michael@0: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #ifndef BASE_LOGGING_H_
michael@0: #define BASE_LOGGING_H_
michael@0: 
michael@0: #include <cassert>
michael@0: #include <string>
michael@0: #include <cstring>
michael@0: #include <sstream>
michael@0: 
michael@0: #include "base/base_export.h"
michael@0: #include "base/basictypes.h"
michael@0: #include "base/debug/debugger.h"
michael@0: #include "build/build_config.h"
michael@0: 
michael@0: //
michael@0: // Optional message capabilities
michael@0: // -----------------------------
michael@0: // Assertion failed messages and fatal errors are displayed in a dialog box
michael@0: // before the application exits. However, running this UI creates a message
michael@0: // loop, which causes application messages to be processed and potentially
michael@0: // dispatched to existing application windows. Since the application is in a
michael@0: // bad state when this assertion dialog is displayed, these messages may not
michael@0: // get processed and hang the dialog, or the application might go crazy.
michael@0: //
michael@0: // Therefore, it can be beneficial to display the error dialog in a separate
michael@0: // process from the main application. When the logging system needs to display
michael@0: // a fatal error dialog box, it will look for a program called
michael@0: // "DebugMessage.exe" in the same directory as the application executable. It
michael@0: // will run this application with the message as the command line, and will
michael@0: // not include the name of the application as is traditional for easier
michael@0: // parsing.
michael@0: //
michael@0: // The code for DebugMessage.exe is only one line. In WinMain, do:
michael@0: //   MessageBox(NULL, GetCommandLineW(), L"Fatal Error", 0);
michael@0: //
michael@0: // If DebugMessage.exe is not found, the logging code will use a normal
michael@0: // MessageBox, potentially causing the problems discussed above.
michael@0: 
michael@0: 
michael@0: // Instructions
michael@0: // ------------
michael@0: //
michael@0: // Make a bunch of macros for logging.  The way to log things is to stream
michael@0: // things to LOG(<a particular severity level>).  E.g.,
michael@0: //
michael@0: //   LOG(INFO) << "Found " << num_cookies << " cookies";
michael@0: //
michael@0: // You can also do conditional logging:
michael@0: //
michael@0: //   LOG_IF(INFO, num_cookies > 10) << "Got lots of cookies";
michael@0: //
michael@0: // The above will cause log messages to be output on the 1st, 11th, 21st, ...
michael@0: // times it is executed.  Note that the special COUNTER value is used to
michael@0: // identify which repetition is happening.
michael@0: //
michael@0: // The CHECK(condition) macro is active in both debug and release builds and
michael@0: // effectively performs a LOG(FATAL) which terminates the process and
michael@0: // generates a crashdump unless a debugger is attached.
michael@0: //
michael@0: // There are also "debug mode" logging macros like the ones above:
michael@0: //
michael@0: //   DLOG(INFO) << "Found cookies";
michael@0: //
michael@0: //   DLOG_IF(INFO, num_cookies > 10) << "Got lots of cookies";
michael@0: //
michael@0: // All "debug mode" logging is compiled away to nothing for non-debug mode
michael@0: // compiles.  LOG_IF and development flags also work well together
michael@0: // because the code can be compiled away sometimes.
michael@0: //
michael@0: // We also have
michael@0: //
michael@0: //   LOG_ASSERT(assertion);
michael@0: //   DLOG_ASSERT(assertion);
michael@0: //
michael@0: // which is syntactic sugar for {,D}LOG_IF(FATAL, assert fails) << assertion;
michael@0: //
michael@0: // There are "verbose level" logging macros.  They look like
michael@0: //
michael@0: //   VLOG(1) << "I'm printed when you run the program with --v=1 or more";
michael@0: //   VLOG(2) << "I'm printed when you run the program with --v=2 or more";
michael@0: //
michael@0: // These always log at the INFO log level (when they log at all).
michael@0: // The verbose logging can also be turned on module-by-module.  For instance,
michael@0: //    --vmodule=profile=2,icon_loader=1,browser_*=3,*/chromeos/*=4 --v=0
michael@0: // will cause:
michael@0: //   a. VLOG(2) and lower messages to be printed from profile.{h,cc}
michael@0: //   b. VLOG(1) and lower messages to be printed from icon_loader.{h,cc}
michael@0: //   c. VLOG(3) and lower messages to be printed from files prefixed with
michael@0: //      "browser"
michael@0: //   d. VLOG(4) and lower messages to be printed from files under a
michael@0: //     "chromeos" directory.
michael@0: //   e. VLOG(0) and lower messages to be printed from elsewhere
michael@0: //
michael@0: // The wildcarding functionality shown by (c) supports both '*' (match
michael@0: // 0 or more characters) and '?' (match any single character)
michael@0: // wildcards.  Any pattern containing a forward or backward slash will
michael@0: // be tested against the whole pathname and not just the module.
michael@0: // E.g., "*/foo/bar/*=2" would change the logging level for all code
michael@0: // in source files under a "foo/bar" directory.
michael@0: //
michael@0: // There's also VLOG_IS_ON(n) "verbose level" condition macro. To be used as
michael@0: //
michael@0: //   if (VLOG_IS_ON(2)) {
michael@0: //     // do some logging preparation and logging
michael@0: //     // that can't be accomplished with just VLOG(2) << ...;
michael@0: //   }
michael@0: //
michael@0: // There is also a VLOG_IF "verbose level" condition macro for sample
michael@0: // cases, when some extra computation and preparation for logs is not
michael@0: // needed.
michael@0: //
michael@0: //   VLOG_IF(1, (size > 1024))
michael@0: //      << "I'm printed when size is more than 1024 and when you run the "
michael@0: //         "program with --v=1 or more";
michael@0: //
michael@0: // We also override the standard 'assert' to use 'DLOG_ASSERT'.
michael@0: //
michael@0: // Lastly, there is:
michael@0: //
michael@0: //   PLOG(ERROR) << "Couldn't do foo";
michael@0: //   DPLOG(ERROR) << "Couldn't do foo";
michael@0: //   PLOG_IF(ERROR, cond) << "Couldn't do foo";
michael@0: //   DPLOG_IF(ERROR, cond) << "Couldn't do foo";
michael@0: //   PCHECK(condition) << "Couldn't do foo";
michael@0: //   DPCHECK(condition) << "Couldn't do foo";
michael@0: //
michael@0: // which append the last system error to the message in string form (taken from
michael@0: // GetLastError() on Windows and errno on POSIX).
michael@0: //
michael@0: // The supported severity levels for macros that allow you to specify one
michael@0: // are (in increasing order of severity) INFO, WARNING, ERROR, ERROR_REPORT,
michael@0: // and FATAL.
michael@0: //
michael@0: // Very important: logging a message at the FATAL severity level causes
michael@0: // the program to terminate (after the message is logged).
michael@0: //
michael@0: // Note the special severity of ERROR_REPORT only available/relevant in normal
michael@0: // mode, which displays error dialog without terminating the program. There is
michael@0: // no error dialog for severity ERROR or below in normal mode.
michael@0: //
michael@0: // There is also the special severity of DFATAL, which logs FATAL in
michael@0: // debug mode, ERROR in normal mode.
