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      1 // Copyright (c) 2011 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 #if defined(OS_WIN)
      8 #include <io.h>
      9 #include <windows.h>
     10 typedef HANDLE FileHandle;
     11 typedef HANDLE MutexHandle;
     12 // Windows warns on using write().  It prefers _write().
     13 #define write(fd, buf, count) _write(fd, buf, static_cast<unsigned int>(count))
     14 // Windows doesn't define STDERR_FILENO.  Define it here.
     15 #define STDERR_FILENO 2
     16 #elif defined(OS_MACOSX)
     17 #include <mach/mach.h>
     18 #include <mach/mach_time.h>
     19 #include <mach-o/dyld.h>
     20 #elif defined(OS_POSIX)
     21 #if defined(OS_NACL)
     22 #include <sys/nacl_syscalls.h>
     23 #include <sys/time.h> // timespec doesn't seem to be in <time.h>
     24 #else
     25 #include <sys/syscall.h>
     26 #endif
     27 #include <time.h>
     28 #endif
     29 
     30 #if defined(OS_POSIX)
     31 #include <errno.h>
     32 #include <pthread.h>
     33 #include <stdlib.h>
     34 #include <stdio.h>
     35 #include <string.h>
     36 #include <unistd.h>
     37 #define MAX_PATH PATH_MAX
     38 typedef FILE* FileHandle;
     39 typedef pthread_mutex_t* MutexHandle;
     40 #endif
     41 
     42 #include <algorithm>
     43 #include <cstring>
     44 #include <ctime>
     45 #include <iomanip>
     46 #include <ostream>
     47 
     48 #include "base/base_switches.h"
     49 #include "base/command_line.h"
     50 #include "base/debug/debugger.h"
     51 #include "base/debug/stack_trace.h"
     52 #include "base/eintr_wrapper.h"
     53 #include "base/string_piece.h"
     54 #include "base/synchronization/lock_impl.h"
     55 #include "base/utf_string_conversions.h"
     56 #include "base/vlog.h"
     57 #if defined(OS_POSIX)
     58 #include "base/safe_strerror_posix.h"
     59 #endif
     60 
     61 namespace logging {
     62 
     63 #ifdef ANDROID
     64 BASE_API
     65 #endif
     66 DcheckState g_dcheck_state = DISABLE_DCHECK_FOR_NON_OFFICIAL_RELEASE_BUILDS;
     67 VlogInfo* g_vlog_info = NULL;
     68 
     69 const char* const log_severity_names[LOG_NUM_SEVERITIES] = {
     70   "INFO", "WARNING", "ERROR", "ERROR_REPORT", "FATAL" };
     71 
     72 int min_log_level = 0;
     73 
     74 // The default set here for logging_destination will only be used if
     75 // InitLogging is not called.  On Windows, use a file next to the exe;
     76 // on POSIX platforms, where it may not even be possible to locate the
     77 // executable on disk, use stderr.
     78 #if defined(OS_WIN)
     79 LoggingDestination logging_destination = LOG_ONLY_TO_FILE;
     80 #elif defined(OS_POSIX)
     81 LoggingDestination logging_destination = LOG_ONLY_TO_SYSTEM_DEBUG_LOG;
     82 #endif
     83 
     84 // For LOG_ERROR and above, always print to stderr.
     85 const int kAlwaysPrintErrorLevel = LOG_ERROR;
     86 
     87 // Which log file to use? This is initialized by InitLogging or
     88 // will be lazily initialized to the default value when it is
     89 // first needed.
     90 #if defined(OS_WIN)
     91 typedef std::wstring PathString;
     92 #else
     93 typedef std::string PathString;
     94 #endif
     95 PathString* log_file_name = NULL;
     96 
     97 // this file is lazily opened and the handle may be NULL
     98 FileHandle log_file = NULL;
     99 
    100 // what should be prepended to each message?
    101 bool log_process_id = false;
    102 bool log_thread_id = false;
    103 bool log_timestamp = true;
    104 bool log_tickcount = false;
    105 
    106 // Should we pop up fatal debug messages in a dialog?
