity_Id; N : Node_Id) is - Id : Entity_Id; - Prev : Entity_Id; - Current_Instance : Entity_Id := Empty; - Real_P : Entity_Id; - Private_With_OK : Boolean := False; - - begin - if Ekind (P) /= E_Package then - return; - end if; - - Set_In_Use (P); - Set_Current_Use_Clause (P, N); - - -- Ada 2005 (AI-50217): Check restriction - - if From_With_Type (P) then - Error_Msg_N ("limited withed package cannot appear in use clause", N); - end if; - - -- Find enclosing instance, if any - - if In_Instance then - Current_Instance := Current_Scope; - while not Is_Generic_Instance (Current_Instance) loop - Current_Instance := Scope (Current_Instance); - end loop; - - if No (Hidden_By_Use_Clause (N)) then - Set_Hidden_By_Use_Clause (N, New_Elmt_List); - end if; - end if; - - -- If unit is a package renaming, indicate that the renamed - -- package is also in use (the flags on both entities must - -- remain consistent, and a subsequent use of either of them - -- should be recognized as redundant). - - if Present (Renamed_Object (P)) then - Set_In_Use (Renamed_Object (P)); - Set_Current_Use_Clause (Renamed_Object (P), N); - Real_P := Renamed_Object (P); - else - Real_P := P; - end if; - - -- Ada 2005 (AI-262): Check the use_clause of a private withed package - -- found in the private part of a package specification - - if In_Private_Part (Current_Scope) - and then Has_Private_With (P) - and then Is_Child_Unit (Current_Scope) - and then Is_Child_Unit (P) - and then Is_Ancestor_Package (Scope (Current_Scope), P) - then - Private_With_OK := True; - end if; - - -- Loop through entities in one package making them potentially - -- use-visible. - - Id := First_Entity (P); - while Present (Id) - and then (Id /= First_Private_Entity (P) - or else Private_With_OK) -- Ada 2005 (AI-262) - loop - Prev := Current_Entity (Id); - while Present (Prev) loop - if Is_Immediately_Visible (Prev) - and then (not Is_Overloadable (Prev) - or else not Is_Overloadable (Id) - or else (Type_Conformant (Id, Prev))) - then - if No (Current_Instance) then - - -- Potentially use-visible entity remains hidden - - goto Next_Usable_Entity; - - -- A use clause within an instance hides outer global entities, - -- which are not used to resolve local entities in the - -- instance. Note that the predefined entities in Standard - -- could not have been hidden in the generic by a use clause, - -- and therefore remain visible. Other compilation units whose - -- entities appear in Standard must be hidden in an instance. - - -- To determine whether an entity is external to the instance - -- we compare the scope depth of its scope with that of the - -- current instance. However, a generic actual of a subprogram - -- instance is declared in the wrapper package but will not be - -- hidden by a use-visible entity. - - -- If Id is called Standard, the predefined package with the - -- same name is in the homonym chain. It has to be ignored - -- because it has no defined scope (being the only entity in - -- the system with this mandated behavior). - - elsif not Is_Hidden (Id) - and then Present (Scope (Prev)) - and then not Is_Wrapper_Package (Scope (Prev)) - and then Scope_Depth (Scope (Prev)) < - Scope_Depth (Current_Instance) - and then (Scope (Prev) /= Standard_Standard - or else Sloc (Prev) > Standard_Location) - then - Set_Is_Potentially_Use_Visible (Id); - Set_Is_Immediately_Visible (Prev, False); - Append_Elmt (Prev, Hidden_By_Use_Clause (N)); - end if; - - -- A user-defined operator is not use-visible if the predefined - -- operator for the type is immediately visible, which is the case - -- if the type of the operand is in an open scope. This does not - -- apply to user-defined operators that have operands of different - -- types, because the predefined mixed mode operations (multiply - -- and divide) apply to universal types and do not hide anything. - - elsif Ekind (Prev) = E_Operator - and then Operator_Matches_Spec (Prev, Id) - and then In_Open_Scopes - (Scope (Base_Type (Etype (First_Formal (Id))))) - and then (No (Next_Formal (First_Formal (Id))) - or else Etype (First_Formal (Id)) - = Etype (Next_Formal (First_Formal (Id))) - or else Chars (Prev) = Name_Op_Expon) - then - goto Next_Usable_Entity; - end if; - - Prev := Homonym (Prev); - end loop; - - -- On exit, we know entity is not hidden, unless it is private - - if not Is_Hidden (Id) - and then ((not Is_Child_Unit (Id)) - or else Is_Visible_Child_Unit (Id)) - then - Set_Is_Potentially_Use_Visible (Id); - - if Is_Private_Type (Id) - and then Present (Full_View (Id)) - then - Set_Is_Potentially_Use_Visible (Full_View (Id)); - end if; - end if; - - <<Next_Usable_Entity>> - Next_Entity (Id); - end loop; - - -- Child units are also made use-visible by a use clause, but they may - -- appear after all visible declarations in the parent entity list. - - while Present (Id) loop - if Is_Child_Unit (Id) - and then Is_Visible_Child_Unit (Id) - then - Set_Is_Potentially_Use_Visible (Id); - end if; - - Next_Entity (Id); - end loop; - - if Chars (Real_P) = Name_System - and then Scope (Real_P) = Standard_Standard - and then Present_System_Aux (N) - then - Use_One_Package (System_Aux_Id, N); - end if; - - end Use_One_Package; - - ------------------ - -- Use_One_Type -- - ------------------ - - procedure Use_One_Type (Id : Node_Id) is - Elmt : Elmt_Id; - Is_Known_Used : Boolean; - Op_List : Elist_Id; - T : Entity_Id; - - function Spec_Reloaded_For_Body return Boolean; - -- Determine whether the compilation unit is a package body and the use - -- type clause is in the spec of the same package. Even though the spec - -- was analyzed first, its context is reloaded when analysing the body. - - ---------------------------- - -- Spec_Reloaded_For_Body -- - ---------------------------- - - function Spec_Reloaded_For_Body return Boolean is - begin - if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then - declare - Spec : constant Node_Id := - Parent (List_Containing (Parent (Id))); - begin - return - Nkind (Spec) = N_Package_Specification - and then Corresponding_Body (Parent (Spec)) = - Cunit_Entity (Current_Sem_Unit); - end; - end if; - - return False; - end Spec_Reloaded_For_Body; - - -- Start of processing for Use_One_Type; - - begin - -- It is the type determined by the subtype mark (8.4(8)) whose - -- operations become potentially use-visible. - - T := Base_Type (Entity (Id)); - - -- Either the type itself is used, the package where it is declared - -- is in use or the entity is declared in the current package, thus - -- use-visible. - - Is_Known_Used := - In_Use (T) - or else In_Use (Scope (T)) - or else Scope (T) = Current_Scope; - - Set_Redundant_Use (Id, - Is_Known_Used or else Is_Potentially_Use_Visible (T)); - - if In_Open_Scopes (Scope (T)) then - null; - - -- A limited view cannot appear in a use_type clause. However, an - -- access type whose designated type is limited has the flag but - -- is not itself a limited view unless we only have a limited view - -- of its enclosing package. - - elsif From_With_Type (T) - and then From_With_Type (Scope (T)) - then - Error_Msg_N - ("incomplete type from limited view " - & "cannot appear in use clause", Id); - - -- If the subtype mark designates a subtype in a different package, - -- we have to check that the parent type is visible, otherwise the - -- use type clause is a noop. Not clear how to do that??? - - elsif not Redundant_Use (Id) then - Set_In_Use (T); - Set_Current_Use_Clause (T, Parent (Id)); - Op_List := Collect_Primitive_Operations (T); - - Elmt := First_Elmt (Op_List); - while Present (Elmt) loop - if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol - or else Chars (Node (Elmt)) in Any_Operator_Name) - and then not Is_Hidden (Node (Elmt)) - then - Set_Is_Potentially_Use_Visible (Node (Elmt)); - end if; - - Next_Elmt (Elmt); - end loop; - end if; - - -- If warning on redundant constructs, check for unnecessary WITH - - if Warn_On_Redundant_Constructs - and then Is_Known_Used - - -- with P; with P; use P; - -- package P is package X is package body X is - -- type T ... use P.T; - - -- The compilation unit is the body of X. GNAT first compiles the - -- spec of X, then proceeds to the body. At that point P is marked - -- as use visible. The analysis then reinstalls the spec along with - -- its context. The use clause P.T is now recognized as redundant, - -- but in the wrong context. Do not emit a warning in such cases. - -- Do not emit a warning either if we are in an instance, there - -- is no redundancy between an outer use_clause and one that appears - -- within the generic. - - and then not Spec_Reloaded_For_Body - and then not In_Instance - then - -- The type already has a use clause - - if In_Use (T) then - - -- Case where we know the current use clause for the type - - if Present (Current_Use_Clause (T)) then - Use_Clause_Known : declare - Clause1 : constant Node_Id := Parent (Id); - Clause2 : constant Node_Id := Current_Use_Clause (T); - Ent1 : Entity_Id; - Ent2 : Entity_Id; - Err_No : Node_Id; - Unit1 : Node_Id; - Unit2 : Node_Id; - - function Entity_Of_Unit (U : Node_Id) return Entity_Id; - -- Return the appropriate entity for determining which unit - -- has a deeper scope: the defining entity for U, unless U - -- is a package instance, in which case we retrieve the - -- entity of the instance spec. - - -------------------- - -- Entity_Of_Unit -- - -------------------- - - function Entity_Of_Unit (U : Node_Id) return Entity_Id is - begin - if Nkind (U) = N_Package_Instantiation - and then Analyzed (U) - then - return Defining_Entity (Instance_Spec (U)); - else - return Defining_Entity (U); - end if; - end Entity_Of_Unit; - - -- Start of processing for Use_Clause_Known - - begin - -- If both current use type clause and the use type - -- clause for the type are at the compilation unit level, - -- one of the units must be an ancestor of the other, and - -- the warning belongs on the descendant. - - if Nkind (Parent (Clause1)) = N_Compilation_Unit - and then - Nkind (Parent (Clause2)) = N_Compilation_Unit - then - Unit1 := Unit (Parent (Clause1)); - Unit2 := Unit (Parent (Clause2)); - - -- There is a redundant use type clause in a child unit. - -- Determine which of the units is more deeply nested. - -- If a unit is a package instance, retrieve the entity - -- and its scope from the instance spec. - - Ent1 := Entity_Of_Unit (Unit1); - Ent2 := Entity_Of_Unit (Unit2); - - if Scope (Ent2) = Standard_Standard then - Error_Msg_Sloc := Sloc (Current_Use_Clause (T)); - Err_No := Clause1; - - elsif Scope (Ent1) = Standard_Standard then - Error_Msg_Sloc := Sloc (Id); - Err_No := Clause2; - - -- If both units are child units, we determine which one - -- is the descendant by the scope distance to the - -- ultimate parent unit. - - else - declare - S1, S2 : Entity_Id; - - begin - S1 := Scope (Ent1); - S2 := Scope (Ent2); - while S1 /= Standard_Standard - and then - S2 /= Standard_Standard - loop - S1 := Scope (S1); - S2 := Scope (S2); - end loop; - - if S1 = Standard_Standard then - Error_Msg_Sloc := Sloc (Id); - Err_No := Clause2; - else - Error_Msg_Sloc := Sloc (Current_Use_Clause (T)); - Err_No := Clause1; - end if; - end; - end if; - - Error_Msg_NE - ("& is already use-visible through previous " - & "use_type_clause #?", Err_No, Id); - - -- Case where current use type clause and the use type - -- clause for the type are not both at the compilation unit - -- level. In this case we don't have location information. - - else - Error_Msg_NE - ("& is already use-visible through previous " - & "use type clause?", Id, Id); - end if; - end Use_Clause_Known; - - -- Here if Current_Use_Clause is not set for T, another case - -- where we do not have the location information available. - - else - Error_Msg_NE - ("& is already use-visible through previous " - & "use type clause?", Id, Id); - end if; - - -- The package where T is declared is already used - - elsif In_Use (Scope (T)) then - Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T))); - Error_Msg_NE - ("& is already use-visible through package use clause #?", - Id, Id); - - -- The current scope is the package where T is declared - - else - Error_Msg_Node_2 := Scope (T); - Error_Msg_NE - ("& is already use-visible inside package &?", Id, Id); - end if; - end if; - end Use_One_Type; - - ---------------- - -- Write_Info -- - ---------------- - - procedure Write_Info is - Id : Entity_Id := First_Entity (Current_Scope); - - begin - -- No point in dumping standard entities - - if Current_Scope = Standard_Standard then - return; - end if; - - Write_Str ("========================================================"); - Write_Eol; - Write_Str (" Defined Entities in "); - Write_Name (Chars (Current_Scope)); - Write_Eol; - Write_Str ("========================================================"); - Write_Eol; - - if No (Id) then - Write_Str ("-- none --"); - Write_Eol; - - else - while Present (Id) loop - Write_Entity_Info (Id, " "); - Next_Entity (Id); - end loop; - end if; - - if Scope (Current_Scope) = Standard_Standard then - - -- Print information on the current unit itself - - Write_Entity_Info (Current_Scope, " "); - end if; - - Write_Eol; - end Write_Info; - - ----------------- - -- Write_Scopes -- - ----------------- - - procedure Write_Scopes is - S : Entity_Id; - begin - for J in reverse 1 .. Scope_Stack.Last loop - S := Scope_Stack.Table (J).Entity; - Write_Int (Int (S)); - Write_Str (" === "); - Write_Name (Chars (S)); - Write_Eol; - end loop; - end Write_Scopes; - -end Sem_Ch8; |