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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/macros.h"
     11 #include "build/build_config.h"
     12 
     13 #if defined(OS_WIN)
     14 #include <io.h>
     15 #include <windows.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 LoggingSettings::LoggingSettings()
    350     : logging_dest(LOG_DEFAULT),
    351       log_file(nullptr),
    352       lock_log(LOCK_LOG_FILE),
    353       delete_old(APPEND_TO_OLD_LOG_FILE) {}
    354 
    355 bool BaseInitLoggingImpl(const LoggingSettings& settings) {
    356 #if defined(OS_NACL)
    357   // Can log only to the system debug log.
    358   CHECK_EQ(settings.logging_dest & ~LOG_TO_SYSTEM_DEBUG_LOG, 0);
    359 #endif
    360   if (base::CommandLine::InitializedForCurrentProcess()) {
    361     base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
    362     // Don't bother initializing |g_vlog_info| unless we use one of the
    363     // vlog switches.
    364     if (command_line->HasSwitch(switches::kV) ||
    365         command_line->HasSwitch(switches::kVModule)) {
    366       // NOTE: If |g_vlog_info| has already been initialized, it might be in use
    367       // by another thread. Don't delete the old VLogInfo, just create a second
    368       // one. We keep track of both to avoid memory leak warnings.
    369       CHECK(!g_vlog_info_prev);
    370       g_vlog_info_prev = g_vlog_info;
    371 
    372       g_vlog_info =
    373           new VlogInfo(command_line->GetSwitchValueASCII(switches::kV),
    374                        command_line->GetSwitchValueASCII(switches::kVModule),
    375                        &g_min_log_level);
    376     }
    377   }
    378 
    379   g_logging_destination = settings.logging_dest;
    380 
    381   // ignore file options unless logging to file is set.
    382   if ((g_logging_destination & LOG_TO_FILE) == 0)
    383     return true;
    384 
    385 #if !defined(OS_WIN)
    386   LoggingLock::Init(settings.lock_log, settings.log_file);
    387   LoggingLock logging_lock;
    388 #endif
    389 
    390   // Calling InitLogging twice or after some log call has already opened the
    391   // default log file will re-initialize to the new options.
    392   CloseLogFileUnlocked();
    393 
    394   if (!g_log_file_name)
    395     g_log_file_name = new PathString();
    396   *g_log_file_name = settings.log_file;
    397   if (settings.delete_old == DELETE_OLD_LOG_FILE)
    398     DeleteFilePath(*g_log_file_name);
    399 
    400   return InitializeLogFileHandle();
    401 }
    402 
    403 void SetMinLogLevel(int level) {
    404   g_min_log_level = std::min(LOG_FATAL, level);
    405 }
    406 
    407 int GetMinLogLevel() {
    408   return g_min_log_level;
    409 }
    410 
    411 bool ShouldCreateLogMessage(int severity) {
    412   if (severity < g_min_log_level)
    413     return false;
    414 
    415   // Return true here unless we know ~LogMessage won't do anything. Note that
    416   // ~LogMessage writes to stderr if severity_ >= kAlwaysPrintErrorLevel, even
    417   // when g_logging_destination is LOG_NONE.
    418   return g_logging_destination != LOG_NONE || log_message_handler ||
    419          severity >= kAlwaysPrintErrorLevel;
    420 }
    421 
    422 int GetVlogVerbosity() {
    423   return std::max(-1, LOG_INFO - GetMinLogLevel());
    424 }
    425 
    426 int GetVlogLevelHelper(const char* file, size_t N) {
    427   DCHECK_GT(N, 0U);
    428   // Note: |g_vlog_info| may change on a different thread during startup
    429   // (but will always be valid or nullptr).
    430   VlogInfo* vlog_info = g_vlog_info;
    431   return vlog_info ?
