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Diffstat (limited to 'gcc-4.2.1/gcc/ada/sem_util.adb')
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1 files changed, 7209 insertions, 0 deletions
diff --git a/gcc-4.2.1/gcc/ada/sem_util.adb b/gcc-4.2.1/gcc/ada/sem_util.adb new file mode 100644 index 000000000..a9b64c701 --- /dev/null +++ b/gcc-4.2.1/gcc/ada/sem_util.adb @@ -0,0 +1,7209 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S E M _ U T I L -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 1992-2006, 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 2, 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 COPYING. If not, write -- +-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, -- +-- Boston, MA 02110-1301, USA. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- -- +------------------------------------------------------------------------------ + +with Atree; use Atree; +with Casing; use Casing; +with Checks; use Checks; +with Debug; use Debug; +with Errout; use Errout; +with Elists; use Elists; +with Exp_Tss; use Exp_Tss; +with Exp_Util; use Exp_Util; +with Fname; use Fname; +with Freeze; use Freeze; +with Lib; use Lib; +with Lib.Xref; use Lib.Xref; +with Namet; use Namet; +with Nlists; use Nlists; +with Nmake; use Nmake; +with Output; use Output; +with Opt; use Opt; +with Restrict; use Restrict; +with Rident; use Rident; +with Rtsfind; use Rtsfind; +with Scans; use Scans; +with Scn; use Scn; +with Sem; use Sem; +with Sem_Ch8; use Sem_Ch8; +with Sem_Eval; use Sem_Eval; +with Sem_Res; use Sem_Res; +with Sem_Type; use Sem_Type; +with Sinfo; use Sinfo; +with Sinput; use Sinput; +with Snames; use Snames; +with Stand; use Stand; +with Style; +with Stringt; use Stringt; +with Targparm; use Targparm; +with Tbuild; use Tbuild; +with Ttypes; use Ttypes; +with Uname; use Uname; + +package body Sem_Util is + + ----------------------- + -- Local Subprograms -- + ----------------------- + + function Build_Component_Subtype + (C : List_Id; + Loc : Source_Ptr; + T : Entity_Id) return Node_Id; + -- This function builds the subtype for Build_Actual_Subtype_Of_Component + -- and Build_Discriminal_Subtype_Of_Component. C is a list of constraints, + -- Loc is the source location, T is the original subtype. + + function Is_Fully_Initialized_Variant (Typ : Entity_Id) return Boolean; + -- Subsidiary to Is_Fully_Initialized_Type. For an unconstrained type + -- with discriminants whose default values are static, examine only the + -- components in the selected variant to determine whether all of them + -- have a default. + + function Has_Null_Extension (T : Entity_Id) return Boolean; + -- T is a derived tagged type. Check whether the type extension is null. + -- If the parent type is fully initialized, T can be treated as such. + + -------------------------------- + -- Add_Access_Type_To_Process -- + -------------------------------- + + procedure Add_Access_Type_To_Process (E : Entity_Id; A : Entity_Id) is + L : Elist_Id; + + begin + Ensure_Freeze_Node (E); + L := Access_Types_To_Process (Freeze_Node (E)); + + if No (L) then + L := New_Elmt_List; + Set_Access_Types_To_Process (Freeze_Node (E), L); + end if; + + Append_Elmt (A, L); + end Add_Access_Type_To_Process; + + ----------------------- + -- Alignment_In_Bits -- + ----------------------- + + function Alignment_In_Bits (E : Entity_Id) return Uint is + begin + return Alignment (E) * System_Storage_Unit; + end Alignment_In_Bits; + + ----------------------------------------- + -- Apply_Compile_Time_Constraint_Error -- + ----------------------------------------- + + procedure Apply_Compile_Time_Constraint_Error + (N : Node_Id; + Msg : String; + Reason : RT_Exception_Code; + Ent : Entity_Id := Empty; + Typ : Entity_Id := Empty; + Loc : Source_Ptr := No_Location; + Rep : Boolean := True; + Warn : Boolean := False) + is + Stat : constant Boolean := Is_Static_Expression (N); + Rtyp : Entity_Id; + + begin + if No (Typ) then + Rtyp := Etype (N); + else + Rtyp := Typ; + end if; + + Discard_Node + (Compile_Time_Constraint_Error (N, Msg, Ent, Loc, Warn => Warn)); + + if not Rep then + return; + end if; + + -- Now we replace the node by an N_Raise_Constraint_Error node + -- This does not need reanalyzing, so set it as analyzed now. + + Rewrite (N, + Make_Raise_Constraint_Error (Sloc (N), + Reason => Reason)); + Set_Analyzed (N, True); + Set_Etype (N, Rtyp); + Set_Raises_Constraint_Error (N); + + -- If the original expression was marked as static, the result is + -- still marked as static, but the Raises_Constraint_Error flag is + -- always set so that further static evaluation is not attempted. + + if Stat then + Set_Is_Static_Expression (N); + end if; + end Apply_Compile_Time_Constraint_Error; + + -------------------------- + -- Build_Actual_Subtype -- + -------------------------- + + function Build_Actual_Subtype + (T : Entity_Id; + N : Node_Or_Entity_Id) return Node_Id + is + Obj : Node_Id; + + Loc : constant Source_Ptr := Sloc (N); + Constraints : List_Id; + Decl : Node_Id; + Discr : Entity_Id; + Hi : Node_Id; + Lo : Node_Id; + Subt : Entity_Id; + Disc_Type : Entity_Id; + + begin + if Nkind (N) = N_Defining_Identifier then + Obj := New_Reference_To (N, Loc); + else + Obj := N; + end if; + + if Is_Array_Type (T) then + Constraints := New_List; + + for J in 1 .. Number_Dimensions (T) loop + + -- Build an array subtype declaration with the nominal + -- subtype and the bounds of the actual. Add the declaration + -- in front of the local declarations for the subprogram, for + -- analysis before any reference to the formal in the body. + + Lo := + Make_Attribute_Reference (Loc, + Prefix => + Duplicate_Subexpr_No_Checks (Obj, Name_Req => True), + Attribute_Name => Name_First, + Expressions => New_List ( + Make_Integer_Literal (Loc, J))); + + Hi := + Make_Attribute_Reference (Loc, + Prefix => + Duplicate_Subexpr_No_Checks (Obj, Name_Req => True), + Attribute_Name => Name_Last, + Expressions => New_List ( + Make_Integer_Literal (Loc, J))); + + Append (Make_Range (Loc, Lo, Hi), Constraints); + end loop; + + -- If the type has unknown discriminants there is no constrained + -- subtype to build. This is never called for a formal or for a + -- lhs, so returning the type is ok ??? + + elsif Has_Unknown_Discriminants (T) then + return T; + + else + Constraints := New_List; + + if Is_Private_Type (T) and then No (Full_View (T)) then + + -- Type is a generic derived type. Inherit discriminants from + -- Parent type. + + Disc_Type := Etype (Base_Type (T)); + else + Disc_Type := T; + end if; + + Discr := First_Discriminant (Disc_Type); + + while Present (Discr) loop + Append_To (Constraints, + Make_Selected_Component (Loc, + Prefix => + Duplicate_Subexpr_No_Checks (Obj), + Selector_Name => New_Occurrence_Of (Discr, Loc))); + Next_Discriminant (Discr); + end loop; + end if; + + Subt := + Make_Defining_Identifier (Loc, + Chars => New_Internal_Name ('S')); + Set_Is_Internal (Subt); + + Decl := + Make_Subtype_Declaration (Loc, + Defining_Identifier => Subt, + Subtype_Indication => + Make_Subtype_Indication (Loc, + Subtype_Mark => New_Reference_To (T, Loc), + Constraint => + Make_Index_Or_Discriminant_Constraint (Loc, + Constraints => Constraints))); + + Mark_Rewrite_Insertion (Decl); + return Decl; + end Build_Actual_Subtype; + + --------------------------------------- + -- Build_Actual_Subtype_Of_Component -- + --------------------------------------- + + function Build_Actual_Subtype_Of_Component + (T : Entity_Id; + N : Node_Id) return Node_Id + is + Loc : constant Source_Ptr := Sloc (N); + P : constant Node_Id := Prefix (N); + D : Elmt_Id; + Id : Node_Id; + Indx_Type : Entity_Id; + + Deaccessed_T : Entity_Id; + -- This is either a copy of T, or if T is an access type, then it is + -- the directly designated type of this access type. + + function Build_Actual_Array_Constraint return List_Id; + -- If one or more of the bounds of the component depends on + -- discriminants, build actual constraint using the discriminants + -- of the prefix. + + function Build_Actual_Record_Constraint return List_Id; + -- Similar to previous one, for discriminated components constrained + -- by the discriminant of the enclosing object. + + ----------------------------------- + -- Build_Actual_Array_Constraint -- + ----------------------------------- + + function Build_Actual_Array_Constraint return List_Id is + Constraints : constant List_Id := New_List; + Indx : Node_Id; + Hi : Node_Id; + Lo : Node_Id; + Old_Hi : Node_Id; + Old_Lo : Node_Id; + + begin + Indx := First_Index (Deaccessed_T); + while Present (Indx) loop + Old_Lo := Type_Low_Bound (Etype (Indx)); + Old_Hi := Type_High_Bound (Etype (Indx)); + + if Denotes_Discriminant (Old_Lo) then + Lo := + Make_Selected_Component (Loc, + Prefix => New_Copy_Tree (P), + Selector_Name => New_Occurrence_Of (Entity (Old_Lo), Loc)); + + else + Lo := New_Copy_Tree (Old_Lo); + + -- The new bound will be reanalyzed in the enclosing + -- declaration. For literal bounds that come from a type + -- declaration, the type of the context must be imposed, so + -- insure that analysis will take place. For non-universal + -- types this is not strictly necessary. + + Set_Analyzed (Lo, False); + end if; + + if Denotes_Discriminant (Old_Hi) then + Hi := + Make_Selected_Component (Loc, + Prefix => New_Copy_Tree (P), + Selector_Name => New_Occurrence_Of (Entity (Old_Hi), Loc)); + + else + Hi := New_Copy_Tree (Old_Hi); + Set_Analyzed (Hi, False); + end if; + + Append (Make_Range (Loc, Lo, Hi), Constraints); + Next_Index (Indx); + end loop; + + return Constraints; + end Build_Actual_Array_Constraint; + + ------------------------------------ + -- Build_Actual_Record_Constraint -- + ------------------------------------ + + function Build_Actual_Record_Constraint return List_Id is + Constraints : constant List_Id := New_List; + D : Elmt_Id; + D_Val : Node_Id; + + begin + D := First_Elmt (Discriminant_Constraint (Deaccessed_T)); + while Present (D) loop + + if Denotes_Discriminant (Node (D)) then + D_Val := Make_Selected_Component (Loc, + Prefix => New_Copy_Tree (P), + Selector_Name => New_Occurrence_Of (Entity (Node (D)), Loc)); + + else + D_Val := New_Copy_Tree (Node (D)); + end if; + + Append (D_Val, Constraints); + Next_Elmt (D); + end loop; + + return Constraints; + end Build_Actual_Record_Constraint; + + -- Start of processing for Build_Actual_Subtype_Of_Component + + begin + if In_Default_Expression then + return Empty; + + elsif Nkind (N) = N_Explicit_Dereference then + if Is_Composite_Type (T) + and then not Is_Constrained (T) + and then not (Is_Class_Wide_Type (T) + and then Is_Constrained (Root_Type (T))) + and then not Has_Unknown_Discriminants (T) + then + -- If the type of the dereference is already constrained, it + -- is an actual subtype. + + if Is_Array_Type (Etype (N)) + and then Is_Constrained (Etype (N)) + then + return Empty; + else + Remove_Side_Effects (P); + return Build_Actual_Subtype (T, N); + end if; + else + return Empty; + end if; + end if; + + if Ekind (T) = E_Access_Subtype then + Deaccessed_T := Designated_Type (T); + else + Deaccessed_T := T; + end if; + + if Ekind (Deaccessed_T) = E_Array_Subtype then + Id := First_Index (Deaccessed_T); + + while Present (Id) loop + Indx_Type := Underlying_Type (Etype (Id)); + + if Denotes_Discriminant (Type_Low_Bound (Indx_Type)) or else + Denotes_Discriminant (Type_High_Bound (Indx_Type)) + then + Remove_Side_Effects (P); + return + Build_Component_Subtype ( + Build_Actual_Array_Constraint, Loc, Base_Type (T)); + end if; + + Next_Index (Id); + end loop; + + elsif Is_Composite_Type (Deaccessed_T) + and then Has_Discriminants (Deaccessed_T) + and then not Has_Unknown_Discriminants (Deaccessed_T) + then + D := First_Elmt (Discriminant_Constraint (Deaccessed_T)); + while Present (D) loop + + if Denotes_Discriminant (Node (D)) then + Remove_Side_Effects (P); + return + Build_Component_Subtype ( + Build_Actual_Record_Constraint, Loc, Base_Type (T)); + end if; + + Next_Elmt (D); + end loop; + end if; + + -- If none of the above, the actual and nominal subtypes are the same + + return Empty; + end Build_Actual_Subtype_Of_Component; + + ----------------------------- + -- Build_Component_Subtype -- + ----------------------------- + + function Build_Component_Subtype + (C : List_Id; + Loc : Source_Ptr; + T : Entity_Id) return Node_Id + is + Subt : Entity_Id; + Decl : Node_Id; + + begin + -- Unchecked_Union components do not require component subtypes + + if Is_Unchecked_Union (T) then + return Empty; + end if; + + Subt := + Make_Defining_Identifier (Loc, + Chars => New_Internal_Name ('S')); + Set_Is_Internal (Subt); + + Decl := + Make_Subtype_Declaration (Loc, + Defining_Identifier => Subt, + Subtype_Indication => + Make_Subtype_Indication (Loc, + Subtype_Mark => New_Reference_To (Base_Type (T), Loc), + Constraint => + Make_Index_Or_Discriminant_Constraint (Loc, + Constraints => C))); + + Mark_Rewrite_Insertion (Decl); + return Decl; + end Build_Component_Subtype; + + -------------------------------------------- + -- Build_Discriminal_Subtype_Of_Component -- + -------------------------------------------- + + function Build_Discriminal_Subtype_Of_Component + (T : Entity_Id) return Node_Id + is + Loc : constant Source_Ptr := Sloc (T); + D : Elmt_Id; + Id : Node_Id; + + function Build_Discriminal_Array_Constraint return List_Id; + -- If one or more of the bounds of the component depends on + -- discriminants, build actual constraint using the discriminants + -- of the prefix. + + function Build_Discriminal_Record_Constraint return List_Id; + -- Similar to previous one, for discriminated components constrained + -- by the discriminant of the enclosing object. + + ---------------------------------------- + -- Build_Discriminal_Array_Constraint -- + ---------------------------------------- + + function Build_Discriminal_Array_Constraint return List_Id is + Constraints : constant List_Id := New_List; + Indx : Node_Id; + Hi : Node_Id; + Lo : Node_Id; + Old_Hi : Node_Id; + Old_Lo : Node_Id; + + begin + Indx := First_Index (T); + while Present (Indx) loop + Old_Lo := Type_Low_Bound (Etype (Indx)); + Old_Hi := Type_High_Bound (Etype (Indx)); + + if Denotes_Discriminant (Old_Lo) then + Lo := New_Occurrence_Of (Discriminal (Entity (Old_Lo)), Loc); + + else + Lo := New_Copy_Tree (Old_Lo); + end if; + + if Denotes_Discriminant (Old_Hi) then + Hi := New_Occurrence_Of (Discriminal (Entity (Old_Hi)), Loc); + + else + Hi := New_Copy_Tree (Old_Hi); + end if; + + Append (Make_Range (Loc, Lo, Hi), Constraints); + Next_Index (Indx); + end loop; + + return Constraints; + end Build_Discriminal_Array_Constraint; + + ----------------------------------------- + -- Build_Discriminal_Record_Constraint -- + ----------------------------------------- + + function Build_Discriminal_Record_Constraint return List_Id is + Constraints : constant List_Id := New_List; + D : Elmt_Id; + D_Val : Node_Id; + + begin + D := First_Elmt (Discriminant_Constraint (T)); + while Present (D) loop + if Denotes_Discriminant (Node (D)) then + D_Val := + New_Occurrence_Of (Discriminal (Entity (Node (D))), Loc); + + else + D_Val := New_Copy_Tree (Node (D)); + end if; + + Append (D_Val, Constraints); + Next_Elmt (D); + end loop; + + return Constraints; + end Build_Discriminal_Record_Constraint; + + -- Start of processing for Build_Discriminal_Subtype_Of_Component + + begin + if Ekind (T) = E_Array_Subtype then + Id := First_Index (T); + + while Present (Id) loop + if Denotes_Discriminant (Type_Low_Bound (Etype (Id))) or else + Denotes_Discriminant (Type_High_Bound (Etype (Id))) + then + return Build_Component_Subtype + (Build_Discriminal_Array_Constraint, Loc, T); + end if; + + Next_Index (Id); + end loop; + + elsif Ekind (T) = E_Record_Subtype + and then Has_Discriminants (T) + and then not Has_Unknown_Discriminants (T) + then + D := First_Elmt (Discriminant_Constraint (T)); + while Present (D) loop + if Denotes_Discriminant (Node (D)) then + return Build_Component_Subtype + (Build_Discriminal_Record_Constraint, Loc, T); + end if; + + Next_Elmt (D); + end loop; + end if; + + -- If none of the above, the actual and nominal subtypes are the same + + return Empty; + end Build_Discriminal_Subtype_Of_Component; + + ------------------------------ + -- Build_Elaboration_Entity -- + ------------------------------ + + procedure Build_Elaboration_Entity (N : Node_Id; Spec_Id : Entity_Id) is + Loc : constant Source_Ptr := Sloc (N); + Unum : constant Unit_Number_Type := Get_Source_Unit (Loc); + Decl : Node_Id; + P : Natural; + Elab_Ent : Entity_Id; + + begin + -- Ignore if already constructed + + if Present (Elaboration_Entity (Spec_Id)) then + return; + end if; + + -- Construct name of elaboration entity as xxx_E, where xxx + -- is the unit name with dots replaced by double underscore. + -- We have to manually construct this name, since it will + -- be elaborated in the outer scope, and thus will not have + -- the unit name automatically prepended. + + Get_Name_String (Unit_Name (Unum)); + + -- Replace the %s by _E + + Name_Buffer (Name_Len - 1 .. Name_Len) := "_E"; + + -- Replace dots by double underscore + + P := 2; + while P < Name_Len - 2 loop + if Name_Buffer (P) = '.' then + Name_Buffer (P + 2 .. Name_Len + 1) := + Name_Buffer (P + 1 .. Name_Len); + Name_Len := Name_Len + 1; + Name_Buffer (P) := '_'; + Name_Buffer (P + 1) := '_'; + P := P + 3; + else + P := P + 1; + end if; + end loop; + + -- Create elaboration flag + + Elab_Ent := + Make_Defining_Identifier (Loc, Chars => Name_Find); + Set_Elaboration_Entity (Spec_Id, Elab_Ent); + + if No (Declarations (Aux_Decls_Node (N))) then + Set_Declarations (Aux_Decls_Node (N), New_List); + end if; + + Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => Elab_Ent, + Object_Definition => + New_Occurrence_Of (Standard_Boolean, Loc), + Expression => + New_Occurrence_Of (Standard_False, Loc)); + + Append_To (Declarations (Aux_Decls_Node (N)), Decl); + Analyze (Decl); + + -- Reset True_Constant indication, since we will indeed + -- assign a value to the variable in the binder main. + + Set_Is_True_Constant (Elab_Ent, False); + Set_Current_Value (Elab_Ent, Empty); + + -- We do not want any further qualification of the name (if we did + -- not do this, we would pick up the name of the generic package + -- in the case of a library level generic instantiation). + + Set_Has_Qualified_Name (Elab_Ent); + Set_Has_Fully_Qualified_Name (Elab_Ent); + end Build_Elaboration_Entity; + + ----------------------------------- + -- Cannot_Raise_Constraint_Error -- + ----------------------------------- + + function Cannot_Raise_Constraint_Error (Expr : Node_Id) return Boolean is + begin + if Compile_Time_Known_Value (Expr) then + return True; + + elsif Do_Range_Check (Expr) then + return False; + + elsif Raises_Constraint_Error (Expr) then + return False; + + else + case Nkind (Expr) is + when N_Identifier => + return True; + + when N_Expanded_Name => + return True; + + when N_Selected_Component => + return not Do_Discriminant_Check (Expr); + + when N_Attribute_Reference => + if Do_Overflow_Check (Expr) then + return False; + + elsif No (Expressions (Expr)) then + return True; + + else + declare + N : Node_Id := First (Expressions (Expr)); + + begin + while Present (N) loop + if Cannot_Raise_Constraint_Error (N) then + Next (N); + else + return False; + end if; + end loop; + + return True; + end; + end if; + + when N_Type_Conversion => + if Do_Overflow_Check (Expr) + or else Do_Length_Check (Expr) + or else Do_Tag_Check (Expr) + then + return False; + else + return + Cannot_Raise_Constraint_Error (Expression (Expr)); + end if; + + when N_Unchecked_Type_Conversion => + return Cannot_Raise_Constraint_Error (Expression (Expr)); + + when N_Unary_Op => + if Do_Overflow_Check (Expr) then + return False; + else + return + Cannot_Raise_Constraint_Error (Right_Opnd (Expr)); + end if; + + when N_Op_Divide | + N_Op_Mod | + N_Op_Rem + => + if Do_Division_Check (Expr) + or else Do_Overflow_Check (Expr) + then + return False; + else + return + Cannot_Raise_Constraint_Error (Left_Opnd (Expr)) + and then + Cannot_Raise_Constraint_Error (Right_Opnd (Expr)); + end if; + + when N_Op_Add | + N_Op_And | + N_Op_Concat | + N_Op_Eq | + N_Op_Expon | + N_Op_Ge | + N_Op_Gt | + N_Op_Le | + N_Op_Lt | + N_Op_Multiply | + N_Op_Ne | + N_Op_Or | + N_Op_Rotate_Left | + N_Op_Rotate_Right | + N_Op_Shift_Left | + N_Op_Shift_Right | + N_Op_Shift_Right_Arithmetic | + N_Op_Subtract | + N_Op_Xor + => + if Do_Overflow_Check (Expr) then + return False; + else + return + Cannot_Raise_Constraint_Error (Left_Opnd (Expr)) + and then + Cannot_Raise_Constraint_Error (Right_Opnd (Expr)); + end if; + + when others => + return False; + end case; + end if; + end Cannot_Raise_Constraint_Error; + + -------------------------- + -- Check_Fully_Declared -- + -------------------------- + + procedure Check_Fully_Declared (T : Entity_Id; N : Node_Id) is + begin + if Ekind (T) = E_Incomplete_Type then + + -- Ada 2005 (AI-50217): If the type is available through a limited + -- with_clause, verify that its full view has been analyzed. + + if From_With_Type (T) + and then Present (Non_Limited_View (T)) + and then Ekind (Non_Limited_View (T)) /= E_Incomplete_Type + then + -- The non-limited view is fully declared + null; + + else + Error_Msg_NE + ("premature usage of incomplete}", N, First_Subtype (T)); + end if; + + elsif Has_Private_Component (T) + and then not Is_Generic_Type (Root_Type (T)) + and then not In_Default_Expression + then + + -- Special case: if T is the anonymous type created for a single + -- task or protected object, use the name of the source object. + + if Is_Concurrent_Type (T) + and then not Comes_From_Source (T) + and then Nkind (N) = N_Object_Declaration + then + Error_Msg_NE ("type of& has incomplete component", N, + Defining_Identifier (N)); + + else + Error_Msg_NE + ("premature usage of incomplete}", N, First_Subtype (T)); + end if; + end if; + end Check_Fully_Declared; + + ----------------------- + -- Check_Obsolescent -- + ----------------------- + + procedure Check_Obsolescent (Nam : Entity_Id; N : Node_Id) is + W : Node_Id; + + begin + -- Note that we always allow obsolescent references in the compiler + -- itself and the run time, since we assume that we know what we are + -- doing in such cases. For example the calls in Ada.Characters.Handling + -- to its own obsolescent subprograms are just fine. + + if Is_Obsolescent (Nam) and then not GNAT_Mode then + Check_Restriction (No_Obsolescent_Features, N); + + if Warn_On_Obsolescent_Feature then + if Is_Package_Or_Generic_Package (Nam) then + Error_Msg_NE ("with of obsolescent package&?", N, Nam); + else + Error_Msg_NE ("call to obsolescent subprogram&?", N, Nam); + end if; + + -- Output additional warning if present + + W := Obsolescent_Warning (Nam); + + if Present (W) then + Name_Buffer (1) := '|'; + Name_Buffer (2) := '?'; + Name_Len := 2; + + -- Add characters to message, and output message + + for