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 <stddef.h> 9 10#include <cassert> 11#include <cstring> 12#include <sstream> 13#include <string> 14#include <typeinfo> 15 16#include "base/base_export.h" 17#include "base/debug/debugger.h" 18#include "base/macros.h" 19#include "build/build_config.h" 20 21// 22// Optional message capabilities 23// ----------------------------- 24// Assertion failed messages and fatal errors are displayed in a dialog box 25// before the application exits. However, running this UI creates a message 26// loop, which causes application messages to be processed and potentially 27// dispatched to existing application windows. Since the application is in a 28// bad state when this assertion dialog is displayed, these messages may not 29// get processed and hang the dialog, or the application might go crazy. 30// 31// Therefore, it can be beneficial to display the error dialog in a separate 32// process from the main application. When the logging system needs to display 33// a fatal error dialog box, it will look for a program called 34// "DebugMessage.exe" in the same directory as the application executable. It 35// will run this application with the message as the command line, and will 36// not include the name of the application as is traditional for easier 37// parsing. 38// 39// The code for DebugMessage.exe is only one line. In WinMain, do: 40// MessageBox(NULL, GetCommandLineW(), L"Fatal Error", 0); 41// 42// If DebugMessage.exe is not found, the logging code will use a normal 43// MessageBox, potentially causing the problems discussed above. 44 45 46// Instructions 47// ------------ 48// 49// Make a bunch of macros for logging. The way to log things is to stream 50// things to LOG(<a particular severity level>). E.g., 51// 52// LOG(INFO) << "Found " << num_cookies << " cookies"; 53// 54// You can also do conditional logging: 55// 56// LOG_IF(INFO, num_cookies > 10) << "Got lots of cookies"; 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, and FATAL. 134// 135// Very important: logging a message at the FATAL severity level causes 136// the program to terminate (after the message is logged). 137// 138// There is the special severity of DFATAL, which logs FATAL in debug mode, 139// ERROR in normal mode. 140 141// Note that "The behavior of a C++ program is undefined if it adds declarations 142// or definitions to namespace std or to a namespace within namespace std unless 143// otherwise specified." --C++11[namespace.std] 144// 145// We've checked that this particular definition has the intended behavior on 146// our implementations, but it's prone to breaking in the future, and please 147// don't imitate this in your own definitions without checking with some 148// standard library experts. 149namespace std { 150// These functions are provided as a convenience for logging, which is where we 151// use streams (it is against Google style to use streams in other places). It 152// is designed to allow you to emit non-ASCII Unicode strings to the log file, 153// which is normally ASCII. It is relatively slow, so try not to use it for 154// common cases. Non-ASCII characters will be converted to UTF-8 by these 155// operators. 