base/logging.cc

   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 #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/time.h>  // timespec doesn't seem to be in <time.h>
  23 #else
  24 #include <sys/syscall.h>
  25 #endif
  26 #include <time.h>
  27 #endif
  28
  29 #if defined(OS_POSIX)
  30 #include <errno.h>
  31 #include <pthread.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35 #include <unistd.h>
  36 #define MAX_PATH PATH_MAX
  37 typedef FILE* FileHandle;
  38 typedef pthread_mutex_t* MutexHandle;
  39 #endif
  40
  41 #include <algorithm>
  42 #include <cstring>
  43 #include <ctime>
  44 #include <iomanip>
  45 #include <ostream>
  46 #include <string>
  47
  48 #include "base/base_switches.h"
  49 #include "base/command_line.h"
  50 #include "base/debug/alias.h"
  51 #include "base/debug/debugger.h"
  52 #include "base/debug/stack_trace.h"
  53 #include "base/posix/eintr_wrapper.h"
  54 #include "base/strings/string_piece.h"
  55 #include "base/strings/string_util.h"
  56 #include "base/strings/stringprintf.h"
  57 #include "base/strings/utf_string_conversions.h"
  58 #include "base/synchronization/lock_impl.h"
  59 #include "base/threading/platform_thread.h"
  60 #include "base/vlog.h"
  61 #if defined(OS_POSIX)
  62 #include "base/safe_strerror_posix.h"
  63 #endif
  64
  65 #if defined(OS_ANDROID)
  66 #include <android/log.h>
  67 #endif
  68
  69 namespace logging {
  70
  71 namespace {
  72
  73 VlogInfo* g_vlog_info = NULL;
  74 VlogInfo* g_vlog_info_prev = NULL;
  75
  76 const char* const log_severity_names[LOG_NUM_SEVERITIES] = {
  77   "INFO", "WARNING", "ERROR", "FATAL" };
  78
  79 const char* log_severity_name(int severity) {
  80   if (severity >= 0 && severity < LOG_NUM_SEVERITIES)
  81     return log_severity_names[severity];
  82   return "UNKNOWN";
  83 }
  84
  85 int min_log_level = 0;
  86
  87 LoggingDestination logging_destination = LOG_DEFAULT;
  88
  89 // For LOG_ERROR and above, always print to stderr.
  90 const int kAlwaysPrintErrorLevel = LOG_ERROR;
  91
  92 // Which log file to use? This is initialized by InitLogging or
  93 // will be lazily initialized to the default value when it is
  94 // first needed.
  95 #if defined(OS_WIN)
  96 typedef std::wstring PathString;
  97 #else
  98 typedef std::string PathString;
  99 #endif
 100 PathString* log_file_name = NULL;
 101
 102 // this file is lazily opened and the handle may be NULL
 103 FileHandle log_file = NULL;
 104
 105 // what should be prepended to each message?
 106 bool log_process_id = false;
 107 bool log_thread_id = false;
 108 bool log_timestamp = true;
 109 bool log_tickcount = false;
 110
 111 // Should we pop up fatal debug messages in a dialog?
 112 bool show_error_dialogs = false;
 113
 114 // An assert handler override specified by the client to be called instead of
 115 // the debug message dialog and process termination.
 116 LogAssertHandlerFunction log_assert_handler = NULL;
 117 // A log message handler that gets notified of every log message we process.
 118 LogMessageHandlerFunction log_message_handler = NULL;
 119
 120 // Helper functions to wrap platform differences.
 121
 122 int32 CurrentProcessId() {
 123 #if defined(OS_WIN)
 124   return GetCurrentProcessId();
 125 #elif defined(OS_POSIX)
 126   return getpid();
 127 #endif
 128 }
 129
 130 uint64 TickCount() {
 131 #if defined(OS_WIN)
 132   return GetTickCount();
 133 #elif defined(OS_MACOSX)
 134   return mach_absolute_time();
 135 #elif defined(OS_NACL)
 136   // NaCl sadly does not have _POSIX_TIMERS enabled in sys/features.h
 137   // So we have to use clock() for now.
