logging.h revision 0529e5d033099cbfc42635f6f6183833b09dff6e
1// Copyright (c) 2012 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5#ifndef BASE_LOGGING_H_ 6#define BASE_LOGGING_H_ 7 8#include <cassert> 9#include <string> 10#include <cstring> 11#include <sstream> 12 13#include "base/base_export.h" 14#include "base/basictypes.h" 15#include "base/debug/debugger.h" 16#include "build/build_config.h" 17 18// 19// Optional message capabilities 20// ----------------------------- 21// Assertion failed messages and fatal errors are displayed in a dialog box 22// before the application exits. However, running this UI creates a message 23// loop, which causes application messages to be processed and potentially 24// dispatched to existing application windows. Since the application is in a 25// bad state when this assertion dialog is displayed, these messages may not 26// get processed and hang the dialog, or the application might go crazy. 27// 28// Therefore, it can be beneficial to display the error dialog in a separate 29// process from the main application. When the logging system needs to display 30// a fatal error dialog box, it will look for a program called 31// "DebugMessage.exe" in the same directory as the application executable. It 32// will run this application with the message as the command line, and will 33// not include the name of the application as is traditional for easier 34// parsing. 35// 36// The code for DebugMessage.exe is only one line. In WinMain, do: 37// MessageBox(NULL, GetCommandLineW(), L"Fatal Error", 0); 38// 39// If DebugMessage.exe is not found, the logging code will use a normal 40// MessageBox, potentially causing the problems discussed above. 41 42 43// Instructions 44// ------------ 45// 46// Make a bunch of macros for logging. The way to log things is to stream 47// things to LOG(<a particular severity level>). E.g., 48// 49// LOG(INFO) << "Found " << num_cookies << " cookies"; 50// 51// You can also do conditional logging: 52// 53// LOG_IF(INFO, num_cookies > 10) << "Got lots of cookies"; 54// 55// The CHECK(condition) macro is active in both debug and release builds and 56// effectively performs a LOG(FATAL) which terminates the process and 57// generates a crashdump unless a debugger is attached. 58// 59// There are also "debug mode" logging macros like the ones above: 60// 61// DLOG(INFO) << "Found cookies"; 62// 63// DLOG_IF(INFO, num_cookies > 10) << "Got lots of cookies"; 64// 65// All "debug mode" logging is compiled away to nothing for non-debug mode 66// compiles. LOG_IF and development flags also work well together 67// because the code can be compiled away sometimes. 68// 69// We also have 70// 71// LOG_ASSERT(assertion); 72// DLOG_ASSERT(assertion); 73// 74// which is syntactic sugar for {,D}LOG_IF(FATAL, assert fails) << assertion; 75// 76// There are "verbose level" logging macros. They look like 77// 78// VLOG(1) << "I'm printed when you run the program with --v=1 or more"; 79// VLOG(2) << "I'm printed when you run the program with --v=2 or more"; 80// 81// These always log at the INFO log level (when they log at all). 82// The verbose logging can also be turned on module-by-module. For instance, 83// --vmodule=profile=2,icon_loader=1,browser_*=3,*/chromeos/*=4 --v=0 84// will cause: 85// a. VLOG(2) and lower messages to be printed from profile.{h,cc} 86// b. VLOG(1) and lower messages to be printed from icon_loader.{h,cc} 87// c. VLOG(3) and lower messages to be printed from files prefixed with 88// "browser" 89// d. VLOG(4) and lower messages to be printed from files under a 90// "chromeos" directory. 91// e. VLOG(0) and lower messages to be printed from elsewhere 92// 93// The wildcarding functionality shown by (c) supports both '*' (match 94// 0 or more characters) and '?' (match any single character) 95// wildcards. Any pattern containing a forward or backward slash will 96// be tested against the whole pathname and not just the module. 97// E.g., "*/foo/bar/*=2" would change the logging level for all code 98// in source files under a "foo/bar" directory. 99// 100// There's also VLOG_IS_ON(n) "verbose level" condition macro. To be used as 101// 102// if (VLOG_IS_ON(2)) { 103// // do some logging preparation and logging 104// // that can't be accomplished with just VLOG(2) << ...; 105// } 106// 107// There is also a VLOG_IF "verbose level" condition macro for sample 108// cases, when some extra computation and preparation for logs is not 109// needed. 110// 111// VLOG_IF(1, (size > 1024)) 112// << "I'm printed when size is more than 1024 and when you run the " 113// "program with --v=1 or more"; 114// 115// We also override the standard 'assert' to use 'DLOG_ASSERT'. 