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Diffstat (limited to 'gcc-4.4.3/gcc/ada/sem_util.adb')
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diff --git a/gcc-4.4.3/gcc/ada/sem_util.adb b/gcc-4.4.3/gcc/ada/sem_util.adb new file mode 100644 index 000000000..82dca5662 --- /dev/null +++ b/gcc-4.4.3/gcc/ada/sem_util.adb @@ -0,0 +1,9910 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S E M _ U T I L -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 1992-2008, Free Software Foundation, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 3, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- +-- for more details. You should have received a copy of the GNU General -- +-- Public License distributed with GNAT; see file COPYING3. If not, go to -- +-- http://www.gnu.org/licenses for a complete copy of the license. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- -- +------------------------------------------------------------------------------ + +with Atree; use Atree; +with Casing; use Casing; +with Checks; use Checks; +with Debug; use Debug; +with Errout; use Errout; +with Elists; use Elists; +with Exp_Disp; use Exp_Disp; +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 Nlists; use Nlists; +with Output; use Output; +with Opt; use Opt; +with Rtsfind; use Rtsfind; +with Scans; use Scans; +with Scn; use Scn; +with Sem; use Sem; +with Sem_Attr; use Sem_Attr; +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 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. + + ------------------------------ + -- Abstract_Interface_List -- + ------------------------------ + + function Abstract_Interface_List (Typ : Entity_Id) return List_Id is + Nod : Node_Id; + + begin + if Is_Concurrent_Type (Typ) then + + -- If we are dealing with a synchronized subtype, go to the base + -- type, whose declaration has the interface list. + + -- Shouldn't this be Declaration_Node??? + + Nod := Parent (Base_Type (Typ)); + + if Nkind (Nod) = N_Full_Type_Declaration then + return Empty_List; + end if; + + elsif Ekind (Typ) = E_Record_Type_With_Private then + if Nkind (Parent (Typ)) = N_Full_Type_Declaration then + Nod := Type_Definition (Parent (Typ)); + + elsif Nkind (Parent (Typ)) = N_Private_Type_Declaration then + if Present (Full_View (Typ)) then + Nod := Type_Definition (Parent (Full_View (Typ))); + + -- If the full-view is not available we cannot do anything else + -- here (the source has errors). + + else + return Empty_List; + end if; + + -- Support for generic formals with interfaces is still missing ??? + + elsif Nkind (Parent (Typ)) = N_Formal_Type_Declaration then + return Empty_List; + + else + pragma Assert + (Nkind (Parent (Typ)) = N_Private_Extension_Declaration); + Nod := Parent (Typ); + end if; + + elsif Ekind (Typ) = E_Record_Subtype then + Nod := Type_Definition (Parent (Etype (Typ))); + + elsif Ekind (Typ) = E_Record_Subtype_With_Private then + + -- Recurse, because parent may still be a private extension. Also + -- note that the full view of the subtype or the full view of its + -- base type may (both) be unavailable. + + return Abstract_Interface_List (Etype (Typ)); + + else pragma Assert ((Ekind (Typ)) = E_Record_Type); + if Nkind (Parent (Typ)) = N_Formal_Type_Declaration then + Nod := Formal_Type_Definition (Parent (Typ)); + else + Nod := Type_Definition (Parent (Typ)); + end if; + end if; + + return Interface_List (Nod); + end Abstract_Interface_List; + + -------------------------------- + -- 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; + + ---------------------------- + -- Add_Global_Declaration -- + ---------------------------- + + procedure Add_Global_Declaration (N : Node_Id) is + Aux_Node : constant Node_Id := Aux_Decls_Node (Cunit (Current_Sem_Unit)); + + begin + if No (Declarations (Aux_Node)) then + Set_Declarations (Aux_Node, New_List); + end if; + + Append_To (Declarations (Aux_Node), N); + Analyze (N); + end Add_Global_Declaration; + + ----------------------- + -- 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); + R_Stat : constant Node_Id := + Make_Raise_Constraint_Error (Sloc (N), Reason => Reason); + 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, R_Stat); + 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 + Loc : Source_Ptr; + -- Normally Sloc (N), but may point to corresponding body in some cases + + Constraints : List_Id; + Decl : Node_Id; + Discr : Entity_Id; + Hi : Node_Id; + Lo : Node_Id; + Subt : Entity_Id; + Disc_Type : Entity_Id; + Obj : Node_Id; + + begin + Loc := Sloc (N); + + if Nkind (N) = N_Defining_Identifier then + Obj := New_Reference_To (N, Loc); + + -- If this is a formal parameter of a subprogram declaration, and + -- we are compiling the body, we want the declaration for the + -- actual subtype to carry the source position of the body, to + -- prevent anomalies in gdb when stepping through the code. + + if Is_Formal (N) then + declare + Decl : constant Node_Id := Unit_Declaration_Node (Scope (N)); + begin + if Nkind (Decl) = N_Subprogram_Declaration + and then Present (Corresponding_Body (Decl)) + then + Loc := Sloc (Corresponding_Body (Decl)); + end if; + end; + end if; + + 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; + + -- Type T is a generic derived type, inherit the discriminants from + -- the parent type. + + if Is_Private_Type (T) + and then No (Full_View (T)) + + -- T was flagged as an error if it was declared as a formal + -- derived type with known discriminants. In this case there + -- is no need to look at the parent type since T already carries + -- its own discriminants. + + and then not Error_Posted (T) + then + 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 + -- Why the test for Spec_Expression mode here??? + + if In_Spec_Expression then + return Empty; + + -- More comments for the rest of this body would be good ??? + + 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_Default_Subtype -- + --------------------------- + + function Build_Default_Subtype + (T : Entity_Id; + N : Node_Id) return Entity_Id + is + Loc : constant Source_Ptr := Sloc (N); + Disc : Entity_Id; + + begin + if not Has_Discriminants (T) or else Is_Constrained (T) then + return T; + end if; + + Disc := First_Discriminant (T); + + if No (Discriminant_Default_Value (Disc)) then + return T; + end if; + + declare + Act : constant Entity_Id := + Make_Defining_Identifier (Loc, + Chars => New_Internal_Name ('S')); + + Constraints : constant List_Id := New_List; + Decl : Node_Id; + + begin + while Present (Disc) loop + Append_To (Constraints, + New_Copy_Tree (Discriminant_Default_Value (Disc))); + Next_Discriminant (Disc); + end loop; + + Decl := + Make_Subtype_Declaration (Loc, + Defining_Identifier => Act, + Subtype_Indication => + Make_Subtype_Indication (Loc, + Subtype_Mark => New_Occurrence_Of (T, Loc), + Constraint => + Make_Index_Or_Discriminant_Constraint (Loc, + Constraints => Constraints))); + + Insert_Action (N, Decl); + Analyze (Decl); + return Act; + end; + end Build_Default_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); + Decl : Node_Id; + Elab_Ent : Entity_Id; + + procedure Set_Package_Name (Ent : Entity_Id); + -- Given an entity, sets the fully qualified name of the entity in + -- Name_Buffer, with components separated by double underscores. This + -- is a recursive routine that climbs the scope chain to Standard. + + ---------------------- + -- Set_Package_Name -- + ---------------------- + + procedure Set_Package_Name (Ent : Entity_Id) is + begin + if Scope (Ent) /= Standard_Standard then + Set_Package_Name (Scope (Ent)); + + declare + Nam : constant String := Get_Name_String (Chars (Ent)); + begin + Name_Buffer (Name_Len + 1) := '_'; + Name_Buffer (Name_Len + 2) := '_'; + Name_Buffer (Name_Len + 3 .. Name_Len + Nam'Length + 2) := Nam; + Name_Len := Name_Len + Nam'Length + 2; + end; + + else + Get_Name_String (Chars (Ent)); + end if; + end Set_Package_Name; + + -- Start of processing for Build_Elaboration_Entity + + 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. + + Set_Package_Name (Spec_Id); + + -- Append _E + + Name_Buffer (Name_Len + 1) := '_'; + Name_Buffer (Name_Len + 2) := 'E'; + Name_Len := Name_Len + 2; + + -- Create elaboration flag + + Elab_Ent := + Make_Defining_Identifier (Loc, Chars => Name_Find); + Set_Elaboration_Entity (Spec_Id, Elab_Ent); + + Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => Elab_Ent, + Object_Definition => + New_Occurrence_Of (Standard_Boolean, Loc), + Expression => + New_Occurrence_Of (Standard_False, Loc)); + + Push_Scope (Standard_Standard); + Add_Global_Declaration (Decl); + Pop_Scope; + + -- Reset True_Constant indication, since we will indeed assign a value + -- to the variable in the binder main. We also kill the Current_Value + -- and Last_Assignment fields for the same reason. + + Set_Is_True_Constant (Elab_Ent, False); + Set_Current_Value (Elab_Ent, Empty); + Set_Last_Assignment (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; + + begin + N := First (Expressions (Expr)); + 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; + + -- Need comments for these tests ??? + + elsif Has_Private_Component (T) + and then not Is_Generic_Type (Root_Type (T)) + and then not In_Spec_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_Nested_Access -- + ------------------------- + + procedure Check_Nested_Access (Ent : Entity_Id) is + Scop : constant Entity_Id := Current_Scope; + Current_Subp : Entity_Id; + Enclosing : Entity_Id; + + begin + -- Currently only enabled for VM back-ends for efficiency, should we + -- enable it more systematically ??? + + -- Check for Is_Imported needs commenting below ??? + + if VM_Target /= No_VM + and then (Ekind (Ent) = E_Variable + or else + Ekind (Ent) = E_Constant + or else + Ekind (Ent) = E_Loop_Parameter) + and then Scope (Ent) /= Empty + and then not Is_Library_Level_Entity (Ent) + and then not Is_Imported (Ent) + then + if Is_Subprogram (Scop) + or else Is_Generic_Subprogram (Scop) + or else Is_Entry (Scop) + then + Current_Subp := Scop; + else + Current_Subp := Current_Subprogram; + end if; + + Enclosing := Enclosing_Subprogram (Ent); + + if Enclosing /= Empty + and then Enclosing /= Current_Subp + then + Set_Has_Up_Level_Access (Ent, True); + end if; + end if; + end Check_Nested_Access; + + ------------------------------------------ + -- 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_Unprotected_Access -- + ------------------------------ + + procedure Check_Unprotected_Access + (Context : Node_Id; + Expr : Node_Id) + is + Cont_Encl_Typ : Entity_Id; + Pref_Encl_Typ : Entity_Id; + + function Enclosing_Protected_Type (Obj : Node_Id) return Entity_Id; + -- Check whether Obj is a private component of a protected object. + -- Return the protected type where the component resides, Empty + -- otherwise. + + function Is_Public_Operation return Boolean; + -- Verify that the enclosing operation is callable from outside the + -- protected object, to minimize false positives. + + ------------------------------ + -- Enclosing_Protected_Type -- + ------------------------------ + + function Enclosing_Protected_Type (Obj : Node_Id) return Entity_Id is + begin + if Is_Entity_Name (Obj) then + declare + Ent : Entity_Id := Entity (Obj); + + begin + -- The object can be a renaming of a private component, use + -- the original record component. + + if Is_Prival (Ent) then + Ent := Prival_Link (Ent); + end if; + + if Is_Protected_Type (Scope (Ent)) then + return Scope (Ent); + end if; + end; + end if; + + -- For indexed and selected components, recursively check the prefix + + if Nkind_In (Obj, N_Indexed_Component, N_Selected_Component) then + return Enclosing_Protected_Type (Prefix (Obj)); + + -- The object does not denote a protected component + + else + return Empty; + end if; + end