https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71501
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to fail| |4.8.5, 4.9.4, 5.4.0, 6.4.0,
| |7.3.0, 8.2.0, 9.0
--- Comment #4 from Martin Sebor <msebor at gcc dot gnu.org> ---
GCC 8 and 9 detect the unterminated strncpy call but not yet passing the result
to printf. I'm hoping to do it in GCC 10.
$ gcc -O2 -S -Wall pr71501.c
pr71501.c: In function ‘main’:
pr71501.c:7:9: warning: unused variable ‘n’ [-Wunused-variable]
char *n = "12345";
^
pr71501.c:9:3: warning: ‘strncpy’ output truncated before terminating nul
copying 5 bytes from a string of the same length [-Wstringop-truncation]
strncpy(c, "12345", 5);
^~~~~~~~~~~~~~~~~~~~~~
GCC 9 detects some very simple cases of passing unterminated arrays to printf:
$ cat z.c && gcc -O2 -S -Wall z.c
const char a[] = { '1', '2', '3' };
void f (void)
{
__builtin_printf ("%s", a);
}
z.c: In function ‘f’:
z.c:5:22: warning: ‘%s’ directive argument is not a nul-terminated string
[-Wformat-overflow=]
5 | __builtin_printf ("%s", a);
| ^~ ~
z.c:1:12: note: referenced argument declared here
1 | const char a[] = { '1', '2', '3' };
| ^
