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/posix/safe_strerror.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 = nullptr;
  74 VlogInfo* g_vlog_info_prev = nullptr;
  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 g_min_log_level = 0;
  86
  87 LoggingDestination g_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* g_log_file_name = nullptr;
 101
 102 // This file is lazily opened and the handle may be nullptr
 103 FileHandle g_log_file = nullptr;
 104
 105 // What should be prepended to each message?
 106 bool g_log_process_id = false;
 107 bool g_log_thread_id = false;
 108 bool g_log_timestamp = true;
 109 bool g_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 = nullptr;
 117 // A log message handler that gets notified of every log message we process.
 118 LogMessageHandlerFunction log_message_handler = nullptr;
 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(nullptr, module_name, MAX_PATH);
 166
 167   PathString log_name = module_name;
 168   PathString::size_type last_backslash = log_name.rfind('\\', log_name.size());
 169   if (last_backslash != PathString::npos)
 170     log_name.erase(last_backslash + 1);
 171   log_name += L"debug.log";
 172   return log_name;
 173 #elif defined(OS_POSIX)
 174   // On other platforms we just use the current directory.
 175   return PathString("debug.log");
 176 #endif
 177 }
 178
 179 // This class acts as a wrapper for locking the logging files.
 180 // LoggingLock::Init() should be called from the main thread before any logging
 181 // is done. Then whenever logging, be sure to have a local LoggingLock
 182 // instance on the stack. This will ensure that the lock is unlocked upon
 183 // exiting the frame.
 184 // LoggingLocks can not be nested.
 185 class LoggingLock {
 186  public:
 187   LoggingLock() {
 188     LockLogging();
 189   }
 190
 191   ~LoggingLock() {
 192     UnlockLogging();
 193   }
 194
 195   static void Init(LogLockingState lock_log, const PathChar* new_log_file) {
 196     if (initialized)
 197       return;
 198     lock_log_file = lock_log;
 199     if (lock_log_file == LOCK_LOG_FILE) {
 200 #if defined(OS_WIN)
 201       if (!log_mutex) {
 202         std::wstring safe_name;
 203         if (new_log_file)
 204           safe_name = new_log_file;
 205         else
 206           safe_name = GetDefaultLogFile();
 207         // \ is not a legal character in mutex names so we replace \ with /
 208         std::replace(safe_name.begin(), safe_name.end(), '\\', '/');
 209         std::wstring t(L"Global\\");
 210         t.append(safe_name);
 211         log_mutex = ::CreateMutex(nullptr, FALSE, t.c_str());
 212
 213         if (log_mutex == nullptr) {
 214 #if DEBUG
 215           // Keep the error code for debugging
 216           int error = GetLastError();  // NOLINT
 217           base::debug::BreakDebugger();
 218 #endif
 219           // Return nicely without putting initialized to true.
 220           return;
 221         }
 222       }
 223 #endif
 224     } else {
 225       log_lock = new base::internal::LockImpl();
 226     }
 227     initialized = true;
 228   }
 229
 230  private:
 231   static void LockLogging() {
 232     if (lock_log_file == LOCK_LOG_FILE) {
 233 #if defined(OS_WIN)
 234       ::WaitForSingleObject(log_mutex, INFINITE);
 235       // WaitForSingleObject could have returned WAIT_ABANDONED. We don't
 236       // abort the process here. UI tests might be crashy sometimes,
 237       // and aborting the test binary only makes the problem worse.
 238       // We also don't use LOG macros because that might lead to an infinite
 239       // loop. For more info see http://crbug.com/18028.
 240 #elif defined(OS_POSIX)
 241       pthread_mutex_lock(&log_mutex);
 242 #endif
 243     } else {
 244       // use the lock
 245       log_lock->Lock();
 246     }
 247   }
 248
 249   static void UnlockLogging() {
 250     if (lock_log_file == LOCK_LOG_FILE) {
 251 #if defined(OS_WIN)
 252       ReleaseMutex(log_mutex);
 253 #elif defined(OS_POSIX)
 254       pthread_mutex_unlock(&log_mutex);
 255 #endif
 256     } else {
 257       log_lock->Unlock();
 258     }
 259   }
 260
 261   // The lock is used if log file locking is false. It helps us avoid problems
 262   // with multiple threads writing to the log file at the same time.  Use
 263   // LockImpl directly instead of using Lock, because Lock makes logging calls.
