https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79585
Bug ID: 79585
Summary: spurious -Wunused-variable on a pointer with attribute
unused in function template
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
While testing a patch for bug 79548 I came across the following inconsistency.
The program is expected to compile with no warnings.
$ (set -x && cat t.C && for lang in c c++; do gcc -O2 -S -Wunused -x$lang t.C;
done)
+ cat t.C
void f ()
{
int i __attribute__ ((unused)) = 0;
int __attribute__ ((unused)) j = 0;
int* p __attribute__ ((unused)) = 0;
int* __attribute__ ((unused)) q = 0;
}
#if __cplusplus
template <class T>
void g ()
{
T a __attribute__ ((unused)) = 0;
T __attribute__ ((unused)) b = 0;
T* p __attribute__ ((unused)) = 0;
T* __attribute__ ((unused)) q = 0;
}
template void g<int>();
#endif
+ for lang in c c++
+ /build/gcc-git/gcc/xgcc -B /build/gcc-git/gcc -O2 -S -Wunused -xc t.C
+ for lang in c c++
+ /build/gcc-git/gcc/xgcc -B /build/gcc-git/gcc -O2 -S -Wunused -xc++ t.C
t.C: In instantiation of ‘void g() [with T = int]’:
t.C:23:22: required from here
t.C:19:31: warning: unused variable ‘q’ [-Wunused-variable]
T* __attribute__ ((unused)) q = 0; // bogus warning
^
