base/logging.cc

   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 DcheckState g_dcheck_state = DISABLE_DCHECK_FOR_NON_OFFICIAL_RELEASE_BUILDS;
  64 VlogInfo* g_vlog_info = NULL;
  65
  66 const char* const log_severity_names[LOG_NUM_SEVERITIES] = {
  67   "INFO", "WARNING", "ERROR", "ERROR_REPORT", "FATAL" };
  68
  69 int min_log_level = 0;
  70
  71 // The default set here for logging_destination will only be used if
  72 // InitLogging is not called.  On Windows, use a file next to the exe;
  73 // on POSIX platforms, where it may not even be possible to locate the
  74 // executable on disk, use stderr.
  75 #if defined(OS_WIN)
  76 LoggingDestination logging_destination = LOG_ONLY_TO_FILE;
  77 #elif defined(OS_POSIX)
  78 LoggingDestination logging_destination = LOG_ONLY_TO_SYSTEM_DEBUG_LOG;
  79 #endif
  80
  81 // For LOG_ERROR and above, always print to stderr.
  82 const int kAlwaysPrintErrorLevel = LOG_ERROR;
  83
  84 // Which log file to use? This is initialized by InitLogging or
  85 // will be lazily initialized to the default value when it is
  86 // first needed.
  87 #if defined(OS_WIN)
  88 typedef std::wstring PathString;
  89 #else
  90 typedef std::string PathString;
  91 #endif
  92 PathString* log_file_name = NULL;
  93
  94 // this file is lazily opened and the handle may be NULL
  95 FileHandle log_file = NULL;
  96
  97 // what should be prepended to each message?
  98 bool log_process_id = false;
  99 bool log_thread_id = false;
 100 bool log_timestamp = true;
 101 bool log_tickcount = false;
 102
 103 // Should we pop up fatal debug messages in a dialog?
 104 bool show_error_dialogs = false;
 105
 106 // An assert handler override specified by the client to be called instead of
 107 // the debug message dialog and process termination.
 108 LogAssertHandlerFunction log_assert_handler = NULL;
 109 // An report handler override specified by the client to be called instead of
 110 // the debug message dialog.
 111 LogReportHandlerFunction log_report_handler = NULL;
 112 // A log message handler that gets notified of every log message we process.
 113 LogMessageHandlerFunction log_message_handler = NULL;
 114
 115 // Helper functions to wrap platform differences.
 116
 117 int32 CurrentProcessId() {
 118 #if defined(OS_WIN)
 119   return GetCurrentProcessId();
 120 #elif defined(OS_POSIX)
 121   return getpid();
 122 #endif
 123 }
 124
 125 int32 CurrentThreadId() {
 126 #if defined(OS_WIN)
 127   return GetCurrentThreadId();
 128 #elif defined(OS_MACOSX)
 129   return mach_thread_self();
 130 #elif defined(OS_LINUX)
 131   return syscall(__NR_gettid);
 132 #elif defined(OS_FREEBSD)
 133   // TODO(BSD): find a better thread ID
 134   return reinterpret_cast<int64>(pthread_self());
 135 #elif defined(OS_NACL)
 136   return pthread_self();
 137 #endif
 138 }
 139
 140 uint64 TickCount() {
 141 #if defined(OS_WIN)
 142   return GetTickCount();
 143 #elif defined(OS_MACOSX)
 144   return mach_absolute_time();
 145 #elif defined(OS_NACL)
 146   // NaCl sadly does not have _POSIX_TIMERS enabled in sys/features.h
 147   // So we have to use clock() for now.
 148   return clock();
 149 #elif defined(OS_POSIX)
 150   struct timespec ts;
 151   clock_gettime(CLOCK_MONOTONIC, &ts);
 152
 153   uint64 absolute_micro =
 154     static_cast<int64>(ts.tv_sec) * 1000000 +
 155     static_cast<int64>(ts.tv_nsec) / 1000;
 156
 157   return absolute_micro;
 158 #endif
 159 }
 160
 161 void CloseFile(FileHandle log) {
 162 #if defined(OS_WIN)
 163   CloseHandle(log);
 164 #else
 165   fclose(log);
 166 #endif
 167 }
 168
 169 void DeleteFilePath(const PathString& log_name) {
 170 #if defined(OS_WIN)
 171   DeleteFile(log_name.c_str());
 172 #else
 173   unlink(log_name.c_str());
 174 #endif
 175 }
 176
 177 PathString GetDefaultLogFile() {
 178 #if defined(OS_WIN)
 179   // On Windows we use the same path as the exe.
