Line data Source code
1 : /*
2 : * Copyright 2004 The WebRTC Project Authors. All rights reserved.
3 : *
4 : * Use of this source code is governed by a BSD-style license
5 : * that can be found in the LICENSE file in the root of the source
6 : * tree. An additional intellectual property rights grant can be found
7 : * in the file PATENTS. All contributing project authors may
8 : * be found in the AUTHORS file in the root of the source tree.
9 : */
10 :
11 : // LOG(...) an ostream target that can be used to send formatted
12 : // output to a variety of logging targets, such as debugger console, stderr,
13 : // or any LogSink.
14 : // The severity level passed as the first argument to the LOGging
15 : // functions is used as a filter, to limit the verbosity of the logging.
16 : // Static members of LogMessage documented below are used to control the
17 : // verbosity and target of the output.
18 : // There are several variations on the LOG macro which facilitate logging
19 : // of common error conditions, detailed below.
20 :
21 : // LOG(sev) logs the given stream at severity "sev", which must be a
22 : // compile-time constant of the LoggingSeverity type, without the namespace
23 : // prefix.
24 : // LOG_V(sev) Like LOG(), but sev is a run-time variable of the LoggingSeverity
25 : // type (basically, it just doesn't prepend the namespace).
26 : // LOG_F(sev) Like LOG(), but includes the name of the current function.
27 : // LOG_T(sev) Like LOG(), but includes the this pointer.
28 : // LOG_T_F(sev) Like LOG_F(), but includes the this pointer.
29 : // LOG_GLE(M)(sev [, mod]) attempt to add a string description of the
30 : // HRESULT returned by GetLastError. The "M" variant allows searching of a
31 : // DLL's string table for the error description.
32 : // LOG_ERRNO(sev) attempts to add a string description of an errno-derived
33 : // error. errno and associated facilities exist on both Windows and POSIX,
34 : // but on Windows they only apply to the C/C++ runtime.
35 : // LOG_ERR(sev) is an alias for the platform's normal error system, i.e. _GLE on
36 : // Windows and _ERRNO on POSIX.
37 : // (The above three also all have _EX versions that let you specify the error
38 : // code, rather than using the last one.)
39 : // LOG_E(sev, ctx, err, ...) logs a detailed error interpreted using the
40 : // specified context.
41 : // LOG_CHECK_LEVEL(sev) (and LOG_CHECK_LEVEL_V(sev)) can be used as a test
42 : // before performing expensive or sensitive operations whose sole purpose is
43 : // to output logging data at the desired level.
44 : // Lastly, PLOG(sev, err) is an alias for LOG_ERR_EX.
45 :
46 : #ifndef WEBRTC_BASE_LOGGING_H_
47 : #define WEBRTC_BASE_LOGGING_H_
48 :
49 : #include <errno.h>
50 :
51 : #include <list>
52 : #include <sstream>
53 : #include <string>
54 : #include <utility>
55 :
56 : #if defined(WEBRTC_MAC) && !defined(WEBRTC_IOS)
57 : #include <CoreServices/CoreServices.h>
58 : #endif
59 :
60 : #include "webrtc/base/basictypes.h"
61 : #include "webrtc/base/constructormagic.h"
62 : #include "webrtc/base/thread_annotations.h"
63 :
64 : namespace rtc {
65 :
66 : ///////////////////////////////////////////////////////////////////////////////
67 : // ConstantLabel can be used to easily generate string names from constant
68 : // values. This can be useful for logging descriptive names of error messages.
69 : // Usage:
70 : // const ConstantLabel LIBRARY_ERRORS[] = {
71 : // KLABEL(SOME_ERROR),
72 : // KLABEL(SOME_OTHER_ERROR),
73 : // ...
74 : // LASTLABEL
75 : // }
76 : //
77 : // int err = LibraryFunc();
78 : // LOG(LS_ERROR) << "LibraryFunc returned: "
79 : // << ErrorName(err, LIBRARY_ERRORS);
80 :
81 : struct ConstantLabel { int value; const char * label; };
82 : #define KLABEL(x) { x, #x }
83 : #define TLABEL(x, y) { x, y }
84 : #define LASTLABEL { 0, 0 }
85 :
86 : const char* FindLabel(int value, const ConstantLabel entries[]);
87 : std::string ErrorName(int err, const ConstantLabel* err_table);
88 :
89 : #if defined(WEBRTC_MAC) && !defined(WEBRTC_IOS)
90 : // Returns a UTF8 description from an OS X Status error.
