[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253
--- Comment #25 from Matthijs van Duin ---
I wasn't referring to the warnings though but incorrect code generation. Since
is exhibited by pretty trivial test cases (testsuite/g++.dg/cpp0x/initlist86.C
confirms that { i++, i++ } works but the analogous test for { ++i, ++i } fails)
yet was first reported long after this bug was marked "FIXED" I kind of assumed
it was a regression, but apparently it was just never really fixed to begin
with.
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 --- Comment #24 from Jonathan Wakely --- There's no regression (see bug 70792 comment 5). G++ still warns for the testcasese here, even though it produces the right code now.
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 Matthijs van Duin changed: What|Removed |Added CC||matthijsvanduin at gmail dot com --- Comment #23 from Matthijs van Duin --- There appears to be a regression of this bug. See bug 70792.
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 Cameron dacamara.cameron at gmail dot com changed: What|Removed |Added CC||dacamara.cameron at gmail dot com --- Comment #22 from Cameron dacamara.cameron at gmail dot com --- *** Bug 62036 has been marked as a duplicate of this bug. ***
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 Jason Merrill jason at gcc dot gnu.org changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |FIXED Target Milestone|4.10.0 |4.9.1 --- Comment #21 from Jason Merrill jason at gcc dot gnu.org --- Fixed in 4.9.1.
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 --- Comment #20 from christophe.lyon at st dot com --- The problem was fixed by Jakub's commit 212289. Thanks.
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 --- Comment #19 from Jason Merrill jason at gcc dot gnu.org --- That's odd. Can you investigate further?
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 christophe.lyon at st dot com changed: What|Removed |Added CC||christophe.lyon at st dot com --- Comment #18 from christophe.lyon at st dot com --- On 4.9 branch, I've noticed that commit 212150 adds new FAILs on some configurations. g++.dg/cpp0x/initlist86.C fails at execution in the following cases (tested with qemu): target mode cpu arm-none-eabi arm cortex-a9 arm-none-linux-gnueabi arm cortex-a9 arm-none-linux-gnueabi thumb cortex-a9 arm-none-linux-gnueabihf arm cortex-a9 arm-none-linux-gnueabihf thumb cortex-a9 arm-none-linux-gnueabihf arm cortex-a9 armeb-none-linux-gnueabihf arm cortex-a9 armeb-none-linux-gnueabihf thumb cortex-a9 aarch64-none-linux the same test passes when: target mode cpu arm-none-eabi thumb cortex-a9 aarch64-none-elf aarch64_be-none-elf
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 --- Comment #17 from Jason Merrill jason at gcc dot gnu.org --- Author: jason Date: Mon Jun 30 14:25:21 2014 New Revision: 212150 URL: https://gcc.gnu.org/viewcvs?rev=212150root=gccview=rev Log: DR 1030 PR c++/51253 PR c++/61382 * cp-tree.h (CALL_EXPR_LIST_INIT_P): New. * call.c (struct z_candidate): Add flags field. (add_candidate): Add flags parm. (add_function_candidate, add_conv_candidate, build_builtin_candidate) (add_template_candidate_real): Pass it. (build_over_call): Set CALL_EXPR_LIST_INIT_P. * tree.c (build_aggr_init_expr): Copy it. * semantics.c (simplify_aggr_init_expr): Copy it. * cp-gimplify.c (cp_gimplify_expr): Handle it. Added: branches/gcc-4_9-branch/gcc/testsuite/g++.dg/cpp0x/initlist86.C Modified: branches/gcc-4_9-branch/gcc/ChangeLog branches/gcc-4_9-branch/gcc/cp/ChangeLog branches/gcc-4_9-branch/gcc/cp/call.c branches/gcc-4_9-branch/gcc/cp/cp-gimplify.c branches/gcc-4_9-branch/gcc/cp/cp-tree.h branches/gcc-4_9-branch/gcc/cp/semantics.c branches/gcc-4_9-branch/gcc/cp/tree.c branches/gcc-4_9-branch/gcc/gimplify.c branches/gcc-4_9-branch/gcc/gimplify.h
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 --- Comment #15 from Akim Demaille akim.demaille at gmail dot com --- (In reply to Jonathan Wakely from comment #13) (In reply to Akim Demaille from comment #10) auto t = std::make_tuple(incr(), incr()); That's not an initializer-list, it's a function call, so the order of evaluation is not specified and that example is not relevant AFAICT. Yes, you are right, I had also realized that afterwards. It would be nice though if the standard could ensure that perfect forwarding could preserve the guarantee on left-to-right upward: convenience functions, that wrap constructors for instance, could still be used safely.