 138   return clock();
 139 #elif defined(OS_POSIX)
 140   struct timespec ts;
 141   clock_gettime(CLOCK_MONOTONIC, &ts);
 142
 143   uint64 absolute_micro =
 144     static_cast<int64>(ts.tv_sec) * 1000000 +
 145     static_cast<int64>(ts.tv_nsec) / 1000;
 146
 147   return absolute_micro;
 148 #endif
 149 }
 150
 151 void DeleteFilePath(const PathString& log_name) {
 152 #if defined(OS_WIN)
 153   DeleteFile(log_name.c_str());
 154 #elif defined(OS_NACL)
 155   // Do nothing; unlink() isn't supported on NaCl.
 156 #else
 157   unlink(log_name.c_str());
 158 #endif
 159 }
 160
 161 PathString GetDefaultLogFile() {
 162 #if defined(OS_WIN)
 163   // On Windows we use the same path as the exe.
 164   wchar_t module_name[MAX_PATH];
 165   GetModuleFileName(NULL, module_name, MAX_PATH);
 166
 167   PathString log_file = module_name;
 168   PathString::size_type last_backslash =
 169       log_file.rfind('\\', log_file.size());
 170   if (last_backslash != PathString::npos)
 171     log_file.erase(last_backslash + 1);
 172   log_file += L"debug.log";
 173   return log_file;
 174 #elif defined(OS_POSIX)
 175   // On other platforms we just use the current directory.
 176   return PathString("debug.log");
 177 #endif
 178 }
 179
 180 // This class acts as a wrapper for locking the logging files.
 181 // LoggingLock::Init() should be called from the main thread before any logging
 182 // is done. Then whenever logging, be sure to have a local LoggingLock
 183 // instance on the stack. This will ensure that the lock is unlocked upon
 184 // exiting the frame.
 185 // LoggingLocks can not be nested.
 186 class LoggingLock {
 187  public:
 188   LoggingLock() {
 189     LockLogging();
 190   }
 191
 192   ~LoggingLock() {
 193     UnlockLogging();
 194   }
 195
 196   static void Init(LogLockingState lock_log, const PathChar* new_log_file) {
 197     if (initialized)
 198       return;
 199     lock_log_file = lock_log;
 200     if (lock_log_file == LOCK_LOG_FILE) {
 201 #if defined(OS_WIN)
 202       if (!log_mutex) {
 203         std::wstring safe_name;
 204         if (new_log_file)
 205           safe_name = new_log_file;
 206         else
 207           safe_name = GetDefaultLogFile();
 208         // \ is not a legal character in mutex names so we replace \ with /
 209         std::replace(safe_name.begin(), safe_name.end(), '\\', '/');
 210         std::wstring t(L"Global\\");
 211         t.append(safe_name);
 212         log_mutex = ::CreateMutex(NULL, FALSE, t.c_str());
 213
 214         if (log_mutex == NULL) {
 215 #if DEBUG
 216           // Keep the error code for debugging
 217           int error = GetLastError();  // NOLINT
 218           base::debug::BreakDebugger();
 219 #endif
 220           // Return nicely without putting initialized to true.
 221           return;
 222         }
 223       }
 224 #endif
 225     } else {
 226       log_lock = new base::internal::LockImpl();
 227     }
 228     initialized = true;
 229   }
 230
 231  private:
 232   static void LockLogging() {
 233     if (lock_log_file == LOCK_LOG_FILE) {
 234 #if defined(OS_WIN)
 235       ::WaitForSingleObject(log_mutex, INFINITE);
 236       // WaitForSingleObject could have returned WAIT_ABANDONED. We don't
 237       // abort the process here. UI tests might be crashy sometimes,
 238       // and aborting the test binary only makes the problem worse.
 239       // We also don't use LOG macros because that might lead to an infinite
 240       // loop. For more info see http://crbug.com/18028.