 264   static base::internal::LockImpl* log_lock;
 265
 266   // When we don't use a lock, we are using a global mutex. We need to do this
 267   // because LockFileEx is not thread safe.
 268 #if defined(OS_WIN)
 269   static MutexHandle log_mutex;
 270 #elif defined(OS_POSIX)
 271   static pthread_mutex_t log_mutex;
 272 #endif
 273
 274   static bool initialized;
 275   static LogLockingState lock_log_file;
 276 };
 277
 278 // static
 279 bool LoggingLock::initialized = false;
 280 // static
 281 base::internal::LockImpl* LoggingLock::log_lock = nullptr;
 282 // static
 283 LogLockingState LoggingLock::lock_log_file = LOCK_LOG_FILE;
 284
 285 #if defined(OS_WIN)
 286 // static
 287 MutexHandle LoggingLock::log_mutex = nullptr;
 288 #elif defined(OS_POSIX)
 289 pthread_mutex_t LoggingLock::log_mutex = PTHREAD_MUTEX_INITIALIZER;
 290 #endif
 291
 292 // Called by logging functions to ensure that |g_log_file| is initialized
 293 // and can be used for writing. Returns false if the file could not be
 294 // initialized. |g_log_file| will be nullptr in this case.
 295 bool InitializeLogFileHandle() {
 296   if (g_log_file)
 297     return true;
 298
 299   if (!g_log_file_name) {
 300     // Nobody has called InitLogging to specify a debug log file, so here we
 301     // initialize the log file name to a default.
 302     g_log_file_name = new PathString(GetDefaultLogFile());
 303   }
 304
 305   if ((g_logging_destination & LOG_TO_FILE) != 0) {
 306 #if defined(OS_WIN)
 307     g_log_file = CreateFile(g_log_file_name->c_str(), GENERIC_WRITE,
 308                             FILE_SHARE_READ | FILE_SHARE_WRITE, nullptr,
 309                             OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, nullptr);
 310     if (g_log_file == INVALID_HANDLE_VALUE || g_log_file == nullptr) {
 311       // try the current directory
 312       g_log_file = CreateFile(L".\\debug.log", GENERIC_WRITE,
 313                               FILE_SHARE_READ | FILE_SHARE_WRITE, nullptr,
 314                               OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, nullptr);
 315       if (g_log_file == INVALID_HANDLE_VALUE || g_log_file == nullptr) {
 316         g_log_file = nullptr;
 317         return false;
 318       }
 319     }
 320     SetFilePointer(g_log_file, 0, 0, FILE_END);
 321 #elif defined(OS_POSIX)
 322     g_log_file = fopen(g_log_file_name->c_str(), "a");
 323     if (g_log_file == nullptr)
 324       return false;
 325 #endif
 326   }
 327
 328   return true;
 329 }
 330
 331 void CloseFile(FileHandle log) {
 332 #if defined(OS_WIN)
 333   CloseHandle(log);
 334 #else
 335   fclose(log);
 336 #endif
 337 }
 338
 339 void CloseLogFileUnlocked() {
 340   if (!g_log_file)
 341     return;
 342
 343   CloseFile(g_log_file);
 344   g_log_file = nullptr;
 345 }
 346
 347 }  // namespace
 348
 349 LoggingSettings::LoggingSettings()
 350     : logging_dest(LOG_DEFAULT),
 351       log_file(nullptr),
 352       lock_log(LOCK_LOG_FILE),
 353       delete_old(APPEND_TO_OLD_LOG_FILE) {}
 354
 355 bool BaseInitLoggingImpl(const LoggingSettings& settings) {
 356 #if defined(OS_NACL)
 357   // Can log only to the system debug log.
 358   CHECK_EQ(settings.logging_dest & ~LOG_TO_SYSTEM_DEBUG_LOG, 0);
 359 #endif
 360   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
 361   // Don't bother initializing |g_vlog_info| unless we use one of the
 362   // vlog switches.
