* [Bug c++/63657] [4.9/5 regression] -Wunused-variable: warning supressed by virtual dtor
[not found] <bug-63657-4@http.gcc.gnu.org/bugzilla/>
@ 2014-10-28 9:07 ` rguenth at gcc dot gnu.org
2014-10-30 10:38 ` jakub at gcc dot gnu.org
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10 siblings, 0 replies; 11+ messages in thread
From: rguenth at gcc dot gnu.org @ 2014-10-28 9:07 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63657
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |diagnostic
CC| |paolo.carlini at oracle dot com
Target Milestone|--- |4.9.2
Summary|[4.9 regression] |[4.9/5 regression]
|-Wunused-variable: warning |-Wunused-variable: warning
|supressed by virtual dtor |supressed by virtual dtor
^ permalink raw reply [flat|nested] 11+ messages in thread* [Bug c++/63657] [4.9/5 regression] -Wunused-variable: warning supressed by virtual dtor
[not found] <bug-63657-4@http.gcc.gnu.org/bugzilla/>
2014-10-28 9:07 ` [Bug c++/63657] [4.9/5 regression] -Wunused-variable: warning supressed by virtual dtor rguenth at gcc dot gnu.org
@ 2014-10-30 10:38 ` jakub at gcc dot gnu.org
2014-11-02 8:50 ` paolo.carlini at oracle dot com
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From: jakub at gcc dot gnu.org @ 2014-10-30 10:38 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63657
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|4.9.2 |4.9.3
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.9.2 has been released.
^ permalink raw reply [flat|nested] 11+ messages in thread* [Bug c++/63657] [4.9/5 regression] -Wunused-variable: warning supressed by virtual dtor
[not found] <bug-63657-4@http.gcc.gnu.org/bugzilla/>
2014-10-28 9:07 ` [Bug c++/63657] [4.9/5 regression] -Wunused-variable: warning supressed by virtual dtor rguenth at gcc dot gnu.org
2014-10-30 10:38 ` jakub at gcc dot gnu.org
@ 2014-11-02 8:50 ` paolo.carlini at oracle dot com
2014-11-03 12:57 ` petschy at gmail dot com
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From: paolo.carlini at oracle dot com @ 2014-11-02 8:50 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63657
Paolo Carlini <paolo.carlini at oracle dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
CC|paolo.carlini at oracle dot com |
Resolution|--- |DUPLICATE
--- Comment #3 from Paolo Carlini <paolo.carlini at oracle dot com> ---
This is exactly the same issue as c++/61935 etc, indeed, the change is
intended.
*** This bug has been marked as a duplicate of bug 38958 ***
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[not found] <bug-63657-4@http.gcc.gnu.org/bugzilla/>
` (2 preceding siblings ...)
2014-11-02 8:50 ` paolo.carlini at oracle dot com
@ 2014-11-03 12:57 ` petschy at gmail dot com
2014-11-09 11:30 ` petschy at gmail dot com
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From: petschy at gmail dot com @ 2014-11-03 12:57 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63657
--- Comment #4 from petschy at gmail dot com ---
Sorry, but this is definitely not the same issue. Bug 38958 is about returning
by value and binding to a reference. This issue is about returning a REFERENCE
and binding it to a reference. No class ctor/dtor/copy is involved, references
are just syntactic sugar on pointers: a single pointer is returned and stored
locally. This is 100% sure, since in the production code the bug appeared with
a singleton which is not constructible/destructible/copyable to the outside
world.
Please reopen the issue.
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[not found] <bug-63657-4@http.gcc.gnu.org/bugzilla/>
` (3 preceding siblings ...)
2014-11-03 12:57 ` petschy at gmail dot com
@ 2014-11-09 11:30 ` petschy at gmail dot com
2014-11-09 17:12 ` paolo.carlini at oracle dot com
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From: petschy at gmail dot com @ 2014-11-09 11:30 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63657
petschy at gmail dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |UNCONFIRMED
Resolution|DUPLICATE |---
--- Comment #5 from petschy at gmail dot com ---
To further prove my case, here is the disassembly of foo() and bar(). As
expected, they are identical, no ctors/dtors are ever called, so there can be
no side effects.
Dump of assembler code for function foo():
0x0000000000400766 <+0>: push %rbp
0x0000000000400767 <+1>: mov %rsp,%rbp
0x000000000040076a <+4>: sub $0x10,%rsp
0x000000000040076e <+8>: callq 0x400797 <getfoo()>
0x0000000000400773 <+13>: mov %rax,-0x8(%rbp)
0x0000000000400777 <+17>: leaveq
0x0000000000400778 <+18>: retq
End of assembler dump.
Dump of assembler code for function bar():
0x0000000000400779 <+0>: push %rbp
0x000000000040077a <+1>: mov %rsp,%rbp
0x000000000040077d <+4>: sub $0x10,%rsp
0x0000000000400781 <+8>: callq 0x4007a2 <getbar()>
0x0000000000400786 <+13>: mov %rax,-0x8(%rbp)
0x000000000040078a <+17>: leaveq
0x000000000040078b <+18>: retq
End of assembler dump.
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[not found] <bug-63657-4@http.gcc.gnu.org/bugzilla/>
` (4 preceding siblings ...)
