logging.cc revision 21d179b334e59e9a3bfcaed4c4430bef1bc5759d 
1// Copyright (c) 2010 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>
10typedef HANDLE FileHandle;
11typedef 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 <CoreFoundation/CoreFoundation.h>
18#include <mach/mach.h>
19#include <mach/mach_time.h>
20#include <mach-o/dyld.h>
21#elif defined(OS_POSIX)
22#if defined(OS_NACL)
23#include <sys/nacl_syscalls.h>
24#include <sys/time.h> // timespec doesn't seem to be in <time.h>
25#else
26#include <sys/syscall.h>
27#endif
28#include <time.h>
29#endif
30
31#if defined(OS_POSIX)
32#include <errno.h>
33#include <pthread.h>
34#include <stdlib.h>
35#include <stdio.h>
36#include <string.h>
37#include <unistd.h>
38#define MAX_PATH PATH_MAX
39typedef FILE* FileHandle;
40typedef pthread_mutex_t* MutexHandle;
41#endif
42
43#include <ctime>
44#include <iomanip>
45#include <cstring>
46#include <algorithm>
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/lock_impl.h"
54#include "base/string_piece.h"
55#include "base/utf_string_conversions.h"
56#ifndef ANDROID
57#include "base/vlog.h"
58<<<<<<< HEAD
59=======
60#if defined(OS_POSIX)
61#include "base/safe_strerror_posix.h"
62#endif
63#if defined(OS_MACOSX)
64#include "base/mac/scoped_cftyperef.h"
65#include "base/sys_string_conversions.h"
66>>>>>>> chromium.org at r10.0.621.0
67#endif
68
69namespace logging {
70
71bool g_enable_dcheck = false;
72#ifndef ANDROID
73VlogInfo* g_vlog_info = NULL;
74#endif
75
76const char* const log_severity_names[LOG_NUM_SEVERITIES] = {
77  "INFO", "WARNING", "ERROR", "ERROR_REPORT", "FATAL" };
78
79int min_log_level = 0;
80
81// The default set here for logging_destination will only be used if
82// InitLogging is not called.  On Windows, use a file next to the exe;
83// on POSIX platforms, where it may not even be possible to locate the
84// executable on disk, use stderr.
85#if defined(OS_WIN)
86LoggingDestination logging_destination = LOG_ONLY_TO_FILE;
87#elif defined(OS_POSIX)
88LoggingDestination logging_destination = LOG_ONLY_TO_SYSTEM_DEBUG_LOG;
89#endif
90
91// For LOG_ERROR and above, always print to stderr.
92const int kAlwaysPrintErrorLevel = LOG_ERROR;
93
94// Which log file to use? This is initialized by InitLogging or
95// will be lazily initialized to the default value when it is
96// first needed.
97#if defined(OS_WIN)
98typedef std::wstring PathString;
99#else
100typedef std::string PathString;
101#endif
102PathString* log_file_name = NULL;
103
104// this file is lazily opened and the handle may be NULL
105FileHandle log_file = NULL;
106
107// what should be prepended to each message?
108bool log_process_id = false;
109bool log_thread_id = false;
110bool log_timestamp = true;
111bool log_tickcount = false;
112
113// Should we pop up fatal debug messages in a dialog?
114bool show_error_dialogs = false;
115
116// An assert handler override specified by the client to be called instead of
117// the debug message dialog and process termination.
118LogAssertHandlerFunction log_assert_handler = NULL;
119// An report handler override specified by the client to be called instead of
120// the debug message dialog.
121LogReportHandlerFunction log_report_handler = NULL;
122// A log message handler that gets notified of every log message we process.
123LogMessageHandlerFunction log_message_handler = NULL;
124
125// Helper functions to wrap platform differences.
