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      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "base/logging.h"
      6 
      7 #include <limits.h>
      8 #include <stdint.h>
      9 
     10 #include "base/debug/activity_tracker.h"
     11 #include "base/macros.h"
     12 #include "build/build_config.h"
     13 
     14 #if defined(OS_WIN)
     15 #include <io.h>
     16 typedef HANDLE FileHandle;
     17 typedef HANDLE MutexHandle;
     18 // Windows warns on using write().  It prefers _write().
     19 #define write(fd, buf, count) _write(fd, buf, static_cast<unsigned int>(count))
     20 // Windows doesn't define STDERR_FILENO.  Define it here.
     21 #define STDERR_FILENO 2
     22 #elif defined(OS_MACOSX)
     23 #include <asl.h>
     24 #include <CoreFoundation/CoreFoundation.h>
     25 #include <mach/mach.h>
     26 #include <mach/mach_time.h>
     27 #include <mach-o/dyld.h>
     28 #elif defined(OS_POSIX)
     29 #if defined(OS_NACL)
     30 #include <sys/time.h>  // timespec doesn't seem to be in <time.h>
     31 #endif
     32 #include <time.h>
     33 #endif
     34 
     35 #if defined(OS_POSIX)
     36 #include <errno.h>
     37 #include <paths.h>
     38 #include <pthread.h>
     39 #include <stdio.h>
     40 #include <stdlib.h>
     41 #include <string.h>
     42 #include <sys/stat.h>
     43 #include <unistd.h>
     44 #define MAX_PATH PATH_MAX
     45 typedef FILE* FileHandle;
     46 typedef pthread_mutex_t* MutexHandle;
     47 #endif
     48 
     49 #include <algorithm>
     50 #include <cstring>
     51 #include <ctime>
     52 #include <iomanip>
     53 #include <ostream>
     54 #include <string>
     55 
     56 #include "base/base_switches.h"
     57 #include "base/command_line.h"
     58 #include "base/debug/alias.h"
     59 #include "base/debug/debugger.h"
     60 #include "base/debug/stack_trace.h"
     61 #include "base/posix/eintr_wrapper.h"
     62 #include "base/strings/string_piece.h"
     63 #include "base/strings/string_util.h"
     64 #include "base/strings/stringprintf.h"
     65 #include "base/strings/sys_string_conversions.h"
     66 #include "base/strings/utf_string_conversions.h"
     67 #include "base/synchronization/lock_impl.h"
     68 #include "base/threading/platform_thread.h"
     69 #include "base/vlog.h"
     70 #if defined(OS_POSIX)
     71 #include "base/posix/safe_strerror.h"
     72 #endif
     73 
     74 #if !defined(OS_ANDROID)
     75 #include "base/files/file_path.h"
     76 #endif
     77 
     78 #if defined(OS_ANDROID) || defined(__ANDROID__)
     79 #include <android/log.h>
     80 #endif
     81 
     82 namespace logging {
     83 
     84 namespace {
     85 
     86 VlogInfo* g_vlog_info = nullptr;
     87 VlogInfo* g_vlog_info_prev = nullptr;
     88 
     89 const char* const log_severity_names[LOG_NUM_SEVERITIES] = {
     90   "INFO", "WARNING", "ERROR", "FATAL" };
     91 
     92 const char* log_severity_name(int severity) {
     93   if (severity >= 0 && severity < LOG_NUM_SEVERITIES)
     94     return log_severity_names[severity];
     95   return "UNKNOWN";
     96 }
     97 
     98 int g_min_log_level = 0;
     99 
    100 LoggingDestination g_logging_destination = LOG_DEFAULT;
    101 
    102 // For LOG_ERROR and above, always print to stderr.
    103 const int kAlwaysPrintErrorLevel = LOG_ERROR;
    104 
    105 // Which log file to use? This is initialized by InitLogging or
    106 // will be lazily initialized to the default value when it is
    107 // first needed.
    108 #if defined(OS_WIN)
    109 typedef std::wstring PathString;
    110 #else
    111 typedef std::string PathString;
    112 #endif
    113 PathString* g_log_file_name = nullptr;
    114 
    115 // This file is lazily opened and the handle may be nullptr
    116 FileHandle g_log_file = nullptr;
    117 
    118 // What should be prepended to each message?
    119 bool g_log_process_id = false;
    120 bool g_log_thread_id = false;
    121 bool g_log_timestamp = true;
    122 bool g_log_tickcount = false;
    123 
    124 // Should we pop up fatal debug messages in a dialog?
    125 bool show_error_dialogs = false;
    126 
    127 // An assert handler override specified by the client to be called instead of
    128 // the debug message dialog and process termination.
    129 LogAssertHandlerFunction log_assert_handler = nullptr;
    130 // A log message handler that gets notified of every log message we process.
    131 LogMessageHandlerFunction log_message_handler = nullptr;
    132 
    133 // Helper functions to wrap platform differences.
