https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122896
Bug ID: 122896
Summary: -Wdangling-pointer false negative with unconditional
use
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: [email protected]
Target Milestone: ---
alx@devuan:~/tmp$ cat f.c
#include <errno.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
void
f(int x, long *l, int *i, short *s)
{
if (l == NULL)
l = &(long){0};
if (i == NULL)
i = &(int){0};
if (s == NULL)
s = &(short){0};
*l = 7;
if (x) *i = 42;
if (1) *s = 7;
}
alx@devuan:~/tmp$ gcc -S -Wdangling-pointer=1 f.c
alx@devuan:~/tmp$ gcc -S -Wdangling-pointer=2 f.c
f.c: In function ‘f’:
f.c:18:19: warning: dangling pointer ‘i’ to an unnamed temporary may be used
[-Wdangling-pointer=]
18 | if (x) *i = 42;
| ~~~^~~~
f.c:12:27: note: unnamed temporary defined here
12 | i = &(int){0};
| ^
f.c:20:19: warning: dangling pointer ‘s’ to an unnamed temporary may be used
[-Wdangling-pointer=]
20 | if (1) *s = 7;
| ~~~^~~
f.c:14:29: note: unnamed temporary defined here
14 | s = &(short){0};
| ^
I see the same exact diagnostics regardless of the optimization level. I can't
trigger a diagnostic about 'l'.