126
127int32 CurrentProcessId() {
128#if defined(OS_WIN)
129  return GetCurrentProcessId();
130#elif defined(OS_POSIX)
131  return getpid();
132#endif
133}
134
135int32 CurrentThreadId() {
136#if defined(OS_WIN)
137  return GetCurrentThreadId();
138#elif defined(OS_MACOSX)
139  return mach_thread_self();
140#elif defined(OS_LINUX)
141  return syscall(__NR_gettid);
142#elif defined(OS_FREEBSD)
143  // TODO(BSD): find a better thread ID
144  return reinterpret_cast<int64>(pthread_self());
145#elif defined(OS_NACL)
146  return pthread_self();
147#endif
148}
149
150uint64 TickCount() {
151#if defined(OS_WIN)
152  return GetTickCount();
153#elif defined(OS_MACOSX)
154  return mach_absolute_time();
155#elif defined(OS_NACL)
156  // NaCl sadly does not have _POSIX_TIMERS enabled in sys/features.h
157  // So we have to use clock() for now.
158  return clock();
159#elif defined(OS_POSIX)
160  struct timespec ts;
161  clock_gettime(CLOCK_MONOTONIC, &ts);
162
163  uint64 absolute_micro =
164    static_cast<int64>(ts.tv_sec) * 1000000 +
165    static_cast<int64>(ts.tv_nsec) / 1000;
166
167  return absolute_micro;
168#endif
169}
170
171void CloseFile(FileHandle log) {
172#if defined(OS_WIN)
173  CloseHandle(log);
174#else
175  fclose(log);
176#endif
177}
178
179void DeleteFilePath(const PathString& log_name) {
180#if defined(OS_WIN)
181  DeleteFile(log_name.c_str());
182#else
183  unlink(log_name.c_str());
184#endif
185}
186
187PathString GetDefaultLogFile() {
188#if defined(OS_WIN)
189  // On Windows we use the same path as the exe.
190  wchar_t module_name[MAX_PATH];
191  GetModuleFileName(NULL, module_name, MAX_PATH);
192
193  PathString log_file = module_name;
194  PathString::size_type last_backslash =
195      log_file.rfind('\\', log_file.size());
196  if (last_backslash != PathString::npos)
197    log_file.erase(last_backslash + 1);
198  log_file += L"debug.log";
199  return log_file;
200#elif defined(OS_POSIX)
201  // On other platforms we just use the current directory.
202  return PathString("debug.log");
203#endif
204}
205
206// This class acts as a wrapper for locking the logging files.
207// LoggingLock::Init() should be called from the main thread before any logging
208// is done. Then whenever logging, be sure to have a local LoggingLock
209// instance on the stack. This will ensure that the lock is unlocked upon
210// exiting the frame.
211// LoggingLocks can not be nested.
212class LoggingLock {
213 public:
214  LoggingLock() {
215    LockLogging();
216  }
217
218  ~LoggingLock() {
219    UnlockLogging();
220  }
221
222  static void Init(LogLockingState lock_log, const PathChar* new_log_file) {
223    if (initialized)
224      return;
225    lock_log_file = lock_log;
226    if (lock_log_file == LOCK_LOG_FILE) {
227#if defined(OS_WIN)
228      if (!log_mutex) {
229        std::wstring safe_name;
230        if (new_log_file)
231          safe_name = new_log_file;
232        else
233          safe_name = GetDefaultLogFile();
234        // \ is not a legal character in mutex names so we replace \ with /
235        std::replace(safe_name.begin(), safe_name.end(), '\\', '/');
236        std::wstring t(L"Global\\");
237        t.append(safe_name);
238        log_mutex = ::CreateMutex(NULL, FALSE, t.c_str());
239
240        if (log_mutex == NULL) {
241#if DEBUG
242          // Keep the error code for debugging
243          int error = GetLastError();  // NOLINT
244          base::debug::BreakDebugger();
245#endif
246          // Return nicely without putting initialized to true.
247          return;
248        }
249      }
250#endif
251    } else {
252      log_lock = new LockImpl();
253    }
254    initialized = true;
255  }
256
257 private:
258  static void LockLogging() {
259    if (lock_log_file == LOCK_LOG_FILE) {
260#if defined(OS_WIN)
261      ::WaitForSingleObject(log_mutex, INFINITE);
262      // WaitForSingleObject could have returned WAIT_ABANDONED. We don't
263      // abort the process here. UI tests might be crashy sometimes,
264      // and aborting the test binary only makes the problem worse.
