1// Copyright (c) 1999, Google Inc.
2// All rights reserved.
3//
4// Redistribution and use in source and binary forms, with or without
5// modification, are permitted provided that the following conditions are
6// met:
7//
8// * Redistributions of source code must retain the above copyright
9// notice, this list of conditions and the following disclaimer.
10// * Redistributions in binary form must reproduce the above
11// copyright notice, this list of conditions and the following disclaimer
12// in the documentation and/or other materials provided with the
13// distribution.
14// * Neither the name of Google Inc. nor the names of its
15// contributors may be used to endorse or promote products derived from
16// this software without specific prior written permission.
17//
18// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29//
30// Author: Ray Sidney
31//
32// This file contains #include information about logging-related stuff.
33// Pretty much everybody needs to #include this file so that they can
34// log various happenings.
35//
36#ifndef _LOGGING_H_
37#define _LOGGING_H_
38
39#include <errno.h>
40#include <string.h>
41#include <time.h>
42#include <iosfwd>
43#include <ostream>
44#include <sstream>
45#include <string>
46#if 1
47# include <unistd.h>
48#endif
49#include <vector>
50
51// Annoying stuff for windows -- makes sure clients can import these functions
52#ifndef GOOGLE_GLOG_DLL_DECL
53# if defined(_WIN32) && !defined(__CYGWIN__)
54# define GOOGLE_GLOG_DLL_DECL __declspec(dllimport)
55# else
56# define GOOGLE_GLOG_DLL_DECL
57# endif
58#endif
59#if defined(_MSC_VER)
60#define GLOG_MSVC_PUSH_DISABLE_WARNING(n) __pragma(warning(push)) \
61 __pragma(warning(disable:n))
62#define GLOG_MSVC_POP_WARNING() __pragma(warning(pop))
63#else
64#define GLOG_MSVC_PUSH_DISABLE_WARNING(n)
65#define GLOG_MSVC_POP_WARNING()
66#endif
67
68// We care a lot about number of bits things take up. Unfortunately,
69// systems define their bit-specific ints in a lot of different ways.
70// We use our own way, and have a typedef to get there.
71// Note: these commands below may look like "#if 1" or "#if 0", but
72// that's because they were constructed that way at ./configure time.
73// Look at logging.h.in to see how they're calculated (based on your config).
74#if 1
75#include <stdint.h> // the normal place uint16_t is defined
76#endif
77#if 1
78#include <sys/types.h> // the normal place u_int16_t is defined
79#endif
80#if 1
81#include <inttypes.h> // a third place for uint16_t or u_int16_t
82#endif
83
84#if 1
85#include <gflags/gflags.h>
86#endif
87
88namespace google {
89
90#if 1 // the C99 format
91typedef int32_t int32;
92typedef uint32_t uint32;
93typedef int64_t int64;
94typedef uint64_t uint64;
95#elif 1 // the BSD format
96typedef int32_t int32;
97typedef u_int32_t uint32;
98typedef int64_t int64;
99typedef u_int64_t uint64;
100#elif 0 // the windows (vc7) format
101typedef __int32 int32;
102typedef unsigned __int32 uint32;
103typedef __int64 int64;
104typedef unsigned __int64 uint64;
105#else
106#error Do not know how to define a 32-bit integer quantity on your system
107#endif
108
109}
110
111// The global value of GOOGLE_STRIP_LOG. All the messages logged to
112// LOG(XXX) with severity less than GOOGLE_STRIP_LOG will not be displayed.
113// If it can be determined at compile time that the message will not be
114// printed, the statement will be compiled out.
115//
116// Example: to strip out all INFO and WARNING messages, use the value
117// of 2 below. To make an exception for WARNING messages from a single
118// file, add "#define GOOGLE_STRIP_LOG 1" to that file _before_ including
119// base/logging.h
120#ifndef GOOGLE_STRIP_LOG
121#define GOOGLE_STRIP_LOG 0
122#endif
123
124// GCC can be told that a certain branch is not likely to be taken (for
125// instance, a CHECK failure), and use that information in static analysis.
126// Giving it this information can help it optimize for the common case in
127// the absence of better information (ie. -fprofile-arcs).
128//
129#ifndef GOOGLE_PREDICT_BRANCH_NOT_TAKEN
130#if 1
131#define GOOGLE_PREDICT_BRANCH_NOT_TAKEN(x) (__builtin_expect(x, 0))
132#define GOOGLE_PREDICT_FALSE(x) (__builtin_expect(x, 0))
133#define GOOGLE_PREDICT_TRUE(x) (__builtin_expect(!!(x), 1))
134#else
135#define GOOGLE_PREDICT_BRANCH_NOT_TAKEN(x) x
136#define GOOGLE_PREDICT_FALSE(x) x
137#define GOOGLE_PREDICT_TRUE(x) x
138#endif
139#endif
140
141// Make a bunch of macros for logging. The way to log things is to stream
142// things to LOG(<a particular severity level>). E.g.,
143//
144// LOG(INFO) << "Found " << num_cookies << " cookies";
145//
146// You can capture log messages in a string, rather than reporting them
147// immediately:
148//
149// vector<string> errors;
150// LOG_STRING(ERROR, &errors) << "Couldn't parse cookie #" << cookie_num;
151//
152// This pushes back the new error onto 'errors'; if given a NULL pointer,
153// it reports the error via LOG(ERROR).
154//
155// You can also do conditional logging:
156//
157// LOG_IF(INFO, num_cookies > 10) << "Got lots of cookies";
158//
159// You can also do occasional logging (log every n'th occurrence of an
160// event):
161//
162// LOG_EVERY_N(INFO, 10) << "Got the " << google::COUNTER << "th cookie";
163//
164// The above will cause log messages to be output on the 1st, 11th, 21st, ...
165// times it is executed. Note that the special google::COUNTER value is used
166// to identify which repetition is happening.
167//
168// You can also do occasional conditional logging (log every n'th
169// occurrence of an event, when condition is satisfied):
170//
171// LOG_IF_EVERY_N(INFO, (size > 1024), 10) << "Got the " << google::COUNTER
172// << "th big cookie";
173//
174// You can log messages the first N times your code executes a line. E.g.
175//
176// LOG_FIRST_N(INFO, 20) << "Got the " << google::COUNTER << "th cookie";
177//
178// Outputs log messages for the first 20 times it is executed.
179//
180// Analogous SYSLOG, SYSLOG_IF, and SYSLOG_EVERY_N macros are available.
181// These log to syslog as well as to the normal logs. If you use these at
182// all, you need to be aware that syslog can drastically reduce performance,
183// especially if it is configured for remote logging! Don't use these
184// unless you fully understand this and have a concrete need to use them.
185// Even then, try to minimize your use of them.
186//
187// There are also "debug mode" logging macros like the ones above:
188//
189// DLOG(INFO) << "Found cookies";
190//
191// DLOG_IF(INFO, num_cookies > 10) << "Got lots of cookies";
192//
193// DLOG_EVERY_N(INFO, 10) << "Got the " << google::COUNTER << "th cookie";
194//
195// All "debug mode" logging is compiled away to nothing for non-debug mode
196// compiles.
197//
198// We also have
199//
200// LOG_ASSERT(assertion);
201// DLOG_ASSERT(assertion);
202//
203// which is syntactic sugar for {,D}LOG_IF(FATAL, assert fails) << assertion;
204//
205// There are "verbose level" logging macros. They look like
206//
207// VLOG(1) << "I'm printed when you run the program with --v=1 or more";
208// VLOG(2) << "I'm printed when you run the program with --v=2 or more";
209//
210// These always log at the INFO log level (when they log at all).
211// The verbose logging can also be turned on module-by-module. For instance,
212// --vmodule=mapreduce=2,file=1,gfs*=3 --v=0
213// will cause:
214// a. VLOG(2) and lower messages to be printed from mapreduce.{h,cc}
215// b. VLOG(1) and lower messages to be printed from file.{h,cc}
216// c. VLOG(3) and lower messages to be printed from files prefixed with "gfs"
217// d. VLOG(0) and lower messages to be printed from elsewhere
218//
219// The wildcarding functionality shown by (c) supports both '*' (match
220// 0 or more characters) and '?' (match any single character) wildcards.
221//
222// There's also VLOG_IS_ON(n) "verbose level" condition macro. To be used as
223//
224// if (VLOG_IS_ON(2)) {
225// // do some logging preparation and logging
226// // that can't be accomplished with just VLOG(2) << ...;
227// }
228//
229// There are also VLOG_IF, VLOG_EVERY_N and VLOG_IF_EVERY_N "verbose level"
230// condition macros for sample cases, when some extra computation and
231// preparation for logs is not needed.
232// VLOG_IF(1, (size > 1024))
233// << "I'm printed when size is more than 1024 and when you run the "
234// "program with --v=1 or more";
235// VLOG_EVERY_N(1, 10)
236// << "I'm printed every 10th occurrence, and when you run the program "
237// "with --v=1 or more. Present occurence is " << google::COUNTER;
238// VLOG_IF_EVERY_N(1, (size > 1024), 10)
239// << "I'm printed on every 10th occurence of case when size is more "
240// " than 1024, when you run the program with --v=1 or more. ";
241// "Present occurence is " << google::COUNTER;
242//
243// The supported severity levels for macros that allow you to specify one
244// are (in increasing order of severity) INFO, WARNING, ERROR, and FATAL.
