diff options
Diffstat (limited to 'gcc-4.9/gcc/ada/sem_ch10.adb')
| -rw-r--r-- | gcc-4.9/gcc/ada/sem_ch10.adb | 6513 |
1 files changed, 6513 insertions, 0 deletions
diff --git a/gcc-4.9/gcc/ada/sem_ch10.adb b/gcc-4.9/gcc/ada/sem_ch10.adb new file mode 100644 index 000000000..49f7df102 --- /dev/null +++ b/gcc-4.9/gcc/ada/sem_ch10.adb @@ -0,0 +1,6513 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S E M _ C H 1 0 -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 1992-2014, Free Software Foundation, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 3, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- +-- for more details. You should have received a copy of the GNU General -- +-- Public License distributed with GNAT; see file COPYING3. If not, go to -- +-- http://www.gnu.org/licenses for a complete copy of the license. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- -- +------------------------------------------------------------------------------ + +with Aspects; use Aspects; +with Atree; use Atree; +with Debug; use Debug; +with Einfo; use Einfo; +with Errout; use Errout; +with Exp_Util; use Exp_Util; +with Elists; use Elists; +with Fname; use Fname; +with Fname.UF; use Fname.UF; +with Freeze; use Freeze; +with Impunit; use Impunit; +with Inline; use Inline; +with Lib; use Lib; +with Lib.Load; use Lib.Load; +with Lib.Xref; use Lib.Xref; +with Namet; use Namet; +with Nlists; use Nlists; +with Nmake; use Nmake; +with Opt; use Opt; +with Output; use Output; +with Par_SCO; use Par_SCO; +with Restrict; use Restrict; +with Rident; use Rident; +with Rtsfind; use Rtsfind; +with Sem; use Sem; +with Sem_Aux; use Sem_Aux; +with Sem_Ch3; use Sem_Ch3; +with Sem_Ch6; use Sem_Ch6; +with Sem_Ch7; use Sem_Ch7; +with Sem_Ch8; use Sem_Ch8; +with Sem_Dist; use Sem_Dist; +with Sem_Prag; use Sem_Prag; +with Sem_Util; use Sem_Util; +with Sem_Warn; use Sem_Warn; +with Stand; use Stand; +with Sinfo; use Sinfo; +with Sinfo.CN; use Sinfo.CN; +with Sinput; use Sinput; +with Snames; use Snames; +with Style; use Style; +with Stylesw; use Stylesw; +with Tbuild; use Tbuild; +with Uname; use Uname; + +package body Sem_Ch10 is + + ----------------------- + -- Local Subprograms -- + ----------------------- + + procedure Analyze_Context (N : Node_Id); + -- Analyzes items in the context clause of compilation unit + + procedure Build_Limited_Views (N : Node_Id); + -- Build and decorate the list of shadow entities for a package mentioned + -- in a limited_with clause. If the package was not previously analyzed + -- then it also performs a basic decoration of the real entities. This is + -- required in order to avoid passing non-decorated entities to the + -- back-end. Implements Ada 2005 (AI-50217). + + procedure Check_Body_Needed_For_SAL (Unit_Name : Entity_Id); + -- Check whether the source for the body of a compilation unit must be + -- included in a standalone library. + + procedure Check_Private_Child_Unit (N : Node_Id); + -- If a with_clause mentions a private child unit, the compilation unit + -- must be a member of the same family, as described in 10.1.2. + + procedure Check_Stub_Level (N : Node_Id); + -- Verify that a stub is declared immediately within a compilation unit, + -- and not in an inner frame. + + procedure Expand_With_Clause (Item : Node_Id; Nam : Node_Id; N : Node_Id); + -- When a child unit appears in a context clause, the implicit withs on + -- parents are made explicit, and with clauses are inserted in the context + -- clause before the one for the child. If a parent in the with_clause + -- is a renaming, the implicit with_clause is on the renaming whose name + -- is mentioned in the with_clause, and not on the package it renames. + -- N is the compilation unit whose list of context items receives the + -- implicit with_clauses. + + procedure Generate_Parent_References (N : Node_Id; P_Id : Entity_Id); + -- Generate cross-reference information for the parents of child units + -- and of subunits. N is a defining_program_unit_name, and P_Id is the + -- immediate parent scope. + + function Get_Parent_Entity (Unit : Node_Id) return Entity_Id; + -- Get defining entity of parent unit of a child unit. In most cases this + -- is the defining entity of the unit, but for a child instance whose + -- parent needs a body for inlining, the instantiation node of the parent + -- has not yet been rewritten as a package declaration, and the entity has + -- to be retrieved from the Instance_Spec of the unit. + + function Has_With_Clause + (C_Unit : Node_Id; + Pack : Entity_Id; + Is_Limited : Boolean := False) return Boolean; + -- Determine whether compilation unit C_Unit contains a [limited] with + -- clause for package Pack. Use the flag Is_Limited to designate desired + -- clause kind. + + procedure Implicit_With_On_Parent (Child_Unit : Node_Id; N : Node_Id); + -- If the main unit is a child unit, implicit withs are also added for + -- all its ancestors. + + function In_Chain (E : Entity_Id) return Boolean; + -- Check that the shadow entity is not already in the homonym chain, for + -- example through a limited_with clause in a parent unit. + + procedure Install_Context_Clauses (N : Node_Id); + -- Subsidiary to Install_Context and Install_Parents. Process all with + -- and use clauses for current unit and its library unit if any. + + procedure Install_Limited_Context_Clauses (N : Node_Id); + -- Subsidiary to Install_Context. Process only limited with_clauses for + -- current unit. Implements Ada 2005 (AI-50217). + + procedure Install_Limited_Withed_Unit (N : Node_Id); + -- Place shadow entities for a limited_with package in the visibility + -- structures for the current compilation. Implements Ada 2005 (AI-50217). + + procedure Install_Withed_Unit + (With_Clause : Node_Id; + Private_With_OK : Boolean := False); + -- If the unit is not a child unit, make unit immediately visible. The + -- caller ensures that the unit is not already currently installed. The + -- flag Private_With_OK is set true in Install_Private_With_Clauses, which + -- is called when compiling the private part of a package, or installing + -- the private declarations of a parent unit. + + procedure Install_Parents (Lib_Unit : Node_Id; Is_Private : Boolean); + -- This procedure establishes the context for the compilation of a child + -- unit. If Lib_Unit is a child library spec then the context of the parent + -- is installed, and the parent itself made immediately visible, so that + -- the child unit is processed in the declarative region of the parent. + -- Install_Parents makes a recursive call to itself to ensure that all + -- parents are loaded in the nested case. If Lib_Unit is a library body, + -- the only effect of Install_Parents is to install the private decls of + -- the parents, because the visible parent declarations will have been + -- installed as part of the context of the corresponding spec. + + procedure Install_Siblings (U_Name : Entity_Id; N : Node_Id); + -- In the compilation of a child unit, a child of any of the ancestor + -- units is directly visible if it is visible, because the parent is in + -- an enclosing scope. Iterate over context to find child units of U_Name + -- or of some ancestor of it. + + function Is_Ancestor_Unit (U1 : Node_Id; U2 : Node_Id) return Boolean; + -- When compiling a unit Q descended from some parent unit P, a limited + -- with_clause in the context of P that names some other ancestor of Q + -- must not be installed because the ancestor is immediately visible. + + function Is_Child_Spec (Lib_Unit : Node_Id) return Boolean; + -- Lib_Unit is a library unit which may be a spec or a body. Is_Child_Spec + -- returns True if Lib_Unit is a library spec which is a child spec, i.e. + -- a library spec that has a parent. If the call to Is_Child_Spec returns + -- True, then Parent_Spec (Lib_Unit) is non-Empty and points to the + -- compilation unit for the parent spec. + -- + -- Lib_Unit can also be a subprogram body that acts as its own spec. If the + -- Parent_Spec is non-empty, this is also a child unit. + + procedure Remove_Context_Clauses (N : Node_Id); + -- Subsidiary of previous one. Remove use_ and with_clauses + + procedure Remove_Limited_With_Clause (N : Node_Id); + -- Remove from visibility the shadow entities introduced for a package + -- mentioned in a limited_with clause. Implements Ada 2005 (AI-50217). + + procedure Remove_Parents (Lib_Unit : Node_Id); + -- Remove_Parents checks if Lib_Unit is a child spec. If so then the parent + -- contexts established by the corresponding call to Install_Parents are + -- removed. Remove_Parents contains a recursive call to itself to ensure + -- that all parents are removed in the nested case. + + procedure Remove_Unit_From_Visibility (Unit_Name : Entity_Id); + -- Reset all visibility flags on unit after compiling it, either as a main + -- unit or as a unit in the context. + + procedure Unchain (E : Entity_Id); + -- Remove single entity from visibility list + + procedure Analyze_Proper_Body (N : Node_Id; Nam : Entity_Id); + -- Common processing for all stubs (subprograms, tasks, packages, and + -- protected cases). N is the stub to be analyzed. Once the subunit name + -- is established, load and analyze. Nam is the non-overloadable entity + -- for which the proper body provides a completion. Subprogram stubs are + -- handled differently because they can be declarations. + + procedure sm; + -- A dummy procedure, for debugging use, called just before analyzing the + -- main unit (after dealing with any context clauses). + + -------------------------- + -- Limited_With_Clauses -- + -------------------------- + + -- Limited_With clauses are the mechanism chosen for Ada 2005 to support + -- mutually recursive types declared in different units. A limited_with + -- clause that names package P in the context of unit U makes the types + -- declared in the visible part of P available within U, but with the + -- restriction that these types can only be used as incomplete types. + -- The limited_with clause does not impose a semantic dependence on P, + -- and it is possible for two packages to have limited_with_clauses on + -- each other without creating an elaboration circularity. + + -- To support this feature, the analysis of a limited_with clause must + -- create an abbreviated view of the package, without performing any + -- semantic analysis on it. This "package abstract" contains shadow types + -- that are in one-one correspondence with the real types in the package, + -- and that have the properties of incomplete types. + + -- The implementation creates two element lists: one to chain the shadow + -- entities, and one to chain the corresponding type entities in the tree + -- of the package. Links between corresponding entities in both chains + -- allow the compiler to select the proper view of a given type, depending + -- on the context. Note that in contrast with the handling of private + -- types, the limited view and the non-limited view of a type are treated + -- as separate entities, and no entity exchange needs to take place, which + -- makes the implementation must simpler than could be feared. + + ------------------------------ + -- Analyze_Compilation_Unit -- + ------------------------------ + + procedure Analyze_Compilation_Unit (N : Node_Id) is + Unit_Node : constant Node_Id := Unit (N); + Lib_Unit : Node_Id := Library_Unit (N); + Spec_Id : Entity_Id; + Main_Cunit : constant Node_Id := Cunit (Main_Unit); + Par_Spec_Name : Unit_Name_Type; + Unum : Unit_Number_Type; + + procedure Check_Redundant_Withs + (Context_Items : List_Id; + Spec_Context_Items : List_Id := No_List); + -- Determine whether the context list of a compilation unit contains + -- redundant with clauses. When checking body clauses against spec + -- clauses, set Context_Items to the context list of the body and + -- Spec_Context_Items to that of the spec. Parent packages are not + -- examined for documentation purposes. + + --------------------------- + -- Check_Redundant_Withs -- + --------------------------- + + procedure Check_Redundant_Withs + (Context_Items : List_Id; + Spec_Context_Items : List_Id := No_List) + is + Clause : Node_Id; + + procedure Process_Body_Clauses + (Context_List : List_Id; + Clause : Node_Id; + Used : in out Boolean; + Used_Type_Or_Elab : in out Boolean); + -- Examine the context clauses of a package body, trying to match the + -- name entity of Clause with any list element. If the match occurs + -- on a use package clause set Used to True, for a use type clause or + -- pragma Elaborate[_All], set Used_Type_Or_Elab to True. + + procedure Process_Spec_Clauses + (Context_List : List_Id; + Clause : Node_Id; + Used : in out Boolean; + Withed : in out Boolean; + Exit_On_Self : Boolean := False); + -- Examine the context clauses of a package spec, trying to match + -- the name entity of Clause with any list element. If the match + -- occurs on a use package clause, set Used to True, for a with + -- package clause other than Clause, set Withed to True. Limited + -- with clauses, implicitly generated with clauses and withs + -- having pragmas Elaborate or Elaborate_All applied to them are + -- skipped. Exit_On_Self is used to control the search loop and + -- force an exit whenever Clause sees itself in the search. + + -------------------------- + -- Process_Body_Clauses -- + -------------------------- + + procedure Process_Body_Clauses + (Context_List : List_Id; + Clause : Node_Id; + Used : in out Boolean; + Used_Type_Or_Elab : in out Boolean) + is + Nam_Ent : constant Entity_Id := Entity (Name (Clause)); + Cont_Item : Node_Id; + Prag_Unit : Node_Id; + Subt_Mark : Node_Id; + Use_Item : Node_Id; + + function Same_Unit (N : Node_Id; P : Entity_Id) return Boolean; + -- In an expanded name in a use clause, if the prefix is a renamed + -- package, the entity is set to the original package as a result, + -- when checking whether the package appears in a previous with + -- clause, the renaming has to be taken into account, to prevent + -- spurious/incorrect warnings. A common case is use of Text_IO. + + --------------- + -- Same_Unit -- + --------------- + + function Same_Unit (N : Node_Id; P : Entity_Id) return Boolean is + begin + return Entity (N) = P + or else (Present (Renamed_Object (P)) + and then Entity (N) = Renamed_Object (P)); + end Same_Unit; + + -- Start of processing for Process_Body_Clauses + + begin + Used := False; + Used_Type_Or_Elab := False; + + Cont_Item := First (Context_List); + while Present (Cont_Item) loop + + -- Package use clause + + if Nkind (Cont_Item) = N_Use_Package_Clause + and then not Used + then + -- Search through use clauses + + Use_Item := First (Names (Cont_Item)); + while Present (Use_Item) and then not Used loop + + -- Case of a direct use of the one we are looking for + + if Entity (Use_Item) = Nam_Ent then + Used := True; + + -- Handle nested case, as in "with P; use P.Q.R" + + else + declare + UE : Node_Id; + + begin + -- Loop through prefixes looking for match + + UE := Use_Item; + while Nkind (UE) = N_Expanded_Name loop + if Same_Unit (Prefix (UE), Nam_Ent) then + Used := True; + exit; + end if; + + UE := Prefix (UE); + end loop; + end; + end if; + + Next (Use_Item); + end loop; + + -- USE TYPE clause + + elsif Nkind (Cont_Item) = N_Use_Type_Clause + and then not Used_Type_Or_Elab + then + Subt_Mark := First (Subtype_Marks (Cont_Item)); + while Present (Subt_Mark) + and then not Used_Type_Or_Elab + loop + if Same_Unit (Prefix (Subt_Mark), Nam_Ent) then + Used_Type_Or_Elab := True; + end if; + + Next (Subt_Mark); + end loop; + + -- Pragma Elaborate or Elaborate_All + + elsif Nkind (Cont_Item) = N_Pragma + and then + Nam_In (Pragma_Name (Cont_Item), Name_Elaborate, + Name_Elaborate_All) + and then not Used_Type_Or_Elab + then + Prag_Unit := + First (Pragma_Argument_Associations (Cont_Item)); + while Present (Prag_Unit) and then not Used_Type_Or_Elab loop + if Entity (Expression (Prag_Unit)) = Nam_Ent then + Used_Type_Or_Elab := True; + end if; + + Next (Prag_Unit); + end loop; + end if; + + Next (Cont_Item); + end loop; + end Process_Body_Clauses; + + -------------------------- + -- Process_Spec_Clauses -- + -------------------------- + + procedure Process_Spec_Clauses + (Context_List : List_Id; + Clause : Node_Id; + Used : in out Boolean; + Withed : in out Boolean; + Exit_On_Self : Boolean := False) + is + Nam_Ent : constant Entity_Id := Entity (Name (Clause)); + Cont_Item : Node_Id; + Use_Item : Node_Id; + + begin + Used := False; + Withed := False; + + Cont_Item := First (Context_List); + while Present (Cont_Item) loop + + -- Stop the search since the context items after Cont_Item have + -- already been examined in a previous iteration of the reverse + -- loop in Check_Redundant_Withs. + + if Exit_On_Self + and Cont_Item = Clause + then + exit; + end if; + + -- Package use clause + + if Nkind (Cont_Item) = N_Use_Package_Clause + and then not Used + then + Use_Item := First (Names (Cont_Item)); + while Present (Use_Item) and then not Used loop + if Entity (Use_Item) = Nam_Ent then + Used := True; + end if; + + Next (Use_Item); + end loop; + + -- Package with clause. Avoid processing self, implicitly + -- generated with clauses or limited with clauses. Note that + -- we examine with clauses having pragmas Elaborate or + -- Elaborate_All applied to them due to cases such as: + + -- with Pack; + -- with Pack; + -- pragma Elaborate (Pack); + + -- In this case, the second with clause is redundant since + -- the pragma applies only to the first "with Pack;". + + -- Note that we only consider with_clauses that comes from + -- source. In the case of renamings used as prefixes of names + -- in with_clauses, we generate a with_clause for the prefix, + -- which we do not treat as implicit because it is needed for + -- visibility analysis, but is also not redundant. + + elsif Nkind (Cont_Item) = N_With_Clause + and then not Implicit_With (Cont_Item) + and then Comes_From_Source (Cont_Item) + and then not Limited_Present (Cont_Item) + and then Cont_Item /= Clause + and then Entity (Name (Cont_Item)) = Nam_Ent + then + Withed := True; + end if; + + Next (Cont_Item); + end loop; + end Process_Spec_Clauses; + + -- Start of processing for Check_Redundant_Withs + + begin + Clause := Last (Context_Items); + while Present (Clause) loop + + -- Avoid checking implicitly generated with clauses, limited with + -- clauses or withs that have pragma Elaborate or Elaborate_All. + + if Nkind (Clause) = N_With_Clause + and then not Implicit_With (Clause) + and then not Limited_Present (Clause) + and then not Elaborate_Present (Clause) + then + -- Package body-to-spec check + + if Present (Spec_Context_Items) then + declare + Used_In_Body : Boolean := False; + Used_In_Spec : Boolean := False; + Used_Type_Or_Elab : Boolean := False; + Withed_In_Spec : Boolean := False; + + begin + Process_Spec_Clauses + (Context_List => Spec_Context_Items, + Clause => Clause, + Used => Used_In_Spec, + Withed => Withed_In_Spec); + + Process_Body_Clauses + (Context_List => Context_Items, + Clause => Clause, + Used => Used_In_Body, + Used_Type_Or_Elab => Used_Type_Or_Elab); + + -- "Type Elab" refers to the presence of either a use + -- type clause, pragmas Elaborate or Elaborate_All. + + -- +---------------+---------------------------+------+ + -- | Spec | Body | Warn | + -- +--------+------+--------+------+-----------+------+ + -- | Withed | Used | Withed | Used | Type Elab | | + -- | X | | X | | | X | + -- | X | | X | X | | | + -- | X | | X | | X | | + -- | X | | X | X | X | | + -- | X | X | X | | | X | + -- | X | X | X | | X | | + -- | X | X | X | X | | X | + -- | X | X | X | X | X | | + -- +--------+------+--------+------+-----------+------+ + + if (Withed_In_Spec + and then not Used_Type_Or_Elab) + and then + ((not Used_In_Spec and then not Used_In_Body) + or else Used_In_Spec) + then + Error_Msg_N -- CODEFIX + ("redundant with clause in body??", Clause); + end if; + + Used_In_Body := False; + Used_In_Spec := False; + Used_Type_Or_Elab := False; + Withed_In_Spec := False; + end; + + -- Standalone package spec or body check + + else + declare + Dont_Care : Boolean := False; + Withed : Boolean := False; + + begin + -- The mechanism for examining the context clauses of a + -- package spec can be applied to package body clauses. + + Process_Spec_Clauses + (Context_List => Context_Items, + Clause => Clause, + Used => Dont_Care, + Withed => Withed, + Exit_On_Self => True); + + if Withed then + Error_Msg_N -- CODEFIX + ("redundant with clause??", Clause); + end if; + end; + end if; + end if; + + Prev (Clause); + end loop; + end Check_Redundant_Withs; + + -- Start of processing for Analyze_Compilation_Unit + + begin + Process_Compilation_Unit_Pragmas (N); + + -- If the unit is a subunit whose parent has not been analyzed (which + -- indicates that the main unit is a subunit, either the current one or + -- one of its descendents) then the subunit is compiled as part of the + -- analysis of the parent, which we proceed to do. Basically this gets + -- handled from the top down and we don't want to do anything at this + -- level (i.e. this subunit will be handled on the way down from the + -- parent), so at this level we immediately return. If the subunit ends + -- up not analyzed, it means that the parent did not contain a stub for + -- it, or that there errors were detected in some ancestor. + + if Nkind (Unit_Node) = N_Subunit and then not Analyzed (Lib_Unit) then + Semantics (Lib_Unit); + + if not Analyzed (Proper_Body (Unit_Node)) then + if Serious_Errors_Detected > 0 then + Error_Msg_N ("subunit not analyzed (errors in parent unit)", N); + else + Error_Msg_N ("missing stub for subunit", N); + end if; + end if; + + return; + end if; + + -- Analyze context (this will call Sem recursively for with'ed units) To + -- detect circularities among with-clauses that are not caught during + -- loading, we set the Context_Pending flag on the current unit. If the + -- flag is already set there is a potential circularity. We exclude + -- predefined units from this check because they are known to be safe. + -- We also exclude package bodies that are present because circularities + -- between bodies are harmless (and necessary). + + if Context_Pending (N) then + declare + Circularity : Boolean := True; + + begin + if Is_Predefined_File_Name + (Unit_File_Name (Get_Source_Unit (Unit (N)))) + then + Circularity := False; + + else + for U in Main_Unit + 1 .. Last_Unit loop + if Nkind (Unit (Cunit (U))) = N_Package_Body + and then not Analyzed (Cunit (U)) + then + Circularity := False; + exit; + end if; + end loop; + end if; + + if Circularity then + Error_Msg_N ("circular dependency caused by with_clauses", N); + Error_Msg_N + ("\possibly missing limited_with clause" + & " in one of the following", N); + + for U in Main_Unit .. Last_Unit loop + if Context_Pending (Cunit (U)) then + Error_Msg_Unit_1 := Get_Unit_Name (Unit (Cunit (U))); + Error_Msg_N ("\unit$", N); + end if; + end loop; + + raise Unrecoverable_Error; + end if; + end; + else + Set_Context_Pending (N); + end if; + + Analyze_Context (N); + + Set_Context_Pending (N, False); + + -- If the unit is a package body, the spec is already loaded and must be + -- analyzed first, before we analyze the body. + + if Nkind (Unit_Node) = N_Package_Body then + + -- If no