logging.h revision a1401311d1ab56c4ed0a474bd38c108f75cb0cd9
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 LOG_GETLASTERROR_STREAM(severity) \ 430 COMPACT_GOOGLE_LOG_EX_ ## severity(Win32ErrorLogMessage, \ 431 ::logging::GetLastSystemErrorCode()).stream() 432#define LOG_GETLASTERROR(severity) \ 433 LAZY_STREAM(LOG_GETLASTERROR_STREAM(severity), LOG_IS_ON(severity)) 434#define LOG_GETLASTERROR_MODULE_STREAM(severity, module) \ 435 COMPACT_GOOGLE_LOG_EX_ ## severity(Win32ErrorLogMessage, \ 436 ::logging::GetLastSystemErrorCode(), module).stream() 437#define LOG_GETLASTERROR_MODULE(severity, module) \ 438 LAZY_STREAM(LOG_GETLASTERROR_STREAM(severity, module), \ 439 LOG_IS_ON(severity)) 440// PLOG_STREAM is used by PLOG, which is the usual error logging macro 441// for each platform. 442#define PLOG_STREAM(severity) LOG_GETLASTERROR_STREAM(severity) 443#elif defined(OS_POSIX) 444#define LOG_ERRNO_STREAM(severity) \ 445 COMPACT_GOOGLE_LOG_EX_ ## severity(ErrnoLogMessage, \ 446 ::logging::GetLastSystemErrorCode()).stream() 447#define LOG_ERRNO(severity) \ 448 LAZY_STREAM(LOG_ERRNO_STREAM(severity), LOG_IS_ON(severity)) 449// PLOG_STREAM is used by PLOG, which is the usual error logging macro 450// for each platform. 451#define PLOG_STREAM(severity) LOG_ERRNO_STREAM(severity) 452#endif 453 454#define PLOG(severity) \ 455 LAZY_STREAM(PLOG_STREAM(severity), LOG_IS_ON(severity)) 456 457#define PLOG_IF(severity, condition) \ 458 LAZY_STREAM(PLOG_STREAM(severity), LOG_IS_ON(severity) && (condition)) 459 460// The actual stream used isn't important. 461#define EAT_STREAM_PARAMETERS \ 462 true ? (void) 0 : ::logging::LogMessageVoidify() & LOG_STREAM(FATAL) 463 464// CHECK dies with a fatal error if condition is not true. It is *not* 465// controlled by NDEBUG, so the check will be executed regardless of 466// compilation mode. 467// 468// We make sure CHECK et al. always evaluates their arguments, as 469// doing CHECK(FunctionWithSideEffect()) is a common idiom. 470 471#if defined(OFFICIAL_BUILD) && defined(NDEBUG) 472 473// Make all CHECK functions discard their log strings to reduce code 474// bloat for official release builds. 475 476// TODO(akalin): This would be more valuable if there were some way to 477// remove BreakDebugger() from the backtrace, perhaps by turning it 478// into a macro (like __debugbreak() on Windows). 479#define CHECK(condition) \ 480 !(condition) ? ::base::debug::BreakDebugger() : EAT_STREAM_PARAMETERS 481 482#define PCHECK(condition) CHECK(condition) 483 484#define CHECK_OP(name, op, val1, val2) CHECK((val1) op (val2)) 485 486#else 487 488#define CHECK(condition) \ 489 LAZY_STREAM(LOG_STREAM(FATAL), !(condition)) \ 490 << "Check failed: " #condition ". " 491 492#define PCHECK(condition) \ 493 LAZY_STREAM(PLOG_STREAM(FATAL), !(condition)) \ 494 << "Check failed: " #condition ". " 495 496// Helper macro for binary operators. 497// Don't use this macro directly in your code, use CHECK_EQ et al below. 498// 499// TODO(akalin): Rewrite this so that constructs like if (...) 500// CHECK_EQ(...) else { ... } work properly. 