245// Note that messages of a given severity are logged not only in the
246// logfile for that severity, but also in all logfiles of lower severity.
247// E.g., a message of severity FATAL will be logged to the logfiles of
248// severity FATAL, ERROR, WARNING, and INFO.
249//
250// There is also the special severity of DFATAL, which logs FATAL in
251// debug mode, ERROR in normal mode.
252//
253// Very important: logging a message at the FATAL severity level causes
254// the program to terminate (after the message is logged).
255//
256// Unless otherwise specified, logs will be written to the filename
257// "<program name>.<hostname>.<user name>.log.<severity level>.", followed
258// by the date, time, and pid (you can't prevent the date, time, and pid
259// from being in the filename).
260//
261// The logging code takes two flags:
262// --v=# set the verbose level
263// --logtostderr log all the messages to stderr instead of to logfiles
264
265// LOG LINE PREFIX FORMAT
266//
267// Log lines have this form:
268//
269// Lmmdd hh:mm:ss.uuuuuu threadid file:line] msg...
270//
271// where the fields are defined as follows:
272//
273// L A single character, representing the log level
274// (eg 'I' for INFO)
275// mm The month (zero padded; ie May is '05')
276// dd The day (zero padded)
277// hh:mm:ss.uuuuuu Time in hours, minutes and fractional seconds
278// threadid The space-padded thread ID as returned by GetTID()
279// (this matches the PID on Linux)
280// file The file name
281// line The line number
282// msg The user-supplied message
283//
284// Example:
285//
286// I1103 11:57:31.739339 24395 google.cc:2341] Command line: ./some_prog
287// I1103 11:57:31.739403 24395 google.cc:2342] Process id 24395
288//
289// NOTE: although the microseconds are useful for comparing events on
290// a single machine, clocks on different machines may not be well
291// synchronized. Hence, use caution when comparing the low bits of
292// timestamps from different machines.
293
294#ifndef DECLARE_VARIABLE
295#define MUST_UNDEF_GFLAGS_DECLARE_MACROS
296#define DECLARE_VARIABLE(type, shorttype, name, tn) \
297 namespace fL##shorttype { \
298 extern GOOGLE_GLOG_DLL_DECL type FLAGS_##name; \
299 } \
300 using fL##shorttype::FLAGS_##name
301
302// bool specialization
303#define DECLARE_bool(name) \
304 DECLARE_VARIABLE(bool, B, name, bool)
305
306// int32 specialization
307#define DECLARE_int32(name) \
308 DECLARE_VARIABLE(google::int32, I, name, int32)
309
310// Special case for string, because we have to specify the namespace
311// std::string, which doesn't play nicely with our FLAG__namespace hackery.
312#define DECLARE_string(name) \
313 namespace fLS { \
314 extern GOOGLE_GLOG_DLL_DECL std::string& FLAGS_##name; \
315 } \
316 using fLS::FLAGS_##name
317#endif
318
319// Set whether log messages go to stderr instead of logfiles
320DECLARE_bool(logtostderr);
321
322// Set whether log messages go to stderr in addition to logfiles.
323DECLARE_bool(alsologtostderr);
324
325// Set color messages logged to stderr (if supported by terminal).
326DECLARE_bool(colorlogtostderr);
327
328// Log messages at a level >= this flag are automatically sent to
329// stderr in addition to log files.
330DECLARE_int32(stderrthreshold);
331
332// Set whether the log prefix should be prepended to each line of output.
333DECLARE_bool(log_prefix);
334
335// Log messages at a level <= this flag are buffered.
336// Log messages at a higher level are flushed immediately.
337DECLARE_int32(logbuflevel);
338
339// Sets the maximum number of seconds which logs may be buffered for.
340DECLARE_int32(logbufsecs);
341
342// Log suppression level: messages logged at a lower level than this
343// are suppressed.
344DECLARE_int32(minloglevel);
345
346// If specified, logfiles are written into this directory instead of the
347// default logging directory.
348DECLARE_string(log_dir);
349
350// Sets the path of the directory into which to put additional links
351// to the log files.
352DECLARE_string(log_link);
353
354DECLARE_int32(v); // in vlog_is_on.cc
355
356// Sets the maximum log file size (in MB).
357DECLARE_int32(max_log_size);
358
359// Sets whether to avoid logging to the disk if the disk is full.
360DECLARE_bool(stop_logging_if_full_disk);
361
362#ifdef MUST_UNDEF_GFLAGS_DECLARE_MACROS
363#undef MUST_UNDEF_GFLAGS_DECLARE_MACROS
364#undef DECLARE_VARIABLE
365#undef DECLARE_bool
366#undef DECLARE_int32
367#undef DECLARE_string
368#endif
369
370// Log messages below the GOOGLE_STRIP_LOG level will be compiled away for
371// security reasons. See LOG(severtiy) below.
372
373// A few definitions of macros that don't generate much code. Since
374// LOG(INFO) and its ilk are used all over our code, it's
375// better to have compact code for these operations.
376
377#if GOOGLE_STRIP_LOG == 0
378#define COMPACT_GOOGLE_LOG_INFO google::LogMessage( \
379 __FILE__, __LINE__)
380#define LOG_TO_STRING_INFO(message) google::LogMessage( \
381 __FILE__, __LINE__, google::GLOG_INFO, message)
382#else
383#define COMPACT_GOOGLE_LOG_INFO google::NullStream()
384#define LOG_TO_STRING_INFO(message) google::NullStream()
385#endif
386
387#if GOOGLE_STRIP_LOG <= 1
388#define COMPACT_GOOGLE_LOG_WARNING google::LogMessage( \
389 __FILE__, __LINE__, google::GLOG_WARNING)
390#define LOG_TO_STRING_WARNING(message) google::LogMessage( \
391 __FILE__, __LINE__, google::GLOG_WARNING, message)
392#else
393#define COMPACT_GOOGLE_LOG_WARNING google::NullStream()
394#define LOG_TO_STRING_WARNING(message) google::NullStream()
395#endif
396
397#if GOOGLE_STRIP_LOG <= 2
398#define COMPACT_GOOGLE_LOG_ERROR google::LogMessage( \
399 __FILE__, __LINE__, google::GLOG_ERROR)
400#define LOG_TO_STRING_ERROR(message) google::LogMessage( \
401 __FILE__, __LINE__, google::GLOG_ERROR, message)
402#else
403#define COMPACT_GOOGLE_LOG_ERROR google::NullStream()
404#define LOG_TO_STRING_ERROR(message) google::NullStream()
405#endif
406
407#if GOOGLE_STRIP_LOG <= 3
408#define COMPACT_GOOGLE_LOG_FATAL google::LogMessageFatal( \
409 __FILE__, __LINE__)
410#define LOG_TO_STRING_FATAL(message) google::LogMessage( \
411 __FILE__, __LINE__, google::GLOG_FATAL, message)
412#else
413#define COMPACT_GOOGLE_LOG_FATAL google::NullStreamFatal()
414#define LOG_TO_STRING_FATAL(message) google::NullStreamFatal()
415#endif
416
417// For DFATAL, we want to use LogMessage (as opposed to
418// LogMessageFatal), to be consistent with the original behavior.