michael@0: 
michael@0: namespace logging {
michael@0: 
michael@0: // TODO(avi): do we want to do a unification of character types here?
michael@0: #if defined(OS_WIN)
michael@0: typedef wchar_t PathChar;
michael@0: #else
michael@0: typedef char PathChar;
michael@0: #endif
michael@0: 
michael@0: // Where to record logging output? A flat file and/or system debug log
michael@0: // via OutputDebugString.
michael@0: enum LoggingDestination {
michael@0:   LOG_NONE                = 0,
michael@0:   LOG_TO_FILE             = 1 << 0,
michael@0:   LOG_TO_SYSTEM_DEBUG_LOG = 1 << 1,
michael@0: 
michael@0:   LOG_TO_ALL = LOG_TO_FILE | LOG_TO_SYSTEM_DEBUG_LOG,
michael@0: 
michael@0:   // On Windows, use a file next to the exe; on POSIX platforms, where
michael@0:   // it may not even be possible to locate the executable on disk, use
michael@0:   // stderr.
michael@0: #if defined(OS_WIN)
michael@0:   LOG_DEFAULT = LOG_TO_FILE,
michael@0: #elif defined(OS_POSIX)
michael@0:   LOG_DEFAULT = LOG_TO_SYSTEM_DEBUG_LOG,
michael@0: #endif
michael@0: };
michael@0: 
michael@0: // Indicates that the log file should be locked when being written to.
michael@0: // Unless there is only one single-threaded process that is logging to
michael@0: // the log file, the file should be locked during writes to make each
michael@0: // log outut atomic. Other writers will block.
michael@0: //
michael@0: // All processes writing to the log file must have their locking set for it to
michael@0: // work properly. Defaults to LOCK_LOG_FILE.
michael@0: enum LogLockingState { LOCK_LOG_FILE, DONT_LOCK_LOG_FILE };
michael@0: 
michael@0: // On startup, should we delete or append to an existing log file (if any)?
michael@0: // Defaults to APPEND_TO_OLD_LOG_FILE.
michael@0: enum OldFileDeletionState { DELETE_OLD_LOG_FILE, APPEND_TO_OLD_LOG_FILE };
michael@0: 
michael@0: enum DcheckState {
michael@0:   DISABLE_DCHECK_FOR_NON_OFFICIAL_RELEASE_BUILDS,
michael@0:   ENABLE_DCHECK_FOR_NON_OFFICIAL_RELEASE_BUILDS
michael@0: };
michael@0: 
michael@0: struct BASE_EXPORT LoggingSettings {
michael@0:   // The defaults values are:
michael@0:   //
michael@0:   //  logging_dest: LOG_DEFAULT
michael@0:   //  log_file:     NULL
michael@0:   //  lock_log:     LOCK_LOG_FILE
michael@0:   //  delete_old:   APPEND_TO_OLD_LOG_FILE
michael@0:   //  dcheck_state: DISABLE_DCHECK_FOR_NON_OFFICIAL_RELEASE_BUILDS
michael@0:   LoggingSettings();
michael@0: 
michael@0:   LoggingDestination logging_dest;
michael@0: 
michael@0:   // The three settings below have an effect only when LOG_TO_FILE is
michael@0:   // set in |logging_dest|.
michael@0:   const PathChar* log_file;
michael@0:   LogLockingState lock_log;
michael@0:   OldFileDeletionState delete_old;
michael@0: 
michael@0:   DcheckState dcheck_state;
michael@0: };
michael@0: 
michael@0: // Define different names for the BaseInitLoggingImpl() function depending on
michael@0: // whether NDEBUG is defined or not so that we'll fail to link if someone tries
michael@0: // to compile logging.cc with NDEBUG but includes logging.h without defining it,
michael@0: // or vice versa.
michael@0: #if NDEBUG
michael@0: #define BaseInitLoggingImpl BaseInitLoggingImpl_built_with_NDEBUG
michael@0: #else
michael@0: #define BaseInitLoggingImpl BaseInitLoggingImpl_built_without_NDEBUG
michael@0: #endif
michael@0: 
michael@0: // Implementation of the InitLogging() method declared below.  We use a
michael@0: // more-specific name so we can #define it above without affecting other code
michael@0: // that has named stuff "InitLogging".
michael@0: BASE_EXPORT bool BaseInitLoggingImpl(const LoggingSettings& settings);
michael@0: 
michael@0: // Sets the log file name and other global logging state. Calling this function
michael@0: // is recommended, and is normally done at the beginning of application init.
michael@0: // If you don't call it, all the flags will be initialized to their default
michael@0: // values, and there is a race condition that may leak a critical section
michael@0: // object if two threads try to do the first log at the same time.
michael@0: // See the definition of the enums above for descriptions and default values.
michael@0: //
michael@0: // The default log file is initialized to "debug.log" in the application
michael@0: // directory. You probably don't want this, especially since the program
michael@0: // directory may not be writable on an enduser's system.
michael@0: //
michael@0: // This function may be called a second time to re-direct logging (e.g after
michael@0: // loging in to a user partition), however it should never be called more than
michael@0: // twice.
michael@0: inline bool InitLogging(const LoggingSettings& settings) {
michael@0:   return BaseInitLoggingImpl(settings);
michael@0: }
michael@0: 
michael@0: // Sets the log level. Anything at or above this level will be written to the
michael@0: // log file/displayed to the user (if applicable). Anything below this level
michael@0: // will be silently ignored. The log level defaults to 0 (everything is logged
michael@0: // up to level INFO) if this function is not called.
michael@0: // Note that log messages for VLOG(x) are logged at level -x, so setting
michael@0: // the min log level to negative values enables verbose logging.
michael@0: BASE_EXPORT void SetMinLogLevel(int level);
michael@0: 
michael@0: // Gets the current log level.
michael@0: BASE_EXPORT int GetMinLogLevel();
michael@0: 
michael@0: // Gets the VLOG default verbosity level.
michael@0: BASE_EXPORT int GetVlogVerbosity();
michael@0: 
michael@0: // Gets the current vlog level for the given file (usually taken from
michael@0: // __FILE__).
michael@0: 
michael@0: // Note that |N| is the size *with* the null terminator.
michael@0: BASE_EXPORT int GetVlogLevelHelper(const char* file_start, size_t N);
michael@0: 
michael@0: template <size_t N>
michael@0: int GetVlogLevel(const char (&file)[N]) {
michael@0:   return GetVlogLevelHelper(file, N);
michael@0: }
michael@0: 
michael@0: // Sets the common items you want to be prepended to each log message.
michael@0: // process and thread IDs default to off, the timestamp defaults to on.
michael@0: // If this function is not called, logging defaults to writing the timestamp
michael@0: // only.
michael@0: BASE_EXPORT void SetLogItems(bool enable_process_id, bool enable_thread_id,
michael@0:                              bool enable_timestamp, bool enable_tickcount);
michael@0: 
michael@0: // Sets whether or not you'd like to see fatal debug messages popped up in
michael@0: // a dialog box or not.
michael@0: // Dialogs are not shown by default.
