procyberian/gcc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

einfo.ads (Size_Depends_On_Discriminant): Adjust description.

Browse source 
* einfo.ads (Size_Depends_On_Discriminant): Adjust description.
	* layout.adb (Compute_Size_Depends_On_Discriminant): New procedure
	to compute Set_Size_Depends_On_Discriminant.
	(Layout_Type): Call it on array types in back-end layout mode.
	* sem_util.adb (Requires_Transient_Scope): Return true for array
	types only if the size depends on the value of discriminants.
	* gcc-interface/utils2.c (build_binary_op) <MODIFY_EXPR>: Use the RHS
	type if the RHS is a call to a function that returns an unconstrained
	type with default discriminant.

From-SVN: r171402
This commit is contained in:
Eric Botcazou 2011-03-24 16:08:50 +00:00 • committed by Eric Botcazou
parent cf4a36dfe1
commit e3c4580e40
9 changed files with 151 additions and 9 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

12
gcc/ada/ChangeLog
View file

@ -1,3 +1,15 @@
2011-03-24 Eric Botcazou <ebotcazou@adacore.com>
* einfo.ads (Size_Depends_On_Discriminant): Adjust description.
* layout.adb (Compute_Size_Depends_On_Discriminant): New procedure
to compute Set_Size_Depends_On_Discriminant.
(Layout_Type): Call it on array types in back-end layout mode.
* sem_util.adb (Requires_Transient_Scope): Return true for array
types only if the size depends on the value of discriminants.
* gcc-interface/utils2.c (build_binary_op) <MODIFY_EXPR>: Use the RHS
type if the RHS is a call to a function that returns an unconstrained
type with default discriminant.
2011-03-24 Eric Botcazou <ebotcazou@adacore.com>
* gcc-interface/trans.c (gnat_to_gnu): Remove obsolete case of

6
gcc/ada/einfo.ads
View file

@ -6,7 +6,7 @@
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
-- Copyright (C) 1992-2011, 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- --
@ -3573,8 +3573,8 @@ package Einfo is
-- Size_Depends_On_Discriminant (Flag177)
-- Present in all entities for types and subtypes. Indicates that the
-- size of the type depends on the value of one or more discriminants.
-- Currently, this flag is only set in front end layout mode for arrays
-- which have one or more bounds depending on a discriminant value.
-- Currently, this flag is only set for arrays which have one or more
-- bounds depending on a discriminant value.
-- Size_Known_At_Compile_Time (Flag92)
-- Present in all entities for types and subtypes. Indicates that the

11
gcc/ada/gcc-interface/utils2.c
View file

@ -186,7 +186,7 @@ known_alignment (tree exp)
static tree
find_common_type (tree t1, tree t2)
{
/* ??? As of today, various constructs lead here with types of different
/* ??? As of today, various constructs lead to here with types of different
sizes even when both constants (e.g. tagged types, packable vs regular
component types, padded vs unpadded types, ...). While some of these
would better be handled upstream (types should be made consistent before
@ -609,6 +609,15 @@ build_binary_op (enum tree_code op_code, tree result_type,
&& !integer_zerop (TYPE_SIZE (right_type)))
operation_type = left_type;
/* If we have a call to a function that returns an unconstrained type
with default discriminant on the RHS, use the RHS type (which is
padded) as we cannot compute the size of the actual assignment. */
else if (TREE_CODE (right_operand) == CALL_EXPR
&& TYPE_IS_PADDING_P (right_type)
&& CONTAINS_PLACEHOLDER_P
(TYPE_SIZE (TREE_TYPE (TYPE_FIELDS (right_type)))))
operation_type = right_type;
/* Find the best type to use for copying between aggregate types. */
else if (((TREE_CODE (left_type) == ARRAY_TYPE
&& TREE_CODE (right_type) == ARRAY_TYPE)