91 : std::string DescriptionFromOSStatus(OSStatus err);
92 : #endif
93 :
94 : //////////////////////////////////////////////////////////////////////
95 :
96 : // Note that the non-standard LoggingSeverity aliases exist because they are
97 : // still in broad use. The meanings of the levels are:
98 : // LS_SENSITIVE: Information which should only be logged with the consent
99 : // of the user, due to privacy concerns.
100 : // LS_VERBOSE: This level is for data which we do not want to appear in the
101 : // normal debug log, but should appear in diagnostic logs.
102 : // LS_INFO: Chatty level used in debugging for all sorts of things, the default
103 : // in debug builds.
104 : // LS_WARNING: Something that may warrant investigation.
105 : // LS_ERROR: Something that should not have occurred.
106 : // LS_NONE: Don't log.
107 : enum LoggingSeverity {
108 : LS_SENSITIVE,
109 : LS_VERBOSE,
110 : LS_INFO,
111 : LS_WARNING,
112 : LS_ERROR,
113 : LS_NONE,
114 : INFO = LS_INFO,
115 : WARNING = LS_WARNING,
116 : LERROR = LS_ERROR
117 : };
118 :
119 : // LogErrorContext assists in interpreting the meaning of an error value.
120 : enum LogErrorContext {
121 : ERRCTX_NONE,
122 : ERRCTX_ERRNO, // System-local errno
123 : ERRCTX_HRESULT, // Windows HRESULT
124 : ERRCTX_OSSTATUS, // MacOS OSStatus
125 :
126 : // Abbreviations for LOG_E macro
127 : ERRCTX_EN = ERRCTX_ERRNO, // LOG_E(sev, EN, x)
128 : ERRCTX_HR = ERRCTX_HRESULT, // LOG_E(sev, HR, x)
129 : ERRCTX_OS = ERRCTX_OSSTATUS, // LOG_E(sev, OS, x)
130 : };
131 :
132 : // Virtual sink interface that can receive log messages.
133 : class LogSink {
134 : public:
135 0 : LogSink() {}
136 0 : virtual ~LogSink() {}
137 : virtual void OnLogMessage(const std::string& message) = 0;
138 : };
139 :
140 : class LogMessage {
141 : public:
142 : LogMessage(const char* file, int line, LoggingSeverity sev,
143 : LogErrorContext err_ctx = ERRCTX_NONE, int err = 0,
144 : const char* module = NULL);
145 :
146 : LogMessage(const char* file,
147 : int line,
148 : LoggingSeverity sev,
149 : const std::string& tag);
150 :
151 : ~LogMessage();
152 :
153 0 : static inline bool Loggable(LoggingSeverity sev) { return (sev >= min_sev_); }
154 0 : std::ostream& stream() { return print_stream_; }
155 :
156 : // Returns the time at which this function was called for the first time.
157 : // The time will be used as the logging start time.
158 : // If this is not called externally, the LogMessage ctor also calls it, in
159 : // which case the logging start time will be the time of the first LogMessage
160 : // instance is created.
161 : static int64_t LogStartTime();
162 :
163 : // Returns the wall clock equivalent of |LogStartTime|, in seconds from the
164 : // epoch.
165 : static uint32_t WallClockStartTime();
166 :
167 : // LogThreads: Display the thread identifier of the current thread
168 : static void LogThreads(bool on = true);
169 :
170 : // LogTimestamps: Display the elapsed time of the program
171 : static void LogTimestamps(bool on = true);
172 :
173 : // These are the available logging channels
174 : // Debug: Debug console on Windows, otherwise stderr
175 : static void LogToDebug(LoggingSeverity min_sev);
176 0 : static LoggingSeverity GetLogToDebug() { return dbg_sev_; }
177 :
178 : // Sets whether logs will be directed to stderr in debug mode.
