logging.cc revision ddb351dbec246cf1fab5ec20d2d5520909041de1 
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>
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 <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
38typedef FILE* FileHandle;
39typedef 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
61namespace logging {
62
63DcheckState g_dcheck_state = DISABLE_DCHECK_FOR_NON_OFFICIAL_RELEASE_BUILDS;
64VlogInfo* g_vlog_info = NULL;
65
66const char* const log_severity_names[LOG_NUM_SEVERITIES] = {
67  "INFO", "WARNING", "ERROR", "ERROR_REPORT", "FATAL" };
68
69int 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)
76LoggingDestination logging_destination = LOG_ONLY_TO_FILE;
77#elif defined(OS_POSIX)
78LoggingDestination logging_destination = LOG_ONLY_TO_SYSTEM_DEBUG_LOG;
79#endif
80
81// For LOG_ERROR and above, always print to stderr.
82const 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)
88typedef std::wstring PathString;
89#else
90typedef std::string PathString;
91#endif
92PathString* log_file_name = NULL;
93
94// this file is lazily opened and the handle may be NULL
95FileHandle log_file = NULL;
96
97// what should be prepended to each message?
98bool log_process_id = false;
99bool log_thread_id = false;
100bool log_timestamp = true;
101bool log_tickcount = false;
102
103// Should we pop up fatal debug messages in a dialog?
104bool 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.
108LogAssertHandlerFunction log_assert_handler = NULL;
109// An report handler override specified by the client to be called instead of
110// the debug message dialog.
111LogReportHandlerFunction log_report_handler = NULL;
112// A log message handler that gets notified of every log message we process.
113LogMessageHandlerFunction log_message_handler = NULL;
114
115// Helper functions to wrap platform differences.
116
117int32 CurrentProcessId() {
118#if defined(OS_WIN)
119  return GetCurrentProcessId();
120#elif defined(OS_POSIX)
121  return getpid();
122#endif
123}
124
125int32 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
140uint64 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
161void CloseFile(FileHandle log) {
162#if defined(OS_WIN)
163  CloseHandle(log);
164#else
165  fclose(log);
166#endif
167}
168
169void 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
177PathString 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.
202class 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
296bool LoggingLock::initialized = false;
297// static
298base::internal::LockImpl* LoggingLock::log_lock = NULL;
299// static
300LogLockingState LoggingLock::lock_log_file = LOCK_LOG_FILE;
301
302#if defined(OS_WIN)
303// static
304MutexHandle LoggingLock::log_mutex = NULL;
305#elif defined(OS_POSIX)
306pthread_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.
312bool 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
349bool BaseInitLoggingImpl(const PathChar* new_log_file,
350                         LoggingDestination logging_dest,
351                         LogLockingState lock_log,
352                         OldFileDeletionState delete_old,
353                         DcheckState dcheck_state) {
354#ifdef ANDROID
355  // ifdef is here because we don't support parsing command line parameters
356  g_dcheck_state = dcheck_state;
357  g_vlog_info = NULL;
358#else
359  CommandLine* command_line = CommandLine::ForCurrentProcess();
360  g_dcheck_state = dcheck_state;
361  delete g_vlog_info;
362  g_vlog_info = NULL;
363  // Don't bother initializing g_vlog_info unless we use one of the
364  // vlog switches.
365  if (command_line->HasSwitch(switches::kV) ||
366      command_line->HasSwitch(switches::kVModule)) {
367    g_vlog_info =
368        new VlogInfo(command_line->GetSwitchValueASCII(switches::kV),
369                     command_line->GetSwitchValueASCII(switches::kVModule),
370                     &min_log_level);
371  }
372#endif
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
401void SetMinLogLevel(int level) {
402  min_log_level = std::min(LOG_ERROR_REPORT, level);
403}
404
405int GetMinLogLevel() {
406  return min_log_level;
407}
408
409int GetVlogVerbosity() {
410  return std::max(-1, LOG_INFO - GetMinLogLevel());
411}
412
413int 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
420void 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
428void SetShowErrorDialogs(bool enable_dialogs) {
429  show_error_dialogs = enable_dialogs;
430}
431
432void SetLogAssertHandler(LogAssertHandlerFunction handler) {
433  log_assert_handler = handler;
434}
435
436void SetLogReportHandler(LogReportHandlerFunction handler) {
437  log_report_handler = handler;
438}
439
440void SetLogMessageHandler(LogMessageHandlerFunction handler) {
441  log_message_handler = handler;
442}
443
444LogMessageHandlerFunction 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.
