logging.h revision ddb351dbec246cf1fab5ec20d2d5520909041de1
1// Copyright (c) 2011 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#pragma once 8 9#include <string> 10#include <cstring> 11#include <sstream> 12 13#include "base/base_api.h" 14#include "base/basictypes.h" 15#include "build/build_config.h" 16 17// 18// Optional message capabilities 19// ----------------------------- 20// Assertion failed messages and fatal errors are displayed in a dialog box 21// before the application exits. However, running this UI creates a message 22// loop, which causes application messages to be processed and potentially 23// dispatched to existing application windows. Since the application is in a 24// bad state when this assertion dialog is displayed, these messages may not 25// get processed and hang the dialog, or the application might go crazy. 26// 27// Therefore, it can be beneficial to display the error dialog in a separate 28// process from the main application. When the logging system needs to display 29// a fatal error dialog box, it will look for a program called 30// "DebugMessage.exe" in the same directory as the application executable. It 31// will run this application with the message as the command line, and will 32// not include the name of the application as is traditional for easier 33// parsing. 34// 35// The code for DebugMessage.exe is only one line. In WinMain, do: 36// MessageBox(NULL, GetCommandLineW(), L"Fatal Error", 0); 37// 38// If DebugMessage.exe is not found, the logging code will use a normal 39// MessageBox, potentially causing the problems discussed above. 40 41 42// Instructions 43// ------------ 44// 45// Make a bunch of macros for logging. The way to log things is to stream 46// things to LOG(<a particular severity level>). E.g., 47// 48// LOG(INFO) << "Found " << num_cookies << " cookies"; 49// 50// You can also do conditional logging: 51// 52// LOG_IF(INFO, num_cookies > 10) << "Got lots of cookies"; 53// 54// The above will cause log messages to be output on the 1st, 11th, 21st, ... 55// times it is executed. Note that the special COUNTER value is used to 56// identify which repetition is happening. 57// 58// The CHECK(condition) macro is active in both debug and release builds and 59// effectively performs a LOG(FATAL) which terminates the process and 60// generates a crashdump unless a debugger is attached. 61// 62// There are also "debug mode" logging macros like the ones above: 63// 64// DLOG(INFO) << "Found cookies"; 65// 66// DLOG_IF(INFO, num_cookies > 10) << "Got lots of cookies"; 67// 68// All "debug mode" logging is compiled away to nothing for non-debug mode 69// compiles. LOG_IF and development flags also work well together 70// because the code can be compiled away sometimes. 71// 72// We also have 73// 74// LOG_ASSERT(assertion); 75// DLOG_ASSERT(assertion); 76// 77// which is syntactic sugar for {,D}LOG_IF(FATAL, assert fails) << assertion; 78// 79// There are "verbose level" logging macros. They look like 80// 81// VLOG(1) << "I'm printed when you run the program with --v=1 or more"; 82// VLOG(2) << "I'm printed when you run the program with --v=2 or more"; 83// 84// These always log at the INFO log level (when they log at all). 85// The verbose logging can also be turned on module-by-module. For instance, 86// --vmodule=profile=2,icon_loader=1,browser_*=3,*/chromeos/*=4 --v=0 87// will cause: 88// a. VLOG(2) and lower messages to be printed from profile.{h,cc} 89// b. VLOG(1) and lower messages to be printed from icon_loader.{h,cc} 90// c. VLOG(3) and lower messages to be printed from files prefixed with 91// "browser" 92// d. VLOG(4) and lower messages to be printed from files under a 93// "chromeos" directory. 94// e. VLOG(0) and lower messages to be printed from elsewhere 95// 96// The wildcarding functionality shown by (c) supports both '*' (match 97// 0 or more characters) and '?' (match any single character) 98// wildcards. Any pattern containing a forward or backward slash will 99// be tested against the whole pathname and not just the module. 100// E.g., "*/foo/bar/*=2" would change the logging level for all code 101// in source files under a "foo/bar" directory. 102// 103// There's also VLOG_IS_ON(n) "verbose level" condition macro. To be used as 104// 105// if (VLOG_IS_ON(2)) { 106// // do some logging preparation and logging 107// // that can't be accomplished with just VLOG(2) << ...; 108// } 109// 110// There is also a VLOG_IF "verbose level" condition macro for sample 111// cases, when some extra computation and preparation for logs is not 112// needed. 113// 114// VLOG_IF(1, (size > 1024)) 115// << "I'm printed when size is more than 1024 and when you run the " 116// "program with --v=1 or more"; 117// 118// We also override the standard 'assert' to use 'DLOG_ASSERT'. 