265      // We also don't use LOG macros because that might lead to an infinite
266      // loop. For more info see http://crbug.com/18028.
267#elif defined(OS_POSIX)
268      pthread_mutex_lock(&log_mutex);
269#endif
270    } else {
271      // use the lock
272      log_lock->Lock();
273    }
274  }
275
276  static void UnlockLogging() {
277    if (lock_log_file == LOCK_LOG_FILE) {
278#if defined(OS_WIN)
279      ReleaseMutex(log_mutex);
280#elif defined(OS_POSIX)
281      pthread_mutex_unlock(&log_mutex);
282#endif
283    } else {
284      log_lock->Unlock();
285    }
286  }
287
288  // The lock is used if log file locking is false. It helps us avoid problems
289  // with multiple threads writing to the log file at the same time.  Use
290  // LockImpl directly instead of using Lock, because Lock makes logging calls.
291  static LockImpl* log_lock;
292
293  // When we don't use a lock, we are using a global mutex. We need to do this
294  // because LockFileEx is not thread safe.
295#if defined(OS_WIN)
296  static MutexHandle log_mutex;
297#elif defined(OS_POSIX)
298  static pthread_mutex_t log_mutex;
299#endif
300
301  static bool initialized;
302  static LogLockingState lock_log_file;
303};
304
305// static
306bool LoggingLock::initialized = false;
307// static
308LockImpl* LoggingLock::log_lock = NULL;
309// static
310LogLockingState LoggingLock::lock_log_file = LOCK_LOG_FILE;
311
312#if defined(OS_WIN)
313// static
314MutexHandle LoggingLock::log_mutex = NULL;
315#elif defined(OS_POSIX)
316pthread_mutex_t LoggingLock::log_mutex = PTHREAD_MUTEX_INITIALIZER;
317#endif
318
319// Called by logging functions to ensure that debug_file is initialized
320// and can be used for writing. Returns false if the file could not be
321// initialized. debug_file will be NULL in this case.
322bool InitializeLogFileHandle() {
323  if (log_file)
324    return true;
325
326  if (!log_file_name) {
327    // Nobody has called InitLogging to specify a debug log file, so here we
328    // initialize the log file name to a default.
329    log_file_name = new PathString(GetDefaultLogFile());
330  }
331
332  if (logging_destination == LOG_ONLY_TO_FILE ||
333      logging_destination == LOG_TO_BOTH_FILE_AND_SYSTEM_DEBUG_LOG) {
334#if defined(OS_WIN)
335    log_file = CreateFile(log_file_name->c_str(), GENERIC_WRITE,
336                          FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
337                          OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
338    if (log_file == INVALID_HANDLE_VALUE || log_file == NULL) {
339      // try the current directory
340      log_file = CreateFile(L".\\debug.log", GENERIC_WRITE,
341                            FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
342                            OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
343      if (log_file == INVALID_HANDLE_VALUE || log_file == NULL) {
344        log_file = NULL;
345        return false;
346      }
347    }
348    SetFilePointer(log_file, 0, 0, FILE_END);
349#elif defined(OS_POSIX)
350    log_file = fopen(log_file_name->c_str(), "a");
351    if (log_file == NULL)
352      return false;
353#endif
354  }
355
356  return true;
357}
358
359bool BaseInitLoggingImpl(const PathChar* new_log_file,
360                         LoggingDestination logging_dest,
361                         LogLockingState lock_log,
362                         OldFileDeletionState delete_old) {
363#ifdef ANDROID
364  g_enable_dcheck = false;
365#else
366  CommandLine* command_line = CommandLine::ForCurrentProcess();
367  g_enable_dcheck =
368      command_line->HasSwitch(switches::kEnableDCHECK);
369  delete g_vlog_info;
370  g_vlog_info = NULL;
371  // Don't bother initializing g_vlog_info unless we use one of the
372  // vlog switches.