    432       vlog_info->GetVlogLevel(base::StringPiece(file, N - 1)) :
    433       GetVlogVerbosity();
    434 }
    435 
    436 void SetLogItems(bool enable_process_id, bool enable_thread_id,
    437                  bool enable_timestamp, bool enable_tickcount) {
    438   g_log_process_id = enable_process_id;
    439   g_log_thread_id = enable_thread_id;
    440   g_log_timestamp = enable_timestamp;
    441   g_log_tickcount = enable_tickcount;
    442 }
    443 
    444 void SetShowErrorDialogs(bool enable_dialogs) {
    445   show_error_dialogs = enable_dialogs;
    446 }
    447 
    448 void SetLogAssertHandler(LogAssertHandlerFunction handler) {
    449   log_assert_handler = handler;
    450 }
    451 
    452 void SetLogMessageHandler(LogMessageHandlerFunction handler) {
    453   log_message_handler = handler;
    454 }
    455 
    456 LogMessageHandlerFunction GetLogMessageHandler() {
    457   return log_message_handler;
    458 }
    459 
    460 // Explicit instantiations for commonly used comparisons.
    461 template std::string* MakeCheckOpString<int, int>(
    462     const int&, const int&, const char* names);
    463 template std::string* MakeCheckOpString<unsigned long, unsigned long>(
    464     const unsigned long&, const unsigned long&, const char* names);
    465 template std::string* MakeCheckOpString<unsigned long, unsigned int>(
    466     const unsigned long&, const unsigned int&, const char* names);
    467 template std::string* MakeCheckOpString<unsigned int, unsigned long>(
    468     const unsigned int&, const unsigned long&, const char* names);
    469 template std::string* MakeCheckOpString<std::string, std::string>(
    470     const std::string&, const std::string&, const char* name);
    471 
    472 void MakeCheckOpValueString(std::ostream* os, std::nullptr_t) {
    473   (*os) << "nullptr";
    474 }
    475 
    476 #if !defined(NDEBUG)
    477 // Displays a message box to the user with the error message in it.
    478 // Used for fatal messages, where we close the app simultaneously.
    479 // This is for developers only; we don't use this in circumstances
    480 // (like release builds) where users could see it, since users don't
    481 // understand these messages anyway.
    482 void DisplayDebugMessageInDialog(const std::string& str) {
    483   if (str.empty())
    484     return;
    485 
    486   if (!show_error_dialogs)
    487     return;
    488 
    489 #if defined(OS_WIN)
    490   MessageBoxW(nullptr, base::UTF8ToUTF16(str).c_str(), L"Fatal error",
    491               MB_OK | MB_ICONHAND | MB_TOPMOST);
    492 #else
    493   // We intentionally don't implement a dialog on other platforms.
    494   // You can just look at stderr.
    495 #endif  // defined(OS_WIN)
    496 }
    497 #endif  // !defined(NDEBUG)
    498 
    499 #if defined(OS_WIN)
    500 LogMessage::SaveLastError::SaveLastError() : last_error_(::GetLastError()) {
    501 }
    502 
    503 LogMessage::SaveLastError::~SaveLastError() {
    504   ::SetLastError(last_error_);
    505 }
    506 #endif  // defined(OS_WIN)
    507 
    508 LogMessage::LogMessage(const char* file, int line, LogSeverity severity)
    509     : severity_(severity), file_(file), line_(line) {
    510   Init(file, line);
    511 }
    512 
    513 LogMessage::LogMessage(const char* file, int line, const char* condition)
    514     : severity_(LOG_FATAL), file_(file), line_(line) {
    515   Init(file, line);
    516   stream_ << "Check failed: " << condition << ". ";
    517 }
    518 
    519 LogMessage::LogMessage(const char* file, int line, std::string* result)
    520     : severity_(LOG_FATAL), file_(file), line_(line) {
    521   Init(file, line);
    522   stream_ << "Check failed: " << *result;
    523   delete result;
    524 }
    525 
    526 LogMessage::LogMessage(const char* file, int line, LogSeverity severity,
    527                        std::string* result)
    528     : severity_(severity), file_(file), line_(line) {
    529   Init(file, line);
    530   stream_ << "Check failed: " << *result;
    531   delete result;
    532 }
    533 
    534 LogMessage::~LogMessage() {
    535 #if !defined(OFFICIAL_BUILD) && !defined(OS_NACL) && !defined(__UCLIBC__)
    536   if (severity_ == LOG_FATAL && !base::debug::BeingDebugged()) {
    537     // Include a stack trace on a fatal, unless a debugger is attached.
    538     base::debug::StackTrace trace;
    539     stream_ << std::endl;  // Newline to separate from log message.
