1 files changed, 32 insertions, 0 deletions
diff --git a/tools/fuzzing/common/FuzzingMutate.cpp b/tools/fuzzing/common/FuzzingMutate.cpp
new file mode 100644
index 0000000000..bb5e930125
--- /dev/null
+++ b/tools/fuzzing/common/FuzzingMutate.cpp
@@ -0,0 +1,32 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "FuzzingMutate.h"
+#include "FuzzingTraits.h"
+
+namespace mozilla {
+namespace fuzzing {
+
+/**
+ * Randomly mutates a byte inside |aData| by using bit manipulation.
+ */
+/* static */
+void FuzzingMutate::ChangeBit(uint8_t* aData, size_t aLength) {
+  size_t offset = RandomIntegerRange<size_t>(0, aLength);
+  aData[offset] ^= (1 << FuzzingTraits::Random(9));
+}
+
+/**
+ * Randomly replaces a byte inside |aData| with one in the range of [0, 255].
+ */
+/* static */
+void FuzzingMutate::ChangeByte(uint8_t* aData, size_t aLength) {
+  size_t offset = RandomIntegerRange<size_t>(0, aLength);
+  aData[offset] = RandomInteger<unsigned char>();
+}
+
+}  // namespace fuzzing
+}  // namespace mozilla