419#ifdef NDEBUG
420#define COMPACT_GOOGLE_LOG_DFATAL COMPACT_GOOGLE_LOG_ERROR
421#elif GOOGLE_STRIP_LOG <= 3
422#define COMPACT_GOOGLE_LOG_DFATAL google::LogMessage( \
423 __FILE__, __LINE__, google::GLOG_FATAL)
424#else
425#define COMPACT_GOOGLE_LOG_DFATAL google::NullStreamFatal()
426#endif
427
428#define GOOGLE_LOG_INFO(counter) google::LogMessage(__FILE__, __LINE__, google::GLOG_INFO, counter, &google::LogMessage::SendToLog)
429#define SYSLOG_INFO(counter) \
430 google::LogMessage(__FILE__, __LINE__, google::GLOG_INFO, counter, \
431 &google::LogMessage::SendToSyslogAndLog)
432#define GOOGLE_LOG_WARNING(counter) \
433 google::LogMessage(__FILE__, __LINE__, google::GLOG_WARNING, counter, \
434 &google::LogMessage::SendToLog)
435#define SYSLOG_WARNING(counter) \
436 google::LogMessage(__FILE__, __LINE__, google::GLOG_WARNING, counter, \
437 &google::LogMessage::SendToSyslogAndLog)
438#define GOOGLE_LOG_ERROR(counter) \
439 google::LogMessage(__FILE__, __LINE__, google::GLOG_ERROR, counter, \
440 &google::LogMessage::SendToLog)
441#define SYSLOG_ERROR(counter) \
442 google::LogMessage(__FILE__, __LINE__, google::GLOG_ERROR, counter, \
443 &google::LogMessage::SendToSyslogAndLog)
444#define GOOGLE_LOG_FATAL(counter) \
445 google::LogMessage(__FILE__, __LINE__, google::GLOG_FATAL, counter, \
446 &google::LogMessage::SendToLog)
447#define SYSLOG_FATAL(counter) \
448 google::LogMessage(__FILE__, __LINE__, google::GLOG_FATAL, counter, \
449 &google::LogMessage::SendToSyslogAndLog)
450#define GOOGLE_LOG_DFATAL(counter) \
451 google::LogMessage(__FILE__, __LINE__, google::DFATAL_LEVEL, counter, \
452 &google::LogMessage::SendToLog)
453#define SYSLOG_DFATAL(counter) \
454 google::LogMessage(__FILE__, __LINE__, google::DFATAL_LEVEL, counter, \
455 &google::LogMessage::SendToSyslogAndLog)
456
457#if defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__) || defined(__CYGWIN32__)
458// A very useful logging macro to log windows errors:
459#define LOG_SYSRESULT(result) \
460 if (FAILED(HRESULT_FROM_WIN32(result))) { \
461 LPSTR message = NULL; \
462 LPSTR msg = reinterpret_cast<LPSTR>(&message); \
463 DWORD message_length = FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | \
464 FORMAT_MESSAGE_FROM_SYSTEM, \
465 0, result, 0, msg, 100, NULL); \
466 if (message_length > 0) { \
467 google::LogMessage(__FILE__, __LINE__, google::GLOG_ERROR, 0, \
468 &google::LogMessage::SendToLog).stream() \
469 << reinterpret_cast<const char*>(message); \
470 LocalFree(message); \
471 } \
472 }
473#endif
474
475// We use the preprocessor's merging operator, "##", so that, e.g.,
476// LOG(INFO) becomes the token GOOGLE_LOG_INFO. There's some funny
477// subtle difference between ostream member streaming functions (e.g.,
478// ostream::operator<<(int) and ostream non-member streaming functions
479// (e.g., ::operator<<(ostream&, string&): it turns out that it's
480// impossible to stream something like a string directly to an unnamed
481// ostream. We employ a neat hack by calling the stream() member
482// function of LogMessage which seems to avoid the problem.
483#define LOG(severity) COMPACT_GOOGLE_LOG_ ## severity.stream()
484#define SYSLOG(severity) SYSLOG_ ## severity(0).stream()
485
486namespace google {
487
488// They need the definitions of integer types.
489#include "glog/log_severity.h"
490#include "glog/vlog_is_on.h"
491
492// Initialize google's logging library. You will see the program name
493// specified by argv0 in log outputs.
494GOOGLE_GLOG_DLL_DECL void InitGoogleLogging(const char* argv0);
495
496// Shutdown google's logging library.
497GOOGLE_GLOG_DLL_DECL void ShutdownGoogleLogging();
498
499// Install a function which will be called after LOG(FATAL).
500GOOGLE_GLOG_DLL_DECL void InstallFailureFunction(void (*fail_func)());
501
502class LogSink; // defined below
503
504// If a non-NULL sink pointer is given, we push this message to that sink.
505// For LOG_TO_SINK we then do normal LOG(severity) logging as well.
506// This is useful for capturing messages and passing/storing them
507// somewhere more specific than the global log of the process.
508// Argument types:
509// LogSink* sink;
510// LogSeverity severity;
511// The cast is to disambiguate NULL arguments.
512#define LOG_TO_SINK(sink, severity) \
513 google::LogMessage( \
514 __FILE__, __LINE__, \
515 google::GLOG_ ## severity, \
516 static_cast<google::LogSink*>(sink), true).stream()
517#define LOG_TO_SINK_BUT_NOT_TO_LOGFILE(sink, severity) \
518 google::LogMessage( \
519 __FILE__, __LINE__, \
520 google::GLOG_ ## severity, \
521 static_cast<google::LogSink*>(sink), false).stream()
522
523// If a non-NULL string pointer is given, we write this message to that string.
524// We then do normal LOG(severity) logging as well.
525// This is useful for capturing messages and storing them somewhere more
526// specific than the global log of the process.
527// Argument types:
528// string* message;
529// LogSeverity severity;
530// The cast is to disambiguate NULL arguments.
531// NOTE: LOG(severity) expands to LogMessage().stream() for the specified
532// severity.
533#define LOG_TO_STRING(severity, message) \
534 LOG_TO_STRING_##severity(static_cast<string*>(message)).stream()
535
536// If a non-NULL pointer is given, we push the message onto the end
537// of a vector of strings; otherwise, we report it with LOG(severity).
538// This is handy for capturing messages and perhaps passing them back
539// to the caller, rather than reporting them immediately.
540// Argument types:
541// LogSeverity severity;
542// vector<string> *outvec;
543// The cast is to disambiguate NULL arguments.
544#define LOG_STRING(severity, outvec) \
545 LOG_TO_STRING_##severity(static_cast<vector<string>*>(outvec)).stream()
546
547#define LOG_IF(severity, condition) \
548 !(condition) ? (void) 0 : google::LogMessageVoidify() & LOG(severity)
549#define SYSLOG_IF(severity, condition) \
550 !(condition) ? (void) 0 : google::LogMessageVoidify() & SYSLOG(severity)
551
552#define LOG_ASSERT(condition) \
553 LOG_IF(FATAL, !(condition)) << "Assert failed: " #condition
554#define SYSLOG_ASSERT(condition) \
555 SYSLOG_IF(FATAL, !(condition)) << "Assert failed: " #condition
556
557// CHECK dies with a fatal error if condition is not true. It is *not*
558// controlled by NDEBUG, so the check will be executed regardless of
559// compilation mode. Therefore, it is safe to do things like:
560// CHECK(fp->Write(x) == 4)
561#define CHECK(condition) \
562 LOG_IF(FATAL, GOOGLE_PREDICT_BRANCH_NOT_TAKEN(!(condition))) \
563 << "Check failed: " #condition " "
564
565// A container for a string pointer which can be evaluated to a bool -
566// true iff the pointer is NULL.
567struct CheckOpString {
568 CheckOpString(std::string* str) : str_(str) { }
569 // No destructor: if str_ is non-NULL, we're about to LOG(FATAL),
570 // so there's no point in cleaning up str_.
571 operator bool() const {
572 return GOOGLE_PREDICT_BRANCH_NOT_TAKEN(str_ != NULL);
573 }
574 std::string* str_;
575};
576
577// Function is overloaded for integral types to allow static const
578// integrals declared in classes and not defined to be used as arguments to
579// CHECK* macros. It's not encouraged though.
580template <class T>
581inline const T& GetReferenceableValue(const T& t) { return t; }
582inline char GetReferenceableValue(char t) { return t; }
583inline unsigned char GetReferenceableValue(unsigned char t) { return t; }
584inline signed char GetReferenceableValue(signed char t) { return t; }
585inline short GetReferenceableValue(short t) { return t; }
586inline unsigned short GetReferenceableValue(unsigned short t) { return t; }
587inline int GetReferenceableValue(int t) { return t; }
588inline unsigned int GetReferenceableValue(unsigned int t) { return t; }
589inline long GetReferenceableValue(long t) { return t; }
590inline unsigned long GetReferenceableValue(unsigned long t) { return t; }
591inline long long GetReferenceableValue(long long t) { return t; }
592inline unsigned long long GetReferenceableValue(unsigned long long t) {
593 return t;
594}
595
596// This is a dummy class to define the following operator.
597struct DummyClassToDefineOperator {};
598
599}
600
601// Define global operator<< to declare using ::operator<<.
602// This declaration will allow use to use CHECK macros for user
603// defined classes which have operator<< (e.g., stl_logging.h).
604inline std::ostream& operator<<(
605 std::ostream& out, const google::DummyClassToDefineOperator&) {
606 return out;
607}
608
609namespace google {
610
611// This formats a value for a failing CHECK_XX statement. Ordinarily,
612// it uses the definition for operator<<, with a few special cases below.
613template <typename T>
614inline void MakeCheckOpValueString(std::ostream* os, const T& v) {
615 (*os) << v;
616}
617
618// Overrides for char types provide readable values for unprintable
619// characters.
620template <> GOOGLE_GLOG_DLL_DECL
621void MakeCheckOpValueString(std::ostream* os, const char& v);
622template <> GOOGLE_GLOG_DLL_DECL
623void MakeCheckOpValueString(std::ostream* os, const signed char& v);
624template <> GOOGLE_GLOG_DLL_DECL
625void MakeCheckOpValueString(std::ostream* os, const unsigned char& v);
626
627// Build the error message string. Specify no inlining for code size.
628template <typename T1, typename T2>
629std::string* MakeCheckOpString(const T1& v1, const T2& v2, const char* exprtext)
630 __attribute__ ((noinline));
631
632namespace base {
633namespace internal {
634
635// If "s" is less than base_logging::INFO, returns base_logging::INFO.
636// If "s" is greater than base_logging::FATAL, returns
637// base_logging::ERROR. Otherwise, returns "s".
638LogSeverity NormalizeSeverity(LogSeverity s);
639
640} // namespace internal
641
642// A helper class for formatting "expr (V1 vs. V2)" in a CHECK_XX
643// statement. See MakeCheckOpString for sample usage. Other
644// approaches were considered: use of a template method (e.g.,
645// base::BuildCheckOpString(exprtext, base::Print<T1>, &v1,
646// base::Print<T2>, &v2), however this approach has complications
647// related to volatile arguments and function-pointer arguments).