    540     trace.OutputToStream(&stream_);
    541   }
    542 #endif
    543   stream_ << std::endl;
    544   std::string str_newline(stream_.str());
    545 
    546   // Give any log message handler first dibs on the message.
    547   if (log_message_handler &&
    548       log_message_handler(severity_, file_, line_,
    549                           message_start_, str_newline)) {
    550     // The handler took care of it, no further processing.
    551     return;
    552   }
    553 
    554   if ((g_logging_destination & LOG_TO_SYSTEM_DEBUG_LOG) != 0) {
    555 #if defined(OS_WIN)
    556     OutputDebugStringA(str_newline.c_str());
    557 #elif defined(OS_MACOSX)
    558     // In LOG_TO_SYSTEM_DEBUG_LOG mode, log messages are always written to
    559     // stderr. If stderr is /dev/null, also log via ASL (Apple System Log). If
    560     // there's something weird about stderr, assume that log messages are going
    561     // nowhere and log via ASL too. Messages logged via ASL show up in
    562     // Console.app.
    563     //
    564     // Programs started by launchd, as UI applications normally are, have had
    565     // stderr connected to /dev/null since OS X 10.8. Prior to that, stderr was
    566     // a pipe to launchd, which logged what it received (see log_redirect_fd in
    567     // 10.7.5 launchd-392.39/launchd/src/launchd_core_logic.c).
    568     //
    569     // Another alternative would be to determine whether stderr is a pipe to
    570     // launchd and avoid logging via ASL only in that case. See 10.7.5
    571     // CF-635.21/CFUtilities.c also_do_stderr(). This would result in logging to
    572     // both stderr and ASL even in tests, where it's undesirable to log to the
    573     // system log at all.
    574     //
    575     // Note that the ASL client by default discards messages whose levels are
    576     // below ASL_LEVEL_NOTICE. It's possible to change that with
    577     // asl_set_filter(), but this is pointless because syslogd normally applies
    578     // the same filter.
    579     const bool log_via_asl = []() {
    580       struct stat stderr_stat;
    581       if (fstat(fileno(stderr), &stderr_stat) == -1) {
    582         return true;
    583       }
    584       if (!S_ISCHR(stderr_stat.st_mode)) {
    585         return false;
    586       }
    587 
    588       struct stat dev_null_stat;
    589       if (stat(_PATH_DEVNULL, &dev_null_stat) == -1) {
    590         return true;
    591       }
    592 
    593       return !S_ISCHR(dev_null_stat.st_mode) ||
    594              stderr_stat.st_rdev == dev_null_stat.st_rdev;
    595     }();
    596 
    597     if (log_via_asl) {
    598       // Log roughly the same way that CFLog() and NSLog() would. See 10.10.5
    599       // CF-1153.18/CFUtilities.c __CFLogCString().
    600       //
    601       // The ASL facility is set to the main bundle ID if available. Otherwise,
    602       // "com.apple.console" is used.
    603       CFBundleRef main_bundle = CFBundleGetMainBundle();
    604       CFStringRef main_bundle_id_cf =
    605           main_bundle ? CFBundleGetIdentifier(main_bundle) : nullptr;
    606       std::string asl_facility =
    607           main_bundle_id_cf ? base::SysCFStringRefToUTF8(main_bundle_id_cf)
    608                             : std::string("com.apple.console");
    609 
    610       class ASLClient {
    611        public:
    612         explicit ASLClient(const std::string& asl_facility)
    613             : client_(asl_open(nullptr,
    614                                asl_facility.c_str(),
    615                                ASL_OPT_NO_DELAY)) {}
    616         ~ASLClient() { asl_close(client_); }
    617 
    618         aslclient get() const { return client_; }
    619 
    620        private:
    621         aslclient client_;
    622         DISALLOW_COPY_AND_ASSIGN(ASLClient);
    623       } asl_client(asl_facility);
    624 
    625       class ASLMessage {
    626        public:
    627         ASLMessage() : message_(asl_new(ASL_TYPE_MSG)) {}
    628         ~ASLMessage() { asl_free(message_); }
    629 
    630         aslmsg get() const { return message_; }
    631 
    632        private:
    633         aslmsg message_;
    634         DISALLOW_COPY_AND_ASSIGN(ASLMessage);
    635       } asl_message;
    636 
    637       // By default, messages are only readable by the admin group. Explicitly
    638       // make them readable by the user generating the messages.
