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Diffstat (limited to 'gcc-4.2.1/gcc/ada/exp_prag.adb')
| -rw-r--r-- | gcc-4.2.1/gcc/ada/exp_prag.adb | 735 |
1 files changed, 735 insertions, 0 deletions
diff --git a/gcc-4.2.1/gcc/ada/exp_prag.adb b/gcc-4.2.1/gcc/ada/exp_prag.adb new file mode 100644 index 000000000..032e7a481 --- /dev/null +++ b/gcc-4.2.1/gcc/ada/exp_prag.adb @@ -0,0 +1,735 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- E X P _ P R A G -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 1992-2006, Free Software Foundation, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 2, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- +-- for more details. You should have received a copy of the GNU General -- +-- Public License distributed with GNAT; see file COPYING. If not, write -- +-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, -- +-- Boston, MA 02110-1301, USA. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- -- +------------------------------------------------------------------------------ + +with Atree; use Atree; +with Casing; use Casing; +with Einfo; use Einfo; +with Errout; use Errout; +with Exp_Ch11; use Exp_Ch11; +with Exp_Tss; use Exp_Tss; +with Exp_Util; use Exp_Util; +with Expander; use Expander; +with Namet; use Namet; +with Nlists; use Nlists; +with Nmake; use Nmake; +with Opt; use Opt; +with Rtsfind; use Rtsfind; +with Sem; use Sem; +with Sem_Eval; use Sem_Eval; +with Sem_Res; use Sem_Res; +with Sem_Util; use Sem_Util; +with Sinfo; use Sinfo; +with Sinput; use Sinput; +with Snames; use Snames; +with Stringt; use Stringt; +with Stand; use Stand; +with Targparm; use Targparm; +with Tbuild; use Tbuild; +with Uintp; use Uintp; + +package body Exp_Prag is + + ----------------------- + -- Local Subprograms -- + ----------------------- + + function Arg1 (N : Node_Id) return Node_Id; + function Arg2 (N : Node_Id) return Node_Id; + -- Obtain specified pragma argument expression + + procedure Expand_Pragma_Abort_Defer (N : Node_Id); + procedure Expand_Pragma_Assert (N : Node_Id); + procedure Expand_Pragma_Common_Object (N : Node_Id); + procedure Expand_Pragma_Import (N : Node_Id); + procedure Expand_Pragma_Import_Export_Exception (N : Node_Id); + procedure Expand_Pragma_Inspection_Point (N : Node_Id); + procedure Expand_Pragma_Interrupt_Priority (N : Node_Id); + procedure Expand_Pragma_Psect_Object (N : Node_Id); + + ---------- + -- Arg1 -- + ---------- + + function Arg1 (N : Node_Id) return Node_Id is + Arg : constant Node_Id := First (Pragma_Argument_Associations (N)); + begin + if Present (Arg) + and then Nkind (Arg) = N_Pragma_Argument_Association + then + return Expression (Arg); + else + return Arg; + end if; + end Arg1; + + ---------- + -- Arg2 -- + ---------- + + function Arg2 (N : Node_Id) return Node_Id is + Arg1 : constant Node_Id := First (Pragma_Argument_Associations (N)); + begin + if No (Arg1) then + return Empty; + else + declare + Arg : constant Node_Id := Next (Arg1); + begin + if Present (Arg) + and then Nkind (Arg) = N_Pragma_Argument_Association + then + return Expression (Arg); + else + return Arg; + end if; + end; + end if; + end Arg2; + + --------------------- + -- Expand_N_Pragma -- + --------------------- + + procedure Expand_N_Pragma (N : Node_Id) is + begin + -- Note: we may have a pragma whose chars field is not a + -- recognized pragma, and we must ignore it at this stage. + + if Is_Pragma_Name (Chars (N)) then + case Get_Pragma_Id (Chars (N)) is + + -- Pragmas requiring special expander action + + when Pragma_Abort_Defer => + Expand_Pragma_Abort_Defer (N); + + when Pragma_Assert => + Expand_Pragma_Assert (N); + + when Pragma_Common_Object => + Expand_Pragma_Common_Object (N); + + when Pragma_Export_Exception => + Expand_Pragma_Import_Export_Exception (N); + + when Pragma_Import => + Expand_Pragma_Import (N); + + when Pragma_Import_Exception => + Expand_Pragma_Import_Export_Exception (N); + + when Pragma_Inspection_Point => + Expand_Pragma_Inspection_Point (N); + + when