[Bug c++/84294] attributes on a function template redeclaration silently discarded
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84294 Martin Sebor changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |FIXED --- Comment #4 from Martin Sebor --- Fixed in r258121.
[Bug c++/84294] attributes on a function template redeclaration silently discarded
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84294 --- Comment #3 from Martin Sebor --- Author: msebor Date: Fri Mar 2 00:16:52 2018 New Revision: 258121 URL: https://gcc.gnu.org/viewcvs?rev=258121&root=gcc&view=rev Log: PR c++/84294 - attributes on a function template redeclaration silently discarded gcc/cp/ChangeLog: PR c++/84294 * decl.c (check_redeclaration_no_default_args): Merge attributes specified on redeclarations of the same function template. Remove dead code. gcc/testsuite/ChangeLog: PR c++/84294 * g++.dg/ext/attr-const.C: Remove xfail. * g++.dg/ext/attr-malloc-3.C: New test. * g++.dg/ext/attr-noinline-3.C: New test. * g++.dg/ext/attr-noreturn-3.C: New test. * g++.dg/ext/attr-nothrow-3.C: New test. * g++.dg/ext/attr-pure.C: Remove xfail. Added: trunk/gcc/testsuite/g++.dg/ext/attr-noinline-3.C trunk/gcc/testsuite/g++.dg/ext/attr-noreturn-3.C trunk/gcc/testsuite/g++.dg/ext/attr-nothrow-3.C Modified: trunk/gcc/cp/ChangeLog trunk/gcc/cp/decl.c trunk/gcc/testsuite/ChangeLog trunk/gcc/testsuite/g++.dg/ext/attr-const.C trunk/gcc/testsuite/g++.dg/ext/attr-malloc-3.C trunk/gcc/testsuite/g++.dg/ext/attr-pure.C
[Bug c++/84294] attributes on a function template redeclaration silently discarded
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84294 Martin Sebor changed: What|Removed |Added Keywords||patch Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |msebor at gcc dot gnu.org --- Comment #2 from Martin Sebor --- Patch: https://gcc.gnu.org/ml/gcc-patches/2018-02/msg01625.html
[Bug c++/84294] attributes on a function template redeclaration silently discarded
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84294
Martin Sebor changed:
What|Removed |Added
Keywords||missed-optimization
Status|UNCONFIRMED |NEW
Last reconfirmed||2018-02-28
Summary|missing warning for ignored |attributes on a function
|attribute on a function |template redeclaration
|template declaration|silently discarded
Ever confirmed|0 |1
Known to fail||6.4.0, 7.3.0, 8.0
--- Comment #1 from Martin Sebor ---
I'll confirm this bug because it was the indirect cause of a number of test
suite regressions recently (bug 84617). The problem is also not just one of a
missing diagnostic but rather one of G++ failing to apply attributes specified
on a function template re-declaration that were not specified on the first
declaration of the template. I.e., it's a missed optimization opportunity.
An enhanced test case:
$cat b.C && gcc -O2 -S -Wall -Wextra -fdump-tree-optimized=/dev/stdout b.C
int f ();
int __attribute__ ((const)) f ();
void ff ()
{
int i0 = f ();
int i1 = f ();
if (i0 != i1) // folded to false
__builtin_abort ();
}
template
int g ();
template
int __attribute__ ((const)) g ();
void gg ()
{
int i0 = g();
int i1 = g();
if (i0 != i1) // not folded
__builtin_abort ();
}
template
int __attribute__ ((const)) h ();
template
int h ();
void hh ()
{
int i0 = h();
int i1 = h();
if (i0 != i1) // folded to false
__builtin_abort ();
}
;; Function ff (_Z2ffv, funcdef_no=0, decl_uid=2361, cgraph_uid=0,
symbol_order=0)
ff ()
{
[local count: 1073741825]:
return;
}
;; Function gg (_Z2ggv, funcdef_no=1, decl_uid=2371, cgraph_uid=1,
symbol_order=1)
gg ()
{
int _3;
int _5;
[local count: 1073741825]:
_3 = g ();
_5 = g ();
if (_3 != _5)
goto ; [0.00%]
else
goto ; [99.96%]
[count: 0]:
__builtin_abort ();
[local count: 1073312327]:
return;
}
;; Function hh (_Z2hhv, funcdef_no=4, decl_uid=2382, cgraph_uid=2,
symbol_order=2)
hh ()
{
[local count: 1073741825]:
return;
}