Enclosing_Protected_Type; + + ------------------------- + -- Is_Public_Operation -- + ------------------------- + + function Is_Public_Operation return Boolean is + S : Entity_Id; + E : Entity_Id; + + begin + S := Current_Scope; + while Present (S) + and then S /= Pref_Encl_Typ + loop + if Scope (S) = Pref_Encl_Typ then + E := First_Entity (Pref_Encl_Typ); + while Present (E) + and then E /= First_Private_Entity (Pref_Encl_Typ) + loop + if E = S then + return True; + end if; + Next_Entity (E); + end loop; + end if; + + S := Scope (S); + end loop; + + return False; + end Is_Public_Operation; + + -- Start of processing for Check_Unprotected_Access + + begin + if Nkind (Expr) = N_Attribute_Reference + and then Attribute_Name (Expr) = Name_Unchecked_Access + then + Cont_Encl_Typ := Enclosing_Protected_Type (Context); + Pref_Encl_Typ := Enclosing_Protected_Type (Prefix (Expr)); + + -- Check whether we are trying to export a protected component to a + -- context with an equal or lower access level. + + if Present (Pref_Encl_Typ) + and then No (Cont_Encl_Typ) + and then Is_Public_Operation + and then Scope_Depth (Pref_Encl_Typ) >= + Object_Access_Level (Context) + then + Error_Msg_N + ("?possible unprotected access to protected data", Expr); + end if; + end if; + end Check_Unprotected_Access; + + --------------- + -- 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_Interfaces -- + ------------------------ + + procedure Collect_Interfaces + (T : Entity_Id; + Ifaces_List : out Elist_Id; + Exclude_Parents : Boolean := False; + Use_Full_View : Boolean := True) + is + procedure Collect (Typ : Entity_Id); + -- Subsidiary subprogram used to traverse the whole list + -- of directly and indirectly implemented interfaces + + ------------- + -- Collect -- + ------------- + + procedure Collect (Typ : Entity_Id) is + Ancestor : Entity_Id; + Full_T : Entity_Id; + Id : Node_Id; + Iface : Entity_Id; + + begin + Full_T := Typ; + + -- Handle private types + + if Use_Full_View + and then Is_Private_Type (Typ) + and then Present (Full_View (Typ)) + then + Full_T := Full_View (Typ); + end if; + + -- Include the ancestor if we are generating the whole list of + -- abstract interfaces. + + if Etype (Full_T) /= Typ + + -- Protect the frontend against wrong sources. For example: + + -- package P is + -- type A is tagged null record; + -- type B is new A with private; + -- type C is new A with private; + -- private + -- type B is new C with null record; + -- type C is new B with null record; + -- end P; + + and then Etype (Full_T) /= T + then + Ancestor := Etype (Full_T); + Collect (Ancestor); + + if Is_Interface (Ancestor) + and then not Exclude_Parents + then + Append_Unique_Elmt (Ancestor, Ifaces_List); + end if; + end if; + + -- Traverse the graph of ancestor interfaces + + if Is_Non_Empty_List (Abstract_Interface_List (Full_T)) then + Id := First (Abstract_Interface_List (Full_T)); + while Present (Id) loop + Iface := Etype (Id); + + -- Protect against wrong uses. For example: + -- type I is interface; + -- type O is tagged null record; + -- type Wrong is new I and O with null record; -- ERROR + + if Is_Interface (Iface) then + if Exclude_Parents + and then Etype (T) /= T + and then Interface_Present_In_Ancestor (Etype (T), Iface) + then + null; + else + Collect (Iface); + Append_Unique_Elmt (Iface, Ifaces_List); + end if; + end if; + + Next (Id); + end loop; + end if; + end Collect; + + -- Start of processing for Collect_Interfaces + + begin + pragma Assert (Is_Tagged_Type (T) or else Is_Concurrent_Type (T)); + Ifaces_List := New_Elmt_List; + Collect (T); + end Collect_Interfaces; + + ---------------------------------- + -- Collect_Interface_Components -- + ---------------------------------- + + procedure Collect_Interface_Components + (Tagged_Type : Entity_Id; + Components_List : out Elist_Id) + is + procedure Collect (Typ : Entity_Id); + -- Subsidiary subprogram used to climb to the parents + + ------------- + -- Collect -- + ------------- + + procedure Collect (Typ : Entity_Id) is + Tag_Comp : Entity_Id; + + begin + if Etype (Typ) /= Typ + + -- Protect the frontend against wrong sources. For example: + + -- package P is + -- type A is tagged null record; + -- type B is new A with private; + -- type C is new A with private; + -- private + -- type B is new C with null record; + -- type C is new B with null record; + -- end P; + + and then Etype (Typ) /= Tagged_Type + then + Collect (Etype (Typ)); + end if; + + -- Collect the components containing tags of secondary dispatch + -- tables. + + Tag_Comp := Next_Tag_Component (First_Tag_Component (Typ)); + while Present (Tag_Comp) loop + pragma Assert (Present (Related_Type (Tag_Comp))); + Append_Elmt (Tag_Comp, Components_List); + + Tag_Comp := Next_Tag_Component (Tag_Comp); + end loop; + end Collect; + + -- Start of processing for Collect_Interface_Components + + begin + pragma Assert (Ekind (Tagged_Type) = E_Record_Type + and then Is_Tagged_Type (Tagged_Type)); + + Components_List := New_Elmt_List; + Collect (Tagged_Type); + end Collect_Interface_Components; + + ----------------------------- + -- Collect_Interfaces_Info -- + ----------------------------- + + procedure Collect_Interfaces_Info + (T : Entity_Id; + Ifaces_List : out Elist_Id; + Components_List : out Elist_Id; + Tags_List : out Elist_Id) + is + Comps_List : Elist_Id; + Comp_Elmt : Elmt_Id; + Comp_Iface : Entity_Id; + Iface_Elmt : Elmt_Id; + Iface : Entity_Id; + + function Search_Tag (Iface : Entity_Id) return Entity_Id; + -- Search for the secondary tag associated with the interface type + -- Iface that is implemented by T. + + ---------------- + -- Search_Tag -- + ---------------- + + function Search_Tag (Iface : Entity_Id) return Entity_Id is + ADT : Elmt_Id; + + begin + ADT := Next_Elmt (Next_Elmt (First_Elmt (Access_Disp_Table (T)))); + while Present (ADT) + and then Ekind (Node (ADT)) = E_Constant + and then Related_Type (Node (ADT)) /= Iface + loop + -- Skip the secondary dispatch tables of Iface + + Next_Elmt (ADT); + Next_Elmt (ADT); + Next_Elmt (ADT); + Next_Elmt (ADT); + end loop; + + pragma Assert (Ekind (Node (ADT)) = E_Constant); + return Node (ADT); + end Search_Tag; + + -- Start of processing for Collect_Interfaces_Info + + begin + Collect_Interfaces (T, Ifaces_List); + Collect_Interface_Components (T, Comps_List); + + -- Search for the record component and tag associated with each + -- interface type of T. + + Components_List := New_Elmt_List; + Tags_List := New_Elmt_List; + + Iface_Elmt := First_Elmt (Ifaces_List); + while Present (Iface_Elmt) loop + Iface := Node (Iface_Elmt); + + -- Associate the primary tag component and the primary dispatch table + -- with all the interfaces that are parents of T + + if Is_Ancestor (Iface, T) then + Append_Elmt (First_Tag_Component (T), Components_List); + Append_Elmt (Node (First_Elmt (Access_Disp_Table (T))), Tags_List); + + -- Otherwise search for the tag component and secondary dispatch + -- table of Iface + + else + Comp_Elmt := First_Elmt (Comps_List); + while Present (Comp_Elmt) loop + Comp_Iface := Related_Type (Node (Comp_Elmt)); + + if Comp_Iface = Iface + or else Is_Ancestor (Iface, Comp_Iface) + then + Append_Elmt (Node (Comp_Elmt), Components_List); + Append_Elmt (Search_Tag (Comp_Iface), Tags_List); + exit; + end if; + + Next_Elmt (Comp_Elmt); + end loop; + pragma Assert (Present (Comp_Elmt)); + end if; + + Next_Elmt (Iface_Elmt); + end loop; + end Collect_Interfaces_Info; + + ---------------------------------- + -- 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); + -- Copy of message, with room for possible ? and ! at end + + 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; + + Msgc (1 .. Msg'Length) := Msg; + Msgl := Msg'Length; + + -- Message is a warning, even in Ada 95 case + + if Msg (Msg'Last) = '?' 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) + -- and we make this an unconditional message. Note that in the + -- warning case we do not make the message unconditional, it seems + -- quite reasonable to delete messages like this (about exceptions + -- that will be raised) in dead code. + + else + Wmsg := False; + Msgl := Msgl + 1; + Msgc (Msgl) := '!'; + 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 + ("\static expression fails Constraint_Check", Eloc); + Set_Error_Posted (N); + 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; + + ------------------------- + -- Copy_Parameter_List -- + ------------------------- + + function Copy_Parameter_List (Subp_Id : Entity_Id) return List_Id is + Loc : constant Source_Ptr := Sloc (Subp_Id); + Plist : List_Id; + Formal : Entity_Id; + + begin + if No (First_Formal (Subp_Id)) then + return No_List; + else + Plist := New_List; + Formal := First_Formal (Subp_Id); + while Present (Formal) loop + Append + (Make_Parameter_Specification (Loc, + Defining_Identifier => + Make_Defining_Identifier (Sloc (Formal), + Chars => Chars (Formal)), + In_Present => In_Present (Parent (Formal)), + Out_Present => Out_Present (Parent (Formal)), + Parameter_Type => + New_Reference_To (Etype (Formal), Loc), + Expression => + New_Copy_Tree (Expression (Parent (Formal)))), + Plist); + + Next_Formal (Formal); + end loop; + end if; + + return Plist; + end Copy_Parameter_List; + + -------------------- + -- 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_Concurrent : 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_Concurrent + and then Ekind (E) = E_In_Parameter + and then Present (Discriminal_Link (E)) + and then + (Is_Concurrent_Type (Scope (Discriminal_Link (E))) + or else + Is_Concurrent_Record_Type (Scope (Discriminal_Link (E))))); + + end Denotes_Discriminant; + + ---------------------- + -- Denotes_Variable -- + ---------------------- + + function Denotes_Variable (N : Node_Id) return Boolean is + begin + return Is_Variable (N) and then Paren_Count (N) = 0; + end Denotes_Variable; + + ----------------------------- + -- 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; + + begin + -- Look for enclosing library unit entity by following scope links. + -- Equivalent to, but faster than indexing through the scope stack. + + Unit_Entity := Current_Scope; + 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; + + begin + Current_Node := N; + 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 Dynamic_Scope = Empty then + return Empty; + + elsif Ekind (Dynamic_Scope) = E_Subprogram_Body then + return Corresponding_Spec (Parent (Parent (Dynamic_Scope))); + + elsif Ekind (Dynamic_Scope) = E_Block + or else Ekind (Dynamic_Scope) = E_Return_Statement + 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; + + 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; + + -- If the homograph is a protected component renaming, it should not + -- be hiding the current entity. Such renamings are treated as weak + -- declarations. + + elsif Is_Prival (E) then + Set_Is_Immediately_Visible (E, False); + + -- In this case the current entity is a protected component renaming. + -- Perform minimal decoration by setting the scope and return since + -- the prival should not be hiding other visible entities. + + elsif Is_Prival (Def_Id) then + Set_Scope (Def_Id, Current_Scope); + return; + + -- Analogous to privals, the discriminal generated for an entry + -- index parameter acts as a weak declaration. Perform minimal + -- decoration to avoid bogus errors. + + elsif Is_Discriminal (Def_Id) + and then Ekind (Discriminal_Link (Def_Id)) = E_Entry_Index_Parameter + then + Set_Scope (Def_Id, Current_Scope); + 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); + + -- 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. + + elsif Ekind (E) = E_Discriminant + and then Present (Scope (Def_Id)) + and then Scope (Def_Id) /= Current_Scope + then + 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) + + -- Don't