michael@0: BASE_EXPORT void SetShowErrorDialogs(bool enable_dialogs);
michael@0: 
michael@0: // Sets the Log Assert Handler that will be used to notify of check failures.
michael@0: // The default handler shows a dialog box and then terminate the process,
michael@0: // however clients can use this function to override with their own handling
michael@0: // (e.g. a silent one for Unit Tests)
michael@0: typedef void (*LogAssertHandlerFunction)(const std::string& str);
michael@0: BASE_EXPORT void SetLogAssertHandler(LogAssertHandlerFunction handler);
michael@0: 
michael@0: // Sets the Log Report Handler that will be used to notify of check failures
michael@0: // in non-debug mode. The default handler shows a dialog box and continues
michael@0: // the execution, however clients can use this function to override with their
michael@0: // own handling.
michael@0: typedef void (*LogReportHandlerFunction)(const std::string& str);
michael@0: BASE_EXPORT void SetLogReportHandler(LogReportHandlerFunction handler);
michael@0: 
michael@0: // Sets the Log Message Handler that gets passed every log message before
michael@0: // it's sent to other log destinations (if any).
michael@0: // Returns true to signal that it handled the message and the message
michael@0: // should not be sent to other log destinations.
michael@0: typedef bool (*LogMessageHandlerFunction)(int severity,
michael@0:     const char* file, int line, size_t message_start, const std::string& str);
michael@0: BASE_EXPORT void SetLogMessageHandler(LogMessageHandlerFunction handler);
michael@0: BASE_EXPORT LogMessageHandlerFunction GetLogMessageHandler();
michael@0: 
michael@0: typedef int LogSeverity;
michael@0: const LogSeverity LOG_VERBOSE = -1;  // This is level 1 verbosity
michael@0: // Note: the log severities are used to index into the array of names,
michael@0: // see log_severity_names.
michael@0: const LogSeverity LOG_INFO = 0;
michael@0: const LogSeverity LOG_WARNING = 1;
michael@0: const LogSeverity LOG_ERROR = 2;
michael@0: const LogSeverity LOG_ERROR_REPORT = 3;
michael@0: const LogSeverity LOG_FATAL = 4;
michael@0: const LogSeverity LOG_NUM_SEVERITIES = 5;
michael@0: 
michael@0: // LOG_DFATAL is LOG_FATAL in debug mode, ERROR in normal mode
michael@0: #ifdef NDEBUG
michael@0: const LogSeverity LOG_DFATAL = LOG_ERROR;
michael@0: #else
michael@0: const LogSeverity LOG_DFATAL = LOG_FATAL;
michael@0: #endif
michael@0: 
michael@0: // A few definitions of macros that don't generate much code. These are used
michael@0: // by LOG() and LOG_IF, etc. Since these are used all over our code, it's
michael@0: // better to have compact code for these operations.
michael@0: #define COMPACT_GOOGLE_LOG_EX_INFO(ClassName, ...) \
michael@0:   logging::ClassName(__FILE__, __LINE__, logging::LOG_INFO , ##__VA_ARGS__)
michael@0: #define COMPACT_GOOGLE_LOG_EX_WARNING(ClassName, ...) \
michael@0:   logging::ClassName(__FILE__, __LINE__, logging::LOG_WARNING , ##__VA_ARGS__)
michael@0: #define COMPACT_GOOGLE_LOG_EX_ERROR(ClassName, ...) \
michael@0:   logging::ClassName(__FILE__, __LINE__, logging::LOG_ERROR , ##__VA_ARGS__)
michael@0: #define COMPACT_GOOGLE_LOG_EX_ERROR_REPORT(ClassName, ...) \
michael@0:   logging::ClassName(__FILE__, __LINE__, \
michael@0:                      logging::LOG_ERROR_REPORT , ##__VA_ARGS__)
michael@0: #define COMPACT_GOOGLE_LOG_EX_FATAL(ClassName, ...) \
michael@0:   logging::ClassName(__FILE__, __LINE__, logging::LOG_FATAL , ##__VA_ARGS__)
michael@0: #define COMPACT_GOOGLE_LOG_EX_DFATAL(ClassName, ...) \
michael@0:   logging::ClassName(__FILE__, __LINE__, logging::LOG_DFATAL , ##__VA_ARGS__)
michael@0: 
michael@0: #define COMPACT_GOOGLE_LOG_INFO \
michael@0:   COMPACT_GOOGLE_LOG_EX_INFO(LogMessage)
michael@0: #define COMPACT_GOOGLE_LOG_WARNING \
michael@0:   COMPACT_GOOGLE_LOG_EX_WARNING(LogMessage)
michael@0: #define COMPACT_GOOGLE_LOG_ERROR \
michael@0:   COMPACT_GOOGLE_LOG_EX_ERROR(LogMessage)
michael@0: #define COMPACT_GOOGLE_LOG_ERROR_REPORT \
michael@0:   COMPACT_GOOGLE_LOG_EX_ERROR_REPORT(LogMessage)
michael@0: #define COMPACT_GOOGLE_LOG_FATAL \
michael@0:   COMPACT_GOOGLE_LOG_EX_FATAL(LogMessage)
michael@0: #define COMPACT_GOOGLE_LOG_DFATAL \
michael@0:   COMPACT_GOOGLE_LOG_EX_DFATAL(LogMessage)
michael@0: 
michael@0: #if defined(OS_WIN)
michael@0: // wingdi.h defines ERROR to be 0. When we call LOG(ERROR), it gets
michael@0: // substituted with 0, and it expands to COMPACT_GOOGLE_LOG_0. To allow us
michael@0: // to keep using this syntax, we define this macro to do the same thing
michael@0: // as COMPACT_GOOGLE_LOG_ERROR, and also define ERROR the same way that
michael@0: // the Windows SDK does for consistency.
michael@0: #define ERROR 0
michael@0: #define COMPACT_GOOGLE_LOG_EX_0(ClassName, ...) \
michael@0:   COMPACT_GOOGLE_LOG_EX_ERROR(ClassName , ##__VA_ARGS__)
michael@0: #define COMPACT_GOOGLE_LOG_0 COMPACT_GOOGLE_LOG_ERROR
michael@0: // Needed for LOG_IS_ON(ERROR).
michael@0: const LogSeverity LOG_0 = LOG_ERROR;
michael@0: #endif
michael@0: 
michael@0: // As special cases, we can assume that LOG_IS_ON(ERROR_REPORT) and
michael@0: // LOG_IS_ON(FATAL) always hold.  Also, LOG_IS_ON(DFATAL) always holds
michael@0: // in debug mode.  In particular, CHECK()s will always fire if they
michael@0: // fail.
michael@0: #define LOG_IS_ON(severity) \
michael@0:   ((::logging::LOG_ ## severity) >= ::logging::GetMinLogLevel())
michael@0: 
michael@0: // We can't do any caching tricks with VLOG_IS_ON() like the
michael@0: // google-glog version since it requires GCC extensions.  This means
michael@0: // that using the v-logging functions in conjunction with --vmodule
michael@0: // may be slow.