116// 117// Lastly, there is: 118// 119// PLOG(ERROR) << "Couldn't do foo"; 120// DPLOG(ERROR) << "Couldn't do foo"; 121// PLOG_IF(ERROR, cond) << "Couldn't do foo"; 122// DPLOG_IF(ERROR, cond) << "Couldn't do foo"; 123// PCHECK(condition) << "Couldn't do foo"; 124// DPCHECK(condition) << "Couldn't do foo"; 125// 126// which append the last system error to the message in string form (taken from 127// GetLastError() on Windows and errno on POSIX). 128// 129// The supported severity levels for macros that allow you to specify one 130// are (in increasing order of severity) INFO, WARNING, ERROR, ERROR_REPORT, 131// and FATAL. 132// 133// Very important: logging a message at the FATAL severity level causes 134// the program to terminate (after the message is logged). 135// 136// Note the special severity of ERROR_REPORT only available/relevant in normal 137// mode, which displays error dialog without terminating the program. There is 138// no error dialog for severity ERROR or below in normal mode. 139// 140// There is also the special severity of DFATAL, which logs FATAL in 141// debug mode, ERROR in normal mode. 142 143namespace logging { 144 145// TODO(avi): do we want to do a unification of character types here? 146#if defined(OS_WIN) 147typedef wchar_t PathChar; 148#else 149typedef char PathChar; 150#endif 151 152// Where to record logging output? A flat file and/or system debug log 153// via OutputDebugString. 154enum LoggingDestination { 155 LOG_NONE = 0, 156 LOG_TO_FILE = 1 << 0, 157 LOG_TO_SYSTEM_DEBUG_LOG = 1 << 1, 158 159 LOG_TO_ALL = LOG_TO_FILE | LOG_TO_SYSTEM_DEBUG_LOG, 160 161 // On Windows, use a file next to the exe; on POSIX platforms, where 162 // it may not even be possible to locate the executable on disk, use 163 // stderr. 164#if defined(OS_WIN) 165 LOG_DEFAULT = LOG_TO_FILE, 166#elif defined(OS_POSIX) 167 LOG_DEFAULT = LOG_TO_SYSTEM_DEBUG_LOG, 168#endif 169}; 170 171// Indicates that the log file should be locked when being written to. 172// Unless there is only one single-threaded process that is logging to 173// the log file, the file should be locked during writes to make each 174// log output atomic. Other writers will block. 175// 176// All processes writing to the log file must have their locking set for it to 177// work properly. Defaults to LOCK_LOG_FILE. 178enum LogLockingState { LOCK_LOG_FILE, DONT_LOCK_LOG_FILE }; 179 180// On startup, should we delete or append to an existing log file (if any)? 181// Defaults to APPEND_TO_OLD_LOG_FILE. 182enum OldFileDeletionState { DELETE_OLD_LOG_FILE, APPEND_TO_OLD_LOG_FILE }; 183 184struct BASE_EXPORT LoggingSettings { 185 // The defaults values are: 186 // 187 // logging_dest: LOG_DEFAULT 188 // log_file: NULL 189 // lock_log: LOCK_LOG_FILE 190 // delete_old: APPEND_TO_OLD_LOG_FILE 191 LoggingSettings(); 192 193 LoggingDestination logging_dest; 194 195 // The three settings below have an effect only when LOG_TO_FILE is 196 // set in |logging_dest|. 197 const PathChar* log_file; 198 LogLockingState lock_log; 199 OldFileDeletionState delete_old; 200}; 201 202// Define different names for the BaseInitLoggingImpl() function depending on 203// whether NDEBUG is defined or not so that we'll fail to link if someone tries 204// to compile logging.cc with NDEBUG but includes logging.h without defining it, 205// or vice versa. 206#if NDEBUG 207#define BaseInitLoggingImpl BaseInitLoggingImpl_built_with_NDEBUG 208#else 209#define BaseInitLoggingImpl BaseInitLoggingImpl_built_without_NDEBUG 210#endif 211 212// Implementation of the InitLogging() method declared below. We use a 213// more-specific name so we can #define it above without affecting other code 214// that has named stuff "InitLogging". 215BASE_EXPORT bool BaseInitLoggingImpl(const LoggingSettings& settings); 216 217// Sets the log file name and other global logging state. Calling this function 218// is recommended, and is normally done at the beginning of application init. 219// If you don't call it, all the flags will be initialized to their default 220// values, and there is a race condition that may leak a critical section 221// object if two threads try to do the first log at the same time. 222// See the definition of the enums above for descriptions and default values. 223// 224// The default log file is initialized to "debug.log" in the application 225// directory. You probably don't want this, especially since the program 226// directory may not be writable on an enduser's system. 227// 228// This function may be called a second time to re-direct logging (e.g after 229// loging in to a user partition), however it should never be called more than 230// twice. 