 241 #elif defined(OS_POSIX)
 242       pthread_mutex_lock(&log_mutex);
 243 #endif
 244     } else {
 245       // use the lock
 246       log_lock->Lock();
 247     }
 248   }
 249
 250   static void UnlockLogging() {
 251     if (lock_log_file == LOCK_LOG_FILE) {
 252 #if defined(OS_WIN)
 253       ReleaseMutex(log_mutex);
 254 #elif defined(OS_POSIX)
 255       pthread_mutex_unlock(&log_mutex);
 256 #endif
 257     } else {
 258       log_lock->Unlock();
 259     }
 260   }
 261
 262   // The lock is used if log file locking is false. It helps us avoid problems
 263   // with multiple threads writing to the log file at the same time.  Use
 264   // LockImpl directly instead of using Lock, because Lock makes logging calls.
 265   static base::internal::LockImpl* log_lock;
 266
 267   // When we don't use a lock, we are using a global mutex. We need to do this
 268   // because LockFileEx is not thread safe.
 269 #if defined(OS_WIN)
 270   static MutexHandle log_mutex;
 271 #elif defined(OS_POSIX)
 272   static pthread_mutex_t log_mutex;
 273 #endif
 274
 275   static bool initialized;
 276   static LogLockingState lock_log_file;
 277 };
 278
 279 // static
 280 bool LoggingLock::initialized = false;
 281 // static
 282 base::internal::LockImpl* LoggingLock::log_lock = NULL;
 283 // static
 284 LogLockingState LoggingLock::lock_log_file = LOCK_LOG_FILE;
 285
 286 #if defined(OS_WIN)
 287 // static
 288 MutexHandle LoggingLock::log_mutex = NULL;
 289 #elif defined(OS_POSIX)
 290 pthread_mutex_t LoggingLock::log_mutex = PTHREAD_MUTEX_INITIALIZER;
 291 #endif
 292
 293 // Called by logging functions to ensure that debug_file is initialized
 294 // and can be used for writing. Returns false if the file could not be
 295 // initialized. debug_file will be NULL in this case.
 296 bool InitializeLogFileHandle() {
 297   if (log_file)
 298     return true;
 299
 300   if (!log_file_name) {
 301     // Nobody has called InitLogging to specify a debug log file, so here we
 302     // initialize the log file name to a default.
 303     log_file_name = new PathString(GetDefaultLogFile());
 304   }
 305
 306   if ((logging_destination & LOG_TO_FILE) != 0) {
 307 #if defined(OS_WIN)
 308     log_file = CreateFile(log_file_name->c_str(), GENERIC_WRITE,
 309                           FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
 310                           OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
 311     if (log_file == INVALID_HANDLE_VALUE || log_file == NULL) {
 312       // try the current directory
 313       log_file = CreateFile(L".\\debug.log", GENERIC_WRITE,
 314                             FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
 315                             OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
 316       if (log_file == INVALID_HANDLE_VALUE || log_file == NULL) {
 317         log_file = NULL;
 318         return false;
 319       }
 320     }
 321     SetFilePointer(log_file, 0, 0, FILE_END);
 322 #elif defined(OS_POSIX)
 323     log_file = fopen(log_file_name->c_str(), "a");
 324     if (log_file == NULL)
 325       return false;
 326 #endif
 327   }
 328
 329   return true;
 330 }
 331
 332 void CloseFile(FileHandle log) {
 333 #if defined(OS_WIN)
 334   CloseHandle(log);
 335 #else
 336   fclose(log);
 337 #endif
 338 }
 339
 340 void CloseLogFileUnlocked() {
 341   if (!log_file)
 342     return;
 343
 344   CloseFile(log_file);
 345   log_file = NULL;
 346 }
 347
 348 }  // namespace
 349
 350 LoggingSettings::LoggingSettings()
 351     : logging_dest(LOG_DEFAULT),
 352       log_file(NULL),
 353       lock_log(LOCK_LOG_FILE),
 354       delete_old(APPEND_TO_OLD_LOG_FILE) {}
 355
 356 bool BaseInitLoggingImpl(const LoggingSettings& settings) {
 357 #if defined(OS_NACL)
 358   // Can log only to the system debug log.
 359   CHECK_EQ(settings.logging_dest & ~LOG_TO_SYSTEM_DEBUG_LOG, 0);
 360 #endif
 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                      &min_log_level);
 376   }
 377
 378   logging_destination = settings.logging_dest;
 379
 380   // ignore file options unless logging to file is set.