 180   wchar_t module_name[MAX_PATH];
 181   GetModuleFileName(NULL, module_name, MAX_PATH);
 182
 183   PathString log_file = module_name;
 184   PathString::size_type last_backslash =
 185       log_file.rfind('\\', log_file.size());
 186   if (last_backslash != PathString::npos)
 187     log_file.erase(last_backslash + 1);
 188   log_file += L"debug.log";
 189   return log_file;
 190 #elif defined(OS_POSIX)
 191   // On other platforms we just use the current directory.
 192   return PathString("debug.log");
 193 #endif
 194 }
 195
 196 // This class acts as a wrapper for locking the logging files.
 197 // LoggingLock::Init() should be called from the main thread before any logging
 198 // is done. Then whenever logging, be sure to have a local LoggingLock
 199 // instance on the stack. This will ensure that the lock is unlocked upon
 200 // exiting the frame.
 201 // LoggingLocks can not be nested.
 202 class LoggingLock {
 203  public:
 204   LoggingLock() {
 205     LockLogging();
 206   }
 207
 208   ~LoggingLock() {
 209     UnlockLogging();
 210   }
 211
 212   static void Init(LogLockingState lock_log, const PathChar* new_log_file) {
 213     if (initialized)
 214       return;
 215     lock_log_file = lock_log;
 216     if (lock_log_file == LOCK_LOG_FILE) {
 217 #if defined(OS_WIN)
 218       if (!log_mutex) {
 219         std::wstring safe_name;
 220         if (new_log_file)
 221           safe_name = new_log_file;
 222         else
 223           safe_name = GetDefaultLogFile();
 224         // \ is not a legal character in mutex names so we replace \ with /
 225         std::replace(safe_name.begin(), safe_name.end(), '\\', '/');
 226         std::wstring t(L"Global\\");
 227         t.append(safe_name);
 228         log_mutex = ::CreateMutex(NULL, FALSE, t.c_str());
 229
 230         if (log_mutex == NULL) {
 231 #if DEBUG
 232           // Keep the error code for debugging
 233           int error = GetLastError();  // NOLINT
 234           base::debug::BreakDebugger();
 235 #endif
 236           // Return nicely without putting initialized to true.
 237           return;
 238         }
 239       }
 240 #endif
 241     } else {
 242       log_lock = new base::internal::LockImpl();
 243     }
 244     initialized = true;
 245   }
 246
 247  private:
 248   static void LockLogging() {
 249     if (lock_log_file == LOCK_LOG_FILE) {
 250 #if defined(OS_WIN)
 251       ::WaitForSingleObject(log_mutex, INFINITE);
 252       // WaitForSingleObject could have returned WAIT_ABANDONED. We don't
 253       // abort the process here. UI tests might be crashy sometimes,
 254       // and aborting the test binary only makes the problem worse.
 255       // We also don't use LOG macros because that might lead to an infinite
 256       // loop. For more info see http://crbug.com/18028.
 257 #elif defined(OS_POSIX)
 258       pthread_mutex_lock(&log_mutex);
 259 #endif
 260     } else {
 261       // use the lock
 262       log_lock->Lock();
 263     }
 264   }
 265
 266   static void UnlockLogging() {
 267     if (lock_log_file == LOCK_LOG_FILE) {
 268 #if defined(OS_WIN)
 269       ReleaseMutex(log_mutex);
 270 #elif defined(OS_POSIX)
 271       pthread_mutex_unlock(&log_mutex);
 272 #endif
 273     } else {
 274       log_lock->Unlock();
 275     }
 276   }
 277
 278   // The lock is used if log file locking is false. It helps us avoid problems
 279   // with multiple threads writing to the log file at the same time.  Use
 280   // LockImpl directly instead of using Lock, because Lock makes logging calls.
 281   static base::internal::LockImpl* log_lock;
 282
 283   // When we don't use a lock, we are using a global mutex. We need to do this
 284   // because LockFileEx is not thread safe.
