Add a testcase for ubsan

test/ubsan.c

@@ -0,0 +1,37 @@
+/*
+ * 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;
+}