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 #if defined(OS_ANDROID)
  62 #include <android/log.h>
  63 #endif
  64
  65 namespace logging {
  66
  67 DcheckState g_dcheck_state = DISABLE_DCHECK_FOR_NON_OFFICIAL_RELEASE_BUILDS;
  68 VlogInfo* g_vlog_info = NULL;
  69
  70 const char* const log_severity_names[LOG_NUM_SEVERITIES] = {
  71   "INFO", "WARNING", "ERROR", "ERROR_REPORT", "FATAL" };
  72
  73 int min_log_level = 0;
  74
  75 // The default set here for logging_destination will only be used if
  76 // InitLogging is not called.  On Windows, use a file next to the exe;
  77 // on POSIX platforms, where it may not even be possible to locate the
  78 // executable on disk, use stderr.
  79 #if defined(OS_WIN)
  80 LoggingDestination logging_destination = LOG_ONLY_TO_FILE;
  81 #elif defined(OS_POSIX)
  82 LoggingDestination logging_destination = LOG_ONLY_TO_SYSTEM_DEBUG_LOG;
  83 #endif
  84
  85 // For LOG_ERROR and above, always print to stderr.
  86 const int kAlwaysPrintErrorLevel = LOG_ERROR;
  87
  88 // Which log file to use? This is initialized by InitLogging or
  89 // will be lazily initialized to the default value when it is
  90 // first needed.
  91 #if defined(OS_WIN)
  92 typedef std::wstring PathString;
  93 #else
  94 typedef std::string PathString;
  95 #endif
  96 PathString* log_file_name = NULL;
  97
  98 // this file is lazily opened and the handle may be NULL
  99 FileHandle log_file = NULL;
 100
 101 // what should be prepended to each message?
 102 bool log_process_id = false;
 103 bool log_thread_id = false;
 104 bool log_timestamp = true;
 105 bool log_tickcount = false;
 106
 107 // Should we pop up fatal debug messages in a dialog?
 108 bool show_error_dialogs = false;
 109
 110 // An assert handler override specified by the client to be called instead of
 111 // the debug message dialog and process termination.
 112 LogAssertHandlerFunction log_assert_handler = NULL;
 113 // An report handler override specified by the client to be called instead of
 114 // the debug message dialog.
 115 LogReportHandlerFunction log_report_handler = NULL;
 116 // A log message handler that gets notified of every log message we process.
 117 LogMessageHandlerFunction log_message_handler = NULL;
 118
 119 // Helper functions to wrap platform differences.
 120
 121 int32 CurrentProcessId() {
 122 #if defined(OS_WIN)
 123   return GetCurrentProcessId();
 124 #elif defined(OS_POSIX)
 125   return getpid();
 126 #endif
 127 }
 128
 129 int32 CurrentThreadId() {
 130 #if defined(OS_WIN)
 131   return GetCurrentThreadId();
 132 #elif defined(OS_MACOSX)
 133   return mach_thread_self();
 134 #elif defined(OS_LINUX)
 135   return syscall(__NR_gettid);
 136 #elif defined(OS_ANDROID)
 137   return gettid();
 138 #elif defined(OS_FREEBSD)
 139   // TODO(BSD): find a better thread ID
 140   return reinterpret_cast<int64>(pthread_self());
 141 #elif defined(OS_NACL)
 142   return pthread_self();
 143 #endif
 144 }
 145
 146 uint64 TickCount() {
 147 #if defined(OS_WIN)
 148   return GetTickCount();
 149 #elif defined(OS_MACOSX)
 150   return mach_absolute_time();
 151 #elif defined(OS_NACL)
 152   // NaCl sadly does not have _POSIX_TIMERS enabled in sys/features.h
 153   // So we have to use clock() for now.
 154   return clock();
 155 #elif defined(OS_POSIX)
 156   struct timespec ts;
 157   clock_gettime(CLOCK_MONOTONIC, &ts);
 158
 159   uint64 absolute_micro =
 160     static_cast<int64>(ts.tv_sec) * 1000000 +
 161     static_cast<int64>(ts.tv_nsec) / 1000;
 162
 163   return absolute_micro;
 164 #endif
 165 }
 166
 167 void CloseFile(FileHandle log) {
 168 #if defined(OS_WIN)
 169   CloseHandle(log);
 170 #else
 171   fclose(log);
 172 #endif
 173 }
 174
 175 void DeleteFilePath(const PathString& log_name) {
 176 #if defined(OS_WIN)
 177   DeleteFile(log_name.c_str());
 178 #else
 179   unlink(log_name.c_str());
 180 #endif
 181 }
 182
 183 PathString GetDefaultLogFile() {
 184 #if defined(OS_WIN)
 185   // On Windows we use the same path as the exe.
