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>
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/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
37typedef FILE* FileHandle;
38typedef 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/safe_strerror_posix.h"
63#endif
64
65#if defined(OS_ANDROID)
66#include <android/log.h>
67#endif
68
69namespace logging {
70
71namespace {
72
73VlogInfo* g_vlog_info = NULL;
74VlogInfo* g_vlog_info_prev = NULL;
75
76const char* const log_severity_names[LOG_NUM_SEVERITIES] = {
77  "INFO", "WARNING", "ERROR", "FATAL" };
78
79const char* log_severity_name(int severity)
80{
81  if (severity >= 0 && severity < LOG_NUM_SEVERITIES)
82    return log_severity_names[severity];
83  return "UNKNOWN";
84}
85
86int min_log_level = 0;
87
88LoggingDestination logging_destination = LOG_DEFAULT;
89
90// For LOG_ERROR and above, always print to stderr.
91const int kAlwaysPrintErrorLevel = LOG_ERROR;
92
93// Which log file to use? This is initialized by InitLogging or
94// will be lazily initialized to the default value when it is
95// first needed.
96#if defined(OS_WIN)
97typedef std::wstring PathString;
98#else
99typedef std::string PathString;
100#endif
101PathString* log_file_name = NULL;
102
103// this file is lazily opened and the handle may be NULL
104FileHandle log_file = NULL;
105
106// what should be prepended to each message?
107bool log_process_id = false;
108bool log_thread_id = false;
109bool log_timestamp = true;
110bool log_tickcount = false;
111
112// Should we pop up fatal debug messages in a dialog?
113bool show_error_dialogs = false;
114
115// An assert handler override specified by the client to be called instead of
116// the debug message dialog and process termination.
117LogAssertHandlerFunction log_assert_handler = NULL;
118// A log message handler that gets notified of every log message we process.
119LogMessageHandlerFunction log_message_handler = NULL;
120
121// Helper functions to wrap platform differences.
122
123int32 CurrentProcessId() {
124#if defined(OS_WIN)
125  return GetCurrentProcessId();
126#elif defined(OS_POSIX)
127  return getpid();
128#endif
129}
130
131uint64 TickCount() {
132#if defined(OS_WIN)
133  return GetTickCount();
134#elif defined(OS_MACOSX)
135  return mach_absolute_time();
136#elif defined(OS_NACL)
137  // NaCl sadly does not have _POSIX_TIMERS enabled in sys/features.h
138  // So we have to use clock() for now.
139  return clock();
140#elif defined(OS_POSIX)
141  struct timespec ts;
142  clock_gettime(CLOCK_MONOTONIC, &ts);
143
144  uint64 absolute_micro =
145    static_cast<int64>(ts.tv_sec) * 1000000 +
146    static_cast<int64>(ts.tv_nsec) / 1000;
147
148  return absolute_micro;
149#endif
150}
151
152void DeleteFilePath(const PathString& log_name) {
153#if defined(OS_WIN)
154  DeleteFile(log_name.c_str());
155#elif defined (OS_NACL)
156  // Do nothing; unlink() isn't supported on NaCl.
157#else
158  unlink(log_name.c_str());
159#endif
160}
161
162PathString GetDefaultLogFile() {
163#if defined(OS_WIN)
164  // On Windows we use the same path as the exe.
165  wchar_t module_name[MAX_PATH];
166  GetModuleFileName(NULL, module_name, MAX_PATH);
167
168  PathString log_file = module_name;
169  PathString::size_type last_backslash =
170      log_file.rfind('\\', log_file.size());
171  if (last_backslash != PathString::npos)
172    log_file.erase(last_backslash + 1);
173  log_file += L"debug.log";
174  return log_file;
175#elif defined(OS_POSIX)
176  // On other platforms we just use the current directory.
177  return PathString("debug.log");
178#endif
179}
180
181// This class acts as a wrapper for locking the logging files.
