1 files changed, 32 insertions, 0 deletions
diff --git a/libc/fuzzing/string/strlen_fuzz.cpp b/libc/fuzzing/string/strlen_fuzz.cpp
new file mode 100644
index 0000000..dd72c19
--- /dev/null
+++ b/libc/fuzzing/string/strlen_fuzz.cpp
@@ -0,0 +1,32 @@
+//===-- strlen_fuzz.cpp ---------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// Fuzzing test for llvm-libc strlen implementation.
+///
+//===----------------------------------------------------------------------===//
+
+#include "src/string/strlen.h"
+#include <cstdint>
+#include <cstring>
+
+// always null terminate the data
+extern "C" size_t LLVMFuzzerMutate(uint8_t *data, size_t size, size_t max_size);
+extern "C" size_t LLVMFuzzerCustomMutator(uint8_t *data, size_t size,
+                                          size_t max_size, unsigned int seed) {
+  size = LLVMFuzzerMutate(data, size, max_size);
+  data[size - 1] = '\0';
+  return size;
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+  size_t ref = ::strlen(reinterpret_cast<const char *>(data));
+  size_t impl = LIBC_NAMESPACE::strlen(reinterpret_cast<const char *>(data));
+  if (ref != impl)
+    __builtin_trap();
+  return 0;
+}