 186   wchar_t module_name[MAX_PATH];
 187   GetModuleFileName(NULL, module_name, MAX_PATH);
 188
 189   PathString log_file = module_name;
 190   PathString::size_type last_backslash =
 191       log_file.rfind('\\', log_file.size());
 192   if (last_backslash != PathString::npos)
 193     log_file.erase(last_backslash + 1);
 194   log_file += L"debug.log";
 195   return log_file;
 196 #elif defined(OS_POSIX)
 197   // On other platforms we just use the current directory.
 198   return PathString("debug.log");
 199 #endif
 200 }
 201
 202 // This class acts as a wrapper for locking the logging files.
 203 // LoggingLock::Init() should be called from the main thread before any logging
 204 // is done. Then whenever logging, be sure to have a local LoggingLock
 205 // instance on the stack. This will ensure that the lock is unlocked upon
 206 // exiting the frame.
 207 // LoggingLocks can not be nested.
 208 class LoggingLock {
 209  public:
 210   LoggingLock() {
 211     LockLogging();
 212   }
 213
 214   ~LoggingLock() {
 215     UnlockLogging();
 216   }
 217
 218   static void Init(LogLockingState lock_log, const PathChar* new_log_file) {
 219     if (initialized)
 220       return;
 221     lock_log_file = lock_log;
 222     if (lock_log_file == LOCK_LOG_FILE) {
 223 #if defined(OS_WIN)
 224       if (!log_mutex) {
 225         std::wstring safe_name;
 226         if (new_log_file)
 227           safe_name = new_log_file;
 228         else
 229           safe_name = GetDefaultLogFile();
 230         // \ is not a legal character in mutex names so we replace \ with /
 231         std::replace(safe_name.begin(), safe_name.end(), '\\', '/');
 232         std::wstring t(L"Global\\");
 233         t.append(safe_name);
 234         log_mutex = ::CreateMutex(NULL, FALSE, t.c_str());
 235
 236         if (log_mutex == NULL) {
 237 #if DEBUG
 238           // Keep the error code for debugging
 239           int error = GetLastError();  // NOLINT
 240           base::debug::BreakDebugger();
 241 #endif
 242           // Return nicely without putting initialized to true.
 243           return;
 244         }
 245       }
 246 #endif
 247     } else {
 248       log_lock = new base::internal::LockImpl();
 249     }
 250     initialized = true;
 251   }
 252
 253  private:
 254   static void LockLogging() {
 255     if (lock_log_file == LOCK_LOG_FILE) {
 256 #if defined(OS_WIN)
 257       ::WaitForSingleObject(log_mutex, INFINITE);
 258       // WaitForSingleObject could have returned WAIT_ABANDONED. We don't
 259       // abort the process here. UI tests might be crashy sometimes,
 260       // and aborting the test binary only makes the problem worse.
 261       // We also don't use LOG macros because that might lead to an infinite
 262       // loop. For more info see http://crbug.com/18028.
 263 #elif defined(OS_POSIX)
 264       pthread_mutex_lock(&log_mutex);
 265 #endif
 266     } else {
 267       // use the lock
 268       log_lock->Lock();
 269     }
 270   }
 271
 272   static void UnlockLogging() {
 273     if (lock_log_file == LOCK_LOG_FILE) {
 274 #if defined(OS_WIN)
 275       ReleaseMutex(log_mutex);
 276 #elif defined(OS_POSIX)
 277       pthread_mutex_unlock(&log_mutex);
 278 #endif
 279     } else {
 280       log_lock->Unlock();
 281     }
 282   }
 283
 284   // The lock is used if log file locking is false. It helps us avoid problems
 285   // with multiple threads writing to the log file at the same time.  Use
 286   // LockImpl directly instead of using Lock, because Lock makes logging calls.
 287   static base::internal::LockImpl* log_lock;
 288
 289   // When we don't use a lock, we are using a global mutex. We need to do this
 290   // because LockFileEx is not thread safe.