231inline bool InitLogging(const LoggingSettings& settings) { 232 return BaseInitLoggingImpl(settings); 233} 234 235// Sets the log level. Anything at or above this level will be written to the 236// log file/displayed to the user (if applicable). Anything below this level 237// will be silently ignored. The log level defaults to 0 (everything is logged 238// up to level INFO) if this function is not called. 239// Note that log messages for VLOG(x) are logged at level -x, so setting 240// the min log level to negative values enables verbose logging. 241BASE_EXPORT void SetMinLogLevel(int level); 242 243// Gets the current log level. 244BASE_EXPORT int GetMinLogLevel(); 245 246// Gets the VLOG default verbosity level. 247BASE_EXPORT int GetVlogVerbosity(); 248 249// Gets the current vlog level for the given file (usually taken from 250// __FILE__). 251 252// Note that |N| is the size *with* the null terminator. 253BASE_EXPORT int GetVlogLevelHelper(const char* file_start, size_t N); 254 255template <size_t N> 256int GetVlogLevel(const char (&file)[N]) { 257 return GetVlogLevelHelper(file, N); 258} 259 260// Sets the common items you want to be prepended to each log message. 261// process and thread IDs default to off, the timestamp defaults to on. 262// If this function is not called, logging defaults to writing the timestamp 263// only. 264BASE_EXPORT void SetLogItems(bool enable_process_id, bool enable_thread_id, 265 bool enable_timestamp, bool enable_tickcount); 266 267// Sets whether or not you'd like to see fatal debug messages popped up in 268// a dialog box or not. 269// Dialogs are not shown by default. 270BASE_EXPORT void SetShowErrorDialogs(bool enable_dialogs); 271 272// Sets the Log Assert Handler that will be used to notify of check failures. 273// The default handler shows a dialog box and then terminate the process, 274// however clients can use this function to override with their own handling 275// (e.g. a silent one for Unit Tests) 276typedef void (*LogAssertHandlerFunction)(const std::string& str); 277BASE_EXPORT void SetLogAssertHandler(LogAssertHandlerFunction handler); 278 279// Sets the Log Report Handler that will be used to notify of check failures 280// in non-debug mode. The default handler shows a dialog box and continues 281// the execution, however clients can use this function to override with their 282// own handling. 283typedef void (*LogReportHandlerFunction)(const std::string& str); 284BASE_EXPORT void SetLogReportHandler(LogReportHandlerFunction handler); 285 286// Sets the Log Message Handler that gets passed every log message before 287// it's sent to other log destinations (if any). 288// Returns true to signal that it handled the message and the message 289// should not be sent to other log destinations. 290typedef bool (*LogMessageHandlerFunction)(int severity, 291 const char* file, int line, size_t message_start, const std::string& str); 292BASE_EXPORT void SetLogMessageHandler(LogMessageHandlerFunction handler); 293BASE_EXPORT LogMessageHandlerFunction GetLogMessageHandler(); 294 295typedef int LogSeverity; 296const LogSeverity LOG_VERBOSE = -1; // This is level 1 verbosity 297// Note: the log severities are used to index into the array of names, 298// see log_severity_names. 299const LogSeverity LOG_INFO = 0; 300const LogSeverity LOG_WARNING = 1; 301const LogSeverity LOG_ERROR = 2; 302const LogSeverity LOG_ERROR_REPORT = 3; 303const LogSeverity LOG_FATAL = 4; 304const LogSeverity LOG_NUM_SEVERITIES = 5; 305 306// LOG_DFATAL is LOG_FATAL in debug mode, ERROR in normal mode 307#ifdef NDEBUG 308const LogSeverity LOG_DFATAL = LOG_ERROR; 309#else 310const LogSeverity LOG_DFATAL = LOG_FATAL; 311#endif 312 313// A few definitions of macros that don't generate much code. These are used 314// by LOG() and LOG_IF, etc. Since these are used all over our code, it's 315// better to have compact code for these operations. 