501#define CHECK_OP(name, op, val1, val2) \ 502 if (std::string* _result = \ 503 logging::Check##name##Impl((val1), (val2), \ 504 #val1 " " #op " " #val2)) \ 505 logging::LogMessage(__FILE__, __LINE__, _result).stream() 506 507#endif 508 509// Build the error message string. This is separate from the "Impl" 510// function template because it is not performance critical and so can 511// be out of line, while the "Impl" code should be inline. Caller 512// takes ownership of the returned string. 513template<class t1, class t2> 514std::string* MakeCheckOpString(const t1& v1, const t2& v2, const char* names) { 515 std::ostringstream ss; 516 ss << names << " (" << v1 << " vs. " << v2 << ")"; 517 std::string* msg = new std::string(ss.str()); 518 return msg; 519} 520 521// MSVC doesn't like complex extern templates and DLLs. 522#if !defined(COMPILER_MSVC) 523// Commonly used instantiations of MakeCheckOpString<>. Explicitly instantiated 524// in logging.cc. 525extern template BASE_EXPORT std::string* MakeCheckOpString<int, int>( 526 const int&, const int&, const char* names); 527extern template BASE_EXPORT 528std::string* MakeCheckOpString<unsigned long, unsigned long>( 529 const unsigned long&, const unsigned long&, const char* names); 530extern template BASE_EXPORT 531std::string* MakeCheckOpString<unsigned long, unsigned int>( 532 const unsigned long&, const unsigned int&, const char* names); 533extern template BASE_EXPORT 534std::string* MakeCheckOpString<unsigned int, unsigned long>( 535 const unsigned int&, const unsigned long&, const char* names); 536extern template BASE_EXPORT 537std::string* MakeCheckOpString<std::string, std::string>( 538 const std::string&, const std::string&, const char* name); 539#endif 540 541// Helper functions for CHECK_OP macro. 542// The (int, int) specialization works around the issue that the compiler 543// will not instantiate the template version of the function on values of 544// unnamed enum type - see comment below. 545#define DEFINE_CHECK_OP_IMPL(name, op) \ 546 template <class t1, class t2> \ 547 inline std::string* Check##name##Impl(const t1& v1, const t2& v2, \ 548 const char* names) { \ 549 if (v1 op v2) return NULL; \ 550 else return MakeCheckOpString(v1, v2, names); \ 551 } \ 552 inline std::string* Check##name##Impl(int v1, int v2, const char* names) { \ 553 if (v1 op v2) return NULL; \ 554 else return MakeCheckOpString(v1, v2, names); \ 555 } 556DEFINE_CHECK_OP_IMPL(EQ, ==) 557DEFINE_CHECK_OP_IMPL(NE, !=) 558DEFINE_CHECK_OP_IMPL(LE, <=) 559DEFINE_CHECK_OP_IMPL(LT, < ) 560DEFINE_CHECK_OP_IMPL(GE, >=) 561DEFINE_CHECK_OP_IMPL(GT, > ) 562#undef DEFINE_CHECK_OP_IMPL 563 564#define CHECK_EQ(val1, val2) CHECK_OP(EQ, ==, val1, val2) 565#define CHECK_NE(val1, val2) CHECK_OP(NE, !=, val1, val2) 566#define CHECK_LE(val1, val2) CHECK_OP(LE, <=, val1, val2) 567#define CHECK_LT(val1, val2) CHECK_OP(LT, < , val1, val2) 568#define CHECK_GE(val1, val2) CHECK_OP(GE, >=, val1, val2) 569#define CHECK_GT(val1, val2) CHECK_OP(GT, > , val1, val2) 570 571#if defined(NDEBUG) 572#define ENABLE_DLOG 0 573#else 574#define ENABLE_DLOG 1 575#endif 576 577#if defined(NDEBUG) && !defined(DCHECK_ALWAYS_ON) 578#define DCHECK_IS_ON 0 579#else 580#define DCHECK_IS_ON 1 581#endif 582 583// Definitions for DLOG et al. 584 585#if ENABLE_DLOG 586 587#define DLOG_IS_ON(severity) LOG_IS_ON(severity) 588#define DLOG_IF(severity, condition) LOG_IF(severity, condition) 589#define DLOG_ASSERT(condition) LOG_ASSERT(condition) 590#define DPLOG_IF(severity, condition) PLOG_IF(severity, condition) 591#define DVLOG_IF(verboselevel, condition) VLOG_IF(verboselevel, condition) 592#define DVPLOG_IF(verboselevel, condition) VPLOG_IF(verboselevel, condition) 593 594#else // ENABLE_DLOG 595 596// If ENABLE_DLOG is off, we want to avoid emitting any references to 597// |condition| (which may reference a variable defined only if NDEBUG 598// is not defined). Contrast this with DCHECK et al., which has 599// different behavior. 