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[Bug tree-optimization/83733] -Wformat-overflow false positive for %d on bounded integer when inlining
- From: "msebor at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Mon, 08 Jan 2018 21:35:32 +0000
- Subject: [Bug tree-optimization/83733] -Wformat-overflow false positive for %d on bounded integer when inlining
- Auto-submitted: auto-generated
- References: <bug-83733-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83733
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|WAITING |NEW
CC| |msebor at gcc dot gnu.org
--- Comment #3 from Martin Sebor <msebor at gcc dot gnu.org> ---
Confirmed als on on trunk (GCC 8) with the reduced test case below. As the
warning indicates, the range gets reset to that of short.
$ cat pr83733.c && gcc -O2 -S -Wall pr83733.c
struct S { char a[9], b; };
static void f (struct S *p, int i)
{
if (i < 0 || i >= 32)
return;
__builtin_sprintf (p->a, "CMPRT%02d", i);
}
void g (struct S *p, int i, short j)
{
if (i < 0 || i >= 32)
return;
if (i == 0)
i = j;
f (p, i);
}
pr83733.c: In function ‘g’:
pr83733.c:8:34: warning: ‘%02d’ directive writing between 2 and 6 bytes into a
region of size 4 [-Wformat-overflow=]
__builtin_sprintf (p->a, "CMPRT%02d", i);
^~~~
pr83733.c:8:28: note: directive argument in the range [-32768, 32767]
__builtin_sprintf (p->a, "CMPRT%02d", i);
^~~~~~~~~~~
pr83733.c:8:3: note: ‘__builtin_sprintf’ output between 8 and 12 bytes into a
destination of size 9
__builtin_sprintf (p->a, "CMPRT%02d", i);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~