    134 
    135 int32_t CurrentProcessId() {
    136 #if defined(OS_WIN)
    137   return GetCurrentProcessId();
    138 #elif defined(OS_POSIX)
    139   return getpid();
    140 #endif
    141 }
    142 
    143 uint64_t TickCount() {
    144 #if defined(OS_WIN)
    145   return GetTickCount();
    146 #elif defined(OS_MACOSX)
    147   return mach_absolute_time();
    148 #elif defined(OS_NACL)
    149   // NaCl sadly does not have _POSIX_TIMERS enabled in sys/features.h
    150   // So we have to use clock() for now.
    151   return clock();
    152 #elif defined(OS_POSIX)
    153   struct timespec ts;
    154   clock_gettime(CLOCK_MONOTONIC, &ts);
    155 
    156   uint64_t absolute_micro = static_cast<int64_t>(ts.tv_sec) * 1000000 +
    157                             static_cast<int64_t>(ts.tv_nsec) / 1000;
    158 
    159   return absolute_micro;
    160 #endif
    161 }
    162 
    163 void DeleteFilePath(const PathString& log_name) {
    164 #if defined(OS_WIN)
    165   DeleteFile(log_name.c_str());
    166 #elif defined(OS_NACL)
    167   // Do nothing; unlink() isn't supported on NaCl.
    168 #else
    169   unlink(log_name.c_str());
    170 #endif
    171 }
    172 
    173 PathString GetDefaultLogFile() {
    174 #if defined(OS_WIN)
    175   // On Windows we use the same path as the exe.
    176   wchar_t module_name[MAX_PATH];
    177   GetModuleFileName(nullptr, module_name, MAX_PATH);
    178 
    179   PathString log_name = module_name;
    180   PathString::size_type last_backslash = log_name.rfind('\\', log_name.size());
    181   if (last_backslash != PathString::npos)
    182     log_name.erase(last_backslash + 1);
    183   log_name += L"debug.log";
    184   return log_name;
    185 #elif defined(OS_POSIX)
    186   // On other platforms we just use the current directory.
    187   return PathString("debug.log");
    188 #endif
    189 }
    190 
    191 // We don't need locks on Windows for atomically appending to files. The OS
    192 // provides this functionality.
    193 #if !defined(OS_WIN)
    194 // This class acts as a wrapper for locking the logging files.
    195 // LoggingLock::Init() should be called from the main thread before any logging
    196 // is done. Then whenever logging, be sure to have a local LoggingLock
    197 // instance on the stack. This will ensure that the lock is unlocked upon
    198 // exiting the frame.
    199 // LoggingLocks can not be nested.
    200 class LoggingLock {
    201  public:
    202   LoggingLock() {
    203     LockLogging();
    204   }
    205 
    206   ~LoggingLock() {
    207     UnlockLogging();
    208   }
    209 
    210   static void Init(LogLockingState lock_log, const PathChar* new_log_file) {
    211     if (initialized)
    212       return;
    213     lock_log_file = lock_log;
    214 
    215     if (lock_log_file != LOCK_LOG_FILE)
    216       log_lock = new base::internal::LockImpl();
    217 
    218     initialized = true;
    219   }
    220 
    221  private:
    222   static void LockLogging() {
    223     if (lock_log_file == LOCK_LOG_FILE) {
    224 #if defined(OS_POSIX)
    225       pthread_mutex_lock(&log_mutex);
    226 #endif
    227     } else {
    228       // use the lock
    229       log_lock->Lock();
    230     }
    231   }
    232 
    233   static void UnlockLogging() {
    234     if (lock_log_file == LOCK_LOG_FILE) {
    235 #if defined(OS_POSIX)
    236       pthread_mutex_unlock(&log_mutex);
    237 #endif
    238     } else {
    239       log_lock->Unlock();
    240     }
    241   }
    242 
    243   // The lock is used if log file locking is false. It helps us avoid problems
    244   // with multiple threads writing to the log file at the same time.  Use
    245   // LockImpl directly instead of using Lock, because Lock makes logging calls.
    246   static base::internal::LockImpl* log_lock;
    247 
    248   // When we don't use a lock, we are using a global mutex. We need to do this
    249   // because LockFileEx is not thread safe.
    250 #if defined(OS_POSIX)
    251   static pthread_mutex_t log_mutex;
    252 #endif
    253 
    254   static bool initialized;
    255   static LogLockingState lock_log_file;
    256 };
    257 
    258 // static
    259 bool LoggingLock::initialized = false;
    260 // static
    261 base::internal::LockImpl* LoggingLock::log_lock = nullptr;
    262 // static
    263 LogLockingState LoggingLock::lock_log_file = LOCK_LOG_FILE;
    264 
    265 #if defined(OS_POSIX)
    266 pthread_mutex_t LoggingLock::log_mutex = PTHREAD_MUTEX_INITIALIZER;
    267 #endif
    268 
    269 #endif  // OS_WIN
    270 
    271 // Called by logging functions to ensure that |g_log_file| is initialized
    272 // and can be used for writing. Returns false if the file could not be
    273 // initialized. |g_log_file| will be nullptr in this case.