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 --- Comment #16 from Jason Merrill jason at gcc dot gnu.org --- Author: jason Date: Wed Jun 4 15:51:01 2014 New Revision: 211235 URL: http://gcc.gnu.org/viewcvs?rev=211235root=gccview=rev Log: PR c++/51253 PR c++/61382 gcc/ * gimplify.c (gimplify_arg): Non-static. * gimplify.h: Declare it. gcc/cp/ * cp-gimplify.c (cp_gimplify_expr): Handle CALL_EXPR_LIST_INIT_P here. * semantics.c (simplify_aggr_init_expr): Not here, just copy it. Added: trunk/gcc/testsuite/g++.dg/cpp0x/initlist86.C Modified: trunk/gcc/ChangeLog trunk/gcc/cp/ChangeLog trunk/gcc/cp/cp-gimplify.c trunk/gcc/cp/semantics.c trunk/gcc/gimplify.c trunk/gcc/gimplify.h
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 --- Comment #13 from Jonathan Wakely redi at gcc dot gnu.org --- (In reply to Akim Demaille from comment #10) auto t = std::make_tuple(incr(), incr()); That's not an initializer-list, it's a function call, so the order of evaluation is not specified and that example is not relevant AFAICT.
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 --- Comment #14 from Jonathan Wakely redi at gcc dot gnu.org --- Trunk still gives -Wsequence-point warnings, and PR 61382 has an example that still fails
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 Jason Merrill jason at gcc dot gnu.org changed: What|Removed |Added Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |jason at gcc dot gnu.org Target Milestone|--- |4.10.0 --- Comment #12 from Jason Merrill jason at gcc dot gnu.org --- Fixed on trunk so far.
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 --- Comment #11 from Jason Merrill jason at gcc dot gnu.org --- Author: jason Date: Fri Apr 11 17:08:47 2014 New Revision: 209309 URL: http://gcc.gnu.org/viewcvs?rev=209309root=gccview=rev Log: DR 1030 PR c++/51253 * cp-tree.h (CALL_EXPR_LIST_INIT_P): New. * call.c (struct z_candidate): Add flags field. (add_candidate): Add flags parm. (add_function_candidate, add_conv_candidate, build_builtin_candidate) (add_template_candidate_real): Pass it. (build_over_call): Set CALL_EXPR_LIST_INIT_P. * tree.c (build_aggr_init_expr): Copy it. * semantics.c (simplify_aggr_init_expr): Preevaluate args if it's set. Modified: trunk/gcc/cp/ChangeLog trunk/gcc/cp/call.c trunk/gcc/cp/cp-tree.h trunk/gcc/cp/semantics.c trunk/gcc/cp/tree.c
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253
--- Comment #10 from Akim Demaille akim.demaille at gmail dot com ---
Well, I have finally found a simple workaround for some of the cases: GCC seems
to be right in the order of evaluation when initializing an array so:
templateint... IS
int f1()
{
int i = 0;
swallow{ i = 10 * i + IS... };
return i;
}
fails, but
templateint... IS
int f2()
{
using swallow = int[];
int i = 0;
(void) swallow{ i = 10 * i + IS... };
return i;
}
succeeds. However, GCC's own libstdc++ is exposed to this bug, for instance
make_tuple.