316#define COMPACT_GOOGLE_LOG_EX_INFO(ClassName, ...) \ 317 logging::ClassName(__FILE__, __LINE__, logging::LOG_INFO , ##__VA_ARGS__) 318#define COMPACT_GOOGLE_LOG_EX_WARNING(ClassName, ...) \ 319 logging::ClassName(__FILE__, __LINE__, logging::LOG_WARNING , ##__VA_ARGS__) 320#define COMPACT_GOOGLE_LOG_EX_ERROR(ClassName, ...) \ 321 logging::ClassName(__FILE__, __LINE__, logging::LOG_ERROR , ##__VA_ARGS__) 322#define COMPACT_GOOGLE_LOG_EX_ERROR_REPORT(ClassName, ...) \ 323 logging::ClassName(__FILE__, __LINE__, \ 324 logging::LOG_ERROR_REPORT , ##__VA_ARGS__) 325#define COMPACT_GOOGLE_LOG_EX_FATAL(ClassName, ...) \ 326 logging::ClassName(__FILE__, __LINE__, logging::LOG_FATAL , ##__VA_ARGS__) 327#define COMPACT_GOOGLE_LOG_EX_DFATAL(ClassName, ...) \ 328 logging::ClassName(__FILE__, __LINE__, logging::LOG_DFATAL , ##__VA_ARGS__) 329 330#define COMPACT_GOOGLE_LOG_INFO \ 331 COMPACT_GOOGLE_LOG_EX_INFO(LogMessage) 332#define COMPACT_GOOGLE_LOG_WARNING \ 333 COMPACT_GOOGLE_LOG_EX_WARNING(LogMessage) 334#define COMPACT_GOOGLE_LOG_ERROR \ 335 COMPACT_GOOGLE_LOG_EX_ERROR(LogMessage) 336#define COMPACT_GOOGLE_LOG_ERROR_REPORT \ 337 COMPACT_GOOGLE_LOG_EX_ERROR_REPORT(LogMessage) 338#define COMPACT_GOOGLE_LOG_FATAL \ 339 COMPACT_GOOGLE_LOG_EX_FATAL(LogMessage) 340#define COMPACT_GOOGLE_LOG_DFATAL \ 341 COMPACT_GOOGLE_LOG_EX_DFATAL(LogMessage) 342 343#if defined(OS_WIN) 344// wingdi.h defines ERROR to be 0. When we call LOG(ERROR), it gets 345// substituted with 0, and it expands to COMPACT_GOOGLE_LOG_0. To allow us 346// to keep using this syntax, we define this macro to do the same thing 347// as COMPACT_GOOGLE_LOG_ERROR, and also define ERROR the same way that 348// the Windows SDK does for consistency. 349#define ERROR 0 350#define COMPACT_GOOGLE_LOG_EX_0(ClassName, ...) \ 351 COMPACT_GOOGLE_LOG_EX_ERROR(ClassName , ##__VA_ARGS__) 352#define COMPACT_GOOGLE_LOG_0 COMPACT_GOOGLE_LOG_ERROR 353// Needed for LOG_IS_ON(ERROR). 354const LogSeverity LOG_0 = LOG_ERROR; 355#endif 356 357// As special cases, we can assume that LOG_IS_ON(ERROR_REPORT) and 358// LOG_IS_ON(FATAL) always hold. Also, LOG_IS_ON(DFATAL) always holds 359// in debug mode. In particular, CHECK()s will always fire if they 360// fail. 361#define LOG_IS_ON(severity) \ 362 ((::logging::LOG_ ## severity) >= ::logging::GetMinLogLevel()) 363 364// We can't do any caching tricks with VLOG_IS_ON() like the 365// google-glog version since it requires GCC extensions. This means 366// that using the v-logging functions in conjunction with --vmodule 367// may be slow. 368#define VLOG_IS_ON(verboselevel) \ 369 ((verboselevel) <= ::logging::GetVlogLevel(__FILE__)) 370 371// Helper macro which avoids evaluating the arguments to a stream if 372// the condition doesn't hold. 373#define LAZY_STREAM(stream, condition) \ 374 !(condition) ? (void) 0 : ::logging::LogMessageVoidify() & (stream) 375 376// We use the preprocessor's merging operator, "##", so that, e.g., 377// LOG(INFO) becomes the token COMPACT_GOOGLE_LOG_INFO. There's some funny 378// subtle difference between ostream member streaming functions (e.g., 379// ostream::operator<<(int) and ostream non-member streaming functions 380// (e.g., ::operator<<(ostream&, string&): it turns out that it's 381// impossible to stream something like a string directly to an unnamed 382// ostream. We employ a neat hack by calling the stream() member 383// function of LogMessage which seems to avoid the problem. 384#define LOG_STREAM(severity) COMPACT_GOOGLE_LOG_ ## severity.stream() 385 386#define LOG(severity) LAZY_STREAM(LOG_STREAM(severity), LOG_IS_ON(severity)) 387#define LOG_IF(severity, condition) \ 388 LAZY_STREAM(LOG_STREAM(severity), LOG_IS_ON(severity) && (condition)) 389 390#define SYSLOG(severity) LOG(severity) 391#define SYSLOG_IF(severity, condition) LOG_IF(severity, condition) 392 393// The VLOG macros log with negative verbosities. 394#define VLOG_STREAM(verbose_level) \ 395 logging::LogMessage(__FILE__, __LINE__, -verbose_level).stream() 396 397#define VLOG(verbose_level) \ 398 LAZY_STREAM(VLOG_STREAM(verbose_level), VLOG_IS_ON(verbose_level)) 399 400#define VLOG_IF(verbose_level, condition) \ 401 LAZY_STREAM(VLOG_STREAM(verbose_level), \ 402 VLOG_IS_ON(verbose_level) && (condition)) 403 404#if defined (OS_WIN) 405#define VPLOG_STREAM(verbose_level) \ 406 logging::Win32ErrorLogMessage(__FILE__, __LINE__, -verbose_level, \ 407 ::logging::GetLastSystemErrorCode()).stream() 408#elif defined(OS_POSIX) 409#define VPLOG_STREAM(verbose_level) \ 410 logging::ErrnoLogMessage(__FILE__, __LINE__, -verbose_level, \ 411 ::logging::GetLastSystemErrorCode()).stream() 412#endif 413 414#define VPLOG(verbose_level) \ 415 LAZY_STREAM(VPLOG_STREAM(verbose_level), VLOG_IS_ON(verbose_level)) 416 417#define VPLOG_IF(verbose_level, condition) \ 418 LAZY_STREAM(VPLOG_STREAM(verbose_level), \ 419 VLOG_IS_ON(verbose_level) && (condition)) 420 421// TODO(akalin): Add more VLOG variants, e.g. VPLOG. 422 423#define LOG_ASSERT(condition) \ 424 LOG_IF(FATAL, !(condition)) << "Assert failed: " #condition ". " 425#define SYSLOG_ASSERT(condition) \ 426 SYSLOG_IF(FATAL, !