https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114430
Bug ID: 114430
Summary: False positive for -Wformat
Product: gcc
Version: 13.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: ad...@tho-otto.de
Target Milestone: ---
Using GCC 13.2.1, with:
#include <stdio.h>
struct WWPerson
{
char Name[12];
};
struct WWPerson WWPersons[] = {
{"Bill R"},
{"Bill R"},
{"Barry G"},
};
char item[12 + 1];
void test()
{
for (size_t i = 0; i < sizeof(WWPersons) / sizeof(struct WWPerson); i++) {
sprintf(item, "%s", WWPersons[i].Name);
}
}
When compiling with -O2, i get:
bla.c: In function ‘test’:
bla.c:18:24: warning: ‘%s’ directive writing up to 35 bytes into a region of
size 13 [-Wformat-overflow=]
18 | sprintf(item, "%s", WWPersons[i].Name);
| ^~
bla.c:18:9: note: ‘sprintf’ output between 1 and 36 bytes into a destination of
size 13
18 | sprintf(item, "%s", WWPersons[i].Name);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
I get the same warning with version 10.5.0, but not with version 9.5.0
The warning disappears when i remove one element from the array.