600 601#define DLOG_IS_ON(severity) false 602#define DLOG_IF(severity, condition) EAT_STREAM_PARAMETERS 603#define DLOG_ASSERT(condition) EAT_STREAM_PARAMETERS 604#define DPLOG_IF(severity, condition) EAT_STREAM_PARAMETERS 605#define DVLOG_IF(verboselevel, condition) EAT_STREAM_PARAMETERS 606#define DVPLOG_IF(verboselevel, condition) EAT_STREAM_PARAMETERS 607 608#endif // ENABLE_DLOG 609 610// DEBUG_MODE is for uses like 611// if (DEBUG_MODE) foo.CheckThatFoo(); 612// instead of 613// #ifndef NDEBUG 614// foo.CheckThatFoo(); 615// #endif 616// 617// We tie its state to ENABLE_DLOG. 618enum { DEBUG_MODE = ENABLE_DLOG }; 619 620#undef ENABLE_DLOG 621 622#define DLOG(severity) \ 623 LAZY_STREAM(LOG_STREAM(severity), DLOG_IS_ON(severity)) 624 625#if defined(OS_WIN) 626#define DLOG_GETLASTERROR(severity) \ 627 LAZY_STREAM(LOG_GETLASTERROR_STREAM(severity), DLOG_IS_ON(severity)) 628#define DLOG_GETLASTERROR_MODULE(severity, module) \ 629 LAZY_STREAM(LOG_GETLASTERROR_STREAM(severity, module), \ 630 DLOG_IS_ON(severity)) 631#elif defined(OS_POSIX) 632#define DLOG_ERRNO(severity) \ 633 LAZY_STREAM(LOG_ERRNO_STREAM(severity), DLOG_IS_ON(severity)) 634#endif 635 636#define DPLOG(severity) \ 637 LAZY_STREAM(PLOG_STREAM(severity), DLOG_IS_ON(severity)) 638 639#define DVLOG(verboselevel) DVLOG_IF(verboselevel, VLOG_IS_ON(verboselevel)) 640 641#define DVPLOG(verboselevel) DVPLOG_IF(verboselevel, VLOG_IS_ON(verboselevel)) 642 643// Definitions for DCHECK et al. 644 645#if DCHECK_IS_ON 646 647#define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \ 648 COMPACT_GOOGLE_LOG_EX_FATAL(ClassName , ##__VA_ARGS__) 649#define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_FATAL 650const LogSeverity LOG_DCHECK = LOG_FATAL; 651 652#else // DCHECK_IS_ON 653 654// These are just dummy values. 655#define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \ 656 COMPACT_GOOGLE_LOG_EX_INFO(ClassName , ##__VA_ARGS__) 657#define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_INFO 658const LogSeverity LOG_DCHECK = LOG_INFO; 659 660#endif // DCHECK_IS_ON 661 662// DCHECK et al. make sure to reference |condition| regardless of 663// whether DCHECKs are enabled; this is so that we don't get unused 664// variable warnings if the only use of a variable is in a DCHECK. 665// This behavior is different from DLOG_IF et al. 666 667#define DCHECK(condition) \ 668 LAZY_STREAM(LOG_STREAM(DCHECK), DCHECK_IS_ON && !(condition)) \ 669 << "Check failed: " #condition ". " 670 671#define DPCHECK(condition) \ 672 LAZY_STREAM(PLOG_STREAM(DCHECK), DCHECK_IS_ON && !(condition)) \ 673 << "Check failed: " #condition ". " 674 675// Helper macro for binary operators. 676// Don't use this macro directly in your code, use DCHECK_EQ et al below. 