    274 bool InitializeLogFileHandle() {
    275   if (g_log_file)
    276     return true;
    277 
    278   if (!g_log_file_name) {
    279     // Nobody has called InitLogging to specify a debug log file, so here we
    280     // initialize the log file name to a default.
    281     g_log_file_name = new PathString(GetDefaultLogFile());
    282   }
    283 
    284   if ((g_logging_destination & LOG_TO_FILE) != 0) {
    285 #if defined(OS_WIN)
    286     // The FILE_APPEND_DATA access mask ensures that the file is atomically
    287     // appended to across accesses from multiple threads.
    288     // https://msdn.microsoft.com/en-us/library/windows/desktop/aa364399(v=vs.85).aspx
    289     // https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858(v=vs.85).aspx
    290     g_log_file = CreateFile(g_log_file_name->c_str(), FILE_APPEND_DATA,
    291                             FILE_SHARE_READ | FILE_SHARE_WRITE, nullptr,
    292                             OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, nullptr);
    293     if (g_log_file == INVALID_HANDLE_VALUE || g_log_file == nullptr) {
    294       // We are intentionally not using FilePath or FileUtil here to reduce the
    295       // dependencies of the logging implementation. For e.g. FilePath and
    296       // FileUtil depend on shell32 and user32.dll. This is not acceptable for
    297       // some consumers of base logging like chrome_elf, etc.
    298       // Please don't change the code below to use FilePath.
    299       // try the current directory
    300       wchar_t system_buffer[MAX_PATH];
    301       system_buffer[0] = 0;
    302       DWORD len = ::GetCurrentDirectory(arraysize(system_buffer),
    303                                         system_buffer);
    304       if (len == 0 || len > arraysize(system_buffer))
    305         return false;
    306 
    307       *g_log_file_name = system_buffer;
    308       // Append a trailing backslash if needed.
    309       if (g_log_file_name->back() != L'\\')
    310         *g_log_file_name += L"\\";
    311       *g_log_file_name += L"debug.log";
    312 
    313       g_log_file = CreateFile(g_log_file_name->c_str(), FILE_APPEND_DATA,
    314                               FILE_SHARE_READ | FILE_SHARE_WRITE, nullptr,
    315                               OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, nullptr);
    316       if (g_log_file == INVALID_HANDLE_VALUE || g_log_file == nullptr) {
    317         g_log_file = nullptr;
    318         return false;
    319       }
    320     }
    321 #elif defined(OS_POSIX)
    322     g_log_file = fopen(g_log_file_name->c_str(), "a");
    323     if (g_log_file == nullptr)
    324       return false;
    325 #endif
    326   }
    327 
    328   return true;
    329 }
    330 
    331 void CloseFile(FileHandle log) {
    332 #if defined(OS_WIN)
    333   CloseHandle(log);
    334 #else
    335   fclose(log);
    336 #endif
    337 }
    338 
    339 void CloseLogFileUnlocked() {
    340   if (!g_log_file)
    341     return;
    342 
    343   CloseFile(g_log_file);
    344   g_log_file = nullptr;
    345 }
    346 
    347 }  // namespace
    348 
    349 // This is never instantiated, it's just used for EAT_STREAM_PARAMETERS to have
    350 // an object of the correct type on the LHS of the unused part of the ternary
    351 // operator.
    352 std::ostream* g_swallow_stream;
    353 
    354 LoggingSettings::LoggingSettings()
    355     : logging_dest(LOG_DEFAULT),
    356       log_file(nullptr),
    357       lock_log(LOCK_LOG_FILE),
    358       delete_old(APPEND_TO_OLD_LOG_FILE) {}
    359 
    360 bool BaseInitLoggingImpl(const LoggingSettings& settings) {
    361 #if defined(OS_NACL)
    362   // Can log only to the system debug log.
    363   CHECK_EQ(settings.logging_dest & ~LOG_TO_SYSTEM_DEBUG_LOG, 0);
    364 #endif
    365   if (base::CommandLine::InitializedForCurrentProcess()) {
    366     base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
    367     // Don't bother initializing |g_vlog_info| unless we use one of the
    368     // vlog switches.
    369     if (command_line->HasSwitch(switches::kV) ||
    370         command_line->HasSwitch(switches::kVModule)) {
    371       // NOTE: If |g_vlog_info| has already been initialized, it might be in use
    372       // by another thread. Don't delete the old VLogInfo, just create a second
    373       // one. We keep track of both to avoid memory leak warnings.
    374       CHECK(!g_vlog_info_prev);
    375       g_vlog_info_prev = g_vlog_info;
    376 
    377       g_vlog_info =
    378           new VlogInfo(command_line->GetSwitchValueASCII(switches::kV),
    379                        command_line->GetSwitchValueASCII(switches::kVModule),
    380                        &g_min_log_level);
    381     }
    382   }
    383 
    384   g_logging_destination = settings.logging_dest;
    385 
    386   // ignore file options unless logging to file is set.
