https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79289
Ian Lance Taylor <ian at airs dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |aoliva at gcc dot gnu.org,
| |jakub at gcc dot gnu.org,
| |jason at gcc dot gnu.org
--- Comment #1 from Ian Lance Taylor <ian at airs dot com> ---
I think the bug is a mismatch in how the code determines the base type to use
for the DIE in this change:
2016-11-03 Jakub Jelinek <ja...@redhat.com>
Alexandre Oliva <aol...@redhat.com>
Jason Merrill <ja...@redhat.com>
PR debug/28767
PR debug/56974
* langhooks.h (struct lang_hooks_for_types): Add type_dwarf_attribute
langhook.
* langhooks.c (lhd_type_dwarf_attribute): New function.
* langhooks-def.h (lhd_type_dwarf_attribute): Declare.
(LANG_HOOKS_TYPE_DWARF_ATTRIBUTE): Define.
(LANG_HOOKS_FOR_TYPES_INITIALIZER): Add
LANG_HOOKS_TYPE_DWARF_ATTRIBUTE.
(check_qualified_type, check_aligned_type): Call it.
* dwarf2out.c (modified_type_die): Don't use type_main_variant
for FUNCTION_TYPE or METHOD_TYPE, instead walk over variants with
check_base_type and check_lang_type.
(gen_ptr_to_mbr_type_die): If lookup_type_die is already non-NULL,
return early. For pointer-to-data-member add DW_AT_use_location
attribute.
(gen_subroutine_type_die): Add DW_AT_{,rvalue_}reference attribute
if needed.
(gen_type_die_with_usage): Don't use type_main_variant
for FUNCTION_TYPE or METHOD_TYPE, instead walk over variants with
check_base_type and check_lang_type. Formatting fixes. Call
get_debug_type langhook.
The problem is that the DIE is stored with one type variant in
gen_type_die_with_usage (the last matching variant), but looked up with a
different type variant in modified_type_die (the first matching variant).
This patch seems to fix the problem, but I can't tell whether this is correct
or whether the other obvious change is correct.
Index: gcc/dwarf2out.c
===================================================================
--- gcc/dwarf2out.c (revision 244166)
+++ gcc/dwarf2out.c (working copy)
@@ -24395,8 +24395,13 @@ gen_type_die_with_usage (tree type, dw_d
but try to canonicalize. */
tree main = TYPE_MAIN_VARIANT (type);
for (tree t = main; t; t = TYPE_NEXT_VARIANT (t))
- if (check_base_type (t, main) && check_lang_type (t, type))
- type = t;
+ {
+ if (check_base_type (t, main) && check_lang_type (t, type))
+ {
+ type = t;
+ break;
+ }
+ }
}
else if (TREE_CODE (type) != VECTOR_TYPE
&& TREE_CODE (type) != ARRAY_TYPE)