182// LoggingLock::Init() should be called from the main thread before any logging
183// is done. Then whenever logging, be sure to have a local LoggingLock
184// instance on the stack. This will ensure that the lock is unlocked upon
185// exiting the frame.
186// LoggingLocks can not be nested.
187class LoggingLock {
188 public:
189  LoggingLock() {
190    LockLogging();
191  }
192
193  ~LoggingLock() {
194    UnlockLogging();
195  }
196
197  static void Init(LogLockingState lock_log, const PathChar* new_log_file) {
198    if (initialized)
199      return;
200    lock_log_file = lock_log;
201    if (lock_log_file == LOCK_LOG_FILE) {
202#if defined(OS_WIN)
203      if (!log_mutex) {
204        std::wstring safe_name;
205        if (new_log_file)
206          safe_name = new_log_file;
207        else
208          safe_name = GetDefaultLogFile();
209        // \ is not a legal character in mutex names so we replace \ with /
210        std::replace(safe_name.begin(), safe_name.end(), '\\', '/');
211        std::wstring t(L"Global\\");
212        t.append(safe_name);
213        log_mutex = ::CreateMutex(NULL, FALSE, t.c_str());
214
215        if (log_mutex == NULL) {
216#if DEBUG
217          // Keep the error code for debugging
218          int error = GetLastError();  // NOLINT
219          base::debug::BreakDebugger();
220#endif
221          // Return nicely without putting initialized to true.
222          return;
223        }
224      }
225#endif
226    } else {
227      log_lock = new base::internal::LockImpl();
228    }
229    initialized = true;
230  }
231
232 private:
233  static void LockLogging() {
234    if (lock_log_file == LOCK_LOG_FILE) {
235#if defined(OS_WIN)
236      ::WaitForSingleObject(log_mutex, INFINITE);
237      // WaitForSingleObject could have returned WAIT_ABANDONED. We don't
238      // abort the process here. UI tests might be crashy sometimes,
239      // and aborting the test binary only makes the problem worse.
240      // We also don't use LOG macros because that might lead to an infinite
241      // loop. For more info see http://crbug.com/18028.
242#elif defined(OS_POSIX)
243      pthread_mutex_lock(&log_mutex);
244#endif
245    } else {
246      // use the lock
247      log_lock->Lock();
248    }
249  }
250
251  static void UnlockLogging() {
252    if (lock_log_file == LOCK_LOG_FILE) {
253#if defined(OS_WIN)
254      ReleaseMutex(log_mutex);
255#elif defined(OS_POSIX)
256      pthread_mutex_unlock(&log_mutex);
257#endif
258    } else {
259      log_lock->Unlock();
260    }
261  }
262
263  // The lock is used if log file locking is false. It helps us avoid problems
264  // with multiple threads writing to the log file at the same time.  Use
265  // LockImpl directly instead of using Lock, because Lock makes logging calls.
266  static base::internal::LockImpl* log_lock;
267
268  // When we don't use a lock, we are using a global mutex. We need to do this
269  // because LockFileEx is not thread safe.
270#if defined(OS_WIN)
271  static MutexHandle log_mutex;
272#elif defined(OS_POSIX)
273  static pthread_mutex_t log_mutex;
274#endif
275
276  static bool initialized;
277  static LogLockingState lock_log_file;
278};
279
280// static
281bool LoggingLock::initialized = false;
282// static
283base::internal::LockImpl* LoggingLock::log_lock = NULL;
284// static
285LogLockingState LoggingLock::lock_log_file = LOCK_LOG_FILE;
286
287#if defined(OS_WIN)
288// static
289MutexHandle LoggingLock::log_mutex = NULL;
290#elif defined(OS_POSIX)
291pthread_mutex_t LoggingLock::log_mutex = PTHREAD_MUTEX_INITIALIZER;
292#endif
293
294// Called by logging functions to ensure that debug_file is initialized
295// and can be used for writing. Returns false if the file could not be
296// initialized. debug_file will be NULL in this case.
