/* * Copyright 2004 The WebRTC Project Authors. All rights reserved. * * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be found * in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ // RTC_LOG(...) an ostream target that can be used to send formatted // output to a variety of logging targets, such as debugger console, stderr, // or any LogSink. // The severity level passed as the first argument to the logging // functions is used as a filter, to limit the verbosity of the logging. // Static members of LogMessage documented below are used to control the // verbosity and target of the output. // There are several variations on the RTC_LOG macro which facilitate logging // of common error conditions, detailed below. // RTC_LOG(sev) logs the given stream at severity "sev", which must be a // compile-time constant of the LoggingSeverity type, without the namespace // prefix. // RTC_LOG_V(sev) Like RTC_LOG(), but sev is a run-time variable of the // LoggingSeverity type (basically, it just doesn't prepend the namespace). // RTC_LOG_F(sev) Like RTC_LOG(), but includes the name of the current function. // RTC_LOG_T(sev) Like RTC_LOG(), but includes the this pointer. // RTC_LOG_T_F(sev) Like RTC_LOG_F(), but includes the this pointer. // RTC_LOG_GLE(sev [, mod]) attempt to add a string description of the // HRESULT returned by GetLastError. // RTC_LOG_ERRNO(sev) attempts to add a string description of an errno-derived // error. errno and associated facilities exist on both Windows and POSIX, // but on Windows they only apply to the C/C++ runtime. // RTC_LOG_ERR(sev) is an alias for the platform's normal error system, i.e. // _GLE on Windows and _ERRNO on POSIX. // (The above three also all have _EX versions that let you specify the error // code, rather than using the last one.) // RTC_LOG_E(sev, ctx, err, ...) logs a detailed error interpreted using the // specified context. // RTC_LOG_CHECK_LEVEL(sev) (and RTC_LOG_CHECK_LEVEL_V(sev)) can be used as a // test before performing expensive or sensitive operations whose sole // purpose is to output logging data at the desired level. #ifndef RTC_BASE_LOGGING_H_ #define RTC_BASE_LOGGING_H_ #include #include #include // no-presubmit-check TODO(webrtc:8982) #include #include #include "absl/base/attributes.h" #include "absl/meta/type_traits.h" #include "absl/strings/string_view.h" #include "rtc_base/constructor_magic.h" #include "rtc_base/strings/string_builder.h" #include "rtc_base/system/inline.h" #if !defined(NDEBUG) || defined(DLOG_ALWAYS_ON) #define RTC_DLOG_IS_ON 1 #else #define RTC_DLOG_IS_ON 0 #endif #if defined(RTC_DISABLE_LOGGING) #define RTC_LOG_ENABLED() 0 #else #define RTC_LOG_ENABLED() 1 #endif namespace rtc { ////////////////////////////////////////////////////////////////////// // Note that the non-standard LoggingSeverity aliases exist because they are // still in broad use. The meanings of the levels are: // LS_VERBOSE: This level is for data which we do not want to appear in the // normal debug log, but should appear in diagnostic logs. // LS_INFO: Chatty level used in debugging for all sorts of things, the default // in debug builds. // LS_WARNING: Something that may warrant investigation. // LS_ERROR: Something that should not have occurred. // LS_NONE: Don't log. enum LoggingSeverity { LS_VERBOSE, LS_INFO, LS_WARNING, LS_ERROR, LS_NONE, INFO = LS_INFO, WARNING = LS_WARNING, LERROR = LS_ERROR }; // LogErrorContext assists in interpreting the meaning of an error value. enum LogErrorContext { ERRCTX_NONE, ERRCTX_ERRNO, // System-local errno ERRCTX_HRESULT, // Windows HRESULT // Abbreviations for LOG_E macro ERRCTX_EN = ERRCTX_ERRNO, // LOG_E(sev, EN, x) ERRCTX_HR = ERRCTX_HRESULT, // LOG_E(sev, HR, x) }; class LogMessage; // Virtual sink interface that can receive log messages. class LogSink { public: LogSink() {} virtual ~LogSink() {} virtual void OnLogMessage(const std::string& msg, LoggingSeverity severity, const char* tag); virtual void OnLogMessage(const std::string& message, LoggingSeverity severity); virtual void OnLogMessage(const std::string& message) = 0; private: friend class ::rtc::LogMessage; #if RTC_LOG_ENABLED() // Members for LogMessage class to keep linked list of the registered sinks. LogSink* next_ = nullptr; LoggingSeverity min_severity_; #endif }; namespace webrtc_logging_impl { class LogMetadata { public: LogMetadata(const char* file, int line, LoggingSeverity severity) : file_(file), line_and_sev_(static_cast(line) << 3 | severity) {} LogMetadata() = default; const char* File() const { return file_; } int Line() const { return line_and_sev_ >> 3; } LoggingSeverity Severity() const { return static_cast(line_and_sev_ & 0x7); } private: const char* file_; // Line number and severity, the former in the most significant 29 bits, the // latter in the least significant 3 bits. (This is an optimization; since // both numbers are usually compile-time constants, this way we can load them // both with a single instruction.) uint32_t line_and_sev_; }; static_assert(std::is_trivial::value, ""); struct LogMetadataErr { LogMetadata meta; LogErrorContext err_ctx; int err; }; #ifdef WEBRTC_ANDROID struct LogMetadataTag { LoggingSeverity severity; const char* tag; }; #endif enum class LogArgType : int8_t { kEnd = 0, kInt, kLong, kLongLong, kUInt, kULong, kULongLong, kDouble, kLongDouble, kCharP, kStdString, kStringView, kVoidP, kLogMetadata, kLogMetadataErr, #ifdef WEBRTC_ANDROID kLogMetadataTag, #endif }; // Wrapper for log arguments. Only ever make values of this type with the // MakeVal() functions. template struct Val { static constexpr LogArgType Type() { return N; } T GetVal() const { return val; } T val; }; // Case for when we need to construct a temp string and then print that. // (We can't use Val // because we need somewhere to store the temp string.) struct ToStringVal { static constexpr LogArgType Type() { return LogArgType::kStdString; } const std::string* GetVal() const { return &val; } std::string val; }; inline Val MakeVal(int x) { return {x}; } inline Val MakeVal(long x) { return {x}; } inline Val MakeVal(long long x) { return {x}; } inline Val MakeVal(unsigned int x) { return {x}; } inline Val MakeVal(unsigned long x) { return {x}; } inline Val MakeVal( unsigned long long x) { return {x}; } inline Val MakeVal(double x) { return {x}; } inline Val MakeVal(long double x) { return {x}; } inline Val MakeVal(const char* x) { return {x}; } inline Val MakeVal( const std::string& x) { return {&x}; } inline Val MakeVal( const absl::string_view& x) { return {&x}; } inline Val MakeVal(const void* x) { return {x}; } inline Val MakeVal( const LogMetadata& x) { return {x}; } inline Val MakeVal( const LogMetadataErr& x) { return {x}; } // The enum class types are not implicitly convertible to arithmetic types. template ::value && !std::is_arithmetic::value>* = nullptr> inline decltype(MakeVal(std::declval>())) MakeVal( T x) { return {static_cast>(x)}; } #ifdef WEBRTC_ANDROID inline Val MakeVal( const LogMetadataTag& x) { return {x}; } #endif template struct has_to_log_string : std::false_type {}; template struct has_to_log_string()))> : std::true_type {}; // Handle arbitrary types other than the above by falling back to stringstream. // TODO(bugs.webrtc.org/9278): Get rid of this overload when callers don't need // it anymore. No in-tree caller does, but some external callers still do. template < typename T, typename T1 = absl::decay_t, absl::enable_if_t::value && !std::is_same::value && !std::is_same::value && !has_to_log_string::value && #ifdef WEBRTC_ANDROID !std::is_same::value && #endif !std::is_same::value>* = nullptr> ToStringVal MakeVal(const T& x) { std::ostringstream os; // no-presubmit-check TODO(webrtc:8982) os << x; return {os.str()}; } template ::value>* = nullptr> ToStringVal MakeVal(const T& x) { return {ToLogString(x)}; } #if RTC_LOG_ENABLED() void Log(const LogArgType* fmt, ...); #else inline void Log(const LogArgType* fmt, ...) { // Do nothing, shouldn't be invoked } #endif // Ephemeral type that represents the result of the logging << operator. template class LogStreamer; // Base case: Before the first << argument. template <> class LogStreamer<> final { public: template ())), absl::enable_if_t::value || std::is_enum::value>* = nullptr> RTC_FORCE_INLINE LogStreamer operator<<(U arg) const { return LogStreamer(MakeVal(arg), this); } template ())), absl::enable_if_t::value && !std::is_enum::value>* = nullptr> RTC_FORCE_INLINE LogStreamer operator<<(const U& arg) const { return LogStreamer(MakeVal(arg), this); } template RTC_FORCE_INLINE static