    387   if ((g_logging_destination & LOG_TO_FILE) == 0)
    388     return true;
    389 
    390 #if !defined(OS_WIN)
    391   LoggingLock::Init(settings.lock_log, settings.log_file);
    392   LoggingLock logging_lock;
    393 #endif
    394 
    395   // Calling InitLogging twice or after some log call has already opened the
    396   // default log file will re-initialize to the new options.
    397   CloseLogFileUnlocked();
    398 
    399   if (!g_log_file_name)
    400     g_log_file_name = new PathString();
    401   *g_log_file_name = settings.log_file;
    402   if (settings.delete_old == DELETE_OLD_LOG_FILE)
    403     DeleteFilePath(*g_log_file_name);
    404 
    405   return InitializeLogFileHandle();
    406 }
    407 
    408 void SetMinLogLevel(int level) {
    409   g_min_log_level = std::min(LOG_FATAL, level);
    410 }
    411 
    412 int GetMinLogLevel() {
    413   return g_min_log_level;
    414 }
    415 
    416 bool ShouldCreateLogMessage(int severity) {
    417   if (severity < g_min_log_level)
    418     return false;
    419 
    420   // Return true here unless we know ~LogMessage won't do anything. Note that
    421   // ~LogMessage writes to stderr if severity_ >= kAlwaysPrintErrorLevel, even
    422   // when g_logging_destination is LOG_NONE.
    423   return g_logging_destination != LOG_NONE || log_message_handler ||
    424          severity >= kAlwaysPrintErrorLevel;
    425 }
    426 
    427 int GetVlogVerbosity() {
    428   return std::max(-1, LOG_INFO - GetMinLogLevel());
    429 }
    430 
    431 int GetVlogLevelHelper(const char* file, size_t N) {
    432   DCHECK_GT(N, 0U);
    433   // Note: |g_vlog_info| may change on a different thread during startup
    434   // (but will always be valid or nullptr).
    435   VlogInfo* vlog_info = g_vlog_info;
    436   return vlog_info ?
    437       vlog_info->GetVlogLevel(base::StringPiece(file, N - 1)) :
    438       GetVlogVerbosity();
    439 }
    440 
    441 void SetLogItems(bool enable_process_id, bool enable_thread_id,
    442                  bool enable_timestamp, bool enable_tickcount) {
    443   g_log_process_id = enable_process_id;
    444   g_log_thread_id = enable_thread_id;
    445   g_log_timestamp = enable_timestamp;
    446   g_log_tickcount = enable_tickcount;
    447 }
    448 
    449 void SetShowErrorDialogs(bool enable_dialogs) {
    450   show_error_dialogs = enable_dialogs;
    451 }
    452 
    453 void SetLogAssertHandler(LogAssertHandlerFunction handler) {
    454   log_assert_handler = handler;
    455 }
    456 
    457 void SetLogMessageHandler(LogMessageHandlerFunction handler) {
    458   log_message_handler = handler;
    459 }
    460 
    461 LogMessageHandlerFunction GetLogMessageHandler() {
    462   return log_message_handler;
    463 }
    464 
    465 // Explicit instantiations for commonly used comparisons.
    466 template std::string* MakeCheckOpString<int, int>(
    467     const int&, const int&, const char* names);
    468 template std::string* MakeCheckOpString<unsigned long, unsigned long>(
    469     const unsigned long&, const unsigned long&, const char* names);
    470 template std::string* MakeCheckOpString<unsigned long, unsigned int>(
    471     const unsigned long&, const unsigned int&, const char* names);
    472 template std::string* MakeCheckOpString<unsigned int, unsigned long>(
    473     const unsigned int&, const unsigned long&, const char* names);
    474 template std::string* MakeCheckOpString<std::string, std::string>(
    475     const std::string&, const std::string&, const char* name);
    476 
    477 void MakeCheckOpValueString(std::ostream* os, std::nullptr_t p) {
    478   (*os) << "nullptr";
    479 }
    480 
    481 #if !defined(NDEBUG)
    482 // Displays a message box to the user with the error message in it.
    483 // Used for fatal messages, where we close the app simultaneously.
    484 // This is for developers only; we don't use this in circumstances
    485 // (like release builds) where users could see it, since users don't
    486 // understand these messages anyway.
    487 void DisplayDebugMessageInDialog(const std::string& str) {
    488   if (str.empty())
    489     return;
    490 
    491   if (!show_error_dialogs)
    492     return;
    493 
    494 #if defined(OS_WIN)
    495   MessageBoxW(nullptr, base::UTF8ToUTF16(str).c_str(), L"Fatal error",
    496               MB_OK | MB_ICONHAND | MB_TOPMOST);
    497 #else
    498   // We intentionally don't implement a dialog on other platforms.
    499   // You can just look at stderr.
