This is a regression present since the 4.5.x series at least. We generate
wrong code (infinite loop for the testcase) for the renaming of a volatile
packed array with an address clause.
Tested on i586-suse-linux, applied on the trunk, 4.6 and 4.5 branches.
2012-01-21 Eric Botcazou <ebotca...@adacore.com>
PR ada/46192
* gcc-interface/decl.c (gnat_to_gnu_entity) <object>: In the case of a
renaming, preserve the volatileness through the indirection, if any.
2012-01-21 Eric Botcazou <ebotca...@adacore.com>
* gnat.dg/renaming5.ad[sb]: New test.
--
Eric Botcazou
Index: gcc-interface/decl.c
===================================================================
--- gcc-interface/decl.c (revision 183348)
+++ gcc-interface/decl.c (working copy)
@@ -1051,6 +1051,14 @@ gnat_to_gnu_entity (Entity_Id gnat_entit
entity is always accessed indirectly through it. */
else
{
+ /* We need to preserve the volatileness of the renamed
+ object through the indirection. */
+ if (TREE_THIS_VOLATILE (gnu_expr)
+ && !TYPE_VOLATILE (gnu_type))
+ gnu_type
+ = build_qualified_type (gnu_type,
+ (TYPE_QUALS (gnu_type)
+ | TYPE_QUAL_VOLATILE));
gnu_type = build_reference_type (gnu_type);
inner_const_flag = TREE_READONLY (gnu_expr);
const_flag = true;
-- PR ada/46192
-- Testcase by Rolf Ebert <rolf.ebert....@gmx.de>
-- { dg-do compile }
-- { dg-options "-O2 -fdump-tree-optimized" }
with System; use System;
package body Renaming5 is
type Bits_In_Byte is array (0 .. 7) of Boolean;
pragma Pack (Bits_In_Byte);
A : Bits_In_Byte;
for A'Address use System'To_Address(16#c0#);
pragma Volatile (A);
B : Bits_In_Byte renames A;
procedure Proc is
begin
while B (0) = False loop
null;
end loop;
end;
end Renaming5;
-- { dg-final { scan-tree-dump-times "goto" 2 "optimized" } }
-- { dg-final { cleanup-tree-dump "optimized" } }
package Renaming5 is
procedure Proc;
end Renaming5;