 285 #if defined(OS_WIN)
 286   static MutexHandle log_mutex;
 287 #elif defined(OS_POSIX)
 288   static pthread_mutex_t log_mutex;
 289 #endif
 290
 291   static bool initialized;
 292   static LogLockingState lock_log_file;
 293 };
 294
 295 // static
 296 bool LoggingLock::initialized = false;
 297 // static
 298 base::internal::LockImpl* LoggingLock::log_lock = NULL;
 299 // static
 300 LogLockingState LoggingLock::lock_log_file = LOCK_LOG_FILE;
 301
 302 #if defined(OS_WIN)
 303 // static
 304 MutexHandle LoggingLock::log_mutex = NULL;
 305 #elif defined(OS_POSIX)
 306 pthread_mutex_t LoggingLock::log_mutex = PTHREAD_MUTEX_INITIALIZER;
 307 #endif
 308
 309 // Called by logging functions to ensure that debug_file is initialized
 310 // and can be used for writing. Returns false if the file could not be
 311 // initialized. debug_file will be NULL in this case.
 312 bool InitializeLogFileHandle() {
 313   if (log_file)
 314     return true;
 315
 316   if (!log_file_name) {
 317     // Nobody has called InitLogging to specify a debug log file, so here we
 318     // initialize the log file name to a default.
 319     log_file_name = new PathString(GetDefaultLogFile());
 320   }
 321
 322   if (logging_destination == LOG_ONLY_TO_FILE ||
 323       logging_destination == LOG_TO_BOTH_FILE_AND_SYSTEM_DEBUG_LOG) {
 324 #if defined(OS_WIN)
 325     log_file = CreateFile(log_file_name->c_str(), GENERIC_WRITE,
 326                           FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
 327                           OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
 328     if (log_file == INVALID_HANDLE_VALUE || log_file == NULL) {
 329       // try the current directory
 330       log_file = CreateFile(L".\\debug.log", GENERIC_WRITE,
 331                             FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
 332                             OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
 333       if (log_file == INVALID_HANDLE_VALUE || log_file == NULL) {
 334         log_file = NULL;
 335         return false;
 336       }
 337     }
 338     SetFilePointer(log_file, 0, 0, FILE_END);
 339 #elif defined(OS_POSIX)
 340     log_file = fopen(log_file_name->c_str(), "a");
 341     if (log_file == NULL)
 342       return false;
 343 #endif
 344   }
 345
 346   return true;
 347 }
 348
 349 bool BaseInitLoggingImpl(const PathChar* new_log_file,
 350                          LoggingDestination logging_dest,
 351                          LogLockingState lock_log,
 352                          OldFileDeletionState delete_old,
 353                          DcheckState dcheck_state) {
 354   CommandLine* command_line = CommandLine::ForCurrentProcess();
 355   g_dcheck_state = dcheck_state;
 356   delete g_vlog_info;
 357   g_vlog_info = NULL;
 358   // Don't bother initializing g_vlog_info unless we use one of the
 359   // vlog switches.
 360   if (command_line->HasSwitch(switches::kV) ||
 361       command_line->HasSwitch(switches::kVModule)) {
 362     g_vlog_info =
 363         new VlogInfo(command_line->GetSwitchValueASCII(switches::kV),
 364                      command_line->GetSwitchValueASCII(switches::kVModule),
 365                      &min_log_level);
 366   }
 367
 368   LoggingLock::Init(lock_log, new_log_file);
 369
 370   LoggingLock logging_lock;
 371
 372   if (log_file) {
 373     // calling InitLogging twice or after some log call has already opened the
 374     // default log file will re-initialize to the new options
 375     CloseFile(log_file);
 376     log_file = NULL;
 377   }
 378
 379   logging_destination = logging_dest;
 380
 381   // ignore file options if logging is disabled or only to system
 382   if (logging_destination == LOG_NONE ||
 383       logging_destination == LOG_ONLY_TO_SYSTEM_DEBUG_LOG)
 384     return true;
 385
 386   if (!log_file_name)
 387     log_file_name = new PathString();
 388   *log_file_name = new_log_file;
 389   if (delete_old == DELETE_OLD_LOG_FILE)
 390     DeleteFilePath(*log_file_name);
 391
 392   return InitializeLogFileHandle();
 393 }
 394
 395 void SetMinLogLevel(int level) {
 396   min_log_level = std::min(LOG_ERROR_REPORT, level);
 397 }
 398
 399 int GetMinLogLevel() {
 400   return min_log_level;
 401 }
 402
 403 int GetVlogVerbosity() {
 404   return std::max(-1, LOG_INFO - GetMinLogLevel());
 405 }
 406
 407 int GetVlogLevelHelper(const char* file, size_t N) {
 408   DCHECK_GT(N, 0U);
 409   return g_vlog_info ?
