check.cc

// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/check.h"

#include "base/check_op.h"
#include "base/debug/alias.h"
#include "base/debug/debugging_buildflags.h"
#include "base/debug/dump_without_crashing.h"
#include "base/logging.h"
#include "base/thread_annotations.h"
#include "build/build_config.h"

#if !BUILDFLAG(IS_NACL)
#include "base/debug/crash_logging.h"
#endif  // !BUILDFLAG(IS_NACL)

#include <atomic>

namespace logging {

namespace {

// TODO(crbug.com/851128): Once landed this needs to be under
// BUILDFLAG(DCHECK_IS_CONFIGURABLE) and NotReachedLogMessage cleaned up and
// instead just be a LogMessage using FATAL.
void DumpOnceWithoutCrashing(LogMessage* log_message) {
  // Best-effort gate to prevent multiple DCHECKs from being dumped. This will
  // race if multiple threads DCHECK at the same time, but we'll eventually stop
  // reporting and at most report once per thread.
  static std::atomic<bool> has_dumped = false;
  if (!has_dumped.load(std::memory_order_relaxed)) {
    // Copy the LogMessage message to stack memory to make sure it can be
    // recovered in crash dumps.
    // TODO(pbos): Do we need this for NACL builds or is the crash key set in
    // the caller sufficient?
    DEBUG_ALIAS_FOR_CSTR(log_message_str,
                         log_message->BuildCrashString().c_str(), 1024);

    // Note that dumping may fail if the crash handler hasn't been set yet. In
    // that case we want to try again on the next failing DCHECK.
    if (base::debug::DumpWithoutCrashingUnthrottled()) {
      has_dumped.store(true, std::memory_order_relaxed);
    }
  }
}

void NotReachedDumpOnceWithoutCrashing(LogMessage* log_message) {
#if !BUILDFLAG(IS_NACL)
  SCOPED_CRASH_KEY_STRING1024("Logging", "NOTREACHED_MESSAGE",
                              log_message->BuildCrashString());
#endif  // !BUILDFLAG(IS_NACL)
  DumpOnceWithoutCrashing(log_message);
}

class NotReachedLogMessage : public LogMessage {
 public:
  using LogMessage::LogMessage;
  ~NotReachedLogMessage() override {
    if (severity() != logging::LOGGING_FATAL) {
      NotReachedDumpOnceWithoutCrashing(this);
    }
  }
};

#if BUILDFLAG(DCHECK_IS_CONFIGURABLE)

void DCheckDumpOnceWithoutCrashing(LogMessage* log_message) {
#if !BUILDFLAG(IS_NACL)
  SCOPED_CRASH_KEY_STRING1024("Logging", "DCHECK_MESSAGE",
                              log_message->BuildCrashString());
#endif  // !BUILDFLAG(IS_NACL)
  DumpOnceWithoutCrashing(log_message);
}

class DCheckLogMessage : public LogMessage {
 public:
  using LogMessage::LogMessage;
  ~DCheckLogMessage() override {
    if (severity() != logging::LOGGING_FATAL) {
      DCheckDumpOnceWithoutCrashing(this);
    }
  }
};

#if BUILDFLAG(IS_WIN)
class DCheckWin32ErrorLogMessage : public Win32ErrorLogMessage {
 public:
  using Win32ErrorLogMessage::Win32ErrorLogMessage;
  ~DCheckWin32ErrorLogMessage() override {
    if (severity() != logging::LOGGING_FATAL) {
      DCheckDumpOnceWithoutCrashing(this);
    }
  }
};
#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
class DCheckErrnoLogMessage : public ErrnoLogMessage {
 public:
  using ErrnoLogMessage::ErrnoLogMessage;
  ~DCheckErrnoLogMessage() override {
    if (severity() != logging::LOGGING_FATAL) {
      DCheckDumpOnceWithoutCrashing(this);
    }
  }
};
#endif  // BUILDFLAG(IS_WIN)
#else
static_assert(logging::LOGGING_DCHECK == logging::LOGGING_FATAL);
using DCheckLogMessage = LogMessage;
#if BUILDFLAG(IS_WIN)
using DCheckWin32ErrorLogMessage = Win32ErrorLogMessage;
#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
using DCheckErrnoLogMessage = ErrnoLogMessage;
#endif  // BUILDFLAG(IS_WIN)
#endif  // BUILDFLAG(DCHECK_IS_CONFIGURABLE)

}  // namespace

CheckError CheckError::Check(const char* file,
                             int line,
                             const char* condition) {
  auto* const log_message = new LogMessage(file, line, LOGGING_FATAL);
  log_message->stream() << "Check failed: " << condition << ". ";
  return CheckError(log_message);
}

