Exception handling in C with setjmp and longjmp!

exception.c

#include <iso646.h>
#include <setjmp.h>
#include <stdio.h>


// Exception Macros

int _exn_handler_idx = 0;
jmp_buf _exn_handlers[1024];

#define TRY(E) { int E; _exn_handler_idx += 1;               \
    if (not (E = setjmp(_exn_handlers[_exn_handler_idx])))
#define CATCH else
#define END_TRY _exn_handler_idx -= 1; }

#define THROW(E) longjmp(_exn_handlers[_exn_handler_idx], (E))


// Exception Definitions

#define DIV_BY_ZERO_EXN 1


// Demo Code

int divide(int num, int denom) {
  if (denom == 0) {
    THROW(DIV_BY_ZERO_EXN);
  }
  return num / denom;
}

int main() {
  TRY(exception) {
    printf("%d\n", divide(1, 0));
  } CATCH {
    switch (exception) {
    case DIV_BY_ZERO_EXN:
      printf("Division by zero\n");
      return 1;
    }
  } END_TRY
  return 0;
}