119// 120// Lastly, there is: 121// 122// PLOG(ERROR) << "Couldn't do foo"; 123// DPLOG(ERROR) << "Couldn't do foo"; 124// PLOG_IF(ERROR, cond) << "Couldn't do foo"; 125// DPLOG_IF(ERROR, cond) << "Couldn't do foo"; 126// PCHECK(condition) << "Couldn't do foo"; 127// DPCHECK(condition) << "Couldn't do foo"; 128// 129// which append the last system error to the message in string form (taken from 130// GetLastError() on Windows and errno on POSIX). 131// 132// The supported severity levels for macros that allow you to specify one 133// are (in increasing order of severity) INFO, WARNING, ERROR, ERROR_REPORT, 134// and FATAL. 135// 136// Very important: logging a message at the FATAL severity level causes 137// the program to terminate (after the message is logged). 138// 139// Note the special severity of ERROR_REPORT only available/relevant in normal 140// mode, which displays error dialog without terminating the program. There is 141// no error dialog for severity ERROR or below in normal mode. 142// 143// There is also the special severity of DFATAL, which logs FATAL in 144// debug mode, ERROR in normal mode. 145 146namespace logging { 147 148// Where to record logging output? A flat file and/or system debug log via 149// OutputDebugString. Defaults on Windows to LOG_ONLY_TO_FILE, and on 150// POSIX to LOG_ONLY_TO_SYSTEM_DEBUG_LOG (aka stderr). 151enum LoggingDestination { LOG_NONE, 152 LOG_ONLY_TO_FILE, 153 LOG_ONLY_TO_SYSTEM_DEBUG_LOG, 154 LOG_TO_BOTH_FILE_AND_SYSTEM_DEBUG_LOG }; 155 156// Indicates that the log file should be locked when being written to. 157// Often, there is no locking, which is fine for a single threaded program. 158// If logging is being done from multiple threads or there can be more than 159// one process doing the logging, the file should be locked during writes to 160// make each log outut atomic. Other writers will block. 161// 162// All processes writing to the log file must have their locking set for it to 163// work properly. Defaults to DONT_LOCK_LOG_FILE. 164enum LogLockingState { LOCK_LOG_FILE, DONT_LOCK_LOG_FILE }; 165 166// On startup, should we delete or append to an existing log file (if any)? 167// Defaults to APPEND_TO_OLD_LOG_FILE. 168enum OldFileDeletionState { DELETE_OLD_LOG_FILE, APPEND_TO_OLD_LOG_FILE }; 169 170enum DcheckState { 171 DISABLE_DCHECK_FOR_NON_OFFICIAL_RELEASE_BUILDS, 172 ENABLE_DCHECK_FOR_NON_OFFICIAL_RELEASE_BUILDS 173}; 174 175// TODO(avi): do we want to do a unification of character types here? 176#if defined(OS_WIN) 177typedef wchar_t PathChar; 178#else 179typedef char PathChar; 180#endif 181 182// Define different names for the BaseInitLoggingImpl() function depending on 183// whether NDEBUG is defined or not so that we'll fail to link if someone tries 184// to compile logging.cc with NDEBUG but includes logging.h without defining it, 185// or vice versa. 186#if NDEBUG 187#define BaseInitLoggingImpl BaseInitLoggingImpl_built_with_NDEBUG 188#else 189#define BaseInitLoggingImpl BaseInitLoggingImpl_built_without_NDEBUG 190#endif 191 192// Implementation of the InitLogging() method declared below. We use a 193// more-specific name so we can #define it above without affecting other code 194// that has named stuff "InitLogging". 195BASE_API bool BaseInitLoggingImpl(const PathChar* log_file, 196 LoggingDestination logging_dest, 197 LogLockingState lock_log, 198 OldFileDeletionState delete_old, 199 DcheckState dcheck_state); 200 201// Sets the log file name and other global logging state. Calling this function 202// is recommended, and is normally done at the beginning of application init. 203// If you don't call it, all the flags will be initialized to their default 204// values, and there is a race condition that may leak a critical section 205// object if two threads try to do the first log at the same time. 206// See the definition of the enums above for descriptions and default values. 207// 208// The default log file is initialized to "debug.log" in the application 209// directory. You probably don't want this, especially since the program 210// directory may not be writable on an enduser's system. 211inline bool InitLogging(const PathChar* log_file, 212 LoggingDestination logging_dest, 213 LogLockingState lock_log, 214 OldFileDeletionState delete_old, 215 DcheckState dcheck_state) { 216 return BaseInitLoggingImpl(log_file, logging_dest, lock_log, 217 delete_old, dcheck_state); 218} 219 220// Sets the log level. Anything at or above this level will be written to the 221// log file/displayed to the user (if applicable). Anything below this level 222// will be silently ignored. The log level defaults to 0 (everything is logged 223// up to level INFO) if this function is not called. 