179 : static void SetLogToStderr(bool log_to_stderr);
180 :
181 : // Stream: Any non-blocking stream interface. LogMessage takes ownership of
182 : // the stream. Multiple streams may be specified by using AddLogToStream.
183 : // LogToStream is retained for backwards compatibility; when invoked, it
184 : // will discard any previously set streams and install the specified stream.
185 : // GetLogToStream gets the severity for the specified stream, of if none
186 : // is specified, the minimum stream severity.
187 : // RemoveLogToStream removes the specified stream, without destroying it.
188 : static int GetLogToStream(LogSink* stream = NULL);
189 : static void AddLogToStream(LogSink* stream, LoggingSeverity min_sev);
190 : static void RemoveLogToStream(LogSink* stream);
191 :
192 : // Testing against MinLogSeverity allows code to avoid potentially expensive
193 : // logging operations by pre-checking the logging level.
194 0 : static int GetMinLogSeverity() { return min_sev_; }
195 :
196 : // Parses the provided parameter stream to configure the options above.
197 : // Useful for configuring logging from the command line.
198 : static void ConfigureLogging(const char* params);
199 :
200 : private:
201 : typedef std::pair<LogSink*, LoggingSeverity> StreamAndSeverity;
202 : typedef std::list<StreamAndSeverity> StreamList;
203 :
204 : // Updates min_sev_ appropriately when debug sinks change.
205 : static void UpdateMinLogSeverity();
206 :
207 : // These write out the actual log messages.
208 : static void OutputToDebug(const std::string& msg,
209 : LoggingSeverity severity,
210 : const std::string& tag);
211 :
212 : // The ostream that buffers the formatted message before output
213 : std::ostringstream print_stream_;
214 :
215 : // The severity level of this message
216 : LoggingSeverity severity_;
217 :
218 : // The Android debug output tag.
219 : std::string tag_;
220 :
221 : // String data generated in the constructor, that should be appended to
222 : // the message before output.
223 : std::string extra_;
224 :
225 : // dbg_sev_ is the thresholds for those output targets
226 : // min_sev_ is the minimum (most verbose) of those levels, and is used
227 : // as a short-circuit in the logging macros to identify messages that won't
228 : // be logged.
229 : // ctx_sev_ is the minimum level at which file context is displayed
230 : static LoggingSeverity min_sev_, dbg_sev_, ctx_sev_;
231 :
232 : // The output streams and their associated severities
233 : static StreamList streams_;
234 :
235 : // Flags for formatting options
236 : static bool thread_, timestamp_;
237 :
238 : // Determines if logs will be directed to stderr in debug mode.
239 : static bool log_to_stderr_;
240 :
241 : RTC_DISALLOW_COPY_AND_ASSIGN(LogMessage);
242 : };
243 :
244 : //////////////////////////////////////////////////////////////////////
245 : // Logging Helpers
246 : //////////////////////////////////////////////////////////////////////
247 :
248 : class LogMultilineState {
249 : public:
250 : size_t unprintable_count_[2];
251 : LogMultilineState() {
252 : unprintable_count_[0] = unprintable_count_[1] = 0;
253 : }
254 : };
255 :
256 : // When possible, pass optional state variable to track various data across
257 : // multiple calls to LogMultiline. Otherwise, pass NULL.
258 : void LogMultiline(LoggingSeverity level, const char* label, bool input,
259 : const void* data, size_t len, bool hex_mode,
260 : LogMultilineState* state);
261 :
262 : #ifndef LOG
263 :
264 : // The following non-obvious technique for implementation of a
265 : // conditional log stream was stolen from google3/base/logging.h.
266 :
267 : // This class is used to explicitly ignore values in the conditional
268 : // logging macros. This avoids compiler warnings like "value computed
269 : // is not used" and "statement has no effect".
270 :
271 : class LogMessageVoidify {
272 : public:
273 0 : LogMessageVoidify() { }
274 : // This has to be an operator with a precedence lower than << but
275 : // higher than ?:
276 0 : void operator&(std::ostream&) { }
277 : };
278 :
279 : #define LOG_SEVERITY_PRECONDITION(sev) \
280 : !(rtc::LogMessage::Loggable(sev)) \
281 : ? (void) 0 \
282 : : rtc::LogMessageVoidify() &
283 :
284 : #define LOG(sev) \
285 : LOG_SEVERITY_PRECONDITION(rtc::sev) \
286 : rtc::LogMessage(__FILE__, __LINE__, rtc::sev).stream()
287 :
288 : // The _V version is for when a variable is passed in. It doesn't do the
289 : // namespace concatination.