michael@0: #define VLOG_IS_ON(verboselevel) \
michael@0:   ((verboselevel) <= ::logging::GetVlogLevel(__FILE__))
michael@0: 
michael@0: // Helper macro which avoids evaluating the arguments to a stream if
michael@0: // the condition doesn't hold.
michael@0: #define LAZY_STREAM(stream, condition)                                  \
michael@0:   !(condition) ? (void) 0 : ::logging::LogMessageVoidify() & (stream)
michael@0: 
michael@0: // We use the preprocessor's merging operator, "##", so that, e.g.,
michael@0: // LOG(INFO) becomes the token COMPACT_GOOGLE_LOG_INFO.  There's some funny
michael@0: // subtle difference between ostream member streaming functions (e.g.,
michael@0: // ostream::operator<<(int) and ostream non-member streaming functions
michael@0: // (e.g., ::operator<<(ostream&, string&): it turns out that it's
michael@0: // impossible to stream something like a string directly to an unnamed
michael@0: // ostream. We employ a neat hack by calling the stream() member
michael@0: // function of LogMessage which seems to avoid the problem.
michael@0: #define LOG_STREAM(severity) COMPACT_GOOGLE_LOG_ ## severity.stream()
michael@0: 
michael@0: #define LOG(severity) LAZY_STREAM(LOG_STREAM(severity), LOG_IS_ON(severity))
michael@0: #define LOG_IF(severity, condition) \
michael@0:   LAZY_STREAM(LOG_STREAM(severity), LOG_IS_ON(severity) && (condition))
michael@0: 
michael@0: #define SYSLOG(severity) LOG(severity)
michael@0: #define SYSLOG_IF(severity, condition) LOG_IF(severity, condition)
michael@0: 
michael@0: // The VLOG macros log with negative verbosities.
michael@0: #define VLOG_STREAM(verbose_level) \
michael@0:   logging::LogMessage(__FILE__, __LINE__, -verbose_level).stream()
michael@0: 
michael@0: #define VLOG(verbose_level) \
michael@0:   LAZY_STREAM(VLOG_STREAM(verbose_level), VLOG_IS_ON(verbose_level))
michael@0: 
michael@0: #define VLOG_IF(verbose_level, condition) \
michael@0:   LAZY_STREAM(VLOG_STREAM(verbose_level), \
michael@0:       VLOG_IS_ON(verbose_level) && (condition))
michael@0: 
michael@0: #if defined (OS_WIN)
michael@0: #define VPLOG_STREAM(verbose_level) \
michael@0:   logging::Win32ErrorLogMessage(__FILE__, __LINE__, -verbose_level, \
michael@0:     ::logging::GetLastSystemErrorCode()).stream()
michael@0: #elif defined(OS_POSIX)
michael@0: #define VPLOG_STREAM(verbose_level) \
michael@0:   logging::ErrnoLogMessage(__FILE__, __LINE__, -verbose_level, \
michael@0:     ::logging::GetLastSystemErrorCode()).stream()
michael@0: #endif
michael@0: 
michael@0: #define VPLOG(verbose_level) \
michael@0:   LAZY_STREAM(VPLOG_STREAM(verbose_level), VLOG_IS_ON(verbose_level))
michael@0: 
michael@0: #define VPLOG_IF(verbose_level, condition) \
michael@0:   LAZY_STREAM(VPLOG_STREAM(verbose_level), \
michael@0:     VLOG_IS_ON(verbose_level) && (condition))
michael@0: 
michael@0: // TODO(akalin): Add more VLOG variants, e.g. VPLOG.
michael@0: 
michael@0: #define LOG_ASSERT(condition)  \
michael@0:   LOG_IF(FATAL, !(condition)) << "Assert failed: " #condition ". "
michael@0: #define SYSLOG_ASSERT(condition) \
michael@0:   SYSLOG_IF(FATAL, !(condition)) << "Assert failed: " #condition ". "
michael@0: 
michael@0: #if defined(OS_WIN)
michael@0: #define LOG_GETLASTERROR_STREAM(severity) \
michael@0:   COMPACT_GOOGLE_LOG_EX_ ## severity(Win32ErrorLogMessage, \
michael@0:       ::logging::GetLastSystemErrorCode()).stream()
michael@0: #define LOG_GETLASTERROR(severity) \
michael@0:   LAZY_STREAM(LOG_GETLASTERROR_STREAM(severity), LOG_IS_ON(severity))
michael@0: #define LOG_GETLASTERROR_MODULE_STREAM(severity, module) \
michael@0:   COMPACT_GOOGLE_LOG_EX_ ## severity(Win32ErrorLogMessage, \
michael@0:       ::logging::GetLastSystemErrorCode(), module).stream()
michael@0: #define LOG_GETLASTERROR_MODULE(severity, module)                       \
michael@0:   LAZY_STREAM(LOG_GETLASTERROR_STREAM(severity, module),                \
michael@0:               LOG_IS_ON(severity))
michael@0: // PLOG_STREAM is used by PLOG, which is the usual error logging macro
michael@0: // for each platform.
michael@0: #define PLOG_STREAM(severity) LOG_GETLASTERROR_STREAM(severity)
michael@0: #elif defined(OS_POSIX)
michael@0: #define LOG_ERRNO_STREAM(severity) \
michael@0:   COMPACT_GOOGLE_LOG_EX_ ## severity(ErrnoLogMessage, \
michael@0:       ::logging::GetLastSystemErrorCode()).stream()
michael@0: #define LOG_ERRNO(severity) \
michael@0:   LAZY_STREAM(LOG_ERRNO_STREAM(severity), LOG_IS_ON(severity))
michael@0: // PLOG_STREAM is used by PLOG, which is the usual error logging macro
michael@0: // for each platform.
michael@0: #define PLOG_STREAM(severity) LOG_ERRNO_STREAM(severity)
michael@0: #endif
michael@0: 
michael@0: #define PLOG(severity)                                          \
michael@0:   LAZY_STREAM(PLOG_STREAM(severity), LOG_IS_ON(severity))
michael@0: 
michael@0: #define PLOG_IF(severity, condition) \
michael@0:   LAZY_STREAM(PLOG_STREAM(severity), LOG_IS_ON(severity) && (condition))
michael@0: 
michael@0: #if !defined(NDEBUG)
michael@0: // Debug builds always include DCHECK and DLOG.
michael@0: #undef LOGGING_IS_OFFICIAL_BUILD
michael@0: #define LOGGING_IS_OFFICIAL_BUILD 0
michael@0: #elif defined(OFFICIAL_BUILD)
michael@0: // Official release builds always disable and remove DCHECK and DLOG.
michael@0: #undef LOGGING_IS_OFFICIAL_BUILD
michael@0: #define LOGGING_IS_OFFICIAL_BUILD 1
michael@0: #elif !defined(LOGGING_IS_OFFICIAL_BUILD)
michael@0: // Unless otherwise specified, unofficial release builds include
michael@0: // DCHECK and DLOG.
michael@0: #define LOGGING_IS_OFFICIAL_BUILD 0
michael@0: #endif
michael@0: 
michael@0: // The actual stream used isn't important.
