https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87756
Bug ID: 87756
Summary: missing unterminated argument warning using address of
a constant character
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 successfully diagnoses the unterminated array argument when it's an
actual array but fails to do the same when the argument is the address of a
single character.
$ cat t.c && gcc -O2 -S -Wall t.c
const char c = 'a';
const char a[] = { 'a' };
char *d, *e;
void f (void)
{
__builtin_sprintf (d, "%s", a); // warning (good)
__builtin_sprintf (e, "%s", &c); // missing warning
}
void g (void)
{
__builtin_strcpy (d, a); // warning (good)
__builtin_strcpy (e, &c); // missing warning
}
t.c: In function ‘g’:
t.c:14:3: warning: ‘strcpy’ argument missing terminating nul
[-Wstringop-overflow=]
14 | __builtin_strcpy (d, a); // warning (good)
| ^~~~~~~~~~~~~~~~~~~~~~~
t.c:2:12: note: referenced argument declared here
2 | const char a[] = { 'a' };
| ^
t.c: In function ‘f’:
t.c:8:26: warning: ‘%s’ directive argument is not a nul-terminated string
[-Wformat-overflow=]
8 | __builtin_sprintf (d, "%s", a); // warning (good)
| ^~ ~
t.c:2:12: note: referenced argument declared here
2 | const char a[] = { 'a' };
| ^
