Repo created

TMessagesProj/jni/third_party/pffft/pffft_fuzzer.cc

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+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <algorithm>
+#include <array>
+#include <cassert>
+#include <cstring>
+
+#include "third_party/pffft/src/pffft.h"
+
+namespace {
+
+#if defined(TRANSFORM_REAL)
+// Real FFT.
+constexpr pffft_transform_t kTransform = PFFFT_REAL;
+constexpr size_t kSizeOfOneSample = sizeof(float);
+#elif defined(TRANSFORM_COMPLEX)
+// Complex FFT.
+constexpr pffft_transform_t kTransform = PFFFT_COMPLEX;
+constexpr size_t kSizeOfOneSample = 2 * sizeof(float);  // Real plus imaginary.
+#else
+#error FFT transform type not defined.
+#endif
+
+bool IsValidSize(size_t n) {
+  if (n == 0) {
+    return false;
+  }
+  // PFFFT only supports transforms for inputs of length N of the form
+  // N = (2^a)*(3^b)*(5^c) where a >= 5, b >=0, c >= 0.
+  constexpr std::array<int, 3> kFactors = {2, 3, 5};
+  std::array<int, kFactors.size()> factorization{};
+  for (size_t i = 0; i < kFactors.size(); ++i) {
+    const int factor = kFactors[i];
+    while (n % factor == 0) {
+      n /= factor;
+      factorization[i]++;
+    }
+  }
+  return factorization[0] >= 5 && n == 1;
+}
+
+float* AllocatePffftBuffer(size_t number_of_bytes) {
+  return static_cast<float*>(pffft_aligned_malloc(number_of_bytes));
+}
+
+}  // namespace
+
+// Entry point for LibFuzzer.
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  // Set the number of FFT points to use |data| as input vector.
+  // The latter is truncated if the number of bytes is not an integer
+  // multiple of the size of one sample (which is either a real or a complex
+  // floating point number).
+  const size_t fft_size = size / kSizeOfOneSample;
+  if (!IsValidSize(fft_size)) {
+    return 0;
+  }
+
+  const size_t number_of_bytes = fft_size * kSizeOfOneSample;
+  assert(number_of_bytes <= size);
+
+  // Allocate input and output buffers.
+  float* in = AllocatePffftBuffer(number_of_bytes);
+  float* out = AllocatePffftBuffer(number_of_bytes);
+
+  // Copy input data.
+  std::memcpy(in, reinterpret_cast<const float*>(data), number_of_bytes);
+
+  // Setup FFT.
+  PFFFT_Setup* pffft_setup = pffft_new_setup(fft_size, kTransform);
+
+  // Call different PFFFT functions to maximize the coverage.
+  pffft_transform(pffft_setup, in, out, nullptr, PFFFT_FORWARD);
+  pffft_zconvolve_accumulate(pffft_setup, out, out, out, 1.f);
+  pffft_transform_ordered(pffft_setup, in, out, nullptr, PFFFT_BACKWARD);
+
+  // Release memory.
+  pffft_aligned_free(in);
+  pffft_aligned_free(out);
+  pffft_destroy_setup(pffft_setup);
+
+  return 0;
+}