Function LLVMFuzzerTestOneInput

libs/cppdap/fuzz/fuzz.cpp:104–173

// Fuzzing main function.
// See http://llvm.org/docs/LibFuzzer.html for details.
extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
  // The first byte can optionally control fuzzing mode.
  enum class ControlMode {
    // Don't wrap the input data with a stream writer. Allows testing for stream
    // writing.
    TestStreamWriter,

    // Don't append a 'done' request. This may cause the test to take longer to
    // complete (it may have to block on a timeout), but exercises the
    // unrecognised-message cases.
    DontAppendDoneRequest,

    // Number of control modes in this enum.
    Count,
  };

  // Scan first byte for control mode.
  bool useContentStreamWriter = true;
  bool appendDoneRequest = true;
  if (size > 0 && data[0] < static_cast<uint8_t>(ControlMode::Count)) {
    useContentStreamWriter =
        data[0] != static_cast<uint8_t>(ControlMode::TestStreamWriter);
    appendDoneRequest =
        data[0] != static_cast<uint8_t>(ControlMode::DontAppendDoneRequest);
    data++;
    size--;
  }

  // in contains the input data
  auto in = std::make_shared<dap::StringBuffer>();

  dap::ContentWriter writer(in);
  if (useContentStreamWriter) {
    writer.write(std::string(reinterpret_cast<const char*>(data), size));
  } else {
    in->write(data, size);
  }

  if (appendDoneRequest) {
    writer.write(R"(
  {
      "seq": 10,
      "type": "request",
      "command": "done",
  }
    )");
  }

  // Each test is done if we receive a request, or report an error.
  Event requestOrError;

#define DAP_REQUEST(REQUEST, RESPONSE)           \
  session->registerHandler([&](const REQUEST&) { \
    requestOrError.fire();                       \
    return RESPONSE{};                           \
  });

  auto session = dap::Session::create();