 381   if ((logging_destination & LOG_TO_FILE) == 0)
 382     return true;
 383
 384   LoggingLock::Init(settings.lock_log, settings.log_file);
 385   LoggingLock logging_lock;
 386
 387   // Calling InitLogging twice or after some log call has already opened the
 388   // default log file will re-initialize to the new options.
 389   CloseLogFileUnlocked();
 390
 391   if (!log_file_name)
 392     log_file_name = new PathString();
 393   *log_file_name = settings.log_file;
 394   if (settings.delete_old == DELETE_OLD_LOG_FILE)
 395     DeleteFilePath(*log_file_name);
 396
 397   return InitializeLogFileHandle();
 398 }
 399
 400 void SetMinLogLevel(int level) {
 401   min_log_level = std::min(LOG_FATAL, level);
 402 }
 403
 404 int GetMinLogLevel() {
 405   return min_log_level;
 406 }
 407
 408 int GetVlogVerbosity() {
 409   return std::max(-1, LOG_INFO - GetMinLogLevel());
 410 }
 411
 412 int GetVlogLevelHelper(const char* file, size_t N) {
 413   DCHECK_GT(N, 0U);
 414   // Note: g_vlog_info may change on a different thread during startup
 415   // (but will always be valid or NULL).
 416   VlogInfo* vlog_info = g_vlog_info;
 417   return vlog_info ?
 418       vlog_info->GetVlogLevel(base::StringPiece(file, N - 1)) :
 419       GetVlogVerbosity();
 420 }
 421
 422 void SetLogItems(bool enable_process_id, bool enable_thread_id,
 423                  bool enable_timestamp, bool enable_tickcount) {
 424   log_process_id = enable_process_id;
 425   log_thread_id = enable_thread_id;
 426   log_timestamp = enable_timestamp;
 427   log_tickcount = enable_tickcount;
 428 }
 429
 430 void SetShowErrorDialogs(bool enable_dialogs) {
 431   show_error_dialogs = enable_dialogs;
 432 }
 433
 434 void SetLogAssertHandler(LogAssertHandlerFunction handler) {
 435   log_assert_handler = handler;
 436 }
 437
 438 void SetLogMessageHandler(LogMessageHandlerFunction handler) {
 439   log_message_handler = handler;
 440 }
 441
 442 LogMessageHandlerFunction GetLogMessageHandler() {
 443   return log_message_handler;
 444 }
 445
 446 // Explicit instantiations for commonly used comparisons.
 447 template std::string* MakeCheckOpString<int, int>(
 448     const int&, const int&, const char* names);
 449 template std::string* MakeCheckOpString<unsigned long, unsigned long>(
 450     const unsigned long&, const unsigned long&, const char* names);
 451 template std::string* MakeCheckOpString<unsigned long, unsigned int>(
 452     const unsigned long&, const unsigned int&, const char* names);
 453 template std::string* MakeCheckOpString<unsigned int, unsigned long>(
 454     const unsigned int&, const unsigned long&, const char* names);
 455 template std::string* MakeCheckOpString<std::string, std::string>(
 456     const std::string&, const std::string&, const char* name);
 457
 458 #if !defined(NDEBUG)
 459 // Displays a message box to the user with the error message in it.
 460 // Used for fatal messages, where we close the app simultaneously.
 461 // This is for developers only; we don't use this in circumstances
 462 // (like release builds) where users could see it, since users don't
 463 // understand these messages anyway.
 464 void DisplayDebugMessageInDialog(const std::string& str) {
 465   if (str.empty())
 466     return;
 467
 468   if (!show_error_dialogs)
 469     return;
 470
 471 #if defined(OS_WIN)
 472   // For Windows programs, it's possible that the message loop is
 473   // messed up on a fatal error, and creating a MessageBox will cause
 474   // that message loop to be run. Instead, we try to spawn another
 475   // process that displays its command line. We look for "Debug
 476   // Message.exe" in the same directory as the application. If it
 477   // exists, we use it, otherwise, we use a regular message box.