void Call(const Us&... args) { static constexpr LogArgType t[] = {Us::Type()..., LogArgType::kEnd}; Log(t, args.GetVal()...); } }; // Inductive case: We've already seen at least one << argument. The most recent // one had type `T`, and the earlier ones had types `Ts`. template class LogStreamer final { public: RTC_FORCE_INLINE LogStreamer(T arg, const LogStreamer* prior) : arg_(arg), prior_(prior) {} template ())), absl::enable_if_t::value || std::is_enum::value>* = nullptr> RTC_FORCE_INLINE LogStreamer operator<<(U arg) const { return LogStreamer(MakeVal(arg), this); } template ())), absl::enable_if_t::value && !std::is_enum::value>* = nullptr> RTC_FORCE_INLINE LogStreamer operator<<(const U& arg) const { return LogStreamer(MakeVal(arg), this); } template RTC_FORCE_INLINE void Call(const Us&... args) const { prior_->Call(arg_, args...); } private: // The most recent argument. T arg_; // Earlier arguments. const LogStreamer* prior_; }; class LogCall final { public: // This can be any binary operator with precedence lower than <<. // We return bool here to be able properly remove logging if // RTC_DISABLE_LOGGING is defined. template RTC_FORCE_INLINE bool operator&(const LogStreamer& streamer) { streamer.Call(); return true; } }; // This class is used to explicitly ignore values in the conditional // logging macros. This avoids compiler warnings like "value computed // is not used" and "statement has no effect". class LogMessageVoidify { public: LogMessageVoidify() = default; // This has to be an operator with a precedence lower than << but // higher than ?: template void operator&(LogStreamer&& streamer) {} }; } // namespace webrtc_logging_impl // Direct use of this class is deprecated; please use the logging macros // instead. // TODO(bugs.webrtc.org/9278): Move this class to an unnamed namespace in the // .cc file. class LogMessage { public: // Same as the above, but using a compile-time constant for the logging // severity. This saves space at the call site, since passing an empty struct // is generally the same as not passing an argument at all. template RTC_NO_INLINE LogMessage(const char* file, int line, std::integral_constant) : LogMessage(file, line, S) {} #if RTC_LOG_ENABLED() LogMessage(const char* file, int line, LoggingSeverity sev); LogMessage(const char* file, int line, LoggingSeverity sev, LogErrorContext err_ctx, int err); #if defined(WEBRTC_ANDROID) LogMessage(const char* file, int line, LoggingSeverity sev, const char* tag); #endif // DEPRECATED - DO NOT USE - PLEASE USE THE MACROS INSTEAD OF THE CLASS. // Android code should use the 'const char*' version since tags are static // and we want to avoid allocating a std::string copy per log line. ABSL_DEPRECATED("Use RTC_LOG macros instead of accessing this class directly") LogMessage(const char* file, int line, LoggingSeverity sev, const std::string& tag); ~LogMessage(); void AddTag(const char* tag); rtc::StringBuilder& stream(); // Returns the time at which this function was called for the first time. // The time will be used as the logging start time. // If this is not called externally, the LogMessage ctor also calls it, in // which case the logging start time will be the time of the first LogMessage // instance is created. static int64_t LogStartTime(); // Returns the wall clock equivalent of |LogStartTime|, in seconds from the // epoch. static uint32_t WallClockStartTime(); // LogThreads: Display the thread identifier of the current thread static void LogThreads(bool on = true); // LogTimestamps: Display the elapsed time of the program static void LogTimestamps(bool on = true); // These are the available logging channels // Debug: Debug console on Windows, otherwise stderr static void LogToDebug(LoggingSeverity min_sev); static LoggingSeverity GetLogToDebug(); // Sets whether logs will be directed to stderr in debug mode. static void SetLogToStderr(bool log_to_stderr); // Stream: Any non-blocking stream interface. // Installs the |stream| to collect logs with severtiy |min_sev| or higher. // |stream| must live until deinstalled by RemoveLogToStream. // If |stream| is the first stream added to the system, we might miss some // early concurrent log statement happening from another thread happening near // this instant. static void