 291 #if defined(OS_WIN)
 292   static MutexHandle log_mutex;
 293 #elif defined(OS_POSIX)
 294   static pthread_mutex_t log_mutex;
 295 #endif
 296
 297   static bool initialized;
 298   static LogLockingState lock_log_file;
 299 };
 300
 301 // static
 302 bool LoggingLock::initialized = false;
 303 // static
 304 base::internal::LockImpl* LoggingLock::log_lock = NULL;
 305 // static
 306 LogLockingState LoggingLock::lock_log_file = LOCK_LOG_FILE;
 307
 308 #if defined(OS_WIN)
 309 // static
 310 MutexHandle LoggingLock::log_mutex = NULL;
 311 #elif defined(OS_POSIX)
 312 pthread_mutex_t LoggingLock::log_mutex = PTHREAD_MUTEX_INITIALIZER;
 313 #endif
 314
 315 // Called by logging functions to ensure that debug_file is initialized
 316 // and can be used for writing. Returns false if the file could not be
 317 // initialized. debug_file will be NULL in this case.
 318 bool InitializeLogFileHandle() {
 319   if (log_file)
 320     return true;
 321
 322   if (!log_file_name) {
 323     // Nobody has called InitLogging to specify a debug log file, so here we
 324     // initialize the log file name to a default.
 325     log_file_name = new PathString(GetDefaultLogFile());
 326   }
 327
 328   if (logging_destination == LOG_ONLY_TO_FILE ||
 329       logging_destination == LOG_TO_BOTH_FILE_AND_SYSTEM_DEBUG_LOG) {
 330 #if defined(OS_WIN)
 331     log_file = CreateFile(log_file_name->c_str(), GENERIC_WRITE,
 332                           FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
 333                           OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
 334     if (log_file == INVALID_HANDLE_VALUE || log_file == NULL) {
 335       // try the current directory
 336       log_file = CreateFile(L".\\debug.log", GENERIC_WRITE,
 337                             FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
 338                             OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
 339       if (log_file == INVALID_HANDLE_VALUE || log_file == NULL) {
 340         log_file = NULL;
 341         return false;
 342       }
 343     }
 344     SetFilePointer(log_file, 0, 0, FILE_END);
 345 #elif defined(OS_POSIX)
 346     log_file = fopen(log_file_name->c_str(), "a");
 347     if (log_file == NULL)
 348       return false;
 349 #endif
 350   }
 351
 352   return true;
 353 }
 354
 355 bool BaseInitLoggingImpl(const PathChar* new_log_file,
 356                          LoggingDestination logging_dest,
 357                          LogLockingState lock_log,
 358                          OldFileDeletionState delete_old,
 359                          DcheckState dcheck_state) {
 360   CommandLine* command_line = CommandLine::ForCurrentProcess();
 361   g_dcheck_state = dcheck_state;
 362   delete g_vlog_info;
 363   g_vlog_info = NULL;
 364   // Don't bother initializing g_vlog_info unless we use one of the
 365   // vlog switches.
 366   if (command_line->HasSwitch(switches::kV) ||
 367       command_line->HasSwitch(switches::kVModule)) {
 368     g_vlog_info =
 369         new VlogInfo(command_line->GetSwitchValueASCII(switches::kV),
 370                      command_line->GetSwitchValueASCII(switches::kVModule),
 371                      &min_log_level);
 372   }
 373
 374   LoggingLock::Init(lock_log, new_log_file);
 375
 376   LoggingLock logging_lock;
 377
 378   if (log_file) {
 379     // calling InitLogging twice or after some log call has already opened the
 380     // default log file will re-initialize to the new options
 381     CloseFile(log_file);
 382     log_file = NULL;
 383   }
 384
 385   logging_destination = logging_dest;
 386
 387   // ignore file options if logging is disabled or only to system
 388   if (logging_destination == LOG_NONE ||
 389       logging_destination == LOG_ONLY_TO_SYSTEM_DEBUG_LOG)
 390     return true;
 391
 392   if (!log_file_name)
 393     log_file_name = new PathString();
 394   *log_file_name = new_log_file;
 395   if (delete_old == DELETE_OLD_LOG_FILE)
 396     DeleteFilePath(*log_file_name);
 397
 398   return InitializeLogFileHandle();
 399 }
 400
 401 void SetMinLogLevel(int level) {
 402   min_log_level = std::min(LOG_ERROR_REPORT, level);
 403 }
 404
 405 int GetMinLogLevel() {
 406   return min_log_level;
 407 }
 408
 409 int GetVlogVerbosity() {
 410   return std::max(-1, LOG_INFO - GetMinLogLevel());
 411 }
 412
 413 int GetVlogLevelHelper(const char* file, size_t N) {
 414   DCHECK_GT(N, 0U);
 415   return g_vlog_info ?
