[Bug c++/70512] [6 Regression] ICE on valid code on x86_64-linux-gnu: canonical types differ for identical types
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70512 Nathan Sidwell changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |FIXED --- Comment #7 from Nathan Sidwell --- Fixed r234768.
[Bug c++/70512] [6 Regression] ICE on valid code on x86_64-linux-gnu: canonical types differ for identical types
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70512 --- Comment #6 from Nathan Sidwell --- Author: nathan Date: Tue Apr 5 23:47:21 2016 New Revision: 234768 URL: https://gcc.gnu.org/viewcvs?rev=234768=gcc=rev Log: PR c++/70512 * class.c (fixup_may_alias): New. (fixup_attribute_variants): Call it. * g++.dg/ext/attribute-may-alias-5.C: New. Added: trunk/gcc/testsuite/g++.dg/ext/attribute-may-alias-5.C Modified: trunk/gcc/cp/ChangeLog trunk/gcc/cp/class.c trunk/gcc/testsuite/ChangeLog
[Bug c++/70512] [6 Regression] ICE on valid code on x86_64-linux-gnu: canonical types differ for identical types
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70512 --- Comment #5 from Marek Polacek --- (In reply to Nathan Sidwell from comment #3) > Are you working on that? If so, please reassign this bug. I'm not currently. But I think the approach you outlines makes sense; I just didn't get round to write any code.
[Bug c++/70512] [6 Regression] ICE on valid code on x86_64-linux-gnu: canonical types differ for identical types
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70512 --- Comment #4 from Jakub Jelinek --- I'd note that we likely need to modify them in-place, as PARM_DECLs etc. with those types already will be around. for (t = TYPE_POINTER_TO (to_type); t; t = TYPE_NEXT_PTR_TO (t)) and for (t = TYPE_REFERENCE_TO (to_type); t; t = TYPE_NEXT_REF_TO (t)) walking perhaps should do it.
[Bug c++/70512] [6 Regression] ICE on valid code on x86_64-linux-gnu: canonical types differ for identical types
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70512 Nathan Sidwell changed: What|Removed |Added Status|NEW |ASSIGNED CC||nathan at gcc dot gnu.org Assignee|unassigned at gcc dot gnu.org |nathan at gcc dot gnu.org --- Comment #3 from Nathan Sidwell --- Marek, I suspected something like what you say happening, I think we then need to go through all the 'struct S' types created during the parse and modify them? Are you working on that? If so, please reassign this bug.
[Bug c++/70512] [6 Regression] ICE on valid code on x86_64-linux-gnu: canonical types differ for identical types
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70512
Marek Polacek changed:
What|Removed |Added
CC||mpolacek at gcc dot gnu.org
--- Comment #2 from Marek Polacek ---
Jakub's testcase points to the issue here: in the original testcase, when we
parse the member declaration (operator=), we create a method with type struct
S, but because we haven't yet parsed the trailing attribute, the type doesn't
have any attributes, thus
7925 /* If the pointed-to type has the may_alias attribute set, force
7926 a TYPE_REF_CAN_ALIAS_ALL pointer to be generated. */
7927 if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (to_type)))
7928 can_alias_all = true;
in build_pointer_type_for_mode doesn't trigger. Some time after that we parse
the trailing attribute:
21318 /* Look for trailing attributes to apply to this class. */
21319 if (cp_parser_allow_gnu_extensions_p (parser))
21320 attributes = cp_parser_gnu_attributes_opt (parser);
And then we somehow arrive at finish_return_stmt -- and that will try to
convert 'this' to 'struct S', so it calls build_pointer_type again, but this
time we see the attribute and thus set TYPE_REF_CAN_ALIAS_ALL.
[Bug c++/70512] [6 Regression] ICE on valid code on x86_64-linux-gnu: canonical types differ for identical types
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70512 Richard Biener changed: What|Removed |Added Priority|P3 |P1
[Bug c++/70512] [6 Regression] ICE on valid code on x86_64-linux-gnu: canonical types differ for identical types
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70512
Jakub Jelinek changed:
What|Removed |Added
Status|UNCONFIRMED |NEW
Last reconfirmed||2016-04-04
CC||jakub at gcc dot gnu.org
Target Milestone|--- |6.0
Summary|ICE on valid code on|[6 Regression] ICE on valid
|x86_64-linux-gnu: canonical |code on x86_64-linux-gnu:
|types differ for identical |canonical types differ for
|types |identical types
Ever confirmed|0 |1
--- Comment #1 from Jakub Jelinek ---
Started with r222419.
struct __attribute__ ((__may_alias__)) S
{
S& operator= (int)
{
return *this;
}
};
works properly.
