https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88211
Bug ID: 88211
Summary: missing warning on printf %ls and unterminated wide
member array
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
GCC correctly diagnoses the past-the-end read from the narrow character array
in f() but fails to diagnose the equivalent past-the-end read from the wide
character array in g().
$ cat t.c && gcc -O2 -S -Wall t.c
const char a[] = { 'a' };
int f (void)
{
return __builtin_snprintf (0, 0, "%s", a); // warning (good)
}
const __WCHAR_TYPE__ wa[] = { L'A' };
int g (void)
{
return __builtin_snprintf (0, 0, "%ls", wa); // missing warning
}
t.c: In function ‘f’:
t.c:4:37: warning: ‘%s’ directive argument is not a nul-terminated string
[-Wformat-truncation=]
4 | return __builtin_snprintf (0, 0, "%s", a); // warning (good)
| ^~ ~
t.c:1:12: note: referenced argument declared here
1 | const char a[] = { 'a' };
| ^