648class GOOGLE_GLOG_DLL_DECL CheckOpMessageBuilder {
649 public:
650 // Inserts "exprtext" and " (" to the stream.
651 explicit CheckOpMessageBuilder(const char *exprtext);
652 // Deletes "stream_".
653 ~CheckOpMessageBuilder();
654 // For inserting the first variable.
655 std::ostream* ForVar1() { return stream_; }
656 // For inserting the second variable (adds an intermediate " vs. ").
657 std::ostream* ForVar2();
658 // Get the result (inserts the closing ")").
659 std::string* NewString();
660
661 private:
662 std::ostringstream *stream_;
663};
664
665} // namespace base
666
667template <typename T1, typename T2>
668std::string* MakeCheckOpString(const T1& v1, const T2& v2, const char* exprtext) {
669 base::CheckOpMessageBuilder comb(exprtext);
670 MakeCheckOpValueString(comb.ForVar1(), v1);
671 MakeCheckOpValueString(comb.ForVar2(), v2);
672 return comb.NewString();
673}
674
675// Helper functions for CHECK_OP macro.
676// The (int, int) specialization works around the issue that the compiler
677// will not instantiate the template version of the function on values of
678// unnamed enum type - see comment below.
679#define DEFINE_CHECK_OP_IMPL(name, op) \
680 template <typename T1, typename T2> \
681 inline std::string* name##Impl(const T1& v1, const T2& v2, \
682 const char* exprtext) { \
683 if (GOOGLE_PREDICT_TRUE(v1 op v2)) return NULL; \
684 else return MakeCheckOpString(v1, v2, exprtext); \
685 } \
686 inline std::string* name##Impl(int v1, int v2, const char* exprtext) { \
687 return name##Impl<int, int>(v1, v2, exprtext); \
688 }
689
690// We use the full name Check_EQ, Check_NE, etc. in case the file including
691// base/logging.h provides its own #defines for the simpler names EQ, NE, etc.
692// This happens if, for example, those are used as token names in a
693// yacc grammar.
694DEFINE_CHECK_OP_IMPL(Check_EQ, ==) // Compilation error with CHECK_EQ(NULL, x)?
695DEFINE_CHECK_OP_IMPL(Check_NE, !=) // Use CHECK(x == NULL) instead.
696DEFINE_CHECK_OP_IMPL(Check_LE, <=)
697DEFINE_CHECK_OP_IMPL(Check_LT, < )
698DEFINE_CHECK_OP_IMPL(Check_GE, >=)
699DEFINE_CHECK_OP_IMPL(Check_GT, > )
700#undef DEFINE_CHECK_OP_IMPL
701
702// Helper macro for binary operators.
703// Don't use this macro directly in your code, use CHECK_EQ et al below.
704
705#if defined(STATIC_ANALYSIS)
706// Only for static analysis tool to know that it is equivalent to assert
707#define CHECK_OP_LOG(name, op, val1, val2, log) CHECK((val1) op (val2))
708#elif !defined(NDEBUG)
709// In debug mode, avoid constructing CheckOpStrings if possible,
710// to reduce the overhead of CHECK statments by 2x.
711// Real DCHECK-heavy tests have seen 1.5x speedups.
712
713// The meaning of "string" might be different between now and
714// when this macro gets invoked (e.g., if someone is experimenting
715// with other string implementations that get defined after this
716// file is included). Save the current meaning now and use it
717// in the macro.
718typedef std::string _Check_string;
719#define CHECK_OP_LOG(name, op, val1, val2, log) \
720 while (google::_Check_string* _result = \
721 google::Check##name##Impl( \
722 google::GetReferenceableValue(val1), \
723 google::GetReferenceableValue(val2), \
724 #val1 " " #op " " #val2)) \
725 log(__FILE__, __LINE__, \
726 google::CheckOpString(_result)).stream()
727#else
728// In optimized mode, use CheckOpString to hint to compiler that
729// the while condition is unlikely.
730#define CHECK_OP_LOG(name, op, val1, val2, log) \
731 while (google::CheckOpString _result = \
732 google::Check##name##Impl( \
733 google::GetReferenceableValue(val1), \
734 google::GetReferenceableValue(val2), \
735 #val1 " " #op " " #val2)) \
736 log(__FILE__, __LINE__, _result).stream()
737#endif // STATIC_ANALYSIS, !NDEBUG
738
739#if GOOGLE_STRIP_LOG <= 3
740#define CHECK_OP(name, op, val1, val2) \
741 CHECK_OP_LOG(name, op, val1, val2, google::LogMessageFatal)
742#else
743#define CHECK_OP(name, op, val1, val2) \
744 CHECK_OP_LOG(name, op, val1, val2, google::NullStreamFatal)
745#endif // STRIP_LOG <= 3
746
747// Equality/Inequality checks - compare two values, and log a FATAL message
748// including the two values when the result is not as expected. The values
749// must have operator<<(ostream, ...) defined.
750//
751// You may append to the error message like so:
752// CHECK_NE(1, 2) << ": The world must be ending!";
753//
754// We are very careful to ensure that each argument is evaluated exactly
755// once, and that anything which is legal to pass as a function argument is
756// legal here. In particular, the arguments may be temporary expressions
757// which will end up being destroyed at the end of the apparent statement,
758// for example:
759// CHECK_EQ(string("abc")[1], 'b');
760//
761// WARNING: These don't compile correctly if one of the arguments is a pointer
762// and the other is NULL. To work around this, simply static_cast NULL to the
763// type of the desired pointer.
764
765#define CHECK_EQ(val1, val2) CHECK_OP(_EQ, ==, val1, val2)
766#define CHECK_NE(val1, val2) CHECK_OP(_NE, !=, val1, val2)
767#define CHECK_LE(val1, val2) CHECK_OP(_LE, <=, val1, val2)
768#define CHECK_LT(val1, val2) CHECK_OP(_LT, < , val1, val2)
769#define CHECK_GE(val1, val2) CHECK_OP(_GE, >=, val1, val2)
770#define CHECK_GT(val1, val2) CHECK_OP(_GT, > , val1, val2)
771
772// Check that the input is non NULL. This very useful in constructor
773// initializer lists.
774
775#define CHECK_NOTNULL(val) \
776 google::CheckNotNull(__FILE__, __LINE__, "'" #val "' Must be non NULL", (val))
777
778// Helper functions for string comparisons.
779// To avoid bloat, the definitions are in logging.cc.
780#define DECLARE_CHECK_STROP_IMPL(func, expected) \
781 GOOGLE_GLOG_DLL_DECL std::string* Check##func##expected##Impl( \
782 const char* s1, const char* s2, const char* names);
783DECLARE_CHECK_STROP_IMPL(strcmp, true)
784DECLARE_CHECK_STROP_IMPL(strcmp, false)
785DECLARE_CHECK_STROP_IMPL(strcasecmp, true)
786DECLARE_CHECK_STROP_IMPL(strcasecmp, false)
787#undef DECLARE_CHECK_STROP_IMPL
788
789// Helper macro for string comparisons.
790// Don't use this macro directly in your code, use CHECK_STREQ et al below.
791#define CHECK_STROP(func, op, expected, s1, s2) \
792 while (google::CheckOpString _result = \
793 google::Check##func##expected##Impl((s1), (s2), \
794 #s1 " " #op " " #s2)) \
795 LOG(FATAL) << *_result.str_
796
797
798// String (char*) equality/inequality checks.
799// CASE versions are case-insensitive.
800//
801// Note that "s1" and "s2" may be temporary strings which are destroyed
802// by the compiler at the end of the current "full expression"
803// (e.g. CHECK_STREQ(Foo().c_str(), Bar().c_str())).
804
805#define CHECK_STREQ(s1, s2) CHECK_STROP(strcmp, ==, true, s1, s2)
806#define CHECK_STRNE(s1, s2) CHECK_STROP(strcmp, !=, false, s1, s2)
807#define CHECK_STRCASEEQ(s1, s2) CHECK_STROP(strcasecmp, ==, true, s1, s2)
808#define CHECK_STRCASENE(s1, s2) CHECK_STROP(strcasecmp, !=, false, s1, s2)
809
810#define CHECK_INDEX(I,A) CHECK(I < (sizeof(A)/sizeof(A[0])))
811#define CHECK_BOUND(B,A) CHECK(B <= (sizeof(A)/sizeof(A[0])))
812
813#define CHECK_DOUBLE_EQ(val1, val2) \
814 do { \
815 CHECK_LE((val1), (val2)+0.000000000000001L); \
816 CHECK_GE((val1), (val2)-0.000000000000001L); \
817 } while (0)
818
819#define CHECK_NEAR(val1, val2, margin) \
820 do { \
821 CHECK_LE((val1), (val2)+(margin)); \
822 CHECK_GE((val1), (val2)-(margin)); \
823 } while (0)
824
825// perror()..googly style!
826//
827// PLOG() and PLOG_IF() and PCHECK() behave exactly like their LOG* and
828// CHECK equivalents with the addition that they postpend a description
829// of the current state of errno to their output lines.
