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[Ada] Fix segfault on double record extension
- From: Eric Botcazou <ebotcazou at adacore dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Sun, 27 Mar 2016 12:01:12 +0200
- Subject: [Ada] Fix segfault on double record extension
- Authentication-results: sourceware.org; auth=none
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
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)
-- { 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;