    639       char euid_string[12];
    640       snprintf(euid_string, arraysize(euid_string), "%d", geteuid());
    641       asl_set(asl_message.get(), ASL_KEY_READ_UID, euid_string);
    642 
    643       // Map Chrome log severities to ASL log levels.
    644       const char* const asl_level_string = [](LogSeverity severity) {
    645         // ASL_LEVEL_* are ints, but ASL needs equivalent strings. This
    646         // non-obvious two-step macro trick achieves what's needed.
    647         // https://gcc.gnu.org/onlinedocs/cpp/Stringification.html
    648 #define ASL_LEVEL_STR(level) ASL_LEVEL_STR_X(level)
    649 #define ASL_LEVEL_STR_X(level) #level
    650         switch (severity) {
    651           case LOG_INFO:
    652             return ASL_LEVEL_STR(ASL_LEVEL_INFO);
    653           case LOG_WARNING:
    654             return ASL_LEVEL_STR(ASL_LEVEL_WARNING);
    655           case LOG_ERROR:
    656             return ASL_LEVEL_STR(ASL_LEVEL_ERR);
    657           case LOG_FATAL:
    658             return ASL_LEVEL_STR(ASL_LEVEL_CRIT);
    659           default:
    660             return severity < 0 ? ASL_LEVEL_STR(ASL_LEVEL_DEBUG)
    661                                 : ASL_LEVEL_STR(ASL_LEVEL_NOTICE);
    662         }
    663 #undef ASL_LEVEL_STR
    664 #undef ASL_LEVEL_STR_X
    665       }(severity_);
    666       asl_set(asl_message.get(), ASL_KEY_LEVEL, asl_level_string);
    667 
    668       asl_set(asl_message.get(), ASL_KEY_MSG, str_newline.c_str());
    669 
    670       asl_send(asl_client.get(), asl_message.get());
    671     }
    672 #elif defined(OS_ANDROID) || defined(__ANDROID__)
    673     android_LogPriority priority =
    674         (severity_ < 0) ? ANDROID_LOG_VERBOSE : ANDROID_LOG_UNKNOWN;
    675     switch (severity_) {
    676       case LOG_INFO:
    677         priority = ANDROID_LOG_INFO;
    678         break;
    679       case LOG_WARNING:
    680         priority = ANDROID_LOG_WARN;
    681         break;
    682       case LOG_ERROR:
    683         priority = ANDROID_LOG_ERROR;
    684         break;
    685       case LOG_FATAL:
    686         priority = ANDROID_LOG_FATAL;
    687         break;
    688     }
    689 #if defined(OS_ANDROID)
    690     __android_log_write(priority, "chromium", str_newline.c_str());
    691 #else
    692     __android_log_write(
    693         priority,
    694         base::CommandLine::InitializedForCurrentProcess() ?
    695             base::CommandLine::ForCurrentProcess()->
    696                 GetProgram().BaseName().value().c_str() : nullptr,
    697         str_newline.c_str());
    698 #endif  // defined(OS_ANDROID)
    699 #endif
    700     ignore_result(fwrite(str_newline.data(), str_newline.size(), 1, stderr));
    701     fflush(stderr);
    702   } else if (severity_ >= kAlwaysPrintErrorLevel) {
    703     // When we're only outputting to a log file, above a certain log level, we
    704     // should still output to stderr so that we can better detect and diagnose
    705     // problems with unit tests, especially on the buildbots.
    706     ignore_result(fwrite(str_newline.data(), str_newline.size(), 1, stderr));
    707     fflush(stderr);
    708   }
    709 
    710   // write to log file
    711   if ((g_logging_destination & LOG_TO_FILE) != 0) {
    712     // We can have multiple threads and/or processes, so try to prevent them
    713     // from clobbering each other's writes.
    714     // If the client app did not call InitLogging, and the lock has not
    715     // been created do it now. We do this on demand, but if two threads try
    716     // to do this at the same time, there will be a race condition to create
    717     // the lock. This is why InitLogging should be called from the main
    718     // thread at the beginning of execution.