    500 #endif  // defined(OS_WIN)
    501 }
    502 #endif  // !defined(NDEBUG)
    503 
    504 #if defined(OS_WIN)
    505 LogMessage::SaveLastError::SaveLastError() : last_error_(::GetLastError()) {
    506 }
    507 
    508 LogMessage::SaveLastError::~SaveLastError() {
    509   ::SetLastError(last_error_);
    510 }
    511 #endif  // defined(OS_WIN)
    512 
    513 LogMessage::LogMessage(const char* file, int line, LogSeverity severity)
    514     : severity_(severity), file_(file), line_(line) {
    515   Init(file, line);
    516 }
    517 
    518 LogMessage::LogMessage(const char* file, int line, const char* condition)
    519     : severity_(LOG_FATAL), file_(file), line_(line) {
    520   Init(file, line);
    521   stream_ << "Check failed: " << condition << ". ";
    522 }
    523 
    524 LogMessage::LogMessage(const char* file, int line, std::string* result)
    525     : severity_(LOG_FATAL), file_(file), line_(line) {
    526   Init(file, line);
    527   stream_ << "Check failed: " << *result;
    528   delete result;
    529 }
    530 
    531 LogMessage::LogMessage(const char* file, int line, LogSeverity severity,
    532                        std::string* result)
    533     : severity_(severity), file_(file), line_(line) {
    534   Init(file, line);
    535   stream_ << "Check failed: " << *result;
    536   delete result;
    537 }
    538 
    539 LogMessage::~LogMessage() {
    540 #if !defined(OFFICIAL_BUILD) && !defined(OS_NACL) && !defined(__UCLIBC__)
    541   if (severity_ == LOG_FATAL && !base::debug::BeingDebugged()) {
    542     // Include a stack trace on a fatal, unless a debugger is attached.
    543     base::debug::StackTrace trace;
    544     stream_ << std::endl;  // Newline to separate from log message.
    545     trace.OutputToStream(&stream_);
    546   }
    547 #endif
    548   stream_ << std::endl;
    549   std::string str_newline(stream_.str());
    550 
    551   // Give any log message handler first dibs on the message.
    552   if (log_message_handler &&
    553       log_message_handler(severity_, file_, line_,
    554                           message_start_, str_newline)) {
    555     // The handler took care of it, no further processing.
    556     return;
    557   }
    558 
    559   if ((g_logging_destination & LOG_TO_SYSTEM_DEBUG_LOG) != 0) {
    560 #if defined(OS_WIN)
    561     OutputDebugStringA(str_newline.c_str());
    562 #elif defined(OS_MACOSX)
    563     // In LOG_TO_SYSTEM_DEBUG_LOG mode, log messages are always written to
    564     // stderr. If stderr is /dev/null, also log via ASL (Apple System Log). If
    565     // there's something weird about stderr, assume that log messages are going
    566     // nowhere and log via ASL too. Messages logged via ASL show up in
    567     // Console.app.
    568     //
    569     // Programs started by launchd, as UI applications normally are, have had
    570     // stderr connected to /dev/null since OS X 10.8. Prior to that, stderr was
    571     // a pipe to launchd, which logged what it received (see log_redirect_fd in
    572     // 10.7.5 launchd-392.39/launchd/src/launchd_core_logic.c).
    573     //
    574     // Another alternative would be to determine whether stderr is a pipe to
    575     // launchd and avoid logging via ASL only in that case. See 10.7.5
    576     // CF-635.21/CFUtilities.c also_do_stderr(). This would result in logging to
    577     // both stderr and ASL even in tests, where it's undesirable to log to the
    578     // system log at all.
    579     //
    580     // Note that the ASL client by default discards messages whose levels are
    581     // below ASL_LEVEL_NOTICE. It's possible to change that with
    582     // asl_set_filter(), but this is pointless because syslogd normally applies
    583     // the same filter.
    584     const bool log_via_asl = []() {
    585       struct stat stderr_stat;
    586       if (fstat(fileno(stderr), &stderr_stat) == -1) {
    587         return true;
    588       }
    589       if (!S_ISCHR(stderr_stat.st_mode)) {
    590         return false;
    591       }
    592 
    593       struct stat dev_null_stat;
    594       if (stat(_PATH_DEVNULL, &dev_null_stat) == -1) {
    595         return true;
    596       }
    597 
    598       return !S_ISCHR(dev_null_stat.st_mode) ||
    599              stderr_stat.st_rdev == dev_null_stat.st_rdev;
    600     }();
    601 
    602     if (log_via_asl) {
    603       // Log roughly the same way that CFLog() and NSLog() would. See 10.10.5
    604       // CF-1153.18/CFUtilities.c __CFLogCString().
    605       //
    606       // The ASL facility is set to the main bundle ID if available. Otherwise,
    607       // "com.apple.console" is used.
