https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94444
--- Comment #4 from felix-gcc at fefe dot de ---
Sure, here's a test case:
#include <stddef.h>
__attribute__((access(read_only,2,3), access(write_only,1,3)))
extern void* memcpy(void* dest, const void* src, size_t len);
int main() {
char buf[10];
memcpy(buf,"fnordfnord",11); // should reject or at least warn
}
$ gcc -c t.c
t.c: In function ‘main’:
t.c:8:3: warning: ‘memcpy’ writing 11 bytes into a region of size 10 overflows
the destination [-Wstringop-overflow=]
8 | memcpy(buf,"fnordfnord",11); // should reject or at least warn
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
t.c:4:14: note: in a call to function ‘memcpy’ declared with attribute
‘write_only (1, 3)’
4 | extern void* memcpy(void* dest, const void* src, size_t len);
| ^~~~~~
$ gcc -c t.c -Os
$ gcc -v
[...]
gcc version 10.0.1 20200401 (experimental) (GCC)