156BASE_EXPORT std::ostream& operator<<(std::ostream& out, const wchar_t* wstr); 157inline std::ostream& operator<<(std::ostream& out, const std::wstring& wstr) { 158 return out << wstr.c_str(); 159} 160 161template<typename T> 162typename std::enable_if<std::is_enum<T>::value, std::ostream&>::type operator<<( 163 std::ostream& out, T value) { 164 return out << static_cast<typename std::underlying_type<T>::type>(value); 165} 166 167} // namespace std 168 169namespace logging { 170 171// TODO(avi): do we want to do a unification of character types here? 172#if defined(OS_WIN) 173typedef wchar_t PathChar; 174#else 175typedef char PathChar; 176#endif 177 178// Where to record logging output? A flat file and/or system debug log 179// via OutputDebugString. 180enum LoggingDestination { 181 LOG_NONE = 0, 182 LOG_TO_FILE = 1 << 0, 183 LOG_TO_SYSTEM_DEBUG_LOG = 1 << 1, 184 185 LOG_TO_ALL = LOG_TO_FILE | LOG_TO_SYSTEM_DEBUG_LOG, 186 187 // On Windows, use a file next to the exe; on POSIX platforms, where 188 // it may not even be possible to locate the executable on disk, use 189 // stderr. 190#if defined(OS_WIN) 191 LOG_DEFAULT = LOG_TO_FILE, 192#elif defined(OS_POSIX) 193 LOG_DEFAULT = LOG_TO_SYSTEM_DEBUG_LOG, 194#endif 195}; 196 197// Indicates that the log file should be locked when being written to. 198// Unless there is only one single-threaded process that is logging to 199// the log file, the file should be locked during writes to make each 200// log output atomic. Other writers will block. 201// 202// All processes writing to the log file must have their locking set for it to 203// work properly. Defaults to LOCK_LOG_FILE. 204enum LogLockingState { LOCK_LOG_FILE, DONT_LOCK_LOG_FILE }; 205 206// On startup, should we delete or append to an existing log file (if any)? 207// Defaults to APPEND_TO_OLD_LOG_FILE. 208enum OldFileDeletionState { DELETE_OLD_LOG_FILE, APPEND_TO_OLD_LOG_FILE }; 209 210struct BASE_EXPORT LoggingSettings { 211 // The defaults values are: 212 // 213 // logging_dest: LOG_DEFAULT 214 // log_file: NULL 215 // lock_log: LOCK_LOG_FILE 216 // delete_old: APPEND_TO_OLD_LOG_FILE 217 LoggingSettings(); 218 219 LoggingDestination logging_dest; 220 221 // The three settings below have an effect only when LOG_TO_FILE is 222 // set in |logging_dest|. 223 const PathChar* log_file; 224 LogLockingState lock_log; 225 OldFileDeletionState delete_old; 226}; 227 228// Define different names for the BaseInitLoggingImpl() function depending on 229// whether NDEBUG is defined or not so that we'll fail to link if someone tries 230// to compile logging.cc with NDEBUG but includes logging.h without defining it, 231// or vice versa. 232#if NDEBUG 233#define BaseInitLoggingImpl BaseInitLoggingImpl_built_with_NDEBUG 234#else 235#define BaseInitLoggingImpl BaseInitLoggingImpl_built_without_NDEBUG 236#endif 237 238// Implementation of the InitLogging() method declared below. We use a 239// more-specific name so we can #define it above without affecting other code 240// that has named stuff "InitLogging". 241BASE_EXPORT bool BaseInitLoggingImpl(const LoggingSettings& settings); 242 243// Sets the log file name and other global logging state. Calling this function 244// is recommended, and is normally done at the beginning of application init. 245// If you don't call it, all the flags will be initialized to their default 246// values, and there is a race condition that may leak a critical section 247// object if two threads try to do the first log at the same time. 248// See the definition of the enums above for descriptions and default values. 249// 250// The default log file is initialized to "debug.log" in the application 251// directory. You probably don't want this, especially since the program 252// directory may not be writable on an enduser's system. 