https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109550
Bug ID: 109550
Summary: warning: "p" may be used uninitialized
Product: gcc
Version: 12.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: [email protected]
Target Milestone: ---
% cat test.c
#include <stdlib.h>
int f (char const *p);
void a (void)
{
char const *p = alloca (1);
f (p);
}
% gcc -c -Wall test.c
test.c: In function "a":
test.c:8:3: warning: "p" may be used uninitialized [-Wmaybe-uninitialized]
8 | f (p);
| ^~~~~
test.c:3:5: note: by argument 1 of type "const char *" to "f" declared here
3 | int f (char const *p);
| ^
It also happens with "malloc" instead of "alloca", but not with a normal
function.
The warning disappears when removing "const" in both places.
Ironically, when trying to work around the warning, I noticed that wrapping
alloca in another function gets rid of the warning. However, that would
actually be wrong (dangling pointer).
