https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87719
Bug ID: 87719
Summary: missing warning on printf %s and unterminated array
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
GCC 9 issues an unterminated array warning for calls to sprintf but not for the
equivalent calls to printf (of fprintf):
$ cat t.c && gcc -O2 -S -Wall t.c
const char a[] = { 'a', 'b' };
void f (char *d)
{
__builtin_sprintf (d, "%s", a); // warning, good
}
void g (void)
{
__builtin_printf ("%s", a); // missing warning
}
t.c: In function ‘f’:
t.c:5:26: warning: ‘%s’ directive argument is not a nul-terminated string
[-Wformat-overflow=]
5 | __builtin_sprintf (d, "%s", a); // warning, good
| ^~ ~
t.c:1:12: note: referenced argument declared here
1 | const char a[] = { 'a', 'b' };
| ^
