fuzztest/internal/logging.h

// Copyright 2022 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef FUZZTEST_FUZZTEST_INTERNAL_LOGGING_H_
#define FUZZTEST_FUZZTEST_INTERNAL_LOGGING_H_

#include <cstdio>
#include <string>

#include "absl/strings/str_cat.h"

// TODO(b/422182911): Remove this library.
namespace fuzztest::internal {

// Returns a dup-ed file descriptor pointing to the original stderr if possible.
// Otherwise returns -1 (in which case the original stderr may be used, while it
// can be silenced - see below).
//
// This function is signal-safe.
int GetStderrFdDup();

// Returns the current FILE pointing to the original stderr.
FILE* GetStderr();

// Silences all output sent to stdout and stderr, except the fuzzer's own log.
// Fuzzer should log to GetStderrFdDup()/GetStderr().
void SilenceTargetStdoutAndStderr();

// Revive the silenced stdout and stderr of target.
// Also redirect GetStderr() to stderr.
void RestoreTargetStdoutAndStderr();

// Check if FUZZTEST_SILENCE_TARGET env set.
bool IsSilenceTargetEnabled();

// This Abort function will inject `message` into the signal handler's output
// along with the file, line and test name of the currently running test.
// Meant for failures related to test setup and not the code under test itself.
[[noreturn]] void AbortInTest(const std::string& message);
extern const std::string* volatile test_abort_message;

}  // namespace fuzztest::internal

#endif  // FUZZTEST_FUZZTEST_INTERNAL_LOGGING_H_