373  if (command_line->HasSwitch(switches::kV) ||
374      command_line->HasSwitch(switches::kVModule)) {
375    g_vlog_info =
376        new VlogInfo(command_line->GetSwitchValueASCII(switches::kV),
377                     command_line->GetSwitchValueASCII(switches::kVModule),
378                     &min_log_level);
379  }
380#endif
381
382  LoggingLock::Init(lock_log, new_log_file);
383
384  LoggingLock logging_lock;
385
386  if (log_file) {
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    CloseFile(log_file);
390    log_file = NULL;
391  }
392
393  logging_destination = logging_dest;
394
395  // ignore file options if logging is disabled or only to system
396  if (logging_destination == LOG_NONE ||
397      logging_destination == LOG_ONLY_TO_SYSTEM_DEBUG_LOG)
398    return true;
399
400  if (!log_file_name)
401    log_file_name = new PathString();
402  *log_file_name = new_log_file;
403  if (delete_old == DELETE_OLD_LOG_FILE)
404    DeleteFilePath(*log_file_name);
405
406  return InitializeLogFileHandle();
407}
408
409void SetMinLogLevel(int level) {
410  min_log_level = std::min(LOG_ERROR_REPORT, level);
411}
412
413int GetMinLogLevel() {
414  return min_log_level;
415}
416
417int GetVlogVerbosity() {
418  return std::max(-1, LOG_INFO - GetMinLogLevel());
419}
420
421int GetVlogLevelHelper(const char* file, size_t N) {
422#ifdef ANDROID
423  return 0;
424#else
425  DCHECK_GT(N, 0U);
426  return g_vlog_info ?
427      g_vlog_info->GetVlogLevel(base::StringPiece(file, N - 1)) :
428      GetVlogVerbosity();
429#endif
430}
431
432void SetLogItems(bool enable_process_id, bool enable_thread_id,
433                 bool enable_timestamp, bool enable_tickcount) {
434  log_process_id = enable_process_id;
435  log_thread_id = enable_thread_id;
436  log_timestamp = enable_timestamp;
437  log_tickcount = enable_tickcount;
438}
439
440void SetShowErrorDialogs(bool enable_dialogs) {
441  show_error_dialogs = enable_dialogs;
442}
443
444void SetLogAssertHandler(LogAssertHandlerFunction handler) {
445  log_assert_handler = handler;
446}
447
448void SetLogReportHandler(LogReportHandlerFunction handler) {
449  log_report_handler = handler;
450}
451
452void SetLogMessageHandler(LogMessageHandlerFunction handler) {
453  log_message_handler = handler;
454}
455
456LogMessageHandlerFunction GetLogMessageHandler() {
457  return log_message_handler;
458}
459
460// MSVC doesn't like complex extern templates and DLLs.
461#if !defined(COMPILER_MSVC)
462// Explicit instantiations for commonly used comparisons.
463template std::string* MakeCheckOpString<int, int>(
464    const int&, const int&, const char* names);
465template std::string* MakeCheckOpString<unsigned long, unsigned long>(
466    const unsigned long&, const unsigned long&, const char* names);
467template std::string* MakeCheckOpString<unsigned long, unsigned int>(
468    const unsigned long&, const unsigned int&, const char* names);
469template std::string* MakeCheckOpString<unsigned int, unsigned long>(
470    const unsigned int&, const unsigned long&, const char* names);
471template std::string* MakeCheckOpString<std::string, std::string>(
472    const std::string&, const std::string&, const char* name);
473#endif
474
475// Displays a message box to the user with the error message in it.
476// Used for fatal messages, where we close the app simultaneously.
477// This is for developers only; we don't use this in circumstances
478// (like release builds) where users could see it, since users don't
479// understand these messages anyway.
480void DisplayDebugMessageInDialog(const std::string& str) {
481  if (str.empty())
482    return;
483
484  if (!show_error_dialogs)
485    return;
486
487#if defined(OS_WIN)
488  // For Windows programs, it's possible that the message loop is
489  // messed up on a fatal error, and creating a MessageBox will cause
490  // that message loop to be run. Instead, we try to spawn another
491  // process that displays its command line. We look for "Debug
492  // Message.exe" in the same directory as the application. If it
493  // exists, we use it, otherwise, we use a regular message box.
