https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127932
Bug ID: 127932
Summary: Wunused-but-set-parameter when using counted_by
attribute
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: b.buschinski at googlemail dot com
Target Milestone: ---
For the code:
```
struct buffer {
int * ptr __attribute__((counted_by(len)));
unsigned int len;
};
int foo(struct buffer const buf)
{
if (buf.ptr[0] != 0) {
return 2;
}
return 1;
}
```
It gives a warning:
```
<source>:6:29: warning: parameter 'buf' set but not used
[-Wunused-but-set-parameter=]
6 | int foo(struct buffer const buf)
| ~~~~~~~~~~~~~~~~~~~~^~~
```
but "buf" is actually used.
The warning disappears when "__attribute__((counted_by(len)))" is removed.
See compiler explorer: https://godbolt.org/z/csW3YnTEf
With GCC trunk and GCC-16.2