830
831#define PLOG(severity) GOOGLE_PLOG(severity, 0).stream()
832
833#define GOOGLE_PLOG(severity, counter) \
834 google::ErrnoLogMessage( \
835 __FILE__, __LINE__, google::GLOG_ ## severity, counter, \
836 &google::LogMessage::SendToLog)
837
838#define PLOG_IF(severity, condition) \
839 !(condition) ? (void) 0 : google::LogMessageVoidify() & PLOG(severity)
840
841// A CHECK() macro that postpends errno if the condition is false. E.g.
842//
843// if (poll(fds, nfds, timeout) == -1) { PCHECK(errno == EINTR); ... }
844#define PCHECK(condition) \
845 PLOG_IF(FATAL, GOOGLE_PREDICT_BRANCH_NOT_TAKEN(!(condition))) \
846 << "Check failed: " #condition " "
847
848// A CHECK() macro that lets you assert the success of a function that
849// returns -1 and sets errno in case of an error. E.g.
850//
851// CHECK_ERR(mkdir(path, 0700));
852//
853// or
854//
855// int fd = open(filename, flags); CHECK_ERR(fd) << ": open " << filename;
856#define CHECK_ERR(invocation) \
857PLOG_IF(FATAL, GOOGLE_PREDICT_BRANCH_NOT_TAKEN((invocation) == -1)) \
858 << #invocation
859
860// Use macro expansion to create, for each use of LOG_EVERY_N(), static
861// variables with the __LINE__ expansion as part of the variable name.
862#define LOG_EVERY_N_VARNAME(base, line) LOG_EVERY_N_VARNAME_CONCAT(base, line)
863#define LOG_EVERY_N_VARNAME_CONCAT(base, line) base ## line
864
865#define LOG_OCCURRENCES LOG_EVERY_N_VARNAME(occurrences_, __LINE__)
866#define LOG_OCCURRENCES_MOD_N LOG_EVERY_N_VARNAME(occurrences_mod_n_, __LINE__)
867
868#define SOME_KIND_OF_LOG_EVERY_N(severity, n, what_to_do) \
869 static int LOG_OCCURRENCES = 0, LOG_OCCURRENCES_MOD_N = 0; \
870 ++LOG_OCCURRENCES; \
871 if (++LOG_OCCURRENCES_MOD_N > n) LOG_OCCURRENCES_MOD_N -= n; \
872 if (LOG_OCCURRENCES_MOD_N == 1) \
873 google::LogMessage( \
874 __FILE__, __LINE__, google::GLOG_ ## severity, LOG_OCCURRENCES, \
875 &what_to_do).stream()
876
877#define SOME_KIND_OF_LOG_IF_EVERY_N(severity, condition, n, what_to_do) \
878 static int LOG_OCCURRENCES = 0, LOG_OCCURRENCES_MOD_N = 0; \
879 ++LOG_OCCURRENCES; \
880 if (condition && \
881 ((LOG_OCCURRENCES_MOD_N=(LOG_OCCURRENCES_MOD_N + 1) % n) == (1 % n))) \
882 google::LogMessage( \
883 __FILE__, __LINE__, google::GLOG_ ## severity, LOG_OCCURRENCES, \
884 &what_to_do).stream()
885
886#define SOME_KIND_OF_PLOG_EVERY_N(severity, n, what_to_do) \
887 static int LOG_OCCURRENCES = 0, LOG_OCCURRENCES_MOD_N = 0; \
888 ++LOG_OCCURRENCES; \
889 if (++LOG_OCCURRENCES_MOD_N > n) LOG_OCCURRENCES_MOD_N -= n; \
890 if (LOG_OCCURRENCES_MOD_N == 1) \
891 google::ErrnoLogMessage( \
892 __FILE__, __LINE__, google::GLOG_ ## severity, LOG_OCCURRENCES, \
893 &what_to_do).stream()
894
895#define SOME_KIND_OF_LOG_FIRST_N(severity, n, what_to_do) \
896 static int LOG_OCCURRENCES = 0; \
897 if (LOG_OCCURRENCES <= n) \
898 ++LOG_OCCURRENCES; \
899 if (LOG_OCCURRENCES <= n) \
900 google::LogMessage( \
901 __FILE__, __LINE__, google::GLOG_ ## severity, LOG_OCCURRENCES, \
902 &what_to_do).stream()
903
904namespace glog_internal_namespace_ {
905template <bool>
906struct CompileAssert {
907};
908struct CrashReason;
909} // namespace glog_internal_namespace_
910
911#define GOOGLE_GLOG_COMPILE_ASSERT(expr, msg) \
912 typedef google::glog_internal_namespace_::CompileAssert<(bool(expr))> msg[bool(expr) ? 1 : -1]
913
914#define LOG_EVERY_N(severity, n) \
915 GOOGLE_GLOG_COMPILE_ASSERT(google::GLOG_ ## severity < \
916 google::NUM_SEVERITIES, \
917 INVALID_REQUESTED_LOG_SEVERITY); \
918 SOME_KIND_OF_LOG_EVERY_N(severity, (n), google::LogMessage::SendToLog)
919
920#define SYSLOG_EVERY_N(severity, n) \
921 SOME_KIND_OF_LOG_EVERY_N(severity, (n), google::LogMessage::SendToSyslogAndLog)
922
923#define PLOG_EVERY_N(severity, n) \
924 SOME_KIND_OF_PLOG_EVERY_N(severity, (n), google::LogMessage::SendToLog)
925
926#define LOG_FIRST_N(severity, n) \
927 SOME_KIND_OF_LOG_FIRST_N(severity, (n), google::LogMessage::SendToLog)
928
929#define LOG_IF_EVERY_N(severity, condition, n) \
930 SOME_KIND_OF_LOG_IF_EVERY_N(severity, (condition), (n), google::LogMessage::SendToLog)
931
932// We want the special COUNTER value available for LOG_EVERY_X()'ed messages
933enum PRIVATE_Counter {COUNTER};
934
935#ifdef GLOG_NO_ABBREVIATED_SEVERITIES
936// wingdi.h defines ERROR to be 0. When we call LOG(ERROR), it gets
937// substituted with 0, and it expands to COMPACT_GOOGLE_LOG_0. To allow us
938// to keep using this syntax, we define this macro to do the same thing
939// as COMPACT_GOOGLE_LOG_ERROR.
940#define COMPACT_GOOGLE_LOG_0 COMPACT_GOOGLE_LOG_ERROR
941#define SYSLOG_0 SYSLOG_ERROR
942#define LOG_TO_STRING_0 LOG_TO_STRING_ERROR
943// Needed for LOG_IS_ON(ERROR).
944const LogSeverity GLOG_0 = GLOG_ERROR;
945#else
946// Users may include windows.h after logging.h without
947// GLOG_NO_ABBREVIATED_SEVERITIES nor WIN32_LEAN_AND_MEAN.
948// For this case, we cannot detect if ERROR is defined before users
949// actually use ERROR. Let's make an undefined symbol to warn users.
950# define GLOG_ERROR_MSG ERROR_macro_is_defined_Define_GLOG_NO_ABBREVIATED_SEVERITIES_before_including_logging_h_See_the_document_for_detail
951# define COMPACT_GOOGLE_LOG_0 GLOG_ERROR_MSG
952# define SYSLOG_0 GLOG_ERROR_MSG
953# define LOG_TO_STRING_0 GLOG_ERROR_MSG
954# define GLOG_0 GLOG_ERROR_MSG
955#endif
956
957// Plus some debug-logging macros that get compiled to nothing for production
958
959#ifndef NDEBUG
960
961#define DLOG(severity) LOG(severity)
962#define DVLOG(verboselevel) VLOG(verboselevel)
963#define DLOG_IF(severity, condition) LOG_IF(severity, condition)
964#define DLOG_EVERY_N(severity, n) LOG_EVERY_N(severity, n)
965#define DLOG_IF_EVERY_N(severity, condition, n) \
966 LOG_IF_EVERY_N(severity, condition, n)
967#define DLOG_ASSERT(condition) LOG_ASSERT(condition)
968
969// debug-only checking. not executed in NDEBUG mode.