    107 bool show_error_dialogs = false;
    108 
    109 // An assert handler override specified by the client to be called instead of
    110 // the debug message dialog and process termination.
    111 LogAssertHandlerFunction log_assert_handler = NULL;
    112 // An report handler override specified by the client to be called instead of
    113 // the debug message dialog.
    114 LogReportHandlerFunction log_report_handler = NULL;
    115 // A log message handler that gets notified of every log message we process.
    116 LogMessageHandlerFunction log_message_handler = NULL;
    117 
    118 // Helper functions to wrap platform differences.
    119 
    120 int32 CurrentProcessId() {
    121 #if defined(OS_WIN)
    122   return GetCurrentProcessId();
    123 #elif defined(OS_POSIX)
    124   return getpid();
    125 #endif
    126 }
    127 
    128 int32 CurrentThreadId() {
    129 #if defined(OS_WIN)
    130   return GetCurrentThreadId();
    131 #elif defined(OS_MACOSX)
    132   return mach_thread_self();
    133 #elif defined(OS_LINUX)
    134   return syscall(__NR_gettid);
    135 #elif defined(OS_FREEBSD)
    136   // TODO(BSD): find a better thread ID
    137   return reinterpret_cast<int64>(pthread_self());
    138 #elif defined(OS_NACL)
    139   return pthread_self();
    140 #endif
    141 }
    142 
    143 uint64 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 absolute_micro =
    157     static_cast<int64>(ts.tv_sec) * 1000000 +
    158     static_cast<int64>(ts.tv_nsec) / 1000;
    159 
    160   return absolute_micro;
    161 #endif
    162 }
    163 
    164 void CloseFile(FileHandle log) {
    165 #if defined(OS_WIN)
    166   CloseHandle(log);
    167 #else
    168   fclose(log);
    169 #endif
    170 }
    171 
    172 void DeleteFilePath(const PathString& log_name) {
    173 #if defined(OS_WIN)
    174   DeleteFile(log_name.c_str());
    175 #else
    176   unlink(log_name.c_str());
    177 #endif
    178 }
    179 
    180 PathString GetDefaultLogFile() {
    181 #if defined(OS_WIN)
    182   // On Windows we use the same path as the exe.
    183   wchar_t module_name[MAX_PATH];
    184   GetModuleFileName(NULL, module_name, MAX_PATH);
    185 
    186   PathString log_file = module_name;
    187   PathString::size_type last_backslash =
    188       log_file.rfind('\\', log_file.size());
    189   if (last_backslash != PathString::npos)
    190     log_file.erase(last_backslash + 1);
    191   log_file += L"debug.log";
    192   return log_file;
    193 #elif defined(OS_POSIX)
    194   // On other platforms we just use the current directory.
    195   return PathString("debug.log");
    196 #endif
    197 }
    198 
    199 // This class acts as a wrapper for locking the logging files.
    200 // LoggingLock::Init() should be called from the main thread before any logging
    201 // is done. Then whenever logging, be sure to have a local LoggingLock
    202 // instance on the stack. This will ensure that the lock is unlocked upon
    203 // exiting the frame.
    204 // LoggingLocks can not be nested.
    205 class LoggingLock {
    206  public:
    207   LoggingLock() {
    208     LockLogging();
    209   }
    210 
    211   ~LoggingLock() {
    212     UnlockLogging();
    213   }
    214 
    215   static void Init(LogLockingState lock_log, const PathChar* new_log_file) {
    216     if (initialized)
    217       return;
    218     lock_log_file = lock_log;
    219     if (lock_log_file == LOCK_LOG_FILE) {
    220 #if defined(OS_WIN)
    221       if (!log_mutex) {
    222         std::wstring safe_name;
    223         if (new_log_file)
    224           safe_name = new_log_file;
    225         else
    226           safe_name = GetDefaultLogFile();
    227         // \ is not a legal character in mutex names so we replace \ with /
    228         std::replace(safe_name.begin(), safe_name.end(), '\\', '/');
    229         std::wstring t(L"Global\\");
    230         t.append(safe_name);
    231         log_mutex = ::CreateMutex(NULL, FALSE, t.c_str());
    232 
    233         if (log_mutex == NULL) {
    234 #if DEBUG
    235           // Keep the error code for debugging
    236           int error = GetLastError();  // NOLINT
    237           base::debug::BreakDebugger();
    238 #endif
    239           // Return nicely without putting initialized to true.