224// Note that log messages for VLOG(x) are logged at level -x, so setting 225// the min log level to negative values enables verbose logging. 226BASE_API void SetMinLogLevel(int level); 227 228// Gets the current log level. 229BASE_API int GetMinLogLevel(); 230 231// Gets the VLOG default verbosity level. 232BASE_API int GetVlogVerbosity(); 233 234// Gets the current vlog level for the given file (usually taken from 235// __FILE__). 236 237// Note that |N| is the size *with* the null terminator. 238BASE_API int GetVlogLevelHelper(const char* file_start, size_t N); 239 240template <size_t N> 241int GetVlogLevel(const char (&file)[N]) { 242 return GetVlogLevelHelper(file, N); 243} 244 245// Sets the common items you want to be prepended to each log message. 246// process and thread IDs default to off, the timestamp defaults to on. 247// If this function is not called, logging defaults to writing the timestamp 248// only. 249BASE_API void SetLogItems(bool enable_process_id, bool enable_thread_id, 250 bool enable_timestamp, bool enable_tickcount); 251 252// Sets whether or not you'd like to see fatal debug messages popped up in 253// a dialog box or not. 254// Dialogs are not shown by default. 255BASE_API void SetShowErrorDialogs(bool enable_dialogs); 256 257// Sets the Log Assert Handler that will be used to notify of check failures. 258// The default handler shows a dialog box and then terminate the process, 259// however clients can use this function to override with their own handling 260// (e.g. a silent one for Unit Tests) 261typedef void (*LogAssertHandlerFunction)(const std::string& str); 262BASE_API void SetLogAssertHandler(LogAssertHandlerFunction handler); 263 264// Sets the Log Report Handler that will be used to notify of check failures 265// in non-debug mode. The default handler shows a dialog box and continues 266// the execution, however clients can use this function to override with their 267// own handling. 268typedef void (*LogReportHandlerFunction)(const std::string& str); 269BASE_API void SetLogReportHandler(LogReportHandlerFunction handler); 270 271// Sets the Log Message Handler that gets passed every log message before 272// it's sent to other log destinations (if any). 273// Returns true to signal that it handled the message and the message 274// should not be sent to other log destinations. 275typedef bool (*LogMessageHandlerFunction)(int severity, 276 const char* file, int line, size_t message_start, const std::string& str); 277BASE_API void SetLogMessageHandler(LogMessageHandlerFunction handler); 278BASE_API LogMessageHandlerFunction GetLogMessageHandler(); 279 280typedef int LogSeverity; 281const LogSeverity LOG_VERBOSE = -1; // This is level 1 verbosity 282// Note: the log severities are used to index into the array of names, 283// see log_severity_names. 284const LogSeverity LOG_INFO = 0; 285const LogSeverity LOG_WARNING = 1; 286const LogSeverity LOG_ERROR = 2; 287const LogSeverity LOG_ERROR_REPORT = 3; 288const LogSeverity LOG_FATAL = 4; 289const LogSeverity LOG_NUM_SEVERITIES = 5; 290 291// LOG_DFATAL is LOG_FATAL in debug mode, ERROR in normal mode 292#ifdef NDEBUG 293const LogSeverity LOG_DFATAL = LOG_ERROR; 294#else 295const LogSeverity LOG_DFATAL = LOG_FATAL; 296#endif 297 298// A few definitions of macros that don't generate much code. These are used 299// by LOG() and LOG_IF, etc. Since these are used all over our code, it's 300// better to have compact code for these operations. 301#define COMPACT_GOOGLE_LOG_EX_INFO(ClassName, ...) \ 302 logging::ClassName(__FILE__, __LINE__, logging::LOG_INFO , ##__VA_ARGS__) 303#define COMPACT_GOOGLE_LOG_EX_WARNING(ClassName, ...) \ 304 logging::ClassName(__FILE__, __LINE__, logging::LOG_WARNING , ##__VA_ARGS__) 305#define COMPACT_GOOGLE_LOG_EX_ERROR(ClassName, ...) \ 306 logging::ClassName(__FILE__, __LINE__, logging::LOG_ERROR , ##__VA_ARGS__) 307#define COMPACT_GOOGLE_LOG_EX_ERROR_REPORT(ClassName, ...) \ 308 logging::ClassName(__FILE__, __LINE__, \ 309 logging::LOG_ERROR_REPORT , ##__VA_ARGS__) 310#define COMPACT_GOOGLE_LOG_EX_FATAL(ClassName, ...) \ 311 logging::ClassName(__FILE__, __LINE__, logging::LOG_FATAL , ##__VA_ARGS__) 312#define COMPACT_GOOGLE_LOG_EX_DFATAL(ClassName, ...) \ 313 logging::ClassName(__FILE__, __LINE__, logging::LOG_DFATAL , ##__VA_ARGS__) 314 315#define COMPACT_GOOGLE_LOG_INFO \ 316 COMPACT_GOOGLE_LOG_EX_INFO(LogMessage) 317#define COMPACT_GOOGLE_LOG_WARNING \ 318 COMPACT_GOOGLE_LOG_EX_WARNING(LogMessage) 319#define COMPACT_GOOGLE_LOG_ERROR \ 320 COMPACT_GOOGLE_LOG_EX_ERROR(LogMessage) 321#define COMPACT_GOOGLE_LOG_ERROR_REPORT \ 322 COMPACT_GOOGLE_LOG_EX_ERROR_REPORT(LogMessage) 323#define COMPACT_GOOGLE_LOG_FATAL \ 324 COMPACT_GOOGLE_LOG_EX_FATAL(LogMessage) 325#define COMPACT_GOOGLE_LOG_DFATAL \ 326 COMPACT_GOOGLE_LOG_EX_DFATAL(LogMessage) 327 328// wingdi.h defines ERROR to be 0. When we call LOG(ERROR), it gets 329// substituted with 0, and it expands to COMPACT_GOOGLE_LOG_0. To allow us 330// to keep using this syntax, we define this macro to do the same thing 331// as COMPACT_GOOGLE_LOG_ERROR, and also define ERROR the same way that 332// the Windows SDK does for consistency. 