J in 1 .. String_Length (Strval (W)) loop + Add_Char_To_Name_Buffer ('''); + Add_Char_To_Name_Buffer + (Get_Character (Get_String_Char (Strval (W), J))); + end loop; + + Error_Msg_N (Name_Buffer (1 .. Name_Len), N); + end if; + end if; + end if; + end Check_Obsolescent; + + ------------------------------------------ + -- Check_Potentially_Blocking_Operation -- + ------------------------------------------ + + procedure Check_Potentially_Blocking_Operation (N : Node_Id) is + S : Entity_Id; + + begin + -- N is one of the potentially blocking operations listed in 9.5.1(8). + -- When pragma Detect_Blocking is active, the run time will raise + -- Program_Error. Here we only issue a warning, since we generally + -- support the use of potentially blocking operations in the absence + -- of the pragma. + + -- Indirect blocking through a subprogram call cannot be diagnosed + -- statically without interprocedural analysis, so we do not attempt + -- to do it here. + + S := Scope (Current_Scope); + while Present (S) and then S /= Standard_Standard loop + if Is_Protected_Type (S) then + Error_Msg_N + ("potentially blocking operation in protected operation?", N); + + return; + end if; + + S := Scope (S); + end loop; + end Check_Potentially_Blocking_Operation; + + --------------- + -- Check_VMS -- + --------------- + + procedure Check_VMS (Construct : Node_Id) is + begin + if not OpenVMS_On_Target then + Error_Msg_N + ("this construct is allowed only in Open'V'M'S", Construct); + end if; + end Check_VMS; + + ---------------------------------- + -- Collect_Primitive_Operations -- + ---------------------------------- + + function Collect_Primitive_Operations (T : Entity_Id) return Elist_Id is + B_Type : constant Entity_Id := Base_Type (T); + B_Decl : constant Node_Id := Original_Node (Parent (B_Type)); + B_Scope : Entity_Id := Scope (B_Type); + Op_List : Elist_Id; + Formal : Entity_Id; + Is_Prim : Boolean; + Formal_Derived : Boolean := False; + Id : Entity_Id; + + begin + -- For tagged types, the primitive operations are collected as they + -- are declared, and held in an explicit list which is simply returned. + + if Is_Tagged_Type (B_Type) then + return Primitive_Operations (B_Type); + + -- An untagged generic type that is a derived type inherits the + -- primitive operations of its parent type. Other formal types only + -- have predefined operators, which are not explicitly represented. + + elsif Is_Generic_Type (B_Type) then + if Nkind (B_Decl) = N_Formal_Type_Declaration + and then Nkind (Formal_Type_Definition (B_Decl)) + = N_Formal_Derived_Type_Definition + then + Formal_Derived := True; + else + return New_Elmt_List; + end if; + end if; + + Op_List := New_Elmt_List; + + if B_Scope = Standard_Standard then + if B_Type = Standard_String then + Append_Elmt (Standard_Op_Concat, Op_List); + + elsif B_Type = Standard_Wide_String then + Append_Elmt (Standard_Op_Concatw, Op_List); + + else + null; + end if; + + elsif (Is_Package_Or_Generic_Package (B_Scope) + and then + Nkind (Parent (Declaration_Node (First_Subtype (T)))) /= + N_Package_Body) + or else Is_Derived_Type (B_Type) + then + -- The primitive operations appear after the base type, except + -- if the derivation happens within the private part of B_Scope + -- and the type is a private type, in which case both the type + -- and some primitive operations may appear before the base + -- type, and the list of candidates starts after the type. + + if In_Open_Scopes (B_Scope) + and then Scope (T) = B_Scope + and then In_Private_Part (B_Scope) + then + Id := Next_Entity (T); + else + Id := Next_Entity (B_Type); + end if; + + while Present (Id) loop + + -- Note that generic formal subprograms are not + -- considered to be primitive operations and thus + -- are never inherited. + + if Is_Overloadable (Id) + and then Nkind (Parent (Parent (Id))) + not in N_Formal_Subprogram_Declaration + then + Is_Prim := False; + + if Base_Type (Etype (Id)) = B_Type then + Is_Prim := True; + else + Formal := First_Formal (Id); + while Present (Formal) loop + if Base_Type (Etype (Formal)) = B_Type then + Is_Prim := True; + exit; + + elsif Ekind (Etype (Formal)) = E_Anonymous_Access_Type + and then Base_Type + (Designated_Type (Etype (Formal))) = B_Type + then + Is_Prim := True; + exit; + end if; + + Next_Formal (Formal); + end loop; + end if; + + -- For a formal derived type, the only primitives are the + -- ones inherited from the parent type. Operations appearing + -- in the package declaration are not primitive for it. + + if Is_Prim + and then (not Formal_Derived + or else Present (Alias (Id))) + then + Append_Elmt (Id, Op_List); + end if; + end if; + + Next_Entity (Id); + + -- For a type declared in System, some of its operations + -- may appear in the target-specific extension to System. + + if No (Id) + and then Chars (B_Scope) = Name_System + and then Scope (B_Scope) = Standard_Standard + and then Present_System_Aux + then + B_Scope := System_Aux_Id; + Id := First_Entity (System_Aux_Id); + end if; + end loop; + end if; + + return Op_List; + end Collect_Primitive_Operations; + + ----------------------------------- + -- Compile_Time_Constraint_Error -- + ----------------------------------- + + function Compile_Time_Constraint_Error + (N : Node_Id; + Msg : String; + Ent : Entity_Id := Empty; + Loc : Source_Ptr := No_Location; + Warn : Boolean := False) return Node_Id + is + Msgc : String (1 .. Msg'Length + 2); + Msgl : Natural; + Wmsg : Boolean; + P : Node_Id; + OldP : Node_Id; + Msgs : Boolean; + Eloc : Source_Ptr; + + begin + -- A static constraint error in an instance body is not a fatal error. + -- we choose to inhibit the message altogether, because there is no + -- obvious node (for now) on which to post it. On the other hand the + -- offending node must be replaced with a constraint_error in any case. + + -- No messages are generated if we already posted an error on this node + + if not Error_Posted (N) then + if Loc /= No_Location then + Eloc := Loc; + else + Eloc := Sloc (N); + end if; + + -- Make all such messages unconditional + + Msgc (1 .. Msg'Length) := Msg; + Msgc (Msg'Length + 1) := '!'; + Msgl := Msg'Length + 1; + + -- Message is a warning, even in Ada 95 case + + if Msg (Msg'Length) = '?' then + Wmsg := True; + + -- In Ada 83, all messages are warnings. In the private part and + -- the body of an instance, constraint_checks are only warnings. + -- We also make this a warning if the Warn parameter is set. + + elsif Warn + or else (Ada_Version = Ada_83 and then Comes_From_Source (N)) + then + Msgl := Msgl + 1; + Msgc (Msgl) := '?'; + Wmsg := True; + + elsif In_Instance_Not_Visible then + Msgl := Msgl + 1; + Msgc (Msgl) := '?'; + Wmsg := True; + + -- Otherwise we have a real error message (Ada 95 static case) + + else + Wmsg := False; + end if; + + -- Should we generate a warning? The answer is not quite yes. The + -- very annoying exception occurs in the case of a short circuit + -- operator where the left operand is static and decisive. Climb + -- parents to see if that is the case we have here. Conditional + -- expressions with decisive conditions are a similar situation. + + Msgs := True; + P := N; + loop + OldP := P; + P := Parent (P); + + -- And then with False as left operand + + if Nkind (P) = N_And_Then + and then Compile_Time_Known_Value (Left_Opnd (P)) + and then Is_False (Expr_Value (Left_Opnd (P))) + then + Msgs := False; + exit; + + -- OR ELSE with True as left operand + + elsif Nkind (P) = N_Or_Else + and then Compile_Time_Known_Value (Left_Opnd (P)) + and then Is_True (Expr_Value (Left_Opnd (P))) + then + Msgs := False; + exit; + + -- Conditional expression + + elsif Nkind (P) = N_Conditional_Expression then + declare + Cond : constant Node_Id := First (Expressions (P)); + Texp : constant Node_Id := Next (Cond); + Fexp : constant Node_Id := Next (Texp); + + begin + if Compile_Time_Known_Value (Cond) then + + -- Condition is True and we are in the right operand + + if Is_True (Expr_Value (Cond)) + and then OldP = Fexp + then + Msgs := False; + exit; + + -- Condition is False and we are in the left operand + + elsif Is_False (Expr_Value (Cond)) + and then OldP = Texp + then + Msgs := False; + exit; + end if; + end if; + end; + + -- Special case for component association in aggregates, where + -- we want to keep climbing up to the parent aggregate. + + elsif Nkind (P) = N_Component_Association + and then Nkind (Parent (P)) = N_Aggregate + then + null; + + -- Keep going if within subexpression + + else + exit when Nkind (P) not in N_Subexpr; + end if; + end loop; + + if Msgs then + if Present (Ent) then + Error_Msg_NEL (Msgc (1 .. Msgl), N, Ent, Eloc); + else + Error_Msg_NEL (Msgc (1 .. Msgl), N, Etype (N), Eloc); + end if; + + if Wmsg then + if Inside_Init_Proc then + Error_Msg_NEL + ("\?& will be raised for objects of this type", + N, Standard_Constraint_Error, Eloc); + else + Error_Msg_NEL + ("\?& will be raised at run time", + N, Standard_Constraint_Error, Eloc); + end if; + else + Error_Msg_NEL + ("\static expression raises&!", + N, Standard_Constraint_Error, Eloc); + end if; + end if; + end if; + + return N; + end Compile_Time_Constraint_Error; + + ----------------------- + -- Conditional_Delay -- + ----------------------- + + procedure Conditional_Delay (New_Ent, Old_Ent : Entity_Id) is + begin + if Has_Delayed_Freeze (Old_Ent) and then not Is_Frozen (Old_Ent) then + Set_Has_Delayed_Freeze (New_Ent); + end if; + end Conditional_Delay; + + -------------------- + -- Current_Entity -- + -------------------- + + -- The currently visible definition for a given identifier is the + -- one most chained at the start of the visibility chain, i.e. the + -- one that is referenced by the Node_Id value of the name of the + -- given identifier. + + function Current_Entity (N : Node_Id) return Entity_Id is + begin + return Get_Name_Entity_Id (Chars (N)); + end Current_Entity; + + ----------------------------- + -- Current_Entity_In_Scope -- + ----------------------------- + + function Current_Entity_In_Scope (N : Node_Id) return Entity_Id is + E : Entity_Id; + CS : constant Entity_Id := Current_Scope; + + Transient_Case : constant Boolean := Scope_Is_Transient; + + begin + E := Get_Name_Entity_Id (Chars (N)); + + while Present (E) + and then Scope (E) /= CS + and then (not Transient_Case or else Scope (E) /= Scope (CS)) + loop + E := Homonym (E); + end loop; + + return E; + end Current_Entity_In_Scope; + + ------------------- + -- Current_Scope -- + ------------------- + + function Current_Scope return Entity_Id is + begin + if Scope_Stack.Last = -1 then + return Standard_Standard; + else + declare + C : constant Entity_Id := + Scope_Stack.Table (Scope_Stack.Last).Entity; + begin + if Present (C) then + return C; + else + return Standard_Standard; + end if; + end; + end if; + end Current_Scope; + + ------------------------ + -- Current_Subprogram -- + ------------------------ + + function Current_Subprogram return Entity_Id is + Scop : constant Entity_Id := Current_Scope; + + begin + if Is_Subprogram (Scop) or else Is_Generic_Subprogram (Scop) then + return Scop; + else + return Enclosing_Subprogram (Scop); + end if; + end Current_Subprogram; + + --------------------- + -- Defining_Entity -- + --------------------- + + function Defining_Entity (N : Node_Id) return Entity_Id is + K : constant Node_Kind := Nkind (N); + Err : Entity_Id := Empty; + + begin + case K is + when + N_Subprogram_Declaration | + N_Abstract_Subprogram_Declaration | + N_Subprogram_Body | + N_Package_Declaration | + N_Subprogram_Renaming_Declaration | + N_Subprogram_Body_Stub | + N_Generic_Subprogram_Declaration | + N_Generic_Package_Declaration | + N_Formal_Subprogram_Declaration + => + return Defining_Entity (Specification (N)); + + when + N_Component_Declaration | + N_Defining_Program_Unit_Name | + N_Discriminant_Specification | + N_Entry_Body | + N_Entry_Declaration | + N_Entry_Index_Specification | + N_Exception_Declaration | + N_Exception_Renaming_Declaration | + N_Formal_Object_Declaration | + N_Formal_Package_Declaration | + N_Formal_Type_Declaration | + N_Full_Type_Declaration | + N_Implicit_Label_Declaration | + N_Incomplete_Type_Declaration | + N_Loop_Parameter_Specification | + N_Number_Declaration | + N_Object_Declaration | + N_Object_Renaming_Declaration | + N_Package_Body_Stub | + N_Parameter_Specification | + N_Private_Extension_Declaration | + N_Private_Type_Declaration | + N_Protected_Body | + N_Protected_Body_Stub | + N_Protected_Type_Declaration | + N_Single_Protected_Declaration | + N_Single_Task_Declaration | + N_Subtype_Declaration | + N_Task_Body | + N_Task_Body_Stub | + N_Task_Type_Declaration + => + return Defining_Identifier (N); + + when N_Subunit => + return Defining_Entity (Proper_Body (N)); + + when + N_Function_Instantiation | + N_Function_Specification | + N_Generic_Function_Renaming_Declaration | + N_Generic_Package_Renaming_Declaration | + N_Generic_Procedure_Renaming_Declaration | + N_Package_Body | + N_Package_Instantiation | + N_Package_Renaming_Declaration | + N_Package_Specification | + N_Procedure_Instantiation | + N_Procedure_Specification + => + declare + Nam : constant Node_Id := Defining_Unit_Name (N); + + begin + if Nkind (Nam) in N_Entity then + return Nam; + + -- For Error, make up a name and attach to declaration + -- so we can continue semantic analysis + + elsif Nam = Error then + Err := + Make_Defining_Identifier (Sloc (N), + Chars => New_Internal_Name ('T')); + Set_Defining_Unit_Name (N, Err); + + return Err; + -- If not an entity, get defining identifier + + else + return Defining_Identifier (Nam); + end if; + end; + + when N_Block_Statement => + return Entity (Identifier (N)); + + when others => + raise Program_Error; + + end case; + end Defining_Entity; + + -------------------------- + -- Denotes_Discriminant -- + -------------------------- + + function Denotes_Discriminant + (N : Node_Id; + Check_Protected : Boolean := False) return Boolean + is + E : Entity_Id; + begin + if not Is_Entity_Name (N) + or else No (Entity (N)) + then + return False; + else + E := Entity (N); + end if; + + -- If we are checking for a protected type, the discriminant may have + -- been rewritten as the corresponding discriminal of the original type + -- or of the corresponding concurrent record, depending on whether we + -- are in the spec or body of the protected type. + + return Ekind (E) = E_Discriminant + or else + (Check_Protected + and then Ekind (E) = E_In_Parameter + and then Present (Discriminal_Link (E)) + and then + (Is_Protected_Type (Scope (Discriminal_Link (E))) + or else + Is_Concurrent_Record_Type (Scope (Discriminal_Link (E))))); + + end Denotes_Discriminant; + + ----------------------------- + -- Depends_On_Discriminant -- + ----------------------------- + + function Depends_On_Discriminant (N : Node_Id) return Boolean is + L : Node_Id; + H : Node_Id; + + begin + Get_Index_Bounds (N, L, H); + return Denotes_Discriminant (L) or else Denotes_Discriminant (H); + end Depends_On_Discriminant; + + ------------------------- + -- Designate_Same_Unit -- + ------------------------- + + function Designate_Same_Unit + (Name1 : Node_Id; + Name2 : Node_Id) return Boolean + is + K1 : constant Node_Kind := Nkind (Name1); + K2 : constant Node_Kind := Nkind (Name2); + + function Prefix_Node (N : Node_Id) return Node_Id; + -- Returns the parent unit name node of a defining program unit name + -- or the prefix if N is a selected component or an expanded name. + + function Select_Node (N : Node_Id) return Node_Id; + -- Returns the defining identifier node of a defining program unit + -- name or the selector node if N is a selected component or an + -- expanded name. + + ----------------- + -- Prefix_Node -- + ----------------- + + function Prefix_Node (N : Node_Id) return Node_Id is + begin + if Nkind (N) = N_Defining_Program_Unit_Name then + return Name (N); + + else + return Prefix (N); + end if; + end Prefix_Node; + + ----------------- + -- Select_Node -- + ----------------- + + function Select_Node (N : Node_Id) return Node_Id is + begin + if Nkind (N) = N_Defining_Program_Unit_Name then + return Defining_Identifier (N); + + else + return Selector_Name (N); + end if; + end Select_Node; + + -- Start of processing for Designate_Next_Unit + + begin + if (K1 = N_Identifier or else + K1 = N_Defining_Identifier) + and then + (K2 = N_Identifier or else + K2 = N_Defining_Identifier) + then + return Chars (Name1) = Chars (Name2); + + elsif + (K1 = N_Expanded_Name or else + K1 = N_Selected_Component or else + K1 = N_Defining_Program_Unit_Name) + and then + (K2 = N_Expanded_Name or else + K2 = N_Selected_Component or else + K2 = N_Defining_Program_Unit_Name) + then + return + (Chars (Select_Node (Name1)) = Chars (Select_Node (Name2))) + and then + Designate_Same_Unit (Prefix_Node (Name1), Prefix_Node (Name2)); + + else + return False; + end if; + end Designate_Same_Unit; + + ---------------------------- + -- Enclosing_Generic_Body -- + ---------------------------- + + function Enclosing_Generic_Body + (N : Node_Id) return Node_Id + is + P : Node_Id; + Decl : Node_Id; + Spec : Node_Id; + + begin + P := Parent (N); + while Present (P) loop + if Nkind (P) = N_Package_Body + or else Nkind (P) = N_Subprogram_Body + then + Spec := Corresponding_Spec (P); + + if Present (Spec) then + Decl := Unit_Declaration_Node (Spec); + + if Nkind (Decl) = N_Generic_Package_Declaration + or else Nkind (Decl) = N_Generic_Subprogram_Declaration + then + return P; + end if; + end if; + end if; + + P := Parent (P); + end loop; + + return Empty; + end Enclosing_Generic_Body; + + ---------------------------- + -- Enclosing_Generic_Unit -- + ---------------------------- + + function Enclosing_Generic_Unit + (N : Node_Id) return Node_Id + is + P : Node_Id; + Decl : Node_Id; + Spec : Node_Id; + + begin + P := Parent (N); + while Present (P) loop + if Nkind (P) = N_Generic_Package_Declaration + or else Nkind (P) = N_Generic_Subprogram_Declaration + then + return P; + + elsif Nkind (P) = N_Package_Body + or else Nkind (P) = N_Subprogram_Body + then + Spec := Corresponding_Spec (P); + + if Present (Spec) then + Decl := Unit_Declaration_Node (Spec); + + if Nkind (Decl) = N_Generic_Package_Declaration + or else Nkind (Decl) = N_Generic_Subprogram_Declaration + then + return Decl; + end if; + end if; + end if; + + P := Parent (P); + end loop; + + return Empty; + end Enclosing_Generic_Unit; + + ------------------------------- + -- Enclosing_Lib_Unit_Entity -- + ------------------------------- + + function Enclosing_Lib_Unit_Entity return Entity_Id is + Unit_Entity : Entity_Id := Current_Scope; + + begin + -- Look for enclosing library unit entity by following scope links. + -- Equivalent to, but faster than indexing through the scope stack. + + while (Present (Scope (Unit_Entity)) + and then Scope (Unit_Entity) /= Standard_Standard) + and not Is_Child_Unit (Unit_Entity) + loop + Unit_Entity := Scope (Unit_Entity); + end loop; + + return Unit_Entity; + end Enclosing_Lib_Unit_Entity; + + ----------------------------- + -- Enclosing_Lib_Unit_Node -- + ----------------------------- + + function Enclosing_Lib_Unit_Node (N : Node_Id) return Node_Id is + Current_Node : Node_Id := N; + + begin + while Present (Current_Node) + and then Nkind (Current_Node) /= N_Compilation_Unit + loop + Current_Node := Parent (Current_Node); + end loop; + + if Nkind (Current_Node) /= N_Compilation_Unit then + return Empty; + end if; + + return Current_Node; + end Enclosing_Lib_Unit_Node; + + -------------------------- + -- Enclosing_Subprogram -- + -------------------------- + + function Enclosing_Subprogram (E : Entity_Id) return Entity_Id is + Dynamic_Scope : constant Entity_Id := Enclosing_Dynamic_Scope (E); + + begin + if Dynamic_Scope = Standard_Standard then + return Empty; + + elsif Ekind (Dynamic_Scope) = E_Subprogram_Body then + return Corresponding_Spec (Parent (Parent (Dynamic_Scope))); + + elsif Ekind (Dynamic_Scope) = E_Block then + return Enclosing_Subprogram (Dynamic_Scope); + + elsif Ekind (Dynamic_Scope) = E_Task_Type then + return Get_Task_Body_Procedure (Dynamic_Scope); + + elsif Convention (Dynamic_Scope) = Convention_Protected then + return Protected_Body_Subprogram (Dynamic_Scope); + + else + return Dynamic_Scope; + end if; + end Enclosing_Subprogram; + + ------------------------ + -- Ensure_Freeze_Node -- + ------------------------ + + procedure Ensure_Freeze_Node (E : Entity_Id) is + FN : Node_Id; + + begin + if No (Freeze_Node (E)) then + FN := Make_Freeze_Entity (Sloc (E)); + Set_Has_Delayed_Freeze (E); + Set_Freeze_Node (E, FN); + Set_Access_Types_To_Process (FN, No_Elist); + Set_TSS_Elist (FN, No_Elist); + Set_Entity (FN, E); + end if; + end Ensure_Freeze_Node; + + ---------------- + -- Enter_Name -- + ---------------- + + procedure Enter_Name (Def_Id : Entity_Id) is + C : constant Entity_Id := Current_Entity (Def_Id); + E : constant Entity_Id := Current_Entity_In_Scope (Def_Id); + S : constant Entity_Id := Current_Scope; + + function Is_Private_Component_Renaming (N : Node_Id) return Boolean; + -- Recognize a renaming declaration that is introduced for private + -- components of a protected type. We treat these as weak declarations + -- so that they are overridden by entities with the same name that + -- come from source, such as formals or local variables of a given + -- protected declaration. + + ----------------------------------- + -- Is_Private_Component_Renaming -- + ----------------------------------- + + function Is_Private_Component_Renaming (N : Node_Id) return Boolean is + begin + return not Comes_From_Source (N) + and then not Comes_From_Source (Current_Scope) + and then Nkind (N) = N_Object_Renaming_Declaration; + end Is_Private_Component_Renaming; + + -- Start of processing for Enter_Name + + begin + Generate_Definition (Def_Id); + + -- Add new name to current scope declarations. Check for duplicate + -- declaration, which may or may not be a genuine error. + + if Present (E) then + + -- Case of previous entity entered because of a missing declaration + -- or else a bad subtype indication. Best is to use the new entity, + -- and make the previous one invisible. + + if Etype (E) = Any_Type then + Set_Is_Immediately_Visible (E, False); + + -- Case of renaming declaration constructed for package instances. + -- if there is an explicit declaration with the same identifier, + -- the renaming is not immediately visible any longer, but remains + -- visible through selected component notation. + + elsif Nkind (Parent (E)) = N_Package_Renaming_Declaration + and then not Comes_From_Source (E) + then + Set_Is_Immediately_Visible (E, False); + + -- The new entity may be the package renaming, which has the same + -- same name as a generic formal which has been seen already. + + elsif Nkind (Parent (Def_Id)) = N_Package_Renaming_Declaration + and then not Comes_From_Source (Def_Id) + then + Set_Is_Immediately_Visible (E, False); + + -- For a fat pointer corresponding to a