Could -Wall add on -Wundef by default ?

[Jonny Grant <jg@xxxxxxxx>]

Would be good for -Wundef to be on by default

We see a few times code silently left out of a build unless we use -Wundef

Example below, the bug is this file didn't have a #define PROJ_DEF 1

Jonny

// gcc -Wall -Wextra -c pre.c
#include <stdio.h>
int main()
{
#if PROJ_DEF
    printf("hello\n");
#endif

    return 0;
}