677#define DCHECK_OP(name, op, val1, val2) \ 678 if (DCHECK_IS_ON) \ 679 if (std::string* _result = \ 680 logging::Check##name##Impl((val1), (val2), \ 681 #val1 " " #op " " #val2)) \ 682 logging::LogMessage( \ 683 __FILE__, __LINE__, ::logging::LOG_DCHECK, \ 684 _result).stream() 685 686// Equality/Inequality checks - compare two values, and log a 687// LOG_DCHECK message including the two values when the result is not 688// as expected. The values must have operator<<(ostream, ...) 689// defined. 690// 691// You may append to the error message like so: 692// DCHECK_NE(1, 2) << ": The world must be ending!"; 693// 694// We are very careful to ensure that each argument is evaluated exactly 695// once, and that anything which is legal to pass as a function argument is 696// legal here. In particular, the arguments may be temporary expressions 697// which will end up being destroyed at the end of the apparent statement, 698// for example: 699// DCHECK_EQ(string("abc")[1], 'b'); 700// 701// WARNING: These may not compile correctly if one of the arguments is a pointer 702// and the other is NULL. To work around this, simply static_cast NULL to the 703// type of the desired pointer. 704 705#define DCHECK_EQ(val1, val2) DCHECK_OP(EQ, ==, val1, val2) 706#define DCHECK_NE(val1, val2) DCHECK_OP(NE, !=, val1, val2) 707#define DCHECK_LE(val1, val2) DCHECK_OP(LE, <=, val1, val2) 708#define DCHECK_LT(val1, val2) DCHECK_OP(LT, < , val1, val2) 709#define DCHECK_GE(val1, val2) DCHECK_OP(GE, >=, val1, val2) 710#define DCHECK_GT(val1, val2) DCHECK_OP(GT, > , val1, val2) 711 712#if defined(NDEBUG) && defined(OS_CHROMEOS) 713#define NOTREACHED() LOG(ERROR) << "NOTREACHED() hit in " << \ 714 __FUNCTION__ << ". " 715#else 716#define NOTREACHED() DCHECK(false) 717#endif 718 719// Redefine the standard assert to use our nice log files 720#undef assert 721#define assert(x) DLOG_ASSERT(x) 722 723// This class more or less represents a particular log message. You 724// create an instance of LogMessage and then stream stuff to it. 725// When you finish streaming to it, ~LogMessage is called and the 726// full message gets streamed to the appropriate destination. 727// 728// You shouldn't actually use LogMessage's constructor to log things, 729// though. You should use the LOG() macro (and variants thereof) 730// above. 731class BASE_EXPORT LogMessage { 732 public: 733 LogMessage(const char* file, int line, LogSeverity severity, int ctr); 734 735 // Two special constructors that generate reduced amounts of code at 736 // LOG call sites for common cases. 737 // 738 // Used for LOG(INFO): Implied are: 739 // severity = LOG_INFO, ctr = 0 740 // 741 // Using this constructor instead of the more complex constructor above 742 // saves a couple of bytes per call site. 743 LogMessage(const char* file, int line); 744 745 // Used for LOG(severity) where severity != INFO. Implied 746 // are: ctr = 0 747 // 748 // Using this constructor instead of the more complex constructor above 749 // saves a couple of bytes per call site. 750 LogMessage(const char* file, int line, LogSeverity severity); 751 752 // A special constructor used for check failures. Takes ownership 753 // of the given string. 754 // Implied severity = LOG_FATAL 755 LogMessage(const char* file, int line, std::string* result); 756 757 // A special constructor used for check failures, with the option to 758 // specify severity. Takes ownership of the given string. 