    240           return;
    241         }
    242       }
    243 #endif
    244     } else {
    245       log_lock = new base::internal::LockImpl();
    246     }
    247     initialized = true;
    248   }
    249 
    250  private:
    251   static void LockLogging() {
    252     if (lock_log_file == LOCK_LOG_FILE) {
    253 #if defined(OS_WIN)
    254       ::WaitForSingleObject(log_mutex, INFINITE);
    255       // WaitForSingleObject could have returned WAIT_ABANDONED. We don't
    256       // abort the process here. UI tests might be crashy sometimes,
    257       // and aborting the test binary only makes the problem worse.
    258       // We also don't use LOG macros because that might lead to an infinite
    259       // loop. For more info see http://crbug.com/18028.
    260 #elif defined(OS_POSIX)
    261       pthread_mutex_lock(&log_mutex);
    262 #endif
    263     } else {
    264       // use the lock
    265       log_lock->Lock();
    266     }
    267   }
    268 
    269   static void UnlockLogging() {
    270     if (lock_log_file == LOCK_LOG_FILE) {
    271 #if defined(OS_WIN)
    272       ReleaseMutex(log_mutex);
    273 #elif defined(OS_POSIX)
    274       pthread_mutex_unlock(&log_mutex);
    275 #endif
    276     } else {
    277       log_lock->Unlock();
    278     }
    279   }
    280 
    281   // The lock is used if log file locking is false. It helps us avoid problems
    282   // with multiple threads writing to the log file at the same time.  Use
    283   // LockImpl directly instead of using Lock, because Lock makes logging calls.
    284   static base::internal::LockImpl* log_lock;
    285 
    286   // When we don't use a lock, we are using a global mutex. We need to do this
    287   // because LockFileEx is not thread safe.
    288 #if defined(OS_WIN)
    289   static MutexHandle log_mutex;
    290 #elif defined(OS_POSIX)
    291   static pthread_mutex_t log_mutex;
    292 #endif
    293 
    294   static bool initialized;
    295   static LogLockingState lock_log_file;
    296 };
    297 
    298 // static
    299 bool LoggingLock::initialized = false;
    300 // static
    301 base::internal::LockImpl* LoggingLock::log_lock = NULL;
    302 // static
    303 LogLockingState LoggingLock::lock_log_file = LOCK_LOG_FILE;
    304 
    305 #if defined(OS_WIN)
    306 // static
    307 MutexHandle LoggingLock::log_mutex = NULL;
    308 #elif defined(OS_POSIX)
    309 pthread_mutex_t LoggingLock::log_mutex = PTHREAD_MUTEX_INITIALIZER;
    310 #endif
    311 
    312 // Called by logging functions to ensure that debug_file is initialized
    313 // and can be used for writing. Returns false if the file could not be
    314 // initialized. debug_file will be NULL in this case.
    315 bool InitializeLogFileHandle() {
    316   if (log_file)
    317     return true;
    318 
    319   if (!log_file_name) {
    320     // Nobody has called InitLogging to specify a debug log file, so here we
    321     // initialize the log file name to a default.