AddLogToStream(LogSink* stream, LoggingSeverity min_sev); // Removes the specified stream, without destroying it. When the method // has completed, it's guaranteed that |stream| will receive no more logging // calls. static void RemoveLogToStream(LogSink* stream); // Returns the severity for the specified stream, of if none is specified, // the minimum stream severity. static int GetLogToStream(LogSink* stream = nullptr); // Testing against MinLogSeverity allows code to avoid potentially expensive // logging operations by pre-checking the logging level. static int GetMinLogSeverity(); // Parses the provided parameter stream to configure the options above. // Useful for configuring logging from the command line. static void ConfigureLogging(const char* params); // Checks the current global debug severity and if the |streams_| collection // is empty. If |severity| is smaller than the global severity and if the // |streams_| collection is empty, the LogMessage will be considered a noop // LogMessage. static bool IsNoop(LoggingSeverity severity); // Version of IsNoop that uses fewer instructions at the call site, since the // caller doesn't have to pass an argument. template RTC_NO_INLINE static bool IsNoop() { return IsNoop(S); } #else // Next methods do nothing; no one will call these functions. LogMessage(const char* file, int line, LoggingSeverity sev) {} LogMessage(const char* file, int line, LoggingSeverity sev, LogErrorContext err_ctx, int err) {} #if defined(WEBRTC_ANDROID) LogMessage(const char* file, int line, LoggingSeverity sev, const char* tag) { } #endif // DEPRECATED - DO NOT USE - PLEASE USE THE MACROS INSTEAD OF THE CLASS. // Android code should use the 'const char*' version since tags are static // and we want to avoid allocating a std::string copy per log line. ABSL_DEPRECATED("Use RTC_LOG macros instead of accessing this class directly") LogMessage(const char* file, int line, LoggingSeverity sev, const std::string& tag) {} ~LogMessage() = default; inline void AddTag(const char* tag) {} inline rtc::StringBuilder& stream() { return print_stream_; } inline static int64_t LogStartTime() { return 0; } inline static uint32_t WallClockStartTime() { return 0; } inline static void LogThreads(bool on = true) {} inline static void LogTimestamps(bool on = true) {} inline static void LogToDebug(LoggingSeverity min_sev) {} inline static LoggingSeverity GetLogToDebug() { return LoggingSeverity::LS_INFO; } inline static void SetLogToStderr(bool log_to_stderr) {} inline static void AddLogToStream(LogSink* stream, LoggingSeverity min_sev) {} inline static void RemoveLogToStream(LogSink* stream) {} inline static int GetLogToStream(LogSink* stream = nullptr) { return 0; } inline static int GetMinLogSeverity() { return 0; } inline static void ConfigureLogging(const char* params) {} static constexpr bool IsNoop(LoggingSeverity severity) { return true; } template static constexpr bool IsNoop() { return IsNoop(S); } #endif // RTC_LOG_ENABLED() private: friend class LogMessageForTesting; #if RTC_LOG_ENABLED() // Updates min_sev_ appropriately when debug sinks change. static void UpdateMinLogSeverity(); // These write out the actual log messages. #if defined(WEBRTC_ANDROID) static void OutputToDebug(const std::string& msg, LoggingSeverity severity, const char* tag); #else static void OutputToDebug(const std::string& msg, LoggingSeverity severity); #endif // defined(WEBRTC_ANDROID) // Called from the dtor (or from a test) to append optional extra error // information to the log stream and a newline character. void FinishPrintStream(); // The severity level of this message LoggingSeverity severity_; #if defined(WEBRTC_ANDROID) // The default Android debug output tag. const char* tag_ = "libjingle"; #endif // String data generated in the constructor, that should be appended to // the message before output. std::string extra_; // The output streams and their associated severities static LogSink* streams_; // Holds true with high probability if |streams_| is empty, false with high // probability otherwise. Operated on with std::memory_order_relaxed because // it's ok to lose or log some additional statements near the instant streams // are added/removed. static std::atomic streams_empty_; // Flags for formatting options static bool