https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84555
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |diagnostic
Status|UNCONFIRMED |NEW
Last reconfirmed| |2018-02-26
CC| |msebor at gcc dot gnu.org
Summary|strncpy warnings (and |middle-end warnings are not
|friends) are not ignorable |ignorable with pragmas when
|with pragmas when inlined |inlined
Ever confirmed|0 |1
--- Comment #2 from Martin Sebor <msebor at gcc dot gnu.org> ---
I can confirm this doesn't work as you would expect. Unfortunately, the
problem isn't limited to just -Wstringop-truncation but affects many if not all
middle-end warnings. Here's another example with -Wformat-truncation.
-Wnonnull has the same problem.
$ cat b.c && gcc -O2 -S -Wall b.c
void g (char *d, unsigned n, const char *s, int i)
{
__builtin_snprintf (d, n, "%s-%i", s, i);
}
char a[8], b[8];
void h (int i)
{
#pragma GCC diagnostic ignored "-Wformat-truncation"
g (a, sizeof a, b, i);
}
b.c: In function ‘h’:
b.c:3:33: warning: ‘%i’ directive output may be truncated writing between 1 and
11 bytes into a region of size between 0 and 7 [-Wformat-truncation=]
__builtin_snprintf (d, n, "%s-%i", s, i);
^~
b.c:3:3: note: ‘__builtin_snprintf’ output between 3 and 20 bytes into a
destination of size 8
__builtin_snprintf (d, n, "%s-%i", s, i);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