60
gcc/ada/layout.adb
View file

@ -6,7 +6,7 @@
-- --
-- B o d y --
-- --
-- Copyright (C) 2001-2010, Free Software Foundation, Inc. --
-- Copyright (C) 2001-2011, 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- --
@ -109,6 +109,12 @@ package body Layout is
-- are of an enumeration type (so that the subtraction cannot be
-- done directly) by applying the Pos operator to Hi/Lo first.
procedure Compute_Size_Depends_On_Discriminant (E : Entity_Id);
-- Given an array type or an array subtype E, compute whether its size
-- depends on the value of one or more discriminants and set the flag
-- Size_Depends_On_Discriminant accordingly. This need not be called
-- in front end layout mode since it does the computation on its own.
function Expr_From_SO_Ref
(Loc : Source_Ptr;
D : SO_Ref;
@ -1289,6 +1295,49 @@ package body Layout is
end if;
end Layout_Array_Type;
------------------------------------------
-- Compute_Size_Depends_On_Discriminant --
------------------------------------------
procedure Compute_Size_Depends_On_Discriminant (E : Entity_Id) is
Indx : Node_Id;
Ityp : Entity_Id;
Lo : Node_Id;
Hi : Node_Id;
Res : Boolean := False;
begin
-- Loop to process array indexes
Indx := First_Index (E);
while Present (Indx) loop
Ityp := Etype (Indx);
-- If an index of the array is a generic formal type then there is
-- no point in determining a size for the array type.
if Is_Generic_Type (Ityp) then
return;
end if;
Lo := Type_Low_Bound (Ityp);
Hi := Type_High_Bound (Ityp);
if (Nkind (Lo) = N_Identifier
and then Ekind (Entity (Lo)) = E_Discriminant)
or else (Nkind (Hi) = N_Identifier
and then Ekind (Entity (Hi)) = E_Discriminant)
then
Res := True;
end if;
Next_Index (Indx);
end loop;
if Res then
Set_Size_Depends_On_Discriminant (E);
end if;
end Compute_Size_Depends_On_Discriminant;
-------------------
-- Layout_Object --
-------------------
@ -2631,6 +2680,15 @@ package body Layout is
Set_Alignment (E, Uint_1);
end if;
end if;
-- We need to know whether the size depends on the value of one
-- or more discriminants to select the return mechanism. Skip if
-- errors are present, to prevent cascaded messages.
if Serious_Errors_Detected = 0 then
Compute_Size_Depends_On_Discriminant (E);
end if;
end if;
end if;

8
gcc/ada/sem_util.adb
View file

@ -6,7 +6,7 @@
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
-- Copyright (C) 1992-2011, 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- --
@ -10473,11 +10473,11 @@ package body Sem_Util is
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.
-- Otherwise, we only need a transient scope if the size depends on
-- the value of one or more discriminants.
else
return not Size_Known_At_Compile_Time (Typ);
return Size_Depends_On_Discriminant (Typ);
end if;
-- All other cases do not require a transient scope

5
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,8 @@
2011-03-24 Eric Botcazou <ebotcazou@adacore.com>
* gnat.dg/array16.ad[sb]: New test.
* gnat.dg/array16.ads: New helper.
2011-03-24 Eric Botcazou <ebotcazou@adacore.com>
* gnat.dg/derived_type2.adb: New test.

22
gcc/testsuite/gnat.dg/array16.adb Normal file
View file

@ -0,0 +1,22 @@
package body Array16 is
function F1 (A : access My_T1) return My_T1 is
begin
return A.all;
end;
function F2 (A : access My_T2) return My_T2 is
begin
return A.all;
end;
procedure Proc (A : access My_T1; B : access My_T2) is
L1 : My_T1 := F1(A);
L2 : My_T2 := F2(B);
begin
if L1.D = 0 and then L2(1) = 0 then
raise Program_Error;
end if;
end;
end Array16;

31
gcc/testsuite/gnat.dg/array16.ads Normal file
View file

@ -0,0 +1,31 @@
-- { dg-do compile }
-- { dg-options "-O -gnatn -fdump-tree-optimized" }
with Array16_Pkg;
package Array16 is
type T1 (D : Integer) is record
case D is
when 1 => I : Integer;
when others => null;
end case;
end record;
type Arr is array (Integer range <>) of Integer;
type My_T1 is new T1 (Array16_Pkg.N);
type My_T2 is new Arr (1 .. Integer'Min (2, Array16_Pkg.N));
function F1 (A : access My_T1) return My_T1;
pragma Inline (F1);
function F2 (A : access My_T2) return My_T2;
pragma Inline (F2);
procedure Proc (A : access My_T1; B : access My_T2);
end Array16;
-- { dg-final { scan-tree-dump-not "secondary_stack" "optimized" } }
-- { dg-final { cleanup-tree-dump "optimized" } }

5
gcc/testsuite/gnat.dg/array16_pkg.ads Normal file
View file

@ -0,0 +1,5 @@
package Array16_Pkg is
function N return Integer;
end Array16_Pkg;