494  wchar_t prog_name[MAX_PATH];
495  GetModuleFileNameW(NULL, prog_name, MAX_PATH);
496  wchar_t* backslash = wcsrchr(prog_name, '\\');
497  if (backslash)
498    backslash[1] = 0;
499  wcscat_s(prog_name, MAX_PATH, L"debug_message.exe");
500
501  std::wstring cmdline = UTF8ToWide(str);
502  if (cmdline.empty())
503    return;
504
505  STARTUPINFO startup_info;
506  memset(&startup_info, 0, sizeof(startup_info));
507  startup_info.cb = sizeof(startup_info);
508
509  PROCESS_INFORMATION process_info;
510  if (CreateProcessW(prog_name, &cmdline[0], NULL, NULL, false, 0, NULL,
511                     NULL, &startup_info, &process_info)) {
512    WaitForSingleObject(process_info.hProcess, INFINITE);
513    CloseHandle(process_info.hThread);
514    CloseHandle(process_info.hProcess);
515  } else {
516    // debug process broken, let's just do a message box
517    MessageBoxW(NULL, &cmdline[0], L"Fatal error",
518                MB_OK | MB_ICONHAND | MB_TOPMOST);
519  }
520#elif defined(OS_MACOSX)
521  base::mac::ScopedCFTypeRef<CFStringRef> message(
522      base::SysUTF8ToCFStringRef(str));
523  CFUserNotificationDisplayNotice(0, kCFUserNotificationStopAlertLevel,
524                                  NULL, NULL, NULL, CFSTR("Fatal Error"),
525                                  message, NULL);
526#else
527  // We intentionally don't implement a dialog on other platforms.
528  // You can just look at stderr.
529#endif
530}
531
532#if defined(OS_WIN)
533LogMessage::SaveLastError::SaveLastError() : last_error_(::GetLastError()) {
534}
535
536LogMessage::SaveLastError::~SaveLastError() {
537  ::SetLastError(last_error_);
538}
539#endif  // defined(OS_WIN)
540
541LogMessage::LogMessage(const char* file, int line, LogSeverity severity,
542                       int ctr)
543    : severity_(severity), file_(file), line_(line) {
544  Init(file, line);
545}
546
547LogMessage::LogMessage(const char* file, int line, const CheckOpString& result)
548    : severity_(LOG_FATAL), file_(file), line_(line) {
549  Init(file, line);
550  stream_ << "Check failed: " << (*result.str_);
551}
552
553LogMessage::LogMessage(const char* file, int line, LogSeverity severity,
554                       const CheckOpString& result)
555    : severity_(severity), file_(file), line_(line) {
556  Init(file, line);
557  stream_ << "Check failed: " << (*result.str_);
558}
559
560LogMessage::LogMessage(const char* file, int line)
561    : severity_(LOG_INFO), file_(file), line_(line) {
562  Init(file, line);
563}
564
565LogMessage::LogMessage(const char* file, int line, LogSeverity severity)
566    : severity_(severity), file_(file), line_(line) {
567  Init(file, line);
568}
569
570// writes the common header info to the stream
571void LogMessage::Init(const char* file, int line) {
572  base::StringPiece filename(file);
573  size_t last_slash_pos = filename.find_last_of("\\/");
574  if (last_slash_pos != base::StringPiece::npos)
575    filename.remove_prefix(last_slash_pos + 1);
576
577  // TODO(darin): It might be nice if the columns were fixed width.
578
579  stream_ <<  '[';
580  if (log_process_id)
581    stream_ << CurrentProcessId() << ':';
582  if (log_thread_id)
583    stream_ << CurrentThreadId() << ':';
584  if (log_timestamp) {
585    time_t t = time(NULL);
586    struct tm local_time = {0};
587#if _MSC_VER >= 1400
588    localtime_s(&local_time, &t);
589#else
590    localtime_r(&t, &local_time);
591#endif
592    struct tm* tm_time = &local_time;
593    stream_ << std::setfill('0')
594            << std::setw(2) << 1 + tm_time->tm_mon
595            << std::setw(2) << tm_time->tm_mday
596            << '/'
597            << std::setw(2) << tm_time->tm_hour
598            << std::setw(2) << tm_time->tm_min
599            << std::setw(2) << tm_time->tm_sec
600            << ':';
601  }
602  if (log_tickcount)
603    stream_ << TickCount() << ':';
604  if (severity_ >= 0)
605    stream_ << log_severity_names[severity_];
606  else
607    stream_ << "VERBOSE" << -severity_;
608
609  stream_ << ":" << filename << "(" << line << ")] ";
610
611  message_start_ = stream_.tellp();
612}
613
614LogMessage::~LogMessage() {
615#ifndef NDEBUG
616  if (severity_ == LOG_FATAL) {
617    // Include a stack trace on a fatal.