253// 254// This function may be called a second time to re-direct logging (e.g after 255// loging in to a user partition), however it should never be called more than 256// twice. 257inline bool InitLogging(const LoggingSettings& settings) { 258 return BaseInitLoggingImpl(settings); 259} 260 261// Sets the log level. Anything at or above this level will be written to the 262// log file/displayed to the user (if applicable). Anything below this level 263// will be silently ignored. The log level defaults to 0 (everything is logged 264// up to level INFO) if this function is not called. 265// Note that log messages for VLOG(x) are logged at level -x, so setting 266// the min log level to negative values enables verbose logging. 267BASE_EXPORT void SetMinLogLevel(int level); 268 269// Gets the current log level. 270BASE_EXPORT int GetMinLogLevel(); 271 272// Used by LOG_IS_ON to lazy-evaluate stream arguments. 273BASE_EXPORT bool ShouldCreateLogMessage(int severity); 274 275// Gets the VLOG default verbosity level. 276BASE_EXPORT int GetVlogVerbosity(); 277 278// Gets the current vlog level for the given file (usually taken from 279// __FILE__). 280 281// Note that |N| is the size *with* the null terminator. 282BASE_EXPORT int GetVlogLevelHelper(const char* file_start, size_t N); 283 284template <size_t N> 285int GetVlogLevel(const char (&file)[N]) { 286 return GetVlogLevelHelper(file, N); 287} 288 289// Sets the common items you want to be prepended to each log message. 290// process and thread IDs default to off, the timestamp defaults to on. 291// If this function is not called, logging defaults to writing the timestamp 292// only. 293BASE_EXPORT void SetLogItems(bool enable_process_id, bool enable_thread_id, 294 bool enable_timestamp, bool enable_tickcount); 295 296// Sets whether or not you'd like to see fatal debug messages popped up in 297// a dialog box or not. 298// Dialogs are not shown by default. 299BASE_EXPORT void SetShowErrorDialogs(bool enable_dialogs); 300 301// Sets the Log Assert Handler that will be used to notify of check failures. 302// The default handler shows a dialog box and then terminate the process, 303// however clients can use this function to override with their own handling 304// (e.g. a silent one for Unit Tests) 305typedef void (*LogAssertHandlerFunction)(const std::string& str); 306BASE_EXPORT void SetLogAssertHandler(LogAssertHandlerFunction handler); 307 308// Sets the Log Message Handler that gets passed every log message before 309// it's sent to other log destinations (if any). 310// Returns true to signal that it handled the message and the message 311// should not be sent to other log destinations. 312typedef bool (*LogMessageHandlerFunction)(int severity, 313 const char* file, int line, size_t message_start, const std::string& str); 314BASE_EXPORT void SetLogMessageHandler(LogMessageHandlerFunction handler); 315BASE_EXPORT LogMessageHandlerFunction GetLogMessageHandler(); 316 317typedef int LogSeverity; 318const LogSeverity LOG_VERBOSE = -1; // This is level 1 verbosity 319// Note: the log severities are used to index into the array of names, 320// see log_severity_names. 321const LogSeverity LOG_INFO = 0; 322const LogSeverity LOG_WARNING = 1; 323const LogSeverity LOG_ERROR = 2; 324const LogSeverity LOG_FATAL = 3; 325const LogSeverity LOG_NUM_SEVERITIES = 4; 326 327// LOG_DFATAL is LOG_FATAL in debug mode, ERROR in normal mode 328#ifdef NDEBUG 329const LogSeverity LOG_DFATAL = LOG_ERROR; 330#else 331const LogSeverity LOG_DFATAL = LOG_FATAL; 332#endif 333 334// A few definitions of macros that don't generate much code. These are used 335// by LOG() and LOG_IF, etc. Since these are used all over our code, it's 336// better to have compact code for these operations. 