thread_, timestamp_; // Determines if logs will be directed to stderr in debug mode. static bool log_to_stderr_; #else // RTC_LOG_ENABLED() // Next methods do nothing; no one will call these functions. inline static void UpdateMinLogSeverity() {} #if defined(WEBRTC_ANDROID) inline static void OutputToDebug(const std::string& msg, LoggingSeverity severity, const char* tag) {} #else inline static void OutputToDebug(const std::string& msg, LoggingSeverity severity) {} #endif // defined(WEBRTC_ANDROID) inline void FinishPrintStream() {} #endif // RTC_LOG_ENABLED() // The stringbuilder that buffers the formatted message before output rtc::StringBuilder print_stream_; RTC_DISALLOW_COPY_AND_ASSIGN(LogMessage); }; ////////////////////////////////////////////////////////////////////// // Logging Helpers ////////////////////////////////////////////////////////////////////// #define RTC_LOG_FILE_LINE(sev, file, line) \ ::rtc::webrtc_logging_impl::LogCall() & \ ::rtc::webrtc_logging_impl::LogStreamer<>() \ << ::rtc::webrtc_logging_impl::LogMetadata(file, line, sev) #define RTC_LOG(sev) \ !rtc::LogMessage::IsNoop<::rtc::sev>() && \ RTC_LOG_FILE_LINE(::rtc::sev, __FILE__, __LINE__) // The _V version is for when a variable is passed in. #define RTC_LOG_V(sev) \ !rtc::LogMessage::IsNoop(sev) && RTC_LOG_FILE_LINE(sev, __FILE__, __LINE__) // The _F version prefixes the message with the current function name. #if (defined(__GNUC__) && !defined(NDEBUG)) || defined(WANT_PRETTY_LOG_F) #define RTC_LOG_F(sev) RTC_LOG(sev) << __PRETTY_FUNCTION__ << ": " #define RTC_LOG_T_F(sev) \ RTC_LOG(sev) << this << ": " << __PRETTY_FUNCTION__ << ": " #else #define RTC_LOG_F(sev) RTC_LOG(sev) << __FUNCTION__ << ": " #define RTC_LOG_T_F(sev) RTC_LOG(sev) << this << ": " << __FUNCTION__ << ": " #endif #define RTC_LOG_CHECK_LEVEL(sev) ::rtc::LogCheckLevel(::rtc::sev) #define RTC_LOG_CHECK_LEVEL_V(sev) ::rtc::LogCheckLevel(sev) inline bool LogCheckLevel(LoggingSeverity sev) { return (LogMessage::GetMinLogSeverity() <= sev); } #define RTC_LOG_E(sev, ctx, err) \ !rtc::LogMessage::IsNoop<::rtc::sev>() && \ ::rtc::webrtc_logging_impl::LogCall() & \ ::rtc::webrtc_logging_impl::LogStreamer<>() \ << ::rtc::webrtc_logging_impl::LogMetadataErr { \ {__FILE__, __LINE__, ::rtc::sev}, ::rtc::ERRCTX_##ctx, (err) \ } #define RTC_LOG_T(sev) RTC_LOG(sev) << this << ": " #define RTC_LOG_ERRNO_EX(sev, err) RTC_LOG_E(sev, ERRNO, err) #define RTC_LOG_ERRNO(sev) RTC_LOG_ERRNO_EX(sev, errno) #if defined(WEBRTC_WIN) #define RTC_LOG_GLE_EX(sev, err) RTC_LOG_E(sev, HRESULT, err) #define RTC_LOG_GLE(sev) RTC_LOG_GLE_EX(sev, static_cast(GetLastError())) #define RTC_LOG_ERR_EX(sev, err) RTC_LOG_GLE_EX(sev, err) #define RTC_LOG_ERR(sev) RTC_LOG_GLE(sev) #elif defined(__native_client__) && __native_client__ #define RTC_LOG_ERR_EX(sev, err) RTC_LOG(sev) #define RTC_LOG_ERR(sev) RTC_LOG(sev) #elif defined(WEBRTC_POSIX) #define RTC_LOG_ERR_EX(sev, err) RTC_LOG_ERRNO_EX(sev, err) #define RTC_LOG_ERR(sev) RTC_LOG_ERRNO(sev) #endif // WEBRTC_WIN #ifdef WEBRTC_ANDROID namespace webrtc_logging_impl { // TODO(kwiberg): Replace these with absl::string_view. inline const char* AdaptString(const char* str) { return str; } inline const char* AdaptString(const std::string& str) { return str.c_str(); } } // namespace webrtc_logging_impl #define RTC_LOG_TAG(sev, tag) \ !rtc::LogMessage::IsNoop(sev) && \ ::rtc::webrtc_logging_impl::LogCall() & \ ::rtc::webrtc_logging_impl::LogStreamer<>() \ << ::rtc::webrtc_logging_impl::LogMetadataTag { \ sev, ::rtc::webrtc_logging_impl::AdaptString(tag) \ } #else // DEPRECATED. This macro is only intended for Android. #define RTC_LOG_TAG(sev, tag) RTC_LOG_V(sev) #endif // The RTC_DLOG macros are equivalent to their RTC_LOG counterparts except that // they only generate code in debug builds. #if RTC_DLOG_IS_ON #define RTC_DLOG(sev) RTC_LOG(sev) #define RTC_DLOG_V(sev) RTC_LOG_V(sev) #define RTC_DLOG_F(sev) RTC_LOG_F(sev) #else #define RTC_DLOG_EAT_STREAM_PARAMS() \ while (false) \ ::rtc::webrtc_logging_impl::LogMessageVoidify() & \ (::rtc::webrtc_logging_impl::LogStreamer<>()) #define RTC_DLOG(sev) RTC_DLOG_EAT_STREAM_PARAMS() #define RTC_DLOG_V(sev) RTC_DLOG_EAT_STREAM_PARAMS() #define RTC_DLOG_F(sev) RTC_DLOG_EAT_STREAM_PARAMS() #endif } // namespace rtc #endif // RTC_BASE_LOGGING_H_