 410       g_vlog_info->GetVlogLevel(base::StringPiece(file, N - 1)) :
 411       GetVlogVerbosity();
 412 }
 413
 414 void SetLogItems(bool enable_process_id, bool enable_thread_id,
 415                  bool enable_timestamp, bool enable_tickcount) {
 416   log_process_id = enable_process_id;
 417   log_thread_id = enable_thread_id;
 418   log_timestamp = enable_timestamp;
 419   log_tickcount = enable_tickcount;
 420 }
 421
 422 void SetShowErrorDialogs(bool enable_dialogs) {
 423   show_error_dialogs = enable_dialogs;
 424 }
 425
 426 void SetLogAssertHandler(LogAssertHandlerFunction handler) {
 427   log_assert_handler = handler;
 428 }
 429
 430 void SetLogReportHandler(LogReportHandlerFunction handler) {
 431   log_report_handler = handler;
 432 }
 433
 434 void SetLogMessageHandler(LogMessageHandlerFunction handler) {
 435   log_message_handler = handler;
 436 }
 437
 438 LogMessageHandlerFunction GetLogMessageHandler() {
 439   return log_message_handler;
 440 }
 441
 442 // MSVC doesn't like complex extern templates and DLLs.
 443 #if !defined(COMPILER_MSVC)
 444 // Explicit instantiations for commonly used comparisons.
 445 template std::string* MakeCheckOpString<int, int>(
 446     const int&, const int&, const char* names);
 447 template std::string* MakeCheckOpString<unsigned long, unsigned long>(
 448     const unsigned long&, const unsigned long&, const char* names);
 449 template std::string* MakeCheckOpString<unsigned long, unsigned int>(
 450     const unsigned long&, const unsigned int&, const char* names);
 451 template std::string* MakeCheckOpString<unsigned int, unsigned long>(
 452     const unsigned int&, const unsigned long&, const char* names);
 453 template std::string* MakeCheckOpString<std::string, std::string>(
 454     const std::string&, const std::string&, const char* name);
 455 #endif
 456
 457 // Displays a message box to the user with the error message in it.
 458 // Used for fatal messages, where we close the app simultaneously.
 459 // This is for developers only; we don't use this in circumstances
 460 // (like release builds) where users could see it, since users don't
 461 // understand these messages anyway.
 462 void DisplayDebugMessageInDialog(const std::string& str) {
 463   if (str.empty())
 464     return;
 465
 466   if (!show_error_dialogs)
 467     return;
 468
 469 #if defined(OS_WIN)
 470   // For Windows programs, it's possible that the message loop is
 471   // messed up on a fatal error, and creating a MessageBox will cause
 472   // that message loop to be run. Instead, we try to spawn another
 473   // process that displays its command line. We look for "Debug
 474   // Message.exe" in the same directory as the application. If it
 475   // exists, we use it, otherwise, we use a regular message box.
 476   wchar_t prog_name[MAX_PATH];
 477   GetModuleFileNameW(NULL, prog_name, MAX_PATH);
 478   wchar_t* backslash = wcsrchr(prog_name, '\\');
 479   if (backslash)
 480     backslash[1] = 0;
 481   wcscat_s(prog_name, MAX_PATH, L"debug_message.exe");
 482
 483   std::wstring cmdline = UTF8ToWide(str);
 484   if (cmdline.empty())
 485     return;
 486
 487   STARTUPINFO startup_info;
 488   memset(&startup_info, 0, sizeof(startup_info));
 489   startup_info.cb = sizeof(startup_info);
 490
 491   PROCESS_INFORMATION process_info;
 492   if (CreateProcessW(prog_name, &cmdline[0], NULL, NULL, false, 0, NULL,
 493                      NULL, &startup_info, &process_info)) {
 494     WaitForSingleObject(process_info.hProcess, INFINITE);
 495     CloseHandle(process_info.hThread);
 496     CloseHandle(process_info.hProcess);
 497   } else {
 498     // debug process broken, let's just do a message box
 499     MessageBoxW(NULL, &cmdline[0], L"Fatal error",
 500                 MB_OK | MB_ICONHAND | MB_TOPMOST);
 501   }
 502 #else
 503   // We intentionally don't implement a dialog on other platforms.