Lib_Unit, then there was a serious previous error, so just + -- ignore the entire analysis effort + + if No (Lib_Unit) then + Check_Error_Detected; + return; + + else + -- Analyze the package spec + + Semantics (Lib_Unit); + + -- Check for unused with's + + Check_Unused_Withs (Get_Cunit_Unit_Number (Lib_Unit)); + + -- Verify that the library unit is a package declaration + + if not Nkind_In (Unit (Lib_Unit), N_Package_Declaration, + N_Generic_Package_Declaration) + then + Error_Msg_N + ("no legal package declaration for package body", N); + return; + + -- Otherwise, the entity in the declaration is visible. Update the + -- version to reflect dependence of this body on the spec. + + else + Spec_Id := Defining_Entity (Unit (Lib_Unit)); + Set_Is_Immediately_Visible (Spec_Id, True); + Version_Update (N, Lib_Unit); + + if Nkind (Defining_Unit_Name (Unit_Node)) = + N_Defining_Program_Unit_Name + then + Generate_Parent_References (Unit_Node, Scope (Spec_Id)); + end if; + end if; + end if; + + -- If the unit is a subprogram body, then we similarly need to analyze + -- its spec. However, things are a little simpler in this case, because + -- here, this analysis is done mostly for error checking and consistency + -- purposes (but not only, e.g. there could be a contract on the spec), + -- so there's nothing else to be done. + + elsif Nkind (Unit_Node) = N_Subprogram_Body then + if Acts_As_Spec (N) then + + -- If the subprogram body is a child unit, we must create a + -- declaration for it, in order to properly load the parent(s). + -- After this, the original unit does not acts as a spec, because + -- there is an explicit one. If this unit appears in a context + -- clause, then an implicit with on the parent will be added when + -- installing the context. If this is the main unit, there is no + -- Unit_Table entry for the declaration (it has the unit number + -- of the main unit) and code generation is unaffected. + + Unum := Get_Cunit_Unit_Number (N); + Par_Spec_Name := Get_Parent_Spec_Name (Unit_Name (Unum)); + + if Par_Spec_Name /= No_Unit_Name then + Unum := + Load_Unit + (Load_Name => Par_Spec_Name, + Required => True, + Subunit => False, + Error_Node => N); + + if Unum /= No_Unit then + + -- Build subprogram declaration and attach parent unit to it + -- This subprogram declaration does not come from source, + -- Nevertheless the backend must generate debugging info for + -- it, and this must be indicated explicitly. We also mark + -- the body entity as a child unit now, to prevent a + -- cascaded error if the spec entity cannot be entered + -- in its scope. Finally we create a Units table entry for + -- the subprogram declaration, to maintain a one-to-one + -- correspondence with compilation unit nodes. This is + -- critical for the tree traversals performed by CodePeer. + + declare + Loc : constant Source_Ptr := Sloc (N); + SCS : constant Boolean := + Get_Comes_From_Source_Default; + + begin + Set_Comes_From_Source_Default (False); + + -- Checks for redundant USE TYPE clauses have a special + -- exception for the synthetic spec we create here. This + -- special case relies on the two compilation units + -- sharing the same context clause. + + -- Note: We used to do a shallow copy (New_Copy_List), + -- which defeated those checks and also created malformed + -- trees (subtype mark shared by two distinct + -- N_Use_Type_Clause nodes) which crashed the compiler. + + Lib_Unit := + Make_Compilation_Unit (Loc, + Context_Items => Context_Items (N), + Unit => + Make_Subprogram_Declaration (Sloc (N), + Specification => + Copy_Separate_Tree + (Specification (Unit_Node))), + Aux_Decls_Node => + Make_Compilation_Unit_Aux (Loc)); + + Set_Library_Unit (N, Lib_Unit); + Set_Parent_Spec (Unit (Lib_Unit), Cunit (Unum)); + Make_Child_Decl_Unit (N); + Semantics (Lib_Unit); + + -- Now that a separate declaration exists, the body + -- of the child unit does not act as spec any longer. + + Set_Acts_As_Spec (N, False); + Set_Is_Child_Unit (Defining_Entity (Unit_Node)); + Set_Debug_Info_Needed (Defining_Entity (Unit (Lib_Unit))); + Set_Comes_From_Source_Default (SCS); + end; + end if; + end if; + + -- Here for subprogram with separate declaration + + else + Semantics (Lib_Unit); + Check_Unused_Withs (Get_Cunit_Unit_Number (Lib_Unit)); + Version_Update (N, Lib_Unit); + end if; + + -- If this is a child unit, generate references to the parents + + if Nkind (Defining_Unit_Name (Specification (Unit_Node))) = + N_Defining_Program_Unit_Name + then + Generate_Parent_References + (Specification (Unit_Node), + Scope (Defining_Entity (Unit (Lib_Unit)))); + end if; + end if; + + -- If it is a child unit, the parent must be elaborated first and we + -- update version, since we are dependent on our parent. + + if Is_Child_Spec (Unit_Node) then + + -- The analysis of the parent is done with style checks off + + declare + Save_Style_Check : constant Boolean := Style_Check; + + begin + if not GNAT_Mode then + Style_Check := False; + end if; + + Semantics (Parent_Spec (Unit_Node)); + Version_Update (N, Parent_Spec (Unit_Node)); + + -- Restore style check settings + + Style_Check := Save_Style_Check; + end; + end if; + + -- With the analysis done, install the context. Note that we can't + -- install the context from the with clauses as we analyze them, because + -- each with clause must be analyzed in a clean visibility context, so + -- we have to wait and install them all at once. + + Install_Context (N); + + if Is_Child_Spec (Unit_Node) then + + -- Set the entities of all parents in the program_unit_name + + Generate_Parent_References + (Unit_Node, Get_Parent_Entity (Unit (Parent_Spec (Unit_Node)))); + end if; + + -- All components of the context: with-clauses, library unit, ancestors + -- if any, (and their context) are analyzed and installed. + + -- Call special debug routine sm if this is the main unit + + if Current_Sem_Unit = Main_Unit then + sm; + end if; + + -- Now analyze the unit (package, subprogram spec, body) itself + + Analyze (Unit_Node); + + if Warn_On_Redundant_Constructs then + Check_Redundant_Withs (Context_Items (N)); + + if Nkind (Unit_Node) = N_Package_Body then + Check_Redundant_Withs + (Context_Items => Context_Items (N), + Spec_Context_Items => Context_Items (Lib_Unit)); + end if; + end if; + + -- The above call might have made Unit_Node an N_Subprogram_Body from + -- something else, so propagate any Acts_As_Spec flag. + + if Nkind (Unit_Node) = N_Subprogram_Body + and then Acts_As_Spec (Unit_Node) + then + Set_Acts_As_Spec (N); + end if; + + -- Register predefined units in Rtsfind + + declare + Unum : constant Unit_Number_Type := Get_Source_Unit (Sloc (N)); + begin + if Is_Predefined_File_Name (Unit_File_Name (Unum)) then + Set_RTU_Loaded (Unit_Node); + end if; + end; + + -- Treat compilation unit pragmas that appear after the library unit + + if Present (Pragmas_After (Aux_Decls_Node (N))) then + declare + Prag_Node : Node_Id := First (Pragmas_After (Aux_Decls_Node (N))); + begin + while Present (Prag_Node) loop + Analyze (Prag_Node); + Next (Prag_Node); + end loop; + end; + end if; + + -- Generate distribution stubs if requested and no error + + if N = Main_Cunit + and then (Distribution_Stub_Mode = Generate_Receiver_Stub_Body + or else + Distribution_Stub_Mode = Generate_Caller_Stub_Body) + and then not Fatal_Error (Main_Unit) + then + if Is_RCI_Pkg_Spec_Or_Body (N) then + + -- Regular RCI package + + Add_Stub_Constructs (N); + + elsif (Nkind (Unit_Node) = N_Package_Declaration + and then Is_Shared_Passive (Defining_Entity + (Specification (Unit_Node)))) + or else (Nkind (Unit_Node) = N_Package_Body + and then + Is_Shared_Passive (Corresponding_Spec (Unit_Node))) + then + -- Shared passive package + + Add_Stub_Constructs (N); + + elsif Nkind (Unit_Node) = N_Package_Instantiation + and then + Is_Remote_Call_Interface + (Defining_Entity (Specification (Instance_Spec (Unit_Node)))) + then + -- Instantiation of a RCI generic package + + Add_Stub_Constructs (N); + end if; + end if; + + -- Remove unit from visibility, so that environment is clean for the + -- next compilation, which is either the main unit or some other unit + -- in the context. + + if Nkind_In (Unit_Node, N_Package_Declaration, + N_Package_Renaming_Declaration, + N_Subprogram_Declaration) + or else Nkind (Unit_Node) in N_Generic_Declaration + or else (Nkind (Unit_Node) = N_Subprogram_Body + and then Acts_As_Spec (Unit_Node)) + then + Remove_Unit_From_Visibility (Defining_Entity (Unit_Node)); + + -- If the unit is an instantiation whose body will be elaborated for + -- inlining purposes, use the proper entity of the instance. The entity + -- may be missing if the instantiation was illegal. + + elsif Nkind (Unit_Node) = N_Package_Instantiation + and then not Error_Posted (Unit_Node) + and then Present (Instance_Spec (Unit_Node)) + then + Remove_Unit_From_Visibility + (Defining_Entity (Instance_Spec (Unit_Node))); + + elsif Nkind (Unit_Node) = N_Package_Body + or else (Nkind (Unit_Node) = N_Subprogram_Body + and then not Acts_As_Spec (Unit_Node)) + then + -- Bodies that are not the main unit are compiled if they are generic + -- or contain generic or inlined units. Their analysis brings in the + -- context of the corresponding spec (unit declaration) which must be + -- removed as well, to return the compilation environment to its + -- proper state. + + Remove_Context (Lib_Unit); + Set_Is_Immediately_Visible (Defining_Entity (Unit (Lib_Unit)), False); + end if; + + -- Last step is to deinstall the context we just installed as well as + -- the unit just compiled. + + Remove_Context (N); + + -- If this is the main unit and we are generating code, we must check + -- that all generic units in the context have a body if they need it, + -- even if they have not been instantiated. In the absence of .ali files + -- for generic units, we must force the load of the body, just to + -- produce the proper error if the body is absent. We skip this + -- verification if the main unit itself is generic. + + if Get_Cunit_Unit_Number (N) = Main_Unit + and then Operating_Mode = Generate_Code + and then Expander_Active + then + -- Check whether the source for the body of the unit must be included + -- in a standalone library. + + Check_Body_Needed_For_SAL (Cunit_Entity (Main_Unit)); + + -- Indicate that the main unit is now analyzed, to catch possible + -- circularities between it and generic bodies. Remove main unit from + -- visibility. This might seem superfluous, but the main unit must + -- not be visible in the generic body expansions that follow. + + Set_Analyzed (N, True); + Set_Is_Immediately_Visible (Cunit_Entity (Main_Unit), False); + + declare + Item : Node_Id; + Nam : Entity_Id; + Un : Unit_Number_Type; + + Save_Style_Check : constant Boolean := Style_Check; + + begin + Item := First (Context_Items (N)); + while Present (Item) loop + + -- Check for explicit with clause + + if Nkind (Item) = N_With_Clause + and then not Implicit_With (Item) + + -- Ada 2005 (AI-50217): Ignore limited-withed units + + and then not Limited_Present (Item) + then + Nam := Entity (Name (Item)); + + -- Compile generic subprogram, unless it is intrinsic or + -- imported so no body is required, or generic package body + -- if the package spec requires a body. + + if (Is_Generic_Subprogram (Nam) + and then not Is_Intrinsic_Subprogram (Nam) + and then not Is_Imported (Nam)) + or else (Ekind (Nam) = E_Generic_Package + and then Unit_Requires_Body (Nam)) + then + Style_Check := False; + + if Present (Renamed_Object (Nam)) then + Un := + Load_Unit + (Load_Name => Get_Body_Name + (Get_Unit_Name + (Unit_Declaration_Node + (Renamed_Object (Nam)))), + Required => False, + Subunit => False, + Error_Node => N, + Renamings => True); + else + Un := + Load_Unit + (Load_Name => Get_Body_Name + (Get_Unit_Name (Item)), + Required => False, + Subunit => False, + Error_Node => N, + Renamings => True); + end if; + + if Un = No_Unit then + Error_Msg_NE + ("body of generic unit& not found", Item, Nam); + exit; + + elsif not Analyzed (Cunit (Un)) + and then Un /= Main_Unit + and then not Fatal_Error (Un) + then + Style_Check := False; + Semantics (Cunit (Un)); + end if; + end if; + end if; + + Next (Item); + end loop; + + -- Restore style checks settings + + Style_Check := Save_Style_Check; + end; + end if; + + -- Deal with creating elaboration counter if needed. We create an + -- elaboration counter only for units that come from source since + -- units manufactured by the compiler never need elab checks. + + if Comes_From_Source (N) + and then Nkind_In (Unit_Node, N_Package_Declaration, + N_Generic_Package_Declaration, + N_Subprogram_Declaration, + N_Generic_Subprogram_Declaration) + then + declare + Loc : constant Source_Ptr := Sloc (N); + Unum : constant Unit_Number_Type := Get_Source_Unit (Loc); + + begin + Spec_Id := Defining_Entity (Unit_Node); + Generate_Definition (Spec_Id); + + -- See if an elaboration entity is required for possible access + -- before elaboration checking. Note that we must allow for this + -- even if -gnatE is not set, since a client may be compiled in + -- -gnatE mode and reference the entity. + + -- These entities are also used by the binder to prevent multiple + -- attempts to execute the elaboration code for the library case + -- where the elaboration routine might otherwise be called more + -- than once. + + -- Case of units which do not require elaboration checks + + if + -- Pure units do not need checks + + Is_Pure (Spec_Id) + + -- Preelaborated units do not need checks + + or else Is_Preelaborated (Spec_Id) + + -- No checks needed if pragma Elaborate_Body present + + or else Has_Pragma_Elaborate_Body (Spec_Id) + + -- No checks needed if unit does not require a body + + or else not Unit_Requires_Body (Spec_Id) + + -- No checks needed for predefined files + + or else Is_Predefined_File_Name (Unit_File_Name (Unum)) + + -- No checks required if no separate spec + + or else Acts_As_Spec (N) + then + -- This is a case where we only need the entity for + -- checking to prevent multiple elaboration checks. + + Set_Elaboration_Entity_Required (Spec_Id, False); + + -- Case of elaboration entity is required for access before + -- elaboration checking (so certainly we must build it). + + else + Set_Elaboration_Entity_Required (Spec_Id, True); + end if; + + Build_Elaboration_Entity (N, Spec_Id); + end; + end if; + + -- Freeze the compilation unit entity. This for sure is needed because + -- of some warnings that can be output (see Freeze_Subprogram), but may + -- in general be required. If freezing actions result, place them in the + -- compilation unit actions list, and analyze them. + + declare + L : constant List_Id := + Freeze_Entity (Cunit_Entity (Current_Sem_Unit), N); + begin + while Is_Non_Empty_List (L) loop + Insert_Library_Level_Action (Remove_Head (L)); + end loop; + end; + + Set_Analyzed (N); + + if Nkind (Unit_Node) = N_Package_Declaration + and then Get_Cunit_Unit_Number (N) /= Main_Unit + and then Expander_Active + then + declare + Save_Style_Check : constant Boolean := Style_Check; + Save_Warning : constant Warning_Mode_Type := Warning_Mode; + Options : Style_Check_Options; + + begin + Save_Style_Check_Options (Options); + Reset_Style_Check_Options; + Opt.Warning_Mode := Suppress; + Check_Body_For_Inlining (N, Defining_Entity (Unit_Node)); + + Reset_Style_Check_Options; + Set_Style_Check_Options (Options); + Style_Check := Save_Style_Check; + Warning_Mode := Save_Warning; + end; + end if; + + -- If we are generating obsolescent warnings, then here is where we + -- generate them for the with'ed items. The reason for this special + -- processing is that the normal mechanism of generating the warnings + -- for referenced entities does not work for context clause references. + -- That's because when we first analyze the context, it is too early to + -- know if the with'ing unit is itself obsolescent (which suppresses + -- the warnings). + + if not GNAT_Mode + and then Warn_On_Obsolescent_Feature + and then Nkind (Unit_Node) not in N_Generic_Instantiation + then + -- Push current compilation unit as scope, so that the test for + -- being within an obsolescent unit will work correctly. The check + -- is not performed within an instantiation, because the warning + -- will have been emitted in the corresponding generic unit. + + Push_Scope (Defining_Entity (Unit_Node)); + + -- Loop through context items to deal with with clauses + + declare + Item : Node_Id; + Nam : Node_Id; + Ent : Entity_Id; + + begin + Item := First (Context_Items (N)); + while Present (Item) loop + if Nkind (Item) = N_With_Clause + + -- Suppress this check in limited-withed units. Further work + -- needed here if we decide to incorporate this check on + -- limited-withed units. + + and then not Limited_Present (Item) + then + Nam := Name (Item); + Ent := Entity (Nam); + + if Is_Obsolescent (Ent) then + Output_Obsolescent_Entity_Warnings (Nam, Ent); + end if; + end if; + + Next (Item); + end loop; + end; + + -- Remove temporary install of current unit as scope + + Pop_Scope; + end if; + end Analyze_Compilation_Unit; + + --------------------- + -- Analyze_Context -- + --------------------- + + procedure Analyze_Context (N : Node_Id) is + Ukind : constant Node_Kind := Nkind (Unit (N)); + Item : Node_Id; + + begin + -- First process all configuration pragmas at the start of the context + -- items. Strictly these are not part of the context clause, but that + -- is where the parser puts them. In any case for sure we must analyze + -- these before analyzing the actual context items, since they can have + -- an effect on that analysis (e.g. pragma Ada_2005 may allow a unit to + -- be with'ed as a result of changing categorizations in Ada 2005). + + Item := First (Context_Items (N)); + while Present (Item) + and then Nkind (Item) = N_Pragma + and then Pragma_Name (Item) in Configuration_Pragma_Names + loop + Analyze (Item); + Next (Item); + end loop; + + -- This is the point at which we capture the configuration settings + -- for the unit. At the moment only the Optimize_Alignment setting + -- needs to be captured. Probably more later ??? + + if Optimize_Alignment_Local then + Set_OA_Setting (Current_Sem_Unit, 'L'); + else + Set_OA_Setting (Current_Sem_Unit, Optimize_Alignment); + end if; + + -- Loop through actual context items. This is done in two passes: + + -- a) The first pass analyzes non-limited with-clauses and also any + -- configuration pragmas (we need to get the latter analyzed right + -- away, since they can affect processing of subsequent items. + + -- b) The second pass analyzes limited_with clauses (Ada 2005: AI-50217) + + while Present (Item) loop + + -- For with clause, analyze the with clause, and then update the + -- version, since we are dependent on a unit that we with. + + if Nkind (Item) = N_With_Clause + and then not Limited_Present (Item) + then + -- Skip analyzing with clause if no unit, nothing to do (this + -- happens for a with that references a non-existent unit). Skip + -- as well if this is a with_clause for the main unit, which + -- happens if a subunit has a useless with_clause on its parent. + + if Present (Library_Unit (Item)) then + if Library_Unit (Item) /= Cunit (Current_Sem_Unit) then + Analyze (Item); + + else + Set_Entity (Name (Item), Cunit_Entity (Current_Sem_Unit)); + end if; + end if; + + if not Implicit_With (Item) then + Version_Update (N, Library_Unit (Item)); + end if; + + -- Skip pragmas. Configuration pragmas at the start were handled in + -- the loop above, and remaining pragmas are not processed until we + -- actually install the context (see Install_Context). We delay the + -- analysis of these pragmas to make sure that we have installed all + -- the implicit with's on parent units. + + -- Skip use clauses at this stage, since we don't want to do any + -- installing of potentially use-visible entities until we + -- actually install the complete context (in Install_Context). + -- Otherwise things can get installed in the wrong context. + + else + null; + end if; + + Next (Item); + end loop; + + -- Second pass: examine all limited_with clauses. All other context + -- items are ignored in this pass. + + Item := First (Context_Items (N)); + while Present (Item) loop + if Nkind (Item) = N_With_Clause + and then Limited_Present (Item) + then + -- No need to check errors on implicitly generated limited-with + -- clauses. + + if not Implicit_With (Item) then + + -- Verify that the illegal contexts given in 10.1.2 (18/2) are + -- properly rejected, including renaming declarations. + + if not Nkind_In (Ukind, N_Package_Declaration, + N_Subprogram_Declaration) + and then Ukind not in N_Generic_Declaration + and then Ukind not in N_Generic_Instantiation + then + Error_Msg_N ("limited with_clause not allowed here", Item); + + -- Check wrong use of a limited with clause applied to the + -- compilation unit containing the limited-with clause. + + -- limited with P.Q; + -- package P.Q is ... + + elsif Unit (Library_Unit (Item)) = Unit (N) then + Error_Msg_N ("wrong use of limited-with clause", Item); + + -- Check wrong use of limited-with clause applied to some + -- immediate ancestor. + + elsif Is_Child_Spec (Unit (N)) then + declare + Lib_U : constant Entity_Id := Unit (Library_Unit (Item)); + P : Node_Id; + + begin + P := Parent_Spec (Unit (N)); + loop + if Unit (P) = Lib_U then + Error_Msg_N ("limited with_clause cannot " + & "name ancestor", Item); + exit; + end if; + + exit when not Is_Child_Spec (Unit (P)); + P := Parent_Spec (Unit (P)); + end loop; + end; + end if; + + -- Check if the limited-withed unit is already visible through + -- some context clause of the current compilation unit or some + -- ancestor of the current compilation unit. + + declare + Lim_Unit_Name : constant Node_Id := Name (Item); + Comp_Unit : Node_Id; + It : Node_Id; + Unit_Name : Node_Id; + + begin + Comp_Unit := N; + loop + It := First (Context_Items (Comp_Unit)); + while Present (It) loop + if Item /= It + and then Nkind (It) = N_With_Clause + and then not Limited_Present (It) + and then + Nkind_In (Unit (Library_Unit (It)), + N_Package_Declaration, + N_Package_Renaming_Declaration) + then + if Nkind (Unit (Library_Unit (It))) = + N_Package_Declaration + then + Unit_Name := Name (It); + else + Unit_Name := Name (Unit (Library_Unit (It))); + end if; + + -- Check if the named package (or some ancestor) + -- leaves visible the full-view of the unit given + -- in the limited-with clause + + loop + if Designate_Same_Unit (Lim_Unit_Name, + Unit_Name) + then + Error_Msg_Sloc := Sloc (It); + Error_Msg_N + ("simultaneous visibility of limited " + & "and unlimited views not allowed", + Item); + Error_Msg_NE + ("\unlimited view visible through " + & "context clause #", + Item, It); + exit; + + elsif Nkind (Unit_Name) = N_Identifier then + exit; + end if; + + Unit_Name := Prefix (Unit_Name); + end loop; + end if; + + Next (It); + end loop; + + exit when not Is_Child_Spec (Unit (Comp_Unit)); + + Comp_Unit := Parent_Spec (Unit (Comp_Unit)); + end loop; + end; + end if; + + -- Skip analyzing with clause if no unit, see above + + if Present (Library_Unit (Item)) then + Analyze (Item); + end if; + + -- A limited_with does not impose an elaboration order, but + -- there is a semantic dependency for recompilation purposes. + + if not Implicit_With (Item) then + Version_Update (N, Library_Unit (Item)); + end if; + + -- Pragmas and use clauses and with clauses other than limited + -- with's are ignored in this pass through the context items. + + else + null; + end if; + + Next (Item); + end loop; + end Analyze_Context; + + ------------------------------- + -- Analyze_Package_Body_Stub -- + ------------------------------- + + procedure Analyze_Package_Body_Stub (N : Node_Id) is + Id : constant Entity_Id := Defining_Identifier (N); + Nam : Entity_Id; + Opts : Config_Switches_Type; + + begin + -- The package declaration must be in the current declarative part + + Check_Stub_Level (N); + Nam := Current_Entity_In_Scope (Id); + + if No (Nam) or else not Is_Package_Or_Generic_Package (Nam) then + Error_Msg_N ("missing specification for package stub", N); + + elsif Has_Completion (Nam) + and then Present (Corresponding_Body (Unit_Declaration_Node (Nam))) + then + Error_Msg_N ("duplicate or redundant stub for package", N); + + else + -- Retain and restore the configuration options of the enclosing + -- context as the proper body may introduce a set of its own. + + Save_Opt_Config_Switches (Opts); + + -- Indicate that the body of the package exists. If we are doing + -- only semantic analysis, the stub stands for the body. If we are + -- generating code, the existence of the body will be confirmed + -- when we load the proper body. + + Set_Has_Completion (Nam); + Set_Scope (Defining_Entity (N), Current_Scope); + Set_Corresponding_Spec_Of_Stub (N, Nam); + Generate_Reference (Nam, Id, 'b'); + Analyze_Proper_Body (N, Nam); + + Restore_Opt_Config_Switches (Opts); + end if; + end Analyze_Package_Body_Stub; + + ------------------------- + -- Analyze_Proper_Body -- + ------------------------- + + procedure Analyze_Proper_Body (N : Node_Id; Nam : Entity_Id) is + Subunit_Name : constant Unit_Name_Type := Get_Unit_Name (N); + + procedure Optional_Subunit; + -- This procedure is called when the main unit is a stub, or when we + -- are not generating code. In such a case, we analyze the subunit if + -- present, which is user-friendly and in fact required for ASIS, but we + -- don't complain if the subunit is missing. In GNATprove_Mode, we issue + -- an error to avoid formal verification of a partial unit. + + ---------------------- + -- Optional_Subunit -- + ---------------------- + + procedure Optional_Subunit is + Comp_Unit : Node_Id; + Unum : Unit_Number_Type; + + begin + -- Try to load subunit, but ignore any errors that occur during the + -- loading of the subunit, by using the special feature in Errout to + -- ignore all errors. Note that Fatal_Error will still be set, so we + -- will be able to check for this case below. + + if not (ASIS_Mode or GNATprove_Mode) then + Ignore_Errors_Enable := Ignore_Errors_Enable + 1; + end if; + + Unum := + Load_Unit + (Load_Name => Subunit_Name, + Required => GNATprove_Mode, + Subunit => True, + Error_Node => N); + + if not (ASIS_Mode or GNATprove_Mode) then + Ignore_Errors_Enable := Ignore_Errors_Enable - 1; + end if; + + -- All done if we successfully loaded the subunit + + if Unum /= No_Unit + and then (not Fatal_Error (Unum) or else Try_Semantics) + then + Comp_Unit := Cunit (Unum); + + -- If the file was empty or seriously mangled, the unit itself may + -- be missing. + + if No (Unit (Comp_Unit)) then + Error_Msg_N + ("subunit does not contain expected proper body", N); + + elsif Nkind (Unit (Comp_Unit)) /= N_Subunit then + Error_Msg_N + ("expected SEPARATE subunit, found child unit", + Cunit_Entity (Unum)); + else + Set_Corresponding_Stub (Unit (Comp_Unit), N); + Analyze_Subunit (Comp_Unit); + Set_Library_Unit (N, Comp_Unit); + end if; + + elsif Unum = No_Unit + and then Present (Nam) + then + if Is_Protected_Type (Nam) then + Set_Corresponding_Body (Parent (Nam), Defining_Identifier (N)); + else + Set_Corresponding_Body ( + Unit_Declaration_Node (Nam), Defining_Identifier (N)); + end if; + end if; + end Optional_Subunit; + + -- Local variables + + Comp_Unit : Node_Id; + Unum : Unit_Number_Type; + + -- Start of processing for Analyze_Proper_Body + + begin + -- If the subunit is already loaded, it means that the main unit is a + -- subunit, and that the current unit is one of its parents which was + -- being analyzed to provide the needed context for the analysis of the + -- subunit. In this case we analyze the subunit and continue with the + -- parent, without looking at subsequent subunits. + + if Is_Loaded (Subunit_Name) then + + -- If the proper body is already linked to the stub node, the stub is + -- in a generic unit and just needs analyzing. + + if Present (Library_Unit (N)) then + Set_Corresponding_Stub (Unit (Library_Unit (N)), N); + + -- If the subunit has severe errors, the spec of the enclosing + -- body may not be available, in which case do not try analysis. + + if Serious_Errors_Detected > 0 + and then No (Library_Unit (Library_Unit (N))) + then + return; + end if; + + Analyze_Subunit (Library_Unit (N)); + + -- Otherwise we must load the subunit and link to it + + else + -- Load the subunit, this must work, since we originally loaded + -- the subunit earlier on. So this will not really load it, just + -- give access to it. + + Unum := + Load_Unit + (Load_Name => Subunit_Name, + Required => True, + Subunit => False, + Error_Node => N); + + -- And analyze the subunit in the parent context (note that we + -- do not call Semantics, since that would remove the parent + -- context). Because of this, we have to manually reset the + -- compiler state to Analyzing since it got destroyed by Load. + + if Unum /= No_Unit then + Compiler_State := Analyzing; + + -- Check that the proper body is a subunit and not a child + -- unit. If the unit was previously loaded, the error will + -- have been emitted when copying the generic node, so we + -- just return to avoid cascaded errors. + + if Nkind (Unit (Cunit (Unum))) /= N_Subunit then + return; + end if; + + Set_Corresponding_Stub (Unit (Cunit (Unum)), N); + Analyze_Subunit (Cunit (Unum)); + Set_Library_Unit (N, Cunit (Unum)); + end if; + end if; + + -- If the main unit is a subunit, then we are just performing semantic + -- analysis on that subunit, and any other subunits of any parent unit + -- should be ignored, except that if we are building trees for ASIS + -- usage we want to annotate the stub properly. + + elsif Nkind (Unit (Cunit (Main_Unit))) = N_Subunit + and then Subunit_Name /= Unit_Name (Main_Unit) + then + if ASIS_Mode then + Optional_Subunit; + end if; + + -- But before we return, set the flag for unloaded subunits. This + -- will suppress junk warnings of variables in the same declarative + -- part (or a higher level one) that are in danger of looking unused + -- when in fact there might be a declaration in the subunit that we + -- do not intend to load. + + Unloaded_Subunits := True; + return; + + -- If the subunit is not already loaded, and we are generating code, + -- then this is the case where compilation started from the parent, and + -- we are generating code for an entire subunit tree. In that case we + -- definitely need to load the subunit. + + -- In order to continue the analysis with the rest of the parent, + -- and other subunits, we load the unit without requiring its + -- presence, and emit a warning if not found, rather than terminating + -- the compilation abruptly, as for other missing file problems. + + elsif Original_Operating_Mode = Generate_Code then + + -- If the proper body is already linked to the stub node, the stub is + -- in a generic unit and just needs analyzing. + + -- We update the version. Although we are not strictly technically + -- semantically dependent on the subunit, given our approach of macro + -- substitution of subunits, it makes sense to include it in the + -- version identification. + + if Present (Library_Unit (N)) then + Set_Corresponding_Stub (Unit (Library_Unit (N)), N); + Analyze_Subunit (Library_Unit (N)); + Version_Update (Cunit (Main_Unit), Library_Unit (N)); + + -- Otherwise we must load the subunit and link to it + + else + -- Make sure that, if the subunit is preprocessed and -gnateG is + -- specified, the preprocessed file will be written. + + Lib.Analysing_Subunit_Of_Main := True; + Unum := + Load_Unit + (Load_Name => Subunit_Name, + Required => False, + Subunit => True, + Error_Node => N); + Lib.Analysing_Subunit_Of_Main := False; + + -- Give message if we did not get the unit Emit warning even if + -- missing subunit is not within main unit, to simplify debugging. + + if Original_Operating_Mode = Generate_Code + and then Unum = No_Unit + then + Error_Msg_Unit_1 := Subunit_Name; + Error_Msg_File_1 := + Get_File_Name (Subunit_Name, Subunit => True); + Error_Msg_N + ("subunit$$ in file{ not found??!!", N); + Subunits_Missing := True; + end if; + + -- Load_Unit may reset Compiler_State, since it may have been + -- necessary to parse an additional units, so we make sure that + -- we reset it to the Analyzing state. + + Compiler_State := Analyzing; + + if Unum /= No_Unit then + if Debug_Flag_L then + Write_Str ("*** Loaded subunit from stub. Analyze"); + Write_Eol; + end if; + + Comp_Unit := Cunit (Unum); + + -- Check for child unit instead of subunit + + if Nkind (Unit (Comp_Unit)) /= N_Subunit then + Error_Msg_N + ("expected SEPARATE subunit, found child unit", + Cunit_Entity (Unum)); + + -- OK, we have a subunit + + else + Set_Corresponding_Stub (Unit (Comp_Unit), N); + Set_Library_Unit (N, Comp_Unit); + + -- We update the version. Although we are not technically + -- semantically dependent on the subunit, given our approach + -- of macro substitution of subunits, it makes sense to + -- include it in the version identification. + + Version_Update (Cunit (Main_Unit), Comp_Unit); + + -- Collect SCO information for loaded subunit if we are in + -- the main unit. + + if Generate_SCO + and then + In_Extended_Main_Source_Unit + (Cunit_Entity (Current_Sem_Unit)) + then + SCO_Record (Unum); + end if; + + -- Analyze the unit if semantics active + + if not Fatal_Error (Unum) or else Try_Semantics then + Analyze_Subunit (Comp_Unit); + end if; + end if; + end if; + end if; + + -- The remaining case is when the subunit is not already loaded and we + -- are not generating code. In this case we are just performing semantic + -- analysis on the parent, and we are not interested in the subunit. For + -- subprograms, analyze the stub as a body. For other entities the stub + -- has already been marked as completed. + + else + Optional_Subunit; + end if; + end Analyze_Proper_Body; + + ---------------------------------- + -- Analyze_Protected_Body_Stub -- + ---------------------------------- + + procedure Analyze_Protected_Body_Stub (N : Node_Id) is + Nam : Entity_Id := Current_Entity_In_Scope (Defining_Identifier (N)); + + begin + Check_Stub_Level (N); + + -- First occurrence of name may have been as an incomplete type + + if Present (Nam) and then Ekind (Nam) = E_Incomplete_Type then + Nam := Full_View (Nam); + end if; + + if No (Nam) or else not Is_Protected_Type (Etype (Nam)) then + Error_Msg_N ("missing specification for Protected body", N); + + else + -- Currently there are no language-defined aspects that can apply to + -- a protected body stub. Issue an error and remove the aspects to + -- prevent cascaded errors. + + if Has_Aspects (N) then + Error_Msg_N + ("aspects on protected bodies are not allowed", + First (Aspect_Specifications (N))); + Remove_Aspects (N); + end if; + + Set_Scope (Defining_Entity (N), Current_Scope); + Set_Has_Completion (Etype (Nam)); + Set_Corresponding_Spec_Of_Stub (N, Nam); + Generate_Reference (Nam, Defining_Identifier (N), 'b'); + Analyze_Proper_Body (N, Etype (Nam)); + end if; + end Analyze_Protected_Body_Stub; + + ---------------------------------- + -- Analyze_Subprogram_Body_Stub -- + ---------------------------------- + + -- A subprogram body stub can appear with or without a previous spec. If + -- there is one, then the analysis of the body will find it and verify + -- conformance. The formals appearing in the specification of the stub play + -- no role, except for requiring an additional conformance check. If there + -- is no previous subprogram declaration, the stub acts as a spec, and + -- provides the defining entity for the subprogram. + + procedure Analyze_Subprogram_Body_Stub (N : Node_Id) is + Decl : Node_Id; + Opts : Config_Switches_Type; + + begin + Check_Stub_Level (N); + + -- Verify that the identifier for the stub is unique within this + -- declarative part. + + if Nkind_In (Parent (N), N_Block_Statement, + N_Package_Body, + N_Subprogram_Body) + then + Decl := First (Declarations (Parent (N))); + while Present (Decl) and then Decl /= N loop + if Nkind (Decl) = N_Subprogram_Body_Stub + and then (Chars (Defining_Unit_Name (Specification (Decl))) = + Chars (Defining_Unit_Name (Specification (N)))) + then + Error_Msg_N ("identifier for stub is not unique", N); + end if; + + Next (Decl); + end loop; + end if; + + -- Retain and restore the configuration options of the enclosing context + -- as the proper body may introduce a set of its own. + + Save_Opt_Config_Switches (Opts); + + -- Treat stub as a body, which checks conformance if there is a previous + -- declaration, or else introduces entity and its signature. + + Analyze_Subprogram_Body (N); + Analyze_Proper_Body (N, Empty); + + Restore_Opt_Config_Switches (Opts); + end Analyze_Subprogram_Body_Stub; + + --------------------- + -- Analyze_Subunit -- + --------------------- + + -- A subunit is compiled either by itself (for semantic checking) or as + -- part of compiling the parent (for code generation). In either case, by + -- the time we actually process the subunit, the parent has already been + -- installed and analyzed. The node N is a compilation unit, whose context + -- needs to be treated here, because we come directly here from the parent + -- without calling Analyze_Compilation_Unit. + + -- The compilation context includes the explicit context of the subunit, + -- and the context of the parent, together with the parent itself. In order + -- to compile the current context, we remove the one inherited from the + -- parent, in order to have a clean visibility table. We restore the parent + -- context before analyzing the proper body itself. On exit, we remove only + -- the explicit context of the subunit. + + procedure Analyze_Subunit (N : Node_Id) is + Lib_Unit : constant Node_Id := Library_Unit (N); + Par_Unit : constant Entity_Id := Current_Scope; + + Lib_Spec : Node_Id := Library_Unit (Lib_Unit); + Num_Scopes : Int := 0; + Use_Clauses : array (1 .. Scope_Stack.Last) of Node_Id; + Enclosing_Child : Entity_Id := Empty; + Svg : constant Suppress_Record := Scope_Suppress; + + Save_Cunit_Restrictions : constant Save_Cunit_Boolean_Restrictions := + Cunit_Boolean_Restrictions_Save; + -- Save non-partition wide restrictions before processing the subunit. + -- All subunits are analyzed with config restrictions reset and we need + -- to restore these saved values at the end. + + procedure Analyze_Subunit_Context; + -- Capture names in use clauses of the subunit. This must be done before + -- re-installing parent declarations, because items in the context must + -- not be hidden by declarations local to the parent. + + procedure Re_Install_Parents (L : Node_Id; Scop : Entity_Id); + -- Recursive procedure to restore scope of all ancestors of subunit, + -- from outermost in. If parent is not a subunit, the call to install + -- context installs context of spec and (if parent is a child unit) the + -- context of its parents as well. It is confusing that parents should + -- be treated differently in both cases, but the semantics are just not + -- identical. + + procedure Re_Install_Use_Clauses; + -- As part of the removal of the parent scope, the use clauses are + -- removed, to be reinstalled when the context of the subunit has been + -- analyzed. Use clauses may also have been affected by the analysis of + -- the context of the subunit, so they have to be applied again, to + -- insure that the compilation environment of the rest of the parent + -- unit is identical. + + procedure Remove_Scope; + -- Remove current scope from scope stack, and preserve the list of use + -- clauses in it, to be reinstalled after context is analyzed. + + ----------------------------- + -- Analyze_Subunit_Context -- + ----------------------------- + + procedure Analyze_Subunit_Context is + Item : Node_Id; + Nam : Node_Id; + Unit_Name : Entity_Id; + + begin + Analyze_Context (N); + + -- Make withed units immediately visible. If child unit, make the + -- ultimate parent immediately visible. + + Item := First (Context_Items (N)); + while Present (Item) loop + if Nkind (Item) = N_With_Clause then + + -- Protect frontend against previous errors in context clauses + + if Nkind (Name (Item)) /= N_Selected_Component then + if Error_Posted (Item) then + null; + + else + -- If a subunits has serious syntax errors, the context + -- may not have been loaded. Add a harmless unit name to + -- attempt processing. + + if Serious_Errors_Detected > 0 + and then No (Entity (Name (Item))) + then + Set_Entity (Name (Item), Standard_Standard); + end if; + + Unit_Name := Entity (Name (Item)); + loop + Set_Is_Visible_Lib_Unit (Unit_Name); + exit when Scope (Unit_Name) = Standard_Standard; + Unit_Name := Scope (Unit_Name); + + if No (Unit_Name) then + Check_Error_Detected; + return; + end if; + end loop; + + if not Is_Immediately_Visible (Unit_Name) then + Set_Is_Immediately_Visible (Unit_Name); + Set_Context_Installed (Item); + end if; + end if; + end if; + + elsif Nkind (Item) = N_Use_Package_Clause then + Nam := First (Names (Item)); + while Present (Nam) loop + Analyze (Nam); + Next (Nam); + end loop; + + elsif Nkind (Item) = N_Use_Type_Clause then + Nam := First (Subtype_Marks (Item)); + while Present (Nam) loop + Analyze (Nam); + Next (Nam); + end loop; + end if; + + Next (Item); + end loop; + + -- Reset visibility of withed units. They will be made visible again + -- when we install the subunit context. + + Item := First (Context_Items (N)); + while Present (Item) loop + if Nkind (Item) = N_With_Clause + + -- Protect frontend against previous errors in context clauses + + and then Nkind (Name (Item)) /= N_Selected_Component + and then not Error_Posted (Item) + then + Unit_Name := Entity (Name (Item)); + loop + Set_Is_Visible_Lib_Unit (Unit_Name, False); + exit when Scope (Unit_Name) = Standard_Standard; + Unit_Name := Scope (Unit_Name); + end loop; + + if Context_Installed (Item) then + Set_Is_Immediately_Visible (Unit_Name, False); + Set_Context_Installed (Item, False); + end if; + end if; + + Next (Item); + end loop; + end Analyze_Subunit_Context; + + ------------------------ + -- Re_Install_Parents -- + ------------------------ + + procedure Re_Install_Parents (L : Node_Id; Scop : Entity_Id) is + E : Entity_Id; + + begin + if Nkind (Unit (L)) = N_Subunit then + Re_Install_Parents (Library_Unit (L), Scope (Scop)); + end if; + + Install_Context (L); + + -- If the subunit occurs within a child unit, we must restore the + -- immediate visibility of any siblings that may occur in context. + + if Present (Enclosing_Child) then + Install_Siblings (Enclosing_Child, L); + end if; + + Push_Scope (Scop); + + if Scop /= Par_Unit then + Set_Is_Immediately_Visible (Scop); + end if; + + -- Make entities in scope visible again. For child units, restore + -- visibility only if they are actually in context. + + E := First_Entity (Current_Scope); + while Present (E) loop + if not Is_Child_Unit (E) or else Is_Visible_Lib_Unit (E) then + Set_Is_Immediately_Visible (E); + end if; + + Next_Entity (E); + end loop; + + -- A subunit appears within a body, and for a nested subunits all the + -- parents are bodies. Restore full visibility of their private + -- entities. + + if Is_Package_Or_Generic_Package (Scop) then + Set_In_Package_Body (Scop); + Install_Private_Declarations (Scop); + end if; + end Re_Install_Parents; + + ---------------------------- + -- Re_Install_Use_Clauses -- + ---------------------------- + + procedure Re_Install_Use_Clauses is + U : Node_Id; + begin + for J in reverse 1 .. Num_Scopes loop + U := Use_Clauses (J); + Scope_Stack.Table (Scope_Stack.Last - J + 1).First_Use_Clause := U; + Install_Use_Clauses (U, Force_Installation => True); + end loop; + end Re_Install_Use_Clauses; + + ------------------ + -- Remove_Scope -- + ------------------ + + procedure Remove_Scope is + E : Entity_Id; + + begin + Num_Scopes := Num_Scopes + 1; + Use_Clauses (Num_Scopes) := + Scope_Stack.Table (Scope_Stack.Last).First_Use_Clause; + + E := First_Entity (Current_Scope); + while Present (E) loop + Set_Is_Immediately_Visible (E, False); + Next_Entity (E); + end loop; + + if Is_Child_Unit (Current_Scope) then + Enclosing_Child := Current_Scope; + end if; + + Pop_Scope; + end Remove_Scope; + + -- Start of processing for Analyze_Subunit + + begin + -- For subunit in main extended unit, we reset the configuration values + -- for the non-partition-wide restrictions. For other units reset them. + + if In_Extended_Main_Source_Unit (N) then + Restore_Config_Cunit_Boolean_Restrictions; + else + Reset_Cunit_Boolean_Restrictions; + end if; + + if Style_Check then + declare + Nam : Node_Id := Name (Unit (N)); + + begin + if Nkind (Nam) = N_Selected_Component then + Nam := Selector_Name (Nam); + end if; + + Check_Identifier (Nam, Par_Unit); + end; + end if; + + if not Is_Empty_List (Context_Items (N)) then + + -- Save current use clauses + + Remove_Scope; + Remove_Context (Lib_Unit); + + -- Now remove parents and their context, including enclosing subunits + -- and the outer parent body which is not a subunit. + + if Present (Lib_Spec) then + Remove_Context (Lib_Spec); + + while Nkind (Unit (Lib_Spec)) = N_Subunit loop + Lib_Spec := Library_Unit (Lib_Spec); + Remove_Scope; + Remove_Context (Lib_Spec); + end loop; + + if Nkind (Unit (Lib_Unit)) = N_Subunit then + Remove_Scope; + end if; + + if Nkind (Unit (Lib_Spec)) = N_Package_Body then + Remove_Context (Library_Unit (Lib_Spec)); + end if; + end if; + + Set_Is_Immediately_Visible (Par_Unit, False); + + Analyze_Subunit_Context; + + Re_Install_Parents (Lib_Unit, Par_Unit); + Set_Is_Immediately_Visible (Par_Unit); + + -- If the context includes a child unit of the parent of the subunit, + -- the parent will have been removed from visibility, after compiling + -- that cousin in the context. The visibility of the parent must be + -- restored now. This also applies if the context includes another + -- subunit of the same parent which in turn includes a child unit in + -- its context. + + if Is_Package_Or_Generic_Package (Par_Unit) then + if not Is_Immediately_Visible (Par_Unit) + or else (Present (First_Entity (Par_Unit)) + and then not + Is_Immediately_Visible (First_Entity (Par_Unit))) + then + Set_Is_Immediately_Visible (Par_Unit); + Install_Visible_Declarations (Par_Unit); + Install_Private_Declarations (Par_Unit); + end if; + end if; + + Re_Install_Use_Clauses; + Install_Context (N); + + -- Restore state of suppress flags for current body + + Scope_Suppress := Svg; + + -- If the subunit is within a child unit, then siblings of any parent + -- unit that appear in the context clause of the subunit must also be + -- made immediately visible. + + if Present (Enclosing_Child) then + Install_Siblings (Enclosing_Child, N); + end if; + end if; + + Generate_Parent_References (Unit (N), Par_Unit); + Analyze (Proper_Body (Unit (N))); + Remove_Context (N); + + -- The subunit may contain a with_clause on a sibling of some ancestor. + -- Removing the context will remove from visibility those ancestor child + -- units, which must be restored to the visibility they have in the + -- enclosing body. + + if Present (Enclosing_Child) then + declare + C : Entity_Id; + begin + C := Current_Scope; + while Present (C) and then C /= Standard_Standard loop + Set_Is_Immediately_Visible (C); + Set_Is_Visible_Lib_Unit (C); + C := Scope (C); + end loop; + end; + end if; + + -- Deal with restore of restrictions + + Cunit_Boolean_Restrictions_Restore (Save_Cunit_Restrictions); + end Analyze_Subunit; + + ---------------------------- + -- Analyze_Task_Body_Stub -- + ---------------------------- + + procedure Analyze_Task_Body_Stub (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Nam : Entity_Id := Current_Entity_In_Scope (Defining_Identifier (N)); + + begin + Check_Stub_Level (N); + + -- First occurrence of name may have been as an incomplete type + + if Present (Nam) and then Ekind (Nam) = E_Incomplete_Type then + Nam := Full_View (Nam); + end if; + + if No (Nam) or else not Is_Task_Type (Etype (Nam)) then + Error_Msg_N ("missing specification for task body", N); + + else + -- Currently there are no language-defined aspects that can apply to + -- a task body stub. Issue an error and remove the aspects to prevent + -- cascaded errors. + + if Has_Aspects (N) then + Error_Msg_N + ("aspects on task bodies are not allowed", + First (Aspect_Specifications (N))); + Remove_Aspects (N); + end if; + + Set_Scope (Defining_Entity (N), Current_Scope); + Generate_Reference (Nam, Defining_Identifier (N), 'b'); + Set_Corresponding_Spec_Of_Stub (N, Nam); + + -- Check for duplicate stub, if so give message and terminate + + if Has_Completion (Etype (Nam)) then + Error_Msg_N ("duplicate stub for task", N); + return; + else + Set_Has_Completion (Etype (Nam)); + end if; + + Analyze_Proper_Body (N, Etype (Nam)); + + -- Set elaboration flag to indicate that entity is callable. This + -- cannot be done in the expansion of the body itself, because the + -- proper body is not in a declarative part. This is only done if + -- expansion is active, because the context may be generic and the + -- flag not defined yet. + + if Expander_Active then + Insert_After (N, + Make_Assignment_Statement (Loc, + Name => + Make_Identifier (Loc, + Chars => New_External_Name (Chars (Etype (Nam)), 'E')), + Expression => New_Occurrence_Of (Standard_True, Loc))); + end if; + end if; + end Analyze_Task_Body_Stub; + + ------------------------- + -- Analyze_With_Clause -- + ------------------------- + + -- Analyze the declaration of a unit in a with clause. At end, label the + -- with clause with the defining entity for the unit. + + procedure Analyze_With_Clause (N : Node_Id) is + + -- Retrieve the original kind of the unit node, before analysis. If it + -- is a subprogram instantiation, its analysis below will rewrite the + -- node as the declaration of the wrapper package. If the same + -- instantiation appears indirectly elsewhere in the context, it will + -- have been analyzed already. + + Unit_Kind : constant Node_Kind := + Nkind (Original_Node (Unit (Library_Unit (N)))); + Nam : constant Node_Id := Name (N); + E_Name : Entity_Id; + Par_Name : Entity_Id; + Pref : Node_Id; + U : Node_Id; + + Intunit : Boolean; + -- Set True if the unit currently being compiled is an internal unit + + Restriction_Violation : Boolean := False; + -- Set True if a with violates a restriction, no point in giving any + -- warnings if we have this definite error. + + Save_Style_Check : constant Boolean := Opt.Style_Check; + + begin + U := Unit (Library_Unit (N)); + + -- If this is an internal unit which is a renaming, then this is a + -- violation of No_Obsolescent_Features. + + -- Note: this is not quite right if the user defines one of these units + -- himself, but that's a marginal case, and fixing it is hard ??? + + if Restriction_Check_Required (No_Obsolescent_Features) then + declare + F : constant File_Name_Type := + Unit_File_Name (Get_Source_Unit (U)); + begin + if Is_Predefined_File_Name (F, Renamings_Included => True) + and then not + Is_Predefined_File_Name (F, Renamings_Included => False) + then + Check_Restriction (No_Obsolescent_Features, N); + Restriction_Violation := True; + end if; + end; + end if; + + -- Check No_Implementation_Units violation + + if Restriction_Check_Required (No_Implementation_Units) then + if Not_Impl_Defined_Unit (Get_Source_Unit (U)) then + null; + else + Check_Restriction (No_Implementation_Units, Nam); + Restriction_Violation := True; + end if; + end if; + + -- Several actions are skipped for dummy packages (those supplied for + -- with's where no matching file could be found). Such packages are + -- identified by the Sloc value being set to No_Location. + + if Limited_Present (N) then + + -- Ada 2005 (AI-50217): Build visibility structures but do not + -- analyze the unit. + + if Sloc (U) /= No_Location then + Build_Limited_Views (N); + end if; + + return; + end if; + + -- If the library unit is a predefined unit, and we are in high + -- integrity mode, then temporarily reset Configurable_Run_Time_Mode + -- for the analysis of the with'ed unit. This mode does not prevent + -- explicit with'ing of run-time units. + + if Configurable_Run_Time_Mode + and then Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (U))) + then + Configurable_Run_Time_Mode := False; + Semantics (Library_Unit (N)); + Configurable_Run_Time_Mode := True; + + else + Semantics (Library_Unit (N)); + end if; + + Intunit := Is_Internal_File_Name (Unit_File_Name (Current_Sem_Unit)); + + if Sloc (U) /= No_Location then + + -- Check restrictions, except that we skip the check if this is an + -- internal unit unless we are compiling the internal unit as the + -- main unit. We also skip this for dummy packages. + + Check_Restriction_No_Dependence (Nam, N); + + if not Intunit or else Current_Sem_Unit = Main_Unit then + Check_Restricted_Unit (Unit_Name (Get_Source_Unit (U)), N); + end if; + + -- Deal with special case of GNAT.Current_Exceptions which interacts + -- with the optimization of local raise statements into gotos. + + if Nkind (Nam) = N_Selected_Component + and then Nkind (Prefix (Nam)) = N_Identifier + and then Chars (Prefix (Nam)) = Name_Gnat + and then Nam_In (Chars (Selector_Name (Nam)), + Name_Most_Recent_Exception, + Name_Exception_Traces) + then + Check_Restriction (No_Exception_Propagation, N); + Special_Exception_Package_Used := True; + end if; + + -- Check for inappropriate with of internal implementation unit if we + -- are not compiling an internal unit and also check for withing unit + -- in wrong version of Ada. Do not issue these messages for implicit + -- with's generated by the compiler itself. + + if Implementation_Unit_Warnings + and then not Intunit + and then not Implicit_With (N) + and then not Restriction_Violation + then + declare + U_Kind : constant Kind_Of_Unit := + Get_Kind_Of_Unit (Get_Source_Unit (U)); + + begin + if U_Kind = Implementation_Unit then + Error_Msg_F ("& is an internal 'G'N'A'T unit?i?", Name (N)); + + -- Add alternative name if available, otherwise issue a + -- general warning message. + + if Error_Msg_Strlen /= 0 then + Error_Msg_F ("\use ""~"" instead?i?", Name (N)); + else + Error_Msg_F + ("\use of this unit is non-portable " & + "and version-dependent?i?", Name (N)); + end if; + + elsif U_Kind = Ada_2005_Unit + and then Ada_Version < Ada_2005 + and then Warn_On_Ada_2005_Compatibility + then + Error_Msg_N ("& is an Ada 2005 unit?i?", Name (N)); + + elsif U_Kind = Ada_2012_Unit + and then Ada_Version < Ada_2012 + and then Warn_On_Ada_2012_Compatibility + then + Error_Msg_N ("& is an Ada 2012 unit?i?", Name (N)); + end if; + end; + end if; + end if; + + -- Semantic analysis of a generic unit is performed on a copy of + -- the original tree. Retrieve the entity on which semantic info + -- actually appears. + + if Unit_Kind in N_Generic_Declaration then + E_Name := Defining_Entity (U); + + -- Note: in the following test, Unit_Kind is the original Nkind, but in + -- the case of an instantiation, semantic analysis above will have + -- replaced the unit by its instantiated version. If the instance body + -- has been generated, the instance now denotes the body entity. For + -- visibility purposes we need the entity of its spec. + + elsif (Unit_Kind = N_Package_Instantiation + or else Nkind (Original_Node (Unit (Library_Unit (N)))) = + N_Package_Instantiation) + and then Nkind (U) = N_Package_Body + then + E_Name := Corresponding_Spec (U); + + elsif Unit_Kind = N_Package_Instantiation + and then Nkind (U) = N_Package_Instantiation + and then Present (Instance_Spec (U)) + then + -- If the instance has not been rewritten as a package declaration, + -- then it appeared already in a previous with clause. Retrieve + -- the entity from the previous instance. + + E_Name := Defining_Entity (Specification (Instance_Spec (U))); + + elsif Unit_Kind in N_Subprogram_Instantiation then + + -- The visible subprogram is created during instantiation, and is + -- an attribute of the wrapper package. We retrieve the wrapper + -- package directly from the instantiation node. If the instance + -- is inlined the unit is still an instantiation. Otherwise it has + -- been rewritten as the declaration of the wrapper itself. + + if Nkind (U) in N_Subprogram_Instantiation then + E_Name := + Related_Instance + (Defining_Entity (Specification (Instance_Spec (U)))); + else + E_Name := Related_Instance (Defining_Entity (U)); + end if; + + elsif Unit_Kind = N_Package_Renaming_Declaration + or else Unit_Kind in N_Generic_Renaming_Declaration + then + E_Name := Defining_Entity (U); + + elsif Unit_Kind = N_Subprogram_Body + and then Nkind (Name (N)) = N_Selected_Component + and then not Acts_As_Spec (Library_Unit (N)) + then + -- For a child unit that has no spec, one has been created and + -- analyzed. The entity required is that of the spec. + + E_Name := Corresponding_Spec (U); + + else + E_Name := Defining_Entity (U); + end if; + + if Nkind (Name (N)) = N_Selected_Component then + + -- Child unit in a with clause + + Change_Selected_Component_To_Expanded_Name (Name (N)); + + -- If this is a child unit without a spec, and it has been analyzed + -- already, a declaration has been created for it. The with_clause + -- must reflect the actual body, and not the generated declaration, + -- to prevent spurious binding errors involving an out-of-date spec. + -- Note that this can only happen if the unit includes more than one + -- with_clause for the child unit (e.g. in separate subunits). + + if Unit_Kind = N_Subprogram_Declaration + and then Analyzed (Library_Unit (N)) + and then not Comes_From_Source (Library_Unit (N)) + then + Set_Library_Unit (N, + Cunit (Get_Source_Unit (Corresponding_Body (U)))); + end if; + end if; + + -- Restore style checks + + Style_Check := Save_Style_Check; + + -- Record the reference, but do NOT set the unit as referenced, we want + -- to consider the unit as unreferenced if this is the only reference + -- that occurs. + + Set_Entity_With_Checks (Name (N), E_Name); + Generate_Reference (E_Name, Name (N), 'w', Set_Ref => False); + + -- Generate references and check No_Dependence restriction for parents + + if Is_Child_Unit (E_Name) then + Pref := Prefix (Name (N)); + Par_Name := Scope (E_Name); + while Nkind (Pref) = N_Selected_Component loop + Change_Selected_Component_To_Expanded_Name (Pref); + + if Present (Entity (Selector_Name (Pref))) + and then + Present (Renamed_Entity (Entity (Selector_Name (Pref)))) + and then Entity (Selector_Name (Pref)) /= Par_Name + then + -- The prefix is a child unit that denotes a renaming declaration. + -- Replace the prefix directly with the renamed unit, because the + -- rest of the prefix is irrelevant to the visibility of the real + -- unit. + + Rewrite (Pref, New_Occurrence_Of (Par_Name, Sloc (Pref))); + exit; + end if; + + Set_Entity_With_Checks (Pref, Par_Name); + + Generate_Reference (Par_Name, Pref); + Check_Restriction_No_Dependence (Pref, N); + Pref := Prefix (Pref); + + -- If E_Name is the dummy entity for a nonexistent unit, its scope + -- is set to Standard_Standard, and no attempt should be made to + -- further unwind scopes. + + if Par_Name /= Standard_Standard then + Par_Name := Scope (Par_Name); + end if; + + -- Abandon processing in case of previous errors + + if No (Par_Name) then + Check_Error_Detected; + return; + end if; + end loop; + + if Present (Entity (Pref)) + and then not Analyzed (Parent (Parent (Entity (Pref)))) + then + -- If the entity is set without its unit being compiled, the + -- original parent is a renaming, and Par_Name is the renamed + -- entity. For visibility purposes, we need the original entity, + -- which must be analyzed now because Load_Unit directly retrieves + -- the renamed unit, and the renaming declaration itself has not + -- been analyzed. + + Analyze (Parent (Parent (Entity (Pref)))); + pragma Assert (Renamed_Object (Entity (Pref)) = Par_Name); + Par_Name := Entity (Pref); + end if; + + -- Guard against missing or misspelled child units + + if Present (Par_Name) then + Set_Entity_With_Checks (Pref, Par_Name); + Generate_Reference (Par_Name, Pref); + + else + pragma Assert (Serious_Errors_Detected /= 0); + + -- Mark the node to indicate that a related error has been posted. + -- This defends further compilation passes against improper use of + -- the invalid WITH clause node. + + Set_Error_Posted (N); + Set_Name (N, Error); + return; + end if; + end if; + + -- If the withed unit is System, and a system extension pragma is + -- present, compile the extension now, rather than waiting for a + -- visibility check on a specific entity. + + if Chars (E_Name) = Name_System + and then Scope (E_Name) = Standard_Standard + and then Present (System_Extend_Unit) + and then Present_System_Aux (N) + then + -- If the extension is not present, an error will have been emitted + + null; + end if; + + -- Ada 2005 (AI-262): Remove from visibility the entity corresponding + -- to private_with units; they will be made visible later (just before + -- the private part is analyzed) + + if Private_Present (N) then + Set_Is_Immediately_Visible (E_Name, False); + end if; + end Analyze_With_Clause; + + ------------------------------ + -- Check_Private_Child_Unit -- + ------------------------------ + + procedure Check_Private_Child_Unit (N : Node_Id) is + Lib_Unit : constant Node_Id := Unit (N); + Item : Node_Id; + Curr_Unit : Entity_Id; + Sub_Parent : Node_Id; + Priv_Child : Entity_Id; + Par_Lib : Entity_Id; + Par_Spec : Node_Id; + + function Is_Private_Library_Unit (Unit : Entity_Id) return Boolean; + -- Returns true if and only if the library unit is declared with + -- an explicit designation of private. + + ----------------------------- + -- Is_Private_Library_Unit -- + ----------------------------- + + function Is_Private_Library_Unit (Unit : Entity_Id) return Boolean is + Comp_Unit : constant Node_Id := Parent (Unit_Declaration_Node (Unit)); + + begin + return Private_Present (Comp_Unit); + end Is_Private_Library_Unit; + + -- Start of processing for Check_Private_Child_Unit + + begin + if Nkind_In (Lib_Unit, N_Package_Body, N_Subprogram_Body) then + Curr_Unit := Defining_Entity (Unit (Library_Unit (N))); + Par_Lib := Curr_Unit; + + elsif Nkind (Lib_Unit) = N_Subunit then + + -- The parent is itself a body. The parent entity is to be found in + -- the corresponding spec. + + Sub_Parent := Library_Unit (N); + Curr_Unit := Defining_Entity (Unit (Library_Unit (Sub_Parent))); + + -- If the parent itself is a subunit, Curr_Unit is the entity of the + -- enclosing body, retrieve the spec entity which is the proper + -- ancestor we need for the following tests. + + if Ekind (Curr_Unit) = E_Package_Body then + Curr_Unit := Spec_Entity (Curr_Unit); + end if; + + Par_Lib := Curr_Unit; + + else + Curr_Unit := Defining_Entity (Lib_Unit); + + Par_Lib := Curr_Unit; + Par_Spec := Parent_Spec (Lib_Unit); + + if No (Par_Spec) then + Par_Lib := Empty; + else + Par_Lib := Defining_Entity (Unit (Par_Spec)); + end if; + end if; + + -- Loop through context items + + Item := First (Context_Items (N)); + while Present (Item) loop + + -- Ada 2005 (AI-262): Allow private_with of a private child package + -- in public siblings + + if Nkind (Item) = N_With_Clause + and then not Implicit_With (Item) + and then not Limited_Present (Item) + and then Is_Private_Descendant (Entity (Name (Item))) + then + Priv_Child := Entity (Name (Item)); + + declare + Curr_Parent : Entity_Id := Par_Lib; + Child_Parent : Entity_Id := Scope (Priv_Child); + Prv_Ancestor : Entity_Id := Child_Parent; + Curr_Private : Boolean := Is_Private_Library_Unit (Curr_Unit); + + begin + -- If the child unit is a public child then locate the nearest + -- private ancestor. Child_Parent will then be set to the + -- parent of that ancestor. + + if not Is_Private_Library_Unit (Priv_Child) then + while Present (Prv_Ancestor) + and then not Is_Private_Library_Unit (Prv_Ancestor) + loop + Prv_Ancestor := Scope (Prv_Ancestor); + end loop; + + if Present (Prv_Ancestor) then + Child_Parent := Scope (Prv_Ancestor); + end if; + end if; + + while Present (Curr_Parent) + and then Curr_Parent /= Standard_Standard + and then Curr_Parent /= Child_Parent + loop + Curr_Private := + Curr_Private or else Is_Private_Library_Unit (Curr_Parent); + Curr_Parent := Scope (Curr_Parent); + end loop; + + if No (Curr_Parent) then + Curr_Parent := Standard_Standard; + end if; + + if Curr_Parent /= Child_Parent then + if Ekind (Priv_Child) = E_Generic_Package + and then Chars (Priv_Child) in Text_IO_Package_Name + and then Chars (Scope (Scope (Priv_Child))) = Name_Ada + then + Error_Msg_NE + ("& is a nested package, not a compilation unit", + Name (Item), Priv_Child); + + else + Error_Msg_N + ("unit in with clause is private child unit!", Item); + Error_Msg_NE + ("\current unit must also have parent&!", + Item, Child_Parent); + end if; + + elsif Curr_Private + or else Private_Present (Item) + or else Nkind_In (Lib_Unit, N_Package_Body, N_Subunit) + or else (Nkind (Lib_Unit) = N_Subprogram_Body + and then not Acts_As_Spec (Parent (Lib_Unit))) + then + null; + + else + Error_Msg_NE + ("current unit must also be private descendant of&", + Item, Child_Parent); + end if; + end; + end if; + + Next (Item); + end loop; + + end Check_Private_Child_Unit; + + ---------------------- + -- Check_Stub_Level -- + ---------------------- + + procedure Check_Stub_Level (N : Node_Id) is + Par : constant Node_Id := Parent (N); + Kind : constant Node_Kind := Nkind (Par); + + begin + if Nkind_In (Kind, N_Package_Body, + N_Subprogram_Body, + N_Task_Body, + N_Protected_Body) + and then Nkind_In (Parent (Par), N_Compilation_Unit, N_Subunit) + then + null; + + -- In an instance, a missing stub appears at any level. A warning + -- message will have been emitted already for the missing file. + + elsif not In_Instance then + Error_Msg_N ("stub cannot appear in an inner scope", N); + + elsif Expander_Active then + Error_Msg_N ("missing proper body", N); + end if; + end Check_Stub_Level; + + ------------------------ + -- Expand_With_Clause -- + ------------------------ + + procedure Expand_With_Clause (Item : Node_Id; Nam : Node_Id; N : Node_Id) is + Loc : constant Source_Ptr := Sloc (Nam); + Ent : constant Entity_Id := Entity (Nam); + Withn : Node_Id; + P : Node_Id; + + function Build_Unit_Name (Nam : Node_Id) return Node_Id; + -- Build name to be used in implicit with_clause. In most cases this + -- is the source name, but if renamings are present we must make the + -- original unit visible, not the one it renames. The entity in the + -- with clause is the renamed unit, but the identifier is the one from + -- the source, which allows us to recover the unit renaming. + + --------------------- + -- Build_Unit_Name -- + --------------------- + + function Build_Unit_Name (Nam : Node_Id) return Node_Id is + Ent : Entity_Id; + Result : Node_Id; + + begin + if Nkind (Nam) = N_Identifier then + return New_Occurrence_Of (Entity (Nam), Loc); + + else + Ent := Entity (Nam); + + if Present (Entity (Selector_Name (Nam))) + and then Chars (Entity (Selector_Name (Nam))) /= Chars (Ent) + and then + Nkind (Unit_Declaration_Node (Entity (Selector_Name (Nam)))) + = N_Package_Renaming_Declaration + then + -- The name in the with_clause is of the form A.B.C, and B is + -- given by a renaming declaration. In that case we may not + -- have analyzed the unit for B, but replaced it directly in + -- lib-load with the unit it renames. We have to make A.B + -- visible, so analyze the declaration for B now, in case it + -- has not been done yet. + + Ent := Entity (Selector_Name (Nam)); + Analyze + (Parent + (Unit_Declaration_Node (Entity (Selector_Name (Nam))))); + end if; + + Result := + Make_Expanded_Name (Loc, + Chars => Chars (Entity (Nam)), + Prefix => Build_Unit_Name (Prefix (Nam)), + Selector_Name => New_Occurrence_Of (Ent, Loc)); + Set_Entity (Result, Ent); + return Result; + end if; + end Build_Unit_Name; + + -- Start of processing for Expand_With_Clause + + begin + Withn := + Make_With_Clause (Loc, + Name => Build_Unit_Name (Nam)); + + P := Parent (Unit_Declaration_Node (Ent)); + Set_Library_Unit (Withn, P); + Set_Corresponding_Spec (Withn, Ent); + Set_First_Name (Withn, True); + Set_Implicit_With (Withn, True); + + -- If the unit is a package or generic package declaration, a private_ + -- with_clause on a child unit implies that the implicit with on the + -- parent is also private. + + if Nkind_In (Unit (N), N_Package_Declaration, + N_Generic_Package_Declaration) + then + Set_Private_Present (Withn, Private_Present (Item)); + end if; + + Prepend (Withn, Context_Items (N)); + Mark_Rewrite_Insertion (Withn); + Install_Withed_Unit (Withn); + + -- If we have "with X.Y;", we want to recurse on "X", except in the + -- unusual case where X.Y is a renaming of X. In that case, the scope + -- of X will be null. + + if Nkind (Nam) = N_Expanded_Name + and then Present (Scope (Entity (Prefix (Nam)))) + then + Expand_With_Clause (Item, Prefix (Nam), N); + end if; + end Expand_With_Clause; + + -------------------------------- + -- Generate_Parent_References -- + -------------------------------- + + procedure Generate_Parent_References (N : Node_Id; P_Id : Entity_Id) is + Pref : Node_Id; + P_Name : Entity_Id := P_Id; + + begin + if Nkind (N) = N_Subunit then + Pref := Name (N); + else + Pref := Name (Parent (Defining_Entity (N))); + end if; + + if Nkind (Pref) = N_Expanded_Name then + + -- Done already, if the unit has been compiled indirectly as + -- part of the closure of its context because of inlining. + + return; + end if; + + while Nkind (Pref) = N_Selected_Component loop + Change_Selected_Component_To_Expanded_Name (Pref); + Set_Entity (Pref, P_Name); + Set_Etype (Pref, Etype (P_Name)); + Generate_Reference (P_Name, Pref, 'r'); + Pref := Prefix (Pref); + P_Name := Scope (P_Name); + end loop; + + -- The guard here on P_Name is to handle the error condition where + -- the parent unit is missing because the file was not found. + + if