337#define COMPACT_GOOGLE_LOG_EX_INFO(ClassName, ...) \ 338 logging::ClassName(__FILE__, __LINE__, logging::LOG_INFO , ##__VA_ARGS__) 339#define COMPACT_GOOGLE_LOG_EX_WARNING(ClassName, ...) \ 340 logging::ClassName(__FILE__, __LINE__, logging::LOG_WARNING , ##__VA_ARGS__) 341#define COMPACT_GOOGLE_LOG_EX_ERROR(ClassName, ...) \ 342 logging::ClassName(__FILE__, __LINE__, logging::LOG_ERROR , ##__VA_ARGS__) 343#define COMPACT_GOOGLE_LOG_EX_FATAL(ClassName, ...) \ 344 logging::ClassName(__FILE__, __LINE__, logging::LOG_FATAL , ##__VA_ARGS__) 345#define COMPACT_GOOGLE_LOG_EX_DFATAL(ClassName, ...) \ 346 logging::ClassName(__FILE__, __LINE__, logging::LOG_DFATAL , ##__VA_ARGS__) 347 348#define COMPACT_GOOGLE_LOG_INFO \ 349 COMPACT_GOOGLE_LOG_EX_INFO(LogMessage) 350#define COMPACT_GOOGLE_LOG_WARNING \ 351 COMPACT_GOOGLE_LOG_EX_WARNING(LogMessage) 352#define COMPACT_GOOGLE_LOG_ERROR \ 353 COMPACT_GOOGLE_LOG_EX_ERROR(LogMessage) 354#define COMPACT_GOOGLE_LOG_FATAL \ 355 COMPACT_GOOGLE_LOG_EX_FATAL(LogMessage) 356#define COMPACT_GOOGLE_LOG_DFATAL \ 357 COMPACT_GOOGLE_LOG_EX_DFATAL(LogMessage) 358 359#if defined(OS_WIN) 360// wingdi.h defines ERROR to be 0. When we call LOG(ERROR), it gets 361// substituted with 0, and it expands to COMPACT_GOOGLE_LOG_0. To allow us 362// to keep using this syntax, we define this macro to do the same thing 363// as COMPACT_GOOGLE_LOG_ERROR, and also define ERROR the same way that 364// the Windows SDK does for consistency. 365#define ERROR 0 366#define COMPACT_GOOGLE_LOG_EX_0(ClassName, ...) \ 367 COMPACT_GOOGLE_LOG_EX_ERROR(ClassName , ##__VA_ARGS__) 368#define COMPACT_GOOGLE_LOG_0 COMPACT_GOOGLE_LOG_ERROR 369// Needed for LOG_IS_ON(ERROR). 370const LogSeverity LOG_0 = LOG_ERROR; 371#endif 372 373// As special cases, we can assume that LOG_IS_ON(FATAL) always holds. Also, 374// LOG_IS_ON(DFATAL) always holds in debug mode. In particular, CHECK()s will 375// always fire if they fail. 376#define LOG_IS_ON(severity) \ 377 (::logging::ShouldCreateLogMessage(::logging::LOG_##severity)) 378 379// We can't do any caching tricks with VLOG_IS_ON() like the 380// google-glog version since it requires GCC extensions. This means 381// that using the v-logging functions in conjunction with --vmodule 382// may be slow. 383#define VLOG_IS_ON(verboselevel) \ 384 ((verboselevel) <= ::logging::GetVlogLevel(__FILE__)) 385 386// Helper macro which avoids evaluating the arguments to a stream if 387// the condition doesn't hold. Condition is evaluated once and only once. 388#define LAZY_STREAM(stream, condition) \ 389 !(condition) ? (void) 0 : ::logging::LogMessageVoidify() & (stream) 390 391// We use the preprocessor's merging operator, "##", so that, e.g., 392// LOG(INFO) becomes the token COMPACT_GOOGLE_LOG_INFO. There's some funny 393// subtle difference between ostream member streaming functions (e.g., 394// ostream::operator<<(int) and ostream non-member streaming functions 395// (e.g., ::operator<<(ostream&, string&): it turns out that it's 396// impossible to stream something like a string directly to an unnamed 397// ostream. We employ a neat hack by calling the stream() member 398// function of LogMessage which seems to avoid the problem. 