 416       g_vlog_info->GetVlogLevel(base::StringPiece(file, N - 1)) :
 417       GetVlogVerbosity();
 418 }
 419
 420 void SetLogItems(bool enable_process_id, bool enable_thread_id,
 421                  bool enable_timestamp, bool enable_tickcount) {
 422   log_process_id = enable_process_id;
 423   log_thread_id = enable_thread_id;
 424   log_timestamp = enable_timestamp;
 425   log_tickcount = enable_tickcount;
 426 }
 427
 428 void SetShowErrorDialogs(bool enable_dialogs) {
 429   show_error_dialogs = enable_dialogs;
 430 }
 431
 432 void SetLogAssertHandler(LogAssertHandlerFunction handler) {
 433   log_assert_handler = handler;
 434 }
 435
 436 void SetLogReportHandler(LogReportHandlerFunction handler) {
 437   log_report_handler = handler;
 438 }
 439
 440 void SetLogMessageHandler(LogMessageHandlerFunction handler) {
 441   log_message_handler = handler;
 442 }
 443
 444 LogMessageHandlerFunction GetLogMessageHandler() {
 445   return log_message_handler;
 446 }
 447
 448 // MSVC doesn't like complex extern templates and DLLs.
 449 #if !defined(COMPILER_MSVC)
 450 // Explicit instantiations for commonly used comparisons.
 451 template std::string* MakeCheckOpString<int, int>(
 452     const int&, const int&, const char* names);
 453 template std::string* MakeCheckOpString<unsigned long, unsigned long>(
 454     const unsigned long&, const unsigned long&, const char* names);
 455 template std::string* MakeCheckOpString<unsigned long, unsigned int>(
 456     const unsigned long&, const unsigned int&, const char* names);
 457 template std::string* MakeCheckOpString<unsigned int, unsigned long>(
 458     const unsigned int&, const unsigned long&, const char* names);
 459 template std::string* MakeCheckOpString<std::string, std::string>(
 460     const std::string&, const std::string&, const char* name);
 461 #endif
 462
 463 // Displays a message box to the user with the error message in it.
 464 // Used for fatal messages, where we close the app simultaneously.
 465 // This is for developers only; we don't use this in circumstances
 466 // (like release builds) where users could see it, since users don't
 467 // understand these messages anyway.
 468 void DisplayDebugMessageInDialog(const std::string& str) {
 469   if (str.empty())
 470     return;
 471
 472   if (!show_error_dialogs)
 473     return;
 474
 475 #if defined(OS_WIN)
 476   // For Windows programs, it's possible that the message loop is
 477   // messed up on a fatal error, and creating a MessageBox will cause
 478   // that message loop to be run. Instead, we try to spawn another
 479   // process that displays its command line. We look for "Debug
 480   // Message.exe" in the same directory as the application. If it
 481   // exists, we use it, otherwise, we use a regular message box.
 482   wchar_t prog_name[MAX_PATH];
 483   GetModuleFileNameW(NULL, prog_name, MAX_PATH);
 484   wchar_t* backslash = wcsrchr(prog_name, '\\');
 485   if (backslash)
 486     backslash[1] = 0;
 487   wcscat_s(prog_name, MAX_PATH, L"debug_message.exe");
 488
 489   std::wstring cmdline = UTF8ToWide(str);
 490   if (cmdline.empty())
 491     return;
 492
 493   STARTUPINFO startup_info;
 494   memset(&startup_info, 0, sizeof(startup_info));
 495   startup_info.cb = sizeof(startup_info);
 496
 497   PROCESS_INFORMATION process_info;
 498   if (CreateProcessW(prog_name, &cmdline[0], NULL, NULL, false, 0, NULL,
 499                      NULL, &startup_info, &process_info)) {
 500     WaitForSingleObject(process_info.hProcess, INFINITE);
 501     CloseHandle(process_info.hThread);
 502     CloseHandle(process_info.hProcess);
 503   } else {
 504     // debug process broken, let's just do a message box
 505     MessageBoxW(NULL, &cmdline[0], L"Fatal error",
 506                 MB_OK | MB_ICONHAND | MB_TOPMOST);
 507   }
 508 #else
 509   // We intentionally don't implement a dialog on other platforms.