333#define ERROR 0 334#define COMPACT_GOOGLE_LOG_EX_0(ClassName, ...) \ 335 COMPACT_GOOGLE_LOG_EX_ERROR(ClassName , ##__VA_ARGS__) 336#define COMPACT_GOOGLE_LOG_0 COMPACT_GOOGLE_LOG_ERROR 337// Needed for LOG_IS_ON(ERROR). 338const LogSeverity LOG_0 = LOG_ERROR; 339 340// As special cases, we can assume that LOG_IS_ON(ERROR_REPORT) and 341// LOG_IS_ON(FATAL) always hold. Also, LOG_IS_ON(DFATAL) always holds 342// in debug mode. In particular, CHECK()s will always fire if they 343// fail. 344#define LOG_IS_ON(severity) \ 345 ((::logging::LOG_ ## severity) >= ::logging::GetMinLogLevel()) 346 347// We can't do any caching tricks with VLOG_IS_ON() like the 348// google-glog version since it requires GCC extensions. This means 349// that using the v-logging functions in conjunction with --vmodule 350// may be slow. 351#define VLOG_IS_ON(verboselevel) \ 352 ((verboselevel) <= ::logging::GetVlogLevel(__FILE__)) 353 354// Helper macro which avoids evaluating the arguments to a stream if 355// the condition doesn't hold. 356#define LAZY_STREAM(stream, condition) \ 357 !(condition) ? (void) 0 : ::logging::LogMessageVoidify() & (stream) 358 359// We use the preprocessor's merging operator, "##", so that, e.g., 360// LOG(INFO) becomes the token COMPACT_GOOGLE_LOG_INFO. There's some funny 361// subtle difference between ostream member streaming functions (e.g., 362// ostream::operator<<(int) and ostream non-member streaming functions 363// (e.g., ::operator<<(ostream&, string&): it turns out that it's 364// impossible to stream something like a string directly to an unnamed 365// ostream. We employ a neat hack by calling the stream() member 366// function of LogMessage which seems to avoid the problem. 367#define LOG_STREAM(severity) COMPACT_GOOGLE_LOG_ ## severity.stream() 368 369#define LOG(severity) LAZY_STREAM(LOG_STREAM(severity), LOG_IS_ON(severity)) 370#define LOG_IF(severity, condition) \ 371 LAZY_STREAM(LOG_STREAM(severity), LOG_IS_ON(severity) && (condition)) 372 373#define SYSLOG(severity) LOG(severity) 374#define SYSLOG_IF(severity, condition) LOG_IF(severity, condition) 375 376// The VLOG macros log with negative verbosities. 377#define VLOG_STREAM(verbose_level) \ 378 logging::LogMessage(__FILE__, __LINE__, -verbose_level).stream() 379 380#define VLOG(verbose_level) \ 381 LAZY_STREAM(VLOG_STREAM(verbose_level), VLOG_IS_ON(verbose_level)) 382 383#define VLOG_IF(verbose_level, condition) \ 384 LAZY_STREAM(VLOG_STREAM(verbose_level), \ 385 VLOG_IS_ON(verbose_level) && (condition)) 386 387#if defined (OS_WIN) 388#define VPLOG_STREAM(verbose_level) \ 389 logging::Win32ErrorLogMessage(__FILE__, __LINE__, -verbose_level, \ 390 ::logging::GetLastSystemErrorCode()).stream() 391#elif defined(OS_POSIX) 392#define VPLOG_STREAM(verbose_level) \ 393 logging::ErrnoLogMessage(__FILE__, __LINE__, -verbose_level, \ 394 ::logging::GetLastSystemErrorCode()).stream() 395#endif 396 397#define VPLOG(verbose_level) \ 398 LAZY_STREAM(VPLOG_STREAM(verbose_level), VLOG_IS_ON(verbose_level)) 399 400#define VPLOG_IF(verbose_level, condition) \ 401 LAZY_STREAM(VPLOG_STREAM(verbose_level), \ 402 VLOG_IS_ON(verbose_level) && (condition)) 403 404// TODO(akalin): Add more VLOG variants, e.g. VPLOG. 405 406#define LOG_ASSERT(condition) \ 407 LOG_IF(FATAL, !(condition)) << "Assert failed: " #condition ". " 408#define SYSLOG_ASSERT(condition) \ 409 SYSLOG_IF(FATAL, !(condition)) << "Assert failed: " #condition ". " 410 411#if defined(OS_WIN) 412#define LOG_GETLASTERROR_STREAM(severity) \ 413 COMPACT_GOOGLE_LOG_EX_ ## severity(Win32ErrorLogMessage, \ 414 ::logging::GetLastSystemErrorCode()).stream() 415#define LOG_GETLASTERROR(severity) \ 416 LAZY_STREAM(LOG_GETLASTERROR_STREAM(severity), LOG_IS_ON(severity)) 417#define LOG_GETLASTERROR_MODULE_STREAM(severity, module) \ 418 COMPACT_GOOGLE_LOG_EX_ ## severity(Win32ErrorLogMessage, \ 419 ::logging::GetLastSystemErrorCode(), module).stream() 420#define LOG_GETLASTERROR_MODULE(severity, module) \ 421 LAZY_STREAM(LOG_GETLASTERROR_STREAM(severity, module), \ 422 LOG_IS_ON(severity)) 423// PLOG_STREAM is used by PLOG, which is the usual error logging macro 424// for each platform. 425#define PLOG_STREAM(severity) LOG_GETLASTERROR_STREAM(severity) 426#elif defined(OS_POSIX) 427#define LOG_ERRNO_STREAM(severity) \ 428 COMPACT_GOOGLE_LOG_EX_ ## severity(ErrnoLogMessage, \ 429 ::logging::GetLastSystemErrorCode()).stream() 430#define LOG_ERRNO(severity) \ 431 LAZY_STREAM(LOG_ERRNO_STREAM(severity), LOG_IS_ON(severity)) 432// PLOG_STREAM is used by PLOG, which is the usual error logging macro 433// for each platform. 