michael@0: #define EAT_STREAM_PARAMETERS                                           \
michael@0:   true ? (void) 0 : ::logging::LogMessageVoidify() & LOG_STREAM(FATAL)
michael@0: 
michael@0: // CHECK dies with a fatal error if condition is not true.  It is *not*
michael@0: // controlled by NDEBUG, so the check will be executed regardless of
michael@0: // compilation mode.
michael@0: //
michael@0: // We make sure CHECK et al. always evaluates their arguments, as
michael@0: // doing CHECK(FunctionWithSideEffect()) is a common idiom.
michael@0: 
michael@0: #if LOGGING_IS_OFFICIAL_BUILD
michael@0: 
michael@0: // Make all CHECK functions discard their log strings to reduce code
michael@0: // bloat for official builds.
michael@0: 
michael@0: // TODO(akalin): This would be more valuable if there were some way to
michael@0: // remove BreakDebugger() from the backtrace, perhaps by turning it
michael@0: // into a macro (like __debugbreak() on Windows).
michael@0: #define CHECK(condition)                                                \
michael@0:   !(condition) ? ::base::debug::BreakDebugger() : EAT_STREAM_PARAMETERS
michael@0: 
michael@0: #define PCHECK(condition) CHECK(condition)
michael@0: 
michael@0: #define CHECK_OP(name, op, val1, val2) CHECK((val1) op (val2))
michael@0: 
michael@0: #else
michael@0: 
michael@0: #define CHECK(condition)                       \
michael@0:   LAZY_STREAM(LOG_STREAM(FATAL), !(condition)) \
michael@0:   << "Check failed: " #condition ". "
michael@0: 
michael@0: #define PCHECK(condition) \
michael@0:   LAZY_STREAM(PLOG_STREAM(FATAL), !(condition)) \
michael@0:   << "Check failed: " #condition ". "
michael@0: 
michael@0: // Helper macro for binary operators.
michael@0: // Don't use this macro directly in your code, use CHECK_EQ et al below.
michael@0: //
michael@0: // TODO(akalin): Rewrite this so that constructs like if (...)
michael@0: // CHECK_EQ(...) else { ... } work properly.
michael@0: #define CHECK_OP(name, op, val1, val2)                          \
michael@0:   if (std::string* _result =                                    \
michael@0:       logging::Check##name##Impl((val1), (val2),                \
michael@0:                                  #val1 " " #op " " #val2))      \
michael@0:     logging::LogMessage(__FILE__, __LINE__, _result).stream()
michael@0: 
michael@0: #endif
michael@0: 
michael@0: // Build the error message string.  This is separate from the "Impl"
michael@0: // function template because it is not performance critical and so can
michael@0: // be out of line, while the "Impl" code should be inline.  Caller
michael@0: // takes ownership of the returned string.
michael@0: template<class t1, class t2>
michael@0: std::string* MakeCheckOpString(const t1& v1, const t2& v2, const char* names) {
michael@0:   std::ostringstream ss;
michael@0:   ss << names << " (" << v1 << " vs. " << v2 << ")";
michael@0:   std::string* msg = new std::string(ss.str());
michael@0:   return msg;
michael@0: }
michael@0: 
michael@0: // MSVC doesn't like complex extern templates and DLLs.
michael@0: #if !defined(COMPILER_MSVC)
michael@0: // Commonly used instantiations of MakeCheckOpString<>. Explicitly instantiated
michael@0: // in logging.cc.
michael@0: extern template BASE_EXPORT std::string* MakeCheckOpString<int, int>(
michael@0:     const int&, const int&, const char* names);
michael@0: extern template BASE_EXPORT
michael@0: std::string* MakeCheckOpString<unsigned long, unsigned long>(
michael@0:     const unsigned long&, const unsigned long&, const char* names);
michael@0: extern template BASE_EXPORT
michael@0: std::string* MakeCheckOpString<unsigned long, unsigned int>(
michael@0:     const unsigned long&, const unsigned int&, const char* names);
michael@0: extern template BASE_EXPORT
michael@0: std::string* MakeCheckOpString<unsigned int, unsigned long>(
michael@0:     const unsigned int&, const unsigned long&, const char* names);
michael@0: extern template BASE_EXPORT
michael@0: std::string* MakeCheckOpString<std::string, std::string>(
michael@0:     const std::string&, const std::string&, const char* name);
michael@0: #endif
michael@0: 
michael@0: // Helper functions for CHECK_OP macro.
michael@0: // The (int, int) specialization works around the issue that the compiler
michael@0: // will not instantiate the template version of the function on values of
michael@0: // unnamed enum type - see comment below.
michael@0: #define DEFINE_CHECK_OP_IMPL(name, op) \
michael@0:   template <class t1, class t2> \
michael@0:   inline std::string* Check##name##Impl(const t1& v1, const t2& v2, \
michael@0:                                         const char* names) { \
michael@0:     if (v1 op v2) return NULL; \
michael@0:     else return MakeCheckOpString(v1, v2, names); \
michael@0:   } \
michael@0:   inline std::string* Check##name##Impl(int v1, int v2, const char* names) { \
michael@0:     if (v1 op v2) return NULL; \
michael@0:     else return MakeCheckOpString(v1, v2, names); \
michael@0:   }
michael@0: DEFINE_CHECK_OP_IMPL(EQ, ==)
michael@0: DEFINE_CHECK_OP_IMPL(NE, !=)
michael@0: DEFINE_CHECK_OP_IMPL(LE, <=)
michael@0: DEFINE_CHECK_OP_IMPL(LT, < )
michael@0: DEFINE_CHECK_OP_IMPL(GE, >=)
michael@0: DEFINE_CHECK_OP_IMPL(GT, > )
michael@0: #undef DEFINE_CHECK_OP_IMPL
michael@0: 
michael@0: #define CHECK_EQ(val1, val2) CHECK_OP(EQ, ==, val1, val2)
michael@0: #define CHECK_NE(val1, val2) CHECK_OP(NE, !=, val1, val2)
michael@0: #define CHECK_LE(val1, val2) CHECK_OP(LE, <=, val1, val2)
michael@0: #define CHECK_LT(val1, val2) CHECK_OP(LT, < , val1, val2)
michael@0: #define CHECK_GE(val1, val2) CHECK_OP(GE, >=, val1, val2)
michael@0: #define CHECK_GT(val1, val2) CHECK_OP(GT, > , val1, val2)
michael@0: 
michael@0: #if LOGGING_IS_OFFICIAL_BUILD
michael@0: // In order to have optimized code for official builds, remove DLOGs and
michael@0: // DCHECKs.
michael@0: #define ENABLE_DLOG 0
michael@0: #define ENABLE_DCHECK 0
michael@0: 
michael@0: #elif defined(NDEBUG)
michael@0: // Otherwise, if we're a release build, remove DLOGs but not DCHECKs
michael@0: // (since those can still be turned on via a command-line flag).
michael@0: #define ENABLE_DLOG 0
michael@0: #define ENABLE_DCHECK 1
michael@0: 
michael@0: #else
michael@0: // Otherwise, we're a debug build so enable DLOGs and DCHECKs.