970#define DCHECK(condition) CHECK(condition)
971#define DCHECK_EQ(val1, val2) CHECK_EQ(val1, val2)
972#define DCHECK_NE(val1, val2) CHECK_NE(val1, val2)
973#define DCHECK_LE(val1, val2) CHECK_LE(val1, val2)
974#define DCHECK_LT(val1, val2) CHECK_LT(val1, val2)
975#define DCHECK_GE(val1, val2) CHECK_GE(val1, val2)
976#define DCHECK_GT(val1, val2) CHECK_GT(val1, val2)
977#define DCHECK_NOTNULL(val) CHECK_NOTNULL(val)
978#define DCHECK_STREQ(str1, str2) CHECK_STREQ(str1, str2)
979#define DCHECK_STRCASEEQ(str1, str2) CHECK_STRCASEEQ(str1, str2)
980#define DCHECK_STRNE(str1, str2) CHECK_STRNE(str1, str2)
981#define DCHECK_STRCASENE(str1, str2) CHECK_STRCASENE(str1, str2)
982
983#else // NDEBUG
984
985#define DLOG(severity) \
986 true ? (void) 0 : google::LogMessageVoidify() & LOG(severity)
987
988#define DVLOG(verboselevel) \
989 (true || !VLOG_IS_ON(verboselevel)) ?\
990 (void) 0 : google::LogMessageVoidify() & LOG(INFO)
991
992#define DLOG_IF(severity, condition) \
993 (true || !(condition)) ? (void) 0 : google::LogMessageVoidify() & LOG(severity)
994
995#define DLOG_EVERY_N(severity, n) \
996 true ? (void) 0 : google::LogMessageVoidify() & LOG(severity)
997
998#define DLOG_IF_EVERY_N(severity, condition, n) \
999 (true || !(condition))? (void) 0 : google::LogMessageVoidify() & LOG(severity)
1000
1001#define DLOG_ASSERT(condition) \
1002 true ? (void) 0 : LOG_ASSERT(condition)
1003
1004// MSVC warning C4127: conditional expression is constant
1005#define DCHECK(condition) \
1006 GLOG_MSVC_PUSH_DISABLE_WARNING(4127) \
1007 while (false) \
1008 GLOG_MSVC_POP_WARNING() CHECK(condition)
1009
1010#define DCHECK_EQ(val1, val2) \
1011 GLOG_MSVC_PUSH_DISABLE_WARNING(4127) \
1012 while (false) \
1013 GLOG_MSVC_POP_WARNING() CHECK_EQ(val1, val2)
1014
1015#define DCHECK_NE(val1, val2) \
1016 GLOG_MSVC_PUSH_DISABLE_WARNING(4127) \
1017 while (false) \
1018 GLOG_MSVC_POP_WARNING() CHECK_NE(val1, val2)
1019
1020#define DCHECK_LE(val1, val2) \
1021 GLOG_MSVC_PUSH_DISABLE_WARNING(4127) \
1022 while (false) \
1023 GLOG_MSVC_POP_WARNING() CHECK_LE(val1, val2)
1024
1025#define DCHECK_LT(val1, val2) \
1026 GLOG_MSVC_PUSH_DISABLE_WARNING(4127) \
1027 while (false) \
1028 GLOG_MSVC_POP_WARNING() CHECK_LT(val1, val2)
1029
1030#define DCHECK_GE(val1, val2) \
1031 GLOG_MSVC_PUSH_DISABLE_WARNING(4127) \
1032 while (false) \
1033 GLOG_MSVC_POP_WARNING() CHECK_GE(val1, val2)
1034
1035#define DCHECK_GT(val1, val2) \
1036 GLOG_MSVC_PUSH_DISABLE_WARNING(4127) \
1037 while (false) \
1038 GLOG_MSVC_POP_WARNING() CHECK_GT(val1, val2)
1039
1040// You may see warnings in release mode if you don't use the return
1041// value of DCHECK_NOTNULL. Please just use DCHECK for such cases.
1042#define DCHECK_NOTNULL(val) (val)
1043
1044#define DCHECK_STREQ(str1, str2) \
1045 GLOG_MSVC_PUSH_DISABLE_WARNING(4127) \
1046 while (false) \
1047 GLOG_MSVC_POP_WARNING() CHECK_STREQ(str1, str2)
1048
1049#define DCHECK_STRCASEEQ(str1, str2) \
1050 GLOG_MSVC_PUSH_DISABLE_WARNING(4127) \
1051 while (false) \
1052 GLOG_MSVC_POP_WARNING() CHECK_STRCASEEQ(str1, str2)
1053
1054#define DCHECK_STRNE(str1, str2) \
1055 GLOG_MSVC_PUSH_DISABLE_WARNING(4127) \
1056 while (false) \
1057 GLOG_MSVC_POP_WARNING() CHECK_STRNE(str1, str2)
1058
1059#define DCHECK_STRCASENE(str1, str2) \
1060 GLOG_MSVC_PUSH_DISABLE_WARNING(4127) \
1061 while (false) \
1062 GLOG_MSVC_POP_WARNING() CHECK_STRCASENE(str1, str2)
1063
1064#endif // NDEBUG
1065
1066// Log only in verbose mode.
1067
1068#define VLOG(verboselevel) LOG_IF(INFO, VLOG_IS_ON(verboselevel))
1069
1070#define VLOG_IF(verboselevel, condition) \
1071 LOG_IF(INFO, (condition) && VLOG_IS_ON(verboselevel))
1072
1073#define VLOG_EVERY_N(verboselevel, n) \
1074 LOG_IF_EVERY_N(INFO, VLOG_IS_ON(verboselevel), n)
1075
1076#define VLOG_IF_EVERY_N(verboselevel, condition, n) \
1077 LOG_IF_EVERY_N(INFO, (condition) && VLOG_IS_ON(verboselevel), n)
1078
1079namespace base_logging {
1080
1081// LogMessage::LogStream is a std::ostream backed by this streambuf.
1082// This class ignores overflow and leaves two bytes at the end of the
1083// buffer to allow for a '\n' and '\0'.
1084class GOOGLE_GLOG_DLL_DECL LogStreamBuf : public std::streambuf {
1085 public:
1086 // REQUIREMENTS: "len" must be >= 2 to account for the '\n' and '\n'.
1087 LogStreamBuf(char *buf, int len) {
1088 setp(buf, buf + len - 2);
1089 }
1090 // This effectively ignores overflow.
1091 virtual int_type overflow(int_type ch) {
1092 return ch;
1093 }
1094
1095 // Legacy public ostrstream method.
1096 size_t pcount() const { return pptr() - pbase(); }
1097 char* pbase() const { return std::streambuf::pbase(); }
1098};
1099
1100} // namespace base_logging
1101
1102//
1103// This class more or less represents a particular log message. You
1104// create an instance of LogMessage and then stream stuff to it.
1105// When you finish streaming to it, ~LogMessage is called and the
1106// full message gets streamed to the appropriate destination.
1107//
1108// You shouldn't actually use LogMessage's constructor to log things,
1109// though. You should use the LOG() macro (and variants thereof)
1110// above.
1111class GOOGLE_GLOG_DLL_DECL LogMessage {
1112public:
1113 enum {
1114 // Passing kNoLogPrefix for the line number disables the
1115 // log-message prefix. Useful for using the LogMessage
1116 // infrastructure as a printing utility. See also the --log_prefix
1117 // flag for controlling the log-message prefix on an
1118 // application-wide basis.
1119 kNoLogPrefix = -1
1120 };
1121
1122 // LogStream inherit from non-DLL-exported class (std::ostrstream)
1123 // and VC++ produces a warning for this situation.
1124 // However, MSDN says "C4275 can be ignored in Microsoft Visual C++
1125 // 2005 if you are deriving from a type in the Standard C++ Library"
1126 // http://msdn.microsoft.com/en-us/library/3tdb471s(VS.80).aspx
1127 // Let's just ignore the warning.
1128#ifdef _MSC_VER
1129# pragma warning(disable: 4275)
1130#endif
1131 class GOOGLE_GLOG_DLL_DECL LogStream : public std::ostream {
1132#ifdef _MSC_VER
1133# pragma warning(default: 4275)
1134#endif
1135 public:
1136 LogStream(char *buf, int len, int ctr)
1137 : std::ostream(NULL),
1138 streambuf_(buf, len),
1139 ctr_(ctr),
1140 self_(this) {
1141 rdbuf(&streambuf_);
1142 }
1143
1144 int ctr() const { return ctr_; }
1145 void set_ctr(int ctr) { ctr_ = ctr; }
1146 LogStream* self() const { return self_; }
1147
1148 // Legacy std::streambuf methods.
1149 size_t pcount() const { return streambuf_.pcount(); }
1150 char* pbase() const { return streambuf_.pbase(); }
1151 char* str() const { return pbase(); }
1152
1153 private:
1154 base_logging::LogStreamBuf streambuf_;
1155 int ctr_; // Counter hack (for the LOG_EVERY_X() macro)
1156 LogStream *self_; // Consistency check hack
1157 };
1158
1159public:
1160 // icc 8 requires this typedef to avoid an internal compiler error.
1161 typedef void (LogMessage::*SendMethod)();
1162
1163 LogMessage(const char* file, int line, LogSeverity severity, int ctr,
1164 SendMethod send_method);
1165
1166 // Two special constructors that generate reduced amounts of code at
1167 // LOG call sites for common cases.
1168
1169 // Used for LOG(INFO): Implied are:
1170 // severity = INFO, ctr = 0, send_method = &LogMessage::SendToLog.
1171 //
1172 // Using this constructor instead of the more complex constructor above
1173 // saves 19 bytes per call site.
1174 LogMessage(const char* file, int line);
1175
1176 // Used for LOG(severity) where severity != INFO. Implied
1177 // are: ctr = 0, send_method = &LogMessage::SendToLog
1178 //
1179 // Using this constructor instead of the more complex constructor above
1180 // saves 17 bytes per call site.
1181 LogMessage(const char* file, int line, LogSeverity severity);
1182
1183 // Constructor to log this message to a specified sink (if not NULL).