warn for record components since they always have a well + -- defined scope which does not confuse other uses. Note that in + -- some cases, Ekind has not been set yet. + + and then Ekind (C) /= E_Component + and then Ekind (C) /= E_Discriminant + and then Nkind (Parent (C)) /= N_Component_Declaration + and then Ekind (Def_Id) /= E_Component + and then Ekind (Def_Id) /= E_Discriminant + and then Nkind (Parent (Def_Id)) /= N_Component_Declaration + + -- Don't warn for one character variables. It is too common to use + -- such variables as locals and will just cause too many false hits. + + and then Length_Of_Name (Chars (C)) /= 1 + + -- Don't warn for non-source entities + + and then Comes_From_Source (C) + and then Comes_From_Source (Def_Id) + + -- Don't warn unless entity in question is in extended main source + + and then In_Extended_Main_Source_Unit (Def_Id) + + -- Finally, the hidden entity must be either immediately visible + -- or use visible (from a used package) + + and then + (Is_Immediately_Visible (C) + or else + Is_Potentially_Use_Visible (C)) + 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_Actual -- + ----------------- + + procedure Find_Actual + (N : Node_Id; + Formal : out Entity_Id; + Call : out Node_Id) + is + Parnt : constant Node_Id := Parent (N); + Actual : Node_Id; + + begin + if (Nkind (Parnt) = N_Indexed_Component + or else + Nkind (Parnt) = N_Selected_Component) + and then N = Prefix (Parnt) + then + Find_Actual (Parnt, Formal, Call); + return; + + elsif Nkind (Parnt) = N_Parameter_Association + and then N = Explicit_Actual_Parameter (Parnt) + then + Call := Parent (Parnt); + + elsif Nkind (Parnt) = N_Procedure_Call_Statement then + Call := Parnt; + + else + Formal := Empty; + Call := Empty; + return; + end if; + + -- If we have a call to a subprogram look for the parameter. Note that + -- we exclude overloaded calls, since we don't know enough to be sure + -- of giving the right answer in this case. + + if Is_Entity_Name (Name (Call)) + and then Present (Entity (Name (Call))) + and then Is_Overloadable (Entity (Name (Call))) + and then not Is_Overloaded (Name (Call)) + then + -- Fall here if we are definitely a parameter + + Actual := First_Actual (Call); + Formal := First_Formal (Entity (Name (Call))); + while Present (Formal) and then Present (Actual) loop + if Actual = N then + return; + else + Actual := Next_Actual (Actual); + Formal := Next_Formal (Formal); + end if; + end loop; + end if; + + -- Fall through here if we did not find matching actual + + Formal := Empty; + Call := Empty; + end Find_Actual; + + ------------------------------------- + -- 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_Overlaid_Object -- + -------------------------- + + function Find_Overlaid_Object (N : Node_Id) return Entity_Id is + Expr : Node_Id; + + begin + -- We are looking for one of the two following forms: + + -- for X'Address use Y'Address + + -- or + + -- Const : constant Address := expr; + -- ... + -- for X'Address use Const; + + -- In the second case, the expr is either Y'Address, or recursively a + -- constant that eventually references Y'Address. + + if Nkind (N) = N_Attribute_Definition_Clause + and then Chars (N) = Name_Address + then + -- This loop checks the form of the expression for Y'Address where Y + -- is an object entity name. The first loop checks the original + -- expression in the attribute definition clause. Subsequent loops + -- check referenced constants. + + Expr := Expression (N); + loop + -- Check for Y'Address where Y is an object entity + + if Nkind (Expr) = N_Attribute_Reference + and then Attribute_Name (Expr) = Name_Address + and then Is_Entity_Name (Prefix (Expr)) + and then Is_Object (Entity (Prefix (Expr))) + then + return Entity (Prefix (Expr)); + + -- Check for Const where Const is a constant entity + + elsif Is_Entity_Name (Expr) + and then Ekind (Entity (Expr)) = E_Constant + then + Expr := Constant_Value (Entity (Expr)); + + -- Anything else does not need checking + + else + exit; + end if; + end loop; + end if; + + return Empty; + end Find_Overlaid_Object; + + ------------------------- + -- Find_Parameter_Type -- + ------------------------- + + function Find_Parameter_Type (Param : Node_Id) return Entity_Id is + begin + if Nkind (Param) /= N_Parameter_Specification then + return Empty; + + -- For an access parameter, obtain the type from the formal entity + -- itself, because access to subprogram nodes do not carry a type. + -- Shouldn't we always use the formal entity ??? + + elsif Nkind (Parameter_Type (Param)) = N_Access_Definition then + return Etype (Defining_Identifier (Param)); + + else + return Etype (Parameter_Type (Param)); + end if; + end Find_Parameter_Type; + + ----------------------------- + -- 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; + + 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 spec expression (why not???) + + if In_Spec_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 Is_Standard_Character_Type (T) 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_Pragma_Id -- + ------------------- + + function Get_Pragma_Id (N : Node_Id) return Pragma_Id is + begin + return Get_Pragma_Id (Pragma_Name (N)); + end Get_Pragma_Id; + + --------------------------- + -- Get_Referenced_Object -- + --------------------------- + + function Get_Referenced_Object (N : Node_Id) return Node_Id is + R : Node_Id; + + begin + R := N; + 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_Renamed_Entity -- + ------------------------ + + function Get_Renamed_Entity (E : Entity_Id) return Entity_Id is + R : Entity_Id; + + begin + R := E; + while Present (Renamed_Entity (R)) loop + R := Renamed_Entity (R); + end loop; + + return R; + end Get_Renamed_Entity; + + ------------------------- + -- 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_Subprogram_Entity -- + --------------------------- + + function Get_Subprogram_Entity (Nod : Node_Id) return Entity_Id is + Nam : Node_Id; + Proc : Entity_Id; + + begin + if Nkind (Nod) = N_Accept_Statement then + Nam := Entry_Direct_Name (Nod); + + -- For an entry call, the prefix of the call is a selected component. + -- Need additional code for internal calls ??? + + elsif Nkind (Nod) = N_Entry_Call_Statement then + if Nkind (Name (Nod)) = N_Selected_Component then + Nam := Entity (Selector_Name (Name (Nod))); + else + Nam := Empty; + end if; + + else + Nam := Name (Nod); + end if; + + if Nkind (Nam) = N_Explicit_Dereference then + Proc := Etype (Prefix (Nam)); + elsif Is_Entity_Name (Nam) then + Proc := Entity (Nam); + else + return Empty; + end if; + + if Is_Object (Proc) then + Proc := Etype (Proc); + end if; + + if Ekind (Proc) = E_Access_Subprogram_Type then + Proc := Directly_Designated_Type (Proc); + end if; + + if not Is_Subprogram (Proc) + and then Ekind (Proc) /= E_Subprogram_Type + then + return Empty; + else + return Proc; + end if; + end Get_Subprogram_Entity; + + ----------------------------- + -- 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. + + -- This is an odd function, why not have Task_Body_Procedure do + -- the following digging??? + + 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 + -- Loop to Check components + + Comp := First_Component_Or_Discriminant (Typ); + while Present (Comp) loop + + -- Check for access component, tag field does not count, even + -- though it is implemented internally using an access type. + + if Has_Access_Values (Etype (Comp)) + and then Chars (Comp) /= Name_uTag + then + return True; + end if; + + Next_Component_Or_Discriminant (Comp); + end loop; + end; + + return False; + + else + return False; + end if; + end Has_Access_Values; + + ------------------------------ + -- Has_Compatible_Alignment -- + ------------------------------ + + function Has_Compatible_Alignment + (Obj : Entity_Id; + Expr : Node_Id) return Alignment_Result + is + function Has_Compatible_Alignment_Internal + (Obj : Entity_Id; + Expr : Node_Id; + Default : Alignment_Result) return Alignment_Result; + -- This is the internal recursive function that actually does the work. + -- There is one additional parameter, which says what the result should + -- be if no alignment information is found, and there is no definite + -- indication of compatible alignments. At the outer level, this is set + -- to Unknown, but for internal recursive calls in the case where types + -- are known to be correct, it is set to Known_Compatible. + + --------------------------------------- + -- Has_Compatible_Alignment_Internal -- + --------------------------------------- + + function Has_Compatible_Alignment_Internal + (Obj : Entity_Id; + Expr : Node_Id; + Default : Alignment_Result) return Alignment_Result + is + Result : Alignment_Result := Known_Compatible; + -- Set to result if Problem_Prefix or Problem_Offset returns True. + -- Note that once a value of Known_Incompatible is set, it is sticky + -- and does not get changed to Unknown (the value in Result only gets + -- worse as we go along, never better). + + procedure Check_Offset (Offs : Uint); + -- Called when Expr is a selected or indexed component with Offs set + -- to resp Component_First_Bit or Component_Size. Checks that if the + -- offset is specified it is compatible with the object alignment + -- requirements. The value in Result is modified accordingly. + + procedure Check_Prefix; + -- Checks the prefix recursively in the case where the expression + -- is an indexed or selected component. + + procedure Set_Result (R : Alignment_Result); + -- If R represents a worse outcome (unknown instead of known + -- compatible, or known incompatible), then set Result to R. + + ------------------ + -- Check_Offset -- + ------------------ + + procedure Check_Offset (Offs : Uint) is + begin + -- Unspecified or zero offset is always OK + + if Offs = No_Uint or else Offs = Uint_0 then + null; + + -- If we do not know required alignment, any non-zero offset is + -- a potential problem (but certainly may be OK, so result is + -- unknown). + + elsif Unknown_Alignment (Obj) then + Set_Result (Unknown); + + -- If we know the required alignment, see if offset is compatible + + else + if Offs mod (System_Storage_Unit * Alignment (Obj)) /= 0 then + Set_Result (Known_Incompatible); + end if; + end if; + end Check_Offset; + + ------------------ + -- Check_Prefix -- + ------------------ + + procedure Check_Prefix is + begin + -- The subtlety here is that in doing a recursive call to check + -- the prefix, we have to decide what to do in the case where we + -- don't find any specific indication of an alignment problem. + + -- At the outer level, we normally set Unknown as the result in + -- this case, since we can only set Known_Compatible if we really + -- know that the alignment value is OK, but for the recursive + -- call, in the case where the types match, and we have not + -- specified a peculiar alignment for the object, we are only + -- concerned about suspicious rep clauses, the default case does + -- not affect us, since the compiler will, in the absence of such + -- rep clauses, ensure that the alignment is correct. + + if Default = Known_Compatible + or else + (Etype (Obj) = Etype (Expr) + and then (Unknown_Alignment (Obj) + or else + Alignment (Obj) = Alignment (Etype (Obj)))) + then + Set_Result + (Has_Compatible_Alignment_Internal + (Obj, Prefix (Expr), Known_Compatible)); + + -- In all other cases, we need a full check on the prefix + + else + Set_Result + (Has_Compatible_Alignment_Internal + (Obj, Prefix (Expr), Unknown)); + end if; + end Check_Prefix; + + ---------------- + -- Set_Result -- + ---------------- + + procedure Set_Result (R : Alignment_Result) is + begin + if R > Result then + Result := R; + end if; + end Set_Result; + + -- Start of processing for