michael@0: #define ENABLE_DLOG 1
michael@0: #define ENABLE_DCHECK 1
michael@0: #endif
michael@0: 
michael@0: // Definitions for DLOG et al.
michael@0: 
michael@0: #if ENABLE_DLOG
michael@0: 
michael@0: #define DLOG_IS_ON(severity) LOG_IS_ON(severity)
michael@0: #define DLOG_IF(severity, condition) LOG_IF(severity, condition)
michael@0: #define DLOG_ASSERT(condition) LOG_ASSERT(condition)
michael@0: #define DPLOG_IF(severity, condition) PLOG_IF(severity, condition)
michael@0: #define DVLOG_IF(verboselevel, condition) VLOG_IF(verboselevel, condition)
michael@0: #define DVPLOG_IF(verboselevel, condition) VPLOG_IF(verboselevel, condition)
michael@0: 
michael@0: #else  // ENABLE_DLOG
michael@0: 
michael@0: // If ENABLE_DLOG is off, we want to avoid emitting any references to
michael@0: // |condition| (which may reference a variable defined only if NDEBUG
michael@0: // is not defined).  Contrast this with DCHECK et al., which has
michael@0: // different behavior.
michael@0: 
michael@0: #define DLOG_IS_ON(severity) false
michael@0: #define DLOG_IF(severity, condition) EAT_STREAM_PARAMETERS
michael@0: #define DLOG_ASSERT(condition) EAT_STREAM_PARAMETERS
michael@0: #define DPLOG_IF(severity, condition) EAT_STREAM_PARAMETERS
michael@0: #define DVLOG_IF(verboselevel, condition) EAT_STREAM_PARAMETERS
michael@0: #define DVPLOG_IF(verboselevel, condition) EAT_STREAM_PARAMETERS
michael@0: 
michael@0: #endif  // ENABLE_DLOG
michael@0: 
michael@0: // DEBUG_MODE is for uses like
michael@0: //   if (DEBUG_MODE) foo.CheckThatFoo();
michael@0: // instead of
michael@0: //   #ifndef NDEBUG
michael@0: //     foo.CheckThatFoo();
michael@0: //   #endif
michael@0: //
michael@0: // We tie its state to ENABLE_DLOG.
michael@0: enum { DEBUG_MODE = ENABLE_DLOG };
michael@0: 
michael@0: #undef ENABLE_DLOG
michael@0: 
michael@0: #define DLOG(severity)                                          \
michael@0:   LAZY_STREAM(LOG_STREAM(severity), DLOG_IS_ON(severity))
michael@0: 
michael@0: #if defined(OS_WIN)
michael@0: #define DLOG_GETLASTERROR(severity) \
michael@0:   LAZY_STREAM(LOG_GETLASTERROR_STREAM(severity), DLOG_IS_ON(severity))
michael@0: #define DLOG_GETLASTERROR_MODULE(severity, module)                      \
michael@0:   LAZY_STREAM(LOG_GETLASTERROR_STREAM(severity, module),                \
michael@0:               DLOG_IS_ON(severity))
michael@0: #elif defined(OS_POSIX)
michael@0: #define DLOG_ERRNO(severity)                                    \
michael@0:   LAZY_STREAM(LOG_ERRNO_STREAM(severity), DLOG_IS_ON(severity))
michael@0: #endif
michael@0: 
michael@0: #define DPLOG(severity)                                         \
michael@0:   LAZY_STREAM(PLOG_STREAM(severity), DLOG_IS_ON(severity))
michael@0: 
michael@0: #define DVLOG(verboselevel) DVLOG_IF(verboselevel, VLOG_IS_ON(verboselevel))
michael@0: 
michael@0: #define DVPLOG(verboselevel) DVPLOG_IF(verboselevel, VLOG_IS_ON(verboselevel))
michael@0: 
michael@0: // Definitions for DCHECK et al.
michael@0: 
michael@0: #if ENABLE_DCHECK
michael@0: 
michael@0: #if defined(NDEBUG)
michael@0: 
michael@0: BASE_EXPORT DcheckState get_dcheck_state();
michael@0: BASE_EXPORT void set_dcheck_state(DcheckState state);
michael@0: 
michael@0: #if defined(DCHECK_ALWAYS_ON)
michael@0: 
michael@0: #define DCHECK_IS_ON() true
michael@0: #define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \
michael@0:   COMPACT_GOOGLE_LOG_EX_FATAL(ClassName , ##__VA_ARGS__)
michael@0: #define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_FATAL
michael@0: const LogSeverity LOG_DCHECK = LOG_FATAL;
michael@0: 
michael@0: #else
michael@0: 
michael@0: #define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \
michael@0:   COMPACT_GOOGLE_LOG_EX_ERROR_REPORT(ClassName , ##__VA_ARGS__)
michael@0: #define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_ERROR_REPORT
michael@0: const LogSeverity LOG_DCHECK = LOG_ERROR_REPORT;
michael@0: #define DCHECK_IS_ON()                                                  \
michael@0:   ((::logging::get_dcheck_state() ==                                        \
michael@0:     ::logging::ENABLE_DCHECK_FOR_NON_OFFICIAL_RELEASE_BUILDS) &&        \
michael@0:    LOG_IS_ON(DCHECK))
michael@0: 
michael@0: #endif  // defined(DCHECK_ALWAYS_ON)
michael@0: 
michael@0: #else  // defined(NDEBUG)
michael@0: 
michael@0: // On a regular debug build, we want to have DCHECKs enabled.
michael@0: #define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \
michael@0:   COMPACT_GOOGLE_LOG_EX_FATAL(ClassName , ##__VA_ARGS__)
michael@0: #define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_FATAL
michael@0: const LogSeverity LOG_DCHECK = LOG_FATAL;
michael@0: #define DCHECK_IS_ON() true
michael@0: 
michael@0: #endif  // defined(NDEBUG)
michael@0: 
michael@0: #else  // ENABLE_DCHECK
michael@0: 
michael@0: // These are just dummy values since DCHECK_IS_ON() is always false in
michael@0: // this case.
michael@0: #define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \
michael@0:   COMPACT_GOOGLE_LOG_EX_INFO(ClassName , ##__VA_ARGS__)
michael@0: #define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_INFO
michael@0: const LogSeverity LOG_DCHECK = LOG_INFO;
michael@0: #define DCHECK_IS_ON() false
michael@0: 
michael@0: #endif  // ENABLE_DCHECK
michael@0: #undef ENABLE_DCHECK
michael@0: 
michael@0: // DCHECK et al. make sure to reference |condition| regardless of
michael@0: // whether DCHECKs are enabled; this is so that we don't get unused
michael@0: // variable warnings if the only use of a variable is in a DCHECK.
michael@0: // This behavior is different from DLOG_IF et al.
michael@0: 
michael@0: #define DCHECK(condition)                                           \
michael@0:   LAZY_STREAM(LOG_STREAM(DCHECK), DCHECK_IS_ON() && !(condition))   \
michael@0:   << "Check failed: " #condition ". "
michael@0: 
michael@0: #define DPCHECK(condition)                                          \
michael@0:   LAZY_STREAM(PLOG_STREAM(DCHECK), DCHECK_IS_ON() && !(condition))  \
michael@0:   << "Check failed: " #condition ". "
michael@0: 
michael@0: // Helper macro for binary operators.
