[Tinycc-devel] Patch: Treat func pointers with different return types as not compatible

[Arthur Williams]

I noticed a problem with tcc and _Generic that caused function pointers with different return types to be treated as compatible which would prevent the following code from compiling with the error  "error: type match twice".
I'm aware that the person who originally added _Generic support was aware of this short coming and didn't fix it because that caused memmove and other internal functions from compiling. I updated the return types/declarations of such functions so that all current tests pass.

Minimal code snippet that didn't compile with tcc and will now compile:
#include <stdio.h>
#define G(P) _Generic(P, void(*)(int a):3, int(*)():0, void(*)(void):1, int :2)
void bar(void) {}
int foo() {return 0;}
int foo2(int a) {return 0;}
void foo3(int a) {}
int main() {
    printf("%d\n", G(1));
    printf("%d\n", G(bar));
    printf("%d\n", G(foo));
    printf("%d\n", G(foo2));
    printf("%d\n", G(foo3));
}