Has_Compatible_Alignment_Internal + + begin + -- If Expr is a selected component, we must make sure there is no + -- potentially troublesome component clause, and that the record is + -- not packed. + + if Nkind (Expr) = N_Selected_Component then + + -- Packed record always generate unknown alignment + + if Is_Packed (Etype (Prefix (Expr))) then + Set_Result (Unknown); + end if; + + -- Check possible bad component offset and check prefix + + Check_Offset + (Component_Bit_Offset (Entity (Selector_Name (Expr)))); + Check_Prefix; + + -- If Expr is an indexed component, we must make sure there is no + -- potentially troublesome Component_Size clause and that the array + -- is not bit-packed. + + elsif Nkind (Expr) = N_Indexed_Component then + + -- Bit packed array always generates unknown alignment + + if Is_Bit_Packed_Array (Etype (Prefix (Expr))) then + Set_Result (Unknown); + end if; + + -- Check possible bad component size and check prefix + + Check_Offset (Component_Size (Etype (Prefix (Expr)))); + Check_Prefix; + end if; + + -- Case where we know the alignment of the object + + if Known_Alignment (Obj) then + declare + ObjA : constant Uint := Alignment (Obj); + ExpA : Uint := No_Uint; + SizA : Uint := No_Uint; + + begin + -- If alignment of Obj is 1, then we are always OK + + if ObjA = 1 then + Set_Result (Known_Compatible); + + -- Alignment of Obj is greater than 1, so we need to check + + else + -- See if Expr is an object with known alignment + + if Is_Entity_Name (Expr) + and then Known_Alignment (Entity (Expr)) + then + ExpA := Alignment (Entity (Expr)); + + -- Otherwise, we can use the alignment of the type of + -- Expr given that we already checked for + -- discombobulating rep clauses for the cases of indexed + -- and selected components above. + + elsif Known_Alignment (Etype (Expr)) then + ExpA := Alignment (Etype (Expr)); + end if; + + -- If we got an alignment, see if it is acceptable + + if ExpA /= No_Uint then + if ExpA < ObjA then + Set_Result (Known_Incompatible); + end if; + + -- Case of Expr alignment unknown + + else + Set_Result (Default); + end if; + + -- See if size is given. If so, check that it is not too + -- small for the required alignment. + -- See if Expr is an object with known alignment + + if Is_Entity_Name (Expr) + and then Known_Static_Esize (Entity (Expr)) + then + SizA := Esize (Entity (Expr)); + + -- Otherwise, we check the object size of the Expr type + + elsif Known_Static_Esize (Etype (Expr)) then + SizA := Esize (Etype (Expr)); + end if; + + -- If we got a size, see if it is a multiple of the Obj + -- alignment, if not, then the alignment cannot be + -- acceptable, since the size is always a multiple of the + -- alignment. + + if SizA /= No_Uint then + if SizA mod (ObjA * Ttypes.System_Storage_Unit) /= 0 then + Set_Result (Known_Incompatible); + end if; + end if; + end if; + end; + + -- If we can't find the result by direct comparison of alignment + -- values, then there is still one case that we can determine known + -- result, and that is when we can determine that the types are the + -- same, and no alignments are specified. Then we known that the + -- alignments are compatible, even if we don't know the alignment + -- value in the front end. + + elsif Etype (Obj) = Etype (Expr) then + + -- Types are the same, but we have to check for possible size + -- and alignments on the Expr object that may make the alignment + -- different, even though the types are the same. + + if Is_Entity_Name (Expr) then + + -- First check alignment of the Expr object. Any alignment less + -- than Maximum_Alignment is worrisome since this is the case + -- where we do not know the alignment of Obj. + + if Known_Alignment (Entity (Expr)) + and then + UI_To_Int (Alignment (Entity (Expr))) + < Ttypes.Maximum_Alignment + then + Set_Result (Unknown); + + -- Now check size of Expr object. Any size that is not an + -- even multiple of Maximum_Alignment is also worrisome + -- since it may cause the alignment of the object to be less + -- than the alignment of the type. + + elsif Known_Static_Esize (Entity (Expr)) + and then + (UI_To_Int (Esize (Entity (Expr))) mod + (Ttypes.Maximum_Alignment * Ttypes.System_Storage_Unit)) + /= 0 + then + Set_Result (Unknown); + + -- Otherwise same type is decisive + + else + Set_Result (Known_Compatible); + end if; + end if; + + -- Another case to deal with is when there is an explicit size or + -- alignment clause when the types are not the same. If so, then the + -- result is Unknown. We don't need to do this test if the Default is + -- Unknown, since that result will be set in any case. + + elsif Default /= Unknown + and then (Has_Size_Clause (Etype (Expr)) + or else + Has_Alignment_Clause (Etype (Expr))) + then + Set_Result (Unknown); + + -- If no indication found, set default + + else + Set_Result (Default); + end if; + + -- Return worst result found + + return Result; + end Has_Compatible_Alignment_Internal; + + -- Start of processing for Has_Compatible_Alignment + + begin + -- If Obj has no specified alignment, then set alignment from the type + -- alignment. Perhaps we should always do this, but for sure we should + -- do it when there is an address clause since we can do more if the + -- alignment is known. + + if Unknown_Alignment (Obj) then + Set_Alignment (Obj, Alignment (Etype (Obj))); + end if; + + -- Now do the internal call that does all the work + + return Has_Compatible_Alignment_Internal (Obj, Expr, Unknown); + end Has_Compatible_Alignment; + + ---------------------- + -- 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_Interfaces -- + -------------------- + + function Has_Interfaces + (T : Entity_Id; + Use_Full_View : Boolean := True) return Boolean + is + Typ : Entity_Id; + + begin + -- Handle concurrent types + + if Is_Concurrent_Type (T) then + Typ := Corresponding_Record_Type (T); + else + Typ := T; + end if; + + if not Present (Typ) + or else not Is_Record_Type (Typ) + or else not Is_Tagged_Type (Typ) + then + return False; + end if; + + -- Handle private types + + if Use_Full_View + and then Present (Full_View (Typ)) + then + Typ := Full_View (Typ); + end if; + + -- Handle concurrent record types + + if Is_Concurrent_Record_Type (Typ) + and then Is_Non_Empty_List (Abstract_Interface_List (Typ)) + then + return True; + end if; + + loop + if Is_Interface (Typ) + or else + (Is_Record_Type (Typ) + and then Present (Interfaces (Typ)) + and then not Is_Empty_Elmt_List (Interfaces (Typ))) + then + return True; + end if; + + exit when Etype (Typ) = Typ + + -- Handle private types + + or else (Present (Full_View (Etype (Typ))) + and then Full_View (Etype (Typ)) = Typ) + + -- Protect the frontend against wrong source with cyclic + -- derivations + + or else Etype (Typ) = T; + + -- Climb to the ancestor type handling private types + + if Present (Full_View (Etype (Typ))) then + Typ := Full_View (Etype (Typ)); + else + Typ := Etype (Typ); + end if; + end loop; + + return False; + end Has_Interfaces; + + ------------------------ + -- Has_Null_Exclusion -- + ------------------------ + + function Has_Null_Exclusion (N : Node_Id) return Boolean is + begin + case Nkind (N) is + when N_Access_Definition | + N_Access_Function_Definition | + N_Access_Procedure_Definition | + N_Access_To_Object_Definition | + N_Allocator | + N_Derived_Type_Definition | + N_Function_Specification | + N_Subtype_Declaration => + return Null_Exclusion_Present (N); + + when N_Component_Definition | + N_Formal_Object_Declaration | + N_Object_Renaming_Declaration => + if Present (Subtype_Mark (N)) then + return Null_Exclusion_Present (N); + else pragma Assert (Present (Access_Definition (N))); + return Null_Exclusion_Present (Access_Definition (N)); + end if; + + when N_Discriminant_Specification => + if Nkind (Discriminant_Type (N)) = N_Access_Definition then + return Null_Exclusion_Present (Discriminant_Type (N)); + else + return Null_Exclusion_Present (N); + end if; + + when N_Object_Declaration => + if Nkind (Object_Definition (N)) = N_Access_Definition then + return Null_Exclusion_Present (Object_Definition (N)); + else + return Null_Exclusion_Present (N); + end if; + + when N_Parameter_Specification => + if Nkind (Parameter_Type (N)) = N_Access_Definition then + return Null_Exclusion_Present (Parameter_Type (N)); + else + return Null_Exclusion_Present (N); + end if; + + when others => + return False; + + end case; + end Has_Null_Exclusion; + + ------------------------ + -- 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_Overriding_Initialize -- + ------------------------------- + + function Has_Overriding_Initialize (T : Entity_Id) return Boolean is + BT : constant Entity_Id := Base_Type (T); + Comp : Entity_Id; + P : Elmt_Id; + + begin + if Is_Controlled (BT) then + + -- For derived types, check immediate ancestor, excluding + -- Controlled itself. + + if Is_Derived_Type (BT) + and then not In_Predefined_Unit (Etype (BT)) + and then Has_Overriding_Initialize (Etype (BT)) + then + return True; + + elsif Present (Primitive_Operations (BT)) then + P := First_Elmt (Primitive_Operations (BT)); + while Present (P) loop + if Chars (Node (P)) = Name_Initialize + and then Comes_From_Source (Node (P)) + then + return True; + end if; + + Next_Elmt (P); + end loop; + end if; + + return False; + + elsif Has_Controlled_Component (BT) then + Comp := First_Component (BT); + while Present (Comp) loop + if Has_Overriding_Initialize (Etype (Comp)) then + return True; + end if; + + Next_Component (Comp); + end loop; + + return False; + + else + return False; + end if; + end Has_Overriding_Initialize; + + -------------------------------------- + -- Has_Preelaborable_Initialization -- + -------------------------------------- + + function Has_Preelaborable_Initialization (E : Entity_Id) return Boolean is + Has_PE : Boolean; + + procedure Check_Components (E : Entity_Id); + -- Check component/discriminant chain, sets Has_PE False if a component + -- or discriminant does not meet the preelaborable initialization rules. + + ---------------------- + -- Check_Components -- + ---------------------- + + procedure Check_Components (E : Entity_Id) is + Ent : Entity_Id; + Exp : Node_Id; + + function Is_Preelaborable_Expression (N : Node_Id) return Boolean; + -- Returns True if and only if the expression denoted by N does not + -- violate restrictions on preelaborable constructs (RM-10.2.1(5-9)). + + --------------------------------- + -- Is_Preelaborable_Expression -- + --------------------------------- + + function Is_Preelaborable_Expression (N : Node_Id) return Boolean is + Exp : Node_Id; + Assn : Node_Id; + Choice : Node_Id; + Comp_Type : Entity_Id; + Is_Array_Aggr : Boolean; + + begin + if Is_Static_Expression (N) then + return True; + + elsif Nkind (N) = N_Null then + return True; + + -- Attributes are allowed in general, even if their prefix is a + -- formal type. (It seems that certain attributes known not to be + -- static might not be allowed, but there are no rules to prevent + -- them.) + + elsif Nkind (N) = N_Attribute_Reference then + return True; + + -- The name of a discriminant evaluated within its parent type is + -- defined to be preelaborable (10.2.1(8)). Note that we test for + -- names that denote discriminals as well as discriminants to + -- catch references occurring within init procs. + + elsif Is_Entity_Name (N) + and then + (Ekind (Entity (N)) = E_Discriminant + or else + ((Ekind (Entity (N)) = E_Constant + or else Ekind (Entity (N)) = E_In_Parameter) + and then Present (Discriminal_Link (Entity (N))))) + then + return True; + + elsif Nkind (N) = N_Qualified_Expression then + return Is_Preelaborable_Expression (Expression (N)); + + -- For aggregates we have to check that each of the associations + -- is preelaborable. + + elsif Nkind (N) = N_Aggregate + or