remote access to subprogram, + -- we use the same identifier as the RAS type, so that the proper + -- name appears in the stub. This type is only retrieved through + -- the RAS type and never by visibility, and is not added to the + -- visibility list (see below). + + elsif Nkind (Parent (Def_Id)) = N_Full_Type_Declaration + and then Present (Corresponding_Remote_Type (Def_Id)) + then + null; + + -- A controller component for a type extension overrides the + -- inherited component. + + elsif Chars (E) = Name_uController then + null; + + -- Case of an implicit operation or derived literal. The new entity + -- hides the implicit one, which is removed from all visibility, + -- i.e. the entity list of its scope, and homonym chain of its name. + + elsif (Is_Overloadable (E) and then Is_Inherited_Operation (E)) + or else Is_Internal (E) + then + declare + Prev : Entity_Id; + Prev_Vis : Entity_Id; + Decl : constant Node_Id := Parent (E); + + begin + -- If E is an implicit declaration, it cannot be the first + -- entity in the scope. + + Prev := First_Entity (Current_Scope); + + while Present (Prev) + and then Next_Entity (Prev) /= E + loop + Next_Entity (Prev); + end loop; + + if No (Prev) then + + -- If E is not on the entity chain of the current scope, + -- it is an implicit declaration in the generic formal + -- part of a generic subprogram. When analyzing the body, + -- the generic formals are visible but not on the entity + -- chain of the subprogram. The new entity will become + -- the visible one in the body. + + pragma Assert + (Nkind (Parent (Decl)) = N_Generic_Subprogram_Declaration); + null; + + else + Set_Next_Entity (Prev, Next_Entity (E)); + + if No (Next_Entity (Prev)) then + Set_Last_Entity (Current_Scope, Prev); + end if; + + if E = Current_Entity (E) then + Prev_Vis := Empty; + + else + Prev_Vis := Current_Entity (E); + while Homonym (Prev_Vis) /= E loop + Prev_Vis := Homonym (Prev_Vis); + end loop; + end if; + + if Present (Prev_Vis) then + + -- Skip E in the visibility chain + + Set_Homonym (Prev_Vis, Homonym (E)); + + else + Set_Name_Entity_Id (Chars (E), Homonym (E)); + end if; + end if; + end; + + -- This section of code could use a comment ??? + + elsif Present (Etype (E)) + and then Is_Concurrent_Type (Etype (E)) + and then E = Def_Id + then + return; + + elsif Is_Private_Component_Renaming (Parent (Def_Id)) then + return; + + -- In the body or private part of an instance, a type extension + -- may introduce a component with the same name as that of an + -- actual. The legality rule is not enforced, but the semantics + -- of the full type with two components of the same name are not + -- clear at this point ??? + + elsif In_Instance_Not_Visible then + null; + + -- When compiling a package body, some child units may have become + -- visible. They cannot conflict with local entities that hide them. + + elsif Is_Child_Unit (E) + and then In_Open_Scopes (Scope (E)) + and then not Is_Immediately_Visible (E) + then + null; + + -- Conversely, with front-end inlining we may compile the parent + -- body first, and a child unit subsequently. The context is now + -- the parent spec, and body entities are not visible. + + elsif Is_Child_Unit (Def_Id) + and then Is_Package_Body_Entity (E) + and then not In_Package_Body (Current_Scope) + then + null; + + -- Case of genuine duplicate declaration + + else + Error_Msg_Sloc := Sloc (E); + + -- If the previous declaration is an incomplete type declaration + -- this may be an attempt to complete it with a private type. + -- The following avoids confusing cascaded errors. + + if Nkind (Parent (E)) = N_Incomplete_Type_Declaration + and then Nkind (Parent (Def_Id)) = N_Private_Type_Declaration + then + Error_Msg_N + ("incomplete type cannot be completed" & + " with a private declaration", + Parent (Def_Id)); + Set_Is_Immediately_Visible (E, False); + Set_Full_View (E, Def_Id); + + elsif Ekind (E) = E_Discriminant + and then Present (Scope (Def_Id)) + and then Scope (Def_Id) /= Current_Scope + then + -- An inherited component of a record conflicts with + -- a new discriminant. The discriminant is inserted first + -- in the scope, but the error should be posted on it, not + -- on the component. + + Error_Msg_Sloc := Sloc (Def_Id); + Error_Msg_N ("& conflicts with declaration#", E); + return; + + -- If the name of the unit appears in its own context clause, + -- a dummy package with the name has already been created, and + -- the error emitted. Try to continue quietly. + + elsif Error_Posted (E) + and then Sloc (E) = No_Location + and then Nkind (Parent (E)) = N_Package_Specification + and then Current_Scope = Standard_Standard + then + Set_Scope (Def_Id, Current_Scope); + return; + + else + Error_Msg_N ("& conflicts with declaration#", Def_Id); + + -- Avoid cascaded messages with duplicate components in + -- derived types. + + if Ekind (E) = E_Component + or else Ekind (E) = E_Discriminant + then + return; + end if; + end if; + + if Nkind (Parent (Parent (Def_Id))) + = N_Generic_Subprogram_Declaration + and then Def_Id = + Defining_Entity (Specification (Parent (Parent (Def_Id)))) + then + Error_Msg_N ("\generic units cannot be overloaded", Def_Id); + end if; + + -- If entity is in standard, then we are in trouble, because + -- it means that we have a library package with a duplicated + -- name. That's hard to recover from, so abort! + + if S = Standard_Standard then + raise Unrecoverable_Error; + + -- Otherwise we continue with the declaration. Having two + -- identical declarations should not cause us too much trouble! + + else + null; + end if; + end if; + end if; + + -- If we fall through, declaration is OK , or OK enough to continue + + -- If Def_Id is a discriminant or a record component we are in the + -- midst of inheriting components in a derived record definition. + -- Preserve their Ekind and Etype. + + if Ekind (Def_Id) = E_Discriminant + or else Ekind (Def_Id) = E_Component + then + null; + + -- If a type is already set, leave it alone (happens whey a type + -- declaration is reanalyzed following a call to the optimizer) + + elsif Present (Etype (Def_Id)) then + null; + + -- Otherwise, the kind E_Void insures that premature uses of the entity + -- will be detected. Any_Type insures that no cascaded errors will occur + + else + Set_Ekind (Def_Id, E_Void); + Set_Etype (Def_Id, Any_Type); + end if; + + -- Inherited discriminants and components in derived record types are + -- immediately visible. Itypes are not. + + if Ekind (Def_Id) = E_Discriminant + or else Ekind (Def_Id) = E_Component + or else (No (Corresponding_Remote_Type (Def_Id)) + and then not Is_Itype (Def_Id)) + then + Set_Is_Immediately_Visible (Def_Id); + Set_Current_Entity (Def_Id); + end if; + + Set_Homonym (Def_Id, C); + Append_Entity (Def_Id, S); + Set_Public_Status (Def_Id); + + -- Warn if new entity hides an old one + + if Warn_On_Hiding + and then Present (C) + and then Length_Of_Name (Chars (C)) /= 1 + and then Comes_From_Source (C) + and then Comes_From_Source (Def_Id) + and then In_Extended_Main_Source_Unit (Def_Id) + then + Error_Msg_Sloc := Sloc (C); + Error_Msg_N ("declaration hides &#?", Def_Id); + end if; + end Enter_Name; + + -------------------------- + -- Explain_Limited_Type -- + -------------------------- + + procedure Explain_Limited_Type (T : Entity_Id; N : Node_Id) is + C : Entity_Id; + + begin + -- For array, component type must be limited + + if Is_Array_Type (T) then + Error_Msg_Node_2 := T; + Error_Msg_NE + ("component type& of type& is limited", N, Component_Type (T)); + Explain_Limited_Type (Component_Type (T), N); + + elsif Is_Record_Type (T) then + + -- No need for extra messages if explicit limited record + + if Is_Limited_Record (Base_Type (T)) then + return; + end if; + + -- Otherwise find a limited component. Check only components that + -- come from source, or inherited components that appear in the + -- source of the ancestor. + + C := First_Component (T); + while Present (C) loop + if Is_Limited_Type (Etype (C)) + and then + (Comes_From_Source (C) + or else + (Present (Original_Record_Component (C)) + and then + Comes_From_Source (Original_Record_Component (C)))) + then + Error_Msg_Node_2 := T; + Error_Msg_NE ("\component& of type& has limited type", N, C); + Explain_Limited_Type (Etype (C), N); + return; + end if; + + Next_Component (C); + end loop; + + -- The type may be declared explicitly limited, even if no component + -- of it is limited, in which case we fall out of the loop. + return; + end if; + end Explain_Limited_Type; + + ------------------------------------- + -- Find_Corresponding_Discriminant -- + ------------------------------------- + + function Find_Corresponding_Discriminant + (Id : Node_Id; + Typ : Entity_Id) return Entity_Id + is + Par_Disc : Entity_Id; + Old_Disc : Entity_Id; + New_Disc : Entity_Id; + + begin + Par_Disc := Original_Record_Component (Original_Discriminant (Id)); + + -- The original type may currently be private, and the discriminant + -- only appear on its full view. + + if Is_Private_Type (Scope (Par_Disc)) + and then not Has_Discriminants (Scope (Par_Disc)) + and then Present (Full_View (Scope (Par_Disc))) + then + Old_Disc := First_Discriminant (Full_View (Scope (Par_Disc))); + else + Old_Disc := First_Discriminant (Scope (Par_Disc)); + end if; + + if Is_Class_Wide_Type (Typ) then + New_Disc := First_Discriminant (Root_Type (Typ)); + else + New_Disc := First_Discriminant (Typ); + end if; + + while Present (Old_Disc) and then Present (New_Disc) loop + if Old_Disc = Par_Disc then + return New_Disc; + else + Next_Discriminant (Old_Disc); + Next_Discriminant (New_Disc); + end if; + end loop; + + -- Should always find it + + raise Program_Error; + end Find_Corresponding_Discriminant; + + ----------------------------- + -- Find_Static_Alternative -- + ----------------------------- + + function Find_Static_Alternative (N : Node_Id) return Node_Id is + Expr : constant Node_Id := Expression (N); + Val : constant Uint := Expr_Value (Expr); + Alt : Node_Id; + Choice : Node_Id; + + begin + Alt := First (Alternatives (N)); + + Search : loop + if Nkind (Alt) /= N_Pragma then + Choice := First (Discrete_Choices (Alt)); + + while Present (Choice) loop + + -- Others choice, always matches + + if Nkind (Choice) = N_Others_Choice then + exit Search; + + -- Range, check if value is in the range + + elsif Nkind (Choice) = N_Range then + exit Search when + Val >= Expr_Value (Low_Bound (Choice)) + and then + Val <= Expr_Value (High_Bound (Choice)); + + -- Choice is a subtype name. Note that we know it must + -- be a static subtype, since otherwise it would have + -- been diagnosed as illegal. + + elsif Is_Entity_Name (Choice) + and then Is_Type (Entity (Choice)) + then + exit Search when Is_In_Range (Expr, Etype (Choice)); + + -- Choice is a subtype indication + + elsif Nkind (Choice) = N_Subtype_Indication then + declare + C : constant Node_Id := Constraint (Choice); + R : constant Node_Id := Range_Expression (C); + + begin + exit Search when + Val >= Expr_Value (Low_Bound (R)) + and then + Val <= Expr_Value (High_Bound (R)); + end; + + -- Choice is a simple expression + + else + exit Search when Val = Expr_Value (Choice); + end if; + + Next (Choice); + end loop; + end if; + + Next (Alt); + pragma Assert (Present (Alt)); + end loop Search; + + -- The above loop *must* terminate by finding a match, since + -- we know the case statement is valid, and the value of the + -- expression is known at compile time. When we fall out of + -- the loop, Alt points to the alternative that we know will + -- be selected at run time. + + return Alt; + end Find_Static_Alternative; + + ------------------ + -- First_Actual -- + ------------------ + + function First_Actual (Node : Node_Id) return Node_Id is + N : Node_Id; + + begin + if No (Parameter_Associations (Node)) then + return Empty; + end if; + + N := First (Parameter_Associations (Node)); + + if Nkind (N) = N_Parameter_Association then + return First_Named_Actual (Node); + else + return N; + end if; + end First_Actual; + + ------------------------- + -- Full_Qualified_Name -- + ------------------------- + + function Full_Qualified_Name (E : Entity_Id) return String_Id is + Res : String_Id; + pragma Warnings (Off, Res); + + function Internal_Full_Qualified_Name (E : Entity_Id) return String_Id; + -- Compute recursively the qualified name without NUL at the end + + ---------------------------------- + -- Internal_Full_Qualified_Name -- + ---------------------------------- + + function Internal_Full_Qualified_Name (E : Entity_Id) return String_Id is + Ent : Entity_Id := E; + Parent_Name : String_Id := No_String; + + begin + -- Deals properly with child units + + if Nkind (Ent) = N_Defining_Program_Unit_Name then + Ent := Defining_Identifier (Ent); + end if; + + -- Compute qualification recursively (only "Standard" has no scope) + + if Present (Scope (Scope (Ent))) then + Parent_Name := Internal_Full_Qualified_Name (Scope (Ent)); + end if; + + -- Every entity should have a name except some expanded blocks + -- don't bother about those. + + if Chars (Ent) = No_Name then + return Parent_Name; + end if; + + -- Add a period between Name and qualification + + if Parent_Name /= No_String then + Start_String (Parent_Name); + Store_String_Char (Get_Char_Code ('.')); + + else + Start_String; + end if; + + -- Generates the entity name in upper case + + Get_Decoded_Name_String (Chars (Ent)); + Set_All_Upper_Case; + Store_String_Chars (Name_Buffer (1 .. Name_Len)); + return End_String; + end Internal_Full_Qualified_Name; + + -- Start of processing for Full_Qualified_Name + + begin + Res := Internal_Full_Qualified_Name (E); + Store_String_Char (Get_Char_Code (ASCII.nul)); + return End_String; + end Full_Qualified_Name; + + ----------------------- + -- Gather_Components -- + ----------------------- + + procedure Gather_Components + (Typ : Entity_Id; + Comp_List : Node_Id; + Governed_By : List_Id; + Into : Elist_Id; + Report_Errors : out Boolean) + is + Assoc : Node_Id; + Variant : Node_Id; + Discrete_Choice : Node_Id; + Comp_Item : Node_Id; + + Discrim : Entity_Id; + Discrim_Name : Node_Id; + Discrim_Value : Node_Id; + + begin + Report_Errors := False; + + if No (Comp_List) or else Null_Present (Comp_List) then + return; + + elsif Present (Component_Items (Comp_List)) then + Comp_Item := First (Component_Items (Comp_List)); + + else + Comp_Item := Empty; + end if; + + while Present (Comp_Item) loop + + -- Skip the tag of a tagged record, the interface tags, as well + -- as all items that are not user components (anonymous types, + -- rep clauses, Parent field, controller field). + + if Nkind (Comp_Item) = N_Component_Declaration then + declare + Comp : constant Entity_Id := Defining_Identifier (Comp_Item); + begin + if not Is_Tag (Comp) + and then Chars (Comp) /= Name_uParent + and then Chars (Comp) /= Name_uController + then + Append_Elmt (Comp, Into); + end if; + end; + end if; + + Next (Comp_Item); + end loop; + + if No (Variant_Part (Comp_List)) then + return; + else + Discrim_Name := Name (Variant_Part (Comp_List)); + Variant := First_Non_Pragma (Variants (Variant_Part (Comp_List))); + end if; + + -- Look for the discriminant that governs this variant part. + -- The discriminant *must* be in the Governed_By List + + Assoc := First (Governed_By); + Find_Constraint : loop + Discrim := First (Choices (Assoc)); + exit Find_Constraint when Chars (Discrim_Name) = Chars (Discrim) + or else (Present (Corresponding_Discriminant (Entity (Discrim))) + and then + Chars (Corresponding_Discriminant (Entity (Discrim))) + = Chars (Discrim_Name)) + or else Chars (Original_Record_Component (Entity (Discrim))) + = Chars (Discrim_Name); + + if No (Next (Assoc)) then + if not Is_Constrained (Typ) + and then Is_Derived_Type (Typ) + and then Present (Stored_Constraint (Typ)) + then + + -- If the type is a tagged type with inherited discriminants, + -- use the stored constraint on the parent in order to find + -- the values of discriminants that are otherwise hidden by an + -- explicit constraint. Renamed discriminants are handled in + -- the code above. + + -- If several parent discriminants are renamed by a single + -- discriminant of the derived type, the call to obtain the + -- Corresponding_Discriminant field only retrieves the last + -- of them. We recover the constraint on the others from the + -- Stored_Constraint as well. + + declare + D : Entity_Id; + C : Elmt_Id; + + begin + D := First_Discriminant (Etype (Typ)); + C := First_Elmt (Stored_Constraint (Typ)); + + while Present (D) + and then Present (C) + loop + if Chars (Discrim_Name) = Chars (D) then + if Is_Entity_Name (Node (C)) + and then Entity (Node (C)) = Entity (Discrim) + then + -- D is renamed by Discrim, whose value is + -- given in Assoc. + + null; + + else + Assoc := + Make_Component_Association (Sloc (Typ), + New_List + (New_Occurrence_Of (D, Sloc (Typ))), + Duplicate_Subexpr_No_Checks (Node (C))); + end if; + exit Find_Constraint; + end if; + + D := Next_Discriminant (D); + Next_Elmt (C); + end loop; + end; + end if; + end if; + + if No (Next (Assoc)) then + Error_Msg_NE (" missing value for discriminant&", + First (Governed_By), Discrim_Name); + Report_Errors := True; + return; + end if; + + Next (Assoc); + end loop Find_Constraint; + + Discrim_Value := Expression (Assoc); + + if not Is_OK_Static_Expression (Discrim_Value) then + Error_Msg_FE + ("value for discriminant & must be static!", + Discrim_Value, Discrim); + Why_Not_Static (Discrim_Value); + Report_Errors := True; + return; + end if; + + Search_For_Discriminant_Value : declare + Low : Node_Id; + High : Node_Id; + + UI_High : Uint; + UI_Low : Uint; + UI_Discrim_Value : constant Uint := Expr_Value (Discrim_Value); + + begin + Find_Discrete_Value : while Present (Variant) loop + Discrete_Choice := First (Discrete_Choices (Variant)); + while Present (Discrete_Choice) loop + + exit Find_Discrete_Value when + Nkind (Discrete_Choice) = N_Others_Choice; + + Get_Index_Bounds (Discrete_Choice, Low, High); + + UI_Low := Expr_Value (Low); + UI_High := Expr_Value (High); + + exit Find_Discrete_Value when + UI_Low <= UI_Discrim_Value + and then + UI_High >= UI_Discrim_Value; + + Next (Discrete_Choice); + end loop; + + Next_Non_Pragma (Variant); + end loop Find_Discrete_Value; + end Search_For_Discriminant_Value; + + if No (Variant) then + Error_Msg_NE + ("value of discriminant & is out of range", Discrim_Value, Discrim); + Report_Errors := True; + return; + end if; + + -- If we have found the corresponding choice, recursively add its + -- components to the Into list. + + Gather_Components (Empty, + Component_List (Variant), Governed_By, Into, Report_Errors); + end Gather_Components; + + ------------------------ + -- Get_Actual_Subtype -- + ------------------------ + + function Get_Actual_Subtype (N : Node_Id) return Entity_Id is + Typ : constant Entity_Id := Etype (N); + Utyp : Entity_Id := Underlying_Type (Typ); + Decl : Node_Id; + Atyp : Entity_Id; + + begin + if No (Utyp) then + Utyp := Typ; + end if; + + -- If what we have is an identifier that references a subprogram + -- formal, or a variable or constant object, then we get the actual + -- subtype from the referenced entity if one has been built. + + if Nkind (N) = N_Identifier + and then + (Is_Formal (Entity (N)) + or else Ekind (Entity (N)) = E_Constant + or else Ekind (Entity (N)) = E_Variable) + and then Present (Actual_Subtype (Entity (N))) + then + return Actual_Subtype (Entity (N)); + + -- Actual subtype of unchecked union is always itself. We never need + -- the "real" actual subtype. If we did, we couldn't get it anyway + -- because the discriminant is not available. The restrictions on + -- Unchecked_Union are designed to make sure that this is OK. + + elsif Is_Unchecked_Union (Base_Type (Utyp)) then + return Typ; + + -- Here for the unconstrained case, we must find actual subtype + -- No actual subtype is available, so we must build it on the fly. + + -- Checking the type, not the underlying type, for constrainedness + -- seems to be necessary. Maybe all the tests should be on the type??? + + elsif (not Is_Constrained (Typ)) + and then (Is_Array_Type (Utyp) + or else (Is_Record_Type (Utyp) + and then Has_Discriminants (Utyp))) + and then not Has_Unknown_Discriminants (Utyp) + and then not (Ekind (Utyp) = E_String_Literal_Subtype) + then + -- Nothing to do if in default expression + + if In_Default_Expression then + return Typ; + + elsif Is_Private_Type (Typ) + and then not Has_Discriminants (Typ) + then + -- If the type has no discriminants, there is no subtype to + -- build, even if the underlying type is discriminated. + + return Typ; + + -- Else build the actual subtype + + else + Decl := Build_Actual_Subtype (Typ, N); + Atyp := Defining_Identifier (Decl); + + -- If Build_Actual_Subtype generated a new declaration then use it + + if Atyp /= Typ then + + -- The actual subtype is an Itype, so analyze the declaration, + -- but do not attach it to the tree, to get the type defined. + + Set_Parent (Decl, N); + Set_Is_Itype (Atyp); + Analyze (Decl, Suppress => All_Checks); + Set_Associated_Node_For_Itype (Atyp, N); + Set_Has_Delayed_Freeze (Atyp, False); + + -- We need to freeze the actual subtype immediately. This is + -- needed, because otherwise this Itype will not get frozen + -- at all, and it is always safe to freeze on creation because + -- any associated types must be frozen at this point. + + Freeze_Itype (Atyp, N); + return Atyp; + + -- Otherwise we did not build a declaration, so return original + + else + return Typ; + end if; + end if; + + -- For all remaining cases, the actual subtype is the same as + -- the nominal type. + + else + return Typ; + end if; + end Get_Actual_Subtype; + + ------------------------------------- + -- Get_Actual_Subtype_If_Available -- + ------------------------------------- + + function Get_Actual_Subtype_If_Available (N : Node_Id) return Entity_Id is + Typ : constant Entity_Id := Etype (N); + + begin + -- If what we have is an identifier that references a subprogram + -- formal, or a variable or constant object, then we get the actual + -- subtype from the referenced entity if one has been built. + + if Nkind (N) = N_Identifier + and then + (Is_Formal (Entity (N)) + or else Ekind (Entity (N)) = E_Constant + or else Ekind (Entity (N)) = E_Variable) + and then Present (Actual_Subtype (Entity (N))) + then + return Actual_Subtype (Entity (N)); + + -- Otherwise the Etype of N is returned unchanged + + else + return Typ; + end if; + end Get_Actual_Subtype_If_Available; + + ------------------------------- + -- Get_Default_External_Name -- + ------------------------------- + + function Get_Default_External_Name (E : Node_Or_Entity_Id) return Node_Id is + begin + Get_Decoded_Name_String (Chars (E)); + + if Opt.External_Name_Imp_Casing = Uppercase then + Set_Casing (All_Upper_Case); + else + Set_Casing (All_Lower_Case); + end if; + + return + Make_String_Literal (Sloc (E), + Strval => String_From_Name_Buffer); + end Get_Default_External_Name; + + --------------------------- + -- Get_Enum_Lit_From_Pos -- + --------------------------- + + function Get_Enum_Lit_From_Pos + (T : Entity_Id; + Pos : Uint; + Loc : Source_Ptr) return Node_Id + is + Lit : Node_Id; + + begin + -- In the case where the literal is of type Character, Wide_Character + -- or Wide_Wide_Character or of a type derived from them, there needs + -- to be some special handling since there is no explicit chain of + -- literals to search. Instead, an N_Character_Literal node is created + -- with the appropriate Char_Code and Chars fields. + + if Root_Type (T) = Standard_Character + or else Root_Type (T) = Standard_Wide_Character + or else Root_Type (T) = Standard_Wide_Wide_Character + then + Set_Character_Literal_Name (UI_To_CC (Pos)); + return + Make_Character_Literal (Loc, + Chars => Name_Find, + Char_Literal_Value => Pos); + + -- For all other cases, we have a complete table of literals, and + -- we simply iterate through the chain of literal until the one + -- with the desired position value is found. + -- + + else + Lit := First_Literal (Base_Type (T)); + for J in 1 .. UI_To_Int (Pos) loop + Next_Literal (Lit); + end loop; + + return New_Occurrence_Of (Lit, Loc); + end if; + end Get_Enum_Lit_From_Pos; + + ------------------------ + -- Get_Generic_Entity -- + ------------------------ + + function Get_Generic_Entity (N : Node_Id) return Entity_Id is + Ent : constant Entity_Id := Entity (Name (N)); + begin + if Present (Renamed_Object (Ent)) then + return Renamed_Object (Ent); + else + return Ent; + end if; + end Get_Generic_Entity; + + ---------------------- + -- Get_Index_Bounds -- + ---------------------- + + procedure Get_Index_Bounds (N : Node_Id; L, H : out Node_Id) is + Kind : constant Node_Kind := Nkind (N); + R : Node_Id; + + begin + if Kind = N_Range then + L := Low_Bound (N); + H := High_Bound (N); + + elsif Kind = N_Subtype_Indication then + R := Range_Expression (Constraint (N)); + + if R = Error then + L := Error; + H := Error; + return; + + else + L := Low_Bound (Range_Expression (Constraint (N))); + H := High_Bound (Range_Expression (Constraint (N))); + end if; + + elsif Is_Entity_Name (N) and then Is_Type (Entity (N)) then + if Error_Posted (Scalar_Range (Entity (N))) then + L := Error; + H := Error; + + elsif Nkind (Scalar_Range (Entity (N))) = N_Subtype_Indication then + Get_Index_Bounds (Scalar_Range (Entity (N)), L, H); + + else + L := Low_Bound (Scalar_Range (Entity (N))); + H := High_Bound (Scalar_Range (Entity (N))); + end if; + + else + -- N is an expression, indicating a range with one value + + L := N; + H := N; + end if; + end Get_Index_Bounds; + + ---------------------------------- + -- Get_Library_Unit_Name_string -- + ---------------------------------- + + procedure Get_Library_Unit_Name_String (Decl_Node : Node_Id) is + Unit_Name_Id : constant Unit_Name_Type := Get_Unit_Name (Decl_Node); + + begin + Get_Unit_Name_String (Unit_Name_Id); + + -- Remove seven last character (" (spec)" or " (body)") + + Name_Len := Name_Len - 7; + pragma Assert (Name_Buffer (Name_Len + 1) = ' '); + end Get_Library_Unit_Name_String; + + ------------------------ + -- Get_Name_Entity_Id -- + ------------------------ + + function Get_Name_Entity_Id (Id : Name_Id) return Entity_Id is + begin + return Entity_Id (Get_Name_Table_Info (Id)); + end Get_Name_Entity_Id; + + --------------------------- + -- Get_Referenced_Object -- + --------------------------- + + function Get_Referenced_Object (N : Node_Id) return Node_Id is + R : Node_Id := N; + + begin + while Is_Entity_Name (R) + and then Present (Renamed_Object (Entity (R))) + loop + R := Renamed_Object (Entity (R)); + end loop; + + return R; + end Get_Referenced_Object; + + ------------------------- + -- Get_Subprogram_Body -- + ------------------------- + + function Get_Subprogram_Body (E : Entity_Id) return Node_Id is + Decl : Node_Id; + + begin + Decl := Unit_Declaration_Node (E); + + if Nkind (Decl) = N_Subprogram_Body then + return Decl; + + -- The below comment is bad, because it is possible for + -- Nkind (Decl) to be an N_Subprogram_Body_Stub ??? + + else -- Nkind (Decl) = N_Subprogram_Declaration + + if Present (Corresponding_Body (Decl)) then + return Unit_Declaration_Node (Corresponding_Body (Decl)); + + -- Imported subprogram case + + else + return Empty; + end if; + end if; + end Get_Subprogram_Body; + + ----------------------------- + -- Get_Task_Body_Procedure -- + ----------------------------- + + function Get_Task_Body_Procedure (E : Entity_Id) return Node_Id is + begin + -- Note: A task type may be the completion of a private type with + -- discriminants. when performing elaboration checks on a task + -- declaration, the current view of the type may be the private one, + -- and the procedure that holds the body of the task is held in its + -- underlying type. + + return Task_Body_Procedure (Underlying_Type (Root_Type (E))); + end Get_Task_Body_Procedure; + + ----------------------- + -- Has_Access_Values -- + ----------------------- + + function Has_Access_Values (T : Entity_Id) return Boolean is + Typ : constant Entity_Id := Underlying_Type (T); + + begin + -- Case of a private type which is not completed yet. This can only + -- happen in the case of a generic format type appearing directly, or + -- as a component of the type to which this function is being applied + -- at the top level. Return False in this case, since we certainly do + -- not know that the type contains access types. + + if No (Typ) then + return False; + + elsif Is_Access_Type (Typ) then + return True; + + elsif Is_Array_Type (Typ) then + return Has_Access_Values (Component_Type (Typ)); + + elsif Is_Record_Type (Typ) then + declare + Comp : Entity_Id; + + begin + Comp := First_Entity (Typ); + while Present (Comp) loop + if (Ekind (Comp) = E_Component + or else + Ekind (Comp) = E_Discriminant) + and then Has_Access_Values (Etype (Comp)) + then + return True; + end if; + + Next_Entity (Comp); + end loop; + end; + + return False; + + else + return False; + end if; + end Has_Access_Values; + + ---------------------- + -- Has_Declarations -- + ---------------------- + + function Has_Declarations (N : Node_Id) return Boolean is + K : constant Node_Kind := Nkind (N); + begin + return K = N_Accept_Statement + or else K = N_Block_Statement + or else K = N_Compilation_Unit_Aux + or else K = N_Entry_Body + or else K = N_Package_Body + or else K = N_Protected_Body + or else K = N_Subprogram_Body + or else K = N_Task_Body + or else K = N_Package_Specification; + end Has_Declarations; + + ------------------------------------------- + -- Has_Discriminant_Dependent_Constraint -- + ------------------------------------------- + + function Has_Discriminant_Dependent_Constraint + (Comp : Entity_Id) return Boolean + is + Comp_Decl : constant Node_Id := Parent (Comp); + Subt_Indic : constant Node_Id := + Subtype_Indication (Component_Definition (Comp_Decl)); + Constr : Node_Id; + Assn : Node_Id; + + begin + if Nkind (Subt_Indic) = N_Subtype_Indication then + Constr := Constraint (Subt_Indic); + + if Nkind (Constr) = N_Index_Or_Discriminant_Constraint then + Assn := First (Constraints (Constr)); + while Present (Assn) loop + case Nkind (Assn) is + when N_Subtype_Indication | + N_Range | + N_Identifier + => + if Depends_On_Discriminant (Assn) then + return True; + end if; + + when N_Discriminant_Association => + if Depends_On_Discriminant (Expression (Assn)) then + return True; + end if; + + when others => + null; + + end case; + + Next (Assn); + end loop; + end if; + end if; + + return False; + end Has_Discriminant_Dependent_Constraint; + + -------------------- + -- Has_Infinities -- + -------------------- + + function Has_Infinities (E : Entity_Id) return Boolean is + begin + return + Is_Floating_Point_Type (E) + and then Nkind (Scalar_Range (E)) = N_Range + and then Includes_Infinities (Scalar_Range (E)); + end Has_Infinities; + + ------------------------ + -- Has_Null_Extension -- + ------------------------ + + function Has_Null_Extension (T : Entity_Id) return Boolean is + B : constant Entity_Id := Base_Type (T); + Comps : Node_Id; + Ext : Node_Id; + + begin + if Nkind (Parent (B)) = N_Full_Type_Declaration + and then Present (Record_Extension_Part (Type_Definition (Parent (B)))) + then + Ext := Record_Extension_Part (Type_Definition (Parent (B))); + + if Present (Ext) then + if Null_Present (Ext) then + return True; + else + Comps := Component_List (Ext); + + -- The null component list is rewritten during analysis to + -- include the parent component. Any other component indicates + -- that the extension was not originally null. + + return Null_Present (Comps) + or else No (Next (First (Component_Items (Comps)))); + end if; + else + return False; + end if; + + else + return False; + end if; + end Has_Null_Extension; + + --------------------------- + -- Has_Private_Component -- + --------------------------- + + function Has_Private_Component (Type_Id : Entity_Id) return Boolean is + Btype : Entity_Id := Base_Type (Type_Id); + Component : Entity_Id; + + begin + if Error_Posted (Type_Id) + or else Error_Posted (Btype) + then + return False; + end if; + + if Is_Class_Wide_Type (Btype) then + Btype := Root_Type (Btype); + end if; + + if Is_Private_Type (Btype) then + declare + UT : constant Entity_Id := Underlying_Type (Btype); + begin + if No (UT) then + + if No (Full_View (Btype)) then + return not Is_Generic_Type (Btype) + and then not Is_Generic_Type (Root_Type (Btype)); + + else + return not Is_Generic_Type (Root_Type (Full_View (Btype))); + end if; + + else + return not Is_Frozen (UT) and then Has_Private_Component (UT); + end if; + end; + elsif Is_Array_Type (Btype) then + return Has_Private_Component (Component_Type (Btype)); + + elsif Is_Record_Type (Btype) then + + Component := First_Component (Btype); + while Present (Component) loop + + if Has_Private_Component (Etype (Component)) then + return True; + end if; + + Next_Component (Component); + end loop; + + return False; + + elsif Is_Protected_Type (Btype) + and then Present (Corresponding_Record_Type (Btype)) + then + return Has_Private_Component (Corresponding_Record_Type (Btype)); + + else + return False; + end if; + end Has_Private_Component; + + ---------------- + -- Has_Stream -- + ---------------- + + function Has_Stream (T : Entity_Id) return Boolean is + E : Entity_Id; + + begin + if No (T) then + return False; + + elsif Is_RTE (Root_Type (T), RE_Root_Stream_Type) then + return True; + + elsif Is_Array_Type (T) then + return Has_Stream (Component_Type (T)); + + elsif Is_Record_Type (T) then + E := First_Component (T); + while Present (E) loop + if Has_Stream (Etype (E)) then + return True; + else + Next_Component (E); + end if; + end loop; + + return False; + + elsif Is_Private_Type (T) then + return Has_Stream (Underlying_Type (T)); + + else + return False; + end if; + end Has_Stream; + + -------------------------- + -- Has_Tagged_Component -- + -------------------------- + + function Has_Tagged_Component (Typ : Entity_Id) return Boolean is + Comp : Entity_Id; + + begin + if Is_Private_Type (Typ) + and then Present (Underlying_Type (Typ)) + then + return Has_Tagged_Component (Underlying_Type (Typ)); + + elsif Is_Array_Type (Typ) then + return Has_Tagged_Component (Component_Type (Typ)); + + elsif Is_Tagged_Type (Typ) then + return True; + + elsif Is_Record_Type (Typ) then + Comp := First_Component (Typ); + + while Present (Comp) loop + if Has_Tagged_Component (Etype (Comp)) then + return True; + end if; + + Comp := Next_Component (Typ); + end loop; + + return False; + + else + return False; + end if; + end Has_Tagged_Component; + + ----------------- + -- In_Instance -- + ----------------- + + function In_Instance return Boolean is + S : Entity_Id := Current_Scope; + + begin + while Present (S) + and then S /= Standard_Standard + loop + if (Ekind (S) = E_Function + or else Ekind (S) = E_Package + or else Ekind (S) = E_Procedure) + and then Is_Generic_Instance (S) + then + return True; + end if; + + S := Scope (S); + end loop; + + return False; + end In_Instance; + + ---------------------- + -- In_Instance_Body -- + ---------------------- + + function In_Instance_Body return Boolean is + S : Entity_Id := Current_Scope; + + begin + while Present (S) + and then S /= Standard_Standard + loop + if (Ekind (S) = E_Function + or else Ekind (S) = E_Procedure) + and then Is_Generic_Instance (S) + then + return True; + + elsif Ekind (S) = E_Package + and then In_Package_Body (S) + and then Is_Generic_Instance (S) + then + return True; + end if; + + S := Scope (S); + end loop; + + return False; + end In_Instance_Body; + + ----------------------------- + -- In_Instance_Not_Visible -- + ----------------------------- + + function In_Instance_Not_Visible return Boolean is + S : Entity_Id := Current_Scope; + + begin + while Present (S) + and then S /= Standard_Standard + loop + if (Ekind (S) = E_Function + or else Ekind (S) = E_Procedure) + and then Is_Generic_Instance (S) + then + return True; + + elsif Ekind (S) = E_Package + and then (In_Package_Body (S) or else In_Private_Part (S)) + and then Is_Generic_Instance (S) + then + return True; + end if; + + S := Scope (S); + end loop; + + return False; + end In_Instance_Not_Visible; + + ------------------------------ + -- In_Instance_Visible_Part -- + ------------------------------ + + function In_Instance_Visible_Part return Boolean is + S : Entity_Id := Current_Scope; + + begin + while Present (S) + and then S /= Standard_Standard + loop + if Ekind (S) = E_Package + and then Is_Generic_Instance (S) + and then not In_Package_Body (S) + and then not In_Private_Part (S) + then + return True; + end if; + + S := Scope (S); + end loop; + + return False; + end In_Instance_Visible_Part; + + ---------------------- + -- In_Packiage_Body -- + ---------------------- + + function In_Package_Body return Boolean is + S : Entity_Id := Current_Scope; + + begin + while Present (S) + and then S /= Standard_Standard + loop + if Ekind (S) = E_Package + and then In_Package_Body (S) + then + return True; + else + S := Scope (S); + end if; + end loop; + + return False; + end In_Package_Body; + + -------------------------------------- + -- In_Subprogram_Or_Concurrent_Unit -- + -------------------------------------- + + function In_Subprogram_Or_Concurrent_Unit return Boolean is + E : Entity_Id; + K : Entity_Kind; + + begin + -- Use scope chain to check successively outer scopes + + E := Current_Scope; + loop + K := Ekind (E); + + if K in Subprogram_Kind + or else K in Concurrent_Kind + or else K in Generic_Subprogram_Kind + then + return True; + + elsif E = Standard_Standard then + return False; + end if; + + E := Scope (E); + end loop; + end In_Subprogram_Or_Concurrent_Unit; + + --------------------- + -- In_Visible_Part -- + --------------------- + + function In_Visible_Part (Scope_Id : Entity_Id) return Boolean is + begin + return + Is_Package_Or_Generic_Package (Scope_Id) + and then In_Open_Scopes (Scope_Id) + and then not In_Package_Body (Scope_Id) + and then not In_Private_Part (Scope_Id); + end In_Visible_Part; + + --------------------------------- + -- Insert_Explicit_Dereference -- + --------------------------------- + + procedure Insert_Explicit_Dereference (N : Node_Id) is + New_Prefix : constant Node_Id := Relocate_Node (N); + Ent : Entity_Id := Empty; + Pref : Node_Id; + I : Interp_Index; + It : Interp; + T : Entity_Id; + + begin + Save_Interps (N, New_Prefix); + Rewrite (N, + Make_Explicit_Dereference (Sloc (N), Prefix => New_Prefix)); + + Set_Etype (N, Designated_Type (Etype (New_Prefix))); + + if Is_Overloaded (New_Prefix) then + + -- The deference is also overloaded, and its interpretations are the + -- designated types of the interpretations of the original node. + + Set_Etype (N, Any_Type); + Get_First_Interp (New_Prefix, I, It); + + while Present (It.Nam) loop + T := It.Typ; + + if Is_Access_Type (T) then + Add_One_Interp (N, Designated_Type (T), Designated_Type (T)); + end if; + + Get_Next_Interp (I, It); + end loop; + + End_Interp_List; + + else + -- Prefix is unambiguous: mark the original prefix (which might + -- Come_From_Source) as a reference, since the new (relocated) one + -- won't be taken into account. + + if Is_Entity_Name (New_Prefix) then + Ent := Entity (New_Prefix); + + -- For a retrieval of a subcomponent of some composite object, + -- retrieve the ultimate entity if there is one. + + elsif Nkind (New_Prefix) = N_Selected_Component + or else Nkind (New_Prefix) = N_Indexed_Component + then + Pref := Prefix (New_Prefix); + + while Present (Pref) + and then + (Nkind (Pref) = N_Selected_Component + or else Nkind (Pref) = N_Indexed_Component) + loop + Pref := Prefix (Pref); + end loop; + + if Present (Pref) and then Is_Entity_Name (Pref) then + Ent := Entity (Pref); + end if; + end if; + + if Present (Ent) then + Generate_Reference (Ent, New_Prefix); + end if; + end if; + end Insert_Explicit_Dereference; + + ------------------- + -- Is_AAMP_Float -- + ------------------- + + function Is_AAMP_Float (E : Entity_Id) return Boolean is + begin + pragma Assert (Is_Type (E)); + + return AAMP_On_Target + and then Is_Floating_Point_Type (E) + and then E = Base_Type (E); + end Is_AAMP_Float; + + ------------------------- + -- Is_Actual_Parameter -- + ------------------------- + + function Is_Actual_Parameter (N : Node_Id) return Boolean is + PK : constant Node_Kind := Nkind (Parent (N)); + + begin + case PK is + when N_Parameter_Association => + return N = Explicit_Actual_Parameter (Parent (N)); + + when N_Function_Call | N_Procedure_Call_Statement => + return Is_List_Member (N) + and then + List_Containing (N) = Parameter_Associations (Parent (N)); + + when others => + return False; + end case; + end Is_Actual_Parameter; + + --------------------- + -- Is_Aliased_View -- + --------------------- + + function Is_Aliased_View (Obj : Node_Id) return Boolean is + E : Entity_Id; + + begin + if Is_Entity_Name (Obj) then + + E := Entity (Obj); + + return + (Is_Object (E) + and then + (Is_Aliased (E) + or else (Present (Renamed_Object (E)) + and then Is_Aliased_View (Renamed_Object (E))))) + + or else ((Is_Formal (E) + or else Ekind (E) = E_Generic_In_Out_Parameter + or else Ekind (E) = E_Generic_In_Parameter) + and then Is_Tagged_Type (Etype (E))) + + or else ((Ekind (E) = E_Task_Type + or else Ekind (E) = E_Protected_Type) + and then In_Open_Scopes (E)) + + -- Current instance of type + + or else (Is_Type (E) and then E = Current_Scope) + or else (Is_Incomplete_Or_Private_Type (E) + and then Full_View (E) = Current_Scope); + + elsif Nkind (Obj) = N_Selected_Component then + return Is_Aliased (Entity (Selector_Name (Obj))); + + elsif Nkind (Obj) = N_Indexed_Component then + return Has_Aliased_Components (Etype (Prefix (Obj))) + or else + (Is_Access_Type (Etype (Prefix (Obj))) + and then + Has_Aliased_Components + (Designated_Type (Etype (Prefix (Obj))))); + + elsif Nkind (Obj) = N_Unchecked_Type_Conversion + or else Nkind (Obj) = N_Type_Conversion + then + return Is_Tagged_Type (Etype (Obj)) + and then Is_Aliased_View (Expression (Obj)); + + elsif Nkind (Obj) = N_Explicit_Dereference then + return Nkind (Original_Node (Obj)) /= N_Function_Call; + + else + return False; + end if; + end Is_Aliased_View; + + ------------------------- + -- Is_Ancestor_Package -- + ------------------------- + + function Is_Ancestor_Package + (E1 : Entity_Id; + E2 : Entity_Id) return Boolean + is + Par : Entity_Id; + + begin + Par := E2; + while Present (Par) + and then Par /= Standard_Standard + loop + if Par = E1 then + return True; + end if; + + Par := Scope (Par); + end loop; + + return False; + end Is_Ancestor_Package; + + ---------------------- + -- Is_Atomic_Object -- + ---------------------- + + function Is_Atomic_Object (N : Node_Id) return Boolean is + + function Object_Has_Atomic_Components (N : Node_Id) return Boolean; + -- Determines if given object has atomic components + + function Is_Atomic_Prefix (N : Node_Id) return Boolean; + -- If prefix is an implicit dereference, examine designated type + + function Is_Atomic_Prefix (N : Node_Id) return Boolean is + begin + if Is_Access_Type (Etype (N)) then + return + Has_Atomic_Components (Designated_Type (Etype (N))); + else + return Object_Has_Atomic_Components (N); + end if; + end Is_Atomic_Prefix; + + function Object_Has_Atomic_Components (N : Node_Id) return Boolean is + begin + if Has_Atomic_Components (Etype (N)) + or else Is_Atomic (Etype (N)) + then + return True; + + elsif Is_Entity_Name (N) + and then (Has_Atomic_Components (Entity (N)) + or else Is_Atomic (Entity (N))) + then + return True; + + elsif Nkind (N) = N_Indexed_Component + or else Nkind (N) = N_Selected_Component + then + return Is_Atomic_Prefix (Prefix (N)); + + else + return False; + end if; + end Object_Has_Atomic_Components; + + -- Start of processing for Is_Atomic_Object + + begin + if Is_Atomic (Etype (N)) + or else (Is_Entity_Name (N) and then Is_Atomic (Entity (N))) + then + return True; + + elsif Nkind (N) = N_Indexed_Component + or else Nkind (N) = N_Selected_Component + then + return Is_Atomic_Prefix (Prefix (N)); + + else + return False; + end if; + end Is_Atomic_Object; + + -------------------------------------- + -- Is_Controlling_Limited_Procedure -- + -------------------------------------- + + function Is_Controlling_Limited_Procedure + (Proc_Nam : Entity_Id) return Boolean + is + Param_Typ : Entity_Id := Empty; + + begin + if Ekind (Proc_Nam) = E_Procedure + and then Present (Parameter_Specifications (Parent (Proc_Nam))) + then + Param_Typ := Etype (Parameter_Type (First ( + Parameter_Specifications (Parent (Proc_Nam))))); + + -- In this case where an Itype was created, the procedure call has been + -- rewritten. + + elsif Present (Associated_Node_For_Itype (Proc_Nam)) + and then Present (Original_Node (Associated_Node_For_Itype (Proc_Nam))) + and then + Present (Parameter_Associations + (Associated_Node_For_Itype (Proc_Nam))) + then + Param_Typ := + Etype (First (Parameter_Associations + (Associated_Node_For_Itype (Proc_Nam)))); + end if; + + if Present (Param_Typ) then + return + Is_Interface (Param_Typ) + and then Is_Limited_Record (Param_Typ); + end if; + + return False; + end Is_Controlling_Limited_Procedure; + + ---------------------------------------------- + -- Is_Dependent_Component_Of_Mutable_Object -- + ---------------------------------------------- + + function Is_Dependent_Component_Of_Mutable_Object + (Object : Node_Id) return Boolean + is + P : Node_Id; + Prefix_Type : Entity_Id; + P_Aliased : Boolean := False; + Comp : Entity_Id; + + function Is_Declared_Within_Variant (Comp : Entity_Id) return Boolean; + -- Returns True if and only if Comp is declared within a variant part + + -------------------------------- + -- Is_Declared_Within_Variant -- + -------------------------------- + + function Is_Declared_Within_Variant (Comp : Entity_Id) return Boolean is + Comp_Decl : constant Node_Id := Parent (Comp); + Comp_List : constant Node_Id := Parent (Comp_Decl); + begin + return Nkind (Parent (Comp_List)) = N_Variant; + end Is_Declared_Within_Variant; + + -- Start of processing for Is_Dependent_Component_Of_Mutable_Object + + begin + if Is_Variable (Object) then + + if Nkind (Object) = N_Selected_Component then + P := Prefix (Object); + Prefix_Type := Etype (P); + + if Is_Entity_Name (P) then + + if Ekind (Entity (P)) = E_Generic_In_Out_Parameter then + Prefix_Type := Base_Type (Prefix_Type); + end if; + + if Is_Aliased (Entity (P)) then + P_Aliased := True; + end if; + + -- A discriminant check on a selected component may be + -- expanded into a dereference when removing side-effects. + -- Recover the original node and its type, which may be + -- unconstrained. + + elsif Nkind (P) = N_Explicit_Dereference + and then not (Comes_From_Source (P)) + then + P := Original_Node (P); + Prefix_Type := Etype (P); + + else + -- Check for prefix being an aliased component ??? + null; + + end if; + + -- A heap object is constrained by its initial value + + -- Ada 2005 AI-363:if the designated type is a type with a + -- constrained partial view, the resulting heap object is not + -- constrained, and a renaming of the component is now unsafe. + + if Is_Access_Type (Prefix_Type) + and then + not Has_Constrained_Partial_View + (Designated_Type (Prefix_Type)) + then + return False; + + elsif Nkind (P) = N_Explicit_Dereference + and then not Has_Constrained_Partial_View (Prefix_Type) + then + return False; + end if; + + Comp := + Original_Record_Component (Entity (Selector_Name (Object))); + + -- As per AI-0017, the renaming is illegal in a generic body, + -- even if the subtype is indefinite. + + if not Is_Constrained (Prefix_Type) + and then (not Is_Indefinite_Subtype (Prefix_Type) + or else + (Is_Generic_Type (Prefix_Type) + and then Ekind (Current_Scope) = E_Generic_Package + and then In_Package_Body (Current_Scope))) + + and then (Is_Declared_Within_Variant (Comp) + or else Has_Discriminant_Dependent_Constraint (Comp)) + and then not P_Aliased + then + return True; + + else + return + Is_Dependent_Component_Of_Mutable_Object (Prefix (Object)); + + end if; + + elsif Nkind (Object) = N_Indexed_Component + or else Nkind (Object) = N_Slice + then + return Is_Dependent_Component_Of_Mutable_Object (Prefix (Object)); + + -- A type conversion that Is_Variable is a view conversion: + -- go back to the denoted object. + + elsif Nkind (Object) = N_Type_Conversion then + return + Is_Dependent_Component_Of_Mutable_Object (Expression (Object)); + end if; + end if; + + return False; + end Is_Dependent_Component_Of_Mutable_Object; + + --------------------- + -- Is_Dereferenced -- + --------------------- + + function Is_Dereferenced (N : Node_Id) return Boolean is + P : constant Node_Id := Parent (N); + begin + return + (Nkind (P) = N_Selected_Component + or else + Nkind (P) = N_Explicit_Dereference + or else + Nkind (P) = N_Indexed_Component + or else + Nkind (P) = N_Slice) + and then Prefix (P) = N; + end Is_Dereferenced; + + ---------------------- + -- Is_Descendent_Of -- + ---------------------- + + function Is_Descendent_Of (T1 : Entity_Id; T2 : Entity_Id) return Boolean is + T : Entity_Id; + Etyp : Entity_Id; + + begin + pragma Assert (Nkind (T1) in N_Entity); + pragma Assert (Nkind (T2) in N_Entity); + + T := Base_Type (T1); + + -- Immediate return if the types match + + if T = T2 then + return True; + + -- Comment needed here ??? + + elsif Ekind (T) = E_Class_Wide_Type then + return Etype (T) = T2; + + -- All other cases + + else + loop + Etyp := Etype (T); + + -- Done if we found the type we are looking for + + if Etyp = T2 then + return True; + + -- Done if no more derivations to check + + elsif T = T1 + or else T = Etyp + then + return False; + + -- Following test catches error cases resulting from prev errors + + elsif No (Etyp) then + return False; + + elsif Is_Private_Type (T) and then Etyp = Full_View (T) then + return False; + + elsif Is_Private_Type (Etyp) and then Full_View (Etyp) = T then + return False; + end if; + + T := Base_Type (Etyp); + end loop; + end if; + + raise Program_Error; + end Is_Descendent_Of; + + ------------------------------ + -- Is_Descendent_Of_Address -- + ------------------------------ + + function Is_Descendent_Of_Address (T1 : Entity_Id) return Boolean is + begin + -- If Address has not been loaded, answer must be False + + if not RTU_Loaded (System) then + return False; + + -- Otherwise we can get the entity we are interested in without + -- causing an unwanted dependency on System, and do the test. + + else + return Is_Descendent_Of (T1, Base_Type (RTE (RE_Address))); + end if; + end Is_Descendent_Of_Address; + + -------------- + -- Is_False -- + -------------- + + function Is_False (U : Uint) return Boolean is + begin + return (U = 0); + end Is_False; + + --------------------------- + -- Is_Fixed_Model_Number -- + --------------------------- + + function Is_Fixed_Model_Number (U : Ureal; T : Entity_Id) return Boolean is + S : constant Ureal := Small_Value (T); + M : Urealp.Save_Mark; + R : Boolean; + begin + M := Urealp.Mark; + R := (U = UR_Trunc (U / S) * S); + Urealp.Release (M); + return R; + end Is_Fixed_Model_Number; + + ------------------------------- + -- Is_Fully_Initialized_Type -- + ------------------------------- + + function Is_Fully_Initialized_Type (Typ : Entity_Id) return Boolean is + begin + if Is_Scalar_Type (Typ) then + return False; + + elsif Is_Access_Type (Typ) then + return True; + + elsif Is_Array_Type (Typ) then + if Is_Fully_Initialized_Type (Component_Type (Typ)) then + return True; + end if; + + -- An interesting case, if we have a constrained type one of whose + -- bounds is known to be null, then there are no elements to be + -- initialized, so all the elements are initialized! + + if Is_Constrained (Typ) then + declare + Indx : Node_Id; + Indx_Typ : Entity_Id; + Lbd, Hbd : Node_Id; + + begin + Indx := First_Index (Typ); + while Present (Indx) loop + + if Etype (Indx) = Any_Type then + return False; + + -- If index is a range, use directly + + elsif Nkind (Indx) = N_Range then + Lbd := Low_Bound (Indx); + Hbd := High_Bound (Indx); + + else + Indx_Typ := Etype (Indx); + + if Is_Private_Type (Indx_Typ) then + Indx_Typ := Full_View (Indx_Typ); + end if; + + if No (Indx_Typ) then + return False; + else + Lbd := Type_Low_Bound (Indx_Typ); + Hbd := Type_High_Bound (Indx_Typ); + end if; + end if; + + if Compile_Time_Known_Value (Lbd) + and then Compile_Time_Known_Value (Hbd) + then + if Expr_Value (Hbd) < Expr_Value (Lbd) then + return True; + end if; + end if; + + Next_Index (Indx); + end loop; + end; + end if; + + -- If no null indexes, then type is not fully initialized + + return False; + + -- Record types + + elsif Is_Record_Type (Typ) then + if Has_Discriminants (Typ) + and then + Present (Discriminant_Default_Value (First_Discriminant (Typ))) + and then Is_Fully_Initialized_Variant (Typ) + then + return True; + end if; + + -- Controlled records are considered to be fully initialized if + -- there is a user defined Initialize routine. This may not be + -- entirely correct, but as the spec notes, we are guessing here + -- what is best from the point of view of issuing warnings. + + if Is_Controlled (Typ) then + declare + Utyp : constant Entity_Id := Underlying_Type (Typ); + + begin + if Present (Utyp) then + declare + Init : constant Entity_Id := + (Find_Prim_Op + (Underlying_Type (Typ), Name_Initialize)); + + begin + if Present (Init) + and then Comes_From_Source (Init) + and then not + Is_Predefined_File_Name + (File_Name (Get_Source_File_Index (Sloc (Init)))) + then + return True; + + elsif Has_Null_Extension (Typ) + and then + Is_Fully_Initialized_Type + (Etype (Base_Type (Typ))) + then + return True; + end if; + end; + end if; + end; + end if; + + -- Otherwise see if all record components are initialized + + declare + Ent : Entity_Id; + + begin + Ent := First_Entity (Typ); + + while Present (Ent) loop + if Chars (Ent) = Name_uController then + null; + + elsif Ekind (Ent) = E_Component + and then (No (Parent (Ent)) + or else No (Expression (Parent (Ent)))) + and then not Is_Fully_Initialized_Type (Etype (Ent)) + then + return False; + end if; + + Next_Entity (Ent); + end loop; + end; + + -- No uninitialized components, so type is fully initialized. + -- Note that this catches the case of no components as well. + + return True; + + elsif Is_Concurrent_Type (Typ) then + return True; + + elsif Is_Private_Type (Typ) then + declare + U : constant Entity_Id := Underlying_Type (Typ); + + begin + if No (U) then + return False; + else + return Is_Fully_Initialized_Type (U); + end if; + end; + + else + return False; + end if; + end Is_Fully_Initialized_Type; + + ---------------------------------- + -- Is_Fully_Initialized_Variant -- + ---------------------------------- + + function Is_Fully_Initialized_Variant (Typ : Entity_Id) return Boolean is + Loc : constant Source_Ptr := Sloc (Typ); + Constraints : constant List_Id := New_List; + Components : constant Elist_Id := New_Elmt_List; + Comp_Elmt : Elmt_Id; + Comp_Id : Node_Id; + Comp_List : Node_Id; + Discr : Entity_Id; + Discr_Val : Node_Id; + Report_Errors : Boolean; + + begin + if Serious_Errors_Detected > 0 then + return False; + end if; + + if Is_Record_Type (Typ) + and then Nkind (Parent (Typ)) = N_Full_Type_Declaration + and then Nkind (Type_Definition (Parent (Typ))) = N_Record_Definition + then + Comp_List := Component_List (Type_Definition (Parent (Typ))); + Discr := First_Discriminant (Typ); + + while Present (Discr) loop + if Nkind (Parent (Discr)) = N_Discriminant_Specification then + Discr_Val := Expression (Parent (Discr)); + + if Present (Discr_Val) + and then Is_OK_Static_Expression (Discr_Val) + then + Append_To (Constraints, + Make_Component_Association (Loc, + Choices => New_List (New_Occurrence_Of (Discr, Loc)), + Expression => New_Copy (Discr_Val))); + else + return False; + end if; + else + return False; + end if; + + Next_Discriminant (Discr); + end loop; + + Gather_Components + (Typ => Typ, + Comp_List => Comp_List, + Governed_By => Constraints, + Into => Components, + Report_Errors => Report_Errors); + + -- Check that each component present is fully initialized + + Comp_Elmt := First_Elmt (Components); + + while Present (Comp_Elmt) loop + Comp_Id := Node (Comp_Elmt); + + if Ekind (Comp_Id) = E_Component + and then (No (Parent (Comp_Id)) + or else No (Expression (Parent (Comp_Id)))) + and then not Is_Fully_Initialized_Type (Etype (Comp_Id)) + then + return False; + end if; + + Next_Elmt (Comp_Elmt); + end loop; + + return True; + + elsif Is_Private_Type (Typ) then + declare + U : constant Entity_Id := Underlying_Type (Typ); + + begin + if No (U) then + return False; + else + return Is_Fully_Initialized_Variant (U); + end if; + end; + else + return False; + end if; + end Is_Fully_Initialized_Variant; + + ---------------------------- + -- Is_Inherited_Operation -- + ---------------------------- + + function Is_Inherited_Operation (E : Entity_Id) return Boolean is + Kind : constant Node_Kind := Nkind (Parent (E)); + begin + pragma Assert (Is_Overloadable (E)); + return Kind = N_Full_Type_Declaration + or else Kind = N_Private_Extension_Declaration + or else Kind = N_Subtype_Declaration + or else (Ekind (E) = E_Enumeration_Literal + and then Is_Derived_Type (Etype (E))); + end Is_Inherited_Operation; + + ----------------------------- + -- Is_Library_Level_Entity -- + ----------------------------- + + function Is_Library_Level_Entity (E : Entity_Id) return Boolean is + begin + -- The following is a small optimization, and it also handles + -- properly discriminals, which in task bodies might appear in + -- expressions before the corresponding procedure has been + -- created, and which therefore do not have an assigned scope. + + if Ekind (E) in Formal_Kind then + return False; + end if; + + -- Normal test is simply that the enclosing dynamic scope is Standard + + return Enclosing_Dynamic_Scope (E) = Standard_Standard; + end Is_Library_Level_Entity; + + --------------------------------- + -- Is_Local_Variable_Reference -- + --------------------------------- + + function Is_Local_Variable_Reference (Expr : Node_Id) return Boolean is + begin + if not Is_Entity_Name (Expr) then + return False; + + else + declare + Ent : constant Entity_Id := Entity (Expr); + Sub : constant Entity_Id := Enclosing_Subprogram (Ent); + begin + if Ekind (Ent) /= E_Variable + and then + Ekind (Ent) /= E_In_Out_Parameter + then + return False; + else + return Present (Sub) and then Sub = Current_Subprogram; + end if; + end; + end if; + end Is_Local_Variable_Reference; + + --------------- + -- Is_Lvalue -- + --------------- + + function Is_Lvalue (N : Node_Id) return Boolean is + P : constant Node_Id := Parent (N); + + begin + case Nkind (P) is + + -- Test left side of assignment + + when N_Assignment_Statement => + return N = Name (P); + + -- Test prefix of component or attribute + + when N_Attribute_Reference | + N_Expanded_Name | + N_Explicit_Dereference | + N_Indexed_Component | + N_Reference | + N_Selected_Component | + N_Slice => + return N = Prefix (P); + + -- Test subprogram parameter (we really should check the + -- parameter mode, but it is not worth the trouble) + + when N_Function_Call | + N_Procedure_Call_Statement | + N_Accept_Statement | + N_Parameter_Association => + return True; + + -- Test for appearing in a conversion that itself appears + -- in an lvalue context, since this should be an lvalue. + + when N_Type_Conversion => + return Is_Lvalue (P); + + -- Test for appearence in object renaming declaration + + when N_Object_Renaming_Declaration => + return True; + + -- All other references are definitely not Lvalues + + when others => + return False; + + end case; + end Is_Lvalue; + + ------------------------- + -- Is_Object_Reference -- + ------------------------- + + function Is_Object_Reference (N : Node_Id) return Boolean is + begin + if Is_Entity_Name (N) then + return Is_Object (Entity (N)); + + else + case Nkind (N) is + when N_Indexed_Component | N_Slice => + return + Is_Object_Reference (Prefix (N)) + or else Is_Access_Type (Etype (Prefix (N))); + + -- In Ada95, a function call is a constant object; a procedure + -- call is not. + + when N_Function_Call => + return Etype (N) /= Standard_Void_Type; + + -- A reference to the stream attribute Input is a function call + + when N_Attribute_Reference => + return Attribute_Name (N) = Name_Input; + + when N_Selected_Component => + return + Is_Object_Reference (Selector_Name (N)) + and then + (Is_Object_Reference (Prefix (N)) + or else Is_Access_Type (Etype (Prefix (N)))); + + when N_Explicit_Dereference => + return True; + + -- A view conversion of a tagged object is an object reference + + when N_Type_Conversion => + return Is_Tagged_Type (Etype (Subtype_Mark (N))) + and then Is_Tagged_Type (Etype (Expression (N))) + and then Is_Object_Reference (Expression (N)); + + -- An unchecked type conversion is considered to be an object if + -- the operand is an object (this construction arises only as a + -- result of expansion activities). + + when N_Unchecked_Type_Conversion => + return True; + + when others => + return False; + end case; + end if; + end Is_Object_Reference; + + ----------------------------------- + -- Is_OK_Variable_For_Out_Formal -- + ----------------------------------- + + function Is_OK_Variable_For_Out_Formal (AV : Node_Id) return Boolean is + begin + Note_Possible_Modification (AV); + + -- We must reject parenthesized variable names. The check for + -- Comes_From_Source is present because there are currently + -- cases where the compiler violates this rule (e.g. passing + -- a task object to its controlled Initialize routine). + + if Paren_Count (AV) > 0 and then Comes_From_Source (AV) then + return False; + + -- A variable is always allowed + + elsif Is_Variable (AV) then + return True; + + -- Unchecked conversions are allowed only if they come from the + -- generated code, which sometimes uses unchecked conversions for out + -- parameters in cases where code generation is unaffected. We tell + -- source unchecked conversions by seeing if they are rewrites of an + -- original Unchecked_Conversion function call, or of an explicit + -- conversion of a function call. + + elsif Nkind (AV) = N_Unchecked_Type_Conversion then + if Nkind (Original_Node (AV)) = N_Function_Call then + return False; + + elsif Comes_From_Source (AV) + and then Nkind (Original_Node (Expression (AV))) = N_Function_Call + then + return False; + + elsif Nkind (Original_Node (AV)) = N_Type_Conversion then + return Is_OK_Variable_For_Out_Formal (Expression (AV)); + + else + return True; + end if; + + -- Normal type conversions are allowed if argument is a variable + + elsif Nkind (AV) = N_Type_Conversion then + if Is_Variable (Expression (AV)) + and then Paren_Count (Expression (AV)) = 0 + then + Note_Possible_Modification (Expression (AV)); + return True; + + -- We also allow a non-parenthesized expression that raises + -- constraint error if it rewrites what used to be a variable + + elsif Raises_Constraint_Error (Expression (AV)) + and then Paren_Count (Expression (AV)) = 0 + and then Is_Variable (Original_Node (Expression (AV))) + then + return True; + + -- Type conversion of something other than a variable + + else + return False; + end if; + + -- If this node is rewritten, then test the original form, if that is + -- OK, then we consider the rewritten node OK (for example, if the + -- original node is a conversion, then Is_Variable will not be true + -- but we still want to allow the conversion if it converts a variable). + + elsif Original_Node (AV) /= AV then + return Is_OK_Variable_For_Out_Formal (Original_Node (AV)); + + -- All other non-variables are rejected + + else + return False; + end if; + end Is_OK_Variable_For_Out_Formal; + + ----------------------------------- + -- Is_Partially_Initialized_Type -- + ----------------------------------- + + function Is_Partially_Initialized_Type (Typ : Entity_Id) return Boolean is + begin + if Is_Scalar_Type (Typ) then + return False; + + elsif Is_Access_Type (Typ) then + return True; + + elsif Is_Array_Type (Typ) then + + -- If component type is partially initialized, so is array type + + if Is_Partially_Initialized_Type (Component_Type (Typ)) then + return True; + + -- Otherwise we are only partially initialized if we are fully + -- initialized (this is the empty array case, no point in us + -- duplicating that code here). + + else + return Is_Fully_Initialized_Type (Typ); + end if; + + elsif Is_Record_Type (Typ) then + + -- A discriminated type is always partially initialized + + if Has_Discriminants (Typ) then + return True; + + -- A tagged type is always partially initialized + + elsif Is_Tagged_Type (Typ) then + return True; + + -- Case of non-discriminated record + + else + declare + Ent : Entity_Id; + + Component_Present : Boolean := False; + -- Set True if at least one component is present. If no + -- components are present, then record type is fully + -- initialized (another odd case, like the null array). + + begin + -- Loop through components + + Ent := First_Entity (Typ); + while Present (Ent) loop + if Ekind (Ent) = E_Component then + Component_Present := True; + + -- If a component has an initialization expression then + -- the enclosing record type is partially initialized + + if Present (Parent (Ent)) + and then Present (Expression (Parent (Ent))) + then + return True; + + -- If a component is of a type which is itself partially + -- initialized, then the enclosing record type is also. + + elsif Is_Partially_Initialized_Type (Etype (Ent)) then + return True; + end if; + end if; + + Next_Entity (Ent); + end loop; + + -- No initialized components found. If we found any components + -- they were all uninitialized so the result is false. + + if Component_Present then + return False; + + -- But if we found no components, then all the components are + -- initialized so we consider the type to be initialized. + + else + return True; + end if; + end; + end if; + + -- Concurrent types are always fully initialized + + elsif Is_Concurrent_Type (Typ) then + return True; + + -- For a private type, go to underlying type. If there is no underlying + -- type then just assume this partially initialized. Not clear if this + -- can happen in a non-error case, but no harm in testing for this. + + elsif Is_Private_Type (Typ) then + declare + U : constant Entity_Id := Underlying_Type (Typ); + begin + if No (U) then + return True; + else + return Is_Partially_Initialized_Type (U); + end if; + end; + + -- For any other type (are there any?) assume partially initialized + + else + return True; + end if; + end Is_Partially_Initialized_Type; + + ------------------------------------ + -- Is_Potentially_Persistent_Type -- + ------------------------------------ + + function Is_Potentially_Persistent_Type (T : Entity_Id) return Boolean is + Comp : Entity_Id; + Indx : Node_Id; + + begin + -- For private type, test corrresponding full type + + if Is_Private_Type (T) then + return Is_Potentially_Persistent_Type (Full_View (T)); + + -- Scalar types are potentially persistent + + elsif Is_Scalar_Type (T) then + return True; + + -- Record type is potentially persistent if not tagged and the types of + -- all it components are potentially persistent, and no component has + -- an initialization expression. + + elsif Is_Record_Type (T) + and then not Is_Tagged_Type (T) + and then not Is_Partially_Initialized_Type (T) + then + Comp := First_Component (T); + while Present (Comp) loop + if not Is_Potentially_Persistent_Type (Etype (Comp)) then + return False; + else + Next_Entity (Comp); + end if; + end loop; + + return True; + + -- Array type is potentially persistent if its component type is + -- potentially persistent and if all its constraints are static. + + elsif Is_Array_Type (T) then + if not Is_Potentially_Persistent_Type (Component_Type (T)) then + return False; + end if; + + Indx := First_Index (T); + while Present (Indx) loop + if not Is_OK_Static_Subtype (Etype (Indx)) then + return False; + else + Next_Index (Indx); + end if; + end loop; + + return True; + + -- All other types are not potentially persistent + + else + return False; + end if; + end Is_Potentially_Persistent_Type; + + ----------------------------- + -- Is_RCI_Pkg_Spec_Or_Body -- + ----------------------------- + + function Is_RCI_Pkg_Spec_Or_Body (Cunit : Node_Id) return Boolean is + + function Is_RCI_Pkg_Decl_Cunit (Cunit : Node_Id) return Boolean; + -- Return True if the unit of Cunit is an RCI package declaration + + --------------------------- + -- Is_RCI_Pkg_Decl_Cunit -- + --------------------------- + + function Is_RCI_Pkg_Decl_Cunit (Cunit : Node_Id) return Boolean is + The_Unit : constant Node_Id := Unit (Cunit); + + begin + if Nkind (The_Unit) /= N_Package_Declaration