 510   // You can just look at stderr.
 511 #endif
 512 }
 513
 514 #if defined(OS_WIN)
 515 LogMessage::SaveLastError::SaveLastError() : last_error_(::GetLastError()) {
 516 }
 517
 518 LogMessage::SaveLastError::~SaveLastError() {
 519   ::SetLastError(last_error_);
 520 }
 521 #endif  // defined(OS_WIN)
 522
 523 LogMessage::LogMessage(const char* file, int line, LogSeverity severity,
 524                        int ctr)
 525     : severity_(severity), file_(file), line_(line) {
 526   Init(file, line);
 527 }
 528
 529 LogMessage::LogMessage(const char* file, int line)
 530     : severity_(LOG_INFO), file_(file), line_(line) {
 531   Init(file, line);
 532 }
 533
 534 LogMessage::LogMessage(const char* file, int line, LogSeverity severity)
 535     : severity_(severity), file_(file), line_(line) {
 536   Init(file, line);
 537 }
 538
 539 LogMessage::LogMessage(const char* file, int line, std::string* result)
 540     : severity_(LOG_FATAL), file_(file), line_(line) {
 541   Init(file, line);
 542   stream_ << "Check failed: " << *result;
 543   delete result;
 544 }
 545
 546 LogMessage::LogMessage(const char* file, int line, LogSeverity severity,
 547                        std::string* result)
 548     : severity_(severity), file_(file), line_(line) {
 549   Init(file, line);
 550   stream_ << "Check failed: " << *result;
 551   delete result;
 552 }
 553
 554 LogMessage::~LogMessage() {
 555   // TODO(port): enable stacktrace generation on LOG_FATAL once backtrace are
 556   // working in Android.
 557 #if  !defined(NDEBUG) && !defined(OS_ANDROID)
 558   if (severity_ == LOG_FATAL) {
 559     // Include a stack trace on a fatal.
 560     base::debug::StackTrace trace;
 561     stream_ << std::endl;  // Newline to separate from log message.
 562     trace.OutputToStream(&stream_);
 563   }
 564 #endif
 565   stream_ << std::endl;
 566   std::string str_newline(stream_.str());
 567
 568   // Give any log message handler first dibs on the message.
 569   if (log_message_handler && log_message_handler(severity_, file_, line_,
 570           message_start_, str_newline)) {
 571     // The handler took care of it, no further processing.
 572     return;
 573   }
 574
 575   if (logging_destination == LOG_ONLY_TO_SYSTEM_DEBUG_LOG ||
 576       logging_destination == LOG_TO_BOTH_FILE_AND_SYSTEM_DEBUG_LOG) {
 577 #if defined(OS_WIN)
 578     OutputDebugStringA(str_newline.c_str());
 579 #elif defined(OS_ANDROID)
 580     android_LogPriority priority = ANDROID_LOG_UNKNOWN;
 581     switch (severity_) {
 582       case LOG_INFO:
 583         priority = ANDROID_LOG_INFO;
 584         break;
 585       case LOG_WARNING:
 586         priority = ANDROID_LOG_WARN;
 587         break;
 588       case LOG_ERROR:
 589       case LOG_ERROR_REPORT:
 590         priority = ANDROID_LOG_ERROR;
 591         break;
 592       case LOG_FATAL:
 593         priority = ANDROID_LOG_FATAL;
 594         break;
 595     }
 596     __android_log_write(priority, "chromium", str_newline.c_str());
 597 #endif
 598     fprintf(stderr, "%s", str_newline.c_str());
 599     fflush(stderr);
 600   } else if (severity_ >= kAlwaysPrintErrorLevel) {
 601     // When we're only outputting to a log file, above a certain log level, we
 602     // should still output to stderr so that we can better detect and diagnose
 603     // problems with unit tests, especially on the buildbots.
 604     fprintf(stderr, "%s", str_newline.c_str());
 605     fflush(stderr);
 606   }
 607
 608   // We can have multiple threads and/or processes, so try to prevent them
 609   // from clobbering each other's writes.
 610   // If the client app did not call InitLogging, and the lock has not
 611   // been created do it now. We do this on demand, but if two threads try
 612   // to do this at the same time, there will be a race condition to create
 613   // the lock. This is why InitLogging should be called from the main
 614   // thread at the beginning of execution.