2014-11-09 11:30 ` petschy at gmail dot com
@ 2014-11-09 17:12 ` paolo.carlini at oracle dot com
2014-11-22 2:23 ` jason at gcc dot gnu.org
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From: paolo.carlini at oracle dot com @ 2014-11-09 17:12 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63657
Paolo Carlini <paolo.carlini at oracle dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jason at gcc dot gnu.org,
| |paolo.carlini at oracle dot com
--- Comment #6 from Paolo Carlini <paolo.carlini at oracle dot com> ---
It occurs to me that a pretty robust (and in principle easy to implement) way
to decide whether we want to suppress the warning or not would be storing in a
flag of the VAR_DECL whether set_up_extended_ref_temp has been called on it.
However, I don't think we have any unused flag... Jason, what do you think?
^ permalink raw reply [flat|nested] 11+ messages in thread* [Bug c++/63657] [4.9/5 regression] -Wunused-variable: warning supressed by virtual dtor
[not found] <bug-63657-4@http.gcc.gnu.org/bugzilla/>
` (5 preceding siblings ...)
2014-11-09 17:12 ` paolo.carlini at oracle dot com
@ 2014-11-22 2:23 ` jason at gcc dot gnu.org
2014-11-24 13:39 ` [Bug c++/63657] [4.9 " rguenth at gcc dot gnu.org
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From: jason at gcc dot gnu.org @ 2014-11-22 2:23 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63657
--- Comment #7 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Sat Nov 22 02:21:35 2014
New Revision: 217957
URL: https://gcc.gnu.org/viewcvs?rev=217957&root=gcc&view=rev
Log:
PR c++/63657
PR c++/38958
* call.c (set_up_extended_ref_temp): Set TREE_USED on the reference
if the temporary has a non-trivial destructor.
* decl.c (poplevel): Don't look through references.
Added:
trunk/gcc/testsuite/g++.dg/warn/Wunused-var-22.C
Modified:
trunk/gcc/cp/ChangeLog
trunk/gcc/cp/call.c
trunk/gcc/cp/decl.c
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[not found] <bug-63657-4@http.gcc.gnu.org/bugzilla/>
` (6 preceding siblings ...)
2014-11-22 2:23 ` jason at gcc dot gnu.org
@ 2014-11-24 13:39 ` rguenth at gcc dot gnu.org
2014-11-24 13:44 ` paolo.carlini at oracle dot com
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From: rguenth at gcc dot gnu.org @ 2014-11-24 13:39 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63657
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to work| |5.0
Summary|[4.9/5 regression] |[4.9 regression]
|-Wunused-variable: warning |-Wunused-variable: warning
|supressed by virtual dtor |supressed by virtual dtor
--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed on trunk.
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[not found] <bug-63657-4@http.gcc.gnu.org/bugzilla/>
` (7 preceding siblings ...)
2014-11-24 13:39 ` [Bug c++/63657] [4.9 " rguenth at gcc dot gnu.org
@ 2014-11-24 13:44 ` paolo.carlini at oracle dot com
2014-11-24 16:55 ` rguenth at gcc dot gnu.org
2015-01-07 15:18 ` jason at gcc dot gnu.org
10 siblings, 0 replies; 11+ messages in thread
From: paolo.carlini at oracle dot com @ 2014-11-24 13:44 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63657
Paolo Carlini <paolo.carlini at oracle dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2014-11-24
Ever confirmed|0 |1
^ permalink raw reply [flat|nested] 11+ messages in thread* [Bug c++/63657] [4.9 regression] -Wunused-variable: warning supressed by virtual dtor
[not found] <bug-63657-4@http.gcc.gnu.org/bugzilla/>
` (8 preceding siblings ...)
2014-11-24 13:44 ` paolo.carlini at oracle dot com
@ 2014-11-24 16:55 ` rguenth at gcc dot gnu.org
2015-01-07 15:18 ` jason at gcc dot gnu.org
10 siblings, 0 replies; 11+ messages in thread
From: rguenth at gcc dot gnu.org @ 2014-11-24 16:55 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63657
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Priority|P3 |P2
Known to work| |4.8.3
Known to fail| |4.9.1
^ permalink raw reply [flat|nested] 11+ messages in thread* [Bug c++/63657] [4.9 regression] -Wunused-variable: warning supressed by virtual dtor
[not found] <bug-63657-4@http.gcc.gnu.org/bugzilla/>
` (9 preceding siblings ...)
2014-11-24 16:55 ` rguenth at gcc dot gnu.org
@ 2015-01-07 15:18 ` jason at gcc dot gnu.org
10 siblings, 0 replies; 11+ messages in thread
From: jason at gcc dot gnu.org @ 2015-01-07 15:18 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63657
--- Comment #9 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Wed Jan 7 15:18:05 2015
New Revision: 219306
URL: https://gcc.gnu.org/viewcvs?rev=219306&root=gcc&view=rev
Log:
PR c++/63657
PR c++/38958
* call.c (set_up_extended_ref_temp): Set TREE_USED on the reference
if the temporary has a non-trivial destructor.
* decl.c (poplevel): Don't look through references.
Added:
branches/gcc-4_9-branch/gcc/testsuite/g++.dg/warn/Wunused-var-22.C
Modified:
branches/gcc-4_9-branch/gcc/cp/ChangeLog
branches/gcc-4_9-branch/gcc/cp/call.c
branches/gcc-4_9-branch/gcc/cp/decl.c
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