Question

What is assumed to be the preferred way to fix “comparison between signed and unsigned integer” warnings safely? In my case I have to compare some uint_32 variables with #define constants.

Really simplified:

#define MAX(A,B) ({ __typeof__(A) __a = (A); __typeof__(B) __b = (B); __a < __b ? __b : __a; })
#define c (10)
unsigned int d = 11;
if(MAX(c,d)>10){
  //...
}

But I have really a lot of such cases – what would you suggest to solve this?

Answer 1

In this case, you can just change your constant to be unsigned as well:

#define c 10U

or alternatively, use a cast so that the typeof in your macro creates an unsigned variable:

if (MAX((unsigned)c, d) > 10) {