------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- E X P _ P R A G --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2010, 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 Debug; use Debug;
with Einfo; use Einfo;
with Errout; use Errout;
with Exp_Ch11; use Exp_Ch11;
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 Restrict; use Restrict;
with Rident; use Rident;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
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;
function Arg3 (N : Node_Id) return Node_Id;
-- Obtain specified pragma argument expression
procedure Expand_Pragma_Abort_Defer (N : Node_Id);
procedure Expand_Pragma_Check (N : Node_Id);
procedure Expand_Pragma_Common_Object (N : Node_Id);
procedure Expand_Pragma_Import_Or_Interface (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);
procedure Expand_Pragma_Relative_Deadline (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;
----------
-- Arg3 --
----------
function Arg3 (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 : Node_Id := Next (Arg1);
begin
if No (Arg) then
return Empty;
else
Next (Arg);
if Present (Arg)
and then Nkind (Arg) = N_Pragma_Argument_Association
then
return Expression (Arg);
else
return Arg;
end if;
end if;
end;
end if;
end Arg3;
---------------------
-- Expand_N_Pragma --
---------------------
procedure Expand_N_Pragma (N : Node_Id) is
Pname : constant Name_Id := Pragma_Name (N);
begin
-- Note: we may have a pragma whose Pragma_Identifier field is not a
-- recognized pragma, and we must ignore it at this stage.
if Is_Pragma_Name (Pname) then
case Get_Pragma_Id (Pname) is
-- Pragmas requiring special expander action
when Pragma_Abort_Defer =>
Expand_Pragma_Abort_Defer (N);
when Pragma_Check =>
Expand_Pragma_Check (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_Or_Interface (N);
when Pragma_Import_Exception =>
Expand_Pragma_Import_Export_Exception (N);
when Pragma_Inspection_Point =>
Expand_Pragma_Inspection_Point (N);
when Pragma_Interface =>
Expand_Pragma_Import_Or_Interface (N);
when Pragma_Interrupt_Priority =>
Expand_Pragma_Interrupt_Priority (N);
when Pragma_Psect_Object =>
Expand_Pragma_Psect_Object (N);
when Pragma_Relative_Deadline =>
Expand_Pragma_Relative_Deadline (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_Check --
--------------------------
procedure Expand_Pragma_Check (N : Node_Id) is
Cond : constant Node_Id := Arg2 (N);
Loc : constant Source_Ptr := Sloc (Cond);
Nam : constant Name_Id := Chars (Arg1 (N));
Msg : Node_Id;
begin
-- We already know that this check is enabled, because otherwise the
-- semantic pass dealt with rewriting the assertion (see Sem_Prag)
-- Since this check is enabled, we rewrite the pragma into a
-- corresponding if statement, and then analyze the statement
-- The normal case expansion transforms:
-- pragma Check (name, 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
-- name failed at file:line if no message is given (the "name failed
-- at" is omitted for name = Assertion, since it is redundant, given
-- that the name of the exception is Assert_Failure.)
-- An alternative expansion is used when the No_Exception_Propagation
-- restriction is active and there is a local Assert_Failure handler.
-- This is not a common combination of circumstances, but it occurs in
-- the context of Aunit and the zero footprint profile. In this case we
-- generate:
-- if not condition then
-- raise Assert_Failure;
-- end if;
-- This will then be transformed into a goto, and the local handler will
-- be able to handle the assert error (which would not be the case if a
-- call is made to the Raise_Assert_Failure procedure).
-- We also generate the direct raise if the Suppress_Exception_Locations
-- is active, since we don't want to generate messages in this case.
-- Note that the reason we do not always generate a direct raise is that
-- the form in which the procedure is called allows for more efficient
-- breakpointing of assertion errors.
-- Generate the appropriate 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.
-- Case where we generate a direct raise
if ((Debug_Flag_Dot_G
or else Restriction_Active (No_Exception_Propagation))
and then Present (Find_Local_Handler (RTE (RE_Assert_Failure), N)))
or else (Opt.Exception_Locations_Suppressed and then No (Arg3 (N)))
then
Rewrite (N,
Make_If_Statement (Loc,
Condition =>
Make_Op_Not (Loc,
Right_Opnd => Cond),
Then_Statements => New_List (
Make_Raise_Statement (Loc,
Name =>
New_Reference_To (RTE (RE_Assert_Failure), Loc)))));
-- Case where we call the procedure
else
-- If we have a message given, use it
if Present (Arg3 (N)) then
Msg := Get_Pragma_Arg (Arg3 (N));
-- Here we have no string, so prepare one
else
declare
Msg_Loc : constant String := Build_Location_String (Loc);
begin
Name_Len := 0;
-- For Assert, we just use the location
if Nam = Name_Assertion then
null;
-- For predicate, we generate the string "predicate failed
-- at yyy". We prefer all lower case for predicate.