Pragma_Interrupt_Priority => + Expand_Pragma_Interrupt_Priority (N); + + when Pragma_Psect_Object => + Expand_Pragma_Psect_Object (N); + + -- All other pragmas need no expander action + + when others => null; + end case; + end if; + + end Expand_N_Pragma; + + ------------------------------- + -- Expand_Pragma_Abort_Defer -- + ------------------------------- + + -- An Abort_Defer pragma appears as the first statement in a handled + -- statement sequence (right after the begin). It defers aborts for + -- the entire statement sequence, but not for any declarations or + -- handlers (if any) associated with this statement sequence. + + -- The transformation is to transform + + -- pragma Abort_Defer; + -- statements; + + -- into + + -- begin + -- Abort_Defer.all; + -- statements + -- exception + -- when all others => + -- Abort_Undefer.all; + -- raise; + -- at end + -- Abort_Undefer_Direct; + -- end; + + procedure Expand_Pragma_Abort_Defer (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Stm : Node_Id; + Stms : List_Id; + HSS : Node_Id; + Blk : constant Entity_Id := + New_Internal_Entity (E_Block, Current_Scope, Sloc (N), 'B'); + + begin + Stms := New_List (Build_Runtime_Call (Loc, RE_Abort_Defer)); + + loop + Stm := Remove_Next (N); + exit when No (Stm); + Append (Stm, Stms); + end loop; + + HSS := + Make_Handled_Sequence_Of_Statements (Loc, + Statements => Stms, + At_End_Proc => + New_Occurrence_Of (RTE (RE_Abort_Undefer_Direct), Loc)); + + Rewrite (N, + Make_Block_Statement (Loc, + Handled_Statement_Sequence => HSS)); + + Set_Scope (Blk, Current_Scope); + Set_Etype (Blk, Standard_Void_Type); + Set_Identifier (N, New_Occurrence_Of (Blk, Sloc (N))); + Expand_At_End_Handler (HSS, Blk); + Analyze (N); + end Expand_Pragma_Abort_Defer; + + -------------------------- + -- Expand_Pragma_Assert -- + -------------------------- + + procedure Expand_Pragma_Assert (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Cond : constant Node_Id := Arg1 (N); + Msg : String_Id; + + begin + -- We already know that assertions are enabled, because otherwise + -- the semantic pass dealt with rewriting the assertion (see Sem_Prag) + + pragma Assert (Assertions_Enabled); + + -- Since assertions are on, we rewrite the pragma with its + -- corresponding if statement, and then analyze the statement + -- The expansion transforms: + + -- pragma Assert (condition [,message]); + + -- into + + -- if not condition then + -- System.Assertions.Raise_Assert_Failure (Str); + -- end if; + + -- where Str is the message if one is present, or the default of + -- file:line if no message is given. + + -- First, we need to prepare the character literal + + if Present (Arg2 (N)) then + Msg := Strval (Expr_Value_S (Arg2 (N))); + else + Build_Location_String (Loc); + Msg := String_From_Name_Buffer; + end if; + + -- Now generate the if statement. Note that we consider this to be + -- an explicit conditional in the source, not an implicit if, so we + -- do not call Make_Implicit_If_Statement. + + Rewrite (N, + Make_If_Statement (Loc, + Condition => + Make_Op_Not (Loc, + Right_Opnd => Cond), + Then_Statements => New_List ( + Make_Procedure_Call_Statement (Loc, + Name => + New_Reference_To (RTE (RE_Raise_Assert_Failure), Loc), + Parameter_Associations => New_List ( + Make_String_Literal (Loc, Msg)))))); + + Analyze (N); + + -- If new condition is always false, give a warning + + if Nkind (N) = N_Procedure_Call_Statement + and then Is_RTE (Entity (Name (N)), RE_Raise_Assert_Failure) + then + -- If original condition was a Standard.False, we assume + -- that this is indeed intented to raise assert error + -- and no warning is required. + + if Is_Entity_Name (Original_Node (Cond)) + and then Entity (Original_Node (Cond)) = Standard_False + then + return; + else + Error_Msg_N ("?assertion will fail at run-time", N); + end if; + end if; + end Expand_Pragma_Assert; + + --------------------------------- + -- Expand_Pragma_Common_Object -- + --------------------------------- + + -- Add series of