1 files changed, 45 insertions, 0 deletions
diff --git a/libc/fuzzing/stdlib/quick_sort_fuzz.cpp b/libc/fuzzing/stdlib/quick_sort_fuzz.cpp
new file mode 100644
index 000000000000..6371e851d2fc
--- /dev/null
+++ b/libc/fuzzing/stdlib/quick_sort_fuzz.cpp
@@ -0,0 +1,45 @@
+//===-- quick_sort_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 quick_sort implementation.
+///
+//===----------------------------------------------------------------------===//
+
+#include "src/stdlib/qsort_util.h"
+#include <stdint.h>
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+  const size_t array_size = size / sizeof(int);
+  if (array_size == 0)
+    return 0;
+
+  int *array = new int[array_size];
+  const int *data_as_int = reinterpret_cast<const int *>(data);
+  for (size_t i = 0; i < array_size; ++i)
+    array[i] = data_as_int[i];
+
+  const auto is_less = [](const void *a_ptr,
+                          const void *b_ptr) noexcept -> bool {
+    const int &a = *static_cast<const int *>(a_ptr);
+    const int &b = *static_cast<const int *>(b_ptr);
+
+    return a < b;
+  };
+
+  constexpr bool USE_QUICKSORT = true;
+  LIBC_NAMESPACE::internal::unstable_sort_impl<USE_QUICKSORT>(
+      array, array_size, sizeof(int), is_less);
+
+  for (size_t i = 0; i < array_size - 1; ++i) {
+    if (array[i] > array[i + 1])
+      __builtin_trap();
+  }
+
+  delete[] array;
+  return 0;
+}