else Nkind (N) = N_Extension_Aggregate + then + Is_Array_Aggr := Is_Array_Type (Etype (N)); + + if Is_Array_Aggr then + Comp_Type := Component_Type (Etype (N)); + end if; + + -- Check the ancestor part of extension aggregates, which must + -- be either the name of a type that has preelaborable init or + -- an expression that is preelaborable. + + if Nkind (N) = N_Extension_Aggregate then + declare + Anc_Part : constant Node_Id := Ancestor_Part (N); + + begin + if Is_Entity_Name (Anc_Part) + and then Is_Type (Entity (Anc_Part)) + then + if not Has_Preelaborable_Initialization + (Entity (Anc_Part)) + then + return False; + end if; + + elsif not Is_Preelaborable_Expression (Anc_Part) then + return False; + end if; + end; + end if; + + -- Check positional associations + + Exp := First (Expressions (N)); + while Present (Exp) loop + if not Is_Preelaborable_Expression (Exp) then + return False; + end if; + + Next (Exp); + end loop; + + -- Check named associations + + Assn := First (Component_Associations (N)); + while Present (Assn) loop + Choice := First (Choices (Assn)); + while Present (Choice) loop + if Is_Array_Aggr then + if Nkind (Choice) = N_Others_Choice then + null; + + elsif Nkind (Choice) = N_Range then + if not Is_Static_Range (Choice) then + return False; + end if; + + elsif not Is_Static_Expression (Choice) then + return False; + end if; + + else + Comp_Type := Etype (Choice); + end if; + + Next (Choice); + end loop; + + -- If the association has a <> at this point, then we have + -- to check whether the component's type has preelaborable + -- initialization. Note that this only occurs when the + -- association's corresponding component does not have a + -- default expression, the latter case having already been + -- expanded as an expression for the association. + + if Box_Present (Assn) then + if not Has_Preelaborable_Initialization (Comp_Type) then + return False; + end if; + + -- In the expression case we check whether the expression + -- is preelaborable. + + elsif + not Is_Preelaborable_Expression (Expression (Assn)) + then + return False; + end if; + + Next (Assn); + end loop; + + -- If we get here then aggregate as a whole is preelaborable + + return True; + + -- All other cases are not preelaborable + + else + return False; + end if; + end Is_Preelaborable_Expression; + + -- Start of processing for Check_Components + + begin + -- Loop through entities of record or protected type + + Ent := E; + while Present (Ent) loop + + -- We are interested only in components and discriminants + + if Ekind (Ent) = E_Component + or else + Ekind (Ent) = E_Discriminant + then + -- Get default expression if any. If there is no declaration + -- node, it means we have an internal entity. The parent and + -- tag fields are examples of such entities. For these cases, + -- we just test the type of the entity. + + if Present (Declaration_Node (Ent)) then + Exp := Expression (Declaration_Node (Ent)); + else + Exp := Empty; + end if; + + -- A component has PI if it has no default expression and the + -- component type has PI. + + if No (Exp) then + if not Has_Preelaborable_Initialization (Etype (Ent)) then + Has_PE := False; + exit; + end if; + + -- Require the default expression to be preelaborable + + elsif not Is_Preelaborable_Expression (Exp) then + Has_PE := False; + exit; + end if; + end if; + + Next_Entity (Ent); + end loop; + end Check_Components; + + -- Start of processing for Has_Preelaborable_Initialization + + begin + -- Immediate return if already marked as known preelaborable init. This + -- covers types for which this function has already been called once + -- and returned True (in which case the result is cached), and also + -- types to which a pragma Preelaborable_Initialization applies. + + if Known_To_Have_Preelab_Init (E) then + return True; + end if; + + -- If the type is a subtype representing a generic actual type, then + -- test whether its base type has preelaborable initialization since + -- the subtype representing the actual does not inherit this attribute + -- from the actual or formal. (but maybe it should???) + + if Is_Generic_Actual_Type (E) then + return Has_Preelaborable_Initialization (Base_Type (E)); + end if; + + -- All elementary types have preelaborable initialization + + if Is_Elementary_Type (E) then + Has_PE := True; + + -- Array types have PI if the component type has PI + + elsif Is_Array_Type (E) then + Has_PE := Has_Preelaborable_Initialization (Component_Type (E)); + + -- A derived type has preelaborable initialization if its parent type + -- has preelaborable initialization and (in the case of a derived record + -- extension) if the non-inherited components all have preelaborable + -- initialization. However, a user-defined controlled type with an + -- overriding Initialize procedure does not have preelaborable + -- initialization. + + elsif Is_Derived_Type (E) then + + -- If the derived type is a private extension then it doesn't have + -- preelaborable initialization. + + if Ekind (Base_Type (E)) = E_Record_Type_With_Private then + return False; + end if; + + -- First check whether ancestor type has preelaborable initialization + + Has_PE := Has_Preelaborable_Initialization (Etype (Base_Type (E))); + + -- If OK, check extension components (if any) + + if Has_PE and then Is_Record_Type (E) then + Check_Components (First_Entity (E)); + end if; + + -- Check specifically for 10.2.1(11.4/2) exception: a controlled type + -- with a user defined Initialize procedure does not have PI. + + if Has_PE + and then Is_Controlled (E) + and then Has_Overriding_Initialize (E) + then + Has_PE := False; + end if; + + -- Private types not derived from a type having preelaborable init and + -- that are not marked with pragma Preelaborable_Initialization do not + -- have preelaborable initialization. + + elsif Is_Private_Type (E) then + return False; + + -- Record type has PI if it is non private and all components have PI + + elsif Is_Record_Type (E) then + Has_PE := True; + Check_Components (First_Entity (E)); + + -- Protected types must not have entries, and components must meet + -- same set of rules as for record components. + + elsif Is_Protected_Type (E) then + if Has_Entries (E) then + Has_PE := False; + else + Has_PE := True; + Check_Components (First_Entity (E)); + Check_Components (First_Private_Entity (E)); + end if; + + -- Type System.Address always has preelaborable initialization + + elsif Is_RTE (E, RE_Address) then + Has_PE := True; + + -- In all other cases, type does not have preelaborable initialization + + else + return False; + end if; + + -- If type has preelaborable initialization, cache result + + if Has_PE then + Set_Known_To_Have_Preelab_Init (E); + end if; + + return Has_PE; + end Has_Preelaborable_Initialization; + + --------------------------- + -- 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; + + -------------------------- + -- Implements_Interface -- + -------------------------- + + function Implements_Interface + (Typ_Ent : Entity_Id; + Iface_Ent : Entity_Id; + Exclude_Parents : Boolean := False) return Boolean + is + Ifaces_List : Elist_Id; + Elmt : Elmt_Id; + Iface : Entity_Id; + Typ : Entity_Id; + + begin + if Is_Class_Wide_Type (Typ_Ent) then + Typ := Etype (Typ_Ent); + else + Typ := Typ_Ent; + end if; + + if Is_Class_Wide_Type (Iface_Ent) then + Iface := Etype (Iface_Ent); + else + Iface := Iface_Ent; + end if; + + if not Has_Interfaces (Typ) then + return False; + end if; + + Collect_Interfaces (Typ, Ifaces_List); + + Elmt := First_Elmt (Ifaces_List); + while Present (Elmt) loop + if Is_Ancestor (Node (Elmt), Typ) + and then Exclude_Parents + then + null; + + elsif Node (Elmt) = Iface then + return True; + end if; + + Next_Elmt (Elmt); + end loop; + + return False; + end Implements_Interface; + + ----------------- + -- In_Instance -- + ----------------- + + function In_Instance return Boolean is + Curr_Unit : constant Entity_Id := Cunit_Entity (Current_Sem_Unit); + S : Entity_Id; + + begin + S := Current_Scope; + 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 + -- A child instance is always compiled in the context of a parent + -- instance. Nevertheless, the actuals are not analyzed in an + -- instance context. We detect this case by examining the current + -- compilation unit, which must be a child instance, and checking + -- that it is not currently on the scope stack. + + if Is_Child_Unit (Curr_Unit) + and then + Nkind (Unit (Cunit (Current_Sem_Unit))) + = N_Package_Instantiation + and then not In_Open_Scopes (Curr_Unit) + then + return False; + else + return True; + end if; + 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; + + begin + S := Current_Scope; + 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; + + begin + S := Current_Scope; + 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; + + begin + S := Current_Scope; + 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_Package_Body -- + --------------------- + + function In_Package_Body return Boolean is + S : Entity_Id; + + begin + S := Current_Scope; + 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_Parameter_Specification -- + -------------------------------- + + function In_Parameter_Specification (N : Node_Id) return Boolean is + PN : Node_Id; + + begin + PN := Parent (N); + while Present (PN) loop + if Nkind (PN) = N_Parameter_Specification then + return True; + end if; + + PN := Parent (PN); + end loop; + + return False; + end In_Parameter_Specification; + + -------------------------------------- + -- 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; + + ------------------------------------------ + -- Inspect_Deferred_Constant_Completion -- + ------------------------------------------ + + procedure Inspect_Deferred_Constant_Completion (Decls : List_Id) is + Decl : Node_Id; + + begin + Decl := First (Decls); + while Present (Decl) loop + + -- Deferred constant signature + + if Nkind (Decl) = N_Object_Declaration + and then Constant_Present (Decl) + and then No (Expression (Decl)) + + -- No need to check internally generated constants + + and then Comes_From_Source (Decl) + + -- The constant is not completed. A full object declaration + -- or a pragma Import complete a deferred constant. + + and then not Has_Completion (Defining_Identifier (Decl)) + then + Error_Msg_N + ("constant declaration requires initialization expression", + Defining_Identifier (Decl)); + end if; + + Decl := Next (Decl); + end loop; + end Inspect_Deferred_Constant_Completion; + + ------------------- + -- Is_AAMP_Float -- + ------------------- + + function Is_AAMP_Float (E : Entity_Id) return Boolean is + pragma Assert (Is_Type (E)); + begin + 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 (Is_Concurrent_Type (E) + and then In_Open_Scopes (E)) + + -- Current instance of type, either directly or as rewritten + -- reference to the current object. + + or else (Is_Entity_Name (Original_Node (Obj)) + and then Present (Entity (Original_Node (Obj))) + and then Is_Type (Entity (Original_Node (Obj)))) + + 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 + + ---------------------- + -- Is_Atomic_Prefix -- + ---------------------- + + 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; + + ---------------------------------- + -- Object_Has_Atomic_Components -- + ---------------------------------- + + 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_Coextension_Root -- + ------------------------- + + function Is_Coextension_Root (N : Node_Id) return Boolean is + begin + return + Nkind (N) = N_Allocator + and then Present (Coextensions (N)) + + -- Anonymous access discriminants carry a list of all nested + -- controlled coextensions. + + and then not Is_Dynamic_Coextension (N) + and then not Is_Static_Coextension (N); + end