 363   if (command_line->HasSwitch(switches::kV) ||
 364       command_line->HasSwitch(switches::kVModule)) {
 365     // NOTE: If |g_vlog_info| has already been initialized, it might be in use
 366     // by another thread. Don't delete the old VLogInfo, just create a second
 367     // one. We keep track of both to avoid memory leak warnings.
 368     CHECK(!g_vlog_info_prev);
 369     g_vlog_info_prev = g_vlog_info;
 370
 371     g_vlog_info =
 372         new VlogInfo(command_line->GetSwitchValueASCII(switches::kV),
 373                      command_line->GetSwitchValueASCII(switches::kVModule),
 374                      &g_min_log_level);
 375   }
 376
 377   g_logging_destination = settings.logging_dest;
 378
 379   // ignore file options unless logging to file is set.
 380   if ((g_logging_destination & LOG_TO_FILE) == 0)
 381     return true;
 382
 383   LoggingLock::Init(settings.lock_log, settings.log_file);
 384   LoggingLock logging_lock;
 385
 386   // Calling InitLogging twice or after some log call has already opened the
 387   // default log file will re-initialize to the new options.
 388   CloseLogFileUnlocked();
 389
 390   if (!g_log_file_name)
 391     g_log_file_name = new PathString();
 392   *g_log_file_name = settings.log_file;
 393   if (settings.delete_old == DELETE_OLD_LOG_FILE)
 394     DeleteFilePath(*g_log_file_name);
 395
 396   return InitializeLogFileHandle();
 397 }
 398
 399 void SetMinLogLevel(int level) {
 400   g_min_log_level = std::min(LOG_FATAL, level);
 401 }
 402
 403 int GetMinLogLevel() {
 404   return g_min_log_level;
 405 }
 406
 407 int GetVlogVerbosity() {
 408   return std::max(-1, LOG_INFO - GetMinLogLevel());
 409 }
 410
 411 int GetVlogLevelHelper(const char* file, size_t N) {
 412   DCHECK_GT(N, 0U);
 413   // Note: |g_vlog_info| may change on a different thread during startup
 414   // (but will always be valid or nullptr).
 415   VlogInfo* vlog_info = g_vlog_info;
 416   return vlog_info ?
 417       vlog_info->GetVlogLevel(base::StringPiece(file, N - 1)) :
 418       GetVlogVerbosity();
 419 }
 420
 421 void SetLogItems(bool enable_process_id, bool enable_thread_id,
 422                  bool enable_timestamp, bool enable_tickcount) {
 423   g_log_process_id = enable_process_id;
 424   g_log_thread_id = enable_thread_id;
 425   g_log_timestamp = enable_timestamp;
 426   g_log_tickcount = enable_tickcount;
 427 }
 428
 429 void SetShowErrorDialogs(bool enable_dialogs) {
 430   show_error_dialogs = enable_dialogs;
 431 }
 432
 433 void SetLogAssertHandler(LogAssertHandlerFunction handler) {
 434   log_assert_handler = handler;
 435 }
 436
 437 void SetLogMessageHandler(LogMessageHandlerFunction handler) {
 438   log_message_handler = handler;
 439 }
 440
 441 LogMessageHandlerFunction GetLogMessageHandler() {
 442   return log_message_handler;
 443 }
 444
 445 // Explicit instantiations for commonly used comparisons.
 446 template std::string* MakeCheckOpString<int, int>(
 447     const int&, const int&, const char* names);
 448 template std::string* MakeCheckOpString<unsigned long, unsigned long>(
 449     const unsigned long&, const unsigned long&, const char* names);
 450 template std::string* MakeCheckOpString<unsigned long, unsigned int>(
 451     const unsigned long&, const unsigned int&, const char* names);
 452 template std::string* MakeCheckOpString<unsigned int, unsigned long>(
 453     const unsigned int&, const unsigned long&, const char* names);
 454 template std::string* MakeCheckOpString<std::string, std::string>(
 455     const std::string&, const std::string&, const char* name);
 456
 457 #if !defined(NDEBUG)
 458 // Displays a message box to the user with the error message in it.
 459 // Used for fatal messages, where we close the app simultaneously.
 460 // This is for developers only; we don't use this in circumstances
 461 // (like release builds) where users could see it, since users don't
 462 // understand these messages anyway.