399#define LOG_STREAM(severity) COMPACT_GOOGLE_LOG_ ## severity.stream() 400 401#define LOG(severity) LAZY_STREAM(LOG_STREAM(severity), LOG_IS_ON(severity)) 402#define LOG_IF(severity, condition) \ 403 LAZY_STREAM(LOG_STREAM(severity), LOG_IS_ON(severity) && (condition)) 404 405#define SYSLOG(severity) LOG(severity) 406#define SYSLOG_IF(severity, condition) LOG_IF(severity, condition) 407 408// The VLOG macros log with negative verbosities. 409#define VLOG_STREAM(verbose_level) \ 410 logging::LogMessage(__FILE__, __LINE__, -verbose_level).stream() 411 412#define VLOG(verbose_level) \ 413 LAZY_STREAM(VLOG_STREAM(verbose_level), VLOG_IS_ON(verbose_level)) 414 415#define VLOG_IF(verbose_level, condition) \ 416 LAZY_STREAM(VLOG_STREAM(verbose_level), \ 417 VLOG_IS_ON(verbose_level) && (condition)) 418 419#if defined (OS_WIN) 420#define VPLOG_STREAM(verbose_level) \ 421 logging::Win32ErrorLogMessage(__FILE__, __LINE__, -verbose_level, \ 422 ::logging::GetLastSystemErrorCode()).stream() 423#elif defined(OS_POSIX) 424#define VPLOG_STREAM(verbose_level) \ 425 logging::ErrnoLogMessage(__FILE__, __LINE__, -verbose_level, \ 426 ::logging::GetLastSystemErrorCode()).stream() 427#endif 428 429#define VPLOG(verbose_level) \ 430 LAZY_STREAM(VPLOG_STREAM(verbose_level), VLOG_IS_ON(verbose_level)) 431 432#define VPLOG_IF(verbose_level, condition) \ 433 LAZY_STREAM(VPLOG_STREAM(verbose_level), \ 434 VLOG_IS_ON(verbose_level) && (condition)) 435 436// TODO(akalin): Add more VLOG variants, e.g. VPLOG. 437 438#define LOG_ASSERT(condition) \ 439 LOG_IF(FATAL, !(condition)) << "Assert failed: " #condition ". " 440#define SYSLOG_ASSERT(condition) \ 441 SYSLOG_IF(FATAL, !(condition)) << "Assert failed: " #condition ". " 442 443#if defined(OS_WIN) 444#define PLOG_STREAM(severity) \ 445 COMPACT_GOOGLE_LOG_EX_ ## severity(Win32ErrorLogMessage, \ 446 ::logging::GetLastSystemErrorCode()).stream() 447#elif defined(OS_POSIX) 448#define PLOG_STREAM(severity) \ 449 COMPACT_GOOGLE_LOG_EX_ ## severity(ErrnoLogMessage, \ 450 ::logging::GetLastSystemErrorCode()).stream() 451#endif 452 453#define PLOG(severity) \ 454 LAZY_STREAM(PLOG_STREAM(severity), LOG_IS_ON(severity)) 455 456#define PLOG_IF(severity, condition) \ 457 LAZY_STREAM(PLOG_STREAM(severity), LOG_IS_ON(severity) && (condition)) 458 459// The actual stream used isn't important. 460#define EAT_STREAM_PARAMETERS \ 461 true ? (void) 0 : ::logging::LogMessageVoidify() & LOG_STREAM(FATAL) 462 463// Captures the result of a CHECK_EQ (for example) and facilitates testing as a 464// boolean. 465class CheckOpResult { 466 public: 467 // |message| must be null if and only if the check failed. 468 CheckOpResult(std::string* message) : message_(message) {} 469 // Returns true if the check succeeded. 470 operator bool() const { return !message_; } 471 // Returns the message. 472 std::string* message() { return message_; } 473 474 private: 475 std::string* message_; 476}; 477 478// CHECK dies with a fatal error if condition is not true. It is *not* 479// controlled by NDEBUG, so the check will be executed regardless of 480// compilation mode. 481// 482// We make sure CHECK et al. always evaluates their arguments, as 483// doing CHECK(FunctionWithSideEffect()) is a common idiom. 484 485#if defined(OFFICIAL_BUILD) && defined(NDEBUG) && !defined(OS_ANDROID) 486 487// Make all CHECK functions discard their log strings to reduce code 488// bloat for official release builds (except Android). 489 490// TODO(akalin): This would be more valuable if there were some way to 491// remove BreakDebugger() from the backtrace, perhaps by turning it 492// into a macro (like __debugbreak() on Windows). 493#define CHECK(condition) \ 494 !