Is_Coextension_Root; + + ----------------------------- + -- Is_Concurrent_Interface -- + ----------------------------- + + function Is_Concurrent_Interface (T : Entity_Id) return Boolean is + begin + return + Is_Interface (T) + and then + (Is_Protected_Interface (T) + or else Is_Synchronized_Interface (T) + or else Is_Task_Interface (T)); + end Is_Concurrent_Interface; + + -------------------------------------- + -- 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): Always assume the object could be mutable in + -- the dereferenced case, since the access value might denote an + -- unconstrained aliased object, whereas in Ada 95 the designated + -- object is guaranteed to be constrained. A worst-case assumption + -- has to apply in Ada 2005 because we can't tell at compile time + -- whether the object is "constrained by its initial value" + -- (despite the fact that 3.10.2(26/2) and 8.5.1(5/2) are + -- semantic rules -- these rules are acknowledged to need fixing). + + if Ada_Version < Ada_05 then + if Is_Access_Type (Prefix_Type) + or else Nkind (P) = N_Explicit_Dereference + then + return False; + end if; + + elsif Ada_Version >= Ada_05 then + if Is_Access_Type (Prefix_Type) then + + -- If the access type is pool-specific, and there is no + -- constrained partial view of the designated type, then the + -- designated object is known to be constrained. + + if Ekind (Prefix_Type) = E_Access_Type + and then not Has_Constrained_Partial_View + (Designated_Type (Prefix_Type)) + then + return False; + + -- Otherwise (general access type, or there is a constrained + -- partial view of the designated type), we need to check + -- based on the designated type. + + else + Prefix_Type := Designated_Type (Prefix_Type); + end if; + end if; + 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. + + -- Ada 2005 (AI-363): In Ada 2005 an aliased object can be mutable + + 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 or else Ada_Version >= Ada_05) + 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; + end Is_Descendent_Of; + + -------------- + -- 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) or else Etype (Indx_Typ) = Any_Type 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)) + + -- Special VM case for tag components, which need to be + -- defined in this case, but are never initialized as VMs + -- are using other dispatching mechanisms. Ignore this + -- uninitialized case. Note that this applies both to the + -- uTag entry and the main vtable pointer (CPP_Class case). + + and then (VM_Target = No_VM or else not Is_Tag (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; + pragma Warnings (Off, Report_Errors); + + 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 properly handles + -- 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_Object_Reference -- + ------------------------- + + function Is_Object_Reference (N : Node_Id) return Boolean is + begin + if Is_Entity_Name (N) then + return Present (Entity (N)) and then 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, Sure => True); + + -- 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), Sure => True); + 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 corresponding 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_Protected_Self_Reference -- + --------------------------------- + + function Is_Protected_Self_Reference (N : Node_Id) return Boolean + is + function In_Access_Definition (N : Node_Id) return Boolean; + -- Returns true if N belongs to an access definition + + -------------------------- + -- In_Access_Definition -- + -------------------------- + + function In_Access_Definition (N : Node_Id) return Boolean + is + P : Node_Id := Parent (N); + begin + while Present (P) loop + if Nkind (P) = N_Access_Definition then + return True; + end if; + P := Parent (P); + end loop; + return False; + end In_Access_Definition; + + -- Start of processing for Is_Protected_Self_Reference + + begin + return Ada_Version >= Ada_05 + and then Is_Entity_Name (N) + and then Is_Protected_Type (Entity (N)) + and then In_Open_Scopes (Entity (N)) + and then not In_Access_Definition (N); + end Is_Protected_Self_Reference; + + ----------------------------- + -- 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 + begin + -- A remote access to class-wide type is a general access to object type + -- declared in the visible part of a Remote_Types or Remote_Call_ + -- Interface unit. + + return Ekind (E) = E_General_Access_Type + and then (Is_Remote_Call_Interface (E) or else Is_Remote_Types (E)); + 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_Synchronized_Tagged_Type -- + --------------------------------- + + function Is_Synchronized_Tagged_Type (E : Entity_Id) return Boolean is + Kind : constant Entity_Kind := Ekind (Base_Type (E)); + + begin + -- A task or protected type derived from an interface is a tagged type. + -- Such a tagged type is called a synchronized tagged type, as are + -- synchronized interfaces and private extensions whose declaration + -- includes the reserved word synchronized. + + return (Is_Tagged_Type (E) + and then (Kind = E_Task_Type + or else Kind = E_Protected_Type)) + or else + (Is_Interface (E) + and then Is_Synchronized_Interface (E)) + or else + (Ekind (E) = E_Record_Type_With_Private + and then (Synchronized_Present (Parent (E)) + or else Is_Synchronized_Interface (Etype (E)))); + end Is_Synchronized_Tagged_Type; + + ----------------- + -- Is_Transfer -- + ----------------- + + function Is_Transfer (N : Node_Id) return Boolean is + Kind : constant Node_Kind := Nkind (N); + + begin + if Kind = N_Simple_Return_Statement + or else + Kind = N_Extended_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_Value_Type -- + ------------------- + + function Is_Value_Type (T : Entity_Id) return Boolean is + begin + return VM_Target = CLI_Target + and then Chars (T) /= No_Name + and then Get_Name_String (Chars (T)) = "valuetype"; + end Is_Value_Type; + + ----------------- + -- 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). + + -- In Ada 2005 we have a further case to consider: the prefix may be + -- a function call given in prefix notation. The original node appears + -- to be a selected component, but we need to examine the call. + + elsif Nkind (N) = N_Explicit_Dereference + and then Nkind (Orig_Node) /= N_Explicit_Dereference + and then Present (Etype (Orig_Node)) + and then Is_Access_Type (Etype (Orig_Node)) + then + return Is_Variable_Prefix (Original_Node (Prefix (N))) + or else + (Nkind (Orig_Node) = N_Function_Call + and then not Is_Access_Constant (Etype (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) + and then Present (Entity (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; + Last_Assignment_Only : Boolean := False) + is + begin + if Is_Assignable (Ent) then + Set_Last_Assignment (Ent, Empty); + end if; + + if not Last_Assignment_Only and then 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 (Last_Assignment_Only : Boolean := False) 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, Last_Assignment_Only); + 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 + + if not Last_Assignment_Only then + Kill_All_Checks; + end if; + + -- 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 Is_Package_Or_Generic_Package (S) + or else Is_Concurrent_Type (S) + then + Kill_Current_Values_For_Entity_Chain (First_Private_Entity (S)); + end if; + + -- If this is a not a subprogram, deal with parents + + if not Is_Subprogram (S) then + S := Scope (S); + exit Scope_Loop when S = Standard_Standard; + 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; + + -------------------------- + -- Known_To_Be_Assigned -- + -------------------------- + + function Known_To_Be_Assigned (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); + + -- Function call arguments are never lvalues + + when N_Function_Call => + return False; + + -- Positional parameter for procedure or accept call + + when N_Procedure_Call_Statement | + N_Accept_Statement + => + declare + Proc : Entity_Id; + Form : Entity_Id; + Act : Node_Id; + + begin + Proc := Get_Subprogram_Entity (P); + + if No (Proc) then + return False; + end if; + + -- If we are not a list member, something is strange, so + -- be conservative and return False. + + if not Is_List_Member (N) then + return False; + end if; + + -- We are going to find the right formal by stepping forward + -- through the formals, as we step backwards in the actuals. + + Form := First_Formal (Proc); + Act := N; + loop + -- If no formal, something is weird, so be conservative + -- and return False. + + if No (Form) then + return False; + end if; + + Prev (Act); + exit when No (Act); + Next_Formal (Form); + end loop; + + return Ekind (Form) /= E_In_Parameter; + end; + + -- Named parameter for procedure or accept call + + when N_Parameter_Association => + declare + Proc : Entity_Id; + Form : Entity_Id; + + begin + Proc := Get_Subprogram_Entity (Parent (P)); + + if No (Proc) then + return False; + end if; + + -- Loop through formals to find the one that matches + + Form := First_Formal (Proc); + loop + -- If no matching formal, that's peculiar, some kind of + -- previous error, so return False to be conservative. + + if No (Form) then + return False; + end if; + + -- Else test for match + + if Chars (Form) = Chars (Selector_Name (P)) then + return Ekind (Form) /= E_In_Parameter; + end if; + + Next_Formal (Form); + end loop; + end; + + -- Test for appearing in a conversion that itself appears + -- in an lvalue context, since this should be an lvalue. + + when N_Type_Conversion => + return Known_To_Be_Assigned (P); + + -- All other references are definitely not known to be modifications + + when others => + return False; + + end case; + end Known_To_Be_Assigned; + + ------------------- + -- May_Be_Lvalue -- + ------------------- + + function May_Be_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 => + return N = Prefix (P) + and then Name_Implies_Lvalue_Prefix (Attribute_Name (P)); + + when N_Expanded_Name | + N_Explicit_Dereference | + N_Indexed_Component | + N_Reference | + N_Selected_Component | + N_Slice => + return N = Prefix (P); + + -- Function call arguments are never lvalues + + when N_Function_Call => + return False; + + -- Positional parameter for procedure, entry, or accept call + + when N_Procedure_Call_Statement | + N_Entry_Call_Statement | + N_Accept_Statement + => + declare + Proc : Entity_Id; + Form : Entity_Id; + Act : Node_Id; + + begin + Proc := Get_Subprogram_Entity (P); + + if No (Proc) then + return True; + end if; + + -- If we are not a list member, something is strange, so + -- be conservative and return True. + + if not Is_List_Member (N) then + return True; + end if; + + -- We are going to find the right formal by stepping forward + -- through the formals, as we step backwards in the actuals. + + Form := First_Formal (Proc); + Act := N; + loop + -- If no formal, something is weird, so be conservative + -- and return True. + + if No (Form) then + return True; + end if; + + Prev (Act); + exit when No (Act); + Next_Formal (Form); + end loop; + + return Ekind (Form) /= E_In_Parameter; + end; + + -- Named parameter for procedure or accept call + + when N_Parameter_Association => + declare + Proc : Entity_Id; + Form : Entity_Id; + + begin + Proc := Get_Subprogram_Entity (Parent (P)); + + if No (Proc) then + return True; + end if; + + -- Loop through formals to find the one that matches + + Form := First_Formal (Proc); + loop + -- If no matching formal, that's peculiar, some kind of + -- previous error, so return True to be conservative. + + if No (Form) then + return True; + end if; + + -- Else test for match + + if Chars (Form) = Chars (Selector_Name (P)) then + return Ekind (Form) /= E_In_Parameter; + end if; + + Next_Formal (Form); + end