 463 void DisplayDebugMessageInDialog(const std::string& str) {
 464   if (str.empty())
 465     return;
 466
 467   if (!show_error_dialogs)
 468     return;
 469
 470 #if defined(OS_WIN)
 471   // For Windows programs, it's possible that the message loop is
 472   // messed up on a fatal error, and creating a MessageBox will cause
 473   // that message loop to be run. Instead, we try to spawn another
 474   // process that displays its command line. We look for "Debug
 475   // Message.exe" in the same directory as the application. If it
 476   // exists, we use it, otherwise, we use a regular message box.
 477   wchar_t prog_name[MAX_PATH];
 478   GetModuleFileNameW(nullptr, prog_name, MAX_PATH);
 479   wchar_t* backslash = wcsrchr(prog_name, '\\');
 480   if (backslash)
 481     backslash[1] = 0;
 482   wcscat_s(prog_name, MAX_PATH, L"debug_message.exe");
 483
 484   std::wstring cmdline = base::UTF8ToWide(str);
 485   if (cmdline.empty())
 486     return;
 487
 488   STARTUPINFO startup_info;
 489   memset(&startup_info, 0, sizeof(startup_info));
 490   startup_info.cb = sizeof(startup_info);
 491
 492   PROCESS_INFORMATION process_info;
 493   if (CreateProcessW(prog_name, &cmdline[0], nullptr, nullptr, false, 0,
 494                      nullptr, nullptr, &startup_info, &process_info)) {
 495     WaitForSingleObject(process_info.hProcess, INFINITE);
 496     CloseHandle(process_info.hThread);
 497     CloseHandle(process_info.hProcess);
 498   } else {
 499     // debug process broken, let's just do a message box
 500     MessageBoxW(nullptr, &cmdline[0], L"Fatal error",
 501                 MB_OK | MB_ICONHAND | MB_TOPMOST);
 502   }
 503 #else
 504   // We intentionally don't implement a dialog on other platforms.
 505   // You can just look at stderr.
 506 #endif  // defined(OS_WIN)
 507 }
 508 #endif  // !defined(NDEBUG)
 509
 510 #if defined(OS_WIN)
 511 LogMessage::SaveLastError::SaveLastError() : last_error_(::GetLastError()) {
 512 }
 513
 514 LogMessage::SaveLastError::~SaveLastError() {
 515   ::SetLastError(last_error_);
 516 }
 517 #endif  // defined(OS_WIN)
 518
 519 LogMessage::LogMessage(const char* file, int line, LogSeverity severity)
 520     : severity_(severity), file_(file), line_(line) {
 521   Init(file, line);
 522 }
 523
 524 LogMessage::LogMessage(const char* file, int line, const char* condition)
 525     : severity_(LOG_FATAL), file_(file), line_(line) {
 526   Init(file, line);
 527   stream_ << "Check failed: " << condition << ". ";
 528 }
 529
 530 LogMessage::LogMessage(const char* file, int line, std::string* result)
 531     : severity_(LOG_FATAL), file_(file), line_(line) {
 532   Init(file, line);
 533   stream_ << "Check failed: " << *result;
 534   delete result;
 535 }
 536
 537 LogMessage::LogMessage(const char* file, int line, LogSeverity severity,
 538                        std::string* result)
 539     : severity_(severity), file_(file), line_(line) {
 540   Init(file, line);
 541   stream_ << "Check failed: " << *result;
 542   delete result;
 543 }
 544
 545 LogMessage::~LogMessage() {
 546 #if !defined(NDEBUG) && !defined(OS_NACL) && !defined(__UCLIBC__)
 547   if (severity_ == LOG_FATAL) {
 548     // Include a stack trace on a fatal.
 549     base::debug::StackTrace trace;
 550     stream_ << std::endl;  // Newline to separate from log message.
 551     trace.OutputToStream(&stream_);
 552   }
 553 #endif
 554   stream_ << std::endl;
 555   std::string str_newline(stream_.str());
 556
 557   // Give any log message handler first dibs on the message.
 558   if (log_message_handler &&
 559       log_message_handler(severity_, file_, line_,
 560                           message_start_, str_newline)) {
 561     // The handler took care of it, no further processing.