451template std::string* MakeCheckOpString<int, int>(
452    const int&, const int&, const char* names);
453template std::string* MakeCheckOpString<unsigned long, unsigned long>(
454    const unsigned long&, const unsigned long&, const char* names);
455template std::string* MakeCheckOpString<unsigned long, unsigned int>(
456    const unsigned long&, const unsigned int&, const char* names);
457template std::string* MakeCheckOpString<unsigned int, unsigned long>(
458    const unsigned int&, const unsigned long&, const char* names);
459template 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.
468void 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)
515LogMessage::SaveLastError::SaveLastError() : last_error_(::GetLastError()) {
516}
517
518LogMessage::SaveLastError::~SaveLastError() {
519  ::SetLastError(last_error_);
520}
521#endif  // defined(OS_WIN)
522
523LogMessage::LogMessage(const char* file, int line, LogSeverity severity,
524                       int ctr)
525    : severity_(severity), file_(file), line_(line) {
526  Init(file, line);
527}
528
529LogMessage::LogMessage(const char* file, int line)
530    : severity_(LOG_INFO), file_(file), line_(line) {
531  Init(file, line);
532}
533
534LogMessage::LogMessage(const char* file, int line, LogSeverity severity)
535    : severity_(severity), file_(file), line_(line) {
536  Init(file, line);
537}
538
539LogMessage::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
546LogMessage::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
554LogMessage::~LogMessage() {
555#ifndef NDEBUG
556  if (severity_ == LOG_FATAL) {
557    // Include a stack trace on a fatal.
558    base::debug::StackTrace trace;
559    stream_ << std::endl;  // Newline to separate from log message.
560    trace.OutputToStream(&stream_);
561  }
562#endif
563  stream_ << std::endl;
564  std::string str_newline(stream_.str());
565
566  // Give any log message handler first dibs on the message.
567  if (log_message_handler && log_message_handler(severity_, file_, line_,
568          message_start_, str_newline)) {
569    // The handler took care of it, no further processing.
570    return;
571  }
572
573  if (logging_destination == LOG_ONLY_TO_SYSTEM_DEBUG_LOG ||
574      logging_destination == LOG_TO_BOTH_FILE_AND_SYSTEM_DEBUG_LOG) {
575#if defined(OS_WIN)
576    OutputDebugStringA(str_newline.c_str());
577#endif
578    fprintf(stderr, "%s", str_newline.c_str());
579    fflush(stderr);
580  } else if (severity_ >= kAlwaysPrintErrorLevel) {
581    // When we're only outputting to a log file, above a certain log level, we
582    // should still output to stderr so that we can better detect and diagnose
583    // problems with unit tests, especially on the buildbots.
584    fprintf(stderr, "%s", str_newline.c_str());
585    fflush(stderr);
586  }
587
588  // We can have multiple threads and/or processes, so try to prevent them
589  // from clobbering each other's writes.
590  // If the client app did not call InitLogging, and the lock has not
591  // been created do it now. We do this on demand, but if two threads try
592  // to do this at the same time, there will be a race condition to create
593  // the lock. This is why InitLogging should be called from the main
594  // thread at the beginning of execution.