618    base::debug::StackTrace trace;
619    stream_ << std::endl;  // Newline to separate from log message.
620    trace.OutputToStream(&stream_);
621  }
622#endif
623  stream_ << std::endl;
624  std::string str_newline(stream_.str());
625
626  // Give any log message handler first dibs on the message.
627  if (log_message_handler && log_message_handler(severity_, file_, line_,
628          message_start_, str_newline)) {
629    // The handler took care of it, no further processing.
630    return;
631  }
632
633  if (logging_destination == LOG_ONLY_TO_SYSTEM_DEBUG_LOG ||
634      logging_destination == LOG_TO_BOTH_FILE_AND_SYSTEM_DEBUG_LOG) {
635#if defined(OS_WIN)
636    OutputDebugStringA(str_newline.c_str());
637#endif
638    fprintf(stderr, "%s", str_newline.c_str());
639    fflush(stderr);
640  } else if (severity_ >= kAlwaysPrintErrorLevel) {
641    // When we're only outputting to a log file, above a certain log level, we
642    // should still output to stderr so that we can better detect and diagnose
643    // problems with unit tests, especially on the buildbots.
644    fprintf(stderr, "%s", str_newline.c_str());
645    fflush(stderr);
646  }
647
648  // We can have multiple threads and/or processes, so try to prevent them
649  // from clobbering each other's writes.
650  // If the client app did not call InitLogging, and the lock has not
651  // been created do it now. We do this on demand, but if two threads try
652  // to do this at the same time, there will be a race condition to create
653  // the lock. This is why InitLogging should be called from the main
654  // thread at the beginning of execution.
655  LoggingLock::Init(LOCK_LOG_FILE, NULL);
656  // write to log file
657  if (logging_destination != LOG_NONE &&
658      logging_destination != LOG_ONLY_TO_SYSTEM_DEBUG_LOG) {
659    LoggingLock logging_lock;
660    if (InitializeLogFileHandle()) {
661#if defined(OS_WIN)
662      SetFilePointer(log_file, 0, 0, SEEK_END);
663      DWORD num_written;
664      WriteFile(log_file,
665                static_cast<const void*>(str_newline.c_str()),
666                static_cast<DWORD>(str_newline.length()),
667                &num_written,
668                NULL);
669#else
670      fprintf(log_file, "%s", str_newline.c_str());
671      fflush(log_file);
672#endif
673    }
674  }
675
676  if (severity_ == LOG_FATAL) {
677    // display a message or break into the debugger on a fatal error
678    if (base::debug::BeingDebugged()) {
679      base::debug::BreakDebugger();
680    } else {
681      if (log_assert_handler) {
682        // make a copy of the string for the handler out of paranoia
683        log_assert_handler(std::string(stream_.str()));
684      } else {
685        // Don't use the string with the newline, get a fresh version to send to
686        // the debug message process. We also don't display assertions to the
687        // user in release mode. The enduser can't do anything with this
688        // information, and displaying message boxes when the application is
689        // hosed can cause additional problems.
690#ifndef NDEBUG
691        DisplayDebugMessageInDialog(stream_.str());
692#endif
693        // Crash the process to generate a dump.
694        base::debug::BreakDebugger();
695      }
696    }
697  } else if (severity_ == LOG_ERROR_REPORT) {
698    // We are here only if the user runs with --enable-dcheck in release mode.
699    if (log_report_handler) {
700      log_report_handler(std::string(stream_.str()));
701    } else {
702      DisplayDebugMessageInDialog(stream_.str());
703    }
704  }
705}
706
707#if defined(OS_WIN)
708// This has already been defined in the header, but defining it again as DWORD
709// ensures that the type used in the header is equivalent to DWORD. If not,
710// the redefinition is a compile error.
