ubsan.c

/*
 * Copyright (c) 2018 Martin Storsjo
 *
 * This file is part of llvm-mingw.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <stdio.h>
#include <stdint.h>

int32_t var = INT32_MAX;

int main(int argc, char *argv[]) {
    char buf[10];
    if (argc > 1) {
        fprintf(stderr, "triggering undefined behaviour\n");
        fflush(stderr);
        var++;
    } else {
        var--;
        fprintf(stderr, "%s: A test tool for undefined behaviour sanitizer. \n"
                        "Run this with a command line argument to trigger "
                        "undefined behaviour.\n", argv[0]);
    }
    return 0;
}