    322     log_file_name = new PathString(GetDefaultLogFile());
    323   }
    324 
    325   if (logging_destination == LOG_ONLY_TO_FILE ||
    326       logging_destination == LOG_TO_BOTH_FILE_AND_SYSTEM_DEBUG_LOG) {
    327 #if defined(OS_WIN)
    328     log_file = CreateFile(log_file_name->c_str(), GENERIC_WRITE,
    329                           FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
    330                           OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
    331     if (log_file == INVALID_HANDLE_VALUE || log_file == NULL) {
    332       // try the current directory
    333       log_file = CreateFile(L".\\debug.log", GENERIC_WRITE,
    334                             FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
    335                             OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
    336       if (log_file == INVALID_HANDLE_VALUE || log_file == NULL) {
    337         log_file = NULL;
    338         return false;
    339       }
    340     }
    341     SetFilePointer(log_file, 0, 0, FILE_END);
    342 #elif defined(OS_POSIX)
    343     log_file = fopen(log_file_name->c_str(), "a");
    344     if (log_file == NULL)
    345       return false;
    346 #endif
    347   }
    348 
    349   return true;
    350 }
    351 
    352 bool BaseInitLoggingImpl(const PathChar* new_log_file,
    353                          LoggingDestination logging_dest,
    354                          LogLockingState lock_log,
    355                          OldFileDeletionState delete_old,
    356                          DcheckState dcheck_state) {
    357 #ifdef ANDROID
    358   // ifdef is here because we don't support parsing command line parameters
    359   g_dcheck_state = dcheck_state;
    360   g_vlog_info = NULL;
    361 #else
    362   CommandLine* command_line = CommandLine::ForCurrentProcess();
    363   g_dcheck_state = dcheck_state;
    364   delete g_vlog_info;
    365   g_vlog_info = NULL;
    366   // Don't bother initializing g_vlog_info unless we use one of the
    367   // vlog switches.
    368   if (command_line->HasSwitch(switches::kV) ||
    369       command_line->HasSwitch(switches::kVModule)) {
    370     g_vlog_info =
    371         new VlogInfo(command_line->GetSwitchValueASCII(switches::kV),
    372                      command_line->GetSwitchValueASCII(switches::kVModule),
    373                      &min_log_level);
    374   }
    375 #endif
    376 
    377   LoggingLock::Init(lock_log, new_log_file);
    378 
    379   LoggingLock logging_lock;
    380 
    381   if (log_file) {
    382     // calling InitLogging twice or after some log call has already opened the
    383     // default log file will re-initialize to the new options
    384     CloseFile(log_file);
    385     log_file = NULL;
    386   }
    387 
    388   logging_destination = logging_dest;
    389 
    390   // ignore file options if logging is disabled or only to system
    391   if (logging_destination == LOG_NONE ||
    392       logging_destination == LOG_ONLY_TO_SYSTEM_DEBUG_LOG)
    393     return true;
    394 
    395   if (!log_file_name)
    396     log_file_name = new PathString();
    397   *log_file_name = new_log_file;
    398   if (delete_old == DELETE_OLD_LOG_FILE)
    399     DeleteFilePath(*log_file_name);
    400 
    401   return InitializeLogFileHandle();
    402 }
    403 
    404 void SetMinLogLevel(int level) {
    405   min_log_level = std::min(LOG_ERROR_REPORT, level);
    406 }
    407 
    408 int GetMinLogLevel() {
    409   return min_log_level;
    410 }
    411 
    412 int GetVlogVerbosity() {
    413   return std::max(-1, LOG_INFO - GetMinLogLevel());
    414 }
    415 
    416 int GetVlogLevelHelper(const char* file, size_t N) {
    417   DCHECK_GT(N, 0U);
    418   return g_vlog_info ?
