https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83131
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
Assignee|unassigned at gcc dot gnu.org |msebor at gcc dot
gnu.org
--- Comment #3 from Martin Sebor <msebor at gcc dot gnu.org> ---
Confirmed with the following test case.
extern char arr[] __attribute__ ((nonstring));
extern char str[];
int f (void)
{
return __builtin_strcmp (arr, str);
}
The expected output is:
$ gcc -O2 -S -Wall -Wextra -Wpedantic a.c
a.c: In function ‘f’:
a.c:6:10: warning: ‘__builtin_strcmp’ argument 1 declared attribute
‘nonstring’ [-Wstringop-overflow=]
return __builtin_strcmp (arr, str);
^~~~~~~~~~~~~~~~~~~~~~~~~~~
a.c:1:13: note: argument ‘arr’ declared here
extern char arr[] __attribute__ ((nonstring));
^~~
With a powerpc64le-linux GCC, there is no warning.
The strcmp call is expanded in builtins.c and never reaches expand_call in
calls.c where the checking is done. Something similar can happen for strlen on
x86_64 and there it's being handled by also checking in builtins.c (in
expand_builtin_strlen). So strcmp and other string functions will need the
same treatment.