(condition)) << "Assert failed: " #condition ". " 427 428#if defined(OS_WIN) 429#define PLOG_STREAM(severity) \ 430 COMPACT_GOOGLE_LOG_EX_ ## severity(Win32ErrorLogMessage, \ 431 ::logging::GetLastSystemErrorCode()).stream() 432#elif defined(OS_POSIX) 433#define PLOG_STREAM(severity) \ 434 COMPACT_GOOGLE_LOG_EX_ ## severity(ErrnoLogMessage, \ 435 ::logging::GetLastSystemErrorCode()).stream() 436#endif 437 438#define PLOG(severity) \ 439 LAZY_STREAM(PLOG_STREAM(severity), LOG_IS_ON(severity)) 440 441#define PLOG_IF(severity, condition) \ 442 LAZY_STREAM(PLOG_STREAM(severity), LOG_IS_ON(severity) && (condition)) 443 444// The actual stream used isn't important. 445#define EAT_STREAM_PARAMETERS \ 446 true ? (void) 0 : ::logging::LogMessageVoidify() & LOG_STREAM(FATAL) 447 448// CHECK dies with a fatal error if condition is not true. It is *not* 449// controlled by NDEBUG, so the check will be executed regardless of 450// compilation mode. 451// 452// We make sure CHECK et al. always evaluates their arguments, as 453// doing CHECK(FunctionWithSideEffect()) is a common idiom. 454 455#if defined(OFFICIAL_BUILD) && defined(NDEBUG) 456 457// Make all CHECK functions discard their log strings to reduce code 458// bloat for official release builds. 459 460// TODO(akalin): This would be more valuable if there were some way to 461// remove BreakDebugger() from the backtrace, perhaps by turning it 462// into a macro (like __debugbreak() on Windows). 463#define CHECK(condition) \ 464 !(condition) ? ::base::debug::BreakDebugger() : EAT_STREAM_PARAMETERS 465 466#define PCHECK(condition) CHECK(condition) 467 468#define CHECK_OP(name, op, val1, val2) CHECK((val1) op (val2)) 469 470#else 471 472#define CHECK(condition) \ 473 LAZY_STREAM(LOG_STREAM(FATAL), !(condition)) \ 474 << "Check failed: " #condition ". " 475 476#define PCHECK(condition) \ 477 LAZY_STREAM(PLOG_STREAM(FATAL), !(condition)) \ 478 << "Check failed: " #condition ". " 479 480// Helper macro for binary operators. 481// Don't use this macro directly in your code, use CHECK_EQ et al below. 482// 483// TODO(akalin): Rewrite this so that constructs like if (...) 484// CHECK_EQ(...) else { ... } work properly. 485#define CHECK_OP(name, op, val1, val2) \ 486 if (std::string* _result = \ 487 logging::Check##name##Impl((val1), (val2), \ 488 #val1 " " #op " " #val2)) \ 489 logging::LogMessage(__FILE__, __LINE__, _result).stream() 490 491#endif 492 493// Build the error message string. This is separate from the "Impl" 494// function template because it is not performance critical and so can 495// be out of line, while the "Impl" code should be inline. Caller 496// takes ownership of the returned string. 497template<class t1, class t2> 498std::string* MakeCheckOpString(const t1& v1, const t2& v2, const char* names) { 499 std::ostringstream ss; 500 ss << names << " (" << v1 << " vs. " << v2 << ")"; 501 std::string* msg = new std::string(ss.str()); 502 return msg; 503} 504 505// MSVC doesn't like complex extern templates and DLLs. 506#if !defined(COMPILER_MSVC) 507// Commonly used instantiations of MakeCheckOpString<>. Explicitly instantiated 508// in logging.cc. 509extern template BASE_EXPORT std::string* MakeCheckOpString<int, int>( 510 const int&, const int&, const char* names); 511extern template BASE_EXPORT 512std::string* MakeCheckOpString<unsigned long, unsigned long>( 513 const unsigned long&, const unsigned long&, const char* names); 514extern template BASE_EXPORT 515std::string* MakeCheckOpString<unsigned long, unsigned int>( 516 const unsigned long&, const unsigned int&, const char* names); 517extern template BASE_EXPORT 518std::string* MakeCheckOpString<unsigned int, unsigned long>( 519 const unsigned int&, const unsigned long&, const char* names); 520extern template BASE_EXPORT 521std::string* MakeCheckOpString<std::string, std::string>( 522 const std::string&, const std::string&, const char* name); 523#endif 524 525// Helper functions for CHECK_OP macro. 526// The (int, int) specialization works around the issue that the compiler 527// will not instantiate the template version of the function on values of 528// unnamed enum type - see comment below. 529#define DEFINE_CHECK_OP_IMPL(name, op) \ 530 template <class t1, class t2> \ 531 inline std::string* Check##name##Impl(const t1& v1, const t2& v2, \ 532 const char* names) { \ 533 if (v1 op v2) return NULL; \ 534 else return MakeCheckOpString(v1, v2, names); \ 535 } \ 536 inline std::string* Check##name##Impl(int v1, int v2, const char* names) { \ 537 if (v1 op v2) return NULL; \ 538 else return MakeCheckOpString(v1, v2, names); \ 539 } 540DEFINE_CHECK_OP_IMPL(EQ, ==) 541DEFINE_CHECK_OP_IMPL(NE, !=) 542DEFINE_CHECK_OP_IMPL(LE, <=) 543DEFINE_CHECK_OP_IMPL(LT, < ) 544DEFINE_CHECK_OP_IMPL(GE, >=) 545DEFINE_CHECK_OP_IMPL(GT, > ) 546#undef DEFINE_CHECK_OP_IMPL 547 548#define CHECK_EQ(val1, val2) CHECK_OP(EQ, ==, val1, val2) 549#define CHECK_NE(val1, val2) CHECK_OP(NE, !