 478   wchar_t prog_name[MAX_PATH];
 479   GetModuleFileNameW(NULL, prog_name, MAX_PATH);
 480   wchar_t* backslash = wcsrchr(prog_name, '\\');
 481   if (backslash)
 482     backslash[1] = 0;
 483   wcscat_s(prog_name, MAX_PATH, L"debug_message.exe");
 484
 485   std::wstring cmdline = base::UTF8ToWide(str);
 486   if (cmdline.empty())
 487     return;
 488
 489   STARTUPINFO startup_info;
 490   memset(&startup_info, 0, sizeof(startup_info));
 491   startup_info.cb = sizeof(startup_info);
 492
 493   PROCESS_INFORMATION process_info;
 494   if (CreateProcessW(prog_name, &cmdline[0], NULL, NULL, false, 0, NULL,
 495                      NULL, &startup_info, &process_info)) {
 496     WaitForSingleObject(process_info.hProcess, INFINITE);
 497     CloseHandle(process_info.hThread);
 498     CloseHandle(process_info.hProcess);
 499   } else {
 500     // debug process broken, let's just do a message box
 501     MessageBoxW(NULL, &cmdline[0], L"Fatal error",
 502                 MB_OK | MB_ICONHAND | MB_TOPMOST);
 503   }
 504 #else
 505   // We intentionally don't implement a dialog on other platforms.
 506   // You can just look at stderr.
 507 #endif
 508 }
 509 #endif  // !defined(NDEBUG)
 510
 511 #if defined(OS_WIN)
 512 LogMessage::SaveLastError::SaveLastError() : last_error_(::GetLastError()) {
 513 }
 514
 515 LogMessage::SaveLastError::~SaveLastError() {
 516   ::SetLastError(last_error_);
 517 }
 518 #endif  // defined(OS_WIN)
 519
 520 LogMessage::LogMessage(const char* file, int line, LogSeverity severity)
 521     : severity_(severity), file_(file), line_(line) {
 522   Init(file, line);
 523 }
 524
 525 LogMessage::LogMessage(const char* file, int line, std::string* result)
 526     : severity_(LOG_FATAL), file_(file), line_(line) {
 527   Init(file, line);
 528   stream_ << "Check failed: " << *result;
 529   delete result;
 530 }
 531
 532 LogMessage::LogMessage(const char* file, int line, LogSeverity severity,
 533                        std::string* result)
 534     : severity_(severity), file_(file), line_(line) {
 535   Init(file, line);
 536   stream_ << "Check failed: " << *result;
 537   delete result;
 538 }
 539
 540 LogMessage::~LogMessage() {
 541 #if !defined(NDEBUG) && !defined(OS_NACL) && !defined(__UCLIBC__)
 542   if (severity_ == LOG_FATAL) {
 543     // Include a stack trace on a fatal.
 544     base::debug::StackTrace trace;
 545     stream_ << std::endl;  // Newline to separate from log message.
 546     trace.OutputToStream(&stream_);
 547   }
 548 #endif
 549   stream_ << std::endl;
 550   std::string str_newline(stream_.str());
 551
 552   // Give any log message handler first dibs on the message.
 553   if (log_message_handler &&
 554       log_message_handler(severity_, file_, line_,
 555                           message_start_, str_newline)) {
 556     // The handler took care of it, no further processing.
 557     return;
 558   }
 559
 560   if ((logging_destination & LOG_TO_SYSTEM_DEBUG_LOG) != 0) {
 561 #if defined(OS_WIN)
 562     OutputDebugStringA(str_newline.c_str());
 563 #elif defined(OS_ANDROID)
 564     android_LogPriority priority =
 565         (severity_ < 0) ? ANDROID_LOG_VERBOSE : ANDROID_LOG_UNKNOWN;
 566     switch (severity_) {
 567       case LOG_INFO:
 568         priority = ANDROID_LOG_INFO;
 569         break;
 570       case LOG_WARNING:
 571         priority = ANDROID_LOG_WARN;
 572         break;
 573       case LOG_ERROR:
 574         priority = ANDROID_LOG_ERROR;
 575         break;
 576       case LOG_FATAL:
 577         priority = ANDROID_LOG_FATAL;
 578         break;
 579     }
 580     __android_log_write(priority, "chromium", str_newline.c_str());
 581 #endif
 582     ignore_result(fwrite(str_newline.data(), str_newline.size(), 1, stderr));
 583     fflush(stderr);
 584   } else if (severity_ >= kAlwaysPrintErrorLevel) {
 585     // When we're only outputting to a log file, above a certain log level, we
 586     // should still output to stderr so that we can better detect and diagnose
 587     // problems with unit tests, especially on the buildbots.
