https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100670
Bug ID: 100670
Summary: unused attribute ignored on function definition
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: vries at gcc dot gnu.org
Target Milestone: ---
Consider the following test-case:
...
$ cat foo.c
typedef void *void_ptr;
static TYPE __attribute__((unused))
foo (void)
{
return 0;
}
...
Let's try with type int:
...
$ gcc-11 -c -Wall -O0 -g -Werror foo.c -DTYPE="int"
$
...
No warning.
Ok, now with void *:
...
$ gcc-11 -c -Wall -O0 -g -Werror foo.c -DTYPE="void *"
foo.c:4:1: error: ‘foo’ defined but not used [-Werror=unused-function]
4 | foo (void)
| ^~~
cc1: all warnings being treated as errors
...
Hmm, a warning.
Now with void_ptr:
...
$ gcc-11 -c -Wall -O0 -g -Werror foo.c -DTYPE="void_ptr"
$
...
again no warning.
My expectation was that there would be no warning for the "void *" case.
I cannot tell from the gcc attributes syntax documentation what is the correct
behaviour.
If this is not a compiler bug, then I suggest this is changed into a
documentation PR.
Note that there is at least one example that uses this style (
https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#Common-Function-Attributes
):
...
void __attribute__ ((visibility ("protected")))
f () { /* Do something. */; }
...