 615   LoggingLock::Init(LOCK_LOG_FILE, NULL);
 616   // write to log file
 617   if (logging_destination != LOG_NONE &&
 618       logging_destination != LOG_ONLY_TO_SYSTEM_DEBUG_LOG) {
 619     LoggingLock logging_lock;
 620     if (InitializeLogFileHandle()) {
 621 #if defined(OS_WIN)
 622       SetFilePointer(log_file, 0, 0, SEEK_END);
 623       DWORD num_written;
 624       WriteFile(log_file,
 625                 static_cast<const void*>(str_newline.c_str()),
 626                 static_cast<DWORD>(str_newline.length()),
 627                 &num_written,
 628                 NULL);
 629 #else
 630       fprintf(log_file, "%s", str_newline.c_str());
 631       fflush(log_file);
 632 #endif
 633     }
 634   }
 635
 636   if (severity_ == LOG_FATAL) {
 637     // display a message or break into the debugger on a fatal error
 638     if (base::debug::BeingDebugged()) {
 639       base::debug::BreakDebugger();
 640     } else {
 641       if (log_assert_handler) {
 642         // make a copy of the string for the handler out of paranoia
 643         log_assert_handler(std::string(stream_.str()));
 644       } else {
 645         // Don't use the string with the newline, get a fresh version to send to
 646         // the debug message process. We also don't display assertions to the
 647         // user in release mode. The enduser can't do anything with this
 648         // information, and displaying message boxes when the application is
 649         // hosed can cause additional problems.
 650 #ifndef NDEBUG
 651         DisplayDebugMessageInDialog(stream_.str());
 652 #endif
 653         // Crash the process to generate a dump.
 654         base::debug::BreakDebugger();
 655       }
 656     }
 657   } else if (severity_ == LOG_ERROR_REPORT) {
 658     // We are here only if the user runs with --enable-dcheck in release mode.
 659     if (log_report_handler) {
 660       log_report_handler(std::string(stream_.str()));
 661     } else {
 662       DisplayDebugMessageInDialog(stream_.str());
 663     }
 664   }
 665 }
 666
 667 // writes the common header info to the stream
 668 void LogMessage::Init(const char* file, int line) {
 669   base::StringPiece filename(file);
 670   size_t last_slash_pos = filename.find_last_of("\\/");
 671   if (last_slash_pos != base::StringPiece::npos)
 672     filename.remove_prefix(last_slash_pos + 1);
 673
 674   // TODO(darin): It might be nice if the columns were fixed width.
 675
 676   stream_ <<  '[';
 677   if (log_process_id)
 678     stream_ << CurrentProcessId() << ':';
 679   if (log_thread_id)
 680     stream_ << CurrentThreadId() << ':';
 681   if (log_timestamp) {
 682     time_t t = time(NULL);
 683     struct tm local_time = {0};
 684 #if _MSC_VER >= 1400
 685     localtime_s(&local_time, &t);
 686 #else
 687     localtime_r(&t, &local_time);
 688 #endif
 689     struct tm* tm_time = &local_time;
 690     stream_ << std::setfill('0')
 691             << std::setw(2) << 1 + tm_time->tm_mon
 692             << std::setw(2) << tm_time->tm_mday
 693             << '/'
 694             << std::setw(2) << tm_time->tm_hour
 695             << std::setw(2) << tm_time->tm_min
 696             << std::setw(2) << tm_time->tm_sec
 697             << ':';
 698   }
 699   if (log_tickcount)
 700     stream_ << TickCount() << ':';
 701   if (severity_ >= 0)
 702     stream_ << log_severity_names[severity_];
 703   else
 704     stream_ << "VERBOSE" << -severity_;
 705
 706   stream_ << ":" << filename << "(" << line << ")] ";
 707
 708   message_start_ = stream_.tellp();
 709 }
 710
 711 #if defined(OS_WIN)
 712 // This has already been defined in the header, but defining it again as DWORD
 713 // ensures that the type used in the header is equivalent to DWORD. If not,
 714 // the redefinition is a compile error.