290 : #define LOG_V(sev) \
291 : LOG_SEVERITY_PRECONDITION(sev) \
292 : rtc::LogMessage(__FILE__, __LINE__, sev).stream()
293 :
294 : // The _F version prefixes the message with the current function name.
295 : #if (defined(__GNUC__) && !defined(NDEBUG)) || defined(WANT_PRETTY_LOG_F)
296 : #define LOG_F(sev) LOG(sev) << __PRETTY_FUNCTION__ << ": "
297 : #define LOG_T_F(sev) LOG(sev) << this << ": " << __PRETTY_FUNCTION__ << ": "
298 : #else
299 : #define LOG_F(sev) LOG(sev) << __FUNCTION__ << ": "
300 : #define LOG_T_F(sev) LOG(sev) << this << ": " << __FUNCTION__ << ": "
301 : #endif
302 :
303 : #define LOG_CHECK_LEVEL(sev) \
304 : rtc::LogCheckLevel(rtc::sev)
305 : #define LOG_CHECK_LEVEL_V(sev) \
306 : rtc::LogCheckLevel(sev)
307 :
308 0 : inline bool LogCheckLevel(LoggingSeverity sev) {
309 0 : return (LogMessage::GetMinLogSeverity() <= sev);
310 : }
311 :
312 : #define LOG_E(sev, ctx, err, ...) \
313 : LOG_SEVERITY_PRECONDITION(rtc::sev) \
314 : rtc::LogMessage(__FILE__, __LINE__, rtc::sev, \
315 : rtc::ERRCTX_ ## ctx, err , ##__VA_ARGS__) \
316 : .stream()
317 :
318 : #define LOG_T(sev) LOG(sev) << this << ": "
319 :
320 : #define LOG_ERRNO_EX(sev, err) \
321 : LOG_E(sev, ERRNO, err)
322 : #define LOG_ERRNO(sev) \
323 : LOG_ERRNO_EX(sev, errno)
324 :
325 : #if defined(WEBRTC_WIN)
326 : #define LOG_GLE_EX(sev, err) \
327 : LOG_E(sev, HRESULT, err)
328 : #define LOG_GLE(sev) \
329 : LOG_GLE_EX(sev, GetLastError())
330 : #define LOG_GLEM(sev, mod) \
331 : LOG_E(sev, HRESULT, GetLastError(), mod)
332 : #define LOG_ERR_EX(sev, err) \
333 : LOG_GLE_EX(sev, err)
334 : #define LOG_ERR(sev) \
335 : LOG_GLE(sev)
336 : #define LAST_SYSTEM_ERROR \
337 : (::GetLastError())
338 : #elif defined(__native_client__) && __native_client__
339 : #define LOG_ERR_EX(sev, err) \
340 : LOG(sev)
341 : #define LOG_ERR(sev) \
342 : LOG(sev)
343 : #define LAST_SYSTEM_ERROR \
344 : (0)
345 : #elif defined(WEBRTC_POSIX)
346 : #define LOG_ERR_EX(sev, err) \
347 : LOG_ERRNO_EX(sev, err)
348 : #define LOG_ERR(sev) \
349 : LOG_ERRNO(sev)
350 : #define LAST_SYSTEM_ERROR \
351 : (errno)
352 : #endif // WEBRTC_WIN
353 :
354 : #define LOG_TAG(sev, tag) \
355 : LOG_SEVERITY_PRECONDITION(sev) \
356 : rtc::LogMessage(NULL, 0, sev, tag).stream()
357 :
358 : #define PLOG(sev, err) \
359 : LOG_ERR_EX(sev, err)
360 :
361 : // TODO(?): Add an "assert" wrapper that logs in the same manner.
362 :
363 : #endif // LOG
364 :
365 : } // namespace rtc
366 :
367 : #endif // WEBRTC_BASE_LOGGING_H_
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