engine/src/flutter/fml/logging.cc

// Copyright 2013 The Flutter 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 <cstring>
#include <iostream>

#include "flutter/fml/build_config.h"
#include "flutter/fml/log_level.h"
#include "flutter/fml/log_settings.h"
#include "flutter/fml/logging.h"

#if defined(FML_OS_ANDROID)
#include <android/log.h>
#elif defined(FML_OS_IOS)
#include <syslog.h>
#elif defined(OS_FUCHSIA)
#include <lib/syslog/cpp/log_message_impl.h>
#include <lib/syslog/structured_backend/cpp/log_buffer.h>
#include <lib/syslog/structured_backend/fuchsia_syslog.h>
#include <zircon/process.h>
#include <zircon/syscalls.h>
#include <zircon/syscalls/object.h>
#endif

namespace fml {

namespace {

#if !defined(OS_FUCHSIA)
const char* const kLogSeverityNames[kLogNumSeverities] = {
    "INFO", "WARNING", "ERROR", "IMPORTANT", "FATAL"};

const char* GetNameForLogSeverity(LogSeverity severity) {
  if (severity >= kLogInfo && severity < kLogNumSeverities) {
    return kLogSeverityNames[severity];
  }
  return "UNKNOWN";
}
#endif

const char* StripDots(const char* path) {
  while (strncmp(path, "../", 3) == 0) {
    path += 3;
  }
  return path;
}

#if defined(OS_FUCHSIA)

const std::string* GetProcessName() {
  static const std::string* process_name = []() -> const std::string* {
    char name[ZX_MAX_NAME_LEN];
    zx_status_t status = zx_object_get_property(zx_process_self(), ZX_PROP_NAME,
                                                name, sizeof(name));
    if (status != ZX_OK) {
      return nullptr;
    }
    return new std::string(name);
  }();
  return process_name;
}

#endif

}  // namespace

LogMessage::LogMessage(LogSeverity severity,
                       const char* file,
                       int line,
                       const char* condition)
    : severity_(severity), file_(StripDots(file)), line_(line) {
#if !defined(OS_FUCHSIA)
  stream_ << "[";
  if (severity >= kLogInfo) {
    stream_ << GetNameForLogSeverity(severity);
  } else {
    stream_ << "VERBOSE" << -severity;
  }
  stream_ << ":" << file_ << "(" << line_ << ")] ";
#endif

  if (condition) {
    stream_ << "Check failed: " << condition << ". ";
  }
}

// static
thread_local std::ostringstream* LogMessage::capture_next_log_stream_ = nullptr;

namespace testing {

LogCapture::LogCapture() {
  fml::LogMessage::CaptureNextLog(&stream_);
}

LogCapture::~LogCapture() {
  fml::LogMessage::CaptureNextLog(nullptr);
}

std::string LogCapture::str() const {
  return stream_.str();
}

}  // namespace testing

// static
void LogMessage::CaptureNextLog(std::ostringstream* stream) {
  LogMessage::capture_next_log_stream_ = stream;
}

LogMessage::~LogMessage() {
#if !defined(OS_FUCHSIA)
  stream_ << std::endl;
#endif
  if (capture_next_log_stream_) {
    *capture_next_log_stream_ << stream_.str();
    capture_next_log_stream_ = nullptr;
  } else {
#if defined(FML_OS_ANDROID)
    android_LogPriority priority =
        (severity_ < 0) ? ANDROID_LOG_VERBOSE : ANDROID_LOG_UNKNOWN;
    switch (severity_) {
      case kLogImportant:
      case kLogInfo:
        priority = ANDROID_LOG_INFO;
        break;
      case kLogWarning:
        priority = ANDROID_LOG_WARN;
        break;
      case kLogError:
        priority = ANDROID_LOG_ERROR;
        break;
      case kLogFatal:
        priority = ANDROID_LOG_FATAL;
        break;
    }
    __android_log_write(priority, "flutter", stream_.str().c_str());
#elif defined(FML_OS_IOS)
    syslog(LOG_ALERT, "%s", stream_.str().c_str());
#elif defined(OS_FUCHSIA)
    FuchsiaLogSeverity severity;
    switch (severity_) {
      case kLogImportant:
      case kLogInfo:
        severity = FUCHSIA_LOG_INFO;
        break;
      case kLogWarning:
        severity = FUCHSIA_LOG_WARNING;
        break;
      case kLogError:
        severity = FUCHSIA_LOG_ERROR;
        break;
      case kLogFatal:
        severity = FUCHSIA_LOG_FATAL;
        break;
      default:
        if (severity_ < 0) {
          severity = FUCHSIA_LOG_DEBUG;
        } else {
          // Unknown severity. Use INFO.
          severity = FUCHSIA_LOG_INFO;
        }
        break;
    }
    fuchsia_logging::LogBuffer buffer =
        fuchsia_logging::LogBufferBuilder(severity)
            .WithFile(file_, line_)
            .WithMsg(stream_.str())
            .Build();
    const std::string* process_name = GetProcessName();
    if (process_name) {
      buffer.WriteKeyValue("tag", *process_name);
    }
    [[maybe_unused]] zx::result result =
        fuchsia_logging::FlushToGlobalLogger(buffer);
#else
    // Don't use std::cerr here, because it may not be initialized properly yet.
    fprintf(stderr, "%s", stream_.str().c_str());
    fflush(stderr);
#endif
  }

  if (severity_ >= kLogFatal) {
    KillProcess();
  }
}

int GetVlogVerbosity() {
  return std::max(-1, kLogInfo - GetMinLogLevel());
}

bool ShouldCreateLogMessage(LogSeverity severity) {
  return severity >= GetMinLogLevel();
}

void KillProcess() {
  abort();
}

}  // namespace fml