1184 // Implied are: ctr = 0, send_method = &LogMessage::SendToSinkAndLog if
1185 // also_send_to_log is true, send_method = &LogMessage::SendToSink otherwise.
1186 LogMessage(const char* file, int line, LogSeverity severity, LogSink* sink,
1187 bool also_send_to_log);
1188
1189 // Constructor where we also give a vector<string> pointer
1190 // for storing the messages (if the pointer is not NULL).
1191 // Implied are: ctr = 0, send_method = &LogMessage::SaveOrSendToLog.
1192 LogMessage(const char* file, int line, LogSeverity severity,
1193 std::vector<std::string>* outvec);
1194
1195 // Constructor where we also give a string pointer for storing the
1196 // message (if the pointer is not NULL). Implied are: ctr = 0,
1197 // send_method = &LogMessage::WriteToStringAndLog.
1198 LogMessage(const char* file, int line, LogSeverity severity,
1199 std::string* message);
1200
1201 // A special constructor used for check failures
1202 LogMessage(const char* file, int line, const CheckOpString& result);
1203
1204 ~LogMessage();
1205
1206 // Flush a buffered message to the sink set in the constructor. Always
1207 // called by the destructor, it may also be called from elsewhere if
1208 // needed. Only the first call is actioned; any later ones are ignored.
1209 void Flush();
1210
1211 // An arbitrary limit on the length of a single log message. This
1212 // is so that streaming can be done more efficiently.
1213 static const size_t kMaxLogMessageLen;
1214
1215 // Theses should not be called directly outside of logging.*,
1216 // only passed as SendMethod arguments to other LogMessage methods:
1217 void SendToLog(); // Actually dispatch to the logs
1218 void SendToSyslogAndLog(); // Actually dispatch to syslog and the logs
1219
1220 // Call abort() or similar to perform LOG(FATAL) crash.
1221 static void Fail() __attribute__ ((noreturn));
1222
1223 std::ostream& stream();
1224
1225 int preserved_errno() const;
1226
1227 // Must be called without the log_mutex held. (L < log_mutex)
1228 static int64 num_messages(int severity);
1229
1230 struct LogMessageData;
1231
1232private:
1233 // Fully internal SendMethod cases:
1234 void SendToSinkAndLog(); // Send to sink if provided and dispatch to the logs
1235 void SendToSink(); // Send to sink if provided, do nothing otherwise.
1236
1237 // Write to string if provided and dispatch to the logs.
1238 void WriteToStringAndLog();
1239
1240 void SaveOrSendToLog(); // Save to stringvec if provided, else to logs
1241
1242 void Init(const char* file, int line, LogSeverity severity,
1243 void (LogMessage::*send_method)());
1244
1245 // Used to fill in crash information during LOG(FATAL) failures.
1246 void RecordCrashReason(glog_internal_namespace_::CrashReason* reason);
1247
1248 // Counts of messages sent at each priority:
1249 static int64 num_messages_[NUM_SEVERITIES]; // under log_mutex
1250
1251 // We keep the data in a separate struct so that each instance of
1252 // LogMessage uses less stack space.
1253 LogMessageData* allocated_;
1254 LogMessageData* data_;
1255
1256 friend class LogDestination;
1257
1258 LogMessage(const LogMessage&);
1259 void operator=(const LogMessage&);
1260};
1261
1262// This class happens to be thread-hostile because all instances share
1263// a single data buffer, but since it can only be created just before
1264// the process dies, we don't worry so much.
1265class GOOGLE_GLOG_DLL_DECL LogMessageFatal : public LogMessage {
1266 public:
1267 LogMessageFatal(const char* file, int line);
1268 LogMessageFatal(const char* file, int line, const CheckOpString& result);
1269 ~LogMessageFatal() __attribute__ ((noreturn));
1270};
1271
1272// A non-macro interface to the log facility; (useful
1273// when the logging level is not a compile-time constant).
1274inline void LogAtLevel(int const severity, std::string const &msg) {
1275 LogMessage(__FILE__, __LINE__, severity).stream() << msg;
1276}
1277
1278// A macro alternative of LogAtLevel. New code may want to use this
1279// version since there are two advantages: 1. this version outputs the
1280// file name and the line number where this macro is put like other
1281// LOG macros, 2. this macro can be used as C++ stream.
1282#define LOG_AT_LEVEL(severity) google::LogMessage(__FILE__, __LINE__, severity).stream()
1283
1284// A small helper for CHECK_NOTNULL().
1285template <typename T>
1286T* CheckNotNull(const char *file, int line, const char *names, T* t) {
1287 if (t == NULL) {
1288 LogMessageFatal(file, line, new std::string(names));
1289 }
1290 return t;
1291}
1292
1293// Allow folks to put a counter in the LOG_EVERY_X()'ed messages. This
1294// only works if ostream is a LogStream. If the ostream is not a
1295// LogStream you'll get an assert saying as much at runtime.
1296GOOGLE_GLOG_DLL_DECL std::ostream& operator<<(std::ostream &os,
1297 const PRIVATE_Counter&);
1298
1299
1300// Derived class for PLOG*() above.
1301class GOOGLE_GLOG_DLL_DECL ErrnoLogMessage : public LogMessage {
1302 public:
1303
1304 ErrnoLogMessage(const char* file, int line, LogSeverity severity, int ctr,
1305 void (LogMessage::*send_method)());
1306
1307 // Postpends ": strerror(errno) [errno]".
1308 ~ErrnoLogMessage();
1309
1310 private:
1311 ErrnoLogMessage(const ErrnoLogMessage&);
1312 void operator=(const ErrnoLogMessage&);
1313};
1314
1315
1316// This class is used to explicitly ignore values in the conditional
1317// logging macros. This avoids compiler warnings like "value computed
1318// is not used" and "statement has no effect".
1319
1320class GOOGLE_GLOG_DLL_DECL LogMessageVoidify {
1321 public:
1322 LogMessageVoidify() { }
1323 // This has to be an operator with a precedence lower than << but
1324 // higher than ?:
1325 void operator&(std::ostream&) { }
1326};
1327
1328
1329// Flushes all log files that contains messages that are at least of
1330// the specified severity level. Thread-safe.
1331GOOGLE_GLOG_DLL_DECL void FlushLogFiles(LogSeverity min_severity);
1332
1333// Flushes all log files that contains messages that are at least of
1334// the specified severity level. Thread-hostile because it ignores
1335// locking -- used for catastrophic failures.
1336GOOGLE_GLOG_DLL_DECL void FlushLogFilesUnsafe(LogSeverity min_severity);
1337
1338//
1339// Set the destination to which a particular severity level of log
1340// messages is sent. If base_filename is "", it means "don't log this
1341// severity". Thread-safe.
1342//
1343GOOGLE_GLOG_DLL_DECL void SetLogDestination(LogSeverity severity,
1344 const char* base_filename);
1345
1346//
1347// Set the basename of the symlink to the latest log file at a given
1348// severity. If symlink_basename is empty, do not make a symlink. If
1349// you don't call this function, the symlink basename is the
1350// invocation name of the program. Thread-safe.
1351//
1352GOOGLE_GLOG_DLL_DECL void SetLogSymlink(LogSeverity severity,
1353 const char* symlink_basename);
1354
1355//
1356// Used to send logs to some other kind of destination
1357// Users should subclass LogSink and override send to do whatever they want.
1358// Implementations must be thread-safe because a shared instance will
1359// be called from whichever thread ran the LOG(XXX) line.
1360class GOOGLE_GLOG_DLL_DECL LogSink {
1361 public:
1362 virtual ~LogSink();
1363
1364 // Sink's logging logic (message_len is such as to exclude '\n' at the end).
1365 // This method can't use LOG() or CHECK() as logging system mutex(s) are held
1366 // during this call.
1367 virtual void send(LogSeverity severity, const char* full_filename,
1368 const char* base_filename, int line,
1369 const struct ::tm* tm_time,
1370 const char* message, size_t message_len) = 0;
1371
1372 // Redefine this to implement waiting for
1373 // the sink's logging logic to complete.
1374 // It will be called after each send() returns,
1375 // but before that LogMessage exits or crashes.
1376 // By default this function does nothing.
1377 // Using this function one can implement complex logic for send()
1378 // that itself involves logging; and do all this w/o causing deadlocks and
1379 // inconsistent rearrangement of log messages.
1380 // E.g. if a LogSink has thread-specific actions, the send() method
1381 // can simply add the message to a queue and wake up another thread that
1382 // handles real logging while itself making some LOG() calls;
1383 // WaitTillSent() can be implemented to wait for that logic to complete.
1384 // See our unittest for an example.
1385 virtual void WaitTillSent();
1386
1387 // Returns the normal text output of the log message.
1388 // Can be useful to implement send().
1389 static std::string ToString(LogSeverity severity, const char* file, int line,
1390 const struct ::tm* tm_time,
1391 const char* message, size_t message_len);
1392};
1393
1394// Add or remove a LogSink as a consumer of logging data. Thread-safe.
1395GOOGLE_GLOG_DLL_DECL void AddLogSink(LogSink *destination);
1396GOOGLE_GLOG_DLL_DECL void RemoveLogSink(LogSink *destination);
1397
1398//
1399// Specify an "extension" added to the filename specified via
1400// SetLogDestination. This applies to all severity levels. It's
1401// often used to append the port we're listening on to the logfile
1402// name. Thread-safe.