    419       g_vlog_info->GetVlogLevel(base::StringPiece(file, N - 1)) :
    420       GetVlogVerbosity();
    421 }
    422 
    423 void SetLogItems(bool enable_process_id, bool enable_thread_id,
    424                  bool enable_timestamp, bool enable_tickcount) {
    425   log_process_id = enable_process_id;
    426   log_thread_id = enable_thread_id;
    427   log_timestamp = enable_timestamp;
    428   log_tickcount = enable_tickcount;
    429 }
    430 
    431 void SetShowErrorDialogs(bool enable_dialogs) {
    432   show_error_dialogs = enable_dialogs;
    433 }
    434 
    435 void SetLogAssertHandler(LogAssertHandlerFunction handler) {
    436   log_assert_handler = handler;
    437 }
    438 
    439 void SetLogReportHandler(LogReportHandlerFunction handler) {
    440   log_report_handler = handler;
    441 }
    442 
    443 void SetLogMessageHandler(LogMessageHandlerFunction handler) {
    444   log_message_handler = handler;
    445 }
    446 
    447 LogMessageHandlerFunction GetLogMessageHandler() {
    448   return log_message_handler;
    449 }
    450 
    451 // MSVC doesn't like complex extern templates and DLLs.
    452 #if !defined(COMPILER_MSVC)
    453 // Explicit instantiations for commonly used comparisons.
    454 template std::string* MakeCheckOpString<int, int>(
    455     const int&, const int&, const char* names);
    456 template std::string* MakeCheckOpString<unsigned long, unsigned long>(
    457     const unsigned long&, const unsigned long&, const char* names);
    458 template std::string* MakeCheckOpString<unsigned long, unsigned int>(
    459     const unsigned long&, const unsigned int&, const char* names);
    460 template std::string* MakeCheckOpString<unsigned int, unsigned long>(
    461     const unsigned int&, const unsigned long&, const char* names);
    462 template std::string* MakeCheckOpString<std::string, std::string>(
    463     const std::string&, const std::string&, const char* name);
    464 #endif
    465 
    466 // Displays a message box to the user with the error message in it.
    467 // Used for fatal messages, where we close the app simultaneously.
    468 // This is for developers only; we don't use this in circumstances
    469 // (like release builds) where users could see it, since users don't
    470 // understand these messages anyway.
    471 void DisplayDebugMessageInDialog(const std::string& str) {
    472   if (str.empty())
    473     return;
    474 
    475   if (!show_error_dialogs)
    476     return;
    477 
    478 #if defined(OS_WIN)
    479   // For Windows programs, it's possible that the message loop is
    480   // messed up on a fatal error, and creating a MessageBox will cause
    481   // that message loop to be run. Instead, we try to spawn another
    482   // process that displays its command line. We look for "Debug
    483   // Message.exe" in the same directory as the application. If it
    484   // exists, we use it, otherwise, we use a regular message box.
    485   wchar_t prog_name[MAX_PATH];
    486   GetModuleFileNameW(NULL, prog_name, MAX_PATH);
    487   wchar_t* backslash = wcsrchr(prog_name, '\\');
    488   if (backslash)
    489     backslash[1] = 0;
    490   wcscat_s(prog_name, MAX_PATH, L"debug_message.exe");
    491 
    492   std::wstring cmdline = UTF8ToWide(str);
    493   if (cmdline.empty())
    494     return;
    495 
    496   STARTUPINFO startup_info;
    497   memset(&startup_info, 0, sizeof(startup_info));
    498   startup_info.cb = sizeof(startup_info);
    499 
    500   PROCESS_INFORMATION process_info;
    501   if (CreateProcessW(prog_name, &cmdline[0], NULL, NULL, false, 0, NULL,
    502                      NULL, &startup_info, &process_info)) {
    503     WaitForSingleObject(process_info.hProcess, INFINITE);
    504     CloseHandle(process_info.hThread);
    505     CloseHandle(process_info.hProcess);
    506   } else {
    507     // debug process broken, let's just do a message box
    508     MessageBoxW(NULL, &cmdline[0], L"Fatal error",
    509                 MB_OK | MB_ICONHAND | MB_TOPMOST);
    510   }
    511 #else
    512   // We intentionally don't implement a dialog on other platforms.
    513   // You can just look at stderr.
