Try-Catch blocks for C

Small experiment that simulates try-catch blocks in C using setjmp/longjmp. Please note that it doesn't support nested try blocks and it is not thread safe. Throwing outside of try blocks has undefined behaviour unless NO_THROW is defined. Signals that are not caught will not stop the program and will lead to the execution being continued normally after the try block.

It can handle exceptions and signals. It can simulate the functionality of try, catch(exception), catch(signal), catch_all and finally. It has rudimentary support for tracing the signals and exceptions, showing where and when they happened. Throws and retries can be turned off.

The macros that control the behaviour of the try-catch blocks must be defined before including the header file.

Usage:

#include <stdio.h>
#include <tgmath.h>
#include "trycatch.h"

float ex_sqrt(float x) {
    if (x < 0)
        throw(EX_RANGE);
    return sqrt(x);
}

int main() {
    try {
        printf("%f", ex_sqrt(5)); // The function may throw.
    } catch(EX_RANGE) {
        printf("Input error. Trying again...");
        // This will try again until the function doesn't
        // throw anymore (not recommended unless you are sure
        // this can happen).
        retry();
    } catch(EX_SIGINT) {
        printf("We have been interrupted. I repeat: we have been interrupted.");
    }

    return 0;
}

A slightly more complex example can be found in test.c.