434#define PLOG_STREAM(severity) LOG_ERRNO_STREAM(severity) 435// TODO(tschmelcher): Should we add OSStatus logging for Mac? 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// CHECK dies with a fatal error if condition is not true. It is *not* 445// controlled by NDEBUG, so the check will be executed regardless of 446// compilation mode. 447// 448// We make sure CHECK et al. always evaluates their arguments, as 449// doing CHECK(FunctionWithSideEffect()) is a common idiom. 450#define CHECK(condition) \ 451 LAZY_STREAM(LOG_STREAM(FATAL), !(condition)) \ 452 << "Check failed: " #condition ". " 453 454#define PCHECK(condition) \ 455 LAZY_STREAM(PLOG_STREAM(FATAL), !(condition)) \ 456 << "Check failed: " #condition ". " 457 458// Build the error message string. This is separate from the "Impl" 459// function template because it is not performance critical and so can 460// be out of line, while the "Impl" code should be inline. Caller 461// takes ownership of the returned string. 462template<class t1, class t2> 463std::string* MakeCheckOpString(const t1& v1, const t2& v2, const char* names) { 464 std::ostringstream ss; 465 ss << names << " (" << v1 << " vs. " << v2 << ")"; 466 std::string* msg = new std::string(ss.str()); 467 return msg; 468} 469 470// MSVC doesn't like complex extern templates and DLLs. 471#if !defined(COMPILER_MSVC) 472// Commonly used instantiations of MakeCheckOpString<>. Explicitly instantiated 473// in logging.cc. 474extern template std::string* MakeCheckOpString<int, int>( 475 const int&, const int&, const char* names); 476extern template std::string* MakeCheckOpString<unsigned long, unsigned long>( 477 const unsigned long&, const unsigned long&, const char* names); 478extern template std::string* MakeCheckOpString<unsigned long, unsigned int>( 479 const unsigned long&, const unsigned int&, const char* names); 480extern template std::string* MakeCheckOpString<unsigned int, unsigned long>( 481 const unsigned int&, const unsigned long&, const char* names); 482extern template std::string* MakeCheckOpString<std::string, std::string>( 483 const std::string&, const std::string&, const char* name); 484#endif 485 486// Helper macro for binary operators. 487// Don't use this macro directly in your code, use CHECK_EQ et al below. 488// 489// TODO(akalin): Rewrite this so that constructs like if (...) 490// CHECK_EQ(...) else { ... } work properly. 491#define CHECK_OP(name, op, val1, val2) \ 492 if (std::string* _result = \ 493 logging::Check##name##Impl((val1), (val2), \ 494 #val1 " " #op " " #val2)) \ 495 logging::LogMessage(__FILE__, __LINE__, _result).stream() 496 497// Helper functions for CHECK_OP macro. 498// The (int, int) specialization works around the issue that the compiler 499// will not instantiate the template version of the function on values of 500// unnamed enum type - see comment below. 501#define DEFINE_CHECK_OP_IMPL(name, op) \ 502 template <class t1, class t2> \ 503 inline std::string* Check##name##Impl(const t1& v1, const t2& v2, \ 504 const char* names) { \ 505 if (v1 op v2) return NULL; \ 506 else return MakeCheckOpString(v1, v2, names); \ 507 } \ 508 inline std::string* Check##name##Impl(int v1, int v2, const char* names) { \ 509 if (v1 op v2) return NULL; \ 510 else return MakeCheckOpString(v1, v2, names); \ 511 } 512DEFINE_CHECK_OP_IMPL(EQ, ==) 513DEFINE_CHECK_OP_IMPL(NE, !=) 514DEFINE_CHECK_OP_IMPL(LE, <=) 515DEFINE_CHECK_OP_IMPL(LT, < ) 516DEFINE_CHECK_OP_IMPL(GE, >=) 517DEFINE_CHECK_OP_IMPL(GT, > ) 518#undef DEFINE_CHECK_OP_IMPL 519 520#define CHECK_EQ(val1, val2) CHECK_OP(EQ, ==, val1, val2) 521#define CHECK_NE(val1, val2) CHECK_OP(NE, !=, val1, val2) 522#define CHECK_LE(val1, val2) CHECK_OP(LE, <=, val1, val2) 523#define CHECK_LT(val1, val2) CHECK_OP(LT, < , val1, val2) 524#define CHECK_GE(val1, val2) CHECK_OP(GE, >=, val1, val2) 525#define CHECK_GT(val1, val2) CHECK_OP(GT, > , val1, val2) 526 527// http://crbug.com/16512 is open for a real fix for this. For now, Windows 528// uses OFFICIAL_BUILD and other platforms use the branding flag when NDEBUG is 529// defined. 530#if ( defined(OS_WIN) && defined(OFFICIAL_BUILD)) || \ 531 (!defined(OS_WIN) && defined(NDEBUG) && defined(GOOGLE_CHROME_BUILD)) 532// Used by unit tests. 533#define LOGGING_IS_OFFICIAL_BUILD 534 535// In order to have optimized code for official builds, remove DLOGs and 536// DCHECKs. 537#define ENABLE_DLOG 0 538#define ENABLE_DCHECK 0 539 540#elif defined(NDEBUG) 541// Otherwise, if we're a release build, remove DLOGs but not DCHECKs 542// (since those can still be turned on via a command-line flag). 