    514 #endif
    515 }
    516 
    517 #if defined(OS_WIN)
    518 LogMessage::SaveLastError::SaveLastError() : last_error_(::GetLastError()) {
    519 }
    520 
    521 LogMessage::SaveLastError::~SaveLastError() {
    522   ::SetLastError(last_error_);
    523 }
    524 #endif  // defined(OS_WIN)
    525 
    526 LogMessage::LogMessage(const char* file, int line, LogSeverity severity,
    527                        int ctr)
    528     : severity_(severity), file_(file), line_(line) {
    529   Init(file, line);
    530 }
    531 
    532 LogMessage::LogMessage(const char* file, int line)
    533     : severity_(LOG_INFO), file_(file), line_(line) {
    534   Init(file, line);
    535 }
    536 
    537 LogMessage::LogMessage(const char* file, int line, LogSeverity severity)
    538     : severity_(severity), file_(file), line_(line) {
    539   Init(file, line);
    540 }
    541 
    542 LogMessage::LogMessage(const char* file, int line, std::string* result)
    543     : severity_(LOG_FATAL), file_(file), line_(line) {
    544   Init(file, line);
    545   stream_ << "Check failed: " << *result;
    546   delete result;
    547 }
    548 
    549 LogMessage::LogMessage(const char* file, int line, LogSeverity severity,
    550                        std::string* result)
    551     : severity_(severity), file_(file), line_(line) {
    552   Init(file, line);
    553   stream_ << "Check failed: " << *result;
    554   delete result;
    555 }
    556 
    557 LogMessage::~LogMessage() {
    558 #ifndef NDEBUG
    559   if (severity_ == LOG_FATAL) {
    560     // Include a stack trace on a fatal.
    561     base::debug::StackTrace trace;
    562     stream_ << std::endl;  // Newline to separate from log message.
    563     trace.OutputToStream(&stream_);
    564   }
    565 #endif
    566   stream_ << std::endl;
    567   std::string str_newline(stream_.str());
    568 
    569   // Give any log message handler first dibs on the message.
    570   if (log_message_handler && log_message_handler(severity_, file_, line_,
    571           message_start_, str_newline)) {
    572     // The handler took care of it, no further processing.
    573     return;
    574   }
    575 
    576   if (logging_destination == LOG_ONLY_TO_SYSTEM_DEBUG_LOG ||
    577       logging_destination == LOG_TO_BOTH_FILE_AND_SYSTEM_DEBUG_LOG) {
    578 #if defined(OS_WIN)
    579     OutputDebugStringA(str_newline.c_str());
    580 #endif
    581     fprintf(stderr, "%s", str_newline.c_str());
    582     fflush(stderr);
    583   } else if (severity_ >= kAlwaysPrintErrorLevel) {
    584     // When we're only outputting to a log file, above a certain log level, we
    585     // should still output to stderr so that we can better detect and diagnose
    586     // problems with unit tests, especially on the buildbots.
    587     fprintf(stderr, "%s", str_newline.c_str());
    588     fflush(stderr);
    589   }
    590 
    591   // We can have multiple threads and/or processes, so try to prevent them
    592   // from clobbering each other's writes.
    593   // If the client app did not call InitLogging, and the lock has not
    594   // been created do it now. We do this on demand, but if two threads try
    595   // to do this at the same time, there will be a race condition to create
    596   // the lock. This is why InitLogging should be called from the main
    597   // thread at the beginning of execution.
    598   LoggingLock::Init(LOCK_LOG_FILE, NULL);
    599   // write to log file
    600   if (logging_destination != LOG_NONE &&
    601       logging_destination != LOG_ONLY_TO_SYSTEM_DEBUG_LOG) {
    602     LoggingLock logging_lock;
    603     if (InitializeLogFileHandle()) {
    604 #if defined(OS_WIN)
    605       SetFilePointer(log_file, 0, 0, SEEK_END);
    606       DWORD num_written;
    607       WriteFile(log_file,
    608                 static_cast<const void*>(str_newline.c_str()),
    609                 static_cast<DWORD>(str_newline.length()),
    610                 &num_written,
    611                 NULL);
    612 #else
    613       fprintf(log_file, "%s", str_newline.c_str());
    614       fflush(log_file);
    615 #endif
    616     }
    617   }
    618 
    619   if (severity_ == LOG_FATAL) {
    620     // display a message or break into the debugger on a fatal error
    621     if (base::debug::BeingDebugged()) {
    622       base::debug::BreakDebugger();
    623     } else {
    624       if (log_assert_handler) {
    625         // make a copy of the string for the handler out of paranoia
    626         log_assert_handler(std::string(stream_.str()));
    627       } else {
    628         // Don't use the string with the newline, get a fresh version to send to
    629         // the debug message process. We also don't display assertions to the
    630         // user in release mode. The enduser can't do anything with this
    631         // information, and displaying message boxes when the application is
    632         // hosed can cause additional problems.