 562     return;
 563   }
 564
 565   if ((g_logging_destination & LOG_TO_SYSTEM_DEBUG_LOG) != 0) {
 566 #if defined(OS_WIN)
 567     OutputDebugStringA(str_newline.c_str());
 568 #elif defined(OS_ANDROID)
 569     android_LogPriority priority =
 570         (severity_ < 0) ? ANDROID_LOG_VERBOSE : ANDROID_LOG_UNKNOWN;
 571     switch (severity_) {
 572       case LOG_INFO:
 573         priority = ANDROID_LOG_INFO;
 574         break;
 575       case LOG_WARNING:
 576         priority = ANDROID_LOG_WARN;
 577         break;
 578       case LOG_ERROR:
 579         priority = ANDROID_LOG_ERROR;
 580         break;
 581       case LOG_FATAL:
 582         priority = ANDROID_LOG_FATAL;
 583         break;
 584     }
 585     __android_log_write(priority, "chromium", str_newline.c_str());
 586 #endif
 587     ignore_result(fwrite(str_newline.data(), str_newline.size(), 1, stderr));
 588     fflush(stderr);
 589   } else if (severity_ >= kAlwaysPrintErrorLevel) {
 590     // When we're only outputting to a log file, above a certain log level, we
 591     // should still output to stderr so that we can better detect and diagnose
 592     // problems with unit tests, especially on the buildbots.
 593     ignore_result(fwrite(str_newline.data(), str_newline.size(), 1, stderr));
 594     fflush(stderr);
 595   }
 596
 597   // write to log file
 598   if ((g_logging_destination & LOG_TO_FILE) != 0) {
 599     // We can have multiple threads and/or processes, so try to prevent them
 600     // from clobbering each other's writes.
 601     // If the client app did not call InitLogging, and the lock has not
 602     // been created do it now. We do this on demand, but if two threads try
 603     // to do this at the same time, there will be a race condition to create
 604     // the lock. This is why InitLogging should be called from the main
 605     // thread at the beginning of execution.
 606     LoggingLock::Init(LOCK_LOG_FILE, nullptr);
 607     LoggingLock logging_lock;
 608     if (InitializeLogFileHandle()) {
 609 #if defined(OS_WIN)
 610       SetFilePointer(g_log_file, 0, 0, SEEK_END);
 611       DWORD num_written;
 612       WriteFile(g_log_file,
 613                 static_cast<const void*>(str_newline.c_str()),
 614                 static_cast<DWORD>(str_newline.length()),
 615                 &num_written,
 616                 nullptr);
 617 #else
 618       ignore_result(fwrite(
 619           str_newline.data(), str_newline.size(), 1, g_log_file));
 620       fflush(g_log_file);
 621 #endif
 622     }
 623   }
 624
 625   if (severity_ == LOG_FATAL) {
 626     // Ensure the first characters of the string are on the stack so they
 627     // are contained in minidumps for diagnostic purposes.
 628     char str_stack[1024];
 629     str_newline.copy(str_stack, arraysize(str_stack));
 630     base::debug::Alias(str_stack);
 631
 632     if (log_assert_handler) {
 633       // Make a copy of the string for the handler out of paranoia.
 634       log_assert_handler(std::string(stream_.str()));
 635     } else {
 636       // Don't use the string with the newline, get a fresh version to send to
 637       // the debug message process. We also don't display assertions to the
 638       // user in release mode. The enduser can't do anything with this
 639       // information, and displaying message boxes when the application is
 640       // hosed can cause additional problems.
 641 #ifndef NDEBUG
 642       DisplayDebugMessageInDialog(stream_.str());
 643 #endif
 644       // Crash the process to generate a dump.