michael@0: // Don't use this macro directly in your code, use DCHECK_EQ et al below.
michael@0: #define DCHECK_OP(name, op, val1, val2)                         \
michael@0:   if (DCHECK_IS_ON())                                           \
michael@0:     if (std::string* _result =                                  \
michael@0:         logging::Check##name##Impl((val1), (val2),              \
michael@0:                                    #val1 " " #op " " #val2))    \
michael@0:       logging::LogMessage(                                      \
michael@0:           __FILE__, __LINE__, ::logging::LOG_DCHECK,            \
michael@0:           _result).stream()
michael@0: 
michael@0: // Equality/Inequality checks - compare two values, and log a
michael@0: // LOG_DCHECK message including the two values when the result is not
michael@0: // as expected.  The values must have operator<<(ostream, ...)
michael@0: // defined.
michael@0: //
michael@0: // You may append to the error message like so:
michael@0: //   DCHECK_NE(1, 2) << ": The world must be ending!";
michael@0: //
michael@0: // We are very careful to ensure that each argument is evaluated exactly
michael@0: // once, and that anything which is legal to pass as a function argument is
michael@0: // legal here.  In particular, the arguments may be temporary expressions
michael@0: // which will end up being destroyed at the end of the apparent statement,
michael@0: // for example:
michael@0: //   DCHECK_EQ(string("abc")[1], 'b');
michael@0: //
michael@0: // WARNING: These may not compile correctly if one of the arguments is a pointer
michael@0: // and the other is NULL. To work around this, simply static_cast NULL to the
michael@0: // type of the desired pointer.
michael@0: 
michael@0: #define DCHECK_EQ(val1, val2) DCHECK_OP(EQ, ==, val1, val2)
michael@0: #define DCHECK_NE(val1, val2) DCHECK_OP(NE, !=, val1, val2)
michael@0: #define DCHECK_LE(val1, val2) DCHECK_OP(LE, <=, val1, val2)
michael@0: #define DCHECK_LT(val1, val2) DCHECK_OP(LT, < , val1, val2)
michael@0: #define DCHECK_GE(val1, val2) DCHECK_OP(GE, >=, val1, val2)
michael@0: #define DCHECK_GT(val1, val2) DCHECK_OP(GT, > , val1, val2)
michael@0: 
michael@0: #define NOTREACHED() DCHECK(false)
michael@0: 
michael@0: // Redefine the standard assert to use our nice log files
michael@0: #undef assert
michael@0: #define assert(x) DLOG_ASSERT(x)
michael@0: 
michael@0: // This class more or less represents a particular log message.  You
michael@0: // create an instance of LogMessage and then stream stuff to it.
michael@0: // When you finish streaming to it, ~LogMessage is called and the
michael@0: // full message gets streamed to the appropriate destination.
michael@0: //
michael@0: // You shouldn't actually use LogMessage's constructor to log things,
michael@0: // though.  You should use the LOG() macro (and variants thereof)
michael@0: // above.
michael@0: class BASE_EXPORT LogMessage {
michael@0:  public:
michael@0:   LogMessage(const char* file, int line, LogSeverity severity, int ctr);
michael@0: 
michael@0:   // Two special constructors that generate reduced amounts of code at
michael@0:   // LOG call sites for common cases.
michael@0:   //
michael@0:   // Used for LOG(INFO): Implied are:
michael@0:   // severity = LOG_INFO, ctr = 0
michael@0:   //
michael@0:   // Using this constructor instead of the more complex constructor above
michael@0:   // saves a couple of bytes per call site.
michael@0:   LogMessage(const char* file, int line);
michael@0: 
michael@0:   // Used for LOG(severity) where severity != INFO.  Implied
michael@0:   // are: ctr = 0
michael@0:   //
michael@0:   // Using this constructor instead of the more complex constructor above
michael@0:   // saves a couple of bytes per call site.
michael@0:   LogMessage(const char* file, int line, LogSeverity severity);
michael@0: 
michael@0:   // A special constructor used for check failures.  Takes ownership
michael@0:   // of the given string.
michael@0:   // Implied severity = LOG_FATAL
michael@0:   LogMessage(const char* file, int line, std::string* result);
michael@0: 
michael@0:   // A special constructor used for check failures, with the option to
michael@0:   // specify severity.  Takes ownership of the given string.
michael@0:   LogMessage(const char* file, int line, LogSeverity severity,
michael@0:              std::string* result);
michael@0: 
michael@0:   ~LogMessage();
michael@0: 
michael@0:   std::ostream& stream() { return stream_; }
michael@0: 
michael@0:  private:
michael@0:   void Init(const char* file, int line);
michael@0: 
michael@0:   LogSeverity severity_;
michael@0:   std::ostringstream stream_;
michael@0:   size_t message_start_;  // Offset of the start of the message (past prefix
michael@0:                           // info).
michael@0:   // The file and line information passed in to the constructor.
michael@0:   const char* file_;
michael@0:   const int line_;
michael@0: 
michael@0: #if defined(OS_WIN)
michael@0:   // Stores the current value of GetLastError in the constructor and restores
michael@0:   // it in the destructor by calling SetLastError.
michael@0:   // This is useful since the LogMessage class uses a lot of Win32 calls
michael@0:   // that will lose the value of GLE and the code that called the log function
michael@0:   // will have lost the thread error value when the log call returns.
michael@0:   class SaveLastError {
michael@0:    public:
michael@0:     SaveLastError();
michael@0:     ~SaveLastError();
michael@0: 
michael@0:     unsigned long get_error() const { return last_error_; }
michael@0: 
michael@0:    protected:
michael@0:     unsigned long last_error_;
michael@0:   };
michael@0: 
michael@0:   SaveLastError last_error_;
michael@0: #endif
michael@0: 
michael@0:   DISALLOW_COPY_AND_ASSIGN(LogMessage);
michael@0: };
michael@0: 
michael@0: // A non-macro interface to the log facility; (useful
michael@0: // when the logging level is not a compile-time constant).
michael@0: inline void LogAtLevel(int const log_level, std::string const &msg) {
michael@0:   LogMessage(__FILE__, __LINE__, log_level).stream() << msg;
michael@0: }
michael@0: 
michael@0: // This class is used to explicitly ignore values in the conditional
michael@0: // logging macros.  This avoids compiler warnings like "value computed
michael@0: // is not used" and "statement has no effect".
michael@0: class LogMessageVoidify {
michael@0:  public:
michael@0:   LogMessageVoidify() { }
michael@0:   // This has to be an operator with a precedence lower than << but
michael@0:   // higher than ?:
michael@0:   void operator&(std::ostream&) { }
michael@0: };
michael@0: 
michael@0: #if defined(OS_WIN)
michael@0: typedef unsigned long SystemErrorCode;
michael@0: #elif defined(OS_POSIX)
michael@0: typedef int SystemErrorCode;
michael@0: #endif
michael@0: 
michael@0: // Alias for ::GetLastError() on Windows and errno on POSIX. Avoids having to
michael@0: // pull in windows.h just for GetLastError() and DWORD.