Present (P_Name) then + Set_Entity (Pref, P_Name); + Set_Etype (Pref, Etype (P_Name)); + Generate_Reference (P_Name, Pref, 'r'); + Style.Check_Identifier (Pref, P_Name); + end if; + end Generate_Parent_References; + + ----------------------- + -- Get_Parent_Entity -- + ----------------------- + + function Get_Parent_Entity (Unit : Node_Id) return Entity_Id is + begin + if Nkind (Unit) = N_Package_Body + and then Nkind (Original_Node (Unit)) = N_Package_Instantiation + then + return Defining_Entity + (Specification (Instance_Spec (Original_Node (Unit)))); + elsif Nkind (Unit) = N_Package_Instantiation then + return Defining_Entity (Specification (Instance_Spec (Unit))); + else + return Defining_Entity (Unit); + end if; + end Get_Parent_Entity; + + --------------------- + -- Has_With_Clause -- + --------------------- + + function Has_With_Clause + (C_Unit : Node_Id; + Pack : Entity_Id; + Is_Limited : Boolean := False) return Boolean + is + Item : Node_Id; + + function Named_Unit (Clause : Node_Id) return Entity_Id; + -- Return the entity for the unit named in a [limited] with clause + + ---------------- + -- Named_Unit -- + ---------------- + + function Named_Unit (Clause : Node_Id) return Entity_Id is + begin + if Nkind (Name (Clause)) = N_Selected_Component then + return Entity (Selector_Name (Name (Clause))); + else + return Entity (Name (Clause)); + end if; + end Named_Unit; + + -- Start of processing for Has_With_Clause + + begin + if Present (Context_Items (C_Unit)) then + Item := First (Context_Items (C_Unit)); + while Present (Item) loop + if Nkind (Item) = N_With_Clause + and then Limited_Present (Item) = Is_Limited + and then Named_Unit (Item) = Pack + then + return True; + end if; + + Next (Item); + end loop; + end if; + + return False; + end Has_With_Clause; + + ----------------------------- + -- Implicit_With_On_Parent -- + ----------------------------- + + procedure Implicit_With_On_Parent + (Child_Unit : Node_Id; + N : Node_Id) + is + Loc : constant Source_Ptr := Sloc (N); + P : constant Node_Id := Parent_Spec (Child_Unit); + P_Unit : Node_Id := Unit (P); + P_Name : constant Entity_Id := Get_Parent_Entity (P_Unit); + Withn : Node_Id; + + function Build_Ancestor_Name (P : Node_Id) return Node_Id; + -- Build prefix of child unit name. Recurse if needed + + function Build_Unit_Name return Node_Id; + -- If the unit is a child unit, build qualified name with all ancestors + + ------------------------- + -- Build_Ancestor_Name -- + ------------------------- + + function Build_Ancestor_Name (P : Node_Id) return Node_Id is + P_Ref : constant Node_Id := + New_Occurrence_Of (Defining_Entity (P), Loc); + P_Spec : Node_Id := P; + + begin + -- Ancestor may have been rewritten as a package body. Retrieve + -- the original spec to trace earlier ancestors. + + if Nkind (P) = N_Package_Body + and then Nkind (Original_Node (P)) = N_Package_Instantiation + then + P_Spec := Original_Node (P); + end if; + + if No (Parent_Spec (P_Spec)) then + return P_Ref; + else + return + Make_Selected_Component (Loc, + Prefix => Build_Ancestor_Name (Unit (Parent_Spec (P_Spec))), + Selector_Name => P_Ref); + end if; + end Build_Ancestor_Name; + + --------------------- + -- Build_Unit_Name -- + --------------------- + + function Build_Unit_Name return Node_Id is + Result : Node_Id; + + begin + if No (Parent_Spec (P_Unit)) then + return New_Occurrence_Of (P_Name, Loc); + + else + Result := + Make_Expanded_Name (Loc, + Chars => Chars (P_Name), + Prefix => Build_Ancestor_Name (Unit (Parent_Spec (P_Unit))), + Selector_Name => New_Occurrence_Of (P_Name, Loc)); + Set_Entity (Result, P_Name); + return Result; + end if; + end Build_Unit_Name; + + -- Start of processing for Implicit_With_On_Parent + + begin + -- The unit of the current compilation may be a package body that + -- replaces an instance node. In this case we need the original instance + -- node to construct the proper parent name. + + if Nkind (P_Unit) = N_Package_Body + and then Nkind (Original_Node (P_Unit)) = N_Package_Instantiation + then + P_Unit := Original_Node (P_Unit); + end if; + + -- We add the implicit with if the child unit is the current unit being + -- compiled. If the current unit is a body, we do not want to add an + -- implicit_with a second time to the corresponding spec. + + if Nkind (Child_Unit) = N_Package_Declaration + and then Child_Unit /= Unit (Cunit (Current_Sem_Unit)) + then + return; + end if; + + Withn := Make_With_Clause (Loc, Name => Build_Unit_Name); + + Set_Library_Unit (Withn, P); + Set_Corresponding_Spec (Withn, P_Name); + Set_First_Name (Withn, True); + Set_Implicit_With (Withn, True); + + -- Node is placed at the beginning of the context items, so that + -- subsequent use clauses on the parent can be validated. + + Prepend (Withn, Context_Items (N)); + Mark_Rewrite_Insertion (Withn); + Install_Withed_Unit (Withn); + + if Is_Child_Spec (P_Unit) then + Implicit_With_On_Parent (P_Unit, N); + end if; + end Implicit_With_On_Parent; + + -------------- + -- In_Chain -- + -------------- + + function In_Chain (E : Entity_Id) return Boolean is + H : Entity_Id; + + begin + H := Current_Entity (E); + while Present (H) loop + if H = E then + return True; + else + H := Homonym (H); + end if; + end loop; + + return False; + end In_Chain; + + --------------------- + -- Install_Context -- + --------------------- + + procedure Install_Context (N : Node_Id) is + Lib_Unit : constant Node_Id := Unit (N); + + begin + Install_Context_Clauses (N); + + if Is_Child_Spec (Lib_Unit) then + Install_Parents (Lib_Unit, Private_Present (Parent (Lib_Unit))); + end if; + + Install_Limited_Context_Clauses (N); + end Install_Context; + + ----------------------------- + -- Install_Context_Clauses -- + ----------------------------- + + procedure Install_Context_Clauses (N : Node_Id) is + Lib_Unit : constant Node_Id := Unit (N); + Item : Node_Id; + Uname_Node : Entity_Id; + Check_Private : Boolean := False; + Decl_Node : Node_Id; + Lib_Parent : Entity_Id; + + begin + -- First skip configuration pragmas at the start of the context. They + -- are not technically part of the context clause, but that's where the + -- parser puts them. Note they were analyzed in Analyze_Context. + + Item := First (Context_Items (N)); + while Present (Item) + and then Nkind (Item) = N_Pragma + and then Pragma_Name (Item) in Configuration_Pragma_Names + loop + Next (Item); + end loop; + + -- Loop through the actual context clause items. We process everything + -- except Limited_With clauses in this routine. Limited_With clauses + -- are separately installed (see Install_Limited_Context_Clauses). + + while Present (Item) loop + + -- Case of explicit WITH clause + + if Nkind (Item) = N_With_Clause + and then not Implicit_With (Item) + then + if Limited_Present (Item) then + + -- Limited withed units will be installed later + + goto Continue; + + -- If Name (Item) is not an entity name, something is wrong, and + -- this will be detected in due course, for now ignore the item + + elsif not Is_Entity_Name (Name (Item)) then + goto Continue; + + elsif No (Entity (Name (Item))) then + Set_Entity (Name (Item), Any_Id); + goto Continue; + end if; + + Uname_Node := Entity (Name (Item)); + + if Is_Private_Descendant (Uname_Node) then + Check_Private := True; + end if; + + Install_Withed_Unit (Item); + + Decl_Node := Unit_Declaration_Node (Uname_Node); + + -- If the unit is a subprogram instance, it appears nested within + -- a package that carries the parent information. + + if Is_Generic_Instance (Uname_Node) + and then Ekind (Uname_Node) /= E_Package + then + Decl_Node := Parent (Parent (Decl_Node)); + end if; + + if Is_Child_Spec (Decl_Node) then + if Nkind (Name (Item)) = N_Expanded_Name then + Expand_With_Clause (Item, Prefix (Name (Item)), N); + else + -- If not an expanded name, the child unit must be a + -- renaming, nothing to do. + + null; + end if; + + elsif Nkind (Decl_Node) = N_Subprogram_Body + and then not Acts_As_Spec (Parent (Decl_Node)) + and then Is_Child_Spec (Unit (Library_Unit (Parent (Decl_Node)))) + then + Implicit_With_On_Parent + (Unit (Library_Unit (Parent (Decl_Node))), N); + end if; + + -- Check license conditions unless this is a dummy unit + + if Sloc (Library_Unit (Item)) /= No_Location then + License_Check : declare + Withu : constant Unit_Number_Type := + Get_Source_Unit (Library_Unit (Item)); + Withl : constant License_Type := + License (Source_Index (Withu)); + Unitl : constant License_Type := + License (Source_Index (Current_Sem_Unit)); + + procedure License_Error; + -- Signal error of bad license + + ------------------- + -- License_Error -- + ------------------- + + procedure License_Error is + begin + Error_Msg_N + ("license of withed unit & may be inconsistent??", + Name (Item)); + end License_Error; + + -- Start of processing for License_Check + + begin + -- Exclude license check if withed unit is an internal unit. + -- This situation arises e.g. with the GPL version of GNAT. + + if Is_Internal_File_Name (Unit_File_Name (Withu)) then + null; + + -- Otherwise check various cases + else + case Unitl is + when Unknown => + null; + + when Restricted => + if Withl = GPL then + License_Error; + end if; + + when GPL => + if Withl = Restricted then + License_Error; + end if; + + when Modified_GPL => + if Withl = Restricted or else Withl = GPL then + License_Error; + end if; + + when Unrestricted => + null; + end case; + end if; + end License_Check; + end if; + + -- Case of USE PACKAGE clause + + elsif Nkind (Item) = N_Use_Package_Clause then + Analyze_Use_Package (Item); + + -- Case of USE TYPE clause + + elsif Nkind (Item) = N_Use_Type_Clause then + Analyze_Use_Type (Item); + + -- case of PRAGMA + + elsif Nkind (Item) = N_Pragma then + Analyze (Item); + end if; + + <<Continue>> + Next (Item); + end loop; + + if Is_Child_Spec (Lib_Unit) then + + -- The unit also has implicit with_clauses on its own parents + + if No (Context_Items (N)) then + Set_Context_Items (N, New_List); + end if; + + Implicit_With_On_Parent (Lib_Unit, N); + end if; + + -- If the unit is a body, the context of the specification must also + -- be installed. That includes private with_clauses in that context. + + if Nkind (Lib_Unit) = N_Package_Body + or else (Nkind (Lib_Unit) = N_Subprogram_Body + and then not Acts_As_Spec (N)) + then + Install_Context (Library_Unit (N)); + + -- Only install private with-clauses of a spec that comes from + -- source, excluding specs created for a subprogram body that is + -- a child unit. + + if Comes_From_Source (Library_Unit (N)) then + Install_Private_With_Clauses + (Defining_Entity (Unit (Library_Unit (N)))); + end if; + + if Is_Child_Spec (Unit (Library_Unit (N))) then + + -- If the unit is the body of a public child unit, the private + -- declarations of the parent must be made visible. If the child + -- unit is private, the private declarations have been installed + -- already in the call to Install_Parents for the spec. Installing + -- private declarations must be done for all ancestors of public + -- child units. In addition, sibling units mentioned in the + -- context clause of the body are directly visible. + + declare + Lib_Spec : Node_Id; + P : Node_Id; + P_Name : Entity_Id; + + begin + Lib_Spec := Unit (Library_Unit (N)); + while Is_Child_Spec (Lib_Spec) loop + P := Unit (Parent_Spec (Lib_Spec)); + P_Name := Defining_Entity (P); + + if not (Private_Present (Parent (Lib_Spec))) + and then not In_Private_Part (P_Name) + then + Install_Private_Declarations (P_Name); + Install_Private_With_Clauses (P_Name); + Set_Use (Private_Declarations (Specification (P))); + end if; + + Lib_Spec := P; + end loop; + end; + end if; + + -- For a package body, children in context are immediately visible + + Install_Siblings (Defining_Entity (Unit (Library_Unit (N))), N); + end if; + + if Nkind_In (Lib_Unit, N_Generic_Package_Declaration, + N_Generic_Subprogram_Declaration, + N_Package_Declaration, + N_Subprogram_Declaration) + then + if Is_Child_Spec (Lib_Unit) then + Lib_Parent := Defining_Entity (Unit (Parent_Spec (Lib_Unit))); + Set_Is_Private_Descendant + (Defining_Entity (Lib_Unit), + Is_Private_Descendant (Lib_Parent) + or else Private_Present (Parent (Lib_Unit))); + + else + Set_Is_Private_Descendant + (Defining_Entity (Lib_Unit), + Private_Present (Parent (Lib_Unit))); + end if; + end if; + + if Check_Private then + Check_Private_Child_Unit (N); + end if; + end Install_Context_Clauses; + + ------------------------------------- + -- Install_Limited_Context_Clauses -- + ------------------------------------- + + procedure Install_Limited_Context_Clauses (N : Node_Id) is + Item : Node_Id; + + procedure Check_Renamings (P : Node_Id; W : Node_Id); + -- Check that the unlimited view of a given compilation_unit is not + -- already visible through "use + renamings". + + procedure Check_Private_Limited_Withed_Unit (Item : Node_Id); + -- Check that if a limited_with clause of a given compilation_unit + -- mentions a descendant of a private child of some library unit, then + -- the given compilation_unit shall be the declaration of a private + -- descendant of that library unit, or a public descendant of such. The + -- code is analogous to that of Check_Private_Child_Unit but we cannot + -- use entities on the limited with_clauses because their units have not + -- been analyzed, so we have to climb the tree of ancestors looking for + -- private keywords. + + procedure Expand_Limited_With_Clause + (Comp_Unit : Node_Id; + Nam : Node_Id; + N : Node_Id); + -- If a child unit appears in a limited_with clause, there are implicit + -- limited_with clauses on all parents that are not already visible + -- through a regular with clause. This procedure creates the implicit + -- limited with_clauses for the parents and loads the corresponding + -- units. The shadow entities are created when the inserted clause is + -- analyzed. Implements Ada 2005 (AI-50217). + + --------------------- + -- Check_Renamings -- + --------------------- + + procedure Check_Renamings (P : Node_Id; W : Node_Id) is + Item : Node_Id; + Spec : Node_Id; + WEnt : Entity_Id; + Nam : Node_Id; + E : Entity_Id; + E2 : Entity_Id; + + begin + pragma Assert (Nkind (W) = N_With_Clause); + + -- Protect the frontend against previous critical errors + + case Nkind (Unit (Library_Unit (W))) is + when N_Subprogram_Declaration | + N_Package_Declaration | + N_Generic_Subprogram_Declaration | + N_Generic_Package_Declaration => + null; + + when others => + return; + end case; + + -- Check "use + renamings" + + WEnt := Defining_Unit_Name (Specification (Unit (Library_Unit (W)))); + Spec := Specification (Unit (P)); + + Item := First (Visible_Declarations (Spec)); + while Present (Item) loop + + -- Look only at use package clauses + + if Nkind (Item) = N_Use_Package_Clause then + + -- Traverse the list of packages + + Nam := First (Names (Item)); + while Present (Nam) loop + E := Entity (Nam); + + pragma Assert (Present (Parent (E))); + + if Nkind (Parent (E)) = N_Package_Renaming_Declaration + and then Renamed_Entity (E) = WEnt + then + -- The unlimited view is visible through use clause and + -- renamings. There is no need to generate the error + -- message here because Is_Visible_Through_Renamings + -- takes care of generating the precise error message. + + return; + + elsif Nkind (Parent (E)) = N_Package_Specification then + + -- The use clause may refer to a local package. + -- Check all the enclosing scopes. + + E2 := E; + while E2 /= Standard_Standard and then E2 /= WEnt loop + E2 := Scope (E2); + end loop; + + if E2 = WEnt then + Error_Msg_N + ("unlimited view visible through use clause ", W); + return; + end if; + end if; + + Next (Nam); + end loop; + end if; + + Next (Item); + end loop; + + -- Recursive call to check all the ancestors + + if Is_Child_Spec (Unit (P)) then + Check_Renamings (P => Parent_Spec (Unit (P)), W => W); + end if; + end Check_Renamings; + + --------------------------------------- + -- Check_Private_Limited_Withed_Unit -- + --------------------------------------- + + procedure Check_Private_Limited_Withed_Unit (Item : Node_Id) is + Curr_Parent : Node_Id; + Child_Parent : Node_Id; + Curr_Private : Boolean; + + begin + -- Compilation unit of the parent of the withed library unit + + Child_Parent := Library_Unit (Item); + + -- If the child unit is a public child, then locate its nearest + -- private ancestor, if any, then Child_Parent will then be set to + -- the parent of that ancestor. + + if not Private_Present (Library_Unit (Item)) then + while Present (Child_Parent) + and then not Private_Present (Child_Parent) + loop + Child_Parent := Parent_Spec (Unit (Child_Parent)); + end loop; + + if No (Child_Parent) then + return; + end if; + end if; + + Child_Parent := Parent_Spec (Unit (Child_Parent)); + + -- Traverse all the ancestors of the current compilation unit to + -- check if it is a descendant of named library unit. + + Curr_Parent := Parent (Item); + Curr_Private := Private_Present (Curr_Parent); + + while Present (Parent_Spec (Unit (Curr_Parent))) + and then Curr_Parent /= Child_Parent + loop + Curr_Parent := Parent_Spec (Unit (Curr_Parent)); + Curr_Private := Curr_Private or else Private_Present (Curr_Parent); + end loop; + + if Curr_Parent /= Child_Parent then + Error_Msg_N + ("unit in with clause is private child unit!", Item); + Error_Msg_NE + ("\current unit must also have parent&!", + Item, Defining_Unit_Name (Specification (Unit (Child_Parent)))); + + elsif Private_Present (Parent (Item)) + or else Curr_Private + or else Private_Present (Item) + or else Nkind_In (Unit (Parent (Item)), N_Package_Body, + N_Subprogram_Body, + N_Subunit) + then + -- Current unit is private, of descendant of a private unit + + null; + + else + Error_Msg_NE + ("current unit must also be private descendant of&", + Item, Defining_Unit_Name (Specification (Unit (Child_Parent)))); + end if; + end Check_Private_Limited_Withed_Unit; + + -------------------------------- + -- Expand_Limited_With_Clause -- + -------------------------------- + + procedure Expand_Limited_With_Clause + (Comp_Unit : Node_Id; + Nam : Node_Id; + N : Node_Id) + is + Loc : constant Source_Ptr := Sloc (Nam); + Unum : Unit_Number_Type; + Withn : Node_Id; + + function Previous_Withed_Unit (W : Node_Id) return Boolean; + -- Returns true if the context already includes a with_clause for + -- this unit. If the with_clause is non-limited, the unit is fully + -- visible and an implicit limited_with should not be created. If + -- there is already a limited_with clause for W, a second one is + -- simply redundant. + + -------------------------- + -- Previous_Withed_Unit -- + -------------------------- + + function Previous_Withed_Unit (W : Node_Id) return Boolean is + Item : Node_Id; + + begin + -- A limited with_clause cannot appear in the same context_clause + -- as a nonlimited with_clause which mentions the same library. + + Item := First (Context_Items (Comp_Unit)); + while Present (Item) loop + if Nkind (Item) = N_With_Clause + and then Library_Unit (Item) = Library_Unit (W) + then + return True; + end if; + + Next (Item); + end loop; + + return False; + end Previous_Withed_Unit; + + -- Start of processing for Expand_Limited_With_Clause + + begin + if Nkind (Nam) = N_Identifier then + + -- Create node for name of withed unit + + Withn := + Make_With_Clause (Loc, + Name => New_Copy (Nam)); + + else pragma Assert (Nkind (Nam) = N_Selected_Component); + Withn := + Make_With_Clause (Loc, + Name => Make_Selected_Component (Loc, + Prefix => New_Copy_Tree (Prefix (Nam)), + Selector_Name => New_Copy (Selector_Name (Nam)))); + Set_Parent (Withn, Parent (N)); + end if; + + Set_Limited_Present (Withn); + Set_First_Name (Withn); + Set_Implicit_With (Withn); + + Unum := + Load_Unit + (Load_Name => Get_Spec_Name (Get_Unit_Name (Nam)), + Required => True, + Subunit => False, + Error_Node => Nam); + + -- Do not generate a limited_with_clause on the current unit. This + -- path is taken when a unit has a limited_with clause on one of its + -- child units. + + if Unum = Current_Sem_Unit then + return; + end if; + + Set_Library_Unit (Withn, Cunit (Unum)); + Set_Corresponding_Spec + (Withn, Specification (Unit (Cunit (Unum)))); + + if not Previous_Withed_Unit (Withn) then + Prepend (Withn, Context_Items (Parent (N))); + Mark_Rewrite_Insertion (Withn); + + -- Add implicit limited_with_clauses for parents of child units + -- mentioned in limited_with clauses. + + if Nkind (Nam) = N_Selected_Component then + Expand_Limited_With_Clause (Comp_Unit, Prefix (Nam), N); + end if; + + Analyze (Withn); + + if not Limited_View_Installed (Withn) then + Install_Limited_Withed_Unit (Withn); + end if; + end if; + end Expand_Limited_With_Clause; + + -- Start of processing for Install_Limited_Context_Clauses + + begin + Item := First (Context_Items (N)); + while Present (Item) loop + if Nkind (Item) = N_With_Clause + and then Limited_Present (Item) + and then not Error_Posted (Item) + then + if Nkind (Name (Item)) = N_Selected_Component then + Expand_Limited_With_Clause + (Comp_Unit => N, Nam => Prefix (Name (Item)), N => Item); + end if; + + Check_Private_Limited_Withed_Unit (Item); + + if not Implicit_With (Item) and then Is_Child_Spec (Unit (N)) then + Check_Renamings (Parent_Spec (Unit (N)), Item); + end if; + + -- A unit may have a limited with on itself if it has a limited + -- with_clause on one of its child units. In that case it is + -- already being compiled and it makes no sense to install its + -- limited view. + + -- If the item is a limited_private_with_clause, install it if the + -- current unit is a body or if it is a private child. Otherwise + -- the private clause is installed before analyzing the private + -- part of the current unit. + + if Library_Unit (Item) /= Cunit (Current_Sem_Unit) + and then not Limited_View_Installed (Item) + and then + not Is_Ancestor_Unit + (Library_Unit (Item), Cunit (Current_Sem_Unit)) + then + if not Private_Present (Item) + or else Private_Present (N) + or else Nkind_In (Unit (N), N_Package_Body, + N_Subprogram_Body, + N_Subunit) + then + Install_Limited_Withed_Unit (Item); + end if; + end if; + end if; + + Next (Item); + end loop; + + -- Ada 2005 (AI-412): Examine visible declarations of a package spec, + -- looking for incomplete subtype declarations of incomplete types + -- visible through a limited with clause. + + if Ada_Version >= Ada_2005 + and then Analyzed (N) + and then Nkind (Unit (N)) = N_Package_Declaration + then + declare + Decl : Node_Id; + Def_Id : Entity_Id; + Non_Lim_View : Entity_Id; + + begin + Decl := First (Visible_Declarations (Specification (Unit (N)))); + while Present (Decl) loop + if Nkind (Decl) = N_Subtype_Declaration + and then + Ekind (Defining_Identifier (Decl)) = E_Incomplete_Subtype + and then + From_Limited_With (Defining_Identifier (Decl)) + then + Def_Id := Defining_Identifier (Decl); + Non_Lim_View := Non_Limited_View (Def_Id); + + if not Is_Incomplete_Type (Non_Lim_View) then + + -- Convert an incomplete subtype declaration into a + -- corresponding non-limited view subtype declaration. + -- This is usually the case when analyzing a body that + -- has regular with clauses, when the spec has limited + -- ones. + + -- If the non-limited view is still incomplete, it is + -- the dummy entry already created, and the declaration + -- cannot be reanalyzed. This is the case when installing + -- a parent unit that has limited with-clauses. + + Set_Subtype_Indication (Decl, + New_Occurrence_Of (Non_Lim_View, Sloc (Def_Id))); + Set_Etype (Def_Id, Non_Lim_View); + Set_Ekind (Def_Id, Subtype_Kind (Ekind (Non_Lim_View))); + Set_Analyzed (Decl, False); + + -- Reanalyze the declaration, suppressing the call to + -- Enter_Name to avoid duplicate names. + + Analyze_Subtype_Declaration + (N => Decl, + Skip => True); + end if; + end if; + + Next (Decl); + end loop; + end; + end if; + end Install_Limited_Context_Clauses; + + --------------------- + -- Install_Parents -- + --------------------- + + procedure Install_Parents (Lib_Unit : Node_Id; Is_Private : Boolean) is + P : Node_Id; + E_Name : Entity_Id; + P_Name : Entity_Id; + P_Spec : Node_Id; + + begin + P := Unit (Parent_Spec (Lib_Unit)); + P_Name := Get_Parent_Entity (P); + + if Etype (P_Name) = Any_Type then + return; + end if; + + if Ekind (P_Name) = E_Generic_Package + and then not Nkind_In (Lib_Unit, N_Generic_Subprogram_Declaration, + N_Generic_Package_Declaration) + and then Nkind (Lib_Unit) not in N_Generic_Renaming_Declaration + then + Error_Msg_N + ("child of a generic package must be a generic unit", Lib_Unit); + + elsif not Is_Package_Or_Generic_Package (P_Name) then + Error_Msg_N + ("parent unit must be package or generic package", Lib_Unit); + raise Unrecoverable_Error; + + elsif Present (Renamed_Object (P_Name)) then + Error_Msg_N ("parent unit cannot be a renaming", Lib_Unit); + raise Unrecoverable_Error; + + -- Verify that a child of an instance is itself an instance, or the + -- renaming of one. Given that an instance that is a unit is replaced + -- with a package declaration, check against the original node. The + -- parent may be currently being instantiated, in which case it appears + -- as a declaration, but the generic_parent is already established + -- indicating that we deal with an instance. + + elsif Nkind (Original_Node (P)) = N_Package_Instantiation then + if Nkind (Lib_Unit) in N_Renaming_Declaration + or else Nkind (Original_Node (Lib_Unit)) in N_Generic_Instantiation + or else + (Nkind (Lib_Unit) = N_Package_Declaration + and then Present (Generic_Parent (Specification (Lib_Unit)))) + then + null; + else + Error_Msg_N + ("child of an instance must be an instance or renaming", + Lib_Unit); + end if; + end if; + + -- This is the recursive call that ensures all parents are loaded + + if Is_Child_Spec (P) then + Install_Parents (P, + Is_Private or else Private_Present (Parent (Lib_Unit))); + end if; + + -- Now we can install the context for this parent + + Install_Context_Clauses (Parent_Spec (Lib_Unit)); + Install_Limited_Context_Clauses (Parent_Spec (Lib_Unit)); + Install_Siblings (P_Name, Parent (Lib_Unit)); + + -- The child unit is in the declarative region of the parent. The parent + -- must therefore appear in the scope stack and be visible, as when + -- compiling the corresponding body. If the child unit is private or it + -- is a package body, private declarations must be accessible as well. + -- Use declarations in the parent must also be installed. Finally, other + -- child units of the same parent that are in the context are + -- immediately visible. + + -- Find entity for compilation unit, and set its private descendant + -- status as needed. Indicate that it is a compilation unit, which is + -- redundant in general, but needed if this is a generated child spec + -- for a child body without previous spec. + + E_Name := Defining_Entity (Lib_Unit); + + Set_Is_Child_Unit (E_Name); + Set_Is_Compilation_Unit (E_Name); + + Set_Is_Private_Descendant (E_Name, + Is_Private_Descendant (P_Name) + or else Private_Present (Parent (Lib_Unit))); + + P_Spec := Package_Specification (P_Name); + Push_Scope (P_Name); + + -- Save current visibility of unit + + Scope_Stack.Table (Scope_Stack.Last).Previous_Visibility := + Is_Immediately_Visible (P_Name); + Set_Is_Immediately_Visible (P_Name); + Install_Visible_Declarations (P_Name); + Set_Use (Visible_Declarations (P_Spec)); + + -- If the parent is a generic unit, its formal part may contain formal + -- packages and use clauses for them. + + if Ekind (P_Name) = E_Generic_Package then + Set_Use (Generic_Formal_Declarations (Parent (P_Spec))); + end if; + + if Is_Private or else Private_Present (Parent (Lib_Unit)) then + Install_Private_Declarations (P_Name); + Install_Private_With_Clauses (P_Name); + Set_Use (Private_Declarations (P_Spec)); + end if; + end Install_Parents; + + ---------------------------------- + -- Install_Private_With_Clauses -- + ---------------------------------- + + procedure Install_Private_With_Clauses (P : Entity_Id) is + Decl : constant Node_Id := Unit_Declaration_Node (P); + Item : Node_Id; + + begin + if Debug_Flag_I then + Write_Str ("install private with clauses of "); + Write_Name (Chars (P)); + Write_Eol; + end if; + + if Nkind (Parent (Decl)) = N_Compilation_Unit then + Item := First (Context_Items (Parent (Decl))); + while Present (Item) loop + if Nkind (Item) = N_With_Clause + and then Private_Present (Item) + then + -- If the unit is an ancestor of the current one, it is the + -- case of a private limited with clause on a child unit, and + -- the compilation of one of its descendants, In that case the + -- limited view is errelevant. + + if Limited_Present (Item) then + if not Limited_View_Installed (Item) + and then + not Is_Ancestor_Unit (Library_Unit (Item), + Cunit (Current_Sem_Unit)) + then + Install_Limited_Withed_Unit (Item); + end if; + else + Install_Withed_Unit (Item, Private_With_OK => True); + end if; + end if; + + Next (Item); + end loop; + end if; + end Install_Private_With_Clauses; + + ---------------------- + -- Install_Siblings -- + ---------------------- + + procedure Install_Siblings (U_Name : Entity_Id; N : Node_Id) is + Item : Node_Id; + Id : Entity_Id; + Prev : Entity_Id; + + begin + -- Iterate over explicit with clauses, and check whether the scope of + -- each entity is an ancestor of the current unit, in which case it is + -- immediately visible. + + Item := First (Context_Items (N)); + while Present (Item) loop + + -- Do not install private_with_clauses declaration, unless unit + -- is itself a private child unit, or is a body. Note that for a + -- subprogram body the private_with_clause does not take effect until + -- after the specification. + + if Nkind (Item) /= N_With_Clause + or else Implicit_With (Item) + or else Limited_Present (Item) + or else Error_Posted (Item) + then + null; + + elsif not Private_Present (Item) + or else Private_Present (N) + or else Nkind (Unit (N)) = N_Package_Body + then + Id := Entity (Name (Item)); + + if Is_Child_Unit (Id) + and then Is_Ancestor_Package (Scope (Id), U_Name) + then + Set_Is_Immediately_Visible (Id); + + -- Check for the presence of another unit in the context that + -- may be inadvertently hidden by the child. + + Prev := Current_Entity (Id); + + if Present (Prev) + and then Is_Immediately_Visible (Prev) + and then not Is_Child_Unit (Prev) + then + declare + Clause : Node_Id; + + begin + Clause := First (Context_Items (N)); + while Present (Clause) loop + if Nkind (Clause) = N_With_Clause + and then Entity (Name (Clause)) = Prev + then + Error_Msg_NE + ("child unit& hides compilation unit " & + "with the same name??", + Name (Item), Id); + exit; + end if; + + Next (Clause); + end loop; + end; + end if; + + -- The With_Clause may be on a grand-child or one of its further + -- descendants, which makes a child immediately visible. Examine + -- ancestry to determine whether such a child exists. For example, + -- if current unit is A.C, and with_clause is on A.X.Y.Z, then X + -- is immediately visible. + + elsif Is_Child_Unit (Id) then + declare + Par : Entity_Id; + + begin + Par := Scope (Id); + while Is_Child_Unit (Par) loop + if Is_Ancestor_Package (Scope (Par), U_Name) then + Set_Is_Immediately_Visible (Par); + exit; + end if; + + Par := Scope (Par); + end loop; + end; + end if; + + -- If the item is a private with-clause on a child unit, the parent + -- may have been installed already, but the child unit must remain + -- invisible until installed in a private part or body, unless there + -- is already a regular with_clause for it in the current unit. + + elsif Private_Present (Item) then + Id := Entity (Name (Item)); + + if Is_Child_Unit (Id) then + declare + Clause : Node_Id; + + function In_Context return Boolean; + -- Scan context of current unit, to check whether there is + -- a with_clause on the same unit as a private with-clause + -- on a parent, in which case child unit is visible. If the + -- unit is a grand-child, the same applies to its parent. + + ---------------- + -- In_Context -- + ---------------- + + function In_Context return Boolean is + begin + Clause := + First (Context_Items (Cunit (Current_Sem_Unit))); + while Present (Clause) loop + if Nkind (Clause) = N_With_Clause + and then Comes_From_Source (Clause) + and then Is_Entity_Name (Name (Clause)) + and then not Private_Present (Clause) + then + if Entity (Name (Clause)) = Id + or else + (Nkind (Name (Clause)) = N_Expanded_Name + and then Entity (Prefix (Name (Clause))) = Id) + then + return True; + end if; + end if; + + Next (Clause); + end loop; + + return False; + end In_Context; + + begin + Set_Is_Visible_Lib_Unit (Id, In_Context); + end; + end if; + end if; + + Next (Item); + end loop; + end Install_Siblings; + + --------------------------------- + -- Install_Limited_Withed_Unit -- + --------------------------------- + + procedure Install_Limited_Withed_Unit (N : Node_Id) is + P_Unit : constant Entity_Id := Unit (Library_Unit (N)); + E : Entity_Id; + P : Entity_Id; + Is_Child_Package : Boolean := False; + Lim_Header : Entity_Id; + Lim_Typ : Entity_Id; + + procedure Check_Body_Required; + -- A unit mentioned in a limited with_clause may not be mentioned in + -- a regular with_clause, but must still be included in the current + -- partition. We need to determine whether the unit needs a body, so + -- that the binder can determine the name of the file to be compiled. + -- Checking whether a unit needs a body can be done without semantic + -- analysis, by examining the nature of the declarations in the package. + + function Has_Limited_With_Clause + (C_Unit : Entity_Id; + Pack : Entity_Id) return Boolean; + -- Determine whether any package in the ancestor chain starting with + -- C_Unit has a limited with clause for package Pack. + + function Is_Visible_Through_Renamings (P : Entity_Id) return Boolean; + -- Check if some package installed though normal with-clauses has a + -- renaming declaration of package P. AARM 10.1.2(21/2). + + ------------------------- + -- Check_Body_Required -- + ------------------------- + + procedure Check_Body_Required is + PA : constant List_Id := + Pragmas_After (Aux_Decls_Node (Parent (P_Unit))); + + procedure Check_Declarations (Spec : Node_Id); + -- Recursive procedure that does the work and checks nested packages + + ------------------------ + -- Check_Declarations -- + ------------------------ + + procedure Check_Declarations (Spec : Node_Id) is + Decl : Node_Id; + Incomplete_Decls : constant Elist_Id := New_Elmt_List; + + Subp_List : constant Elist_Id := New_Elmt_List; + + procedure Check_Pragma_Import (P : Node_Id); + -- If a pragma import applies to a previous subprogram, the + -- enclosing unit may not need a body. The processing is syntactic + -- and does not require a declaration to be analyzed. The code + -- below also handles pragma Import when applied to a subprogram + -- that renames another. In this case the pragma applies to the + -- renamed entity. + -- + -- Chains of multiple renames are not handled by the code below. + -- It is probably impossible to handle all cases without proper + -- name resolution. In such cases the algorithm is conservative + -- and will indicate that a body is needed??? + + ------------------------- + -- Check_Pragma_Import -- + ------------------------- + + procedure Check_Pragma_Import (P : Node_Id) is + Arg : Node_Id; + Prev_Id : Elmt_Id; + Subp_Id : Elmt_Id; + Imported : Node_Id; + + procedure Remove_Homonyms (E : Node_Id); + -- Make one pass over list of subprograms. Called again if + -- subprogram is a renaming. E is known to be an identifier. + + --------------------- + -- Remove_Homonyms -- + --------------------- + + procedure Remove_Homonyms (E : Node_Id) is + R : Entity_Id := Empty; + -- Name of renamed entity, if any + + begin + Subp_Id := First_Elmt (Subp_List); + while Present (Subp_Id) loop + if Chars (Node (Subp_Id)) = Chars (E) then + if Nkind (Parent (Parent (Node (Subp_Id)))) + /= N_Subprogram_Renaming_Declaration + then + Prev_Id := Subp_Id; + Next_Elmt (Subp_Id); + Remove_Elmt (Subp_List, Prev_Id); + else + R := Name (Parent (Parent (Node (Subp_Id)))); + exit; + end if; + else + Next_Elmt (Subp_Id); + end if; + end loop; + + if Present (R) then + if Nkind (R) = N_Identifier then + Remove_Homonyms (R); + + elsif Nkind (R) = N_Selected_Component then + Remove_Homonyms (Selector_Name (R)); + + -- Renaming of attribute + + else + null; + end if; + end if; + end Remove_Homonyms; + + -- Start of processing for Check_Pragma_Import + + begin + -- Find name of entity in Import pragma. We have not analyzed + -- the construct, so we must guard against syntax errors. + + Arg := Next (First (Pragma_Argument_Associations (P))); + + if No (Arg) + or else Nkind (Expression (Arg)) /= N_Identifier + then + return; + else + Imported := Expression (Arg); + end if; + + Remove_Homonyms (Imported); + end Check_Pragma_Import; + + -- Start of processing for Check_Declarations + + begin + -- Search for Elaborate Body pragma + + Decl := First (Visible_Declarations (Spec)); + while Present (Decl) + and then Nkind (Decl) = N_Pragma + loop + if Get_Pragma_Id (Decl) = Pragma_Elaborate_Body then + Set_Body_Required (Library_Unit (N)); + return; + end if; + + Next (Decl); + end loop; + + -- Look for declarations that require the presence of a body. We + -- have already skipped pragmas at the start of the list. + + while Present (Decl) loop + + -- Subprogram that comes from source means body may be needed. + -- Save for subsequent examination of import pragmas. + + if Comes_From_Source (Decl) + and then (Nkind_In (Decl, N_Subprogram_Declaration, + N_Subprogram_Renaming_Declaration, + N_Generic_Subprogram_Declaration)) + then + Append_Elmt (Defining_Entity (Decl), Subp_List); + + -- Package declaration of generic package declaration. We need + -- to recursively examine nested declarations. + + elsif Nkind_In (Decl, N_Package_Declaration, + N_Generic_Package_Declaration) + then + Check_Declarations (Specification (Decl)); + + elsif Nkind (Decl) = N_Pragma + and then Pragma_Name (Decl) = Name_Import + then + Check_Pragma_Import (Decl); + end if; + + Next (Decl); + end loop; + + -- Same set of tests for private part. In addition to subprograms + -- detect the presence of Taft Amendment types (incomplete types + -- completed in the body). + + Decl := First (Private_Declarations (Spec)); + while Present (Decl) loop + if Comes_From_Source (Decl) + and then (Nkind_In (Decl, N_Subprogram_Declaration, + N_Subprogram_Renaming_Declaration, + N_Generic_Subprogram_Declaration)) + then + Append_Elmt (Defining_Entity (Decl), Subp_List); + + elsif Nkind_In (Decl, N_Package_Declaration, + N_Generic_Package_Declaration) + then + Check_Declarations (Specification (Decl)); + + -- Collect incomplete type declarations for separate pass + + elsif Nkind (Decl) = N_Incomplete_Type_Declaration then + Append_Elmt (Decl, Incomplete_Decls); + + elsif Nkind (Decl) = N_Pragma + and then Pragma_Name (Decl) = Name_Import + then + Check_Pragma_Import (Decl); + end if; + + Next (Decl); + end loop; + + -- Now check incomplete declarations to locate Taft amendment + -- types. This can be done by examining the defining identifiers + -- of type declarations without real semantic analysis. + + declare + Inc : Elmt_Id; + + begin + Inc := First_Elmt (Incomplete_Decls); + while Present (Inc) loop + Decl := Next (Node (Inc)); + while Present (Decl) loop + if Nkind (Decl) = N_Full_Type_Declaration + and then Chars (Defining_Identifier (Decl)) = + Chars (Defining_Identifier (Node (Inc))) + then + exit; + end if; + + Next (Decl); + end loop; + + -- If no completion, this is a TAT, and a body is needed + + if No (Decl) then + Set_Body_Required (Library_Unit (N)); + return; + end if; + + Next_Elmt (Inc); + end loop; + end; + + -- Finally, check whether there are subprograms that still require + -- a body, i.e. are not renamings or null. + + if not Is_Empty_Elmt_List (Subp_List) then + declare + Subp_Id : Elmt_Id; + Spec : Node_Id; + + begin + Subp_Id := First_Elmt (Subp_List); + Spec := Parent (Node (Subp_Id)); + + while Present (Subp_Id) loop + if Nkind (Parent (Spec)) + = N_Subprogram_Renaming_Declaration + then + null; + + elsif Nkind (Spec) = N_Procedure_Specification + and then Null_Present (Spec) + then + null; + + else + Set_Body_Required (Library_Unit (N)); + return; + end if; + + Next_Elmt (Subp_Id); + end loop; + end; + end if; + end Check_Declarations; + + -- Start of processing for Check_Body_Required + + begin + -- If this is an imported package (Java and CIL usage) no body is + -- needed. Scan list of pragmas that may follow a compilation unit + -- to look for a relevant pragma Import. + + if Present (PA) then + declare + Prag : Node_Id; + + begin + Prag := First (PA); + while Present (Prag) loop + if Nkind (Prag) = N_Pragma + and then Get_Pragma_Id (Prag) = Pragma_Import + then + return; + end if; + + Next (Prag); + end loop; + end; + end if; + + Check_Declarations (Specification (P_Unit)); + end Check_Body_Required; + + ----------------------------- + -- Has_Limited_With_Clause -- + ----------------------------- + + function Has_Limited_With_Clause + (C_Unit : Entity_Id; + Pack : Entity_Id) return Boolean + is + Par : Entity_Id; + Par_Unit : Node_Id; + + begin + Par := C_Unit; + while Present (Par) loop + if Ekind (Par) /= E_Package then + exit; + end if; + + -- Retrieve the Compilation_Unit node for Par and determine if + -- its context clauses contain a limited with for Pack. + + Par_Unit := Parent (Parent (Parent (Par))); + + if Nkind (Par_Unit) = N_Package_Declaration then + Par_Unit := Parent (Par_Unit); + end if; + + if Has_With_Clause (Par_Unit, Pack, True) then + return True; + end if; + + -- If there are more ancestors, climb up the tree, otherwise we + -- are done. + + if Is_Child_Unit (Par) then + Par := Scope (Par); + else + exit; + end if; + end loop; + + return False; + end Has_Limited_With_Clause; + + ---------------------------------- + -- Is_Visible_Through_Renamings -- + ---------------------------------- + + function Is_Visible_Through_Renamings (P : Entity_Id) return Boolean is + Kind : constant Node_Kind := + Nkind (Unit (Cunit (Current_Sem_Unit))); + Aux_Unit : Node_Id; + Item : Node_Id; + Decl : Entity_Id; + + begin + -- Example of the error detected by this subprogram: + + -- package P is + -- type T is ... + -- end P; + + -- with P; + -- package Q is + -- package Ren_P renames P; + -- end Q; + + -- with Q; + -- package R is ... + + -- limited with P; -- ERROR + -- package R.C is ... + + Aux_Unit := Cunit (Current_Sem_Unit); + + loop + Item := First (Context_Items (Aux_Unit)); + while Present (Item) loop + if Nkind (Item) = N_With_Clause + and then not Limited_Present (Item) + and then Nkind (Unit (Library_Unit (Item))) = + N_Package_Declaration + then + Decl := + First (Visible_Declarations + (Specification (Unit (Library_Unit (Item))))); + while Present (Decl) loop + if Nkind (Decl) = N_Package_Renaming_Declaration + and then Entity (Name (Decl)) = P + then + -- Generate the error message only if the current unit + -- is a package declaration; in case of subprogram + -- bodies and package bodies we just return True to + -- indicate that the limited view must not be + -- installed. + + if Kind = N_Package_Declaration then + Error_Msg_N + ("simultaneous visibility of the limited and " & + "unlimited views not allowed", N); + Error_Msg_Sloc := Sloc (Item); + Error_Msg_NE + ("\\ unlimited view of & visible through the " & + "context clause #", N, P); + Error_Msg_Sloc := Sloc (Decl); + Error_Msg_NE ("\\ and the renaming #", N, P); + end if; + + return True; + end if; + + Next (Decl); + end loop; + end if; + + Next (Item); + end loop; + + -- If it is a body not acting as spec, follow pointer to the + -- corresponding spec, otherwise follow pointer to parent spec. + + if Present (Library_Unit (Aux_Unit)) + and then Nkind_In (Unit (Aux_Unit), + N_Package_Body, N_Subprogram_Body) + then + if Aux_Unit = Library_Unit (Aux_Unit) then + + -- Aux_Unit is a body that acts as a spec. Clause has + -- already been flagged as illegal. + + return False; + + else + Aux_Unit := Library_Unit (Aux_Unit); + end if; + + else + Aux_Unit := Parent_Spec (Unit (Aux_Unit)); + end if; + + exit when No (Aux_Unit); + end loop; + + return False; + end Is_Visible_Through_Renamings; + + -- Start of processing for Install_Limited_Withed_Unit + + begin + pragma Assert (not Limited_View_Installed (N)); + + -- In case of limited with_clause on subprograms, generics, instances, + -- or renamings, the corresponding error was previously posted and we + -- have nothing to do here. If the file is missing altogether, it has + -- no source location. + + if Nkind (P_Unit) /= N_Package_Declaration + or else Sloc (P_Unit) = No_Location + then + return; + end if; + + P := Defining_Unit_Name (Specification (P_Unit)); + + -- Handle child packages + + if Nkind (P) = N_Defining_Program_Unit_Name then + Is_Child_Package := True; + P := Defining_Identifier (P); + end if; + + -- Do not install the limited-view if the context of the unit is already + -- available through a regular with clause. + + if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body + and then Has_With_Clause (Cunit (Current_Sem_Unit), P) + then + return; + end if; + + -- Do not install the limited-view if the full-view is already visible + -- through renaming declarations. + + if Is_Visible_Through_Renamings (P) then + return; + end if; + + -- Do not install the limited view if this is the unit being analyzed. + -- This unusual case will happen when a unit has a limited_with clause + -- on one of its children. The compilation of the child forces the load + -- of the parent which tries to install the limited view of the child + -- again. Installing the limited view must also be disabled when + -- compiling the body of the child unit. + + if P = Cunit_Entity (Current_Sem_Unit) + or else (Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body + and then P = Main_Unit_Entity + and then Is_Ancestor_Unit + (Cunit (Main_Unit), Cunit (Current_Sem_Unit))) + then + return; + end if; + + -- This scenario is similar to the one above, the difference is that the + -- compilation of sibling Par.Sib forces the load of parent Par which + -- tries to install the limited view of Lim_Pack [1]. However Par.Sib + -- has a with clause for Lim_Pack [2] in its body, and thus needs the + -- non-limited views of all entities from Lim_Pack. + + -- limited with Lim_Pack; -- [1] + -- package Par is ... package Lim_Pack is ... + + -- with Lim_Pack; -- [2] + -- package Par.Sib is ... package body Par.Sib is ... + + -- In