759 LogMessage(const char* file, int line, LogSeverity severity, 760 std::string* result); 761 762 ~LogMessage(); 763 764 std::ostream& stream() { return stream_; } 765 766 private: 767 void Init(const char* file, int line); 768 769 LogSeverity severity_; 770 std::ostringstream stream_; 771 size_t message_start_; // Offset of the start of the message (past prefix 772 // info). 773 // The file and line information passed in to the constructor. 774 const char* file_; 775 const int line_; 776 777#if defined(OS_WIN) 778 // Stores the current value of GetLastError in the constructor and restores 779 // it in the destructor by calling SetLastError. 780 // This is useful since the LogMessage class uses a lot of Win32 calls 781 // that will lose the value of GLE and the code that called the log function 782 // will have lost the thread error value when the log call returns. 783 class SaveLastError { 784 public: 785 SaveLastError(); 786 ~SaveLastError(); 787 788 unsigned long get_error() const { return last_error_; } 789 790 protected: 791 unsigned long last_error_; 792 }; 793 794 SaveLastError last_error_; 795#endif 796 797 DISALLOW_COPY_AND_ASSIGN(LogMessage); 798}; 799 800// A non-macro interface to the log facility; (useful 801// when the logging level is not a compile-time constant). 802inline void LogAtLevel(int const log_level, std::string const &msg) { 803 LogMessage(__FILE__, __LINE__, log_level).stream() << msg; 804} 805 806// This class is used to explicitly ignore values in the conditional 807// logging macros. This avoids compiler warnings like "value computed 808// is not used" and "statement has no effect". 809class LogMessageVoidify { 810 public: 811 LogMessageVoidify() { } 812 // This has to be an operator with a precedence lower than << but 813 // higher than ?: 814 void operator&(std::ostream&) { } 815}; 816 817#if defined(OS_WIN) 818typedef unsigned long SystemErrorCode; 819#elif defined(OS_POSIX) 820typedef int SystemErrorCode; 821#endif 822 823// Alias for ::GetLastError() on Windows and errno on POSIX. Avoids having to 824// pull in windows.h just for GetLastError() and DWORD. 825BASE_EXPORT SystemErrorCode GetLastSystemErrorCode(); 826 827#if defined(OS_WIN) 828// Appends a formatted system message of the GetLastError() type. 829class BASE_EXPORT Win32ErrorLogMessage { 830 public: 831 Win32ErrorLogMessage(const char* file, 832 int line, 833 LogSeverity severity, 834 SystemErrorCode err, 835 const char* module); 836 837 Win32ErrorLogMessage(const char* file, 838 int line, 839 LogSeverity severity, 840 SystemErrorCode err); 841 842 // Appends the error message before destructing the encapsulated class. 843 ~Win32ErrorLogMessage(); 844 845 std::ostream& stream() { return log_message_.stream(); } 846 847 private: 848 SystemErrorCode err_; 849 // Optional name of the module defining the error. 850 const char* module_; 851 LogMessage log_message_; 852 853 DISALLOW_COPY_AND_ASSIGN(Win32ErrorLogMessage); 854}; 855#elif defined(OS_POSIX) 856// Appends a formatted system message of the errno type 857class BASE_EXPORT ErrnoLogMessage { 858 public: 859 ErrnoLogMessage(const char* file, 860 int line, 861 LogSeverity severity, 862 SystemErrorCode err); 863 864 // Appends the error message before destructing the encapsulated class. 