$ cat foo.cc
#include iostream
#include tuple
struct swallow
{
templatetypename... Types
swallow(Types ...){}
};
int incr()
{
static int res = 2;
return res++;
}
templateint... IS
int f1()
{
int i = 0;
swallow{ i = 10 * i + IS... };
return i;
}
templateint... IS
int f2()
{
using swallow = int[];
int i = 0;
(void) swallow{ i = 10 * i + IS... };
return i;
}
int main()
{
// `i = i * 2 + 2' should be sequenced before `i = i * 3 + 3'
std::cerr f12, 3() '\t';
std::cerr f22, 3() '\t';
auto t = std::make_tuple(incr(), incr());
std::cerr std::get0(t) std::get1(t) '\n';
}
$ ./a.32
232323
$ ./a.33
232323
$ ./a.34
232323
$ ./a.35
232323
$ ./a.48
322332
$ ./a.49
322332
where 32...35 is clang++, and 48,49 is gcc.
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 Paolo Carlini paolo.carlini at oracle dot com changed: What|Removed |Added CC||jason at gcc dot gnu.org --- Comment #8 from Paolo Carlini paolo.carlini at oracle dot com --- Let's add Jason in CC.
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 Manuel López-Ibáñez manu at gcc dot gnu.org changed: What|Removed |Added CC||manu at gcc dot gnu.org --- Comment #9 from Manuel López-Ibáñez manu at gcc dot gnu.org --- (In reply to Akim Demaille from comment #6) FWIW, because of this issue, I no longer use g++ for my project, which saddens me. If there were a means to put money on some bugs, I'd be happy to drop say $50. I do not pretend that should suffice, but maybe other people would be happy to put money on their bugs, and maybe in end some bugs might be worth shooting at. Sort of crowd-funding. Of course it would require some infrastructure to support this, but maybe this would be worth considering? It would be nice if such infrastructure existed. Perhaps it would motivate more people to contribute to GCC (current contributors have their hands pretty full already). I know of: https://www.bountysource.com/trackers/384568-gcc but I have never used it, so I don't know how it works.
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 --- Comment #7 from Akim Demaille akim.demaille at gmail dot com --- Hi all, I'd really love to have some feedback on this issue. It looks like nobody is having a look at this. Thanks for all the good work, and sorry for insisting.
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 --- Comment #6 from Akim Demaille akim.demaille at gmail dot com --- FWIW, because of this issue, I no longer use g++ for my project, which saddens me. If there were a means to put money on some bugs, I'd be happy to drop say $50. I do not pretend that should suffice, but maybe other people would be happy to put money on their bugs, and maybe in end some bugs might be worth shooting at. Sort of crowd-funding. Of course it would require some infrastructure to support this, but maybe this would be worth considering? Best regards.
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 --- Comment #5 from Akim Demaille akim.demaille at gmail dot com --- Happy two-year birthday, bug! Sorry I'm (slightly more that) off-by-one.
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 Stephan Tolksdorf st at quanttec dot com changed: What|Removed |Added CC||st at quanttec dot com --- Comment #4 from Stephan Tolksdorf st at quanttec dot com --- I just stumbled over this bug with the current trunk version of GCC. It's a pretty ugly bug.
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 Broes De Cat broes.decat at gmail dot com changed: What|Removed |Added CC||broes.decat at gmail dot com --- Comment #3 from Broes De Cat broes.decat at gmail dot com --- Confirmed, hit the bug with 4.7.3 in c++11 mode.
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 Akim Demaille akim.demaille at gmail dot com changed: What|Removed |Added CC||akim.demaille at gmail dot com --- Comment #2 from Akim Demaille akim.demaille at gmail dot com --- Ping. Still there with released 4.8.1 on GNU/Linux. Using initializer lists this way is a very handy way to handle variadic templates. Cheers, and thanks for all the good work!
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 Paolo Carlini paolo.carlini at oracle dot com changed: What|Removed |Added Priority|P3 |P2
[Bug c++/51253] [C++11][DR 1030] Evaluation order (sequenced-before relation) among initializer-clauses in braced-init-list
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51253 Paolo Carlini paolo.carlini at oracle dot com changed: What|Removed |Added Status|UNCONFIRMED |NEW Last reconfirmed||2012-10-10 Ever Confirmed|0 |1 --- Comment #1 from Paolo Carlini paolo.carlini at oracle dot com 2012-10-10 09:24:08 UTC --- Confirming.