loop; + end; + + -- Test for appearing in a conversion that itself appears in an + -- lvalue context, since this should be an lvalue. + + when N_Type_Conversion => + return May_Be_Lvalue (P); + + -- Test for appearance 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 May_Be_Lvalue; + + ----------------------- + -- Mark_Coextensions -- + ----------------------- + + procedure Mark_Coextensions (Context_Nod : Node_Id; Root_Nod : Node_Id) is + Is_Dynamic : Boolean; + -- Indicates whether the context causes nested coextensions to be + -- dynamic or static + + function Mark_Allocator (N : Node_Id) return Traverse_Result; + -- Recognize an allocator node and label it as a dynamic coextension + + -------------------- + -- Mark_Allocator -- + -------------------- + + function Mark_Allocator (N : Node_Id) return Traverse_Result is + begin + if Nkind (N) = N_Allocator then + if Is_Dynamic then + Set_Is_Dynamic_Coextension (N); + else + Set_Is_Static_Coextension (N); + end if; + end if; + + return OK; + end Mark_Allocator; + + procedure Mark_Allocators is new Traverse_Proc (Mark_Allocator); + + -- Start of processing Mark_Coextensions + + begin + case Nkind (Context_Nod) is + when N_Assignment_Statement | + N_Simple_Return_Statement => + Is_Dynamic := Nkind (Expression (Context_Nod)) = N_Allocator; + + when N_Object_Declaration => + Is_Dynamic := Nkind (Root_Nod) = N_Allocator; + + -- This routine should not be called for constructs which may not + -- contain coextensions. + + when others => + raise Program_Error; + end case; + + Mark_Allocators (Root_Nod); + end Mark_Coextensions; + + ---------------------- + -- Needs_One_Actual -- + ---------------------- + + function Needs_One_Actual (E : Entity_Id) return Boolean is + Formal : Entity_Id; + + begin + if Ada_Version >= Ada_05 + and then Present (First_Formal (E)) + then + Formal := Next_Formal (First_Formal (E)); + while Present (Formal) loop + if No (Default_Value (Formal)) then + return False; + end if; + + Next_Formal (Formal); + end loop; + + return True; + + else + return False; + end if; + end Needs_One_Actual; + + ------------------------- + -- 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, then + -- 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; Sure : Boolean) 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 + if Has_Pragma_Unmodified (Ent) then + Error_Msg_NE ("?pragma Unmodified given for &!", N, Ent); + end if; + + 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; + + Check_Nested_Access (Ent); + end if; + + Kill_Checks (Ent); + + -- If we are sure this is a modification from source, and we know + -- this modifies a constant, then give an appropriate warning. + + if Overlays_Constant (Ent) + and then Modification_Comes_From_Source + and then Sure + then + declare + A : constant Node_Id := Address_Clause (Ent); + begin + if Present (A) then + declare + Exp : constant Node_Id := Expression (A); + begin + if Nkind (Exp) = N_Attribute_Reference + and then Attribute_Name (Exp) = Name_Address + and then Is_Entity_Name (Prefix (Exp)) + then + Error_Msg_Sloc := Sloc (A); + Error_Msg_NE + ("constant& may be modified via address clause#?", + N, Entity (Prefix (Exp))); + end if; + end; + end if; + end; + end if; + + 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)). + + function Reference_To (Obj : Node_Id) return Node_Id; + -- An explicit dereference is created when removing side-effects from + -- expressions for constraint checking purposes. In this case a local + -- access type is created for it. The correct access level is that of + -- the original source node. We detect this case by noting that the + -- prefix of the dereference is created by an object declaration whose + -- initial expression is a reference. + + ------------------ + -- Reference_To -- + ------------------ + + function Reference_To (Obj : Node_Id) return Node_Id is + Pref : constant Node_Id := Prefix (Obj); + begin + if Is_Entity_Name (Pref) + and then Nkind (Parent (Entity (Pref))) = N_Object_Declaration + and then Present (Expression (Parent (Entity (Pref)))) + and then Nkind (Expression (Parent (Entity (Pref)))) = N_Reference + then + return (Prefix (Expression (Parent (Entity (Pref))))); + else + return Empty; + end if; + end Reference_To; + + -- Start of processing for Object_Access_Level + + begin + if Is_Entity_Name (Obj) then + E := Entity (Obj); + + if Is_Prival (E) then + E := Prival_Link (E); + end if; + + -- 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)); + + elsif not (Comes_From_Source (Obj)) then + declare + Ref : constant Node_Id := Reference_To (Obj); + begin + if Present (Ref) then + return Object_Access_Level (Ref); + else + return Type_Access_Level (Etype (Prefix (Obj))); + end if; + end; + + 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 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; + + --------------------------- + -- Primitive_Names_Match -- + --------------------------- + + function Primitive_Names_Match (E1, E2 : Entity_Id) return Boolean is + + function Non_Internal_Name (E : Entity_Id) return Name_Id; + -- Given an internal name, returns the corresponding non-internal name + + ------------------------ + -- Non_Internal_Name -- + ------------------------ + + function Non_Internal_Name (E : Entity_Id) return Name_Id is + begin + Get_Name_String (Chars (E)); + Name_Len := Name_Len - 1; + return Name_Find; + end Non_Internal_Name; + + -- Start of processing for Primitive_Names_Match + + begin + pragma Assert (Present (E1) and then Present (E2)); + + return Chars (E1) = Chars (E2) + or else + (not Is_Internal_Name (Chars (E1)) + and then Is_Internal_Name (Chars (E2)) + and then Non_Internal_Name (E2) = Chars (E1)) + or else + (not Is_Internal_Name (Chars (E2)) + and then Is_Internal_Name (Chars (E1)) + and then Non_Internal_Name (E1) = Chars (E2)) + or else + (Is_Predefined_Dispatching_Operation (E1) + and then Is_Predefined_Dispatching_Operation (E2) + and then Same_TSS (E1, E2)) + or else + (Is_Init_Proc (E1) and then Is_Init_Proc (E2)); + end Primitive_Names_Match; + + ----------------------- + -- Process_End_Label -- + ----------------------- + + procedure Process_End_Label + (N : Node_Id; + Typ : Character; + Ent : Entity_Id) + is + Loc : Source_Ptr; + Nam : Node_Id; + Scop : Entity_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; E : Entity_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. E is the corresponding entity. + + ------------------------- + -- Generate_Parent_Ref -- + ------------------------- + + procedure Generate_Parent_Ref (N : Node_Id; E : Entity_Id) is + begin + -- If names do not match, something weird, skip reference + + if Chars (E) = Chars (N) then + + -- Generate the reference. We do NOT consider this as a reference + -- for unreferenced symbol purposes. + + Generate_Reference (E, N, 'r', Set_Ref => False, Force => True); + + if Style_Check then + Style.Check_Identifier (N, E); + end if; + end if; + 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) We climb the + -- scope stack to find the expected entities. + + if Comes_From_Source (Endl) then + Nam := Name (Endl); + Scop := Current_Scope; + while Nkind (Nam) = N_Selected_Component loop + Scop := Scope (Scop); + exit when No (Scop); + Generate_Parent_Ref (Selector_Name (Nam), Scop); + Nam := Prefix (Nam); + end loop; + + if Present (Scop) then + Generate_Parent_Ref (Nam, Scope (Scop)); + end if; + 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; + + -------------------- + -- Remove_Homonym -- + -------------------- + + procedure Remove_Homonym (E : Entity_Id) is + Prev : Entity_Id := Empty; + H : Entity_Id; + + begin + if E = Current_Entity (E) then + if Present (Homonym (E)) then + Set_Current_Entity (Homonym (E)); + else + Set_Name_Entity_Id (Chars (E), Empty); + end if; + else + H := Current_Entity (E); + while Present (H) and then H /= E loop + Prev := H; + H := Homonym (H); + end loop; + + Set_Homonym (Prev, Homonym (E)); + end if; + end Remove_Homonym; + + --------------------- + -- 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 not Is_Value_Type (Typ); + + -- Record type + + elsif Is_Record_Type (Typ) then + 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; + + -- 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 + -- reanalyze 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; + + procedure Reset_Analyzed is new Traverse_Proc (Clear_Analyzed); + + -- Start of processing for Reset_Analyzed_Flags + + begin + Reset_Analyzed (N); + end Reset_Analyzed_Flags; + + --------------------------- + -- Safe_To_Capture_Value -- + --------------------------- + + function Safe_To_Capture_Value + (N : Node_Id; + Ent : Entity_Id; + Cond : Boolean := False) return Boolean + is + begin + -- The only entities for which we track constant values are variables + -- which are not renamings, constants, out parameters, and in out + -- parameters, so check if we have this case. + + -- Note: it may seem odd to track constant values for constants, but in + -- fact this routine is used for other purposes than simply capturing + -- the value. In particular, the setting of Known[_Non]_Null. + + if (Ekind (Ent) = E_Variable and then No (Renamed_Object (Ent))) + or else + Ekind (Ent) = E_Constant + or else + Ekind (Ent) = E_Out_Parameter + or else + Ekind (Ent) = E_In_Out_Parameter + then + null; + + -- For conditionals, we also allow loop parameters and all formals, + -- including in parameters. + + elsif Cond + and then + (Ekind (Ent) = E_Loop_Parameter + or else + Ekind (Ent) = E_In_Parameter) + then + null; + + -- For all other cases, not just unsafe, but impossible to capture + -- Current_Value, since the above are the only entities which have + -- Current_Value fields. + + else + return False; + end if; + + -- Skip if volatile or aliased, 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, or whose address is taken. Also + -- never capture value of library level variables (an attempt to do so + -- can occur in the case of package elaboration code). + + if Treat_As_Volatile (Ent) + or else Is_Aliased (Ent) + or else Present (Address_Clause (Ent)) + or else Address_Taken (Ent) + or else (Is_Library_Level_Entity (Ent) + and then Ekind (Ent) = E_Variable) + 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 and loops. + + 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 + and then + Ekind (R_Scope) /= E_Loop + 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). We skip this if Cond is True, since the + -- capturing of values from conditional tests handles this ok. + + if Cond then + return True; + end if; + + 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_Object -- + ----------------- + + function Same_Object (Node1, Node2 : Node_Id) return Boolean is + N1 : constant Node_Id := Original_Node (Node1); + N2 : constant Node_Id := Original_Node (Node2); + -- We do the tests on original nodes, since we are most interested + -- in the original source, not any expansion that got in the way. + + K1 : constant Node_Kind := Nkind (N1); + K2 : constant Node_Kind := Nkind (N2); + + begin + -- First case, both are entities with same entity + + if K1 in N_Has_Entity + and then K2 in N_Has_Entity + and then Present (Entity (N1)) + and then Present (Entity (N2)) + and then (Ekind (Entity (N1)) = E_Variable + or else + Ekind (Entity (N1)) = E_Constant) + and then Entity (N1) = Entity (N2) + then + return True; + + -- Second case, selected component with same selector, same record + + elsif K1 = N_Selected_Component + and then K2 = N_Selected_Component + and then Chars (Selector_Name (N1)) = Chars (Selector_Name (N2)) + then + return Same_Object (Prefix (N1), Prefix (N2)); + + -- Third case, indexed component with same subscripts, same array + + elsif K1 = N_Indexed_Component + and then