865 ~ErrnoLogMessage(); 866 867 std::ostream& stream() { return log_message_.stream(); } 868 869 private: 870 SystemErrorCode err_; 871 LogMessage log_message_; 872 873 DISALLOW_COPY_AND_ASSIGN(ErrnoLogMessage); 874}; 875#endif // OS_WIN 876 877// Closes the log file explicitly if open. 878// NOTE: Since the log file is opened as necessary by the action of logging 879// statements, there's no guarantee that it will stay closed 880// after this call. 881BASE_EXPORT void CloseLogFile(); 882 883// Async signal safe logging mechanism. 884BASE_EXPORT void RawLog(int level, const char* message); 885 886#define RAW_LOG(level, message) logging::RawLog(logging::LOG_ ## level, message) 887 888#define RAW_CHECK(condition) \ 889 do { \ 890 if (!(condition)) \ 891 logging::RawLog(logging::LOG_FATAL, "Check failed: " #condition "\n"); \ 892 } while (0) 893 894#if defined(OS_WIN) 895// Returns the default log file path. 896BASE_EXPORT std::wstring GetLogFileFullPath(); 897#endif 898 899} // namespace logging 900 901// These functions are provided as a convenience for logging, which is where we 902// use streams (it is against Google style to use streams in other places). It 903// is designed to allow you to emit non-ASCII Unicode strings to the log file, 904// which is normally ASCII. It is relatively slow, so try not to use it for 905// common cases. Non-ASCII characters will be converted to UTF-8 by these 906// operators. 907BASE_EXPORT std::ostream& operator<<(std::ostream& out, const wchar_t* wstr); 908inline std::ostream& operator<<(std::ostream& out, const std::wstring& wstr) { 909 return out << wstr.c_str(); 910} 911 912// The NOTIMPLEMENTED() macro annotates codepaths which have 913// not been implemented yet. 914// 915// The implementation of this macro is controlled by NOTIMPLEMENTED_POLICY: 916// 0 -- Do nothing (stripped by compiler) 917// 1 -- Warn at compile time 918// 2 -- Fail at compile time 919// 3 -- Fail at runtime (DCHECK) 920// 4 -- [default] LOG(ERROR) at runtime 921// 5 -- LOG(ERROR) at runtime, only once per call-site 922 923#ifndef NOTIMPLEMENTED_POLICY 924#if defined(OS_ANDROID) && defined(OFFICIAL_BUILD) 925#define NOTIMPLEMENTED_POLICY 0 926#else 927// Select default policy: LOG(ERROR) 928#define NOTIMPLEMENTED_POLICY 4 929#endif 930#endif 931 932#if defined(COMPILER_GCC) 933// On Linux, with GCC, we can use __PRETTY_FUNCTION__ to get the demangled name 934// of the current function in the NOTIMPLEMENTED message. 935#define NOTIMPLEMENTED_MSG "Not implemented reached in " << __PRETTY_FUNCTION__ 936#else 937#define NOTIMPLEMENTED_MSG "NOT IMPLEMENTED" 938#endif 939 940#if NOTIMPLEMENTED_POLICY == 0 941#define NOTIMPLEMENTED() EAT_STREAM_PARAMETERS 942#elif NOTIMPLEMENTED_POLICY == 1 943// TODO, figure out how to generate a warning 944#define NOTIMPLEMENTED() COMPILE_ASSERT(false, NOT_IMPLEMENTED) 945#elif NOTIMPLEMENTED_POLICY == 2 946#define NOTIMPLEMENTED() COMPILE_ASSERT(false, NOT_IMPLEMENTED) 947#elif NOTIMPLEMENTED_POLICY == 3 948#define NOTIMPLEMENTED() NOTREACHED() 949#elif NOTIMPLEMENTED_POLICY == 4 950#define NOTIMPLEMENTED() LOG(ERROR) << NOTIMPLEMENTED_MSG 951#elif NOTIMPLEMENTED_POLICY == 5 952#define NOTIMPLEMENTED() do {\ 953 static bool logged_once = false;\ 954 LOG_IF(ERROR, !logged_once) << NOTIMPLEMENTED_MSG;\ 955 logged_once = true;\ 956} while(0);\ 957EAT_STREAM_PARAMETERS 958#endif 959 960#endif // BASE_LOGGING_H_ 961