    608       CFBundleRef main_bundle = CFBundleGetMainBundle();
    609       CFStringRef main_bundle_id_cf =
    610           main_bundle ? CFBundleGetIdentifier(main_bundle) : nullptr;
    611       std::string asl_facility =
    612           main_bundle_id_cf ? base::SysCFStringRefToUTF8(main_bundle_id_cf)
    613                             : std::string("com.apple.console");
    614 
    615       class ASLClient {
    616        public:
    617         explicit ASLClient(const std::string& asl_facility)
    618             : client_(asl_open(nullptr,
    619                                asl_facility.c_str(),
    620                                ASL_OPT_NO_DELAY)) {}
    621         ~ASLClient() { asl_close(client_); }
    622 
    623         aslclient get() const { return client_; }
    624 
    625        private:
    626         aslclient client_;
    627         DISALLOW_COPY_AND_ASSIGN(ASLClient);
    628       } asl_client(asl_facility);
    629 
    630       class ASLMessage {
    631        public:
    632         ASLMessage() : message_(asl_new(ASL_TYPE_MSG)) {}
    633         ~ASLMessage() { asl_free(message_); }
    634 
    635         aslmsg get() const { return message_; }
    636 
    637        private:
    638         aslmsg message_;
    639         DISALLOW_COPY_AND_ASSIGN(ASLMessage);
    640       } asl_message;
    641 
    642       // By default, messages are only readable by the admin group. Explicitly
    643       // make them readable by the user generating the messages.
    644       char euid_string[12];
    645       snprintf(euid_string, arraysize(euid_string), "%d", geteuid());
    646       asl_set(asl_message.get(), ASL_KEY_READ_UID, euid_string);
    647 
    648       // Map Chrome log severities to ASL log levels.
    649       const char* const asl_level_string = [](LogSeverity severity) {
    650         // ASL_LEVEL_* are ints, but ASL needs equivalent strings. This
    651         // non-obvious two-step macro trick achieves what's needed.
    652         // https://gcc.gnu.org/onlinedocs/cpp/Stringification.html
    653 #define ASL_LEVEL_STR(level) ASL_LEVEL_STR_X(level)
    654 #define ASL_LEVEL_STR_X(level) #level
    655         switch (severity) {
    656           case LOG_INFO:
    657             return ASL_LEVEL_STR(ASL_LEVEL_INFO);
    658           case LOG_WARNING:
    659             return ASL_LEVEL_STR(ASL_LEVEL_WARNING);
    660           case LOG_ERROR:
    661             return ASL_LEVEL_STR(ASL_LEVEL_ERR);
    662           case LOG_FATAL:
    663             return ASL_LEVEL_STR(ASL_LEVEL_CRIT);
    664           default:
    665             return severity < 0 ? ASL_LEVEL_STR(ASL_LEVEL_DEBUG)
    666                                 : ASL_LEVEL_STR(ASL_LEVEL_NOTICE);
    667         }
    668 #undef ASL_LEVEL_STR
    669 #undef ASL_LEVEL_STR_X
    670       }(severity_);
    671       asl_set(asl_message.get(), ASL_KEY_LEVEL, asl_level_string);
    672 
    673       asl_set(asl_message.get(), ASL_KEY_MSG, str_newline.c_str());
    674 
    675       asl_send(asl_client.get(), asl_message.get());
    676     }
    677 #elif defined(OS_ANDROID) || defined(__ANDROID__)
    678     android_LogPriority priority =
    679         (severity_ < 0) ? ANDROID_LOG_VERBOSE : ANDROID_LOG_UNKNOWN;
    680     switch (severity_) {
    681       case LOG_INFO:
    682         priority = ANDROID_LOG_INFO;
    683         break;
    684       case LOG_WARNING:
    685         priority = ANDROID_LOG_WARN;
    686         break;
    687       case LOG_ERROR:
    688         priority = ANDROID_LOG_ERROR;
    689         break;
    690       case LOG_FATAL:
    691         priority = ANDROID_LOG_FATAL;
    692         break;
    693     }
    694 #if defined(OS_ANDROID)
    695     __android_log_write(priority, "chromium", str_newline.c_str());
    696 #else
    697     __android_log_write(
    698         priority,
    699         base::CommandLine::InitializedForCurrentProcess() ?
    700             base::CommandLine::ForCurrentProcess()->
    701                 GetProgram().BaseName().value().c_str() : nullptr,
    702         str_newline.c_str());
    703 #endif  // defined(OS_ANDROID)
    704 #endif
    705     ignore_result(fwrite(str_newline.data(), str_newline.size(), 1, stderr));
    706     fflush(stderr);
    707   } else if (severity_ >= kAlwaysPrintErrorLevel) {
    708     // When we're only outputting to a log file, above a certain log level, we
    709     // should still output to stderr so that we can better detect and diagnose
    710     // problems with unit tests, especially on the buildbots.
    711     ignore_result(fwrite(str_newline.data(), str_newline.size(), 1, stderr));
    712     fflush(stderr);
    713   }
    714 
    715   // write to log file
    716   if ((g_logging_destination & LOG_TO_FILE) != 0) {
    717     // We can have multiple threads and/or processes, so try to prevent them
    718     // from clobbering each other's writes.