297bool InitializeLogFileHandle() {
298  if (log_file)
299    return true;
300
301  if (!log_file_name) {
302    // Nobody has called InitLogging to specify a debug log file, so here we
303    // initialize the log file name to a default.
304    log_file_name = new PathString(GetDefaultLogFile());
305  }
306
307  if ((logging_destination & LOG_TO_FILE) != 0) {
308#if defined(OS_WIN)
309    log_file = CreateFile(log_file_name->c_str(), GENERIC_WRITE,
310                          FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
311                          OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
312    if (log_file == INVALID_HANDLE_VALUE || log_file == NULL) {
313      // try the current directory
314      log_file = CreateFile(L".\\debug.log", GENERIC_WRITE,
315                            FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
316                            OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
317      if (log_file == INVALID_HANDLE_VALUE || log_file == NULL) {
318        log_file = NULL;
319        return false;
320      }
321    }
322    SetFilePointer(log_file, 0, 0, FILE_END);
323#elif defined(OS_POSIX)
324    log_file = fopen(log_file_name->c_str(), "a");
325    if (log_file == NULL)
326      return false;
327#endif
328  }
329
330  return true;
331}
332
333void CloseFile(FileHandle log) {
334#if defined(OS_WIN)
335  CloseHandle(log);
336#else
337  fclose(log);
338#endif
339}
340
341void CloseLogFileUnlocked() {
342  if (!log_file)
343    return;
344
345  CloseFile(log_file);
346  log_file = NULL;
347}
348
349}  // namespace
350
351LoggingSettings::LoggingSettings()
352    : logging_dest(LOG_DEFAULT),
353      log_file(NULL),
354      lock_log(LOCK_LOG_FILE),
355      delete_old(APPEND_TO_OLD_LOG_FILE) {}
356
357bool BaseInitLoggingImpl(const LoggingSettings& settings) {
358#if defined(OS_NACL)
359  // Can log only to the system debug log.
360  CHECK_EQ(settings.logging_dest & ~LOG_TO_SYSTEM_DEBUG_LOG, 0);
361#endif
362  CommandLine* command_line = CommandLine::ForCurrentProcess();
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    // NOTE: If g_vlog_info has already been initialized, it might be in use
368    // by another thread. Don't delete the old VLogInfo, just create a second
369    // one. We keep track of both to avoid memory leak warnings.
370    CHECK(!g_vlog_info_prev);
371    g_vlog_info_prev = g_vlog_info;
372
373    g_vlog_info =
374        new VlogInfo(command_line->GetSwitchValueASCII(switches::kV),
375                     command_line->GetSwitchValueASCII(switches::kVModule),
376                     &min_log_level);
377  }
378
379  logging_destination = settings.logging_dest;
380
381  // ignore file options unless logging to file is set.
382  if ((logging_destination & LOG_TO_FILE) == 0)
383    return true;
384
385  LoggingLock::Init(settings.lock_log, settings.log_file);
386  LoggingLock logging_lock;
387
388  // Calling InitLogging twice or after some log call has already opened the
389  // default log file will re-initialize to the new options.
390  CloseLogFileUnlocked();
391
392  if (!log_file_name)
393    log_file_name = new PathString();
394  *log_file_name = settings.log_file;
395  if (settings.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_FATAL, 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  // Note: g_vlog_info may change on a different thread during startup
416  // (but will always be valid or NULL).
417  VlogInfo* vlog_info = g_vlog_info;
418  return vlog_info ?
419      vlog_info->GetVlogLevel(base::StringPiece(file, N - 1)) :
420      GetVlogVerbosity();
421}
422
423void SetLogItems(bool enable_process_id, bool enable_thread_id,
424                 bool enable_timestamp, bool enable_tickcount) {
425  log_process_id = enable_process_id;
426  log_thread_id = enable_thread_id;
427  log_timestamp = enable_timestamp;
428  log_tickcount = enable_tickcount;
429}
430
431void SetShowErrorDialogs(bool enable_dialogs) {
432  show_error_dialogs = enable_dialogs;
433}
434
435void SetLogAssertHandler(LogAssertHandlerFunction handler) {
436  log_assert_handler = handler;
437}
438
439void SetLogMessageHandler(LogMessageHandlerFunction handler) {
440  log_message_handler = handler;
441}
442
443LogMessageHandlerFunction GetLogMessageHandler() {
444  return log_message_handler;
445}
446
447// MSVC doesn't like complex extern templates and DLLs.