543#define ENABLE_DLOG 0 544#define ENABLE_DCHECK 1 545 546#else 547// Otherwise, we're a debug build so enable DLOGs and DCHECKs. 548#define ENABLE_DLOG 1 549#define ENABLE_DCHECK 1 550#endif 551 552// Definitions for DLOG et al. 553 554#if ENABLE_DLOG 555 556#define DLOG_IS_ON(severity) LOG_IS_ON(severity) 557#define DLOG_IF(severity, condition) LOG_IF(severity, condition) 558#define DLOG_ASSERT(condition) LOG_ASSERT(condition) 559#define DPLOG_IF(severity, condition) PLOG_IF(severity, condition) 560#define DVLOG_IF(verboselevel, condition) VLOG_IF(verboselevel, condition) 561#define DVPLOG_IF(verboselevel, condition) VPLOG_IF(verboselevel, condition) 562 563#else // ENABLE_DLOG 564 565// If ENABLE_DLOG is off, we want to avoid emitting any references to 566// |condition| (which may reference a variable defined only if NDEBUG 567// is not defined). Contrast this with DCHECK et al., which has 568// different behavior. 569 570#define DLOG_EAT_STREAM_PARAMETERS \ 571 true ? (void) 0 : ::logging::LogMessageVoidify() & LOG_STREAM(FATAL) 572 573#define DLOG_IS_ON(severity) false 574#define DLOG_IF(severity, condition) DLOG_EAT_STREAM_PARAMETERS 575#define DLOG_ASSERT(condition) DLOG_EAT_STREAM_PARAMETERS 576#define DPLOG_IF(severity, condition) DLOG_EAT_STREAM_PARAMETERS 577#define DVLOG_IF(verboselevel, condition) DLOG_EAT_STREAM_PARAMETERS 578#define DVPLOG_IF(verboselevel, condition) DLOG_EAT_STREAM_PARAMETERS 579 580#endif // ENABLE_DLOG 581 582// DEBUG_MODE is for uses like 583// if (DEBUG_MODE) foo.CheckThatFoo(); 584// instead of 585// #ifndef NDEBUG 586// foo.CheckThatFoo(); 587// #endif 588// 589// We tie its state to ENABLE_DLOG. 590enum { DEBUG_MODE = ENABLE_DLOG }; 591 592#undef ENABLE_DLOG 593 594#define DLOG(severity) \ 595 LAZY_STREAM(LOG_STREAM(severity), DLOG_IS_ON(severity)) 596 597#if defined(OS_WIN) 598#define DLOG_GETLASTERROR(severity) \ 599 LAZY_STREAM(LOG_GETLASTERROR_STREAM(severity), DLOG_IS_ON(severity)) 600#define DLOG_GETLASTERROR_MODULE(severity, module) \ 601 LAZY_STREAM(LOG_GETLASTERROR_STREAM(severity, module), \ 602 DLOG_IS_ON(severity)) 603#elif defined(OS_POSIX) 604#define DLOG_ERRNO(severity) \ 605 LAZY_STREAM(LOG_ERRNO_STREAM(severity), DLOG_IS_ON(severity)) 606#endif 607 608#define DPLOG(severity) \ 609 LAZY_STREAM(PLOG_STREAM(severity), DLOG_IS_ON(severity)) 610 611#define DVLOG(verboselevel) DLOG_IF(INFO, VLOG_IS_ON(verboselevel)) 612 613#define DVPLOG(verboselevel) DVPLOG_IF(verboselevel, VLOG_IS_ON(verboselevel)) 614 615// Definitions for DCHECK et al. 616 617#if ENABLE_DCHECK 618 619#if defined(NDEBUG) 620 621#define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \ 622 COMPACT_GOOGLE_LOG_EX_ERROR_REPORT(ClassName , ##__VA_ARGS__) 623#define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_ERROR_REPORT 624const LogSeverity LOG_DCHECK = LOG_ERROR_REPORT; 625extern DcheckState g_dcheck_state; 626#define DCHECK_IS_ON() \ 627 ((::logging::g_dcheck_state == \ 628 ::logging::ENABLE_DCHECK_FOR_NON_OFFICIAL_RELEASE_BUILDS) && \ 629 LOG_IS_ON(DCHECK)) 630 631#else // defined(NDEBUG) 632 633// On a regular debug build, we want to have DCHECKs enabled. 634#define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \ 635 COMPACT_GOOGLE_LOG_EX_FATAL(ClassName , ##__VA_ARGS__) 636#define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_FATAL 637const LogSeverity LOG_DCHECK = LOG_FATAL; 638#define DCHECK_IS_ON() true 639 640#endif // defined(NDEBUG) 641 642#else // ENABLE_DCHECK 643 644// These are just dummy values since DCHECK_IS_ON() is always false in 645// this case. 646#define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \ 647 COMPACT_GOOGLE_LOG_EX_INFO(ClassName , ##__VA_ARGS__) 648#define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_INFO 649const LogSeverity LOG_DCHECK = LOG_INFO; 650#define DCHECK_IS_ON() false 651 652#endif // ENABLE_DCHECK 653#undef ENABLE_DCHECK 654 655// DCHECK et al. make sure to reference |condition| regardless of 656// whether DCHECKs are enabled; this is so that we don't get unused 657// variable warnings if the only use of a variable is in a DCHECK. 658// This behavior is different from DLOG_IF et al. 659 660#define DCHECK(condition) \ 661 LAZY_STREAM(LOG_STREAM(DCHECK), DCHECK_IS_ON() && !(condition)) \ 662 << "Check failed: " #condition ". " 663 664#define DPCHECK(condition) \ 665 LAZY_STREAM(PLOG_STREAM(DCHECK), DCHECK_IS_ON() && !(condition)) \ 666 << "Check failed: " #condition ". " 667 668// Helper macro for binary operators. 669// Don't use this macro directly in your code, use DCHECK_EQ et al below. 670#define DCHECK_OP(name, op, val1, val2) \ 671 if (DCHECK_IS_ON()) \ 672 if (std::string* _result = \ 673 logging::Check##name##Impl((val1), (val2), \ 674 #val1 " " #op " " #val2)) \ 675 logging::LogMessage( \ 676 __FILE__, __LINE__, ::logging::LOG_DCHECK, \ 677 _result).stream() 678 679// Equality/Inequality checks - compare two values, and log a 680// LOG_DCHECK message including the two values when the result is not 681// as expected. The values must have operator<<(ostream, ...) 