K2 = N_Indexed_Component + and then Same_Object (Prefix (N1), Prefix (N2)) + then + declare + E1, E2 : Node_Id; + begin + E1 := First (Expressions (N1)); + E2 := First (Expressions (N2)); + while Present (E1) loop + if not Same_Value (E1, E2) then + return False; + else + Next (E1); + Next (E2); + end if; + end loop; + + return True; + end; + + -- Fourth case, slice of same array with same bounds + + elsif K1 = N_Slice + and then K2 = N_Slice + and then Nkind (Discrete_Range (N1)) = N_Range + and then Nkind (Discrete_Range (N2)) = N_Range + and then Same_Value (Low_Bound (Discrete_Range (N1)), + Low_Bound (Discrete_Range (N2))) + and then Same_Value (High_Bound (Discrete_Range (N1)), + High_Bound (Discrete_Range (N2))) + then + return Same_Name (Prefix (N1), Prefix (N2)); + + -- All other cases, not clearly the same object + + else + return False; + end if; + end Same_Object; + + --------------- + -- 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; + + ---------------- + -- Same_Value -- + ---------------- + + function Same_Value (Node1, Node2 : Node_Id) return Boolean is + begin + if Compile_Time_Known_Value (Node1) + and then Compile_Time_Known_Value (Node2) + and then Expr_Value (Node1) = Expr_Value (Node2) + then + return True; + elsif Same_Object (Node1, Node2) then + return True; + else + return False; + end if; + end Same_Value; + + ------------------------ + -- 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_Convention -- + -------------------- + + procedure Set_Convention (E : Entity_Id; Val : Snames.Convention_Id) is + begin + Basic_Set_Convention (E, Val); + + if Is_Type (E) + and then Is_Access_Subprogram_Type (Base_Type (E)) + and then Has_Foreign_Convention (E) + then + Set_Can_Use_Internal_Rep (E, False); + end if; + end Set_Convention; + + ------------------------ + -- 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_Debug_Info_Needed -- + --------------------------- + + procedure Set_Debug_Info_Needed (T : Entity_Id) is + + procedure Set_Debug_Info_Needed_If_Not_Set (E : Entity_Id); + pragma Inline (Set_Debug_Info_Needed_If_Not_Set); + -- Used to set debug info in a related node if not set already + + -------------------------------------- + -- Set_Debug_Info_Needed_If_Not_Set -- + -------------------------------------- + + procedure Set_Debug_Info_Needed_If_Not_Set (E : Entity_Id) is + begin + if Present (E) + and then not Needs_Debug_Info (E) + then + Set_Debug_Info_Needed (E); + + -- For a private type, indicate that the full view also needs + -- debug information. + + if Is_Type (E) + and then Is_Private_Type (E) + and then Present (Full_View (E)) + then + Set_Debug_Info_Needed (Full_View (E)); + end if; + end if; + end Set_Debug_Info_Needed_If_Not_Set; + + -- Start of processing for Set_Debug_Info_Needed + + begin + -- Nothing to do if argument is Empty or has Debug_Info_Off set, which + -- indicates that Debug_Info_Needed is never required for the entity. + + if No (T) + or else Debug_Info_Off (T) + then + return; + end if; + + -- Set flag in entity itself. Note that we will go through the following + -- circuitry even if the flag is already set on T. That's intentional, + -- it makes sure that the flag will be set in subsidiary entities. + + Set_Needs_Debug_Info (T); + + -- Set flag on subsidiary entities if not set already + + if Is_Object (T) then + Set_Debug_Info_Needed_If_Not_Set (Etype (T)); + + elsif Is_Type (T) then + Set_Debug_Info_Needed_If_Not_Set (Etype (T)); + + if Is_Record_Type (T) then + declare + Ent : Entity_Id := First_Entity (T); + begin + while Present (Ent) loop + Set_Debug_Info_Needed_If_Not_Set (Ent); + Next_Entity (Ent); + end loop; + end; + + elsif Is_Array_Type (T) then + Set_Debug_Info_Needed_If_Not_Set (Component_Type (T)); + + declare + Indx : Node_Id := First_Index (T); + begin + while Present (Indx) loop + Set_Debug_Info_Needed_If_Not_Set (Etype (Indx)); + Indx := Next_Index (Indx); + end loop; + end; + + if Is_Packed (T) then + Set_Debug_Info_Needed_If_Not_Set (Packed_Array_Type (T)); + end if; + + elsif Is_Access_Type (T) then + Set_Debug_Info_Needed_If_Not_Set (Directly_Designated_Type (T)); + + elsif Is_Private_Type (T) then + Set_Debug_Info_Needed_If_Not_Set (Full_View (T)); + + elsif Is_Protected_Type (T) then + Set_Debug_Info_Needed_If_Not_Set (Corresponding_Record_Type (T)); + end if; + end if; + end Set_Debug_Info_Needed; + + --------------------------------- + -- 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_Optimize_Alignment_Flags -- + ---------------------------------- + + procedure Set_Optimize_Alignment_Flags (E : Entity_Id) is + begin + if Optimize_Alignment = 'S' then + Set_Optimize_Alignment_Space (E); + elsif Optimize_Alignment = 'T' then + Set_Optimize_Alignment_Time (E); + end if; + end Set_Optimize_Alignment_Flags; + + ----------------------- + -- Set_Public_Status -- + ----------------------- + + procedure Set_Public_Status (Id : Entity_Id) is + S : constant Entity_Id := Current_Scope; + + function Within_HSS_Or_If (E : Entity_Id) return Boolean; + -- Determines if E is defined within handled statement sequence or + -- an if statement, returns True if so, False otherwise. + + ---------------------- + -- Within_HSS_Or_If -- + ---------------------- + + function Within_HSS_Or_If (E : Entity_Id) return Boolean is + N : Node_Id; + begin + N := Declaration_Node (E); + loop + N := Parent (N); + + if No (N) then + return False; + + elsif Nkind_In (N, N_Handled_Sequence_Of_Statements, + N_If_Statement) + then + return True; + end if; + end loop; + end Within_HSS_Or_If; + + -- Start of processing for Set_Public_Status + + 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 or function declaration that occurs in a handled sequence + -- of statements or within an if statement is the declaration for a + -- temporary object or local subprogram generated by the expander. It + -- never needs to be made public and furthermore, making it public can + -- cause back end problems. + + elsif Nkind_In (Parent (Id), N_Object_Declaration, + N_Function_Specification) + and then Within_HSS_Or_If (Id) + 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_Referenced_Modified -- + ----------------------------- + + procedure Set_Referenced_Modified (N : Node_Id; Out_Param : Boolean) is + Pref : Node_Id; + + begin + -- Deal with indexed or selected component where prefix is modified + + if Nkind (N) = N_Indexed_Component + or else + Nkind (N) = N_Selected_Component + then + Pref := Prefix (N); + + -- If prefix is access type, then it is the designated object that is + -- being modified, which means we have no entity to set the flag on. + + if No (Etype (Pref)) or else Is_Access_Type (Etype (Pref)) then + return; + + -- Otherwise chase the prefix + + else + Set_Referenced_Modified (Pref, Out_Param); + end if; + + -- Otherwise see if we have an entity name (only other case to process) + + elsif Is_Entity_Name (N) and then Present (Entity (N)) then + Set_Referenced_As_LHS (Entity (N), not Out_Param); + Set_Referenced_As_Out_Parameter (Entity (N), Out_Param); + end if; + end Set_Referenced_Modified; + + ---------------------------- + -- 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 (" from "); + Write_Location (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 + Btyp := Base_Type (Typ); + + -- Ada 2005 (AI-230): For most cases of anonymous access types, we + -- simply use the level where the type is declared. This is true for + -- stand-alone object declarations, and for anonymous access types + -- associated with components the level is the same as that of the + -- enclosing composite type. However, special treatment is needed for + -- the cases of access parameters, return objects of an anonymous access + -- type, and, in Ada 95, access discriminants of limited types. + + if Ekind (Btyp) in Access_Kind then + if Ekind (Btyp) = E_Anonymous_Access_Type then + + -- If the type is a nonlocal anonymous access type (such as for + -- an access parameter) 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. + + if not Is_Local_Anonymous_Access (Typ) then + return Scope_Depth (Standard_Standard); + + -- If this is a return object, the accessibility level is that of + -- the result subtype of the enclosing function. The test here is + -- little complicated, because we have to account for extended + -- return statements that have been rewritten as blocks, in which + -- case we have to find and the Is_Return_Object attribute of the + -- itype's associated object. It would be nice to find a way to + -- simplify this test, but it doesn't seem worthwhile to add a new + -- flag just for purposes of this test. ??? + + elsif Ekind (Scope (Btyp)) = E_Return_Statement + or else + (Is_Itype (Btyp) + and then Nkind (Associated_Node_For_Itype (Btyp)) = + N_Object_Declaration + and then Is_Return_Object + (Defining_Identifier + (Associated_Node_For_Itype (Btyp)))) + then + declare + Scop : Entity_Id; + + begin + Scop := Scope (Scope (Btyp)); + while Present (Scop) loop + exit when Ekind (Scop) = E_Function; + Scop := Scope (Scop); + end loop; + + -- Treat the return object's type as having the level of the + -- function's result subtype (as per RM05-6.5(5.3/2)). + + return Type_Access_Level (Etype (Scop)); + end; + end if; + end if; + + Btyp := Root_Type (Btyp); + + -- The accessibility level of anonymous access 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)). + + -- AI-402: access discriminants have accessibility based on the + -- object rather than the type in Ada 2005, so the above paragraph + -- doesn't apply. + + -- ??? Needs completion with rules from AI-416 + + if Ada_Version <= Ada_95 + and then 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; + + -------------------- + -- Ultimate_Alias -- + -------------------- + -- To do: add occurrences calling this new subprogram + + function Ultimate_Alias (Prim : Entity_Id) return Entity_Id is + E : Entity_Id := Prim; + + begin + while Present (Alias (E)) loop + E := Alias (E); + end loop; + + return E; + end Ultimate_Alias; + + -------------------------- + -- 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; + + -- Isn't there some better way to express the following ??? + + 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; + + --------------- + -- Unqualify -- + --------------- + + function Unqualify (Expr : Node_Id) return Node_Id is + begin + -- Recurse to handle unlikely case of multiple levels of qualification + + if Nkind (Expr) = N_Qualified_Expression then + return Unqualify (Expression (Expr)); + + -- Normal case, not a qualified expression + + else + return Expr; + end if; + end Unqualify; + + ---------------------- + -- 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); + + -- Another special check, if the expected type is an integer type, + -- but the expression is of type System.Address, and the parent is + -- an addition or subtraction operation whose left operand is the + -- expression in question and whose right operand is of an integral + -- type, then this is an attempt at address arithmetic, so give + -- appropriate message. + + elsif Is_Integer_Type (Expec_Type) + and then Is_RTE (Found_Type, RE_Address) + and then (Nkind (Parent (Expr)) = N_Op_Add + or else + Nkind (Parent (Expr)) = N_Op_Subtract) + and then Expr = Left_Opnd (Parent (Expr)) + and then Is_Integer_Type (Etype (Right_Opnd (Parent (Expr)))) + then + Error_Msg_N + ("address arithmetic not predefined in package System", + Parent (Expr)); + Error_Msg_N + ("\possible missing with/use of System.Storage_Elements", + Parent (Expr)); + return; + + -- 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_Qual_Level := 99; + Error_Msg_NE ("\\missing `WITH &;", Expr, Scope (Found_Type)); + Error_Msg_Qual_Level := 0; + 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; |