 504   // You can just look at stderr.
 505 #endif
 506 }
 507
 508 #if defined(OS_WIN)
 509 LogMessage::SaveLastError::SaveLastError() : last_error_(::GetLastError()) {
 510 }
 511
 512 LogMessage::SaveLastError::~SaveLastError() {
 513   ::SetLastError(last_error_);
 514 }
 515 #endif  // defined(OS_WIN)
 516
 517 LogMessage::LogMessage(const char* file, int line, LogSeverity severity,
 518                        int ctr)
 519     : severity_(severity), file_(file), line_(line) {
 520   Init(file, line);
 521 }
 522
 523 LogMessage::LogMessage(const char* file, int line)
 524     : severity_(LOG_INFO), file_(file), line_(line) {
 525   Init(file, line);
 526 }
 527
 528 LogMessage::LogMessage(const char* file, int line, LogSeverity severity)
 529     : severity_(severity), file_(file), line_(line) {
 530   Init(file, line);
 531 }
 532
 533 LogMessage::LogMessage(const char* file, int line, std::string* result)
 534     : severity_(LOG_FATAL), file_(file), line_(line) {
 535   Init(file, line);
 536   stream_ << "Check failed: " << *result;
 537   delete result;
 538 }
 539
 540 LogMessage::LogMessage(const char* file, int line, LogSeverity severity,
 541                        std::string* result)
 542     : severity_(severity), file_(file), line_(line) {
 543   Init(file, line);
 544   stream_ << "Check failed: " << *result;
 545   delete result;
 546 }
 547
 548 LogMessage::~LogMessage() {
 549 #ifndef NDEBUG
 550   if (severity_ == LOG_FATAL) {
 551     // Include a stack trace on a fatal.
 552     base::debug::StackTrace trace;
 553     stream_ << std::endl;  // Newline to separate from log message.
 554     trace.OutputToStream(&stream_);
 555   }
 556 #endif
 557   stream_ << std::endl;
 558   std::string str_newline(stream_.str());
 559
 560   // Give any log message handler first dibs on the message.
 561   if (log_message_handler && log_message_handler(severity_, file_, line_,
 562           message_start_, str_newline)) {
 563     // The handler took care of it, no further processing.
 564     return;
 565   }
 566
 567   if (logging_destination == LOG_ONLY_TO_SYSTEM_DEBUG_LOG ||
 568       logging_destination == LOG_TO_BOTH_FILE_AND_SYSTEM_DEBUG_LOG) {
 569 #if defined(OS_WIN)
 570     OutputDebugStringA(str_newline.c_str());
 571 #endif
 572     fprintf(stderr, "%s", str_newline.c_str());
 573     fflush(stderr);
 574   } else if (severity_ >= kAlwaysPrintErrorLevel) {
 575     // When we're only outputting to a log file, above a certain log level, we
 576     // should still output to stderr so that we can better detect and diagnose
 577     // problems with unit tests, especially on the buildbots.
 578     fprintf(stderr, "%s", str_newline.c_str());
 579     fflush(stderr);
 580   }
 581
 582   // We can have multiple threads and/or processes, so try to prevent them
 583   // from clobbering each other's writes.
 584   // If the client app did not call InitLogging, and the lock has not
 585   // been created do it now. We do this on demand, but if two threads try
 586   // to do this at the same time, there will be a race condition to create
 587   // the lock. This is why InitLogging should be called from the main
 588   // thread at the beginning of execution.