=, val1, val2) 550#define CHECK_LE(val1, val2) CHECK_OP(LE, <=, val1, val2) 551#define CHECK_LT(val1, val2) CHECK_OP(LT, < , val1, val2) 552#define CHECK_GE(val1, val2) CHECK_OP(GE, >=, val1, val2) 553#define CHECK_GT(val1, val2) CHECK_OP(GT, > , val1, val2) 554 555#if defined(NDEBUG) 556#define ENABLE_DLOG 0 557#else 558#define ENABLE_DLOG 1 559#endif 560 561#if defined(NDEBUG) && !defined(DCHECK_ALWAYS_ON) 562#define DCHECK_IS_ON 0 563#else 564#define DCHECK_IS_ON 1 565#endif 566 567// Definitions for DLOG et al. 568 569#if ENABLE_DLOG 570 571#define DLOG_IS_ON(severity) LOG_IS_ON(severity) 572#define DLOG_IF(severity, condition) LOG_IF(severity, condition) 573#define DLOG_ASSERT(condition) LOG_ASSERT(condition) 574#define DPLOG_IF(severity, condition) PLOG_IF(severity, condition) 575#define DVLOG_IF(verboselevel, condition) VLOG_IF(verboselevel, condition) 576#define DVPLOG_IF(verboselevel, condition) VPLOG_IF(verboselevel, condition) 577 578#else // ENABLE_DLOG 579 580// If ENABLE_DLOG is off, we want to avoid emitting any references to 581// |condition| (which may reference a variable defined only if NDEBUG 582// is not defined). Contrast this with DCHECK et al., which has 583// different behavior. 584 585#define DLOG_IS_ON(severity) false 586#define DLOG_IF(severity, condition) EAT_STREAM_PARAMETERS 587#define DLOG_ASSERT(condition) EAT_STREAM_PARAMETERS 588#define DPLOG_IF(severity, condition) EAT_STREAM_PARAMETERS 589#define DVLOG_IF(verboselevel, condition) EAT_STREAM_PARAMETERS 590#define DVPLOG_IF(verboselevel, condition) EAT_STREAM_PARAMETERS 591 592#endif // ENABLE_DLOG 593 594// DEBUG_MODE is for uses like 595// if (DEBUG_MODE) foo.CheckThatFoo(); 596// instead of 597// #ifndef NDEBUG 598// foo.CheckThatFoo(); 599// #endif 600// 601// We tie its state to ENABLE_DLOG. 602enum { DEBUG_MODE = ENABLE_DLOG }; 603 604#undef ENABLE_DLOG 605 606#define DLOG(severity) \ 607 LAZY_STREAM(LOG_STREAM(severity), DLOG_IS_ON(severity)) 608 609#define DPLOG(severity) \ 610 LAZY_STREAM(PLOG_STREAM(severity), DLOG_IS_ON(severity)) 611 612#define DVLOG(verboselevel) DVLOG_IF(verboselevel, VLOG_IS_ON(verboselevel)) 613 614#define DVPLOG(verboselevel) DVPLOG_IF(verboselevel, VLOG_IS_ON(verboselevel)) 615 616// TODO(vitalybuka): following should be removed and replaced with PLOG. 617#if defined(OS_WIN) 618#define LOG_GETLASTERROR(severity) PLOG(severity) 619#define DLOG_GETLASTERROR(severity) DPLOG(severity) 620#elif defined(OS_POSIX) 621#define LOG_ERRNO(severity) PLOG(severity) 622#define DLOG_ERRNO(severity) DPLOG(severity) 623#endif 624 625// Definitions for DCHECK et al. 626 627#if DCHECK_IS_ON 628 629#define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \ 630 COMPACT_GOOGLE_LOG_EX_FATAL(ClassName , ##__VA_ARGS__) 631#define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_FATAL 632const LogSeverity LOG_DCHECK = LOG_FATAL; 633 634#else // DCHECK_IS_ON 635 636// These are just dummy values. 637#define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \ 638 COMPACT_GOOGLE_LOG_EX_INFO(ClassName , ##__VA_ARGS__) 639#define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_INFO 640const LogSeverity LOG_DCHECK = LOG_INFO; 641 642#endif // DCHECK_IS_ON 643 644// DCHECK et al. make sure to reference |condition| regardless of 645// whether DCHECKs are enabled; this is so that we don't get unused 646// variable warnings if the only use of a variable is in a DCHECK. 647// This behavior is different from DLOG_IF et al. 648 649#define DCHECK(condition) \ 650 LAZY_STREAM(LOG_STREAM(DCHECK), DCHECK_IS_ON && !(condition)) \ 651 << "Check failed: " #condition ". " 652 653#define DPCHECK(condition) \ 654 LAZY_STREAM(PLOG_STREAM(DCHECK), DCHECK_IS_ON && !(condition)) \ 655 << "Check failed: " #condition ". " 656 657// Helper macro for binary operators. 658// Don't use this macro directly in your code, use DCHECK_EQ et al below. 659#define DCHECK_OP(name, op, val1, val2) \ 660 if (DCHECK_IS_ON) \ 661 if (std::string* _result = \ 662 logging::Check##name##Impl((val1), (val2), \ 663 #val1 " " #op " " #val2)) \ 664 logging::LogMessage( \ 665 __FILE__, __LINE__, ::logging::LOG_DCHECK, \ 666 _result).stream() 667 668// Equality/Inequality checks - compare two values, and log a 669// LOG_DCHECK message including the two values when the result is not 670// as expected. The values must have operator<<(ostream, ...) 671// defined. 