 645       base::debug::BreakDebugger();
 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 (g_log_process_id)
 661     stream_ << CurrentProcessId() << ':';
 662   if (g_log_thread_id)
 663     stream_ << base::PlatformThread::CurrentId() << ':';
 664   if (g_log_timestamp) {
 665     time_t t = time(nullptr);
 666     struct tm local_time = {0};
 667 #ifdef _MSC_VER
 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 (g_log_tickcount)
 683     stream_ << TickCount() << ':';
 684   if (severity_ >= 0)
 685     stream_ << log_severity_name(severity_);
 686   else
 687     stream_ << "VERBOSE" << -severity_;
 688
 689   stream_ << ":" << filename << "(" << line << ")] ";
 690
 691   message_start_ = stream_.str().length();
 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 BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code) {
 713   const int kErrorMessageBufferSize = 256;
 714   char msgbuf[kErrorMessageBufferSize];
 715   DWORD flags = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
 716   DWORD len = FormatMessageA(flags, nullptr, error_code, 0, msgbuf,
 717                              arraysize(msgbuf), nullptr);
 718   if (len) {
 719     // Messages returned by system end with line breaks.
 720     return base::CollapseWhitespaceASCII(msgbuf, true) +
 721         base::StringPrintf(" (0x%X)", error_code);
 722   }
 723   return base::StringPrintf("Error (0x%X) while retrieving error. (0x%X)",
 724                             GetLastError(), error_code);
 725 }
 726 #elif defined(OS_POSIX)
 727 BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code) {
 728   return base::safe_strerror(error_code);
 729 }
 730 #else
 731 #error Not implemented
 732 #endif  // defined(OS_WIN)
 733
 734
 735 #if defined(OS_WIN)
 736 Win32ErrorLogMessage::Win32ErrorLogMessage(const char* file,
 737                                            int line,
 738                                            LogSeverity severity,
 739                                            SystemErrorCode err)
 740     : err_(err),
 741       log_message_(file, line, severity) {
 742 }
 743
 744 Win32ErrorLogMessage::~Win32ErrorLogMessage() {
 745   stream() << ": " << SystemErrorCodeToString(err_);
 746   // We're about to crash (CHECK). Put |err_| on the stack (by placing it in a
 747   // field) and use Alias in hopes that it makes it into crash dumps.
 748   DWORD last_error = err_;
 749   base::debug::Alias(&last_error);
 750 }
 751 #elif defined(OS_POSIX)
 752 ErrnoLogMessage::ErrnoLogMessage(const char* file,
 753                                  int line,
 754                                  LogSeverity severity,
 755                                  SystemErrorCode err)
 756     : err_(err),
 757       log_message_(file, line, severity) {
 758 }
 759
 760 ErrnoLogMessage::~ErrnoLogMessage() {
 761   stream() << ": " << SystemErrorCodeToString(err_);
 762 }
 763 #endif  // defined(OS_WIN)
 764
 765 void CloseLogFile() {
 766   LoggingLock logging_lock;
 767   CloseLogFileUnlocked();
 768 }
 769
 770 void RawLog(int level, const char* message) {
 771   if (level >= g_min_log_level) {
 772     size_t bytes_written = 0;
 773     const size_t message_len = strlen(message);
 774     int rv;
 775     while (bytes_written < message_len) {
 776       rv = HANDLE_EINTR(
 777           write(STDERR_FILENO, message + bytes_written,
 778                 message_len - bytes_written));
 779       if (rv < 0) {
 780         // Give up, nothing we can do now.
 781         break;
 782       }
 783       bytes_written += rv;
 784     }
 785
 786     if (message_len > 0 && message[message_len - 1] != '\n') {
 787       do {
 788         rv = HANDLE_EINTR(write(STDERR_FILENO, "\n", 1));
 789         if (rv < 0) {
 790           // Give up, nothing we can do now.
 791           break;
 792         }
 793       } while (rv != 1);
 794     }
 795   }
 796
 797   if (level == LOG_FATAL)
 798     base::debug::BreakDebugger();
 799 }
 800
 801 // This was defined at the beginning of this file.
 802 #undef write
 803
 804 #if defined(OS_WIN)
 805 std::wstring GetLogFileFullPath() {
 806   if (g_log_file_name)
 807     return *g_log_file_name;
 808   return std::wstring();
 809 }
 810 #endif
 811
 812 BASE_EXPORT void LogErrorNotReached(const char* file, int line) {
 813   LogMessage(file, line, LOG_ERROR).stream()
 814       << "NOTREACHED() hit.";
 815 }
 816
 817 }  // namespace logging
 818
 819 std::ostream& std::operator<<(std::ostream& out, const wchar_t* wstr) {
 820   return out << base::WideToUTF8(wstr);
 821 }