    719     // If the client app did not call InitLogging, and the lock has not
    720     // been created do it now. We do this on demand, but if two threads try
    721     // to do this at the same time, there will be a race condition to create
    722     // the lock. This is why InitLogging should be called from the main
    723     // thread at the beginning of execution.
    724 #if !defined(OS_WIN)
    725     LoggingLock::Init(LOCK_LOG_FILE, nullptr);
    726     LoggingLock logging_lock;
    727 #endif
    728     if (InitializeLogFileHandle()) {
    729 #if defined(OS_WIN)
    730       DWORD num_written;
    731       WriteFile(g_log_file,
    732                 static_cast<const void*>(str_newline.c_str()),
    733                 static_cast<DWORD>(str_newline.length()),
    734                 &num_written,
    735                 nullptr);
    736 #else
    737       ignore_result(fwrite(
    738           str_newline.data(), str_newline.size(), 1, g_log_file));
    739       fflush(g_log_file);
    740 #endif
    741     }
    742   }
    743 
    744   if (severity_ == LOG_FATAL) {
    745     // Write the log message to the global activity tracker, if running.
    746     base::debug::GlobalActivityTracker* tracker =
    747         base::debug::GlobalActivityTracker::Get();
    748     if (tracker)
    749       tracker->RecordLogMessage(str_newline);
    750 
    751     // Ensure the first characters of the string are on the stack so they
    752     // are contained in minidumps for diagnostic purposes.
    753     char str_stack[1024];
    754     str_newline.copy(str_stack, arraysize(str_stack));
    755     base::debug::Alias(str_stack);
    756 
    757     if (log_assert_handler) {
    758       // Make a copy of the string for the handler out of paranoia.
    759       log_assert_handler(std::string(stream_.str()));
    760     } else {
    761       // Don't use the string with the newline, get a fresh version to send to
    762       // the debug message process. We also don't display assertions to the
    763       // user in release mode. The enduser can't do anything with this
    764       // information, and displaying message boxes when the application is
    765       // hosed can cause additional problems.
    766 #ifndef NDEBUG
    767       if (!base::debug::BeingDebugged()) {
    768         // Displaying a dialog is unnecessary when debugging and can complicate
    769         // debugging.
    770         DisplayDebugMessageInDialog(stream_.str());
    771       }
    772 #endif
    773       // Crash the process to generate a dump.
    774       base::debug::BreakDebugger();
    775     }
    776   }
    777 }
    778 
    779 // writes the common header info to the stream
    780 void LogMessage::Init(const char* file, int line) {
    781   base::StringPiece filename(file);
    782   size_t last_slash_pos = filename.find_last_of("\\/");
    783   if (last_slash_pos != base::StringPiece::npos)
    784     filename.remove_prefix(last_slash_pos + 1);
    785 
    786   // TODO(darin): It might be nice if the columns were fixed width.
    787 
    788   stream_ <<  '[';
    789   if (g_log_process_id)
    790     stream_ << CurrentProcessId() << ':';
    791   if (g_log_thread_id)
    792     stream_ << base::PlatformThread::CurrentId() << ':';
    793   if (g_log_timestamp) {
    794 #if defined(OS_POSIX)
    795     timeval tv;
    796     gettimeofday(&tv, nullptr);
    797     time_t t = tv.tv_sec;
    798     struct tm local_time;
    799     localtime_r(&t, &local_time);
    800     struct tm* tm_time = &local_time;
    801     stream_ << std::setfill('0')
    802             << std::setw(2) << 1 + tm_time->tm_mon
    803             << std::setw(2) << tm_time->tm_mday
    804             << '/'
    805             << std::setw(2) << tm_time->tm_hour
    806             << std::setw(2) << tm_time->tm_min
    807             << std::setw(2) << tm_time->tm_sec
    808             << '.'
    809             << std::setw(6) << tv.tv_usec
    810             << ':';
    811 #elif defined(OS_WIN)
    812     SYSTEMTIME local_time;
    813     GetLocalTime(&local_time);
    814     stream_ << std::setfill('0')
    815             << std::setw(2) << local_time.wMonth
    816             << std::setw(2) << local_time.wDay
    817             << '/'
    818             << std::setw(2) << local_time.wHour
    819             << std::setw(2) << local_time.wMinute
    820             << std::setw(2) << local_time.wSecond
    821             << '.'
    822             << std::setw(3) << local_time.wMilliseconds
    823             << ':';
    824 #endif
    825   }
    826   if (g_log_tickcount)
    827     stream_ << TickCount() << ':';
    828   if (severity_ >= 0)
    829     stream_ << log_severity_name(severity_);
    830   else
    831     stream_ << "VERBOSE" << -severity_;
    832 
    833   stream_ << ":" << filename << "(" << line << ")] ";
    834 
    835   message_start_ = stream_.str().length();
    836 }
    837 
    838 #if defined(OS_WIN)
    839 // This has already been defined in the header, but defining it again as DWORD
    840 // ensures that the type used in the header is equivalent to DWORD. If not,
    841 // the redefinition is a compile error.