 715 typedef DWORD SystemErrorCode;
 716 #endif
 717
 718 SystemErrorCode GetLastSystemErrorCode() {
 719 #if defined(OS_WIN)
 720   return ::GetLastError();
 721 #elif defined(OS_POSIX)
 722   return errno;
 723 #else
 724 #error Not implemented
 725 #endif
 726 }
 727
 728 #if defined(OS_WIN)
 729 Win32ErrorLogMessage::Win32ErrorLogMessage(const char* file,
 730                                            int line,
 731                                            LogSeverity severity,
 732                                            SystemErrorCode err,
 733                                            const char* module)
 734     : err_(err),
 735       module_(module),
 736       log_message_(file, line, severity) {
 737 }
 738
 739 Win32ErrorLogMessage::Win32ErrorLogMessage(const char* file,
 740                                            int line,
 741                                            LogSeverity severity,
 742                                            SystemErrorCode err)
 743     : err_(err),
 744       module_(NULL),
 745       log_message_(file, line, severity) {
 746 }
 747
 748 Win32ErrorLogMessage::~Win32ErrorLogMessage() {
 749   const int error_message_buffer_size = 256;
 750   char msgbuf[error_message_buffer_size];
 751   DWORD flags = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
 752   HMODULE hmod;
 753   if (module_) {
 754     hmod = GetModuleHandleA(module_);
 755     if (hmod) {
 756       flags |= FORMAT_MESSAGE_FROM_HMODULE;
 757     } else {
 758       // This makes a nested Win32ErrorLogMessage. It will have module_ of NULL
 759       // so it will not call GetModuleHandle, so recursive errors are
 760       // impossible.
 761       DPLOG(WARNING) << "Couldn't open module " << module_
 762           << " for error message query";
 763     }
 764   } else {
 765     hmod = NULL;
 766   }
 767   DWORD len = FormatMessageA(flags,
 768                              hmod,
 769                              err_,
 770                              0,
 771                              msgbuf,
 772                              sizeof(msgbuf) / sizeof(msgbuf[0]),
 773                              NULL);
 774   if (len) {
 775     while ((len > 0) &&
 776            isspace(static_cast<unsigned char>(msgbuf[len - 1]))) {
 777       msgbuf[--len] = 0;
 778     }
 779     stream() << ": " << msgbuf;
 780   } else {
 781     stream() << ": Error " << GetLastError() << " while retrieving error "
 782         << err_;
 783   }
 784 }
 785 #elif defined(OS_POSIX)
 786 ErrnoLogMessage::ErrnoLogMessage(const char* file,
 787                                  int line,
 788                                  LogSeverity severity,
 789                                  SystemErrorCode err)
 790     : err_(err),
 791       log_message_(file, line, severity) {
 792 }
 793
 794 ErrnoLogMessage::~ErrnoLogMessage() {
 795   stream() << ": " << safe_strerror(err_);
 796 }
 797 #endif  // OS_WIN
 798
 799 void CloseLogFile() {
 800   LoggingLock logging_lock;
 801
 802   if (!log_file)
 803     return;
 804
 805   CloseFile(log_file);
 806   log_file = NULL;
 807 }
 808
 809 void RawLog(int level, const char* message) {
 810   if (level >= min_log_level) {
 811     size_t bytes_written = 0;
 812     const size_t message_len = strlen(message);
 813     int rv;
 814     while (bytes_written < message_len) {
 815       rv = HANDLE_EINTR(
 816           write(STDERR_FILENO, message + bytes_written,
 817                 message_len - bytes_written));
 818       if (rv < 0) {
 819         // Give up, nothing we can do now.
 820         break;
 821       }
 822       bytes_written += rv;
 823     }
 824
 825     if (message_len > 0 && message[message_len - 1] != '\n') {
 826       do {
 827         rv = HANDLE_EINTR(write(STDERR_FILENO, "\n", 1));
 828         if (rv < 0) {
 829           // Give up, nothing we can do now.
 830           break;
 831         }
 832       } while (rv != 1);
 833     }
 834   }
 835
 836   if (level == LOG_FATAL)
 837     base::debug::BreakDebugger();
 838 }
 839
 840 }  // namespace logging
 841
 842 std::ostream& operator<<(std::ostream& out, const wchar_t* wstr) {
 843   return out << WideToUTF8(std::wstring(wstr));
 844 }
 845
 846 namespace base {
 847
 848 // This was defined at the beginnig of this file.
 849 #undef write
 850
 851 std::ostream& operator<<(std::ostream& o, const StringPiece& piece) {
 852   o.write(piece.data(), static_cast<std::streamsize>(piece.size()));
 853   return o;
 854 }
 855
 856 }  // namespace base