711typedef DWORD SystemErrorCode;
712#endif
713
714SystemErrorCode GetLastSystemErrorCode() {
715#if defined(OS_WIN)
716  return ::GetLastError();
717#elif defined(OS_POSIX)
718  return errno;
719#else
720#error Not implemented
721#endif
722}
723
724#if defined(OS_WIN)
725Win32ErrorLogMessage::Win32ErrorLogMessage(const char* file,
726                                           int line,
727                                           LogSeverity severity,
728                                           SystemErrorCode err,
729                                           const char* module)
730    : err_(err),
731      module_(module),
732      log_message_(file, line, severity) {
733}
734
735Win32ErrorLogMessage::Win32ErrorLogMessage(const char* file,
736                                           int line,
737                                           LogSeverity severity,
738                                           SystemErrorCode err)
739    : err_(err),
740      module_(NULL),
741      log_message_(file, line, severity) {
742}
743
744Win32ErrorLogMessage::~Win32ErrorLogMessage() {
745  const int error_message_buffer_size = 256;
746  char msgbuf[error_message_buffer_size];
747  DWORD flags = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
748  HMODULE hmod;
749  if (module_) {
750    hmod = GetModuleHandleA(module_);
751    if (hmod) {
752      flags |= FORMAT_MESSAGE_FROM_HMODULE;
753    } else {
754      // This makes a nested Win32ErrorLogMessage. It will have module_ of NULL
755      // so it will not call GetModuleHandle, so recursive errors are
756      // impossible.
757      DPLOG(WARNING) << "Couldn't open module " << module_
758          << " for error message query";
759    }
760  } else {
761    hmod = NULL;
762  }
763  DWORD len = FormatMessageA(flags,
764                             hmod,
765                             err_,
766                             0,
767                             msgbuf,
768                             sizeof(msgbuf) / sizeof(msgbuf[0]),
769                             NULL);
770  if (len) {
771    while ((len > 0) &&
772           isspace(static_cast<unsigned char>(msgbuf[len - 1]))) {
773      msgbuf[--len] = 0;
774    }
775    stream() << ": " << msgbuf;
776  } else {
777    stream() << ": Error " << GetLastError() << " while retrieving error "
778        << err_;
779  }
780}
781#elif defined(OS_POSIX)
782ErrnoLogMessage::ErrnoLogMessage(const char* file,
783                                 int line,
784                                 LogSeverity severity,
785                                 SystemErrorCode err)
786    : err_(err),
787      log_message_(file, line, severity) {
788}
789
790ErrnoLogMessage::~ErrnoLogMessage() {
791  stream() << ": " << safe_strerror(err_);
792}
793#endif  // OS_WIN
794
795void CloseLogFile() {
796  LoggingLock logging_lock;
797
798  if (!log_file)
799    return;
800
801  CloseFile(log_file);
802  log_file = NULL;
803}
804
805void RawLog(int level, const char* message) {
806  if (level >= min_log_level) {
807    size_t bytes_written = 0;
808    const size_t message_len = strlen(message);
809    int rv;
810    while (bytes_written < message_len) {
811      rv = HANDLE_EINTR(
812          write(STDERR_FILENO, message + bytes_written,
813                message_len - bytes_written));
814      if (rv < 0) {
815        // Give up, nothing we can do now.
816        break;
817      }
818      bytes_written += rv;
819    }
820
821    if (message_len > 0 && message[message_len - 1] != '\n') {
822      do {
823        rv = HANDLE_EINTR(write(STDERR_FILENO, "\n", 1));
824        if (rv < 0) {
825          // Give up, nothing we can do now.
826          break;
827        }
828      } while (rv != 1);
829    }
830  }
831
832  if (level == LOG_FATAL)
833    base::debug::BreakDebugger();
834}
835
836}  // namespace logging
837
838std::ostream& operator<<(std::ostream& out, const wchar_t* wstr) {
839  return out << WideToUTF8(std::wstring(wstr));
840}
841