GCC warn for non-freed heap blocks

Question

So the question is simple is there a way to tell the GCC that I want to get warned if I do not free a heap allocated block? I know that we can have non-freed blocks for some purposes/we already reached end of program or something like that.

int main(){
    int *a = malloc(sizeof(int));
    return 0;
}

If I can get a warning even for this it would be awesome.

Answer 1

This is not a possible job for GCC to do. Static analysis cannot prove that a free is forgotten, that's the job of run-time analysers like valgrind's memcheck, or eventually gcc -fsanitize=leak, which I haven't seen there yet, only with clang -fsanitize=leak.

But you won't get a compile-time warning, even when gcc or clang supports it. It will be a run-time warning.

Answer 2

The compiler cannot predict and warn for non-freed blocks. This is runtime job, not compile time. You can implement your own malloc-free-check subsystem or modify memory management library.