(condition) ? ::base::debug::BreakDebugger() : EAT_STREAM_PARAMETERS 495 496#define PCHECK(condition) CHECK(condition) 497 498#define CHECK_OP(name, op, val1, val2) CHECK((val1) op (val2)) 499 500#else 501 502#if defined(_PREFAST_) && defined(OS_WIN) 503// Use __analysis_assume to tell the VC++ static analysis engine that 504// assert conditions are true, to suppress warnings. The LAZY_STREAM 505// parameter doesn't reference 'condition' in /analyze builds because 506// this evaluation confuses /analyze. The !! before condition is because 507// __analysis_assume gets confused on some conditions: 508// http://randomascii.wordpress.com/2011/09/13/analyze-for-visual-studio-the-ugly-part-5/ 509 510#define CHECK(condition) \ 511 __analysis_assume(!!(condition)), \ 512 LAZY_STREAM(LOG_STREAM(FATAL), false) \ 513 << "Check failed: " #condition ". " 514 515#define PCHECK(condition) \ 516 __analysis_assume(!!(condition)), \ 517 LAZY_STREAM(PLOG_STREAM(FATAL), false) \ 518 << "Check failed: " #condition ". " 519 520#else // _PREFAST_ 521 522// Do as much work as possible out of line to reduce inline code size. 523#define CHECK(condition) \ 524 LAZY_STREAM(logging::LogMessage(__FILE__, __LINE__, #condition).stream(), \ 525 !(condition)) 526 527#define PCHECK(condition) \ 528 LAZY_STREAM(PLOG_STREAM(FATAL), !(condition)) \ 529 << "Check failed: " #condition ". " 530 531#endif // _PREFAST_ 532 533// Helper macro for binary operators. 534// Don't use this macro directly in your code, use CHECK_EQ et al below. 535// The 'switch' is used to prevent the 'else' from being ambiguous when the 536// macro is used in an 'if' clause such as: 537// if (a == 1) 538// CHECK_EQ(2, a); 539#define CHECK_OP(name, op, val1, val2) \ 540 switch (0) case 0: default: \ 541 if (logging::CheckOpResult true_if_passed = \ 542 logging::Check##name##Impl((val1), (val2), \ 543 #val1 " " #op " " #val2)) \ 544 ; \ 545 else \ 546 logging::LogMessage(__FILE__, __LINE__, true_if_passed.message()).stream() 547 548#endif 549 550// Build the error message string. This is separate from the "Impl" 551// function template because it is not performance critical and so can 552// be out of line, while the "Impl" code should be inline. Caller 553// takes ownership of the returned string. 554template<class t1, class t2> 555std::string* MakeCheckOpString(const t1& v1, const t2& v2, const char* names) { 556 std::ostringstream ss; 557 ss << names << " (" << v1 << " vs. " << v2 << ")"; 558 std::string* msg = new std::string(ss.str()); 559 return msg; 560} 561 562// Commonly used instantiations of MakeCheckOpString<>. Explicitly instantiated 563// in logging.cc. 564extern template BASE_EXPORT std::string* MakeCheckOpString<int, int>( 565 const int&, const int&, const char* names); 566extern template BASE_EXPORT 567std::string* MakeCheckOpString<unsigned long, unsigned long>( 568 const unsigned long&, const unsigned long&, const char* names); 569extern template BASE_EXPORT 570std::string* MakeCheckOpString<unsigned long, unsigned int>( 571 const unsigned long&, const unsigned int&, const char* names); 572extern template BASE_EXPORT 573std::string* MakeCheckOpString<unsigned int, unsigned long>( 574 const unsigned int&, const unsigned long&, const char* names); 575extern template BASE_EXPORT 576std::string* MakeCheckOpString<std::string, std::string>( 577 const std::string&, const std::string&, const char* name); 578 579// Helper functions for CHECK_OP macro. 580// The (int, int) specialization works around the issue that the compiler 581// will not instantiate the template version of the function on values of 582// unnamed enum type - see comment below. 