    842 typedef DWORD SystemErrorCode;
    843 #endif
    844 
    845 SystemErrorCode GetLastSystemErrorCode() {
    846 #if defined(OS_WIN)
    847   return ::GetLastError();
    848 #elif defined(OS_POSIX)
    849   return errno;
    850 #else
    851 #error Not implemented
    852 #endif
    853 }
    854 
    855 #if defined(OS_WIN)
    856 BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code) {
    857   const int kErrorMessageBufferSize = 256;
    858   char msgbuf[kErrorMessageBufferSize];
    859   DWORD flags = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
    860   DWORD len = FormatMessageA(flags, nullptr, error_code, 0, msgbuf,
    861                              arraysize(msgbuf), nullptr);
    862   if (len) {
    863     // Messages returned by system end with line breaks.
    864     return base::CollapseWhitespaceASCII(msgbuf, true) +
    865         base::StringPrintf(" (0x%X)", error_code);
    866   }
    867   return base::StringPrintf("Error (0x%X) while retrieving error. (0x%X)",
    868                             GetLastError(), error_code);
    869 }
    870 #elif defined(OS_POSIX)
    871 BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code) {
    872   return base::safe_strerror(error_code);
    873 }
    874 #else
    875 #error Not implemented
    876 #endif  // defined(OS_WIN)
    877 
    878 
    879 #if defined(OS_WIN)
    880 Win32ErrorLogMessage::Win32ErrorLogMessage(const char* file,
    881                                            int line,
    882                                            LogSeverity severity,
    883                                            SystemErrorCode err)
    884     : err_(err),
    885       log_message_(file, line, severity) {
    886 }
    887 
    888 Win32ErrorLogMessage::~Win32ErrorLogMessage() {
    889   stream() << ": " << SystemErrorCodeToString(err_);
    890   // We're about to crash (CHECK). Put |err_| on the stack (by placing it in a
    891   // field) and use Alias in hopes that it makes it into crash dumps.
    892   DWORD last_error = err_;
    893   base::debug::Alias(&last_error);
    894 }
    895 #elif defined(OS_POSIX)
    896 ErrnoLogMessage::ErrnoLogMessage(const char* file,
    897                                  int line,
    898                                  LogSeverity severity,
    899                                  SystemErrorCode err)
    900     : err_(err),
    901       log_message_(file, line, severity) {
    902 }
    903 
    904 ErrnoLogMessage::~ErrnoLogMessage() {
    905   stream() << ": " << SystemErrorCodeToString(err_);
    906 }
    907 #endif  // defined(OS_WIN)
    908 
    909 void CloseLogFile() {
    910 #if !defined(OS_WIN)
    911   LoggingLock logging_lock;
    912 #endif
    913   CloseLogFileUnlocked();
    914 }
    915 
    916 void RawLog(int level, const char* message) {
    917   if (level >= g_min_log_level && message) {
    918     size_t bytes_written = 0;
    919     const size_t message_len = strlen(message);
    920     int rv;
    921     while (bytes_written < message_len) {
    922       rv = HANDLE_EINTR(
    923           write(STDERR_FILENO, message + bytes_written,
    924                 message_len - bytes_written));
    925       if (rv < 0) {
    926         // Give up, nothing we can do now.
    927         break;
    928       }
    929       bytes_written += rv;
    930     }
    931 
    932     if (message_len > 0 && message[message_len - 1] != '\n') {
    933       do {
    934         rv = HANDLE_EINTR(write(STDERR_FILENO, "\n", 1));
    935         if (rv < 0) {
    936           // Give up, nothing we can do now.
    937           break;
    938         }
    939       } while (rv != 1);
    940     }
    941   }
    942 
    943   if (level == LOG_FATAL)
    944     base::debug::BreakDebugger();
    945 }
    946 
    947 // This was defined at the beginning of this file.
    948 #undef write
    949 
    950 #if defined(OS_WIN)
    951 bool IsLoggingToFileEnabled() {
    952   return g_logging_destination & LOG_TO_FILE;
    953 }
    954 
    955 std::wstring GetLogFileFullPath() {
    956   if (g_log_file_name)
    957     return *g_log_file_name;
    958   return std::wstring();
    959 }
    960 #endif
    961 
    962 BASE_EXPORT void LogErrorNotReached(const char* file, int line) {
    963   LogMessage(file, line, LOG_ERROR).stream()
    964       << "NOTREACHED() hit.";
    965 }
    966 
    967 }  // namespace logging
    968 
    969 std::ostream& std::operator<<(std::ostream& out, const wchar_t* wstr) {
    970   return out << (wstr ? base::WideToUTF8(wstr) : std::string());
    971 }
    972