Minimal code:
#include <stdio.h>
#include <stdint.h>
// gcc test.c
// gcc 11.2.1 20210816 [revision 056e324ce46a7924b5cf10f61010cf9dd2ca10e9]
// bug
// test.c:41:5: Warning: «test_bug» accessing 8 bytes in a region of size 4 [-Wstringop-overflow=]
typedef struct test_struct
{
int type;
const char *file; // removing this fix warning
int line; // removing this fix warning
} test_struct;
// warning only when ext_names is second argument
test_struct test_bug(uint32_t *queue_info_count, const char *ext_names[]){
test_struct retval = (test_struct){ .type = 0,};
printf("test_bug %s\n",ext_names[*queue_info_count]);
return retval;
}
// no warning
test_struct test_no_bug(const char *ext_names[], uint32_t *queue_info_count){
test_struct retval = (test_struct){ .type = 0,};
printf("test_no_bug %s\n",ext_names[*queue_info_count]);
return retval;
}
int main(void)
{
printf("Hello, world!\n");
uint32_t queue_info_count = 0;
const char *extension_names[] = {
"test",
};
test_bug(&queue_info_count, extension_names); // warning
test_no_bug(extension_names, &queue_info_count); // no warning
return 0;
}
Compiling this code with GCC 11 always show warning on line 41 test_bug.
Clang and other versions of GCC do not show any warnings.
Is this a bug? How to make this code correctly then? Thanks.
Original code where I got this warning is very large, and test_bug function used hundreds of times from many parts of code, and there just single warning in middle of logic.