1403//
1404GOOGLE_GLOG_DLL_DECL void SetLogFilenameExtension(
1405 const char* filename_extension);
1406
1407//
1408// Make it so that all log messages of at least a particular severity
1409// are logged to stderr (in addition to logging to the usual log
1410// file(s)). Thread-safe.
1411//
1412GOOGLE_GLOG_DLL_DECL void SetStderrLogging(LogSeverity min_severity);
1413
1414//
1415// Make it so that all log messages go only to stderr. Thread-safe.
1416//
1417GOOGLE_GLOG_DLL_DECL void LogToStderr();
1418
1419//
1420// Make it so that all log messages of at least a particular severity are
1421// logged via email to a list of addresses (in addition to logging to the
1422// usual log file(s)). The list of addresses is just a string containing
1423// the email addresses to send to (separated by spaces, say). Thread-safe.
1424//
1425GOOGLE_GLOG_DLL_DECL void SetEmailLogging(LogSeverity min_severity,
1426 const char* addresses);
1427
1428// A simple function that sends email. dest is a commma-separated
1429// list of addressess. Thread-safe.
1430GOOGLE_GLOG_DLL_DECL bool SendEmail(const char *dest,
1431 const char *subject, const char *body);
1432
1433GOOGLE_GLOG_DLL_DECL const std::vector<std::string>& GetLoggingDirectories();
1434
1435// For tests only: Clear the internal [cached] list of logging directories to
1436// force a refresh the next time GetLoggingDirectories is called.
1437// Thread-hostile.
1438void TestOnly_ClearLoggingDirectoriesList();
1439
1440// Returns a set of existing temporary directories, which will be a
1441// subset of the directories returned by GetLogginDirectories().
1442// Thread-safe.
1443GOOGLE_GLOG_DLL_DECL void GetExistingTempDirectories(
1444 std::vector<std::string>* list);
1445
1446// Print any fatal message again -- useful to call from signal handler
1447// so that the last thing in the output is the fatal message.
1448// Thread-hostile, but a race is unlikely.
1449GOOGLE_GLOG_DLL_DECL void ReprintFatalMessage();
1450
1451// Truncate a log file that may be the append-only output of multiple
1452// processes and hence can't simply be renamed/reopened (typically a
1453// stdout/stderr). If the file "path" is > "limit" bytes, copy the
1454// last "keep" bytes to offset 0 and truncate the rest. Since we could
1455// be racing with other writers, this approach has the potential to
1456// lose very small amounts of data. For security, only follow symlinks
1457// if the path is /proc/self/fd/*
1458GOOGLE_GLOG_DLL_DECL void TruncateLogFile(const char *path,
1459 int64 limit, int64 keep);
1460
1461// Truncate stdout and stderr if they are over the value specified by
1462// --max_log_size; keep the final 1MB. This function has the same
1463// race condition as TruncateLogFile.
1464GOOGLE_GLOG_DLL_DECL void TruncateStdoutStderr();
1465
1466// Return the string representation of the provided LogSeverity level.
1467// Thread-safe.
1468GOOGLE_GLOG_DLL_DECL const char* GetLogSeverityName(LogSeverity severity);
1469
1470// ---------------------------------------------------------------------
1471// Implementation details that are not useful to most clients
1472// ---------------------------------------------------------------------
1473
1474// A Logger is the interface used by logging modules to emit entries
1475// to a log. A typical implementation will dump formatted data to a
1476// sequence of files. We also provide interfaces that will forward
1477// the data to another thread so that the invoker never blocks.
1478// Implementations should be thread-safe since the logging system
1479// will write to them from multiple threads.
1480
1481namespace base {
1482
1483class GOOGLE_GLOG_DLL_DECL Logger {
1484 public:
1485 virtual ~Logger();
1486
1487 // Writes "message[0,message_len-1]" corresponding to an event that
1488 // occurred at "timestamp". If "force_flush" is true, the log file
1489 // is flushed immediately.
1490 //
1491 // The input message has already been formatted as deemed
1492 // appropriate by the higher level logging facility. For example,
1493 // textual log messages already contain timestamps, and the
1494 // file:linenumber header.
1495 virtual void Write(bool force_flush,
1496 time_t timestamp,
1497 const char* message,
1498 int message_len) = 0;
1499
1500 // Flush any buffered messages
1501 virtual void Flush() = 0;
1502
1503 // Get the current LOG file size.
1504 // The returned value is approximate since some
1505 // logged data may not have been flushed to disk yet.
1506 virtual uint32 LogSize() = 0;
1507};
1508
1509// Get the logger for the specified severity level. The logger
1510// remains the property of the logging module and should not be
1511// deleted by the caller. Thread-safe.
1512extern GOOGLE_GLOG_DLL_DECL Logger* GetLogger(LogSeverity level);
1513
1514// Set the logger for the specified severity level. The logger
1515// becomes the property of the logging module and should not
1516// be deleted by the caller. Thread-safe.
1517extern GOOGLE_GLOG_DLL_DECL void SetLogger(LogSeverity level, Logger* logger);
1518
1519}
1520
1521// glibc has traditionally implemented two incompatible versions of
1522// strerror_r(). There is a poorly defined convention for picking the
1523// version that we want, but it is not clear whether it even works with
1524// all versions of glibc.
1525// So, instead, we provide this wrapper that automatically detects the
1526// version that is in use, and then implements POSIX semantics.
1527// N.B. In addition to what POSIX says, we also guarantee that "buf" will
1528// be set to an empty string, if this function failed. This means, in most
1529// cases, you do not need to check the error code and you can directly
1530// use the value of "buf". It will never have an undefined value.
1531// DEPRECATED: Use StrError(int) instead.
1532GOOGLE_GLOG_DLL_DECL int posix_strerror_r(int err, char *buf, size_t len);
1533
1534// A thread-safe replacement for strerror(). Returns a string describing the
1535// given POSIX error code.
1536GOOGLE_GLOG_DLL_DECL std::string StrError(int err);
1537
1538// A class for which we define operator<<, which does nothing.
1539class GOOGLE_GLOG_DLL_DECL NullStream : public LogMessage::LogStream {
1540 public:
1541 // Initialize the LogStream so the messages can be written somewhere
1542 // (they'll never be actually displayed). This will be needed if a
1543 // NullStream& is implicitly converted to LogStream&, in which case
1544 // the overloaded NullStream::operator<< will not be invoked.
1545 NullStream() : LogMessage::LogStream(message_buffer_, 1, 0) { }
1546 NullStream(const char* /*file*/, int /*line*/,
1547 const CheckOpString& /*result*/) :
1548 LogMessage::LogStream(message_buffer_, 1, 0) { }
1549 NullStream &stream() { return *this; }
1550 private:
1551 // A very short buffer for messages (which we discard anyway). This
1552 // will be needed if NullStream& converted to LogStream& (e.g. as a
1553 // result of a conditional expression).
1554 char message_buffer_[2];
1555};
1556
1557// Do nothing. This operator is inline, allowing the message to be
1558// compiled away. The message will not be compiled away if we do
1559// something like (flag ? LOG(INFO) : LOG(ERROR)) << message; when
1560// SKIP_LOG=WARNING. In those cases, NullStream will be implicitly
1561// converted to LogStream and the message will be computed and then
1562// quietly discarded.
1563template<class T>
1564inline NullStream& operator<<(NullStream &str, const T &) { return str; }
1565
1566// Similar to NullStream, but aborts the program (without stack
1567// trace), like LogMessageFatal.
1568class GOOGLE_GLOG_DLL_DECL NullStreamFatal : public NullStream {
1569 public:
1570 NullStreamFatal() { }
1571 NullStreamFatal(const char* file, int line, const CheckOpString& result) :
1572 NullStream(file, line, result) { }
1573 __attribute__ ((noreturn)) ~NullStreamFatal() { _exit(1); }
1574};
1575
1576// Install a signal handler that will dump signal information and a stack
1577// trace when the program crashes on certain signals. We'll install the
1578// signal handler for the following signals.
1579//
1580// SIGSEGV, SIGILL, SIGFPE, SIGABRT, SIGBUS, and SIGTERM.
1581//
1582// By default, the signal handler will write the failure dump to the
1583// standard error. You can customize the destination by installing your
1584// own writer function by InstallFailureWriter() below.
1585//
1586// Note on threading:
1587//
1588// The function should be called before threads are created, if you want
1589// to use the failure signal handler for all threads. The stack trace
1590// will be shown only for the thread that receives the signal. In other
1591// words, stack traces of other threads won't be shown.
1592GOOGLE_GLOG_DLL_DECL void InstallFailureSignalHandler();
1593
1594// Installs a function that is used for writing the failure dump. "data"
1595// is the pointer to the beginning of a message to be written, and "size"
1596// is the size of the message. You should not expect the data is
1597// terminated with '\0'.
1598GOOGLE_GLOG_DLL_DECL void InstallFailureWriter(
1599 void (*writer)(const char* data, int size));
1600
1601}
1602
1603#endif // _LOGGING_H_
1604