pragmas to replicate semantic effect in DEC Ada + + -- pragma Linker_Section (internal_name, external_name); + -- pragma Machine_Attribute (internal_name, "overlaid"); + -- pragma Machine_Attribute (internal_name, "global"); + -- pragma Machine_Attribute (internal_name, "initialize"); + + -- For now we do nothing with the size attribute ??? + + -- Really this expansion would be much better in the back end. The + -- front end should not need to know about target dependent, back end + -- dependent semantics ??? + + procedure Expand_Pragma_Common_Object (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + + Internal : constant Node_Id := Arg1 (N); + External : constant Node_Id := Arg2 (N); + + Psect : Node_Id; + -- Psect value upper cased as string literal + + Iloc : constant Source_Ptr := Sloc (Internal); + Eloc : constant Source_Ptr := Sloc (External); + Ploc : Source_Ptr; + + begin + -- Acquire Psect value and fold to upper case + + if Present (External) then + if Nkind (External) = N_String_Literal then + String_To_Name_Buffer (Strval (External)); + else + Get_Name_String (Chars (External)); + end if; + + Set_All_Upper_Case; + + Psect := + Make_String_Literal (Eloc, + Strval => String_From_Name_Buffer); + + else + Get_Name_String (Chars (Internal)); + Set_All_Upper_Case; + Psect := + Make_String_Literal (Iloc, + Strval => String_From_Name_Buffer); + end if; + + Ploc := Sloc (Psect); + + -- Insert pragmas + + Insert_List_After_And_Analyze (N, New_List ( + + -- The Linker_Section pragma ensures the correct section + + Make_Pragma (Loc, + Chars => Name_Linker_Section, + Pragma_Argument_Associations => New_List ( + Make_Pragma_Argument_Association (Iloc, + Expression => New_Copy_Tree (Internal)), + Make_Pragma_Argument_Association (Ploc, + Expression => New_Copy_Tree (Psect)))), + + -- Machine_Attribute "overlaid" ensures that this section + -- overlays any other sections of the same name. + + Make_Pragma (Loc, + Chars => Name_Machine_Attribute, + Pragma_Argument_Associations => New_List ( + Make_Pragma_Argument_Association (Iloc, + Expression => New_Copy_Tree (Internal)), + Make_Pragma_Argument_Association (Eloc, + Expression => + Make_String_Literal (Sloc => Ploc, + Strval => "overlaid")))), + + -- Machine_Attribute "global" ensures that section is visible + + Make_Pragma (Loc, + Chars => Name_Machine_Attribute, + Pragma_Argument_Associations => New_List ( + Make_Pragma_Argument_Association (Iloc, + Expression => New_Copy_Tree (Internal)), + Make_Pragma_Argument_Association (Eloc, + Expression => + Make_String_Literal (Sloc => Ploc, + Strval => "global")))), + + -- Machine_Attribute "initialize" ensures section is demand zeroed + + Make_Pragma (Loc, + Chars => Name_Machine_Attribute, + Pragma_Argument_Associations => New_List ( + Make_Pragma_Argument_Association (Iloc, + Expression => New_Copy_Tree (Internal)), + Make_Pragma_Argument_Association (Eloc, + Expression => + Make_String_Literal (Sloc => Ploc, + Strval => "initialize")))))); + end Expand_Pragma_Common_Object; + + -------------------------- + -- Expand_Pragma_Import -- + -------------------------- + + -- When applied to a variable, the default initialization must not be + -- done. As it is already done when the pragma is found, we just get rid + -- of the call the initialization procedure which followed the object + -- declaration. The call is inserted after the declaration, but validity + -- checks may also have been inserted and the initialization call does + -- not necessarily appear immediately after the object declaration. + + -- We can't use the freezing mechanism for this purpose, since we + -- have to elaborate the initialization expression when it is first + -- seen (i.e. this elaboration cannot be deferred to the freeze point). + + procedure Expand_Pragma_Import (N : Node_Id) is + Def_Id : constant Entity_Id := Entity (Arg2 (N)); + Typ : Entity_Id; + Init_Call : Node_Id; + + begin + if Ekind (Def_Id) = E_Variable then + Typ := Etype (Def_Id); + + -- Loop to ??? + + Init_Call := Next (Parent (Def_Id)); + while Present (Init_Call) and then Init_Call /= N loop + if Has_Non_Null_Base_Init_Proc (Typ) + and then Nkind (Init_Call) = N_Procedure_Call_Statement + and then Is_Entity_Name (Name (Init_Call)) + and then Entity (Name (Init_Call)) = Base_Init_Proc (Typ) + then + Remove (Init_Call); + exit; + else + Next (Init_Call); + end if; + end loop; + + -- Any default initialization expression should be removed + -- (e.g., null defaults for access objects, zero initialization + -- of packed bit arrays). Imported objects aren't allowed to + -- have explicit initialization, so the expression must have + -- been generated by the compiler. + + if No (Init_Call) + and then Present (Expression (Parent (Def_Id))) + then + Set_Expression (Parent (Def_Id), Empty); + end if; + end if; + end Expand_Pragma_Import; + + ------------------------------------------- + -- Expand_Pragma_Import_Export_Exception -- + ------------------------------------------- + + -- For a VMS exception fix up the language field with "VMS" + -- instead of "Ada" (gigi needs this), create a constant that will be the + -- value of the VMS condition code and stuff the Interface_Name field + -- with the unexpanded name of the exception (if not already set). + -- For a Ada exception, just stuff the Interface_Name field + -- with the unexpanded name of the exception (if not already set). + + procedure Expand_Pragma_Import_Export_Exception (N : Node_Id) is + begin + -- This pragma is only effective on OpenVMS systems, it was ignored + -- on non-VMS systems, and we need to ignore it here as well. + + if not OpenVMS_On_Target then + return; + end if; + + declare + Id : constant Entity_Id := Entity (Arg1 (N)); + Call : constant Node_Id := Register_Exception_Call (Id); + Loc : constant Source_Ptr := Sloc (N); + + begin + if Present (Call) then + declare + Excep_Internal : constant Node_Id := + Make_Defining_Identifier + (Loc, New_Internal_Name ('V')); + Export_Pragma : Node_Id; + Excep_Alias : Node_Id; + Excep_Object : Node_Id; + Excep_Image : String_Id; + Exdata : List_Id; + Lang1 : Node_Id; + Lang2 : Node_Id; + Lang3 : Node_Id; + Code : Node_Id; + + begin + if Present (Interface_Name (Id)) then + Excep_Image := Strval (Interface_Name (Id)); + else + Get_Name_String (Chars (Id)); + Set_All_Upper_Case; + Excep_Image := String_From_Name_Buffer; + end if; + + Exdata := Component_Associations (Expression (Parent (Id))); + + if Is_VMS_Exception (Id) then + Lang1 := Next (First (Exdata)); + Lang2 := Next (Lang1); + Lang3 := Next (Lang2); + + Rewrite (Expression (Lang1), + Make_Character_Literal (Loc, + Chars => Name_uV, + Char_Literal_Value => + UI_From_Int (Character'Pos ('V')))); + Analyze (Expression (Lang1)); + + Rewrite (Expression (Lang2), + Make_Character_Literal (Loc, + Chars => Name_uM, + Char_Literal_Value => + UI_From_Int (Character'Pos ('M')))); + Analyze (Expression (Lang2)); + + Rewrite (Expression (Lang3), + Make_Character_Literal (Loc, + Chars => Name_uS, + Char_Literal_Value => + UI_From_Int (Character'Pos ('S')))); + Analyze (Expression (Lang3)); + + if Exception_Code (Id) /= No_Uint then + Code := + Make_Integer_Literal (Loc, + Intval => Exception_Code (Id)); + + Excep_Object := + Make_Object_Declaration (Loc, + Defining_Identifier => Excep_Internal, + Object_Definition => + New_Reference_To (RTE (RE_Exception_Code), Loc)); + + Insert_Action (N, Excep_Object); + Analyze (Excep_Object); + + Start_String; + Store_String_Int + (UI_To_Int (Exception_Code (Id)) / 8 * 8); + + Excep_Alias := + Make_Pragma + (Loc, + Name_Linker_Alias, + New_List + (Make_Pragma_Argument_Association + (Sloc => Loc, + Expression => + New_Reference_To (Excep_Internal, Loc)), + + Make_Pragma_Argument_Association + (Sloc => Loc, + Expression => + Make_String_Literal + (Sloc => Loc, + Strval => End_String)))); + + Insert_Action (N, Excep_Alias); + Analyze (Excep_Alias); + + Export_Pragma := + Make_Pragma + (Loc, + Name_Export, + New_List + (Make_Pragma_Argument_Association + (Sloc => Loc, + Expression => Make_Identifier (Loc, Name_C)), + + Make_Pragma_Argument_Association + (Sloc => Loc, + Expression => + New_Reference_To (Excep_Internal, Loc)), + + Make_Pragma_Argument_Association + (Sloc => Loc, + Expression => + Make_String_Literal + (Sloc => Loc, + Strval => Excep_Image)), + + Make_Pragma_Argument_Association + (Sloc => Loc, + Expression => + Make_String_Literal + (Sloc => Loc, + Strval => Excep_Image)))); + + Insert_Action (N, Export_Pragma); + Analyze (Export_Pragma); + + else + Code := + Unchecked_Convert_To (RTE (RE_Exception_Code), + Make_Function_Call (Loc, + Name => + New_Reference_To (RTE (RE_Import_Value), Loc), + Parameter_Associations => New_List + (Make_String_Literal (Loc, + Strval => Excep_Image)))); + end if; + + Rewrite (Call, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To + (RTE (RE_Register_VMS_Exception), Loc), + Parameter_Associations => New_List ( + Code, + Unchecked_Convert_To (RTE (RE_Exception_Data_Ptr), + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Id, Loc), + Attribute_Name => Name_Unrestricted_Access))))); + + Analyze_And_Resolve (Code, RTE (RE_Exception_Code)); + Analyze (Call); + end if; + + if No (Interface_Name (Id)) then + Set_Interface_Name (Id, + Make_String_Literal + (Sloc => Loc, + Strval => Excep_Image)); + end if; + end; + end if; + end; + end Expand_Pragma_Import_Export_Exception; + + ------------------------------------ + -- Expand_Pragma_Inspection_Point -- + ------------------------------------ + + -- If no argument is given, then we supply a default argument list that + -- includes all objects declared at the source level in all subprograms + -- that enclose the inspection point pragma. + + procedure Expand_Pragma_Inspection_Point (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + A : List_Id; + Assoc : Node_Id; + S : Entity_Id; + E : Entity_Id; + + begin + if No (Pragma_Argument_Associations (N)) then + A := New_List; + S := Current_Scope; + + while S /= Standard_Standard loop + E := First_Entity (S); + while Present (E) loop + if Comes_From_Source (E) + and then Is_Object (E) + and then not Is_Entry_Formal (E) + and then Ekind (E) /= E_Component + and then Ekind (E) /= E_Discriminant + and then Ekind (E) /= E_Generic_In_Parameter + and then Ekind (E) /= E_Generic_In_Out_Parameter + then + Append_To (A, + Make_Pragma_Argument_Association (Loc, + Expression => New_Occurrence_Of (E, Loc))); + end if; + + Next_Entity (E); + end loop; + + S := Scope (S); + end loop; + + Set_Pragma_Argument_Associations (N, A); + end if; + + -- Expand the arguments of the pragma. Expanding an entity reference + -- is a noop, except in a protected operation, where a reference may + -- have to be transformed into a reference to the corresponding prival. + -- Are there other pragmas that may require this ??? + + Assoc := First (Pragma_Argument_Associations (N)); + + while Present (Assoc) loop + Expand (Expression (Assoc)); + Next (Assoc); + end loop; + end Expand_Pragma_Inspection_Point; + + -------------------------------------- + -- Expand_Pragma_Interrupt_Priority -- + -------------------------------------- + + -- Supply default argument if none exists (System.Interrupt_Priority'Last) + + procedure Expand_Pragma_Interrupt_Priority (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + + begin + if No (Pragma_Argument_Associations (N)) then + Set_Pragma_Argument_Associations (N, New_List ( + Make_Pragma_Argument_Association (Loc, + Expression => + Make_Attribute_Reference (Loc, + Prefix => + New_Occurrence_Of (RTE (RE_Interrupt_Priority), Loc), + Attribute_Name => Name_Last)))); + end if; + end Expand_Pragma_Interrupt_Priority; + + -------------------------------- + -- Expand_Pragma_Psect_Object -- + -------------------------------- + + -- Convert to Common_Object, and expand the resulting pragma + + procedure Expand_Pragma_Psect_Object (N : Node_Id) is + begin + Set_Chars (N, Name_Common_Object); + Expand_Pragma_Common_Object (N); + end Expand_Pragma_Psect_Object; + +end Exp_Prag; |