* [Ada] Fix segfault on double record extension
@ 2016-03-27 13:02 Eric Botcazou
2016-04-02 8:57 ` Eric Botcazou
0 siblings, 1 reply; 2+ messages in thread
From: Eric Botcazou @ 2016-03-27 13:02 UTC (permalink / raw)
To: gcc-patches
[-- Attachment #1: Type: text/plain, Size: 575 bytes --]
This is a regression present on the mainline and 5 branch, for a double record
extension involving a size clause on the root type and a discriminant with
variant part on the first extension...
Tested on x86_64-suse-linux, applied on the mainline and 5 branch.
2016-03-27 Eric Botcazou <ebotcazou@adacore.com>
* gcc-interface/decl.c (components_to_record): Add special case for
single field with representation clause at offset 0.
2016-03-27 Eric Botcazou <ebotcazou@adacore.com>
* gnat.dg/specs/double_record_extension3.ads: New test.
--
Eric Botcazou
[-- Attachment #2: p.diff --]
[-- Type: text/x-patch, Size: 1268 bytes --]
Index: gcc-interface/decl.c
===================================================================
--- gcc-interface/decl.c (revision 234493)
+++ gcc-interface/decl.c (working copy)
@@ -7606,6 +7606,23 @@ components_to_record (tree gnu_record_ty
if (p_gnu_rep_list && gnu_rep_list)
*p_gnu_rep_list = chainon (*p_gnu_rep_list, gnu_rep_list);
+ /* If only one field has a rep clause and it starts at 0, put back the field
+ at the head of the regular field list. This will avoid creating a useless
+ REP part below and deal with the annoying case of an extension of a record
+ with variable size and rep clause, for which the _Parent field is forced
+ at offset 0 and has variable size, which we do not support below. */
+ else if (gnu_rep_list
+ && !DECL_CHAIN (gnu_rep_list)
+ && !variants_have_rep
+ && first_free_pos
+ && integer_zerop (first_free_pos)
+ && integer_zerop (bit_position (gnu_rep_list)))
+ {
+ DECL_CHAIN (gnu_rep_list) = gnu_field_list;
+ gnu_field_list = gnu_rep_list;
+ gnu_rep_list = NULL_TREE;
+ }
+
/* Otherwise, sort the fields by bit position and put them into their own
record, before the others, if we also have fields without rep clause. */
else if (gnu_rep_list)
[-- Attachment #3: double_record_extension3.ads --]
[-- Type: text/x-adasrc, Size: 417 bytes --]
-- { dg-do compile }
package Double_Record_Extension3 is
type Rec1 is tagged record
Id : Integer;
end record;
for Rec1 use record
Id at 8 range 0 .. 31;
end record;
type Rec2 (Size : Integer) is new Rec1 with record
Data : String (1 .. Size);
end record;
type Rec3 is new Rec2 (Size => 128) with record
Valid : Boolean;
end record;
end Double_Record_Extension3;
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [Ada] Fix segfault on double record extension
2016-03-27 13:02 [Ada] Fix segfault on double record extension Eric Botcazou
@ 2016-04-02 8:57 ` Eric Botcazou
0 siblings, 0 replies; 2+ messages in thread
From: Eric Botcazou @ 2016-04-02 8:57 UTC (permalink / raw)
To: gcc-patches
[-- Attachment #1: Type: text/plain, Size: 723 bytes --]
> This is a regression present on the mainline and 5 branch, for a double
> record extension involving a size clause on the root type and a
> discriminant with variant part on the first extension...
>
> Tested on x86_64-suse-linux, applied on the mainline and 5 branch.
>
>
> 2016-03-27 Eric Botcazou <ebotcazou@adacore.com>
>
> * gcc-interface/decl.c (components_to_record): Add special case for
> single field with representation clause at offset 0.
The attached patch restricts the change to the problematic cases.
Tested on x86_64-suse-linux, applied on the mainline and 5 branch.
* gcc-interface/decl.c (components_to_record): Restrict the previous
change to fields with variable size.
--
Eric Botcazou
[-- Attachment #2: p.diff --]
[-- Type: text/x-patch, Size: 1421 bytes --]
Index: gcc-interface/decl.c
===================================================================
--- gcc-interface/decl.c (revision 234695)
+++ gcc-interface/decl.c (working copy)
@@ -7606,13 +7606,15 @@ components_to_record (tree gnu_record_ty
if (p_gnu_rep_list && gnu_rep_list)
*p_gnu_rep_list = chainon (*p_gnu_rep_list, gnu_rep_list);
- /* If only one field has a rep clause and it starts at 0, put back the field
- at the head of the regular field list. This will avoid creating a useless
- REP part below and deal with the annoying case of an extension of a record
- with variable size and rep clause, for which the _Parent field is forced
- at offset 0 and has variable size, which we do not support below. */
+ /* Deal with the annoying case of an extension of a record with variable size
+ and partial rep clause, for which the _Parent field is forced at offset 0
+ and has variable size, which we do not support below. Note that we cannot
+ do it if the field has fixed size because we rely on the presence of the
+ REP part built below to trigger the reordering of the fields in a derived
+ record type when all the fields have a fixed position. */
else if (gnu_rep_list
&& !DECL_CHAIN (gnu_rep_list)
+ && TREE_CODE (DECL_SIZE (gnu_rep_list)) != INTEGER_CST
&& !variants_have_rep
&& first_free_pos
&& integer_zerop (first_free_pos)
^ permalink raw reply [flat|nested] 2+ messages in thread
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