448#if !defined(COMPILER_MSVC)
449// Explicit instantiations for commonly used comparisons.
450template std::string* MakeCheckOpString<int, int>(
451    const int&, const int&, const char* names);
452template std::string* MakeCheckOpString<unsigned long, unsigned long>(
453    const unsigned long&, const unsigned long&, const char* names);
454template std::string* MakeCheckOpString<unsigned long, unsigned int>(
455    const unsigned long&, const unsigned int&, const char* names);
456template std::string* MakeCheckOpString<unsigned int, unsigned long>(
457    const unsigned int&, const unsigned long&, const char* names);
458template std::string* MakeCheckOpString<std::string, std::string>(
459    const std::string&, const std::string&, const char* name);
460#endif
461
462#if !defined(NDEBUG)
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 = base::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#endif  // !defined(NDEBUG)
514
515#if defined(OS_WIN)
516LogMessage::SaveLastError::SaveLastError() : last_error_(::GetLastError()) {
517}
518
519LogMessage::SaveLastError::~SaveLastError() {
520  ::SetLastError(last_error_);
521}
522#endif  // defined(OS_WIN)
523
524LogMessage::LogMessage(const char* file, int line, LogSeverity severity)
525    : severity_(severity), file_(file), line_(line) {
526  Init(file, line);
527}
528
529LogMessage::LogMessage(const char* file, int line, std::string* result)
530    : severity_(LOG_FATAL), file_(file), line_(line) {
531  Init(file, line);
532  stream_ << "Check failed: " << *result;
533  delete result;
534}
535
536LogMessage::LogMessage(const char* file, int line, LogSeverity severity,
537                       std::string* result)
538    : severity_(severity), file_(file), line_(line) {
539  Init(file, line);
540  stream_ << "Check failed: " << *result;
541  delete result;
542}
543
544LogMessage::~LogMessage() {
545#if !defined(NDEBUG) && !defined(OS_NACL) && !defined(__UCLIBC__)
546  if (severity_ == LOG_FATAL) {
547    // Include a stack trace on a fatal.
548    base::debug::StackTrace trace;
549    stream_ << std::endl;  // Newline to separate from log message.
550    trace.OutputToStream(&stream_);
551  }
552#endif
553  stream_ << std::endl;
554  std::string str_newline(stream_.str());
555
556  // Give any log message handler first dibs on the message.
557  if (log_message_handler &&
558      log_message_handler(severity_, file_, line_,
559                          message_start_, str_newline)) {
560    // The handler took care of it, no further processing.
561    return;
562  }
563
564  if ((logging_destination & LOG_TO_SYSTEM_DEBUG_LOG) != 0) {
565#if defined(OS_WIN)
566    OutputDebugStringA(str_newline.c_str());
567#elif defined(OS_ANDROID)
568    android_LogPriority priority =
569        (severity_ < 0) ? ANDROID_LOG_VERBOSE : ANDROID_LOG_UNKNOWN;
570    switch (severity_) {
571      case LOG_INFO:
572        priority = ANDROID_LOG_INFO;
573        break;
574      case LOG_WARNING:
575        priority = ANDROID_LOG_WARN;
576        break;
577      case LOG_ERROR:
578        priority = ANDROID_LOG_ERROR;
579        break;
580      case LOG_FATAL:
581        priority = ANDROID_LOG_FATAL;
582        break;
583    }
584    __android_log_write(priority, "chromium", str_newline.c_str());
585#endif
586    ignore_result(fwrite(str_newline.data(), str_newline.size(), 1, stderr));
587    fflush(stderr);
588  } else if (severity_ >= kAlwaysPrintErrorLevel) {
589    // When we're only outputting to a log file, above a certain log level, we
590    // should still output to stderr so that we can better detect and diagnose
591    // problems with unit tests, especially on the buildbots.
