control reaches end of non-void function with custom exit function

Question

While trying to rid my code of GCC warnings I have discovered a strange bug/behaviour. My program uses a custom exit function which performs some clean-up and finally calls exit().

However my use of this exit function is causing GCC to produce spurious warnings of:

control reaches end of non-void function with custom exit function

An example of a program causing this bug is:

File1.c:

extern void CleanExit(int ExitCode);

int MyFunc(int ErrorCode)
{
    if(-1 == ErrorCode)
        return -1;
    if(1 == ErrorCode)
        return 1;
    if(2 == ErrorCode)
        return 0;
    if(3 == ErrorCode)
        CleanExit(0);
    CleanExit(-1);
}

File2.c:

void CleanExit(int ExitCode)
{
    /* Do Some Cleanup */
    exit(ExitCode);
}

Is there some way to be rid of these warnings without adding useless cruft to every function which uses this structure?

I would prefer to do so with standard C but am willing to use some kind of GCC pragma if needed.

Answer 1

You tagged your question with GCC. So instead of changing function from void to int and adding return everywhere, you can try and GCC specify attribute. Add __attribute__((noreturn)) above CleanExit() declaration. This will alert the compiler that CleanExit() will never return directly to the caller.