 588     ignore_result(fwrite(str_newline.data(), str_newline.size(), 1, stderr));
 589     fflush(stderr);
 590   }
 591
 592   // write to log file
 593   if ((logging_destination & LOG_TO_FILE) != 0) {
 594     // We can have multiple threads and/or processes, so try to prevent them
 595     // from clobbering each other's writes.
 596     // If the client app did not call InitLogging, and the lock has not
 597     // been created do it now. We do this on demand, but if two threads try
 598     // to do this at the same time, there will be a race condition to create
 599     // the lock. This is why InitLogging should be called from the main
 600     // thread at the beginning of execution.
 601     LoggingLock::Init(LOCK_LOG_FILE, NULL);
 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       ignore_result(fwrite(
 614           str_newline.data(), str_newline.size(), 1, log_file));
 615       fflush(log_file);
 616 #endif
 617     }
 618   }
 619
 620   if (severity_ == LOG_FATAL) {
 621     // Ensure the first characters of the string are on the stack so they
 622     // are contained in minidumps for diagnostic purposes.
 623     char str_stack[1024];
 624     str_newline.copy(str_stack, arraysize(str_stack));
 625     base::debug::Alias(str_stack);
 626
 627     if (log_assert_handler) {
 628       // Make a copy of the string for the handler out of paranoia.
 629       log_assert_handler(std::string(stream_.str()));
 630     } else {
 631       // Don't use the string with the newline, get a fresh version to send to
 632       // the debug message process. We also don't display assertions to the
 633       // user in release mode. The enduser can't do anything with this
 634       // information, and displaying message boxes when the application is
 635       // hosed can cause additional problems.
 636 #ifndef NDEBUG
 637       DisplayDebugMessageInDialog(stream_.str());
 638 #endif
 639       // Crash the process to generate a dump.
 640       base::debug::BreakDebugger();
 641     }
 642   }
 643 }
 644
 645 // writes the common header info to the stream
 646 void LogMessage::Init(const char* file, int line) {
 647   base::StringPiece filename(file);
 648   size_t last_slash_pos = filename.find_last_of("\\/");
 649   if (last_slash_pos != base::StringPiece::npos)
 650     filename.remove_prefix(last_slash_pos + 1);
 651
 652   // TODO(darin): It might be nice if the columns were fixed width.
 653
 654   stream_ <<  '[';
 655   if (log_process_id)
 656     stream_ << CurrentProcessId() << ':';
 657   if (log_thread_id)
 658     stream_ << base::PlatformThread::CurrentId() << ':';
 659   if (log_timestamp) {
 660     time_t t = time(NULL);
 661     struct tm local_time = {0};
 662 #ifdef _MSC_VER
 663     localtime_s(&local_time, &t);
 664 #else
 665     localtime_r(&t, &local_time);
 666 #endif
 667     struct tm* tm_time = &local_time;
 668     stream_ << std::setfill('0')
 669             << std::setw(2) << 1 + tm_time->tm_mon
 670             << std::setw(2) << tm_time->tm_mday
 671             << '/'
 672             << std::setw(2) << tm_time->tm_hour
 673             << std::setw(2) << tm_time->tm_min
 674             << std::setw(2) << tm_time->tm_sec
 675             << ':';
 676   }
 677   if (log_tickcount)
 678     stream_ << TickCount() << ':';
 679   if (severity_ >= 0)
 680     stream_ << log_severity_name(severity_);
 681   else
 682     stream_ << "VERBOSE" << -severity_;
 683
 684   stream_ << ":" << filename << "(" << line << ")] ";
 685
 686   message_start_ = stream_.str().length();
 687 }
 688
 689 #if defined(OS_WIN)
 690 // This has already been defined in the header, but defining it again as DWORD
 691 // ensures that the type used in the header is equivalent to DWORD. If not,
 692 // the redefinition is a compile error.