592    ignore_result(fwrite(str_newline.data(), str_newline.size(), 1, stderr));
593    fflush(stderr);
594  }
595
596  // write to log file
597  if ((logging_destination & LOG_TO_FILE) != 0) {
598    // We can have multiple threads and/or processes, so try to prevent them
599    // from clobbering each other's writes.
600    // If the client app did not call InitLogging, and the lock has not
601    // been created do it now. We do this on demand, but if two threads try
602    // to do this at the same time, there will be a race condition to create
603    // the lock. This is why InitLogging should be called from the main
604    // thread at the beginning of execution.
605    LoggingLock::Init(LOCK_LOG_FILE, NULL);
606    LoggingLock logging_lock;
607    if (InitializeLogFileHandle()) {
608#if defined(OS_WIN)
609      SetFilePointer(log_file, 0, 0, SEEK_END);
610      DWORD num_written;
611      WriteFile(log_file,
612                static_cast<const void*>(str_newline.c_str()),
613                static_cast<DWORD>(str_newline.length()),
614                &num_written,
615                NULL);
616#else
617      ignore_result(fwrite(
618          str_newline.data(), str_newline.size(), 1, log_file));
619      fflush(log_file);
620#endif
621    }
622  }
623
624  if (severity_ == LOG_FATAL) {
625    // Ensure the first characters of the string are on the stack so they
626    // are contained in minidumps for diagnostic purposes.
627    char str_stack[1024];
628    str_newline.copy(str_stack, arraysize(str_stack));
629    base::debug::Alias(str_stack);
630
631    if (log_assert_handler) {
632      // Make a copy of the string for the handler out of paranoia.
633      log_assert_handler(std::string(stream_.str()));
634    } else {
635      // Don't use the string with the newline, get a fresh version to send to
636      // the debug message process. We also don't display assertions to the
637      // user in release mode. The enduser can't do anything with this
638      // information, and displaying message boxes when the application is
639      // hosed can cause additional problems.
640#ifndef NDEBUG
641      DisplayDebugMessageInDialog(stream_.str());
642#endif
643      // Crash the process to generate a dump.
644      base::debug::BreakDebugger();
645    }
646  }
647}
648
649// writes the common header info to the stream
650void LogMessage::Init(const char* file, int line) {
651  base::StringPiece filename(file);
652  size_t last_slash_pos = filename.find_last_of("\\/");
653  if (last_slash_pos != base::StringPiece::npos)
654    filename.remove_prefix(last_slash_pos + 1);
655
656  // TODO(darin): It might be nice if the columns were fixed width.
657
658  stream_ <<  '[';
659  if (log_process_id)
660    stream_ << CurrentProcessId() << ':';
661  if (log_thread_id)
662    stream_ << base::PlatformThread::CurrentId() << ':';
663  if (log_timestamp) {
664    time_t t = time(NULL);
665    struct tm local_time = {0};
666#if _MSC_VER >= 1400
667    localtime_s(&local_time, &t);
668#else
669    localtime_r(&t, &local_time);
670#endif
671    struct tm* tm_time = &local_time;
672    stream_ << std::setfill('0')
673            << std::setw(2) << 1 + tm_time->tm_mon
674            << std::setw(2) << tm_time->tm_mday
675            << '/'
676            << std::setw(2) << tm_time->tm_hour
677            << std::setw(2) << tm_time->tm_min
678            << std::setw(2) << tm_time->tm_sec
679            << ':';
680  }
681  if (log_tickcount)
682    stream_ << TickCount() << ':';
683  if (severity_ >= 0)
684    stream_ << log_severity_name(severity_);
685  else
686    stream_ << "VERBOSE" << -severity_;
687
688  stream_ << ":" << filename << "(" << line << ")] ";
689
690  message_start_ = stream_.tellp();
691}
692
693#if defined(OS_WIN)
694// This has already been defined in the header, but defining it again as DWORD
695// ensures that the type used in the header is equivalent to DWORD. If not,
696// the redefinition is a compile error.