    633 #ifndef NDEBUG
    634         DisplayDebugMessageInDialog(stream_.str());
    635 #endif
    636         // Crash the process to generate a dump.
    637         base::debug::BreakDebugger();
    638       }
    639     }
    640   } else if (severity_ == LOG_ERROR_REPORT) {
    641     // We are here only if the user runs with --enable-dcheck in release mode.
    642     if (log_report_handler) {
    643       log_report_handler(std::string(stream_.str()));
    644     } else {
    645       DisplayDebugMessageInDialog(stream_.str());
    646     }
    647   }
    648 }
    649 
    650 // writes the common header info to the stream
    651 void LogMessage::Init(const char* file, int line) {
    652   base::StringPiece filename(file);
    653   size_t last_slash_pos = filename.find_last_of("\\/");
    654   if (last_slash_pos != base::StringPiece::npos)
    655     filename.remove_prefix(last_slash_pos + 1);
    656 
    657   // TODO(darin): It might be nice if the columns were fixed width.
    658 
    659   stream_ <<  '[';
    660   if (log_process_id)
    661     stream_ << CurrentProcessId() << ':';
    662   if (log_thread_id)
    663     stream_ << CurrentThreadId() << ':';
    664   if (log_timestamp) {
    665     time_t t = time(NULL);
    666     struct tm local_time = {0};
    667 #if _MSC_VER >= 1400
    668     localtime_s(&local_time, &t);
    669 #else
    670     localtime_r(&t, &local_time);
    671 #endif
    672     struct tm* tm_time = &local_time;
    673     stream_ << std::setfill('0')
    674             << std::setw(2) << 1 + tm_time->tm_mon
    675             << std::setw(2) << tm_time->tm_mday
    676             << '/'
    677             << std::setw(2) << tm_time->tm_hour
    678             << std::setw(2) << tm_time->tm_min
    679             << std::setw(2) << tm_time->tm_sec
    680             << ':';
    681   }
    682   if (log_tickcount)
    683     stream_ << TickCount() << ':';
    684   if (severity_ >= 0)
    685     stream_ << log_severity_names[severity_];
    686   else
    687     stream_ << "VERBOSE" << -severity_;
    688 
    689   stream_ << ":" << filename << "(" << line << ")] ";
    690 
    691   message_start_ = stream_.tellp();
    692 }
    693 
    694 #if defined(OS_WIN)
    695 // This has already been defined in the header, but defining it again as DWORD
    696 // ensures that the type used in the header is equivalent to DWORD. If not,
    697 // the redefinition is a compile error.