672// 673// You may append to the error message like so: 674// DCHECK_NE(1, 2) << ": The world must be ending!"; 675// 676// We are very careful to ensure that each argument is evaluated exactly 677// once, and that anything which is legal to pass as a function argument is 678// legal here. In particular, the arguments may be temporary expressions 679// which will end up being destroyed at the end of the apparent statement, 680// for example: 681// DCHECK_EQ(string("abc")[1], 'b'); 682// 683// WARNING: These may not compile correctly if one of the arguments is a pointer 684// and the other is NULL. To work around this, simply static_cast NULL to the 685// type of the desired pointer. 686 687#define DCHECK_EQ(val1, val2) DCHECK_OP(EQ, ==, val1, val2) 688#define DCHECK_NE(val1, val2) DCHECK_OP(NE, !=, val1, val2) 689#define DCHECK_LE(val1, val2) DCHECK_OP(LE, <=, val1, val2) 690#define DCHECK_LT(val1, val2) DCHECK_OP(LT, < , val1, val2) 691#define DCHECK_GE(val1, val2) DCHECK_OP(GE, >=, val1, val2) 692#define DCHECK_GT(val1, val2) DCHECK_OP(GT, > , val1, val2) 693 694#if defined(NDEBUG) && defined(OS_CHROMEOS) 695#define NOTREACHED() LOG(ERROR) << "NOTREACHED() hit in " << \ 696 __FUNCTION__ << ". " 697#else 698#define NOTREACHED() DCHECK(false) 699#endif 700 701// Redefine the standard assert to use our nice log files 702#undef assert 703#define assert(x) DLOG_ASSERT(x) 704 705// This class more or less represents a particular log message. You 706// create an instance of LogMessage and then stream stuff to it. 707// When you finish streaming to it, ~LogMessage is called and the 708// full message gets streamed to the appropriate destination. 709// 710// You shouldn't actually use LogMessage's constructor to log things, 711// though. You should use the LOG() macro (and variants thereof) 712// above. 713class BASE_EXPORT LogMessage { 714 public: 715 LogMessage(const char* file, int line, LogSeverity severity, int ctr); 716 717 // Two special constructors that generate reduced amounts of code at 718 // LOG call sites for common cases. 719 // 720 // Used for LOG(INFO): Implied are: 721 // severity = LOG_INFO, ctr = 0 722 // 723 // Using this constructor instead of the more complex constructor above 724 // saves a couple of bytes per call site. 725 LogMessage(const char* file, int line); 726 727 // Used for LOG(severity) where severity != INFO. Implied 728 // are: ctr = 0 729 // 730 // Using this constructor instead of the more complex constructor above 731 // saves a couple of bytes per call site. 732 LogMessage(const char* file, int line, LogSeverity severity); 733 734 // A special constructor used for check failures. Takes ownership 735 // of the given string. 736 // Implied severity = LOG_FATAL 737 LogMessage(const char* file, int line, std::string* result); 738 739 // A special constructor used for check failures, with the option to 740 // specify severity. Takes ownership of the given string. 741 LogMessage(const char* file, int line, LogSeverity severity, 742 std::string* result); 743 744 ~LogMessage(); 745 746 std::ostream& stream() { return stream_; } 747 748 private: 749 void Init(const char* file, int line); 750 751 LogSeverity severity_; 752 std::ostringstream stream_; 753 size_t message_start_; // Offset of the start of the message (past prefix 754 // info). 755 // The file and line information passed in to the constructor. 756 const char* file_; 757 const int line_; 758 759#if defined(OS_WIN) 760 // Stores the current value of GetLastError in the constructor and restores 761 // it in the destructor by calling SetLastError. 762 // This is useful since the LogMessage class uses a lot of Win32 calls 763 // that will lose the value of GLE and the code that called the log function 764 // will have lost the thread error value when the log call returns. 765 class SaveLastError { 766 public: 767 SaveLastError(); 768 ~SaveLastError(); 769 770 unsigned long get_error() const { return last_error_; } 771 772 protected: 773 unsigned long last_error_; 774 }; 775 776 SaveLastError last_error_; 777#endif 778 779 DISALLOW_COPY_AND_ASSIGN(LogMessage); 780}; 781 782// A non-macro interface to the log facility; (useful 783// when the logging level is not a compile-time constant). 784inline void LogAtLevel(int const log_level, std::string const &msg) { 785 LogMessage(__FILE__, __LINE__, log_level).stream() << msg; 786} 787 788// This class is used to explicitly ignore values in the conditional 789// logging macros. This avoids compiler warnings like "value computed 790// is not used" and "statement has no effect". 791class LogMessageVoidify { 792 public: 793 LogMessageVoidify() { } 794 // This has to be an operator with a precedence lower than << but 795 // higher than ?: 796 void operator&(std::ostream&) { } 797}; 798 799#if defined(OS_WIN) 800typedef unsigned long SystemErrorCode; 801#elif defined(OS_POSIX) 802typedef int SystemErrorCode; 803#endif 804 805// Alias for ::GetLastError() on Windows and errno on POSIX. Avoids having to 806// pull in windows.h just for GetLastError() and DWORD. 