[libFuzzer] add hooks for strstr, strcasestr, strcasecmp, strncasecmp

llvm-svn: 275648
diff --git a/llvm/lib/Fuzzer/test/StrstrTest.cpp b/llvm/lib/Fuzzer/test/StrstrTest.cpp
new file mode 100644
index 0000000..90d539b6
--- /dev/null
+++ b/llvm/lib/Fuzzer/test/StrstrTest.cpp
@@ -0,0 +1,18 @@
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+
+// Test strstr and strcasestr hooks.
+#include <string>
+#include <string.h>
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+  std::string s(reinterpret_cast<const char*>(Data), Size);
+  if (strstr(s.c_str(), "FUZZ") && strcasestr(s.c_str(), "aBcD")) {
+    fprintf(stderr, "BINGO\n");
+    exit(1);
+  }
+  return 0;
+}