583#define DEFINE_CHECK_OP_IMPL(name, op) \ 584 template <class t1, class t2> \ 585 inline std::string* Check##name##Impl(const t1& v1, const t2& v2, \ 586 const char* names) { \ 587 if (v1 op v2) return NULL; \ 588 else return MakeCheckOpString(v1, v2, names); \ 589 } \ 590 inline std::string* Check##name##Impl(int v1, int v2, const char* names) { \ 591 if (v1 op v2) return NULL; \ 592 else return MakeCheckOpString(v1, v2, names); \ 593 } 594DEFINE_CHECK_OP_IMPL(EQ, ==) 595DEFINE_CHECK_OP_IMPL(NE, !=) 596DEFINE_CHECK_OP_IMPL(LE, <=) 597DEFINE_CHECK_OP_IMPL(LT, < ) 598DEFINE_CHECK_OP_IMPL(GE, >=) 599DEFINE_CHECK_OP_IMPL(GT, > ) 600#undef DEFINE_CHECK_OP_IMPL 601 602#define CHECK_EQ(val1, val2) CHECK_OP(EQ, ==, val1, val2) 603#define CHECK_NE(val1, val2) CHECK_OP(NE, !=, val1, val2) 604#define CHECK_LE(val1, val2) CHECK_OP(LE, <=, val1, val2) 605#define CHECK_LT(val1, val2) CHECK_OP(LT, < , val1, val2) 606#define CHECK_GE(val1, val2) CHECK_OP(GE, >=, val1, val2) 607#define CHECK_GT(val1, val2) CHECK_OP(GT, > , val1, val2) 608 609#if defined(NDEBUG) 610#define ENABLE_DLOG 0 611#else 612#define ENABLE_DLOG 1 613#endif 614 615#if defined(NDEBUG) && !defined(DCHECK_ALWAYS_ON) 616#define DCHECK_IS_ON() 0 617#else 618#define DCHECK_IS_ON() 1 619#endif 620 621// Definitions for DLOG et al. 622 623#if ENABLE_DLOG 624 625#define DLOG_IS_ON(severity) LOG_IS_ON(severity) 626#define DLOG_IF(severity, condition) LOG_IF(severity, condition) 627#define DLOG_ASSERT(condition) LOG_ASSERT(condition) 628#define DPLOG_IF(severity, condition) PLOG_IF(severity, condition) 629#define DVLOG_IF(verboselevel, condition) VLOG_IF(verboselevel, condition) 630#define DVPLOG_IF(verboselevel, condition) VPLOG_IF(verboselevel, condition) 631 632#else // ENABLE_DLOG 633 634// If ENABLE_DLOG is off, we want to avoid emitting any references to 635// |condition| (which may reference a variable defined only if NDEBUG 636// is not defined). Contrast this with DCHECK et al., which has 637// different behavior. 638 639#define DLOG_IS_ON(severity) false 640#define DLOG_IF(severity, condition) EAT_STREAM_PARAMETERS 641#define DLOG_ASSERT(condition) EAT_STREAM_PARAMETERS 642#define DPLOG_IF(severity, condition) EAT_STREAM_PARAMETERS 643#define DVLOG_IF(verboselevel, condition) EAT_STREAM_PARAMETERS 644#define DVPLOG_IF(verboselevel, condition) EAT_STREAM_PARAMETERS 645 646#endif // ENABLE_DLOG 647 648// DEBUG_MODE is for uses like 649// if (DEBUG_MODE) foo.CheckThatFoo(); 650// instead of 651// #ifndef NDEBUG 652// foo.CheckThatFoo(); 653// #endif 654// 655// We tie its state to ENABLE_DLOG. 656enum { DEBUG_MODE = ENABLE_DLOG }; 657 658#undef ENABLE_DLOG 659 660#define DLOG(severity) \ 661 LAZY_STREAM(LOG_STREAM(severity), DLOG_IS_ON(severity)) 662 663#define DPLOG(severity) \ 664 LAZY_STREAM(PLOG_STREAM(severity), DLOG_IS_ON(severity)) 665 666#define DVLOG(verboselevel) DVLOG_IF(verboselevel, VLOG_IS_ON(verboselevel)) 667 668#define DVPLOG(verboselevel) DVPLOG_IF(verboselevel, VLOG_IS_ON(verboselevel)) 669 670// Definitions for DCHECK et al. 671 672#if DCHECK_IS_ON() 673 674#define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \ 675 COMPACT_GOOGLE_LOG_EX_FATAL(ClassName , ##__VA_ARGS__) 676#define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_FATAL 677const LogSeverity LOG_DCHECK = LOG_FATAL; 678 679#else // DCHECK_IS_ON() 680 681// These are just dummy values. 