michael@0: BASE_EXPORT SystemErrorCode GetLastSystemErrorCode();
michael@0: 
michael@0: #if defined(OS_WIN)
michael@0: // Appends a formatted system message of the GetLastError() type.
michael@0: class BASE_EXPORT Win32ErrorLogMessage {
michael@0:  public:
michael@0:   Win32ErrorLogMessage(const char* file,
michael@0:                        int line,
michael@0:                        LogSeverity severity,
michael@0:                        SystemErrorCode err,
michael@0:                        const char* module);
michael@0: 
michael@0:   Win32ErrorLogMessage(const char* file,
michael@0:                        int line,
michael@0:                        LogSeverity severity,
michael@0:                        SystemErrorCode err);
michael@0: 
michael@0:   // Appends the error message before destructing the encapsulated class.
michael@0:   ~Win32ErrorLogMessage();
michael@0: 
michael@0:   std::ostream& stream() { return log_message_.stream(); }
michael@0: 
michael@0:  private:
michael@0:   SystemErrorCode err_;
michael@0:   // Optional name of the module defining the error.
michael@0:   const char* module_;
michael@0:   LogMessage log_message_;
michael@0: 
michael@0:   DISALLOW_COPY_AND_ASSIGN(Win32ErrorLogMessage);
michael@0: };
michael@0: #elif defined(OS_POSIX)
michael@0: // Appends a formatted system message of the errno type
michael@0: class BASE_EXPORT ErrnoLogMessage {
michael@0:  public:
michael@0:   ErrnoLogMessage(const char* file,
michael@0:                   int line,
michael@0:                   LogSeverity severity,
michael@0:                   SystemErrorCode err);
michael@0: 
michael@0:   // Appends the error message before destructing the encapsulated class.
michael@0:   ~ErrnoLogMessage();
michael@0: 
michael@0:   std::ostream& stream() { return log_message_.stream(); }
michael@0: 
michael@0:  private:
michael@0:   SystemErrorCode err_;
michael@0:   LogMessage log_message_;
michael@0: 
michael@0:   DISALLOW_COPY_AND_ASSIGN(ErrnoLogMessage);
michael@0: };
michael@0: #endif  // OS_WIN
michael@0: 
michael@0: // Closes the log file explicitly if open.
michael@0: // NOTE: Since the log file is opened as necessary by the action of logging
michael@0: //       statements, there's no guarantee that it will stay closed
michael@0: //       after this call.
michael@0: BASE_EXPORT void CloseLogFile();
michael@0: 
michael@0: // Async signal safe logging mechanism.
michael@0: BASE_EXPORT void RawLog(int level, const char* message);
michael@0: 
michael@0: #define RAW_LOG(level, message) logging::RawLog(logging::LOG_ ## level, message)
michael@0: 
michael@0: #define RAW_CHECK(condition)                                                   \
michael@0:   do {                                                                         \
michael@0:     if (!(condition))                                                          \
michael@0:       logging::RawLog(logging::LOG_FATAL, "Check failed: " #condition "\n");   \
michael@0:   } while (0)
michael@0: 
michael@0: #if defined(OS_WIN)
michael@0: // Returns the default log file path.
michael@0: BASE_EXPORT std::wstring GetLogFileFullPath();
michael@0: #endif
michael@0: 
michael@0: }  // namespace logging
michael@0: 
michael@0: // These functions are provided as a convenience for logging, which is where we
michael@0: // use streams (it is against Google style to use streams in other places). It
michael@0: // is designed to allow you to emit non-ASCII Unicode strings to the log file,
michael@0: // which is normally ASCII. It is relatively slow, so try not to use it for
michael@0: // common cases. Non-ASCII characters will be converted to UTF-8 by these
michael@0: // operators.
michael@0: BASE_EXPORT std::ostream& operator<<(std::ostream& out, const wchar_t* wstr);
michael@0: inline std::ostream& operator<<(std::ostream& out, const std::wstring& wstr) {
michael@0:   return out << wstr.c_str();
michael@0: }
michael@0: 
michael@0: // The NOTIMPLEMENTED() macro annotates codepaths which have
michael@0: // not been implemented yet.
michael@0: //
michael@0: // The implementation of this macro is controlled by NOTIMPLEMENTED_POLICY:
michael@0: //   0 -- Do nothing (stripped by compiler)
michael@0: //   1 -- Warn at compile time
michael@0: //   2 -- Fail at compile time
michael@0: //   3 -- Fail at runtime (DCHECK)
michael@0: //   4 -- [default] LOG(ERROR) at runtime
michael@0: //   5 -- LOG(ERROR) at runtime, only once per call-site
michael@0: 
michael@0: #ifndef NOTIMPLEMENTED_POLICY
michael@0: #if defined(OS_ANDROID) && defined(OFFICIAL_BUILD)
michael@0: #define NOTIMPLEMENTED_POLICY 0
michael@0: #else
michael@0: // Select default policy: LOG(ERROR)
michael@0: #define NOTIMPLEMENTED_POLICY 4
michael@0: #endif
michael@0: #endif
michael@0: 
michael@0: #if defined(COMPILER_GCC)
michael@0: // On Linux, with GCC, we can use __PRETTY_FUNCTION__ to get the demangled name
michael@0: // of the current function in the NOTIMPLEMENTED message.
michael@0: #define NOTIMPLEMENTED_MSG "Not implemented reached in " << __PRETTY_FUNCTION__
michael@0: #else
michael@0: #define NOTIMPLEMENTED_MSG "NOT IMPLEMENTED"
michael@0: #endif
michael@0: 
michael@0: #if NOTIMPLEMENTED_POLICY == 0
michael@0: #define NOTIMPLEMENTED() EAT_STREAM_PARAMETERS
michael@0: #elif NOTIMPLEMENTED_POLICY == 1
michael@0: // TODO, figure out how to generate a warning
michael@0: #define NOTIMPLEMENTED() COMPILE_ASSERT(false, NOT_IMPLEMENTED)
michael@0: #elif NOTIMPLEMENTED_POLICY == 2
michael@0: #define NOTIMPLEMENTED() COMPILE_ASSERT(false, NOT_IMPLEMENTED)
michael@0: #elif NOTIMPLEMENTED_POLICY == 3
michael@0: #define NOTIMPLEMENTED() NOTREACHED()
michael@0: #elif NOTIMPLEMENTED_POLICY == 4
michael@0: #define NOTIMPLEMENTED() LOG(ERROR) << NOTIMPLEMENTED_MSG
michael@0: #elif NOTIMPLEMENTED_POLICY == 5
michael@0: #define NOTIMPLEMENTED() do {\
michael@0:   static bool logged_once = false;\
michael@0:   LOG_IF(ERROR, !logged_once) << NOTIMPLEMENTED_MSG;\
michael@0:   logged_once = true;\
michael@0: } while(0);\
michael@0: EAT_STREAM_PARAMETERS
michael@0: #endif
michael@0: 
michael@0: #endif  // BASE_LOGGING_H_