 589   LoggingLock::Init(LOCK_LOG_FILE, NULL);
 590   // write to log file
 591   if (logging_destination != LOG_NONE &&
 592       logging_destination != LOG_ONLY_TO_SYSTEM_DEBUG_LOG) {
 593     LoggingLock logging_lock;
 594     if (InitializeLogFileHandle()) {
 595 #if defined(OS_WIN)
 596       SetFilePointer(log_file, 0, 0, SEEK_END);
 597       DWORD num_written;
 598       WriteFile(log_file,
 599                 static_cast<const void*>(str_newline.c_str()),
 600                 static_cast<DWORD>(str_newline.length()),
 601                 &num_written,
 602                 NULL);
 603 #else
 604       fprintf(log_file, "%s", str_newline.c_str());
 605       fflush(log_file);
 606 #endif
 607     }
 608   }
 609
 610   if (severity_ == LOG_FATAL) {
 611     // display a message or break into the debugger on a fatal error
 612     if (base::debug::BeingDebugged()) {
 613       base::debug::BreakDebugger();
 614     } else {
 615       if (log_assert_handler) {
 616         // make a copy of the string for the handler out of paranoia
 617         log_assert_handler(std::string(stream_.str()));
 618       } else {
 619         // Don't use the string with the newline, get a fresh version to send to
 620         // the debug message process. We also don't display assertions to the
 621         // user in release mode. The enduser can't do anything with this
 622         // information, and displaying message boxes when the application is
 623         // hosed can cause additional problems.
 624 #ifndef NDEBUG
 625         DisplayDebugMessageInDialog(stream_.str());
 626 #endif
 627         // Crash the process to generate a dump.
 628         base::debug::BreakDebugger();
 629       }
 630     }
 631   } else if (severity_ == LOG_ERROR_REPORT) {
 632     // We are here only if the user runs with --enable-dcheck in release mode.
 633     if (log_report_handler) {
 634       log_report_handler(std::string(stream_.str()));
 635     } else {
 636       DisplayDebugMessageInDialog(stream_.str());
 637     }
 638   }
 639 }
 640
 641 // writes the common header info to the stream
 642 void LogMessage::Init(const char* file, int line) {
 643   base::StringPiece filename(file);
 644   size_t last_slash_pos = filename.find_last_of("\\/");
 645   if (last_slash_pos != base::StringPiece::npos)
 646     filename.remove_prefix(last_slash_pos + 1);
 647
 648   // TODO(darin): It might be nice if the columns were fixed width.
 649
 650   stream_ <<  '[';
 651   if (log_process_id)
 652     stream_ << CurrentProcessId() << ':';
 653   if (log_thread_id)
 654     stream_ << CurrentThreadId() << ':';
 655   if (log_timestamp) {
 656     time_t t = time(NULL);
 657     struct tm local_time = {0};
 658 #if _MSC_VER >= 1400
 659     localtime_s(&local_time, &t);
 660 #else
 661     localtime_r(&t, &local_time);
 662 #endif
 663     struct tm* tm_time = &local_time;
 664     stream_ << std::setfill('0')
 665             << std::setw(2) << 1 + tm_time->tm_mon
 666             << std::setw(2) << tm_time->tm_mday
 667             << '/'
 668             << std::setw(2) << tm_time->tm_hour
 669             << std::setw(2) << tm_time->tm_min
 670             << std::setw(2) << tm_time->tm_sec
 671             << ':';
 672   }
 673   if (log_tickcount)
 674     stream_ << TickCount() << ':';
 675   if (severity_ >= 0)
 676     stream_ << log_severity_names[severity_];
 677   else
 678     stream_ << "VERBOSE" << -severity_;
 679
 680   stream_ << ":" << filename << "(" << line << ")] ";
 681
 682   message_start_ = stream_.tellp();
 683 }
 684
 685 #if defined(OS_WIN)
 686 // This has already been defined in the header, but defining it again as DWORD
 687 // ensures that the type used in the header is equivalent to DWORD. If not,
 688 // the redefinition is a compile error.
