[libc-commits] [libc] [libc] fuzz test for heap_sort (PR #100826)

[via libc-commits]

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@@ -0,0 +1,53 @@
+//===-- heap_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 heap_sort implementation.
+///
+//===----------------------------------------------------------------------===//
+
+#include "src/stdlib/heap_sort.h"
+#include <stdint.h>
+
+static int int_compare(const void *l, const void *r) {
+  int li = *reinterpret_cast<const int *>(l);
+  int ri = *reinterpret_cast<const int *>(r);
+  if (li == ri)
+    return 0;
+  else if (li > ri)
+    return 1;
+  else
+    return -1;
+}
+
+namespace LIBC_NAMESPACE_DECL {
+
+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];
+
+  auto arr = internal::Array(reinterpret_cast<uint8_t *>(array), array_size, sizeof(int), int_compare);
+
+  internal::heap_sort(arr);
+
+  for (size_t i = 0; i < array_size - 1; ++i) {
+    if (arr.get(i) > arr.get(i + 1))
+      __builtin_trap();
+  }
----------------
overmighty wrote:

Nit: I think braces should be omitted here.

> ```cpp
> // This should also omit braces.  The `for` loop contains only a single
> // statement, so it shouldn't have braces.  The `if` also only contains a
> // single simple statement (the `for` loop), so it also should omit braces.
> if (isa<FunctionDecl>(D))
>   for (auto *A : D.attrs())
>     handleAttr(A);
> ```

https://llvm.org/docs/CodingStandards.html#don-t-use-braces-on-simple-single-statement-bodies-of-if-else-loop-statements

https://github.com/llvm/llvm-project/pull/100826