807BASE_EXPORT SystemErrorCode GetLastSystemErrorCode(); 808BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code); 809 810#if defined(OS_WIN) 811// Appends a formatted system message of the GetLastError() type. 812class BASE_EXPORT Win32ErrorLogMessage { 813 public: 814 Win32ErrorLogMessage(const char* file, 815 int line, 816 LogSeverity severity, 817 SystemErrorCode err); 818 819 // Appends the error message before destructing the encapsulated class. 820 ~Win32ErrorLogMessage(); 821 822 std::ostream& stream() { return log_message_.stream(); } 823 824 private: 825 SystemErrorCode err_; 826 LogMessage log_message_; 827 828 DISALLOW_COPY_AND_ASSIGN(Win32ErrorLogMessage); 829}; 830#elif defined(OS_POSIX) 831// Appends a formatted system message of the errno type 832class BASE_EXPORT ErrnoLogMessage { 833 public: 834 ErrnoLogMessage(const char* file, 835 int line, 836 LogSeverity severity, 837 SystemErrorCode err); 838 839 // Appends the error message before destructing the encapsulated class. 840 ~ErrnoLogMessage(); 841 842 std::ostream& stream() { return log_message_.stream(); } 843 844 private: 845 SystemErrorCode err_; 846 LogMessage log_message_; 847 848 DISALLOW_COPY_AND_ASSIGN(ErrnoLogMessage); 849}; 850#endif // OS_WIN 851 852// Closes the log file explicitly if open. 853// NOTE: Since the log file is opened as necessary by the action of logging 854// statements, there's no guarantee that it will stay closed 855// after this call. 856BASE_EXPORT void CloseLogFile(); 857 858// Async signal safe logging mechanism. 859BASE_EXPORT void RawLog(int level, const char* message); 860 861#define RAW_LOG(level, message) logging::RawLog(logging::LOG_ ## level, message) 862 863#define RAW_CHECK(condition) \ 864 do { \ 865 if (!(condition)) \ 866 logging::RawLog(logging::LOG_FATAL, "Check failed: " #condition "\n"); \ 867 } while (0) 868 869#if defined(OS_WIN) 870// Returns the default log file path. 871BASE_EXPORT std::wstring GetLogFileFullPath(); 872#endif 873 874} // namespace logging 875 876// These functions are provided as a convenience for logging, which is where we 877// use streams (it is against Google style to use streams in other places). It 878// is designed to allow you to emit non-ASCII Unicode strings to the log file, 879// which is normally ASCII. It is relatively slow, so try not to use it for 880// common cases. Non-ASCII characters will be converted to UTF-8 by these 881// operators. 882BASE_EXPORT std::ostream& operator<<(std::ostream& out, const wchar_t* wstr); 883inline std::ostream& operator<<(std::ostream& out, const std::wstring& wstr) { 884 return out << wstr.c_str(); 885} 886 887// The NOTIMPLEMENTED() macro annotates codepaths which have 888// not been implemented yet. 889// 890// The implementation of this macro is controlled by NOTIMPLEMENTED_POLICY: 891// 0 -- Do nothing (stripped by compiler) 892// 1 -- Warn at compile time 893// 2 -- Fail at compile time 894// 3 -- Fail at runtime (DCHECK) 895// 4 -- [default] LOG(ERROR) at runtime 896// 5 -- LOG(ERROR) at runtime, only once per call-site 897 898#ifndef NOTIMPLEMENTED_POLICY 899#if defined(OS_ANDROID) && defined(OFFICIAL_BUILD) 900#define NOTIMPLEMENTED_POLICY 0 901#else 902// Select default policy: LOG(ERROR) 903#define NOTIMPLEMENTED_POLICY 4 904#endif 905#endif 906 907#if defined(COMPILER_GCC) 908// On Linux, with GCC, we can use __PRETTY_FUNCTION__ to get the demangled name 909// of the current function in the NOTIMPLEMENTED message. 910#define NOTIMPLEMENTED_MSG "Not implemented reached in " << __PRETTY_FUNCTION__ 911#else 912#define NOTIMPLEMENTED_MSG "NOT IMPLEMENTED" 913#endif 914 915#if NOTIMPLEMENTED_POLICY == 0 916#define NOTIMPLEMENTED() EAT_STREAM_PARAMETERS 917#elif NOTIMPLEMENTED_POLICY == 1 918// TODO, figure out how to generate a warning 919#define NOTIMPLEMENTED() COMPILE_ASSERT(false, NOT_IMPLEMENTED) 920#elif NOTIMPLEMENTED_POLICY == 2 921#define NOTIMPLEMENTED() COMPILE_ASSERT(false, NOT_IMPLEMENTED) 922#elif NOTIMPLEMENTED_POLICY == 3 923#define NOTIMPLEMENTED() NOTREACHED() 924#elif NOTIMPLEMENTED_POLICY == 4 925#define NOTIMPLEMENTED() LOG(ERROR) << NOTIMPLEMENTED_MSG 926#elif NOTIMPLEMENTED_POLICY == 5 927#define NOTIMPLEMENTED() do {\ 928 static bool logged_once = false;\ 929 LOG_IF(ERROR, !logged_once) << NOTIMPLEMENTED_MSG;\ 930 logged_once = true;\ 931} while(0);\ 932EAT_STREAM_PARAMETERS 933#endif 934 935#endif // BASE_LOGGING_H_ 936