682// defined. 683// 684// You may append to the error message like so: 685// DCHECK_NE(1, 2) << ": The world must be ending!"; 686// 687// We are very careful to ensure that each argument is evaluated exactly 688// once, and that anything which is legal to pass as a function argument is 689// legal here. In particular, the arguments may be temporary expressions 690// which will end up being destroyed at the end of the apparent statement, 691// for example: 692// DCHECK_EQ(string("abc")[1], 'b'); 693// 694// WARNING: These may not compile correctly if one of the arguments is a pointer 695// and the other is NULL. To work around this, simply static_cast NULL to the 696// type of the desired pointer. 697 698#define DCHECK_EQ(val1, val2) DCHECK_OP(EQ, ==, val1, val2) 699#define DCHECK_NE(val1, val2) DCHECK_OP(NE, !=, val1, val2) 700#define DCHECK_LE(val1, val2) DCHECK_OP(LE, <=, val1, val2) 701#define DCHECK_LT(val1, val2) DCHECK_OP(LT, < , val1, val2) 702#define DCHECK_GE(val1, val2) DCHECK_OP(GE, >=, val1, val2) 703#define DCHECK_GT(val1, val2) DCHECK_OP(GT, > , val1, val2) 704 705#define NOTREACHED() DCHECK(false) 706 707// Redefine the standard assert to use our nice log files 708#undef assert 709#define assert(x) DLOG_ASSERT(x) 710 711// This class more or less represents a particular log message. You 712// create an instance of LogMessage and then stream stuff to it. 713// When you finish streaming to it, ~LogMessage is called and the 714// full message gets streamed to the appropriate destination. 715// 716// You shouldn't actually use LogMessage's constructor to log things, 717// though. You should use the LOG() macro (and variants thereof) 718// above. 719class BASE_API LogMessage { 720 public: 721 LogMessage(const char* file, int line, LogSeverity severity, int ctr); 722 723 // Two special constructors that generate reduced amounts of code at 724 // LOG call sites for common cases. 725 // 726 // Used for LOG(INFO): Implied are: 727 // severity = LOG_INFO, ctr = 0 728 // 729 // Using this constructor instead of the more complex constructor above 730 // saves a couple of bytes per call site. 731 LogMessage(const char* file, int line); 732 733 // Used for LOG(severity) where severity != INFO. Implied 734 // are: ctr = 0 735 // 736 // Using this constructor instead of the more complex constructor above 737 // saves a couple of bytes per call site. 738 LogMessage(const char* file, int line, LogSeverity severity); 739 740 // A special constructor used for check failures. Takes ownership 741 // of the given string. 742 // Implied severity = LOG_FATAL 743 LogMessage(const char* file, int line, std::string* result); 744 745 // A special constructor used for check failures, with the option to 746 // specify severity. Takes ownership of the given string. 747 LogMessage(const char* file, int line, LogSeverity severity, 748 std::string* result); 749 750 ~LogMessage(); 751 752 std::ostream& stream() { return stream_; } 753 754 private: 755 void Init(const char* file, int line); 756 757 LogSeverity severity_; 758 std::ostringstream stream_; 759 size_t message_start_; // Offset of the start of the message (past prefix 760 // info). 761 // The file and line information passed in to the constructor. 762 const char* file_; 763 const int line_; 764 765#if defined(OS_WIN) 766 // Stores the current value of GetLastError in the constructor and restores 767 // it in the destructor by calling SetLastError. 768 // This is useful since the LogMessage class uses a lot of Win32 calls 769 // that will lose the value of GLE and the code that called the log function 770 // will have lost the thread error value when the log call returns. 771 class SaveLastError { 772 public: 773 SaveLastError(); 774 ~SaveLastError(); 775 776 unsigned long get_error() const { return last_error_; } 777 778 protected: 779 unsigned long last_error_; 780 }; 781 782 SaveLastError last_error_; 783#endif 784 785 DISALLOW_COPY_AND_ASSIGN(LogMessage); 786}; 787 788// A non-macro interface to the log facility; (useful 789// when the logging level is not a compile-time constant). 790inline void LogAtLevel(int const log_level, std::string const &msg) { 791 LogMessage(__FILE__, __LINE__, log_level).stream() << msg; 792} 793 794// This class is used to explicitly ignore values in the conditional 795// logging macros. This avoids compiler warnings like "value computed 796// is not used" and "statement has no effect". 