595  LoggingLock::Init(LOCK_LOG_FILE, NULL);
596  // write to log file
597  if (logging_destination != LOG_NONE &&
598      logging_destination != LOG_ONLY_TO_SYSTEM_DEBUG_LOG) {
599    LoggingLock logging_lock;
600    if (InitializeLogFileHandle()) {
601#if defined(OS_WIN)
602      SetFilePointer(log_file, 0, 0, SEEK_END);
603      DWORD num_written;
604      WriteFile(log_file,
605                static_cast<const void*>(str_newline.c_str()),
606                static_cast<DWORD>(str_newline.length()),
607                &num_written,
608                NULL);
609#else
610      fprintf(log_file, "%s", str_newline.c_str());
611      fflush(log_file);
612#endif
613    }
614  }
615
616  if (severity_ == LOG_FATAL) {
617    // display a message or break into the debugger on a fatal error
618    if (base::debug::BeingDebugged()) {
619      base::debug::BreakDebugger();
620    } else {
621      if (log_assert_handler) {
622        // make a copy of the string for the handler out of paranoia
623        log_assert_handler(std::string(stream_.str()));
624      } else {
625        // Don't use the string with the newline, get a fresh version to send to
626        // the debug message process. We also don't display assertions to the
627        // user in release mode. The enduser can't do anything with this
628        // information, and displaying message boxes when the application is
629        // hosed can cause additional problems.
630#ifndef NDEBUG
631        DisplayDebugMessageInDialog(stream_.str());
632#endif
633        // Crash the process to generate a dump.
634        base::debug::BreakDebugger();
635      }
636    }
637  } else if (severity_ == LOG_ERROR_REPORT) {
638    // We are here only if the user runs with --enable-dcheck in release mode.
639    if (log_report_handler) {
640      log_report_handler(std::string(stream_.str()));
641    } else {
642      DisplayDebugMessageInDialog(stream_.str());
643    }
644  }
645}
646
647// writes the common header info to the stream
648void LogMessage::Init(const char* file, int line) {
649  base::StringPiece filename(file);
650  size_t last_slash_pos = filename.find_last_of("\\/");
651  if (last_slash_pos != base::StringPiece::npos)
652    filename.remove_prefix(last_slash_pos + 1);
653
654  // TODO(darin): It might be nice if the columns were fixed width.
655
656  stream_ <<  '[';
657  if (log_process_id)
658    stream_ << CurrentProcessId() << ':';
659  if (log_thread_id)
660    stream_ << CurrentThreadId() << ':';
661  if (log_timestamp) {
662    time_t t = time(NULL);
663    struct tm local_time = {0};
664#if _MSC_VER >= 1400
665    localtime_s(&local_time, &t);
666#else
667    localtime_r(&t, &local_time);
668#endif
669    struct tm* tm_time = &local_time;
670    stream_ << std::setfill('0')
671            << std::setw(2) << 1 + tm_time->tm_mon
672            << std::setw(2) << tm_time->tm_mday
673            << '/'
674            << std::setw(2) << tm_time->tm_hour
675            << std::setw(2) << tm_time->tm_min
676            << std::setw(2) << tm_time->tm_sec
677            << ':';
678  }
679  if (log_tickcount)
680    stream_ << TickCount() << ':';
681  if (severity_ >= 0)
682    stream_ << log_severity_names[severity_];
683  else
684    stream_ << "VERBOSE" << -severity_;
685
686  stream_ << ":" << filename << "(" << line << ")] ";
687
688  message_start_ = stream_.tellp();
689}
690
691#if defined(OS_WIN)
692// This has already been defined in the header, but defining it again as DWORD
693// ensures that the type used in the header is equivalent to DWORD. If not,
694// the redefinition is a compile error.