 693 typedef DWORD SystemErrorCode;
 694 #endif
 695
 696 SystemErrorCode GetLastSystemErrorCode() {
 697 #if defined(OS_WIN)
 698   return ::GetLastError();
 699 #elif defined(OS_POSIX)
 700   return errno;
 701 #else
 702 #error Not implemented
 703 #endif
 704 }
 705
 706 #if defined(OS_WIN)
 707 BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code) {
 708   const int kErrorMessageBufferSize = 256;
 709   char msgbuf[kErrorMessageBufferSize];
 710   DWORD flags = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
 711   DWORD len = FormatMessageA(flags, NULL, error_code, 0, msgbuf,
 712                              arraysize(msgbuf), NULL);
 713   if (len) {
 714     // Messages returned by system end with line breaks.
 715     return base::CollapseWhitespaceASCII(msgbuf, true) +
 716         base::StringPrintf(" (0x%X)", error_code);
 717   }
 718   return base::StringPrintf("Error (0x%X) while retrieving error. (0x%X)",
 719                             GetLastError(), error_code);
 720 }
 721 #elif defined(OS_POSIX)
 722 BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code) {
 723   return safe_strerror(error_code);
 724 }
 725 #else
 726 #error Not implemented
 727 #endif
 728
 729
 730 #if defined(OS_WIN)
 731 Win32ErrorLogMessage::Win32ErrorLogMessage(const char* file,
 732                                            int line,
 733                                            LogSeverity severity,
 734                                            SystemErrorCode err)
 735     : err_(err),
 736       log_message_(file, line, severity) {
 737 }
 738
 739 Win32ErrorLogMessage::~Win32ErrorLogMessage() {
 740   stream() << ": " << SystemErrorCodeToString(err_);
 741   // We're about to crash (CHECK). Put |err_| on the stack (by placing it in a
 742   // field) and use Alias in hopes that it makes it into crash dumps.
 743   DWORD last_error = err_;
 744   base::debug::Alias(&last_error);
 745 }
 746 #elif defined(OS_POSIX)
 747 ErrnoLogMessage::ErrnoLogMessage(const char* file,
 748                                  int line,
 749                                  LogSeverity severity,
 750                                  SystemErrorCode err)
 751     : err_(err),
 752       log_message_(file, line, severity) {
 753 }
 754
 755 ErrnoLogMessage::~ErrnoLogMessage() {
 756   stream() << ": " << SystemErrorCodeToString(err_);
 757 }
 758 #endif  // OS_WIN
 759
 760 void CloseLogFile() {
 761   LoggingLock logging_lock;
 762   CloseLogFileUnlocked();
 763 }
 764
 765 void RawLog(int level, const char* message) {
 766   if (level >= min_log_level) {
 767     size_t bytes_written = 0;
 768     const size_t message_len = strlen(message);
 769     int rv;
 770     while (bytes_written < message_len) {
 771       rv = HANDLE_EINTR(
 772           write(STDERR_FILENO, message + bytes_written,
 773                 message_len - bytes_written));
 774       if (rv < 0) {
 775         // Give up, nothing we can do now.
 776         break;
 777       }
 778       bytes_written += rv;
 779     }
 780
 781     if (message_len > 0 && message[message_len - 1] != '\n') {
 782       do {
 783         rv = HANDLE_EINTR(write(STDERR_FILENO, "\n", 1));
 784         if (rv < 0) {
 785           // Give up, nothing we can do now.
 786           break;
 787         }
 788       } while (rv != 1);
 789     }
 790   }
 791
 792   if (level == LOG_FATAL)
 793     base::debug::BreakDebugger();
 794 }
 795
 796 // This was defined at the beginning of this file.
 797 #undef write
 798
 799 #if defined(OS_WIN)
 800 std::wstring GetLogFileFullPath() {
 801   if (log_file_name)
 802     return *log_file_name;
 803   return std::wstring();
 804 }
 805 #endif
 806
 807 }  // namespace logging
 808
 809 std::ostream& std::operator<<(std::ostream& out, const wchar_t* wstr) {
 810   return out << base::WideToUTF8(wstr);
 811 }