libfuzzer library integration tests (#681)

src/integration-tests/libfuzzer-dlopen/main.c

@@ -0,0 +1,39 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+#include <assert.h>
+#include <dlfcn.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int (*fuzz_func)(const uint8_t *data, size_t size);
+
+int LLVMFuzzerInitialize(int *argc, char ***argv)
+{
+    printf("initialize\n");
+    void *handle;
+    int (*b)(void);
+    char *error;
+
+    handle = dlopen("libbad.so", RTLD_LAZY);
+    if (!handle)
+    {
+        printf("can't open %s", dlerror());
+        return 1;
+    }
+    fuzz_func = (int (*)(const uint8_t *data, size_t size))dlsym(handle, "func");
+    error = dlerror();
+    if (error != NULL)
+    {
+        printf("%s\n", error);
+        exit(EXIT_FAILURE);
+    }
+    return 0;
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
+{
+    assert(fuzz_func != NULL);
+    return fuzz_func(data, size);
+}