then + return False; + end if; + + return Is_Remote_Call_Interface (Defining_Entity (The_Unit)); + end Is_RCI_Pkg_Decl_Cunit; + + -- Start of processing for Is_RCI_Pkg_Spec_Or_Body + + begin + return Is_RCI_Pkg_Decl_Cunit (Cunit) + or else + (Nkind (Unit (Cunit)) = N_Package_Body + and then Is_RCI_Pkg_Decl_Cunit (Library_Unit (Cunit))); + end Is_RCI_Pkg_Spec_Or_Body; + + ----------------------------------------- + -- Is_Remote_Access_To_Class_Wide_Type -- + ----------------------------------------- + + function Is_Remote_Access_To_Class_Wide_Type + (E : Entity_Id) return Boolean + is + D : Entity_Id; + + function Comes_From_Limited_Private_Type_Declaration + (E : Entity_Id) return Boolean; + -- Check that the type is declared by a limited type declaration, + -- or else is derived from a Remote_Type ancestor through private + -- extensions. + + ------------------------------------------------- + -- Comes_From_Limited_Private_Type_Declaration -- + ------------------------------------------------- + + function Comes_From_Limited_Private_Type_Declaration + (E : Entity_Id) return Boolean + is + N : constant Node_Id := Declaration_Node (E); + + begin + if Nkind (N) = N_Private_Type_Declaration + and then Limited_Present (N) + then + return True; + end if; + + if Nkind (N) = N_Private_Extension_Declaration then + return + Comes_From_Limited_Private_Type_Declaration (Etype (E)) + or else + (Is_Remote_Types (Etype (E)) + and then Is_Limited_Record (Etype (E)) + and then Has_Private_Declaration (Etype (E))); + end if; + + return False; + end Comes_From_Limited_Private_Type_Declaration; + + -- Start of processing for Is_Remote_Access_To_Class_Wide_Type + + begin + if not (Is_Remote_Call_Interface (E) + or else Is_Remote_Types (E)) + or else Ekind (E) /= E_General_Access_Type + then + return False; + end if; + + D := Designated_Type (E); + + if Ekind (D) /= E_Class_Wide_Type then + return False; + end if; + + return Comes_From_Limited_Private_Type_Declaration + (Defining_Identifier (Parent (D))); + end Is_Remote_Access_To_Class_Wide_Type; + + ----------------------------------------- + -- Is_Remote_Access_To_Subprogram_Type -- + ----------------------------------------- + + function Is_Remote_Access_To_Subprogram_Type + (E : Entity_Id) return Boolean + is + begin + return (Ekind (E) = E_Access_Subprogram_Type + or else (Ekind (E) = E_Record_Type + and then Present (Corresponding_Remote_Type (E)))) + and then (Is_Remote_Call_Interface (E) + or else Is_Remote_Types (E)); + end Is_Remote_Access_To_Subprogram_Type; + + -------------------- + -- Is_Remote_Call -- + -------------------- + + function Is_Remote_Call (N : Node_Id) return Boolean is + begin + if Nkind (N) /= N_Procedure_Call_Statement + and then Nkind (N) /= N_Function_Call + then + -- An entry call cannot be remote + + return False; + + elsif Nkind (Name (N)) in N_Has_Entity + and then Is_Remote_Call_Interface (Entity (Name (N))) + then + -- A subprogram declared in the spec of a RCI package is remote + + return True; + + elsif Nkind (Name (N)) = N_Explicit_Dereference + and then Is_Remote_Access_To_Subprogram_Type + (Etype (Prefix (Name (N)))) + then + -- The dereference of a RAS is a remote call + + return True; + + elsif Present (Controlling_Argument (N)) + and then Is_Remote_Access_To_Class_Wide_Type + (Etype (Controlling_Argument (N))) + then + -- Any primitive operation call with a controlling argument of + -- a RACW type is a remote call. + + return True; + end if; + + -- All other calls are local calls + + return False; + end Is_Remote_Call; + + ---------------------- + -- Is_Renamed_Entry -- + ---------------------- + + function Is_Renamed_Entry (Proc_Nam : Entity_Id) return Boolean is + Orig_Node : Node_Id := Empty; + Subp_Decl : Node_Id := Parent (Parent (Proc_Nam)); + + function Is_Entry (Nam : Node_Id) return Boolean; + -- Determine whether Nam is an entry. Traverse selectors + -- if there are nested selected components. + + -------------- + -- Is_Entry -- + -------------- + + function Is_Entry (Nam : Node_Id) return Boolean is + begin + if Nkind (Nam) = N_Selected_Component then + return Is_Entry (Selector_Name (Nam)); + end if; + + return Ekind (Entity (Nam)) = E_Entry; + end Is_Entry; + + -- Start of processing for Is_Renamed_Entry + + begin + if Present (Alias (Proc_Nam)) then + Subp_Decl := Parent (Parent (Alias (Proc_Nam))); + end if; + + -- Look for a rewritten subprogram renaming declaration + + if Nkind (Subp_Decl) = N_Subprogram_Declaration + and then Present (Original_Node (Subp_Decl)) + then + Orig_Node := Original_Node (Subp_Decl); + end if; + + -- The rewritten subprogram is actually an entry + + if Present (Orig_Node) + and then Nkind (Orig_Node) = N_Subprogram_Renaming_Declaration + and then Is_Entry (Name (Orig_Node)) + then + return True; + end if; + + return False; + end Is_Renamed_Entry; + + ---------------------- + -- Is_Selector_Name -- + ---------------------- + + function Is_Selector_Name (N : Node_Id) return Boolean is + begin + if not Is_List_Member (N) then + declare + P : constant Node_Id := Parent (N); + K : constant Node_Kind := Nkind (P); + begin + return + (K = N_Expanded_Name or else + K = N_Generic_Association or else + K = N_Parameter_Association or else + K = N_Selected_Component) + and then Selector_Name (P) = N; + end; + + else + declare + L : constant List_Id := List_Containing (N); + P : constant Node_Id := Parent (L); + begin + return (Nkind (P) = N_Discriminant_Association + and then Selector_Names (P) = L) + or else + (Nkind (P) = N_Component_Association + and then Choices (P) = L); + end; + end if; + end Is_Selector_Name; + + ------------------ + -- Is_Statement -- + ------------------ + + function Is_Statement (N : Node_Id) return Boolean is + begin + return + Nkind (N) in N_Statement_Other_Than_Procedure_Call + or else Nkind (N) = N_Procedure_Call_Statement; + end Is_Statement; + + ----------------- + -- Is_Transfer -- + ----------------- + + function Is_Transfer (N : Node_Id) return Boolean is + Kind : constant Node_Kind := Nkind (N); + + begin + if Kind = N_Return_Statement + or else + Kind = N_Goto_Statement + or else + Kind = N_Raise_Statement + or else + Kind = N_Requeue_Statement + then + return True; + + elsif (Kind = N_Exit_Statement or else Kind in N_Raise_xxx_Error) + and then No (Condition (N)) + then + return True; + + elsif Kind = N_Procedure_Call_Statement + and then Is_Entity_Name (Name (N)) + and then Present (Entity (Name (N))) + and then No_Return (Entity (Name (N))) + then + return True; + + elsif Nkind (Original_Node (N)) = N_Raise_Statement then + return True; + + else + return False; + end if; + end Is_Transfer; + + ------------- + -- Is_True -- + ------------- + + function Is_True (U : Uint) return Boolean is + begin + return (U /= 0); + end Is_True; + + ----------------- + -- Is_Variable -- + ----------------- + + function Is_Variable (N : Node_Id) return Boolean is + + Orig_Node : constant Node_Id := Original_Node (N); + -- We do the test on the original node, since this is basically a + -- test of syntactic categories, so it must not be disturbed by + -- whatever rewriting might have occurred. For example, an aggregate, + -- which is certainly NOT a variable, could be turned into a variable + -- by expansion. + + function In_Protected_Function (E : Entity_Id) return Boolean; + -- Within a protected function, the private components of the + -- enclosing protected type are constants. A function nested within + -- a (protected) procedure is not itself protected. + + function Is_Variable_Prefix (P : Node_Id) return Boolean; + -- Prefixes can involve implicit dereferences, in which case we + -- must test for the case of a reference of a constant access + -- type, which can never be a variable. + + --------------------------- + -- In_Protected_Function -- + --------------------------- + + function In_Protected_Function (E : Entity_Id) return Boolean is + Prot : constant Entity_Id := Scope (E); + S : Entity_Id; + + begin + if not Is_Protected_Type (Prot) then + return False; + else + S := Current_Scope; + while Present (S) and then S /= Prot loop + if Ekind (S) = E_Function + and then Scope (S) = Prot + then + return True; + end if; + + S := Scope (S); + end loop; + + return False; + end if; + end In_Protected_Function; + + ------------------------ + -- Is_Variable_Prefix -- + ------------------------ + + function Is_Variable_Prefix (P : Node_Id) return Boolean is + begin + if Is_Access_Type (Etype (P)) then + return not Is_Access_Constant (Root_Type (Etype (P))); + + -- For the case of an indexed component whose prefix has a packed + -- array type, the prefix has been rewritten into a type conversion. + -- Determine variable-ness from the converted expression. + + elsif Nkind (P) = N_Type_Conversion + and then not Comes_From_Source (P) + and then Is_Array_Type (Etype (P)) + and then Is_Packed (Etype (P)) + then + return Is_Variable (Expression (P)); + + else + return Is_Variable (P); + end if; + end Is_Variable_Prefix; + + -- Start of processing for Is_Variable + + begin + -- Definitely OK if Assignment_OK is set. Since this is something that + -- only gets set for expanded nodes, the test is on N, not Orig_Node. + + if Nkind (N) in N_Subexpr and then Assignment_OK (N) then + return True; + + -- Normally we go to the original node, but there is one exception + -- where we use the rewritten node, namely when it is an explicit + -- dereference. The generated code may rewrite a prefix which is an + -- access type with an explicit dereference. The dereference is a + -- variable, even though the original node may not be (since it could + -- be a constant of the access type). + + elsif Nkind (N) = N_Explicit_Dereference + and then Nkind (Orig_Node) /= N_Explicit_Dereference + and then Is_Access_Type (Etype (Orig_Node)) + then + return Is_Variable_Prefix (Original_Node (Prefix (N))); + + -- A function call is never a variable + + elsif Nkind (N) = N_Function_Call then + return False; + + -- All remaining checks use the original node + + elsif Is_Entity_Name (Orig_Node) then + declare + E : constant Entity_Id := Entity (Orig_Node); + K : constant Entity_Kind := Ekind (E); + + begin + return (K = E_Variable + and then Nkind (Parent (E)) /= N_Exception_Handler) + or else (K = E_Component + and then not In_Protected_Function (E)) + or else K = E_Out_Parameter + or else K = E_In_Out_Parameter + or else K = E_Generic_In_Out_Parameter + + -- Current instance of type: + + or else (Is_Type (E) and then In_Open_Scopes (E)) + or else (Is_Incomplete_Or_Private_Type (E) + and then In_Open_Scopes (Full_View (E))); + end; + + else + case Nkind (Orig_Node) is + when N_Indexed_Component | N_Slice => + return Is_Variable_Prefix (Prefix (Orig_Node)); + + when N_Selected_Component => + return Is_Variable_Prefix (Prefix (Orig_Node)) + and then Is_Variable (Selector_Name (Orig_Node)); + + -- For an explicit dereference, the type of the prefix cannot + -- be an access to constant or an access to subprogram. + + when N_Explicit_Dereference => + declare + Typ : constant Entity_Id := Etype (Prefix (Orig_Node)); + begin + return Is_Access_Type (Typ) + and then not Is_Access_Constant (Root_Type (Typ)) + and then Ekind (Typ) /= E_Access_Subprogram_Type; + end; + + -- The type conversion is the case where we do not deal with the + -- context dependent special case of an actual parameter. Thus + -- the type conversion is only considered a variable for the + -- purposes of this routine if the target type is tagged. However, + -- a type conversion is considered to be a variable if it does not + -- come from source (this deals for example with the conversions + -- of expressions to their actual subtypes). + + when N_Type_Conversion => + return Is_Variable (Expression (Orig_Node)) + and then + (not Comes_From_Source (Orig_Node) + or else + (Is_Tagged_Type (Etype (Subtype_Mark (Orig_Node))) + and then + Is_Tagged_Type (Etype (Expression (Orig_Node))))); + + -- GNAT allows an unchecked type conversion as a variable. This + -- only affects the generation of internal expanded code, since + -- calls to instantiations of Unchecked_Conversion are never + -- considered variables (since they are function calls). + -- This is also true for expression actions. + + when N_Unchecked_Type_Conversion => + return Is_Variable (Expression (Orig_Node)); + + when others => + return False; + end case; + end if; + end Is_Variable; + + ------------------------ + -- Is_Volatile_Object -- + ------------------------ + + function Is_Volatile_Object (N : Node_Id) return Boolean is + + function Object_Has_Volatile_Components (N : Node_Id) return Boolean; + -- Determines if given object has volatile components + + function Is_Volatile_Prefix (N : Node_Id) return Boolean; + -- If prefix is an implicit dereference, examine designated type + + ------------------------ + -- Is_Volatile_Prefix -- + ------------------------ + + function Is_Volatile_Prefix (N : Node_Id) return Boolean is + Typ : constant Entity_Id := Etype (N); + + begin + if Is_Access_Type (Typ) then + declare + Dtyp : constant Entity_Id := Designated_Type (Typ); + + begin + return Is_Volatile (Dtyp) + or else Has_Volatile_Components (Dtyp); + end; + + else + return Object_Has_Volatile_Components (N); + end if; + end Is_Volatile_Prefix; + + ------------------------------------ + -- Object_Has_Volatile_Components -- + ------------------------------------ + + function Object_Has_Volatile_Components (N : Node_Id) return Boolean is + Typ : constant Entity_Id := Etype (N); + + begin + if Is_Volatile (Typ) + or else Has_Volatile_Components (Typ) + then + return True; + + elsif Is_Entity_Name (N) + and then (Has_Volatile_Components (Entity (N)) + or else Is_Volatile (Entity (N))) + then + return True; + + elsif Nkind (N) = N_Indexed_Component + or else Nkind (N) = N_Selected_Component + then + return Is_Volatile_Prefix (Prefix (N)); + + else + return False; + end if; + end Object_Has_Volatile_Components; + + -- Start of processing for Is_Volatile_Object + + begin + if Is_Volatile (Etype (N)) + or else (Is_Entity_Name (N) and then Is_Volatile (Entity (N))) + then + return True; + + elsif Nkind (N) = N_Indexed_Component + or else Nkind (N) = N_Selected_Component + then + return Is_Volatile_Prefix (Prefix (N)); + + else + return False; + end if; + end Is_Volatile_Object; + + ------------------------- + -- Kill_Current_Values -- + ------------------------- + + procedure Kill_Current_Values (Ent : Entity_Id) is + begin + if Is_Object (Ent) then + Kill_Checks (Ent); + Set_Current_Value (Ent, Empty); + + if not Can_Never_Be_Null (Ent) then + Set_Is_Known_Non_Null (Ent, False); + end if; + + Set_Is_Known_Null (Ent, False); + end if; + end Kill_Current_Values; + + procedure Kill_Current_Values is + S : Entity_Id; + + procedure Kill_Current_Values_For_Entity_Chain (E : Entity_Id); + -- Clear current value for entity E and all entities chained to E + + ------------------------------------------ + -- Kill_Current_Values_For_Entity_Chain -- + ------------------------------------------ + + procedure Kill_Current_Values_For_Entity_Chain (E : Entity_Id) is + Ent : Entity_Id; + begin + Ent := E; + while Present (Ent) loop + Kill_Current_Values (Ent); + Next_Entity (Ent); + end loop; + end Kill_Current_Values_For_Entity_Chain; + + -- Start of processing for Kill_Current_Values + + begin + -- Kill all saved checks, a special case of killing saved values + + Kill_All_Checks; + + -- Loop through relevant scopes, which includes the current scope and + -- any parent scopes if the current scope is a block or a package. + + S := Current_Scope; + Scope_Loop : loop + + -- Clear current values of all entities in current scope + + Kill_Current_Values_For_Entity_Chain (First_Entity (S)); + + -- If scope is a package, also clear current values of all + -- private entities in the scope. + + if Ekind (S) = E_Package + or else + Ekind (S) = E_Generic_Package + or else + Is_Concurrent_Type (S) + then + Kill_Current_Values_For_Entity_Chain (First_Private_Entity (S)); + end if; + + -- If this is a block or nested package, deal with parent + + if Ekind (S) = E_Block + or else (Ekind (S) = E_Package + and then not Is_Library_Level_Entity (S)) + then + S := Scope (S); + else + exit Scope_Loop; + end if; + end loop Scope_Loop; + end Kill_Current_Values; + + -------------------------- + -- Kill_Size_Check_Code -- + -------------------------- + + procedure Kill_Size_Check_Code (E : Entity_Id) is + begin + if (Ekind (E) = E_Constant or else Ekind (E) = E_Variable) + and then Present (Size_Check_Code (E)) + then + Remove (Size_Check_Code (E)); + Set_Size_Check_Code (E, Empty); + end if; + end Kill_Size_Check_Code; + + ------------------------- + -- New_External_Entity -- + ------------------------- + + function New_External_Entity + (Kind : Entity_Kind; + Scope_Id : Entity_Id; + Sloc_Value : Source_Ptr; + Related_Id : Entity_Id; + Suffix : Character; + Suffix_Index : Nat := 0; + Prefix : Character := ' ') return Entity_Id + is + N : constant Entity_Id := + Make_Defining_Identifier (Sloc_Value, + New_External_Name + (Chars (Related_Id), Suffix, Suffix_Index, Prefix)); + + begin + Set_Ekind (N, Kind); + Set_Is_Internal (N, True); + Append_Entity (N, Scope_Id); + Set_Public_Status (N); + + if Kind in Type_Kind then + Init_Size_Align (N); + end if; + + return N; + end New_External_Entity; + + ------------------------- + -- New_Internal_Entity -- + ------------------------- + + function New_Internal_Entity + (Kind : Entity_Kind; + Scope_Id : Entity_Id; + Sloc_Value : Source_Ptr; + Id_Char : Character) return Entity_Id + is + N : constant Entity_Id := + Make_Defining_Identifier (Sloc_Value, New_Internal_Name (Id_Char)); + + begin + Set_Ekind (N, Kind); + Set_Is_Internal (N, True); + Append_Entity (N, Scope_Id); + + if Kind in Type_Kind then + Init_Size_Align (N); + end if; + + return N; + end New_Internal_Entity; + + ----------------- + -- Next_Actual -- + ----------------- + + function Next_Actual (Actual_Id : Node_Id) return Node_Id is + N : Node_Id; + + begin + -- If we are pointing at a positional parameter, it is a member of + -- a node list (the list of parameters), and the next parameter + -- is the next node on the list, unless we hit a parameter + -- association, in which case we shift to using the chain whose + -- head is the First_Named_Actual in the parent, and then is + -- threaded using the Next_Named_Actual of the Parameter_Association. + -- All this fiddling is because the original node list is in the + -- textual call order, and what we need is the declaration order. + + if Is_List_Member (Actual_Id) then + N := Next (Actual_Id); + + if Nkind (N) = N_Parameter_Association then + return First_Named_Actual (Parent (Actual_Id)); + else + return N; + end if; + + else + return Next_Named_Actual (Parent (Actual_Id)); + end if; + end Next_Actual; + + procedure Next_Actual (Actual_Id : in out Node_Id) is + begin + Actual_Id := Next_Actual (Actual_Id); + end Next_Actual; + + ----------------------- + -- Normalize_Actuals -- + ----------------------- + + -- Chain actuals according to formals of subprogram. If there are no named + -- associations, the chain is simply the list of Parameter Associations, + -- since the order is the same as the declaration order. If there are named + -- associations, then the First_Named_Actual field in the N_Function_Call + -- or N_Procedure_Call_Statement node points to the Parameter_Association + -- node for the parameter that comes first in declaration order. The + -- remaining named parameters are then chained in declaration order using + -- Next_Named_Actual. + + -- This routine also verifies that the number of actuals is compatible with + -- the number and default values of formals, but performs no type checking + -- (type checking is done by the caller). + + -- If the matching succeeds, Success is set to True and the caller proceeds + -- with type-checking. If the match is unsuccessful, then Success is set to + -- False, and the caller attempts a different interpretation, if there is + -- one. + + -- If the flag Report is on, the call is not overloaded, and a failure to + -- match can be reported here, rather than in the caller. + + procedure Normalize_Actuals + (N : Node_Id; + S : Entity_Id; + Report : Boolean; + Success : out Boolean) + is + Actuals : constant List_Id := Parameter_Associations (N); + Actual : Node_Id := Empty; + Formal : Entity_Id; + Last : Node_Id := Empty; + First_Named : Node_Id := Empty; + Found : Boolean; + + Formals_To_Match : Integer := 0; + Actuals_To_Match : Integer := 0; + + procedure Chain (A : Node_Id); + -- Add named actual at the proper place in the list, using the + -- Next_Named_Actual link. + + function Reporting return Boolean; + -- Determines if an error is to be reported. To report an error, we + -- need Report to be True, and also we do not report errors caused + -- by calls to init procs that occur within other init procs. Such + -- errors must always be cascaded errors, since if all the types are + -- declared correctly, the compiler will certainly build decent calls! + + ----------- + -- Chain -- + ----------- + + procedure Chain (A : Node_Id) is + begin + if No (Last) then + + -- Call node points to first actual in list + + Set_First_Named_Actual (N, Explicit_Actual_Parameter (A)); + + else + Set_Next_Named_Actual (Last, Explicit_Actual_Parameter (A)); + end if; + + Last := A; + Set_Next_Named_Actual (Last, Empty); + end Chain; + + --------------- + -- Reporting -- + --------------- + + function Reporting return Boolean is + begin + if not Report then + return False; + + elsif not Within_Init_Proc then + return True; + + elsif Is_Init_Proc (Entity (Name (N))) then + return False; + + else + return True; + end if; + end Reporting; + + -- Start of processing for Normalize_Actuals + + begin + if Is_Access_Type (S) then + + -- The name in the call is a function call that returns an access + -- to subprogram. The designated type has the list of formals. + + Formal := First_Formal (Designated_Type (S)); + else + Formal := First_Formal (S); + end if; + + while Present (Formal) loop + Formals_To_Match := Formals_To_Match + 1; + Next_Formal (Formal); + end loop; + + -- Find if there is a named association, and verify that no positional + -- associations appear after named ones. + + if Present (Actuals) then + Actual := First (Actuals); + end if; + + while Present (Actual) + and then Nkind (Actual) /= N_Parameter_Association + loop + Actuals_To_Match := Actuals_To_Match + 1; + Next (Actual); + end loop; + + if No (Actual) and Actuals_To_Match = Formals_To_Match then + + -- Most common case: positional notation, no defaults + + Success := True; + return; + + elsif Actuals_To_Match > Formals_To_Match then + + -- Too many actuals: will not work + + if Reporting then + if Is_Entity_Name (Name (N)) then + Error_Msg_N ("too many arguments in call to&", Name (N)); + else + Error_Msg_N ("too many arguments in call", N); + end if; + end