797class BASE_API LogMessageVoidify { 798 public: 799 LogMessageVoidify() { } 800 // This has to be an operator with a precedence lower than << but 801 // higher than ?: 802 void operator&(std::ostream&) { } 803}; 804 805#if defined(OS_WIN) 806typedef unsigned long SystemErrorCode; 807#elif defined(OS_POSIX) 808typedef int SystemErrorCode; 809#endif 810 811// Alias for ::GetLastError() on Windows and errno on POSIX. Avoids having to 812// pull in windows.h just for GetLastError() and DWORD. 813BASE_API SystemErrorCode GetLastSystemErrorCode(); 814 815#if defined(OS_WIN) 816// Appends a formatted system message of the GetLastError() type. 817class BASE_API Win32ErrorLogMessage { 818 public: 819 Win32ErrorLogMessage(const char* file, 820 int line, 821 LogSeverity severity, 822 SystemErrorCode err, 823 const char* module); 824 825 Win32ErrorLogMessage(const char* file, 826 int line, 827 LogSeverity severity, 828 SystemErrorCode err); 829 830 // Appends the error message before destructing the encapsulated class. 831 ~Win32ErrorLogMessage(); 832 833 std::ostream& stream() { return log_message_.stream(); } 834 835 private: 836 SystemErrorCode err_; 837 // Optional name of the module defining the error. 838 const char* module_; 839 LogMessage log_message_; 840 841 DISALLOW_COPY_AND_ASSIGN(Win32ErrorLogMessage); 842}; 843#elif defined(OS_POSIX) 844// Appends a formatted system message of the errno type 845class ErrnoLogMessage { 846 public: 847 ErrnoLogMessage(const char* file, 848 int line, 849 LogSeverity severity, 850 SystemErrorCode err); 851 852 // Appends the error message before destructing the encapsulated class. 853 ~ErrnoLogMessage(); 854 855 std::ostream& stream() { return log_message_.stream(); } 856 857 private: 858 SystemErrorCode err_; 859 LogMessage log_message_; 860 861 DISALLOW_COPY_AND_ASSIGN(ErrnoLogMessage); 862}; 863#endif // OS_WIN 864 865// Closes the log file explicitly if open. 866// NOTE: Since the log file is opened as necessary by the action of logging 867// statements, there's no guarantee that it will stay closed 868// after this call. 869BASE_API void CloseLogFile(); 870 871// Async signal safe logging mechanism. 872BASE_API void RawLog(int level, const char* message); 873 874#define RAW_LOG(level, message) logging::RawLog(logging::LOG_ ## level, message) 875 876#define RAW_CHECK(condition) \ 877 do { \ 878 if (!(condition)) \ 879 logging::RawLog(logging::LOG_FATAL, "Check failed: " #condition "\n"); \ 880 } while (0) 881 882} // namespace logging 883 884// These functions are provided as a convenience for logging, which is where we 885// use streams (it is against Google style to use streams in other places). It 886// is designed to allow you to emit non-ASCII Unicode strings to the log file, 887// which is normally ASCII. It is relatively slow, so try not to use it for 888// common cases. Non-ASCII characters will be converted to UTF-8 by these 889// operators. 890BASE_API std::ostream& operator<<(std::ostream& out, const wchar_t* wstr); 891inline std::ostream& operator<<(std::ostream& out, const std::wstring& wstr) { 892 return out << wstr.c_str(); 893} 894 895// The NOTIMPLEMENTED() macro annotates codepaths which have 896// not been implemented yet. 897// 898// The implementation of this macro is controlled by NOTIMPLEMENTED_POLICY: 899// 0 -- Do nothing (stripped by compiler) 900// 1 -- Warn at compile time 901// 2 -- Fail at compile time 902// 3 -- Fail at runtime (DCHECK) 903// 4 -- [default] LOG(ERROR) at runtime 904// 5 -- LOG(ERROR) at runtime, only once per call-site 905 906#ifndef NOTIMPLEMENTED_POLICY 907// Select default policy: LOG(ERROR) 908#define NOTIMPLEMENTED_POLICY 4 909#endif 910 911#if defined(COMPILER_GCC) 912// On Linux, with GCC, we can use __PRETTY_FUNCTION__ to get the demangled name 913// of the current function in the NOTIMPLEMENTED message. 914#define NOTIMPLEMENTED_MSG "Not implemented reached in " << __PRETTY_FUNCTION__ 915#else 916#define NOTIMPLEMENTED_MSG "NOT IMPLEMENTED" 917#endif 918 919#if NOTIMPLEMENTED_POLICY == 0 920#define NOTIMPLEMENTED() ; 921#elif NOTIMPLEMENTED_POLICY == 1 922// TODO, figure out how to generate a warning 923#define NOTIMPLEMENTED() COMPILE_ASSERT(false, NOT_IMPLEMENTED) 924#elif NOTIMPLEMENTED_POLICY == 2 925#define NOTIMPLEMENTED() COMPILE_ASSERT(false, NOT_IMPLEMENTED) 926#elif NOTIMPLEMENTED_POLICY == 3 927#define NOTIMPLEMENTED() NOTREACHED() 928#elif NOTIMPLEMENTED_POLICY == 4 929#define NOTIMPLEMENTED() LOG(ERROR) << NOTIMPLEMENTED_MSG 930#elif NOTIMPLEMENTED_POLICY == 5 931#define NOTIMPLEMENTED() do {\ 932 static int count = 0;\ 933 LOG_IF(ERROR, 0 == count++) << NOTIMPLEMENTED_MSG;\ 934} while(0) 935#endif 936 937namespace base { 938 939class StringPiece; 940 941// Allows StringPiece to be logged. 942BASE_API std::ostream& operator<<(std::ostream& o, const StringPiece& piece); 943 944} // namespace base 945 946#endif // BASE_LOGGING_H_ 947