    698 typedef DWORD SystemErrorCode;
    699 #endif
    700 
    701 SystemErrorCode GetLastSystemErrorCode() {
    702 #if defined(OS_WIN)
    703   return ::GetLastError();
    704 #elif defined(OS_POSIX)
    705   return errno;
    706 #else
    707 #error Not implemented
    708 #endif
    709 }
    710 
    711 #if defined(OS_WIN)
    712 Win32ErrorLogMessage::Win32ErrorLogMessage(const char* file,
    713                                            int line,
    714                                            LogSeverity severity,
    715                                            SystemErrorCode err,
    716                                            const char* module)
    717     : err_(err),
    718       module_(module),
    719       log_message_(file, line, severity) {
    720 }
    721 
    722 Win32ErrorLogMessage::Win32ErrorLogMessage(const char* file,
    723                                            int line,
    724                                            LogSeverity severity,
    725                                            SystemErrorCode err)
    726     : err_(err),
    727       module_(NULL),
    728       log_message_(file, line, severity) {
    729 }
    730 
    731 Win32ErrorLogMessage::~Win32ErrorLogMessage() {
    732   const int error_message_buffer_size = 256;
    733   char msgbuf[error_message_buffer_size];
    734   DWORD flags = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
    735   HMODULE hmod;
    736   if (module_) {
    737     hmod = GetModuleHandleA(module_);
    738     if (hmod) {
    739       flags |= FORMAT_MESSAGE_FROM_HMODULE;
    740     } else {
    741       // This makes a nested Win32ErrorLogMessage. It will have module_ of NULL
    742       // so it will not call GetModuleHandle, so recursive errors are
    743       // impossible.
    744       DPLOG(WARNING) << "Couldn't open module " << module_
    745           << " for error message query";
    746     }
    747   } else {
    748     hmod = NULL;
    749   }
    750   DWORD len = FormatMessageA(flags,
    751                              hmod,
    752                              err_,
    753                              0,
    754                              msgbuf,
    755                              sizeof(msgbuf) / sizeof(msgbuf[0]),
    756                              NULL);
    757   if (len) {
    758     while ((len > 0) &&
    759            isspace(static_cast<unsigned char>(msgbuf[len - 1]))) {
    760       msgbuf[--len] = 0;
    761     }
    762     stream() << ": " << msgbuf;
    763   } else {
    764     stream() << ": Error " << GetLastError() << " while retrieving error "
    765         << err_;
    766   }
    767 }
    768 #elif defined(OS_POSIX)
    769 ErrnoLogMessage::ErrnoLogMessage(const char* file,
    770                                  int line,
    771                                  LogSeverity severity,
    772                                  SystemErrorCode err)
    773     : err_(err),
    774       log_message_(file, line, severity) {
    775 }
    776 
    777 ErrnoLogMessage::~ErrnoLogMessage() {
    778   stream() << ": " << safe_strerror(err_);
    779 }
    780 #endif  // OS_WIN
    781 
    782 void CloseLogFile() {
    783   LoggingLock logging_lock;
    784 
    785   if (!log_file)
    786     return;
    787 
    788   CloseFile(log_file);
    789   log_file = NULL;
    790 }
    791 
    792 void RawLog(int level, const char* message) {
    793   if (level >= min_log_level) {
    794     size_t bytes_written = 0;
    795     const size_t message_len = strlen(message);
    796     int rv;
    797     while (bytes_written < message_len) {
    798       rv = HANDLE_EINTR(
    799           write(STDERR_FILENO, message + bytes_written,
    800                 message_len - bytes_written));
    801       if (rv < 0) {
    802         // Give up, nothing we can do now.
    803         break;
    804       }
    805       bytes_written += rv;
    806     }
    807 
    808     if (message_len > 0 && message[message_len - 1] != '\n') {
    809       do {
    810         rv = HANDLE_EINTR(write(STDERR_FILENO, "\n", 1));
    811         if (rv < 0) {
    812           // Give up, nothing we can do now.
    813           break;
    814         }
    815       } while (rv != 1);
    816     }
    817   }
    818 
    819   if (level == LOG_FATAL)
    820     base::debug::BreakDebugger();
    821 }
    822 
    823 }  // namespace logging
    824 
    825 std::ostream& operator<<(std::ostream& out, const wchar_t* wstr) {
    826   return out << WideToUTF8(std::wstring(wstr));
    827 }
    828 
    829 namespace base {
    830 
    831 // This was defined at the beginnig of this file.
    832 #undef write
    833 
    834 std::ostream& operator<<(std::ostream& o, const StringPiece& piece) {
    835   o.write(piece.data(), static_cast<std::streamsize>(piece.size()));
    836   return o;
    837 }
    838 
    839 }  // namespace base
    840