 689 typedef DWORD SystemErrorCode;
 690 #endif
 691
 692 SystemErrorCode GetLastSystemErrorCode() {
 693 #if defined(OS_WIN)
 694   return ::GetLastError();
 695 #elif defined(OS_POSIX)
 696   return errno;
 697 #else
 698 #error Not implemented
 699 #endif
 700 }
 701
 702 #if defined(OS_WIN)
 703 Win32ErrorLogMessage::Win32ErrorLogMessage(const char* file,
 704                                            int line,
 705                                            LogSeverity severity,
 706                                            SystemErrorCode err,
 707                                            const char* module)
 708     : err_(err),
 709       module_(module),
 710       log_message_(file, line, severity) {
 711 }
 712
 713 Win32ErrorLogMessage::Win32ErrorLogMessage(const char* file,
 714                                            int line,
 715                                            LogSeverity severity,
 716                                            SystemErrorCode err)
 717     : err_(err),
 718       module_(NULL),
 719       log_message_(file, line, severity) {
 720 }
 721
 722 Win32ErrorLogMessage::~Win32ErrorLogMessage() {
 723   const int error_message_buffer_size = 256;
 724   char msgbuf[error_message_buffer_size];
 725   DWORD flags = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
 726   HMODULE hmod;
 727   if (module_) {
 728     hmod = GetModuleHandleA(module_);
 729     if (hmod) {
 730       flags |= FORMAT_MESSAGE_FROM_HMODULE;
 731     } else {
 732       // This makes a nested Win32ErrorLogMessage. It will have module_ of NULL
 733       // so it will not call GetModuleHandle, so recursive errors are
 734       // impossible.
 735       DPLOG(WARNING) << "Couldn't open module " << module_
 736           << " for error message query";
 737     }
 738   } else {
 739     hmod = NULL;
 740   }
 741   DWORD len = FormatMessageA(flags,
 742                              hmod,
 743                              err_,
 744                              0,
 745                              msgbuf,
 746                              sizeof(msgbuf) / sizeof(msgbuf[0]),
 747                              NULL);
 748   if (len) {
 749     while ((len > 0) &&
 750            isspace(static_cast<unsigned char>(msgbuf[len - 1]))) {
 751       msgbuf[--len] = 0;
 752     }
 753     stream() << ": " << msgbuf;
 754   } else {
 755     stream() << ": Error " << GetLastError() << " while retrieving error "
 756         << err_;
 757   }
 758 }
 759 #elif defined(OS_POSIX)
 760 ErrnoLogMessage::ErrnoLogMessage(const char* file,
 761                                  int line,
 762                                  LogSeverity severity,
 763                                  SystemErrorCode err)
 764     : err_(err),
 765       log_message_(file, line, severity) {
 766 }
 767
 768 ErrnoLogMessage::~ErrnoLogMessage() {
 769   stream() << ": " << safe_strerror(err_);
 770 }
 771 #endif  // OS_WIN
 772
 773 void CloseLogFile() {
 774   LoggingLock logging_lock;
 775
 776   if (!log_file)
 777     return;
 778
 779   CloseFile(log_file);
 780   log_file = NULL;
 781 }
 782
 783 void RawLog(int level, const char* message) {
 784   if (level >= min_log_level) {
 785     size_t bytes_written = 0;
 786     const size_t message_len = strlen(message);
 787     int rv;
 788     while (bytes_written < message_len) {
 789       rv = HANDLE_EINTR(
 790           write(STDERR_FILENO, message + bytes_written,
 791                 message_len - bytes_written));
 792       if (rv < 0) {
 793         // Give up, nothing we can do now.
 794         break;
 795       }
 796       bytes_written += rv;
 797     }
 798
 799     if (message_len > 0 && message[message_len - 1] != '\n') {
 800       do {
 801         rv = HANDLE_EINTR(write(STDERR_FILENO, "\n", 1));
 802         if (rv < 0) {
 803           // Give up, nothing we can do now.
 804           break;
 805         }
 806       } while (rv != 1);
 807     }
 808   }
 809
 810   if (level == LOG_FATAL)
 811     base::debug::BreakDebugger();
 812 }
 813
 814 }  // namespace logging
 815
 816 std::ostream& operator<<(std::ostream& out, const wchar_t* wstr) {
 817   return out << WideToUTF8(std::wstring(wstr));
 818 }
 819
 820 namespace base {
 821
 822 // This was defined at the beginnig of this file.
 823 #undef write
 824
 825 std::ostream& operator<<(std::ostream& o, const StringPiece& piece) {
 826   o.write(piece.data(), static_cast<std::streamsize>(piece.size()));
 827   return o;
 828 }
 829
 830 }  // namespace base