CheckError CheckError::DCheck(const char* file,
                              int line,
                              const char* condition) {
  auto* const log_message = new DCheckLogMessage(file, line, LOGGING_DCHECK);
  log_message->stream() << "Check failed: " << condition << ". ";
  return CheckError(log_message);
}

CheckError CheckError::PCheck(const char* file,
                              int line,
                              const char* condition) {
  SystemErrorCode err_code = logging::GetLastSystemErrorCode();
#if BUILDFLAG(IS_WIN)
  auto* const log_message =
      new Win32ErrorLogMessage(file, line, LOGGING_FATAL, err_code);
#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
  auto* const log_message =
      new ErrnoLogMessage(file, line, LOGGING_FATAL, err_code);
#endif
  log_message->stream() << "Check failed: " << condition << ". ";
  return CheckError(log_message);
}

CheckError CheckError::PCheck(const char* file, int line) {
  return PCheck(file, line, "");
}

CheckError CheckError::DPCheck(const char* file,
                               int line,
                               const char* condition) {
  SystemErrorCode err_code = logging::GetLastSystemErrorCode();
#if BUILDFLAG(IS_WIN)
  auto* const log_message =
      new DCheckWin32ErrorLogMessage(file, line, LOGGING_DCHECK, err_code);
#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
  auto* const log_message =
      new DCheckErrnoLogMessage(file, line, LOGGING_DCHECK, err_code);
#endif
  log_message->stream() << "Check failed: " << condition << ". ";
  return CheckError(log_message);
}

CheckError CheckError::NotImplemented(const char* file,
                                      int line,
                                      const char* function) {
  auto* const log_message = new LogMessage(file, line, LOGGING_ERROR);
  log_message->stream() << "Not implemented reached in " << function;
  return CheckError(log_message);
}

std::ostream& CheckError::stream() {
  return log_message_->stream();
}

CheckError::~CheckError() {
  // TODO(crbug.com/1409729): Consider splitting out CHECK from DCHECK so that
  // the destructor can be marked [[noreturn]] and we don't need to check
  // severity in the destructor.
  const bool is_fatal = log_message_->severity() == LOGGING_FATAL;
  // Note: This function ends up in crash stack traces. If its full name
  // changes, the crash server's magic signature logic needs to be updated.
  // See cl/306632920.
  delete log_message_;

  // Make sure we crash even if LOG(FATAL) has been overridden.
  // TODO(crbug.com/1409729): Remove severity checking in the destructor when
  // LOG(FATAL) is [[noreturn]] and can't be overridden.
  if (is_fatal) {
    base::ImmediateCrash();
  }
}

NotReachedError NotReachedError::NotReached(const char* file, int line) {
  // Outside DCHECK builds NOTREACHED() should not be FATAL. For now.
  const LogSeverity severity = DCHECK_IS_ON() ? LOGGING_DCHECK : LOGGING_ERROR;
  auto* const log_message = new NotReachedLogMessage(file, line, severity);

  // TODO(pbos): Consider a better message for NotReached(), this is here to
  // match existing behavior + test expectations.
  log_message->stream() << "Check failed: false. ";
  return NotReachedError(log_message);
}

void NotReachedError::TriggerNotReached() {
  // This triggers a NOTREACHED() error as the returned NotReachedError goes out
  // of scope.
  NotReached("", -1);
}

NotReachedError::~NotReachedError() = default;

NotReachedNoreturnError::NotReachedNoreturnError(const char* file, int line)
    : CheckError([file, line]() {
        auto* const log_message = new LogMessage(file, line, LOGGING_FATAL);
        log_message->stream() << "NOTREACHED hit. ";
        return log_message;
      }()) {}

// Note: This function ends up in crash stack traces. If its full name changes,
// the crash server's magic signature logic needs to be updated. See
// cl/306632920.
NotReachedNoreturnError::~NotReachedNoreturnError() {
  delete log_message_;

  // Make sure we die if we haven't. LOG(FATAL) is not yet [[noreturn]] as of
  // writing this.
  base::ImmediateCrash();
}

LogMessage* CheckOpResult::CreateLogMessage(bool is_dcheck,
                                            const char* file,
                                            int line,
                                            const char* expr_str,
                                            char* v1_str,
                                            char* v2_str) {
  LogMessage* const log_message =
      is_dcheck ? new DCheckLogMessage(file, line, LOGGING_DCHECK)
                : new LogMessage(file, line, LOGGING_FATAL);
  log_message->stream() << "Check failed: " << expr_str << " (" << v1_str
                        << " vs. " << v2_str << ")";
  free(v1_str);
  free(v2_str);
  return log_message;
}

void RawCheck(const char* message) {
  RawLog(LOGGING_FATAL, message);
}

void RawError(const char* message) {
  RawLog(LOGGING_ERROR, message);
}

}  // namespace logging