this case Main_Unit_Entity is the spec of Par.Sib and Current_ + -- Sem_Unit is the body of Par.Sib. + + if Ekind (P) = E_Package + and then Ekind (Main_Unit_Entity) = E_Package + and then Is_Child_Unit (Main_Unit_Entity) + + -- The body has a regular with clause + + and then Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body + and then Has_With_Clause (Cunit (Current_Sem_Unit), P) + + -- One of the ancestors has a limited with clause + + and then Nkind (Parent (Parent (Main_Unit_Entity))) = + N_Package_Specification + and then Has_Limited_With_Clause (Scope (Main_Unit_Entity), P) + then + return; + end if; + + -- A common use of the limited-with is to have a limited-with in the + -- package spec, and a normal with in its package body. For example: + + -- limited with X; -- [1] + -- package A is ... + + -- with X; -- [2] + -- package body A is ... + + -- The compilation of A's body installs the context clauses found at [2] + -- and then the context clauses of its specification (found at [1]). As + -- a consequence, at [1] the specification of X has been analyzed and it + -- is immediately visible. According to the semantics of limited-with + -- context clauses we don't install the limited view because the full + -- view of X supersedes its limited view. + + if Analyzed (P_Unit) + and then + (Is_Immediately_Visible (P) + or else (Is_Child_Package and then Is_Visible_Lib_Unit (P))) + then + + -- The presence of both the limited and the analyzed nonlimited view + -- may also be an error, such as an illegal context for a limited + -- with_clause. In that case, do not process the context item at all. + + if Error_Posted (N) then + return; + end if; + + if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then + declare + Item : Node_Id; + begin + Item := First (Context_Items (Cunit (Current_Sem_Unit))); + while Present (Item) loop + if Nkind (Item) = N_With_Clause + and then Comes_From_Source (Item) + and then Entity (Name (Item)) = P + then + return; + end if; + + Next (Item); + end loop; + end; + + -- If this is a child body, assume that the nonlimited with_clause + -- appears in an ancestor. Could be refined ??? + + if Is_Child_Unit + (Defining_Entity + (Unit (Library_Unit (Cunit (Current_Sem_Unit))))) + then + return; + end if; + + else + + -- If in package declaration, nonlimited view brought in from + -- parent unit or some error condition. + + return; + end if; + end if; + + if Debug_Flag_I then + Write_Str ("install limited view of "); + Write_Name (Chars (P)); + Write_Eol; + end if; + + -- If the unit has not been analyzed and the limited view has not been + -- already installed then we install it. + + if not Analyzed (P_Unit) then + if not In_Chain (P) then + + -- Minimum decoration + + Set_Ekind (P, E_Package); + Set_Etype (P, Standard_Void_Type); + Set_Scope (P, Standard_Standard); + Set_Is_Visible_Lib_Unit (P); + + if Is_Child_Package then + Set_Is_Child_Unit (P); + Set_Scope (P, Defining_Entity (Unit (Parent_Spec (P_Unit)))); + end if; + + -- Place entity on visibility structure + + Set_Homonym (P, Current_Entity (P)); + Set_Current_Entity (P); + + if Debug_Flag_I then + Write_Str (" (homonym) chain "); + Write_Name (Chars (P)); + Write_Eol; + end if; + + -- Install the incomplete view. The first element of the limited + -- view is a header (an E_Package entity) used to reference the + -- first shadow entity in the private part of the package. + + Lim_Header := Limited_View (P); + Lim_Typ := First_Entity (Lim_Header); + + while Present (Lim_Typ) + and then Lim_Typ /= First_Private_Entity (Lim_Header) + loop + Set_Homonym (Lim_Typ, Current_Entity (Lim_Typ)); + Set_Current_Entity (Lim_Typ); + + if Debug_Flag_I then + Write_Str (" (homonym) chain "); + Write_Name (Chars (Lim_Typ)); + Write_Eol; + end if; + + Next_Entity (Lim_Typ); + end loop; + end if; + + -- If the unit appears in a previous regular with_clause, the regular + -- entities of the public part of the withed package must be replaced + -- by the shadow ones. + + -- This code must be kept synchronized with the code that replaces the + -- shadow entities by the real entities (see body of Remove_Limited + -- With_Clause); otherwise the contents of the homonym chains are not + -- consistent. + + else + -- Hide all the type entities of the public part of the package to + -- avoid its usage. This is needed to cover all the subtype decla- + -- rations because we do not remove them from the homonym chain. + + E := First_Entity (P); + while Present (E) and then E /= First_Private_Entity (P) loop + if Is_Type (E) then + Set_Was_Hidden (E, Is_Hidden (E)); + Set_Is_Hidden (E); + end if; + + Next_Entity (E); + end loop; + + -- Replace the real entities by the shadow entities of the limited + -- view. The first element of the limited view is a header that is + -- used to reference the first shadow entity in the private part + -- of the package. Successive elements are the limited views of the + -- type (including regular incomplete types) declared in the package. + + Lim_Header := Limited_View (P); + + Lim_Typ := First_Entity (Lim_Header); + while Present (Lim_Typ) + and then Lim_Typ /= First_Private_Entity (Lim_Header) + loop + pragma Assert (not In_Chain (Lim_Typ)); + + -- Do not unchain nested packages and child units + + if Ekind (Lim_Typ) /= E_Package + and then not Is_Child_Unit (Lim_Typ) + then + declare + Prev : Entity_Id; + + begin + Prev := Current_Entity (Lim_Typ); + E := Prev; + + -- Replace E in the homonyms list, so that the limited view + -- becomes available. + + -- If the non-limited view is a record with an anonymous + -- self-referential component, the analysis of the record + -- declaration creates an incomplete type with the same name + -- in order to define an internal access type. The visible + -- entity is now the incomplete type, and that is the one to + -- replace in the visibility structure. + + if E = Non_Limited_View (Lim_Typ) + or else + (Ekind (E) = E_Incomplete_Type + and then Full_View (E) = Non_Limited_View (Lim_Typ)) + then + Set_Homonym (Lim_Typ, Homonym (Prev)); + Set_Current_Entity (Lim_Typ); + + else + loop + E := Homonym (Prev); + + -- E may have been removed when installing a previous + -- limited_with_clause. + + exit when No (E); + exit when E = Non_Limited_View (Lim_Typ); + Prev := Homonym (Prev); + end loop; + + if Present (E) then + Set_Homonym (Lim_Typ, Homonym (Homonym (Prev))); + Set_Homonym (Prev, Lim_Typ); + end if; + end if; + end; + + if Debug_Flag_I then + Write_Str (" (homonym) chain "); + Write_Name (Chars (Lim_Typ)); + Write_Eol; + end if; + end if; + + Next_Entity (Lim_Typ); + end loop; + end if; + + -- The package must be visible while the limited-with clause is active + -- because references to the type P.T must resolve in the usual way. + -- In addition, we remember that the limited-view has been installed to + -- uninstall it at the point of context removal. + + Set_Is_Immediately_Visible (P); + Set_Limited_View_Installed (N); + + -- If unit has not been analyzed in some previous context, check + -- (imperfectly ???) whether it might need a body. + + if not Analyzed (P_Unit) then + Check_Body_Required; + end if; + + -- If the package in the limited_with clause is a child unit, the clause + -- is unanalyzed and appears as a selected component. Recast it as an + -- expanded name so that the entity can be properly set. Use entity of + -- parent, if available, for higher ancestors in the name. + + if Nkind (Name (N)) = N_Selected_Component then + declare + Nam : Node_Id; + Ent : Entity_Id; + + begin + Nam := Name (N); + Ent := P; + while Nkind (Nam) = N_Selected_Component + and then Present (Ent) + loop + Change_Selected_Component_To_Expanded_Name (Nam); + + -- Set entity of parent identifiers if the unit is a child + -- unit. This ensures that the tree is properly formed from + -- semantic point of view (e.g. for ASIS queries). The unit + -- entities are not fully analyzed, so we need to follow unit + -- links in the tree. + + Set_Entity (Nam, Ent); + + Nam := Prefix (Nam); + Ent := + Defining_Entity + (Unit (Parent_Spec (Unit_Declaration_Node (Ent)))); + + -- Set entity of last ancestor + + if Nkind (Nam) = N_Identifier then + Set_Entity (Nam, Ent); + end if; + end loop; + end; + end if; + + Set_Entity (Name (N), P); + Set_From_Limited_With (P); + end Install_Limited_Withed_Unit; + + ------------------------- + -- Install_Withed_Unit -- + ------------------------- + + procedure Install_Withed_Unit + (With_Clause : Node_Id; + Private_With_OK : Boolean := False) + is + Uname : constant Entity_Id := Entity (Name (With_Clause)); + P : constant Entity_Id := Scope (Uname); + + begin + -- Ada 2005 (AI-262): Do not install the private withed unit if we are + -- compiling a package declaration and the Private_With_OK flag was not + -- set by the caller. These declarations will be installed later (before + -- analyzing the private part of the package). + + if Private_Present (With_Clause) + and then Nkind (Unit (Parent (With_Clause))) = N_Package_Declaration + and then not (Private_With_OK) + then + return; + end if; + + if Debug_Flag_I then + if Private_Present (With_Clause) then + Write_Str ("install private withed unit "); + else + Write_Str ("install withed unit "); + end if; + + Write_Name (Chars (Uname)); + Write_Eol; + end if; + + -- We do not apply the restrictions to an internal unit unless we are + -- compiling the internal unit as a main unit. This check is also + -- skipped for dummy units (for missing packages). + + if Sloc (Uname) /= No_Location + and then (not Is_Internal_File_Name (Unit_File_Name (Current_Sem_Unit)) + or else Current_Sem_Unit = Main_Unit) + then + Check_Restricted_Unit + (Unit_Name (Get_Source_Unit (Uname)), With_Clause); + end if; + + if P /= Standard_Standard then + + -- If the unit is not analyzed after analysis of the with clause and + -- it is an instantiation then it awaits a body and is the main unit. + -- Its appearance in the context of some other unit indicates a + -- circular dependency (DEC suite perversity). + + if not Analyzed (Uname) + and then Nkind (Parent (Uname)) = N_Package_Instantiation + then + Error_Msg_N + ("instantiation depends on itself", Name (With_Clause)); + + elsif not Is_Visible_Lib_Unit (Uname) then + + -- Abandon processing in case of previous errors + + if No (Scope (Uname)) then + Check_Error_Detected; + return; + end if; + + Set_Is_Visible_Lib_Unit (Uname); + + -- If the unit is a wrapper package for a compilation unit that is + -- a subprogrm instance, indicate that the instance itself is a + -- visible unit. This is necessary if the instance is inlined. + + if Is_Wrapper_Package (Uname) then + Set_Is_Visible_Lib_Unit (Related_Instance (Uname)); + end if; + + -- If the child unit appears in the context of its parent, it is + -- immediately visible. + + if In_Open_Scopes (Scope (Uname)) then + Set_Is_Immediately_Visible (Uname); + end if; + + if Is_Generic_Instance (Uname) + and then Ekind (Uname) in Subprogram_Kind + then + -- Set flag as well on the visible entity that denotes the + -- instance, which renames the current one. + + Set_Is_Visible_Lib_Unit + (Related_Instance + (Defining_Entity (Unit (Library_Unit (With_Clause))))); + end if; + + -- The parent unit may have been installed already, and may have + -- appeared in a use clause. + + if In_Use (Scope (Uname)) then + Set_Is_Potentially_Use_Visible (Uname); + end if; + + Set_Context_Installed (With_Clause); + end if; + + elsif not Is_Immediately_Visible (Uname) then + Set_Is_Visible_Lib_Unit (Uname); + + if not Private_Present (With_Clause) or else Private_With_OK then + Set_Is_Immediately_Visible (Uname); + end if; + + Set_Context_Installed (With_Clause); + end if; + + -- A with-clause overrides a with-type clause: there are no restric- + -- tions on the use of package entities. + + if Ekind (Uname) = E_Package then + Set_From_Limited_With (Uname, False); + end if; + + -- Ada 2005 (AI-377): it is illegal for a with_clause to name a child + -- unit if there is a visible homograph for it declared in the same + -- declarative region. This pathological case can only arise when an + -- instance I1 of a generic unit G1 has an explicit child unit I1.G2, + -- G1 has a generic child also named G2, and the context includes with_ + -- clauses for both I1.G2 and for G1.G2, making an implicit declaration + -- of I1.G2 visible as well. If the child unit is named Standard, do + -- not apply the check to the Standard package itself. + + if Is_Child_Unit (Uname) + and then Is_Visible_Lib_Unit (Uname) + and then Ada_Version >= Ada_2005 + then + declare + Decl1 : constant Node_Id := Unit_Declaration_Node (P); + Decl2 : Node_Id; + P2 : Entity_Id; + U2 : Entity_Id; + + begin + U2 := Homonym (Uname); + while Present (U2) and then U2 /= Standard_Standard loop + P2 := Scope (U2); + Decl2 := Unit_Declaration_Node (P2); + + if Is_Child_Unit (U2) and then Is_Visible_Lib_Unit (U2) then + if Is_Generic_Instance (P) + and then Nkind (Decl1) = N_Package_Declaration + and then Generic_Parent (Specification (Decl1)) = P2 + then + Error_Msg_N ("illegal with_clause", With_Clause); + Error_Msg_N + ("\child unit has visible homograph" & + " (RM 8.3(26), 10.1.1(19))", + With_Clause); + exit; + + elsif Is_Generic_Instance (P2) + and then Nkind (Decl2) = N_Package_Declaration + and then Generic_Parent (Specification (Decl2)) = P + then + -- With_clause for child unit of instance appears before + -- in the context. We want to place the error message on + -- it, not on the generic child unit itself. + + declare + Prev_Clause : Node_Id; + + begin + Prev_Clause := First (List_Containing (With_Clause)); + while Entity (Name (Prev_Clause)) /= U2 loop + Next (Prev_Clause); + end loop; + + pragma Assert (Present (Prev_Clause)); + Error_Msg_N ("illegal with_clause", Prev_Clause); + Error_Msg_N + ("\child unit has visible homograph" & + " (RM 8.3(26), 10.1.1(19))", + Prev_Clause); + exit; + end; + end if; + end if; + + U2 := Homonym (U2); + end loop; + end; + end if; + end Install_Withed_Unit; + + ------------------- + -- Is_Child_Spec -- + ------------------- + + function Is_Child_Spec (Lib_Unit : Node_Id) return Boolean is + K : constant Node_Kind := Nkind (Lib_Unit); + + begin + return (K in N_Generic_Declaration or else + K in N_Generic_Instantiation or else + K in N_Generic_Renaming_Declaration or else + K = N_Package_Declaration or else + K = N_Package_Renaming_Declaration or else + K = N_Subprogram_Declaration or else + K = N_Subprogram_Renaming_Declaration) + and then Present (Parent_Spec (Lib_Unit)); + end Is_Child_Spec; + + ------------------------------------ + -- Is_Legal_Shadow_Entity_In_Body -- + ------------------------------------ + + function Is_Legal_Shadow_Entity_In_Body (T : Entity_Id) return Boolean is + C_Unit : constant Node_Id := Cunit (Current_Sem_Unit); + begin + return Nkind (Unit (C_Unit)) = N_Package_Body + and then + Has_With_Clause + (C_Unit, Cunit_Entity (Get_Source_Unit (Non_Limited_View (T)))); + end Is_Legal_Shadow_Entity_In_Body; + + ---------------------- + -- Is_Ancestor_Unit -- + ---------------------- + + function Is_Ancestor_Unit (U1 : Node_Id; U2 : Node_Id) return Boolean is + E1 : constant Entity_Id := Defining_Entity (Unit (U1)); + E2 : Entity_Id; + begin + if Nkind_In (Unit (U2), N_Package_Body, N_Subprogram_Body) then + E2 := Defining_Entity (Unit (Library_Unit (U2))); + return Is_Ancestor_Package (E1, E2); + else + return False; + end if; + end Is_Ancestor_Unit; + + ----------------------- + -- Load_Needed_Body -- + ----------------------- + + -- N is a generic unit named in a with clause, or else it is a unit that + -- contains a generic unit or an inlined function. In order to perform an + -- instantiation, the body of the unit must be present. If the unit itself + -- is generic, we assume that an instantiation follows, and load & analyze + -- the body unconditionally. This forces analysis of the spec as well. + + -- If the unit is not generic, but contains a generic unit, it is loaded on + -- demand, at the point of instantiation (see ch12). + + procedure Load_Needed_Body + (N : Node_Id; + OK : out Boolean; + Do_Analyze : Boolean := True) + is + Body_Name : Unit_Name_Type; + Unum : Unit_Number_Type; + + Save_Style_Check : constant Boolean := Opt.Style_Check; + -- The loading and analysis is done with style checks off + + begin + if not GNAT_Mode then + Style_Check := False; + end if; + + Body_Name := Get_Body_Name (Get_Unit_Name (Unit (N))); + Unum := + Load_Unit + (Load_Name => Body_Name, + Required => False, + Subunit => False, + Error_Node => N, + Renamings => True); + + if Unum = No_Unit then + OK := False; + + else + Compiler_State := Analyzing; -- reset after load + + if not Fatal_Error (Unum) or else Try_Semantics then + if Debug_Flag_L then + Write_Str ("*** Loaded generic body"); + Write_Eol; + end if; + + if Do_Analyze then + Semantics (Cunit (Unum)); + end if; + end if; + + OK := True; + end if; + + Style_Check := Save_Style_Check; + end Load_Needed_Body; + + ------------------------- + -- Build_Limited_Views -- + ------------------------- + + procedure Build_Limited_Views (N : Node_Id) is + Unum : constant Unit_Number_Type := + Get_Source_Unit (Library_Unit (N)); + Is_Analyzed : constant Boolean := Analyzed (Cunit (Unum)); + + Shadow_Pack : Entity_Id; + -- The corresponding shadow entity of the withed package. This entity + -- offers incomplete views of packages and types as well as abstract + -- views of states and variables declared within. + + Last_Shadow : Entity_Id := Empty; + -- The last shadow entity created by routine Build_Shadow_Entity + + procedure Build_Shadow_Entity + (Ent : Entity_Id; + Scop : Entity_Id; + Shadow : out Entity_Id; + Is_Tagged : Boolean := False); + -- Create a shadow entity that hides Ent and offers an abstract or + -- incomplete view of Ent. Scop is the proper scope. Flag Is_Tagged + -- should be set when Ent is a tagged type. The generated entity is + -- added to Lim_Header. This routine updates the value of Last_Shadow. + + procedure Decorate_Package (Ent : Entity_Id; Scop : Entity_Id); + -- Perform minimal decoration of a package or its corresponding shadow + -- entity denoted by Ent. Scop is the proper scope. + + procedure Decorate_State (Ent : Entity_Id; Scop : Entity_Id); + -- Perform full decoration of an abstract state or its corresponding + -- shadow entity denoted by Ent. Scop is the proper scope. + + procedure Decorate_Type + (Ent : Entity_Id; + Scop : Entity_Id; + Is_Tagged : Boolean := False; + Materialize : Boolean := False); + -- Perform minimal decoration of a type or its corresponding shadow + -- entity denoted by Ent. Scop is the proper scope. Flag Is_Tagged + -- should be set when Ent is a tagged type. Flag Materialize should be + -- set when Ent is a tagged type and its class-wide type needs to appear + -- in the tree. + + procedure Decorate_Variable (Ent : Entity_Id; Scop : Entity_Id); + -- Perform minimal decoration of a variable denoted by Ent. Scop is the + -- proper scope. + + procedure Process_Declarations_And_States + (Pack : Entity_Id; + Decls : List_Id; + Scop : Entity_Id; + Create_Abstract_Views : Boolean); + -- Inspect the states of package Pack and declarative list Decls. Create + -- shadow entities for all nested packages, states, types and variables + -- encountered. Scop is the proper scope. Create_Abstract_Views should + -- be set when the abstract states and variables need to be processed. + + ------------------------- + -- Build_Shadow_Entity -- + ------------------------- + + procedure Build_Shadow_Entity + (Ent : Entity_Id; + Scop : Entity_Id; + Shadow : out Entity_Id; + Is_Tagged : Boolean := False) + is + begin + Shadow := Make_Temporary (Sloc (Ent), 'Z'); + + -- The shadow entity must share the same name and parent as the + -- entity it hides. + + Set_Chars (Shadow, Chars (Ent)); + Set_Parent (Shadow, Parent (Ent)); + + -- The abstract view of a variable is a state, not another variable + + if Ekind (Ent) = E_Variable then + Set_Ekind (Shadow, E_Abstract_State); + else + Set_Ekind (Shadow, Ekind (Ent)); + end if; + + Set_Is_Internal (Shadow); + Set_From_Limited_With (Shadow); + + -- Add the new shadow entity to the limited view of the package + + Last_Shadow := Shadow; + Append_Entity (Shadow, Shadow_Pack); + + -- Perform context-specific decoration of the shadow entity + + if Ekind (Ent) = E_Abstract_State then + Decorate_State (Shadow, Scop); + Set_Non_Limited_View (Shadow, Ent); + + elsif Ekind (Ent) = E_Package then + Decorate_Package (Shadow, Scop); + + elsif Is_Type (Ent) then + Decorate_Type (Shadow, Scop, Is_Tagged); + Set_Non_Limited_View (Shadow, Ent); + + if Is_Incomplete_Or_Private_Type (Ent) then + Set_Private_Dependents (Shadow, New_Elmt_List); + end if; + + elsif Ekind (Ent) = E_Variable then + Decorate_State (Shadow, Scop); + Set_Non_Limited_View (Shadow, Ent); + end if; + end Build_Shadow_Entity; + + ---------------------- + -- Decorate_Package -- + ---------------------- + + procedure Decorate_Package (Ent : Entity_Id; Scop : Entity_Id) is + begin + Set_Ekind (Ent, E_Package); + Set_Etype (Ent, Standard_Void_Type); + Set_Scope (Ent, Scop); + end Decorate_Package; + + -------------------- + -- Decorate_State -- + -------------------- + + procedure Decorate_State (Ent : Entity_Id; Scop : Entity_Id) is + begin + Set_Ekind (Ent, E_Abstract_State); + Set_Etype (Ent, Standard_Void_Type); + Set_Scope (Ent, Scop); + Set_Encapsulating_State (Ent, Empty); + Set_Refinement_Constituents (Ent, New_Elmt_List); + Set_Part_Of_Constituents (Ent, New_Elmt_List); + end Decorate_State; + + ------------------- + -- Decorate_Type -- + ------------------- + + procedure Decorate_Type + (Ent : Entity_Id; + Scop : Entity_Id; + Is_Tagged : Boolean := False; + Materialize : Boolean := False) + is + CW_Typ : Entity_Id; + + begin + -- An unanalyzed type or a shadow entity of a type is treated as an + -- incomplete type. + + Set_Ekind (Ent, E_Incomplete_Type); + Set_Etype (Ent, Ent); + Set_Scope (Ent, Scop); + Set_Is_First_Subtype (Ent); + Set_Stored_Constraint (Ent, No_Elist); + Set_Full_View (Ent, Empty); + Init_Size_Align (Ent); + + -- A tagged type and its corresponding shadow entity share one common + -- class-wide type. + + if Is_Tagged then + Set_Is_Tagged_Type (Ent); + + if No (Class_Wide_Type (Ent)) then + CW_Typ := + New_External_Entity + (E_Void, Scope (Ent), Sloc (Ent), Ent, 'C', 0, 'T'); + + Set_Class_Wide_Type (Ent, CW_Typ); + + -- Set parent to be the same as the parent of the tagged type. + -- We need a parent field set, and it is supposed to point to + -- the declaration of the type. The tagged type declaration + -- essentially declares two separate types, the tagged type + -- itself and the corresponding class-wide type, so it is + -- reasonable for the parent fields to point to the declaration + -- in both cases. + + Set_Parent (CW_Typ, Parent (Ent)); + + Set_Ekind (CW_Typ, E_Class_Wide_Type); + Set_Etype (CW_Typ, Ent); + Set_Scope (CW_Typ, Scop); + Set_Is_Tagged_Type (CW_Typ); + Set_Is_First_Subtype (CW_Typ); + Init_Size_Align (CW_Typ); + Set_Has_Unknown_Discriminants (CW_Typ); + Set_Class_Wide_Type (CW_Typ, CW_Typ); + Set_Equivalent_Type (CW_Typ, Empty); + Set_From_Limited_With (CW_Typ, From_Limited_With (Ent)); + Set_Materialize_Entity (CW_Typ, Materialize); + end if; + end if; + end