if; + + Success := False; + return; + end if; + + First_Named := Actual; + + while Present (Actual) loop + if Nkind (Actual) /= N_Parameter_Association then + Error_Msg_N + ("positional parameters not allowed after named ones", Actual); + Success := False; + return; + + else + Actuals_To_Match := Actuals_To_Match + 1; + end if; + + Next (Actual); + end loop; + + if Present (Actuals) then + Actual := First (Actuals); + end if; + + Formal := First_Formal (S); + while Present (Formal) loop + + -- Match the formals in order. If the corresponding actual + -- is positional, nothing to do. Else scan the list of named + -- actuals to find the one with the right name. + + if Present (Actual) + and then Nkind (Actual) /= N_Parameter_Association + then + Next (Actual); + Actuals_To_Match := Actuals_To_Match - 1; + Formals_To_Match := Formals_To_Match - 1; + + else + -- For named parameters, search the list of actuals to find + -- one that matches the next formal name. + + Actual := First_Named; + Found := False; + + while Present (Actual) loop + if Chars (Selector_Name (Actual)) = Chars (Formal) then + Found := True; + Chain (Actual); + Actuals_To_Match := Actuals_To_Match - 1; + Formals_To_Match := Formals_To_Match - 1; + exit; + end if; + + Next (Actual); + end loop; + + if not Found then + if Ekind (Formal) /= E_In_Parameter + or else No (Default_Value (Formal)) + then + if Reporting then + if (Comes_From_Source (S) + or else Sloc (S) = Standard_Location) + and then Is_Overloadable (S) + then + if No (Actuals) + and then + (Nkind (Parent (N)) = N_Procedure_Call_Statement + or else + (Nkind (Parent (N)) = N_Function_Call + or else + Nkind (Parent (N)) = N_Parameter_Association)) + and then Ekind (S) /= E_Function + then + Set_Etype (N, Etype (S)); + else + Error_Msg_Name_1 := Chars (S); + Error_Msg_Sloc := Sloc (S); + Error_Msg_NE + ("missing argument for parameter & " & + "in call to % declared #", N, Formal); + end if; + + elsif Is_Overloadable (S) then + Error_Msg_Name_1 := Chars (S); + + -- Point to type derivation that generated the + -- operation. + + Error_Msg_Sloc := Sloc (Parent (S)); + + Error_Msg_NE + ("missing argument for parameter & " & + "in call to % (inherited) #", N, Formal); + + else + Error_Msg_NE + ("missing argument for parameter &", N, Formal); + end if; + end if; + + Success := False; + return; + + else + Formals_To_Match := Formals_To_Match - 1; + end if; + end if; + end if; + + Next_Formal (Formal); + end loop; + + if Formals_To_Match = 0 and then Actuals_To_Match = 0 then + Success := True; + return; + + else + if Reporting then + + -- Find some superfluous named actual that did not get + -- attached to the list of associations. + + Actual := First (Actuals); + + while Present (Actual) loop + if Nkind (Actual) = N_Parameter_Association + and then Actual /= Last + and then No (Next_Named_Actual (Actual)) + then + Error_Msg_N ("unmatched actual & in call", + Selector_Name (Actual)); + exit; + end if; + + Next (Actual); + end loop; + end if; + + Success := False; + return; + end if; + end Normalize_Actuals; + + -------------------------------- + -- Note_Possible_Modification -- + -------------------------------- + + procedure Note_Possible_Modification (N : Node_Id) is + Modification_Comes_From_Source : constant Boolean := + Comes_From_Source (Parent (N)); + + Ent : Entity_Id; + Exp : Node_Id; + + begin + -- Loop to find referenced entity, if there is one + + Exp := N; + loop + <<Continue>> + Ent := Empty; + + if Is_Entity_Name (Exp) then + Ent := Entity (Exp); + + -- If the entity is missing, it is an undeclared identifier, + -- and there is nothing to annotate. + + if No (Ent) then + return; + end if; + + elsif Nkind (Exp) = N_Explicit_Dereference then + declare + P : constant Node_Id := Prefix (Exp); + + begin + if Nkind (P) = N_Selected_Component + and then Present ( + Entry_Formal (Entity (Selector_Name (P)))) + then + -- Case of a reference to an entry formal + + Ent := Entry_Formal (Entity (Selector_Name (P))); + + elsif Nkind (P) = N_Identifier + and then Nkind (Parent (Entity (P))) = N_Object_Declaration + and then Present (Expression (Parent (Entity (P)))) + and then Nkind (Expression (Parent (Entity (P)))) + = N_Reference + then + -- Case of a reference to a value on which + -- side effects have been removed. + + Exp := Prefix (Expression (Parent (Entity (P)))); + goto Continue; + + else + return; + + end if; + end; + + elsif Nkind (Exp) = N_Type_Conversion + or else Nkind (Exp) = N_Unchecked_Type_Conversion + then + Exp := Expression (Exp); + goto Continue; + + elsif Nkind (Exp) = N_Slice + or else Nkind (Exp) = N_Indexed_Component + or else Nkind (Exp) = N_Selected_Component + then + Exp := Prefix (Exp); + goto Continue; + + else + return; + end if; + + -- Now look for entity being referenced + + if Present (Ent) then + if Is_Object (Ent) then + if Comes_From_Source (Exp) + or else Modification_Comes_From_Source + then + Set_Never_Set_In_Source (Ent, False); + end if; + + Set_Is_True_Constant (Ent, False); + Set_Current_Value (Ent, Empty); + Set_Is_Known_Null (Ent, False); + + if not Can_Never_Be_Null (Ent) then + Set_Is_Known_Non_Null (Ent, False); + end if; + + -- Follow renaming chain + + if (Ekind (Ent) = E_Variable or else Ekind (Ent) = E_Constant) + and then Present (Renamed_Object (Ent)) + then + Exp := Renamed_Object (Ent); + goto Continue; + end if; + + -- Generate a reference only if the assignment comes from + -- source. This excludes, for example, calls to a dispatching + -- assignment operation when the left-hand side is tagged. + + if Modification_Comes_From_Source then + Generate_Reference (Ent, Exp, 'm'); + end if; + end if; + + Kill_Checks (Ent); + return; + end if; + end loop; + end Note_Possible_Modification; + + ------------------------- + -- Object_Access_Level -- + ------------------------- + + function Object_Access_Level (Obj : Node_Id) return Uint is + E : Entity_Id; + + -- Returns the static accessibility level of the view denoted + -- by Obj. Note that the value returned is the result of a + -- call to Scope_Depth. Only scope depths associated with + -- dynamic scopes can actually be returned. Since only + -- relative levels matter for accessibility checking, the fact + -- that the distance between successive levels of accessibility + -- is not always one is immaterial (invariant: if level(E2) is + -- deeper than level(E1), then Scope_Depth(E1) < Scope_Depth(E2)). + + begin + if Is_Entity_Name (Obj) then + E := Entity (Obj); + + -- If E is a type then it denotes a current instance. + -- For this case we add one to the normal accessibility + -- level of the type to ensure that current instances + -- are treated as always being deeper than than the level + -- of any visible named access type (see 3.10.2(21)). + + if Is_Type (E) then + return Type_Access_Level (E) + 1; + + elsif Present (Renamed_Object (E)) then + return Object_Access_Level (Renamed_Object (E)); + + -- Similarly, if E is a component of the current instance of a + -- protected type, any instance of it is assumed to be at a deeper + -- level than the type. For a protected object (whose type is an + -- anonymous protected type) its components are at the same level + -- as the type itself. + + elsif not Is_Overloadable (E) + and then Ekind (Scope (E)) = E_Protected_Type + and then Comes_From_Source (Scope (E)) + then + return Type_Access_Level (Scope (E)) + 1; + + else + return Scope_Depth (Enclosing_Dynamic_Scope (E)); + end if; + + elsif Nkind (Obj) = N_Selected_Component then + if Is_Access_Type (Etype (Prefix (Obj))) then + return Type_Access_Level (Etype (Prefix (Obj))); + else + return Object_Access_Level (Prefix (Obj)); + end if; + + elsif Nkind (Obj) = N_Indexed_Component then + if Is_Access_Type (Etype (Prefix (Obj))) then + return Type_Access_Level (Etype (Prefix (Obj))); + else + return Object_Access_Level (Prefix (Obj)); + end if; + + elsif Nkind (Obj) = N_Explicit_Dereference then + + -- If the prefix is a selected access discriminant then + -- we make a recursive call on the prefix, which will + -- in turn check the level of the prefix object of + -- the selected discriminant. + + if Nkind (Prefix (Obj)) = N_Selected_Component + and then Ekind (Etype (Prefix (Obj))) = E_Anonymous_Access_Type + and then + Ekind (Entity (Selector_Name (Prefix (Obj)))) = E_Discriminant + then + return Object_Access_Level (Prefix (Obj)); + else + return Type_Access_Level (Etype (Prefix (Obj))); + end if; + + elsif Nkind (Obj) = N_Type_Conversion + or else Nkind (Obj) = N_Unchecked_Type_Conversion + then + return Object_Access_Level (Expression (Obj)); + + -- Function results are objects, so we get either the access level + -- of the function or, in the case of an indirect call, the level of + -- of the access-to-subprogram type. + + elsif Nkind (Obj) = N_Function_Call then + if Is_Entity_Name (Name (Obj)) then + return Subprogram_Access_Level (Entity (Name (Obj))); + else + return Type_Access_Level (Etype (Prefix (Name (Obj)))); + end if; + + -- For convenience we handle qualified expressions, even though + -- they aren't technically object names. + + elsif Nkind (Obj) = N_Qualified_Expression then + return Object_Access_Level (Expression (Obj)); + + -- Otherwise return the scope level of Standard. + -- (If there are cases that fall through + -- to this point they will be treated as + -- having global accessibility for now. ???) + + else + return Scope_Depth (Standard_Standard); + end if; + end Object_Access_Level; + + ----------------------- + -- Private_Component -- + ----------------------- + + function Private_Component (Type_Id : Entity_Id) return Entity_Id is + Ancestor : constant Entity_Id := Base_Type (Type_Id); + + function Trace_Components + (T : Entity_Id; + Check : Boolean) return Entity_Id; + -- Recursive function that does the work, and checks against circular + -- definition for each subcomponent type. + + ---------------------- + -- Trace_Components -- + ---------------------- + + function Trace_Components + (T : Entity_Id; + Check : Boolean) return Entity_Id + is + Btype : constant Entity_Id := Base_Type (T); + Component : Entity_Id; + P : Entity_Id; + Candidate : Entity_Id := Empty; + + begin + if Check and then Btype = Ancestor then + Error_Msg_N ("circular type definition", Type_Id); + return Any_Type; + end if; + + if Is_Private_Type (Btype) + and then not Is_Generic_Type (Btype) + then + if Present (Full_View (Btype)) + and then Is_Record_Type (Full_View (Btype)) + and then not Is_Frozen (Btype) + then + -- To indicate that the ancestor depends on a private type, + -- the current Btype is sufficient. However, to check for + -- circular definition we must recurse on the full view. + + Candidate := Trace_Components (Full_View (Btype), True); + + if Candidate = Any_Type then + return Any_Type; + else + return Btype; + end if; + + else + return Btype; + end if; + + elsif Is_Array_Type (Btype) then + return Trace_Components (Component_Type (Btype), True); + + elsif Is_Record_Type (Btype) then + Component := First_Entity (Btype); + while Present (Component) loop + + -- Skip anonymous types generated by constrained components + + if not Is_Type (Component) then + P := Trace_Components (Etype (Component), True); + + if Present (P) then + if P = Any_Type then + return P; + else + Candidate := P; + end if; + end if; + end if; + + Next_Entity (Component); + end loop; + + return Candidate; + + else + return Empty; + end if; + end Trace_Components; + + -- Start of processing for Private_Component + + begin + return Trace_Components (Type_Id, False); + end Private_Component; + + ----------------------- + -- Process_End_Label -- + ----------------------- + + procedure Process_End_Label + (N : Node_Id; + Typ : Character; + Ent : Entity_Id) + is + Loc : Source_Ptr; + Nam : Node_Id; + + Label_Ref : Boolean; + -- Set True if reference to end label itself is required + + Endl : Node_Id; + -- Gets set to the operator symbol or identifier that references + -- the entity Ent. For the child unit case, this is the identifier + -- from the designator. For other cases, this is simply Endl. + + procedure Generate_Parent_Ref (N : Node_Id); + -- N is an identifier node that appears as a parent unit reference + -- in the case where Ent is a child unit. This procedure generates + -- an appropriate cross-reference entry. + + ------------------------- + -- Generate_Parent_Ref -- + ------------------------- + + procedure Generate_Parent_Ref (N : Node_Id) is + Parent_Ent : Entity_Id; + + begin + -- Search up scope stack. The reason we do this is that normal + -- visibility analysis would not work for two reasons. First in + -- some subunit cases, the entry for the parent unit may not be + -- visible, and in any case there can be a local entity that + -- hides the scope entity. + + Parent_Ent := Current_Scope; + while Present (Parent_Ent) loop + if Chars (Parent_Ent) = Chars (N) then + + -- Generate the reference. We do NOT consider this as a + -- reference for unreferenced symbol purposes, but we do + -- force a cross-reference even if the end line does not + -- come from source (the caller already generated the + -- appropriate Typ for this situation). + + Generate_Reference + (Parent_Ent, N, 'r', Set_Ref => False, Force => True); + Style.Check_Identifier (N, Parent_Ent); + return; + end if; + + Parent_Ent := Scope (Parent_Ent); + end loop; + + -- Fall through means entity was not found -- that's odd, but + -- the appropriate thing is simply to ignore and not generate + -- any cross-reference for this entry. + + return; + end Generate_Parent_Ref; + + -- Start of processing for Process_End_Label + + begin + -- If no node, ignore. This happens in some error situations, + -- and also for some internally generated structures where no + -- end label references are required in any case. + + if No (N) then + return; + end if; + + -- Nothing to do if no End_Label, happens for internally generated + -- constructs where we don't want an end label reference anyway. + -- Also nothing to do if Endl is a string literal, which means + -- there was some prior error (bad operator symbol) + + Endl := End_Label (N); + + if No (Endl) or else Nkind (Endl) = N_String_Literal then + return; + end if; + + -- Reference node is not in extended main source unit + + if not In_Extended_Main_Source_Unit (N) then + + -- Generally we do not collect references except for the + -- extended main source unit. The one exception is the 'e' + -- entry for a package spec, where it is useful for a client + -- to have the ending information to define scopes. + + if Typ /= 'e' then + return; + + else + Label_Ref := False; + + -- For this case, we can ignore any parent references, + -- but we need the package name itself for the 'e' entry. + + if Nkind (Endl) = N_Designator then + Endl := Identifier (Endl); + end if; + end if; + + -- Reference is in extended main source unit + + else + Label_Ref := True; + + -- For designator, generate references for the parent entries + + if Nkind (Endl) = N_Designator then + + -- Generate references for the prefix if the END line comes + -- from source (otherwise we do not need these references) + + if Comes_From_Source (Endl) then + Nam := Name (Endl); + while Nkind (Nam) = N_Selected_Component loop + Generate_Parent_Ref (Selector_Name (Nam)); + Nam := Prefix (Nam); + end loop; + + Generate_Parent_Ref (Nam); + end if; + + Endl := Identifier (Endl); + end if; + end if; + + -- If the end label is not for the given entity, then either we have + -- some previous error, or this is a generic instantiation for which + -- we do not need to make a cross-reference in this case anyway. In + -- either case we simply ignore the call. + + if Chars (Ent) /= Chars (Endl) then + return; + end if; + + -- If label was really there, then generate a normal reference + -- and then adjust the location in the end label to point past + -- the name (which should almost always be the semicolon). + + Loc := Sloc (Endl); + + if Comes_From_Source (Endl) then + + -- If a label reference is required, then do the style check + -- and generate an l-type cross-reference entry for the label + + if Label_Ref then + if Style_Check then + Style.Check_Identifier (Endl, Ent); + end if; + Generate_Reference (Ent, Endl, 'l', Set_Ref => False); + end if; + + -- Set the location to point past the label (normally this will + -- mean the semicolon immediately following the label). This is + -- done for the sake of the 'e' or 't' entry generated below. + + Get_Decoded_Name_String (Chars (Endl)); + Set_Sloc (Endl, Sloc (Endl) + Source_Ptr (Name_Len)); + end if; + + -- Now generate the e/t reference + + Generate_Reference (Ent, Endl, Typ, Set_Ref => False, Force => True); + + -- Restore Sloc, in case modified above, since we have an identifier + -- and the normal Sloc should be left set in the tree. + + Set_Sloc (Endl, Loc); + end Process_End_Label; + + ------------------ + -- Real_Convert -- + ------------------ + + -- We do the conversion to get the value of the real string by using + -- the scanner, see Sinput for details on use of the internal source + -- buffer for scanning internal strings. + + function Real_Convert (S : String) return Node_Id is + Save_Src : constant Source_Buffer_Ptr := Source; + Negative : Boolean; + + begin + Source := Internal_Source_Ptr; + Scan_Ptr := 1; + + for J in S'Range loop + Source (Source_Ptr (J)) := S (J); + end loop; + + Source (S'Length + 1) := EOF; + + if Source (Scan_Ptr) = '-' then + Negative := True; + Scan_Ptr := Scan_Ptr + 1; + else + Negative := False; + end if; + + Scan; + + if Negative then + Set_Realval (Token_Node, UR_Negate (Realval (Token_Node))); + end if; + + Source := Save_Src; + return Token_Node; + end Real_Convert; + + --------------------- + -- Rep_To_Pos_Flag -- + --------------------- + + function Rep_To_Pos_Flag (E : Entity_Id; Loc : Source_Ptr) return Node_Id is + begin + return New_Occurrence_Of + (Boolean_Literals (not Range_Checks_Suppressed (E)), Loc); + end Rep_To_Pos_Flag; + + -------------------- + -- Require_Entity -- + -------------------- + + procedure Require_Entity (N : Node_Id) is + begin + if Is_Entity_Name (N) and then No (Entity (N)) then + if Total_Errors_Detected /= 0 then + Set_Entity (N, Any_Id); + else + raise Program_Error; + end if; + end if; + end Require_Entity; + + ------------------------------ + -- Requires_Transient_Scope -- + ------------------------------ + + -- A transient scope is required when variable-sized temporaries are + -- allocated in the primary or secondary stack, or when finalization + -- actions must be generated before the next instruction. + + function Requires_Transient_Scope (Id : Entity_Id) return Boolean is + Typ : constant Entity_Id := Underlying_Type (Id); + + -- Start of processing for Requires_Transient_Scope + + begin + -- This is a private type which is not completed yet. This can only + -- happen in a default expression (of a formal parameter or of a + -- record component). Do not expand transient scope in this case + + if No (Typ) then + return False; + + -- Do not expand transient scope for non-existent procedure return + + elsif Typ = Standard_Void_Type then + return False; + + -- Elementary types do not require a transient scope + + elsif Is_Elementary_Type (Typ) then + return False; + + -- Generally, indefinite subtypes require a transient scope, since the + -- back end cannot generate temporaries, since this is not a valid type + -- for declaring an object. It might be possible to relax this in the + -- future, e.g. by declaring the maximum possible space for the type. + + elsif Is_Indefinite_Subtype (Typ) then + return True; + + -- Functions returning tagged types may dispatch on result so their + -- returned value is allocated on the secondary stack. Controlled + -- type temporaries need finalization. + + elsif Is_Tagged_Type (Typ) + or else Has_Controlled_Component (Typ) + then + return True; + + -- Record type + + elsif Is_Record_Type (Typ) then + + -- In GCC 2, discriminated records always require a transient + -- scope because the back end otherwise tries to allocate a + -- variable length temporary for the particular variant. + + if Opt.GCC_Version = 2 + and then Has_Discriminants (Typ) + then + return True; + + -- For GCC 3, or for a non-discriminated record in GCC 2, we are + -- OK if none of the component types requires a transient scope. + -- Note that we already know that this is a definite type (i.e. + -- has discriminant defaults if it is a discriminated record). + + else + declare + Comp : Entity_Id; + begin + Comp := First_Entity (Typ); + while Present (Comp) loop + if Ekind (Comp) = E_Component + and then Requires_Transient_Scope (Etype (Comp)) + then + return True; + else + Next_Entity (Comp); + end if; + end loop; + end; + + return False; + end if; + + -- String literal types never require transient scope + + elsif Ekind (Typ) = E_String_Literal_Subtype then + return False; + + -- Array type. Note that we already know that this is a constrained + -- array, since unconstrained arrays will fail the indefinite test. + + elsif Is_Array_Type (Typ) then + + -- If component type requires a transient scope, the array does too + + if Requires_Transient_Scope (Component_Type (Typ)) then + return True; + + -- Otherwise, we only need a transient scope if the size is not + -- known at compile time. + + else + return not Size_Known_At_Compile_Time (Typ); + end if; + + -- All other cases do not require a transient scope + + else + return False; + end if; + end Requires_Transient_Scope; + + -------------------------- + -- Reset_Analyzed_Flags -- + -------------------------- + + procedure Reset_Analyzed_Flags (N : Node_Id) is + + function Clear_Analyzed + (N : Node_Id) return Traverse_Result; + -- Function used to reset Analyzed flags in tree. Note that we do + -- not reset Analyzed flags in entities, since there is no need to + -- renalalyze entities, and indeed, it is wrong to do so, since it + -- can result in generating auxiliary stuff more than once. + + -------------------- + -- Clear_Analyzed -- + -------------------- + + function Clear_Analyzed + (N : Node_Id) return Traverse_Result + is + begin + if not Has_Extension (N) then + Set_Analyzed (N, False); + end if; + + return OK; + end Clear_Analyzed; + + function Reset_Analyzed is + new Traverse_Func (Clear_Analyzed); + + Discard : Traverse_Result; + pragma Warnings (Off, Discard); + + -- Start of processing for Reset_Analyzed_Flags + + begin + Discard := Reset_Analyzed (N); + end Reset_Analyzed_Flags; + + --------------------------- + -- Safe_To_Capture_Value -- + --------------------------- + + function Safe_To_Capture_Value + (N : Node_Id; + Ent : Entity_Id) return Boolean + is + begin + -- The only entities for which we track constant values are variables, + -- out parameters and in out parameters, so check if we have this case. + + if Ekind (Ent) /= E_Variable + and then + Ekind (Ent) /= E_Out_Parameter + and then + Ekind (Ent) /= E_In_Out_Parameter + then + return False; + end if; + + -- Skip volatile and aliased variables, since funny things might + -- be going on in these cases which we cannot necessarily track. + -- Also skip any variable for which an address clause is given. + + -- Should we have a flag Has_Address_Clause ??? + + if Treat_As_Volatile (Ent) + or else Is_Aliased (Ent) + or else Present (Address_Clause (Ent)) + then + return False; + end if; + + -- OK, all above conditions are met. We also require that the scope + -- of the reference be the same as the scope of the entity, not + -- counting packages and blocks. + + declare + E_Scope : constant Entity_Id := Scope (Ent); + R_Scope : Entity_Id; + + begin + R_Scope := Current_Scope; + while R_Scope /= Standard_Standard loop + exit when R_Scope = E_Scope; + + if Ekind (R_Scope) /= E_Package + and then + Ekind (R_Scope) /= E_Block + then + return False; + else + R_Scope := Scope (R_Scope); + end if; + end loop; + end; + + -- We also require that the reference does not appear in a context + -- where it is not sure to be executed (i.e. a conditional context + -- or an exception handler). + + declare + Desc : Node_Id; + P : Node_Id; + + begin + Desc := N; + P := Parent (N); + while Present (P) loop + if Nkind (P) = N_If_Statement + or else Nkind (P) = N_Case_Statement + or else (Nkind (P) = N_And_Then and then Desc = Right_Opnd (P)) + or else (Nkind (P) = N_Or_Else and then Desc = Right_Opnd (P)) + or else Nkind (P) = N_Exception_Handler + or else Nkind (P) = N_Selective_Accept + or else Nkind (P) = N_Conditional_Entry_Call + or else Nkind (P) = N_Timed_Entry_Call + or else Nkind (P) = N_Asynchronous_Select + then + return False; + else + Desc := P; + P := Parent (P); + end if; + end loop; + end; + + -- OK, looks safe to set value + + return True; + end Safe_To_Capture_Value; + + --------------- + -- Same_Name -- + --------------- + + function Same_Name (N1, N2 : Node_Id) return Boolean is + K1 : constant Node_Kind := Nkind (N1); + K2 : constant Node_Kind := Nkind (N2); + + begin + if (K1 = N_Identifier or else K1 = N_Defining_Identifier) + and then (K2 = N_Identifier or else K2 = N_Defining_Identifier) + then + return Chars (N1) = Chars (N2); + + elsif (K1 = N_Selected_Component or else K1 = N_Expanded_Name) + and then (K2 = N_Selected_Component or else K2 = N_Expanded_Name) + then + return Same_Name (Selector_Name (N1), Selector_Name (N2)) + and then Same_Name (Prefix (N1), Prefix (N2)); + + else + return False; + end if; + end Same_Name; + + --------------- + -- Same_Type -- + --------------- + + function Same_Type (T1, T2 : Entity_Id) return Boolean is + begin + if T1 = T2 then + return True; + + elsif not Is_Constrained (T1) + and then not Is_Constrained (T2) + and then Base_Type (T1) = Base_Type (T2) + then + return True; + + -- For now don't bother with case of identical constraints, to be + -- fiddled with later on perhaps (this is only used for optimization + -- purposes, so it is not critical to do a best possible job) + + else + return False; + end if; + end Same_Type; + + ------------------------ + -- Scope_Is_Transient -- + ------------------------ + + function Scope_Is_Transient return Boolean is + begin + return Scope_Stack.Table (Scope_Stack.Last).Is_Transient; + end Scope_Is_Transient; + + ------------------ + -- Scope_Within -- + ------------------ + + function Scope_Within (Scope1, Scope2 : Entity_Id) return Boolean is + Scop : Entity_Id; + + begin + Scop := Scope1; + while Scop /= Standard_Standard loop + Scop := Scope (Scop); + + if Scop = Scope2 then + return True; + end if; + end loop; + + return False; + end Scope_Within; + + -------------------------- + -- Scope_Within_Or_Same -- + -------------------------- + + function Scope_Within_Or_Same (Scope1, Scope2 : Entity_Id) return Boolean is + Scop : Entity_Id; + + begin + Scop := Scope1; + while Scop /= Standard_Standard loop + if Scop = Scope2 then + return True; + else + Scop := Scope (Scop); + end if; + end loop; + + return False; + end Scope_Within_Or_Same; + + ------------------------ + -- Set_Current_Entity -- + ------------------------ + + -- The given entity is to be set as the currently visible definition + -- of its associated name (i.e. the Node_Id associated with its name). + -- All we have to do is to get the name from the identifier, and + -- then set the associated Node_Id to point to the given entity. + + procedure Set_Current_Entity (E : Entity_Id) is + begin + Set_Name_Entity_Id (Chars (E), E); + end Set_Current_Entity; + + --------------------------------- + -- Set_Entity_With_Style_Check -- + --------------------------------- + + procedure Set_Entity_With_Style_Check (N : Node_Id; Val : Entity_Id) is + Val_Actual : Entity_Id; + Nod : Node_Id; + + begin + Set_Entity (N, Val); + + if Style_Check + and then not Suppress_Style_Checks (Val) + and then not In_Instance + then + if Nkind (N) = N_Identifier then + Nod := N; + + elsif Nkind (N) = N_Expanded_Name then + Nod := Selector_Name (N); + + else + return; + end if; + + -- A special situation arises for derived operations, where we want + -- to do the check against the parent (since the Sloc of the derived + -- operation points to the derived type declaration itself). + + Val_Actual := Val; + while not Comes_From_Source (Val_Actual) + and then Nkind (Val_Actual) in N_Entity + and then (Ekind (Val_Actual) = E_Enumeration_Literal + or else Is_Subprogram (Val_Actual) + or else Is_Generic_Subprogram (Val_Actual)) + and then Present (Alias (Val_Actual)) + loop + Val_Actual := Alias (Val_Actual); + end loop; + + -- Renaming declarations for generic actuals do not come from source, + -- and have a different name from that of the entity they rename, so + -- there is no style check to perform here. + + if Chars (Nod) = Chars (Val_Actual) then + Style.Check_Identifier (Nod, Val_Actual); + end if; + end if; + + Set_Entity (N, Val); + end Set_Entity_With_Style_Check; + + ------------------------ + -- Set_Name_Entity_Id -- + ------------------------ + + procedure Set_Name_Entity_Id (Id : Name_Id; Val : Entity_Id) is + begin + Set_Name_Table_Info (Id, Int (Val)); + end Set_Name_Entity_Id; + + --------------------- + -- Set_Next_Actual -- + --------------------- + + procedure Set_Next_Actual (Ass1_Id : Node_Id; Ass2_Id : Node_Id) is + begin + if Nkind (Parent (Ass1_Id)) = N_Parameter_Association then + Set_First_Named_Actual (Parent (Ass1_Id), Ass2_Id); + end if; + end Set_Next_Actual; + + ----------------------- + -- Set_Public_Status -- + ----------------------- + + procedure Set_Public_Status (Id : Entity_Id) is + S : constant Entity_Id := Current_Scope; + + begin + -- Everything in the scope of Standard is public + + if S = Standard_Standard then + Set_Is_Public (Id); + + -- Entity is definitely not public if enclosing scope is not public + + elsif not Is_Public (S) then + return; + + -- An object declaration that occurs in a handled sequence of statements + -- is the declaration for a temporary object generated by the expander. + -- It never needs to be made public and furthermore, making it public + -- can cause back end problems if it is of variable size. + + elsif Nkind (Parent (Id)) = N_Object_Declaration + and then + Nkind (Parent (Parent (Id))) = N_Handled_Sequence_Of_Statements + then + return; + + -- Entities in public packages or records are public + + elsif Ekind (S) = E_Package or Is_Record_Type (S) then + Set_Is_Public (Id); + + -- The bounds of an entry family declaration can generate object + -- declarations that are visible to the back-end, e.g. in the + -- the declaration of a composite type that contains tasks. + + elsif Is_Concurrent_Type (S) + and then not Has_Completion (S) + and then Nkind (Parent (Id)) = N_Object_Declaration + then + Set_Is_Public (Id); + end if; + end Set_Public_Status; + + ---------------------------- + -- Set_Scope_Is_Transient -- + ---------------------------- + + procedure Set_Scope_Is_Transient (V : Boolean := True) is + begin + Scope_Stack.Table (Scope_Stack.Last).Is_Transient := V; + end Set_Scope_Is_Transient; + + ------------------- + -- Set_Size_Info -- + ------------------- + + procedure Set_Size_Info (T1, T2 : Entity_Id) is + begin + -- We copy Esize, but not RM_Size, since in general RM_Size is + -- subtype specific and does not get inherited by all subtypes. + + Set_Esize (T1, Esize (T2)); + Set_Has_Biased_Representation (T1, Has_Biased_Representation (T2)); + + if Is_Discrete_Or_Fixed_Point_Type (T1) + and then + Is_Discrete_Or_Fixed_Point_Type (T2) + then + Set_Is_Unsigned_Type (T1, Is_Unsigned_Type (T2)); + end if; + Set_Alignment (T1, Alignment (T2)); + end Set_Size_Info; + + -------------------- + -- Static_Integer -- + -------------------- + + function Static_Integer (N : Node_Id) return Uint is + begin + Analyze_And_Resolve (N, Any_Integer); + + if N = Error + or else Error_Posted (N) + or else Etype (N) = Any_Type + then + return No_Uint; + end if; + + if Is_Static_Expression (N) then + if not Raises_Constraint_Error (N) then + return Expr_Value (N); + else + return No_Uint; + end if; + + elsif Etype (N) = Any_Type then + return No_Uint; + + else + Flag_Non_Static_Expr + ("static integer expression required here", N); + return No_Uint; + end if; + end Static_Integer; + + -------------------------- + -- Statically_Different -- + -------------------------- + + function Statically_Different (E1, E2 : Node_Id) return Boolean is + R1 : constant Node_Id := Get_Referenced_Object (E1); + R2 : constant Node_Id := Get_Referenced_Object (E2); + begin + return Is_Entity_Name (R1) + and then Is_Entity_Name (R2) + and then Entity (R1) /= Entity (R2) + and then not Is_Formal (Entity (R1)) + and then not Is_Formal (Entity (R2)); + end Statically_Different; + + ----------------------------- + -- Subprogram_Access_Level -- + ----------------------------- + + function Subprogram_Access_Level (Subp : Entity_Id) return Uint is + begin + if Present (Alias (Subp)) then + return Subprogram_Access_Level (Alias (Subp)); + else + return Scope_Depth (Enclosing_Dynamic_Scope (Subp)); + end if; + end Subprogram_Access_Level; + + ----------------- + -- Trace_Scope -- + ----------------- + + procedure Trace_Scope (N : Node_Id; E : Entity_Id; Msg : String) is + begin + if Debug_Flag_W then + for J in 0 .. Scope_Stack.Last loop + Write_Str (" "); + end loop; + + Write_Str (Msg); + Write_Name (Chars (E)); + Write_Str (" line "); + Write_Int (Int (Get_Logical_Line_Number (Sloc (N)))); + Write_Eol; + end if; + end Trace_Scope; + + ----------------------- + -- Transfer_Entities -- + ----------------------- + + procedure Transfer_Entities (From : Entity_Id; To : Entity_Id) is + Ent : Entity_Id := First_Entity (From); + + begin + if No (Ent) then + return; + end if; + + if (Last_Entity (To)) = Empty then + Set_First_Entity (To, Ent); + else + Set_Next_Entity (Last_Entity (To), Ent); + end if; + + Set_Last_Entity (To, Last_Entity (From)); + + while Present (Ent) loop + Set_Scope (Ent, To); + + if not Is_Public (Ent) then + Set_Public_Status (Ent); + + if Is_Public (Ent) + and then Ekind (Ent) = E_Record_Subtype + + then + -- The components of the propagated Itype must be public + -- as well. + + declare + Comp : Entity_Id; + + begin + Comp := First_Entity (Ent); + while Present (Comp) loop + Set_Is_Public (Comp); + Next_Entity (Comp); + end loop; + end; + end if; + end if; + + Next_Entity (Ent); + end loop; + + Set_First_Entity (From, Empty); + Set_Last_Entity (From, Empty); + end Transfer_Entities; + + ----------------------- + -- Type_Access_Level -- + ----------------------- + + function Type_Access_Level (Typ : Entity_Id) return Uint is + Btyp : Entity_Id; + + begin + -- If the type is an anonymous access type we treat it as being + -- declared at the library level to ensure that names such as + -- X.all'access don't fail static accessibility checks. + + -- Ada 2005 (AI-230): In case of anonymous access types that are + -- component_definition or discriminants of a nonlimited type, + -- the level is the same as that of the enclosing component type. + + Btyp := Base_Type (Typ); + + if Ekind (Btyp) in Access_Kind then + if Ekind (Btyp) = E_Anonymous_Access_Type + and then not Is_Local_Anonymous_Access (Typ) -- Ada 2005 (AI-230) + then + return Scope_Depth (Standard_Standard); + end if; + + Btyp := Root_Type (Btyp); + + -- The accessibility level of anonymous acccess types associated with + -- discriminants is that of the current instance of the type, and + -- that's deeper than the type itself (AARM 3.10.2 (12.3.21)). + + if Ekind (Typ) = E_Anonymous_Access_Type + and then Present (Associated_Node_For_Itype (Typ)) + and then Nkind (Associated_Node_For_Itype (Typ)) = + N_Discriminant_Specification + then + return Scope_Depth (Enclosing_Dynamic_Scope (Btyp)) + 1; + end if; + end if; + + return Scope_Depth (Enclosing_Dynamic_Scope (Btyp)); + end Type_Access_Level; + + -------------------------- + -- Unit_Declaration_Node -- + -------------------------- + + function Unit_Declaration_Node (Unit_Id : Entity_Id) return Node_Id is + N : Node_Id := Parent (Unit_Id); + + begin + -- Predefined operators do not have a full function declaration + + if Ekind (Unit_Id) = E_Operator then + return N; + end if; + + while Nkind (N) /= N_Abstract_Subprogram_Declaration + and then Nkind (N) /= N_Formal_Package_Declaration + and then Nkind (N) /= N_Function_Instantiation + and then Nkind (N) /= N_Generic_Package_Declaration + and then Nkind (N) /= N_Generic_Subprogram_Declaration + and then Nkind (N) /= N_Package_Declaration + and then Nkind (N) /= N_Package_Body + and then Nkind (N) /= N_Package_Instantiation + and then Nkind (N) /= N_Package_Renaming_Declaration + and then Nkind (N) /= N_Procedure_Instantiation + and then Nkind (N) /= N_Protected_Body + and then Nkind (N) /= N_Subprogram_Declaration + and then Nkind (N) /= N_Subprogram_Body + and then Nkind (N) /= N_Subprogram_Body_Stub + and then Nkind (N) /= N_Subprogram_Renaming_Declaration + and then Nkind (N) /= N_Task_Body + and then Nkind (N) /= N_Task_Type_Declaration + and then Nkind (N) not in N_Formal_Subprogram_Declaration + and then Nkind (N) not in N_Generic_Renaming_Declaration + loop + N := Parent (N); + pragma Assert (Present (N)); + end loop; + + return N; + end Unit_Declaration_Node; + + ------------------------------ + -- Universal_Interpretation -- + ------------------------------ + + function Universal_Interpretation (Opnd : Node_Id) return Entity_Id is + Index : Interp_Index; + It : Interp; + + begin + -- The argument may be a formal parameter of an operator or subprogram + -- with multiple interpretations, or else an expression for an actual. + + if Nkind (Opnd) = N_Defining_Identifier + or else not Is_Overloaded (Opnd) + then + if Etype (Opnd) = Universal_Integer + or else Etype (Opnd) = Universal_Real + then + return Etype (Opnd); + else + return Empty; + end if; + + else + Get_First_Interp (Opnd, Index, It); + while Present (It.Typ) loop + if It.Typ = Universal_Integer + or else It.Typ = Universal_Real + then + return It.Typ; + end if; + + Get_Next_Interp (Index, It); + end loop; + + return Empty; + end if; + end Universal_Interpretation; + + ---------------------- + -- Within_Init_Proc -- + ---------------------- + + function Within_Init_Proc return Boolean is + S : Entity_Id; + + begin + S := Current_Scope; + while not Is_Overloadable (S) loop + if S = Standard_Standard then + return False; + else + S := Scope (S); + end if; + end loop; + + return Is_Init_Proc (S); + end Within_Init_Proc; + + ---------------- + -- Wrong_Type -- + ---------------- + + procedure Wrong_Type (Expr : Node_Id; Expected_Type : Entity_Id) is + Found_Type : constant Entity_Id := First_Subtype (Etype (Expr)); + Expec_Type : constant Entity_Id := First_Subtype (Expected_Type); + + function Has_One_Matching_Field return Boolean; + -- Determines if Expec_Type is a record type with a single component or + -- discriminant whose type matches the found type or is one dimensional + -- array whose component type matches the found type. + + ---------------------------- + -- Has_One_Matching_Field -- + ---------------------------- + + function Has_One_Matching_Field return Boolean is + E : Entity_Id; + + begin + if Is_Array_Type (Expec_Type) + and then Number_Dimensions (Expec_Type) = 1 + and then + Covers (Etype (Component_Type (Expec_Type)), Found_Type) + then + return True; + + elsif not Is_Record_Type (Expec_Type) then + return False; + + else + E := First_Entity (Expec_Type); + loop + if No (E) then + return False; + + elsif (Ekind (E) /= E_Discriminant + and then Ekind (E) /= E_Component) + or else (Chars (E) = Name_uTag + or else Chars (E) = Name_uParent) + then + Next_Entity (E); + + else + exit; + end if; + end loop; + + if not Covers (Etype (E), Found_Type) then + return False; + + elsif Present (Next_Entity (E)) then + return False; + + else + return True; + end if; + end if; + end Has_One_Matching_Field; + + -- Start of processing for Wrong_Type + + begin + -- Don't output message if either type is Any_Type, or if a message + -- has already been posted for this node. We need to do the latter + -- check explicitly (it is ordinarily done in Errout), because we + -- are using ! to force the output of the error messages. + + if Expec_Type = Any_Type + or else Found_Type = Any_Type + or else Error_Posted (Expr) + then + return; + + -- In an instance, there is an ongoing problem with completion of + -- type derived from private types. Their structure is what Gigi + -- expects, but the Etype is the parent type rather than the + -- derived private type itself. Do not flag error in this case. The + -- private completion is an entity without a parent, like an Itype. + -- Similarly, full and partial views may be incorrect in the instance. + -- There is no simple way to insure that it is consistent ??? + + elsif In_Instance then + + if Etype (Etype (Expr)) = Etype (Expected_Type) + and then + (Has_Private_Declaration (Expected_Type) + or else Has_Private_Declaration (Etype (Expr))) + and then No (Parent (Expected_Type)) + then + return; + end if; + end if; + + -- An interesting special check. If the expression is parenthesized + -- and its type corresponds to the type of the sole component of the + -- expected record type, or to the component type of the expected one + -- dimensional array type, then assume we have a bad aggregate attempt. + + if Nkind (Expr) in N_Subexpr + and then Paren_Count (Expr) /= 0 + and then Has_One_Matching_Field + then + Error_Msg_N ("positional aggregate cannot have one component", Expr); + + -- Another special check, if we are looking for a pool-specific access + -- type and we found an E_Access_Attribute_Type, then we have the case + -- of an Access attribute being used in a context which needs a pool- + -- specific type, which is never allowed. The one extra check we make + -- is that the expected designated type covers the Found_Type. + + elsif Is_Access_Type (Expec_Type) + and then Ekind (Found_Type) = E_Access_Attribute_Type + and then Ekind (Base_Type (Expec_Type)) /= E_General_Access_Type + and then Ekind (Base_Type (Expec_Type)) /= E_Anonymous_Access_Type + and then Covers + (Designated_Type (Expec_Type), Designated_Type (Found_Type)) + then + Error_Msg_N ("result must be general access type!", Expr); + Error_Msg_NE ("add ALL to }!", Expr, Expec_Type); + + -- If the expected type is an anonymous access type, as for access + -- parameters and discriminants, the error is on the designated types. + + elsif Ekind (Expec_Type) = E_Anonymous_Access_Type then + if Comes_From_Source (Expec_Type) then + Error_Msg_NE ("expected}!", Expr, Expec_Type); + else + Error_Msg_NE + ("expected an access type with designated}", + Expr, Designated_Type (Expec_Type)); + end if; + + if Is_Access_Type (Found_Type) + and then not Comes_From_Source (Found_Type) + then + Error_Msg_NE + ("found an access type with designated}!", + Expr, Designated_Type (Found_Type)); + else + if From_With_Type (Found_Type) then + Error_Msg_NE ("found incomplete}!", Expr, Found_Type); + Error_Msg_NE + ("\possibly missing with_clause on&", Expr, + Scope (Found_Type)); + else + Error_Msg_NE ("found}!", Expr, Found_Type); + end if; + end if; + + -- Normal case of one type found, some other type expected + + else + -- If the names of the two types are the same, see if some + -- number of levels of qualification will help. Don't try + -- more than three levels, and if we get to standard, it's + -- no use (and probably represents an error in the compiler) + -- Also do not bother with internal scope names. + + declare + Expec_Scope : Entity_Id; + Found_Scope : Entity_Id; + + begin + Expec_Scope := Expec_Type; + Found_Scope := Found_Type; + + for Levels in Int range 0 .. 3 loop + if Chars (Expec_Scope) /= Chars (Found_Scope) then + Error_Msg_Qual_Level := Levels; + exit; + end if; + + Expec_Scope := Scope (Expec_Scope); + Found_Scope := Scope (Found_Scope); + + exit when Expec_Scope = Standard_Standard + or else Found_Scope = Standard_Standard + or else not Comes_From_Source (Expec_Scope) + or else not Comes_From_Source (Found_Scope); + end loop; + end; + + if Is_Record_Type (Expec_Type) + and then Present (Corresponding_Remote_Type (Expec_Type)) + then + Error_Msg_NE ("expected}!", Expr, + Corresponding_Remote_Type (Expec_Type)); + else + Error_Msg_NE ("expected}!", Expr, Expec_Type); + end if; + + if Is_Entity_Name (Expr) + and then Is_Package_Or_Generic_Package (Entity (Expr)) + then + Error_Msg_N ("found package name!", Expr); + + elsif Is_Entity_Name (Expr) + and then + (Ekind (Entity (Expr)) = E_Procedure + or else + Ekind (Entity (Expr)) = E_Generic_Procedure) + then + if Ekind (Expec_Type) = E_Access_Subprogram_Type then + Error_Msg_N + ("found procedure name, possibly missing Access attribute!", + Expr); + else + Error_Msg_N ("found procedure name instead of function!", Expr); + end if; + + elsif Nkind (Expr) = N_Function_Call + and then Ekind (Expec_Type) = E_Access_Subprogram_Type + and then Etype (Designated_Type (Expec_Type)) = Etype (Expr) + and then No (Parameter_Associations (Expr)) + then + Error_Msg_N + ("found function name, possibly missing Access attribute!", + Expr); + + -- Catch common error: a prefix or infix operator which is not + -- directly visible because the type isn't. + + elsif Nkind (Expr) in N_Op + and then Is_Overloaded (Expr) + and then not Is_Immediately_Visible (Expec_Type) + and then not Is_Potentially_Use_Visible (Expec_Type) + and then not In_Use (Expec_Type) + and then Has_Compatible_Type (Right_Opnd (Expr), Expec_Type) + then + Error_Msg_N + ("operator of the type is not directly visible!", Expr); + + elsif Ekind (Found_Type) = E_Void + and then Present (Parent (Found_Type)) + and then Nkind (Parent (Found_Type)) = N_Full_Type_Declaration + then + Error_Msg_NE ("found premature usage of}!", Expr, Found_Type); + + else + Error_Msg_NE ("found}!", Expr, Found_Type); + end if; + + Error_Msg_Qual_Level := 0; + end if; + end Wrong_Type; + +end Sem_Util; |