elsif Nam = Name_Predicate then
Add_Str_To_Name_Buffer ("predicate failed at ");
-- For special case of Precondition/Postcondition the string is
-- "failed xx from yy" where xx is precondition/postcondition
-- in all lower case. The reason for this different wording is
-- that the failure is not at the point of occurrence of the
-- pragma, unlike the other Check cases.
elsif Nam = Name_Precondition
or else
Nam = Name_Postcondition
then
Get_Name_String (Nam);
Insert_Str_In_Name_Buffer ("failed ", 1);
Add_Str_To_Name_Buffer (" from ");
-- For all other checks, the string is "xxx failed at yyy"
-- where xxx is the check name with current source file casing.
else
Get_Name_String (Nam);
Set_Casing (Identifier_Casing (Current_Source_File));
Add_Str_To_Name_Buffer (" failed at ");
end if;
-- In all cases, add location string
Add_Str_To_Name_Buffer (Msg_Loc);
-- Build the message
Msg := Make_String_Literal (Loc, Name_Buffer (1 .. Name_Len));
end;
end if;
-- Now rewrite as an 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 (Relocate_Node (Msg))))));
end if;
Analyze (N);
-- If new condition is always false, give a warning
if Warn_On_Assertion_Failure
and then 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 intended 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;
elsif Nam = Name_Assertion then
Error_Msg_N ("?assertion will fail at run time", N);
else
Error_Msg_N ("?check will fail at run time", N);
end if;
end if;
end Expand_Pragma_Check;
---------------------------------
-- Expand_Pragma_Common_Object --
---------------------------------
-- Use a machine attribute to replicate semantic effect in DEC Ada
-- pragma Machine_Attribute (intern_name, "common_object", extern_name);
-- For now we do nothing with the size attribute ???
-- Note: Psect_Object shares this processing
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 the pragma
Insert_After_And_Analyze (N,
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 => "common_object")),
Make_Pragma_Argument_Association (Ploc,
Expression => New_Copy_Tree (Psect)))));
end Expand_Pragma_Common_Object;
---------------------------------------
-- Expand_Pragma_Import_Or_Interface --
---------------------------------------
-- 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_Or_Interface (N : Node_Id) is
Def_Id : constant Entity_Id := Entity (Arg2 (N));
Init_Call : Node_Id;
begin
if Ekind (Def_Id) = E_Variable then
-- Find generated initialization call for object, if any
Init_Call := Find_Init_Call (Def_Id, Rep_Clause => N);
if Present (Init_Call) then
Remove (Init_Call);
end if;
-- 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_Or_Interface;
-------------------------------------------
-- 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_Temporary (Loc, 'V');
Export_Pragma : Node_Id;
Excep_Alias : Node_Id;
Excep_Object : Node_Id;
Excep_Image : String_Id;
Exdata : List_Id;
Lang_Char : 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
Lang_Char := Next (First (Exdata));
-- Change the one-character language designator to 'V'
Rewrite (Expression (Lang_Char),
Make_Character_Literal (Loc,
Chars => Name_uV,
Char_Literal_Value =>
UI_From_Int (Character'Pos ('V'))));
Analyze (Expression (Lang_Char));
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 (Loc,
Expression => Make_Identifier (Loc, Name_C)),
Make_Pragma_Argument_Association (Loc,
Expression =>
New_Reference_To (Excep_Internal, Loc)),
Make_Pragma_Argument_Association (Loc,
Expression =>
Make_String_Literal (Loc, Excep_Image)),
Make_Pragma_Argument_Association (Loc,
Expression =>
Make_String_Literal (Loc, 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)
renames Expand_Pragma_Common_Object;
-------------------------------------
-- Expand_Pragma_Relative_Deadline --
-------------------------------------
procedure Expand_Pragma_Relative_Deadline (N : Node_Id) is
P : constant Node_Id := Parent (N);
Loc : constant Source_Ptr := Sloc (N);
begin
-- Expand the pragma only in the case of the main subprogram. For tasks
-- the expansion is done in exp_ch9. Generate a call to Set_Deadline
-- at Clock plus the relative deadline specified in the pragma. Time
-- values are translated into Duration to allow for non-private
-- addition operation.
if Nkind (P) = N_Subprogram_Body then
Rewrite
(N,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Set_Deadline), Loc),
Parameter_Associations => New_List (
Unchecked_Convert_To (RTE (RO_RT_Time),
Make_Op_Add (Loc,
Left_Opnd =>
Make_Function_Call (Loc,
New_Reference_To (RTE (RO_RT_To_Duration), Loc),
New_List (Make_Function_Call (Loc,
New_Reference_To (RTE (RE_Clock), Loc)))),
Right_Opnd =>
Unchecked_Convert_To (Standard_Duration, Arg1 (N)))))));
Analyze (N);
end if;
end Expand_Pragma_Relative_Deadline;
end Exp_Prag;