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* [Bug c++/47132] New: decltype can't deduce some operator return types when defining an auto function's return
@ 2010-12-31 6:49 yacwroy at gmail dot com
2010-12-31 14:40 ` [Bug c++/47132] " redi at gcc dot gnu.org
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: yacwroy at gmail dot com @ 2010-12-31 6:49 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47132
Summary: decltype can't deduce some operator return types when
defining an auto function's return
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: yacwroy@gmail.com
Build: 168358 (patched, see specs)
Created attachment 22873
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22873
Erroneously fails to compile.
An error is generated when:
a) A template function whose return type is auto is being instantiated.
b) The function's return type is deduced via decltype.
c) The decltype expression is a compound operator (such as |=).
The error is: "sorry, unimplemented: mangling modop_expr". (Are "sorry,
unimplemented" errors already on todo lists?)
The operator parameters don't seem to matter - they can be literals, globals,
function parameters.
Compilation fails even if the function takes no arguments and the template
parameters are explicit.
The decltype only fails if used to define a function return type. An identical
decltype within the function body compiles OK and can be used to define
variables.
A non-template equivalent function compiles OK.
Only fails to compile if the function is actually instantiated.
As far as I can read there's no legitimate reason for this failure, although I
could've missed something.
And on the off chance that it should legitimately fail, the error message needs
updating.
Example code is attached. It is as trivial as I could get.
Example Output:
../test/gcc-bug-mangling_modop-1.cpp: In instantiation of ‘decltype (x
bit_ior_expr1) foo() [with tTYPE = int, decltype (x bit_ior_expr1) = int&]’:
../test/gcc-bug-mangling_modop-1.cpp:18:12: instantiated from here
../test/gcc-bug-mangling_modop-1.cpp:6:1: sorry, unimplemented: mangling
modop_expr
I searched the bug repository for "modop_expr" and got 0 hits.
Specs:
GCC: 4.6.0 20101230 (experimental)
- D/L via SVN on 31st Dec 2010.
- Build: 168358 (Trunk).
- Patched with Pedro Lamarao's "Delegating constructors" patch
(http://gcc.gnu.org/ml/gcc-patches/2007-04/msg00620.html).
- This shouldn't affect anything here.
System:
- Ubuntu 10.10 (x86-64).
- Intel Core2 Duo.
Hope this helps,
Simon.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/47132] decltype can't deduce some operator return types when defining an auto function's return
2010-12-31 6:49 [Bug c++/47132] New: decltype can't deduce some operator return types when defining an auto function's return yacwroy at gmail dot com
@ 2010-12-31 14:40 ` redi at gcc dot gnu.org
2011-05-27 17:46 ` [Bug c++/47132] [C++0x] " jason at gcc dot gnu.org
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: redi at gcc dot gnu.org @ 2010-12-31 14:40 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47132
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |rejects-valid
Status|UNCONFIRMED |NEW
Last reconfirmed| |2010.12.31 14:40:05
Ever Confirmed|0 |1
Build|168358 (patched, see specs) |
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2010-12-31 14:40:05 UTC ---
confirmed, not a regression
N.B. the Build field is for the value used for --build at configure time, e.g.
--build=i686-unknown-linux-gnu, not the svn revision. That would be shown if
you included the output of 'gcc -v' as requested in the bug reporting
guidelines, although in this case the unimplemented feature is not dependent on
any configure options.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/47132] [C++0x] decltype can't deduce some operator return types when defining an auto function's return
2010-12-31 6:49 [Bug c++/47132] New: decltype can't deduce some operator return types when defining an auto function's return yacwroy at gmail dot com
2010-12-31 14:40 ` [Bug c++/47132] " redi at gcc dot gnu.org
@ 2011-05-27 17:46 ` jason at gcc dot gnu.org
2011-05-27 19:36 ` jason at gcc dot gnu.org
2011-05-27 20:47 ` jason at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: jason at gcc dot gnu.org @ 2011-05-27 17:46 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47132
Jason Merrill <jason at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
CC| |jason at gcc dot gnu.org
AssignedTo|unassigned at gcc dot |jason at gcc dot gnu.org
|gnu.org |
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/47132] [C++0x] decltype can't deduce some operator return types when defining an auto function's return
2010-12-31 6:49 [Bug c++/47132] New: decltype can't deduce some operator return types when defining an auto function's return yacwroy at gmail dot com
2010-12-31 14:40 ` [Bug c++/47132] " redi at gcc dot gnu.org
2011-05-27 17:46 ` [Bug c++/47132] [C++0x] " jason at gcc dot gnu.org
@ 2011-05-27 19:36 ` jason at gcc dot gnu.org
2011-05-27 20:47 ` jason at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: jason at gcc dot gnu.org @ 2011-05-27 19:36 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47132
--- Comment #2 from Jason Merrill <jason at gcc dot gnu.org> 2011-05-27 19:32:33 UTC ---
Author: jason
Date: Fri May 27 19:32:30 2011
New Revision: 174357
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=174357
Log:
PR c++/47132
* mangle.c (write_expression): Handle MODOP_EXPR.
Added:
trunk/gcc/testsuite/g++.dg/abi/mangle47.C
Modified:
trunk/gcc/cp/ChangeLog
trunk/gcc/cp/mangle.c
trunk/gcc/testsuite/ChangeLog
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/47132] [C++0x] decltype can't deduce some operator return types when defining an auto function's return
2010-12-31 6:49 [Bug c++/47132] New: decltype can't deduce some operator return types when defining an auto function's return yacwroy at gmail dot com
` (2 preceding siblings ...)
2011-05-27 19:36 ` jason at gcc dot gnu.org
@ 2011-05-27 20:47 ` jason at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: jason at gcc dot gnu.org @ 2011-05-27 20:47 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47132
Jason Merrill <jason at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution| |FIXED
Target Milestone|--- |4.7.0
--- Comment #3 from Jason Merrill <jason at gcc dot gnu.org> 2011-05-27 20:45:24 UTC ---
Fixed for 4.7.
^ permalink raw reply [flat|nested] 5+ messages in thread
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2010-12-31 6:49 [Bug c++/47132] New: decltype can't deduce some operator return types when defining an auto function's return yacwroy at gmail dot com
2010-12-31 14:40 ` [Bug c++/47132] " redi at gcc dot gnu.org
2011-05-27 17:46 ` [Bug c++/47132] [C++0x] " jason at gcc dot gnu.org
2011-05-27 19:36 ` jason at gcc dot gnu.org
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