695typedef DWORD SystemErrorCode;
696#endif
697
698SystemErrorCode GetLastSystemErrorCode() {
699#if defined(OS_WIN)
700  return ::GetLastError();
701#elif defined(OS_POSIX)
702  return errno;
703#else
704#error Not implemented
705#endif
706}
707
708#if defined(OS_WIN)
709Win32ErrorLogMessage::Win32ErrorLogMessage(const char* file,
710                                           int line,
711                                           LogSeverity severity,
712                                           SystemErrorCode err,
713                                           const char* module)
714    : err_(err),
715      module_(module),
716      log_message_(file, line, severity) {
717}
718
719Win32ErrorLogMessage::Win32ErrorLogMessage(const char* file,
720                                           int line,
721                                           LogSeverity severity,
722                                           SystemErrorCode err)
723    : err_(err),
724      module_(NULL),
725      log_message_(file, line, severity) {
726}
727
728Win32ErrorLogMessage::~Win32ErrorLogMessage() {
729  const int error_message_buffer_size = 256;
730  char msgbuf[error_message_buffer_size];
731  DWORD flags = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
732  HMODULE hmod;
733  if (module_) {
734    hmod = GetModuleHandleA(module_);
735    if (hmod) {
736      flags |= FORMAT_MESSAGE_FROM_HMODULE;
737    } else {
738      // This makes a nested Win32ErrorLogMessage. It will have module_ of NULL
739      // so it will not call GetModuleHandle, so recursive errors are
740      // impossible.
741      DPLOG(WARNING) << "Couldn't open module " << module_
742          << " for error message query";
743    }
744  } else {
745    hmod = NULL;
746  }
747  DWORD len = FormatMessageA(flags,
748                             hmod,
749                             err_,
750                             0,
751                             msgbuf,
752                             sizeof(msgbuf) / sizeof(msgbuf[0]),
753                             NULL);
754  if (len) {
755    while ((len > 0) &&
756           isspace(static_cast<unsigned char>(msgbuf[len - 1]))) {
757      msgbuf[--len] = 0;
758    }
759    stream() << ": " << msgbuf;
760  } else {
761    stream() << ": Error " << GetLastError() << " while retrieving error "
762        << err_;
763  }
764}
765#elif defined(OS_POSIX)
766ErrnoLogMessage::ErrnoLogMessage(const char* file,
767                                 int line,
768                                 LogSeverity severity,
769                                 SystemErrorCode err)
770    : err_(err),
771      log_message_(file, line, severity) {
772}
773
774ErrnoLogMessage::~ErrnoLogMessage() {
775  stream() << ": " << safe_strerror(err_);
776}
777#endif  // OS_WIN
778
779void CloseLogFile() {
780  LoggingLock logging_lock;
781
782  if (!log_file)
783    return;
784
785  CloseFile(log_file);
786  log_file = NULL;
787}
788
789void RawLog(int level, const char* message) {
790  if (level >= min_log_level) {
791    size_t bytes_written = 0;
792    const size_t message_len = strlen(message);
793    int rv;
794    while (bytes_written < message_len) {
795      rv = HANDLE_EINTR(
796          write(STDERR_FILENO, message + bytes_written,
797                message_len - bytes_written));
798      if (rv < 0) {
799        // Give up, nothing we can do now.
800        break;
801      }
802      bytes_written += rv;
803    }
804
805    if (message_len > 0 && message[message_len - 1] != '\n') {
806      do {
807        rv = HANDLE_EINTR(write(STDERR_FILENO, "\n", 1));
808        if (rv < 0) {
809          // Give up, nothing we can do now.
810          break;
811        }
812      } while (rv != 1);
813    }
814  }
815
816  if (level == LOG_FATAL)
817    base::debug::BreakDebugger();
818}
819
820}  // namespace logging
821
822std::ostream& operator<<(std::ostream& out, const wchar_t* wstr) {
823  return out << WideToUTF8(std::wstring(wstr));
824}
825
826namespace base {
827
828// This was defined at the beginnig of this file.
829#undef write
830
831std::ostream& operator<<(std::ostream& o, const StringPiece& piece) {
832  o.write(piece.data(), static_cast<std::streamsize>(piece.size()));
833  return o;
834}
835
836}  // namespace base
837