    719 #if !defined(OS_WIN)
    720     LoggingLock::Init(LOCK_LOG_FILE, nullptr);
    721     LoggingLock logging_lock;
    722 #endif
    723     if (InitializeLogFileHandle()) {
    724 #if defined(OS_WIN)
    725       DWORD num_written;
    726       WriteFile(g_log_file,
    727                 static_cast<const void*>(str_newline.c_str()),
    728                 static_cast<DWORD>(str_newline.length()),
    729                 &num_written,
    730                 nullptr);
    731 #else
    732       ignore_result(fwrite(
    733           str_newline.data(), str_newline.size(), 1, g_log_file));
    734       fflush(g_log_file);
    735 #endif
    736     }
    737   }
    738 
    739   if (severity_ == LOG_FATAL) {
    740     // Ensure the first characters of the string are on the stack so they
    741     // are contained in minidumps for diagnostic purposes.
    742     char str_stack[1024];
    743     str_newline.copy(str_stack, arraysize(str_stack));
    744     base::debug::Alias(str_stack);
    745 
    746     if (log_assert_handler) {
    747       // Make a copy of the string for the handler out of paranoia.
    748       log_assert_handler(std::string(stream_.str()));
    749     } else {
    750       // Don't use the string with the newline, get a fresh version to send to
    751       // the debug message process. We also don't display assertions to the
    752       // user in release mode. The enduser can't do anything with this
    753       // information, and displaying message boxes when the application is
    754       // hosed can cause additional problems.
    755 #ifndef NDEBUG
    756       if (!base::debug::BeingDebugged()) {
    757         // Displaying a dialog is unnecessary when debugging and can complicate
    758         // debugging.
    759         DisplayDebugMessageInDialog(stream_.str());
    760       }
    761 #endif
    762       // Crash the process to generate a dump.
    763       base::debug::BreakDebugger();
    764     }
    765   }
    766 }
    767 
    768 // writes the common header info to the stream
    769 void LogMessage::Init(const char* file, int line) {
    770   base::StringPiece filename(file);
    771   size_t last_slash_pos = filename.find_last_of("\\/");
    772   if (last_slash_pos != base::StringPiece::npos)
    773     filename.remove_prefix(last_slash_pos + 1);
    774 
    775   // TODO(darin): It might be nice if the columns were fixed width.
    776 
    777   stream_ <<  '[';
    778   if (g_log_process_id)
    779     stream_ << CurrentProcessId() << ':';
    780   if (g_log_thread_id)
    781     stream_ << base::PlatformThread::CurrentId() << ':';
    782   if (g_log_timestamp) {
    783     time_t t = time(nullptr);
    784 #if defined(__ANDROID__) || defined(ANDROID)
    785     struct tm local_time;
    786     memset(&local_time, 0, sizeof(local_time));
    787 #else
    788     struct tm local_time = {0};
    789 #endif
    790 #ifdef _MSC_VER
    791     localtime_s(&local_time, &t);
    792 #else
    793     localtime_r(&t, &local_time);
    794 #endif
    795     struct tm* tm_time = &local_time;
    796     stream_ << std::setfill('0')
    797             << std::setw(2) << 1 + tm_time->tm_mon
    798             << std::setw(2) << tm_time->tm_mday
    799             << '/'
    800             << std::setw(2) << tm_time->tm_hour
    801             << std::setw(2) << tm_time->tm_min
    802             << std::setw(2) << tm_time->tm_sec
    803             << ':';
    804   }
    805   if (g_log_tickcount)
    806     stream_ << TickCount() << ':';
    807   if (severity_ >= 0)
    808     stream_ << log_severity_name(severity_);
    809   else
    810     stream_ << "VERBOSE" << -severity_;
    811 
    812   stream_ << ":" << filename << "(" << line << ")] ";
    813 
    814   message_start_ = stream_.str().length();
    815 }
    816 
    817 #if defined(OS_WIN)
    818 // This has already been defined in the header, but defining it again as DWORD
    819 // ensures that the type used in the header is equivalent to DWORD. If not,
    820 // the redefinition is a compile error.