697typedef DWORD SystemErrorCode;
698#endif
699
700SystemErrorCode GetLastSystemErrorCode() {
701#if defined(OS_WIN)
702  return ::GetLastError();
703#elif defined(OS_POSIX)
704  return errno;
705#else
706#error Not implemented
707#endif
708}
709
710#if defined(OS_WIN)
711BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code) {
712  const int error_message_buffer_size = 256;
713  char msgbuf[error_message_buffer_size];
714  DWORD flags = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
715  DWORD len = FormatMessageA(flags, NULL, error_code, 0, msgbuf,
716                             arraysize(msgbuf), NULL);
717  if (len) {
718    // Messages returned by system end with line breaks.
719    return base::CollapseWhitespaceASCII(msgbuf, true) +
720        base::StringPrintf(" (0x%X)", error_code);
721  }
722  return base::StringPrintf("Error (0x%X) while retrieving error. (0x%X)",
723                            GetLastError(), error_code);
724}
725#elif defined(OS_POSIX)
726BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code) {
727  return safe_strerror(error_code);
728}
729#else
730#error Not implemented
731#endif
732
733
734#if defined(OS_WIN)
735Win32ErrorLogMessage::Win32ErrorLogMessage(const char* file,
736                                           int line,
737                                           LogSeverity severity,
738                                           SystemErrorCode err)
739    : err_(err),
740      log_message_(file, line, severity) {
741}
742
743Win32ErrorLogMessage::~Win32ErrorLogMessage() {
744  stream() << ": " << SystemErrorCodeToString(err_);
745  // We're about to crash (CHECK). Put |err_| on the stack (by placing it in a
746  // field) and use Alias in hopes that it makes it into crash dumps.
747  DWORD last_error = err_;
748  base::debug::Alias(&last_error);
749}
750#elif defined(OS_POSIX)
751ErrnoLogMessage::ErrnoLogMessage(const char* file,
752                                 int line,
753                                 LogSeverity severity,
754                                 SystemErrorCode err)
755    : err_(err),
756      log_message_(file, line, severity) {
757}
758
759ErrnoLogMessage::~ErrnoLogMessage() {
760  stream() << ": " << SystemErrorCodeToString(err_);
761}
762#endif  // OS_WIN
763
764void CloseLogFile() {
765  LoggingLock logging_lock;
766  CloseLogFileUnlocked();
767}
768
769void RawLog(int level, const char* message) {
770  if (level >= min_log_level) {
771    size_t bytes_written = 0;
772    const size_t message_len = strlen(message);
773    int rv;
774    while (bytes_written < message_len) {
775      rv = HANDLE_EINTR(
776          write(STDERR_FILENO, message + bytes_written,
777                message_len - bytes_written));
778      if (rv < 0) {
779        // Give up, nothing we can do now.
780        break;
781      }
782      bytes_written += rv;
783    }
784
785    if (message_len > 0 && message[message_len - 1] != '\n') {
786      do {
787        rv = HANDLE_EINTR(write(STDERR_FILENO, "\n", 1));
788        if (rv < 0) {
789          // Give up, nothing we can do now.
790          break;
791        }
792      } while (rv != 1);
793    }
794  }
795
796  if (level == LOG_FATAL)
797    base::debug::BreakDebugger();
798}
799
800// This was defined at the beginning of this file.
801#undef write
802
803#if defined(OS_WIN)
804std::wstring GetLogFileFullPath() {
805  if (log_file_name)
806    return *log_file_name;
807  return std::wstring();
808}
809#endif
810
811}  // namespace logging
812
813std::ostream& std::operator<<(std::ostream& out, const wchar_t* wstr) {
814  return out << base::WideToUTF8(std::wstring(wstr));
815}
816