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[Ada] Fix bogus alignment error for derived array
- From: Eric Botcazou <ebotcazou at adacore dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Fri, 24 Apr 2009 09:04:06 +0200
- Subject: [Ada] Fix bogus alignment error for derived array
Gigi promotes the alignment of the component type too aggressively, which
results in a conflict between the final alignment of the whole array and the
value set by the front-end through the derivation.
Tested on i586-suse-linux, applied on the mainline.
2009-04-24 Eric Botcazou <ebotcazou@adacore.com>
* gcc-interface/decl.c (gnat_to_gnu_entity) <E_Array_Type>: If an
alignment is specified, do not promote that of the component type
beyond it.
<E_Array_Subtype>: Likewise.
2009-04-24 Eric Botcazou <ebotcazou@adacore.com>
* gnat.dg/specs/pr34799.ads: Rename to rep_clause1.ads.
* gnat.dg/specs/rep_clause2.ads: New test.
--
Eric Botcazou
Index: gcc-interface/decl.c
===================================================================
--- gcc-interface/decl.c (revision 146647)
+++ gcc-interface/decl.c (working copy)
@@ -1957,11 +1957,28 @@ gnat_to_gnu_entity (Entity_Id gnat_entit
if (gnu_comp_size && !Is_Bit_Packed_Array (gnat_entity))
{
- tree orig_tem;
+ tree orig_tem = tem;
+ unsigned int max_align;
+
+ /* If an alignment is specified, use it as a cap on the component
+ type so that it can be honored for the whole type. But ignore
+ it for the original type of packed array types. */
+ if (No (Packed_Array_Type (gnat_entity))
+ && Known_Alignment (gnat_entity))
+ max_align = validate_alignment (Alignment (gnat_entity),
+ gnat_entity, 0);
+ else
+ max_align = 0;
+
tem = make_type_from_size (tem, gnu_comp_size, false);
- orig_tem = tem;
+ if (max_align > 0 && TYPE_ALIGN (tem) > max_align)
+ tem = orig_tem;
+ else
+ orig_tem = tem;
+
tem = maybe_pad_type (tem, gnu_comp_size, 0, gnat_entity,
"C_PAD", false, definition, true);
+
/* If a padding record was made, declare it now since it will
never be declared otherwise. This is necessary to ensure
that its subtrees are properly marked. */
@@ -2343,13 +2360,31 @@ gnat_to_gnu_entity (Entity_Id gnat_entit
if (gnu_comp_size && !Is_Bit_Packed_Array (gnat_entity))
{
- tree orig_gnu_type;
+ tree orig_gnu_type = gnu_type;
+ unsigned int max_align;
+
+ /* If an alignment is specified, use it as a cap on the
+ component type so that it can be honored for the whole
+ type. But ignore it for the original type of packed
+ array types. */
+ if (No (Packed_Array_Type (gnat_entity))
+ && Known_Alignment (gnat_entity))
+ max_align = validate_alignment (Alignment (gnat_entity),
+ gnat_entity, 0);
+ else
+ max_align = 0;
+
gnu_type
= make_type_from_size (gnu_type, gnu_comp_size, false);
- orig_gnu_type = gnu_type;
+ if (max_align > 0 && TYPE_ALIGN (gnu_type) > max_align)
+ gnu_type = orig_gnu_type;
+ else
+ orig_gnu_type = gnu_type;
+
gnu_type = maybe_pad_type (gnu_type, gnu_comp_size, 0,
gnat_entity, "C_PAD", false,
definition, true);
+
/* If a padding record was made, declare it now since it
will never be declared otherwise. This is necessary
to ensure that its subtrees are properly marked. */
-- { dg-do compile }
-- { dg-options "-gnatws" }
package Rep_Clause2 is
type S is new String;
for S'Component_Size use 256;
type T is new S(1..8);
end Rep_Clause2;