    821 typedef DWORD SystemErrorCode;
    822 #endif
    823 
    824 SystemErrorCode GetLastSystemErrorCode() {
    825 #if defined(OS_WIN)
    826   return ::GetLastError();
    827 #elif defined(OS_POSIX)
    828   return errno;
    829 #else
    830 #error Not implemented
    831 #endif
    832 }
    833 
    834 #if defined(OS_WIN)
    835 BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code) {
    836   const int kErrorMessageBufferSize = 256;
    837   char msgbuf[kErrorMessageBufferSize];
    838   DWORD flags = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
    839   DWORD len = FormatMessageA(flags, nullptr, error_code, 0, msgbuf,
    840                              arraysize(msgbuf), nullptr);
    841   if (len) {
    842     // Messages returned by system end with line breaks.
    843     return base::CollapseWhitespaceASCII(msgbuf, true) +
    844         base::StringPrintf(" (0x%X)", error_code);
    845   }
    846   return base::StringPrintf("Error (0x%X) while retrieving error. (0x%X)",
    847                             GetLastError(), error_code);
    848 }
    849 #elif defined(OS_POSIX)
    850 BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code) {
    851   return base::safe_strerror(error_code);
    852 }
    853 #else
    854 #error Not implemented
    855 #endif  // defined(OS_WIN)
    856 
    857 
    858 #if defined(OS_WIN)
    859 Win32ErrorLogMessage::Win32ErrorLogMessage(const char* file,
    860                                            int line,
    861                                            LogSeverity severity,
    862                                            SystemErrorCode err)
    863     : err_(err),
    864       log_message_(file, line, severity) {
    865 }
    866 
    867 Win32ErrorLogMessage::~Win32ErrorLogMessage() {
    868   stream() << ": " << SystemErrorCodeToString(err_);
    869   // We're about to crash (CHECK). Put |err_| on the stack (by placing it in a
    870   // field) and use Alias in hopes that it makes it into crash dumps.
    871   DWORD last_error = err_;
    872   base::debug::Alias(&last_error);
    873 }
    874 #elif defined(OS_POSIX)
    875 ErrnoLogMessage::ErrnoLogMessage(const char* file,
    876                                  int line,
    877                                  LogSeverity severity,
    878                                  SystemErrorCode err)
    879     : err_(err),
    880       log_message_(file, line, severity) {
    881 }
    882 
    883 ErrnoLogMessage::~ErrnoLogMessage() {
    884   stream() << ": " << SystemErrorCodeToString(err_);
    885 }
    886 #endif  // defined(OS_WIN)
    887 
    888 void CloseLogFile() {
    889 #if !defined(OS_WIN)
    890   LoggingLock logging_lock;
    891 #endif
    892   CloseLogFileUnlocked();
    893 }
    894 
    895 void RawLog(int level, const char* message) {
    896   if (level >= g_min_log_level && message) {
    897     size_t bytes_written = 0;
    898     const size_t message_len = strlen(message);
    899     int rv;
    900     while (bytes_written < message_len) {
    901       rv = HANDLE_EINTR(
    902           write(STDERR_FILENO, message + bytes_written,
    903                 message_len - bytes_written));
    904       if (rv < 0) {
    905         // Give up, nothing we can do now.
    906         break;
    907       }
    908       bytes_written += rv;
    909     }
    910 
    911     if (message_len > 0 && message[message_len - 1] != '\n') {
    912       do {
    913         rv = HANDLE_EINTR(write(STDERR_FILENO, "\n", 1));
    914         if (rv < 0) {
    915           // Give up, nothing we can do now.
    916           break;
    917         }
    918       } while (rv != 1);
    919     }
    920   }
    921 
    922   if (level == LOG_FATAL)
    923     base::debug::BreakDebugger();
    924 }
    925 
    926 // This was defined at the beginning of this file.
    927 #undef write
    928 
    929 #if defined(OS_WIN)
    930 bool IsLoggingToFileEnabled() {
    931   return g_logging_destination & LOG_TO_FILE;
    932 }
    933 
    934 std::wstring GetLogFileFullPath() {
    935   if (g_log_file_name)
    936     return *g_log_file_name;
    937   return std::wstring();
    938 }
    939 #endif
    940 
    941 BASE_EXPORT void LogErrorNotReached(const char* file, int line) {
    942   LogMessage(file, line, LOG_ERROR).stream()
    943       << "NOTREACHED() hit.";
    944 }
    945 
    946 }  // namespace logging
    947 
    948 std::ostream& std::operator<<(std::ostream& out, const wchar_t* wstr) {
    949   return out << (wstr ? base::WideToUTF8(wstr) : std::string());
    950 }
    951