Decorate_Type; + + ----------------------- + -- Decorate_Variable -- + ----------------------- + + procedure Decorate_Variable (Ent : Entity_Id; Scop : Entity_Id) is + begin + Set_Ekind (Ent, E_Variable); + Set_Etype (Ent, Standard_Void_Type); + Set_Scope (Ent, Scop); + end Decorate_Variable; + + ------------------------------------- + -- Process_Declarations_And_States -- + ------------------------------------- + + procedure Process_Declarations_And_States + (Pack : Entity_Id; + Decls : List_Id; + Scop : Entity_Id; + Create_Abstract_Views : Boolean) + is + procedure Find_And_Process_States; + -- Determine whether package Pack defines abstract state either by + -- using an aspect or a pragma. If this is the case, build shadow + -- entities for all abstract states of Pack. + + procedure Process_States (States : Elist_Id); + -- Generate shadow entities for all abstract states in list States + + ----------------------------- + -- Find_And_Process_States -- + ----------------------------- + + procedure Find_And_Process_States is + procedure Process_State (State : Node_Id); + -- Generate shadow entities for a single abstract state or + -- multiple states expressed as an aggregate. + + ------------------- + -- Process_State -- + ------------------- + + procedure Process_State (State : Node_Id) is + Loc : constant Source_Ptr := Sloc (State); + Elmt : Node_Id; + Id : Entity_Id; + Name : Name_Id; + + Dummy : Entity_Id; + pragma Unreferenced (Dummy); + + begin + -- Multiple abstract states appear as an aggregate + + if Nkind (State) = N_Aggregate then + Elmt := First (Expressions (State)); + while Present (Elmt) loop + Process_State (Elmt); + + Next (Elmt); + end loop; + return; + + -- A null state has no abstract view + + elsif Nkind (State) = N_Null then + return; + + -- State declaration with various options appears as an + -- extension aggregate. + + elsif Nkind (State) = N_Extension_Aggregate then + Name := Chars (Ancestor_Part (State)); + + -- Simple state declaration + + elsif Nkind (State) = N_Identifier then + Name := Chars (State); + + -- Possibly an illegal state declaration + + else + return; + end if; + + -- Construct a dummy state for the purposes of establishing a + -- non-limited => limited view relation. Note that the dummy + -- state is not added to list Abstract_States to avoid multiple + -- definitions. + + Id := Make_Defining_Identifier (Loc, New_External_Name (Name)); + Set_Parent (Id, State); + Decorate_State (Id, Scop); + + Build_Shadow_Entity (Id, Scop, Dummy); + end Process_State; + + -- Local variables + + Pack_Decl : constant Node_Id := Unit_Declaration_Node (Pack); + Asp : Node_Id; + Decl : Node_Id; + + -- Start of processing for Find_And_Process_States + + begin + -- Find aspect Abstract_State + + Asp := First (Aspect_Specifications (Pack_Decl)); + while Present (Asp) loop + if Chars (Identifier (Asp)) = Name_Abstract_State then + Process_State (Expression (Asp)); + + return; + end if; + + Next (Asp); + end loop; + + -- Find pragma Abstract_State by inspecting the declarations + + Decl := First (Decls); + while Present (Decl) and then Nkind (Decl) = N_Pragma loop + if Pragma_Name (Decl) = Name_Abstract_State then + Process_State + (Get_Pragma_Arg + (First (Pragma_Argument_Associations (Decl)))); + + return; + end if; + + Next (Decl); + end loop; + end Find_And_Process_States; + + -------------------- + -- Process_States -- + -------------------- + + procedure Process_States (States : Elist_Id) is + Dummy : Entity_Id; + Elmt : Elmt_Id; + + begin + Elmt := First_Elmt (States); + while Present (Elmt) loop + Build_Shadow_Entity (Node (Elmt), Scop, Dummy); + + Next_Elmt (Elmt); + end loop; + end Process_States; + + -- Local variables + + Is_Tagged : Boolean; + Decl : Node_Id; + Def : Node_Id; + Def_Id : Entity_Id; + Shadow : Entity_Id; + + -- Start of processing for Process_Declarations_And_States + + begin + -- Build abstract views for all states defined in the package + + if Create_Abstract_Views then + + -- When a package has been analyzed, all states are stored in list + -- Abstract_States. Generate the shadow entities directly. + + if Is_Analyzed then + if Present (Abstract_States (Pack)) then + Process_States (Abstract_States (Pack)); + end if; + + -- The package may declare abstract states by using an aspect or a + -- pragma. Attempt to locate one of these construct and if found, + -- build the shadow entities. + + else + Find_And_Process_States; + end if; + end if; + + -- Inspect the declarative list, looking for nested packages, types + -- and variable declarations. + + Decl := First (Decls); + while Present (Decl) loop + + -- Packages + + if Nkind (Decl) = N_Package_Declaration then + Def_Id := Defining_Entity (Decl); + + -- Perform minor decoration when the withed package has not + -- been analyzed. + + if not Is_Analyzed then + Decorate_Package (Def_Id, Scop); + end if; + + -- Create a shadow entity that offers a limited view of all + -- visible types declared within. + + Build_Shadow_Entity (Def_Id, Scop, Shadow); + + Process_Declarations_And_States + (Pack => Def_Id, + Decls => Visible_Declarations (Specification (Decl)), + Scop => Shadow, + Create_Abstract_Views => Create_Abstract_Views); + + -- Types + + elsif Nkind_In (Decl, N_Full_Type_Declaration, + N_Incomplete_Type_Declaration, + N_Private_Extension_Declaration, + N_Private_Type_Declaration, + N_Protected_Type_Declaration, + N_Task_Type_Declaration) + then + Def_Id := Defining_Entity (Decl); + + -- Determine whether the type is tagged. Note that packages + -- included via a limited with clause are not always analyzed, + -- hence the tree lookup rather than the use of attribute + -- Is_Tagged_Type. + + if Nkind (Decl) = N_Full_Type_Declaration then + Def := Type_Definition (Decl); + + Is_Tagged := + (Nkind (Def) = N_Record_Definition + and then Tagged_Present (Def)) + or else + (Nkind (Def) = N_Derived_Type_Definition + and then Present (Record_Extension_Part (Def))); + + elsif Nkind_In (Decl, N_Incomplete_Type_Declaration, + N_Private_Type_Declaration) + then + Is_Tagged := Tagged_Present (Decl); + + elsif Nkind (Decl) = N_Private_Extension_Declaration then + Is_Tagged := True; + + else + Is_Tagged := False; + end if; + + -- Perform minor decoration when the withed package has not + -- been analyzed. + + if not Is_Analyzed then + Decorate_Type (Def_Id, Scop, Is_Tagged, True); + end if; + + -- Create a shadow entity that hides the type and offers an + -- incomplete view of the said type. + + Build_Shadow_Entity (Def_Id, Scop, Shadow, Is_Tagged); + + -- Variables + + elsif Create_Abstract_Views + and then Nkind (Decl) = N_Object_Declaration + and then not Constant_Present (Decl) + then + Def_Id := Defining_Entity (Decl); + + -- Perform minor decoration when the withed package has not + -- been analyzed. + + if not Is_Analyzed then + Decorate_Variable (Def_Id, Scop); + end if; + + -- Create a shadow entity that hides the variable and offers an + -- abstract view of the said variable. + + Build_Shadow_Entity (Def_Id, Scop, Shadow); + end if; + + Next (Decl); + end loop; + end Process_Declarations_And_States; + + -- Local variables + + Nam : constant Node_Id := Name (N); + Pack : constant Entity_Id := Cunit_Entity (Unum); + + Last_Public_Shadow : Entity_Id := Empty; + Private_Shadow : Entity_Id; + Spec : Node_Id; + + -- Start of processing for Build_Limited_Views + + begin + pragma Assert (Limited_Present (N)); + + -- A library_item mentioned in a limited_with_clause is a package + -- declaration, not a subprogram declaration, generic declaration, + -- generic instantiation, or package renaming declaration. + + case Nkind (Unit (Library_Unit (N))) is + when N_Package_Declaration => + null; + + when N_Subprogram_Declaration => + Error_Msg_N ("subprograms not allowed in limited with_clauses", N); + return; + + when N_Generic_Package_Declaration | + N_Generic_Subprogram_Declaration => + Error_Msg_N ("generics not allowed in limited with_clauses", N); + return; + + when N_Generic_Instantiation => + Error_Msg_N + ("generic instantiations not allowed in limited with_clauses", + N); + return; + + when N_Generic_Renaming_Declaration => + Error_Msg_N + ("generic renamings not allowed in limited with_clauses", N); + return; + + when N_Subprogram_Renaming_Declaration => + Error_Msg_N + ("renamed subprograms not allowed in limited with_clauses", N); + return; + + when N_Package_Renaming_Declaration => + Error_Msg_N + ("renamed packages not allowed in limited with_clauses", N); + return; + + when others => + raise Program_Error; + end case; + + -- The withed unit may not be analyzed, but the with calause itself + -- must be minimally decorated. This ensures that the checks on unused + -- with clauses also process limieted withs. + + Set_Ekind (Pack, E_Package); + Set_Etype (Pack, Standard_Void_Type); + + if Is_Entity_Name (Nam) then + Set_Entity (Nam, Pack); + + elsif Nkind (Nam) = N_Selected_Component then + Set_Entity (Selector_Name (Nam), Pack); + end if; + + -- Check if the chain is already built + + Spec := Specification (Unit (Library_Unit (N))); + + if Limited_View_Installed (Spec) then + return; + end if; + + -- Create the shadow package wich hides the withed unit and provides + -- incomplete view of all types and packages declared within. + + Shadow_Pack := Make_Temporary (Sloc (N), 'Z'); + Set_Ekind (Shadow_Pack, E_Package); + Set_Is_Internal (Shadow_Pack); + Set_Limited_View (Pack, Shadow_Pack); + + -- Inspect the abstract states and visible declarations of the withed + -- unit and create shadow entities that hide existing packages, states, + -- variables and types. + + Process_Declarations_And_States + (Pack => Pack, + Decls => Visible_Declarations (Spec), + Scop => Pack, + Create_Abstract_Views => True); + + Last_Public_Shadow := Last_Shadow; + + -- Ada 2005 (AI-262): Build the limited view of the private declarations + -- to accomodate limited private with clauses. + + Process_Declarations_And_States + (Pack => Pack, + Decls => Private_Declarations (Spec), + Scop => Pack, + Create_Abstract_Views => False); + + if Present (Last_Public_Shadow) then + Private_Shadow := Next_Entity (Last_Public_Shadow); + else + Private_Shadow := First_Entity (Shadow_Pack); + end if; + + Set_First_Private_Entity (Shadow_Pack, Private_Shadow); + Set_Limited_View_Installed (Spec); + end Build_Limited_Views; + + ------------------------------- + -- Check_Body_Needed_For_SAL -- + ------------------------------- + + procedure Check_Body_Needed_For_SAL (Unit_Name : Entity_Id) is + + function Entity_Needs_Body (E : Entity_Id) return Boolean; + -- Determine whether use of entity E might require the presence of its + -- body. For a package this requires a recursive traversal of all nested + -- declarations. + + --------------------------- + -- Entity_Needed_For_SAL -- + --------------------------- + + function Entity_Needs_Body (E : Entity_Id) return Boolean is + Ent : Entity_Id; + + begin + if Is_Subprogram (E) and then Has_Pragma_Inline (E) then + return True; + + elsif Ekind_In (E, E_Generic_Function, E_Generic_Procedure) then + return True; + + elsif Ekind (E) = E_Generic_Package + and then + Nkind (Unit_Declaration_Node (E)) = N_Generic_Package_Declaration + and then Present (Corresponding_Body (Unit_Declaration_Node (E))) + then + return True; + + elsif Ekind (E) = E_Package + and then Nkind (Unit_Declaration_Node (E)) = N_Package_Declaration + and then Present (Corresponding_Body (Unit_Declaration_Node (E))) + then + Ent := First_Entity (E); + while Present (Ent) loop + if Entity_Needs_Body (Ent) then + return True; + end if; + + Next_Entity (Ent); + end loop; + + return False; + + else + return False; + end if; + end Entity_Needs_Body; + + -- Start of processing for Check_Body_Needed_For_SAL + + begin + if Ekind (Unit_Name) = E_Generic_Package + and then Nkind (Unit_Declaration_Node (Unit_Name)) = + N_Generic_Package_Declaration + and then + Present (Corresponding_Body (Unit_Declaration_Node (Unit_Name))) + then + Set_Body_Needed_For_SAL (Unit_Name); + + elsif Ekind_In (Unit_Name, E_Generic_Procedure, E_Generic_Function) then + Set_Body_Needed_For_SAL (Unit_Name); + + elsif Is_Subprogram (Unit_Name) + and then Nkind (Unit_Declaration_Node (Unit_Name)) = + N_Subprogram_Declaration + and then Has_Pragma_Inline (Unit_Name) + then + Set_Body_Needed_For_SAL (Unit_Name); + + elsif Ekind (Unit_Name) = E_Subprogram_Body then + Check_Body_Needed_For_SAL + (Corresponding_Spec (Unit_Declaration_Node (Unit_Name))); + + elsif Ekind (Unit_Name) = E_Package + and then Entity_Needs_Body (Unit_Name) + then + Set_Body_Needed_For_SAL (Unit_Name); + + elsif Ekind (Unit_Name) = E_Package_Body + and then Nkind (Unit_Declaration_Node (Unit_Name)) = N_Package_Body + then + Check_Body_Needed_For_SAL + (Corresponding_Spec (Unit_Declaration_Node (Unit_Name))); + end if; + end Check_Body_Needed_For_SAL; + + -------------------- + -- Remove_Context -- + -------------------- + + procedure Remove_Context (N : Node_Id) is + Lib_Unit : constant Node_Id := Unit (N); + + begin + -- If this is a child unit, first remove the parent units + + if Is_Child_Spec (Lib_Unit) then + Remove_Parents (Lib_Unit); + end if; + + Remove_Context_Clauses (N); + end Remove_Context; + + ---------------------------- + -- Remove_Context_Clauses -- + ---------------------------- + + procedure Remove_Context_Clauses (N : Node_Id) is + Item : Node_Id; + Unit_Name : Entity_Id; + + begin + -- Ada 2005 (AI-50217): We remove the context clauses in two phases: + -- limited-views first and regular-views later (to maintain the + -- stack model). + + -- First Phase: Remove limited_with context clauses + + Item := First (Context_Items (N)); + while Present (Item) loop + + -- We are interested only in with clauses which got installed + -- on entry. + + if Nkind (Item) = N_With_Clause + and then Limited_Present (Item) + and then Limited_View_Installed (Item) + then + Remove_Limited_With_Clause (Item); + end if; + + Next (Item); + end loop; + + -- Second Phase: Loop through context items and undo regular + -- with_clauses and use_clauses. + + Item := First (Context_Items (N)); + while Present (Item) loop + + -- We are interested only in with clauses which got installed on + -- entry, as indicated by their Context_Installed flag set + + if Nkind (Item) = N_With_Clause + and then Limited_Present (Item) + and then Limited_View_Installed (Item) + then + null; + + elsif Nkind (Item) = N_With_Clause + and then Context_Installed (Item) + then + -- Remove items from one with'ed unit + + Unit_Name := Entity (Name (Item)); + Remove_Unit_From_Visibility (Unit_Name); + Set_Context_Installed (Item, False); + + elsif Nkind (Item) = N_Use_Package_Clause then + End_Use_Package (Item); + + elsif Nkind (Item) = N_Use_Type_Clause then + End_Use_Type (Item); + end if; + + Next (Item); + end loop; + end Remove_Context_Clauses; + + -------------------------------- + -- Remove_Limited_With_Clause -- + -------------------------------- + + procedure Remove_Limited_With_Clause (N : Node_Id) is + P_Unit : constant Entity_Id := Unit (Library_Unit (N)); + E : Entity_Id; + P : Entity_Id; + Lim_Header : Entity_Id; + Lim_Typ : Entity_Id; + Prev : Entity_Id; + + begin + pragma Assert (Limited_View_Installed (N)); + + -- In case of limited with_clause on subprograms, generics, instances, + -- or renamings, the corresponding error was previously posted and we + -- have nothing to do here. + + if Nkind (P_Unit) /= N_Package_Declaration then + return; + end if; + + P := Defining_Unit_Name (Specification (P_Unit)); + + -- Handle child packages + + if Nkind (P) = N_Defining_Program_Unit_Name then + P := Defining_Identifier (P); + end if; + + if Debug_Flag_I then + Write_Str ("remove limited view of "); + Write_Name (Chars (P)); + Write_Str (" from visibility"); + Write_Eol; + end if; + + -- Prepare the removal of the shadow entities from visibility. The first + -- element of the limited view is a header (an E_Package entity) that is + -- used to reference the first shadow entity in the private part of the + -- package + + Lim_Header := Limited_View (P); + Lim_Typ := First_Entity (Lim_Header); + + -- Remove package and shadow entities from visibility if it has not + -- been analyzed + + if not Analyzed (P_Unit) then + Unchain (P); + Set_Is_Immediately_Visible (P, False); + + while Present (Lim_Typ) loop + Unchain (Lim_Typ); + Next_Entity (Lim_Typ); + end loop; + + -- Otherwise this package has already appeared in the closure and its + -- shadow entities must be replaced by its real entities. This code + -- must be kept synchronized with the complementary code in Install + -- Limited_Withed_Unit. + + else + -- Real entities that are type or subtype declarations were hidden + -- from visibility at the point of installation of the limited-view. + -- Now we recover the previous value of the hidden attribute. + + E := First_Entity (P); + while Present (E) and then E /= First_Private_Entity (P) loop + if Is_Type (E) then + Set_Is_Hidden (E, Was_Hidden (E)); + end if; + + Next_Entity (E); + end loop; + + while Present (Lim_Typ) + and then Lim_Typ /= First_Private_Entity (Lim_Header) + loop + -- Nested packages and child units were not unchained + + if Ekind (Lim_Typ) /= E_Package + and then not Is_Child_Unit (Non_Limited_View (Lim_Typ)) + then + -- If the package has incomplete types, the limited view of the + -- incomplete type is in fact never visible (AI05-129) but we + -- have created a shadow entity E1 for it, that points to E2, + -- a non-limited incomplete type. This in turn has a full view + -- E3 that is the full declaration. There is a corresponding + -- shadow entity E4. When reinstalling the non-limited view, + -- E2 must become the current entity and E3 must be ignored. + + E := Non_Limited_View (Lim_Typ); + + if Present (Current_Entity (E)) + and then Ekind (Current_Entity (E)) = E_Incomplete_Type + and then Full_View (Current_Entity (E)) = E + then + + -- Lim_Typ is the limited view of a full type declaration + -- that has a previous incomplete declaration, i.e. E3 from + -- the previous description. Nothing to insert. + + null; + + else + pragma Assert (not In_Chain (E)); + + Prev := Current_Entity (Lim_Typ); + + if Prev = Lim_Typ then + Set_Current_Entity (E); + + else + while Present (Prev) + and then Homonym (Prev) /= Lim_Typ + loop + Prev := Homonym (Prev); + end loop; + + if Present (Prev) then + Set_Homonym (Prev, E); + end if; + end if; + + -- Preserve structure of homonym chain + + Set_Homonym (E, Homonym (Lim_Typ)); + end if; + end if; + + Next_Entity (Lim_Typ); + end loop; + end if; + + -- Indicate that the limited view of the package is not installed + + Set_From_Limited_With (P, False); + Set_Limited_View_Installed (N, False); + end Remove_Limited_With_Clause; + + -------------------- + -- Remove_Parents -- + -------------------- + + procedure Remove_Parents (Lib_Unit : Node_Id) is + P : Node_Id; + P_Name : Entity_Id; + P_Spec : Node_Id := Empty; + E : Entity_Id; + Vis : constant Boolean := + Scope_Stack.Table (Scope_Stack.Last).Previous_Visibility; + + begin + if Is_Child_Spec (Lib_Unit) then + P_Spec := Parent_Spec (Lib_Unit); + + elsif Nkind (Lib_Unit) = N_Package_Body + and then Nkind (Original_Node (Lib_Unit)) = N_Package_Instantiation + then + P_Spec := Parent_Spec (Original_Node (Lib_Unit)); + end if; + + if Present (P_Spec) then + P := Unit (P_Spec); + P_Name := Get_Parent_Entity (P); + Remove_Context_Clauses (P_Spec); + End_Package_Scope (P_Name); + Set_Is_Immediately_Visible (P_Name, Vis); + + -- Remove from visibility the siblings as well, which are directly + -- visible while the parent is in scope. + + E := First_Entity (P_Name); + while Present (E) loop + if Is_Child_Unit (E) then + Set_Is_Immediately_Visible (E, False); + end if; + + Next_Entity (E); + end loop; + + Set_In_Package_Body (P_Name, False); + + -- This is the recursive call to remove the context of any higher + -- level parent. This recursion ensures that all parents are removed + -- in the reverse order of their installation. + + Remove_Parents (P); + end if; + end Remove_Parents; + + --------------------------------- + -- Remove_Private_With_Clauses -- + --------------------------------- + + procedure Remove_Private_With_Clauses (Comp_Unit : Node_Id) is + Item : Node_Id; + + function In_Regular_With_Clause (E : Entity_Id) return Boolean; + -- Check whether a given unit appears in a regular with_clause. Used to + -- determine whether a private_with_clause, implicit or explicit, should + -- be ignored. + + ---------------------------- + -- In_Regular_With_Clause -- + ---------------------------- + + function In_Regular_With_Clause (E : Entity_Id) return Boolean + is + Item : Node_Id; + + begin + Item := First (Context_Items (Comp_Unit)); + while Present (Item) loop + if Nkind (Item) = N_With_Clause + and then Entity (Name (Item)) = E + and then not Private_Present (Item) + then + return True; + end if; + Next (Item); + end loop; + + return False; + end In_Regular_With_Clause; + + -- Start of processing for Remove_Private_With_Clauses + + begin + Item := First (Context_Items (Comp_Unit)); + while Present (Item) loop + if Nkind (Item) = N_With_Clause and then Private_Present (Item) then + + -- If private_with_clause is redundant, remove it from context, + -- as a small optimization to subsequent handling of private_with + -- clauses in other nested packages. + + if In_Regular_With_Clause (Entity (Name (Item))) then + declare + Nxt : constant Node_Id := Next (Item); + begin + Remove (Item); + Item := Nxt; + end; + + elsif Limited_Present (Item) then + if not Limited_View_Installed (Item) then + Remove_Limited_With_Clause (Item); + end if; + + Next (Item); + + else + Remove_Unit_From_Visibility (Entity (Name (Item))); + Set_Context_Installed (Item, False); + Next (Item); + end if; + + else + Next (Item); + end if; + end loop; + end Remove_Private_With_Clauses; + + --------------------------------- + -- Remove_Unit_From_Visibility -- + --------------------------------- + + procedure Remove_Unit_From_Visibility (Unit_Name : Entity_Id) is + begin + if Debug_Flag_I then + Write_Str ("remove unit "); + Write_Name (Chars (Unit_Name)); + Write_Str (" from visibility"); + Write_Eol; + end if; + + Set_Is_Visible_Lib_Unit (Unit_Name, False); + Set_Is_Potentially_Use_Visible (Unit_Name, False); + Set_Is_Immediately_Visible (Unit_Name, False); + + -- If the unit is a wrapper package, the subprogram instance is + -- what must be removed from visibility. + -- Should we use Related_Instance instead??? + + if Is_Wrapper_Package (Unit_Name) then + Set_Is_Immediately_Visible (Current_Entity (Unit_Name), False); + end if; + end Remove_Unit_From_Visibility; + + -------- + -- sm -- + -------- + + procedure sm is + begin + null; + end sm; + + ------------- + -- Unchain -- + ------------- + + procedure Unchain (E : Entity_Id) is + Prev : Entity_Id; + + begin + Prev := Current_Entity (E); + + if No (Prev) then + return; + + elsif Prev = E then + Set_Name_Entity_Id (Chars (E), Homonym (E)); + + else + while Present (Prev) and then Homonym (Prev) /= E loop + Prev := Homonym (Prev); + end loop; + + if Present (Prev) then + Set_Homonym (Prev, Homonym (E)); + end if; + end if; + + if Debug_Flag_I then + Write_Str (" (homonym) unchain "); + Write_Name (Chars (E)); + Write_Eol; + end if; + end Unchain; + +end Sem_Ch10; |