682#define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \ 683 COMPACT_GOOGLE_LOG_EX_INFO(ClassName , ##__VA_ARGS__) 684#define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_INFO 685const LogSeverity LOG_DCHECK = LOG_INFO; 686 687#endif // DCHECK_IS_ON() 688 689// DCHECK et al. make sure to reference |condition| regardless of 690// whether DCHECKs are enabled; this is so that we don't get unused 691// variable warnings if the only use of a variable is in a DCHECK. 692// This behavior is different from DLOG_IF et al. 693 694#if defined(_PREFAST_) && defined(OS_WIN) 695// See comments on the previous use of __analysis_assume. 696 697#define DCHECK(condition) \ 698 __analysis_assume(!!(condition)), \ 699 LAZY_STREAM(LOG_STREAM(DCHECK), false) \ 700 << "Check failed: " #condition ". " 701 702#define DPCHECK(condition) \ 703 __analysis_assume(!!(condition)), \ 704 LAZY_STREAM(PLOG_STREAM(DCHECK), false) \ 705 << "Check failed: " #condition ". " 706 707#else // _PREFAST_ 708 709#define DCHECK(condition) \ 710 LAZY_STREAM(LOG_STREAM(DCHECK), DCHECK_IS_ON() ? !(condition) : false) \ 711 << "Check failed: " #condition ". " 712 713#define DPCHECK(condition) \ 714 LAZY_STREAM(PLOG_STREAM(DCHECK), DCHECK_IS_ON() ? !(condition) : false) \ 715 << "Check failed: " #condition ". " 716 717#endif // _PREFAST_ 718 719// Helper macro for binary operators. 720// Don't use this macro directly in your code, use DCHECK_EQ et al below. 721// The 'switch' is used to prevent the 'else' from being ambiguous when the 722// macro is used in an 'if' clause such as: 723// if (a == 1) 724// DCHECK_EQ(2, a); 725#define DCHECK_OP(name, op, val1, val2) \ 726 switch (0) case 0: default: \ 727 if (logging::CheckOpResult true_if_passed = \ 728 DCHECK_IS_ON() ? \ 729 logging::Check##name##Impl((val1), (val2), \ 730 #val1 " " #op " " #val2) : nullptr) \ 731 ; \ 732 else \ 733 logging::LogMessage(__FILE__, __LINE__, ::logging::LOG_DCHECK, \ 734 true_if_passed.message()).stream() 735 736// Equality/Inequality checks - compare two values, and log a 737// LOG_DCHECK message including the two values when the result is not 738// as expected. The values must have operator<<(ostream, ...) 739// defined. 740// 741// You may append to the error message like so: 742// DCHECK_NE(1, 2) << ": The world must be ending!"; 743// 744// We are very careful to ensure that each argument is evaluated exactly 745// once, and that anything which is legal to pass as a function argument is 746// legal here. In particular, the arguments may be temporary expressions 747// which will end up being destroyed at the end of the apparent statement, 748// for example: 749// DCHECK_EQ(string("abc")[1], 'b'); 750// 751// WARNING: These may not compile correctly if one of the arguments is a pointer 752// and the other is NULL. To work around this, simply static_cast NULL to the 753// type of the desired pointer. 754 755#define DCHECK_EQ(val1, val2) DCHECK_OP(EQ, ==, val1, val2) 756#define DCHECK_NE(val1, val2) DCHECK_OP(NE, !=, val1, val2) 757#define DCHECK_LE(val1, val2) DCHECK_OP(LE, <=, val1, val2) 758#define DCHECK_LT(val1, val2) DCHECK_OP(LT, < , val1, val2) 759#define DCHECK_GE(val1, val2) DCHECK_OP(GE, >=, val1, val2) 760#define DCHECK_GT(val1, val2) DCHECK_OP(GT, > , val1, val2) 761 762#if !DCHECK_IS_ON() && defined(OS_CHROMEOS) 763// Implement logging of NOTREACHED() as a dedicated function to get function 764// call overhead down to a minimum. 765void LogErrorNotReached(const char* file, int line); 766#define NOTREACHED() \ 767 true ? ::logging::LogErrorNotReached(__FILE__, __LINE__) \ 768 : EAT_STREAM_PARAMETERS 769#else 770#define NOTREACHED() DCHECK(false) 771#endif 772 773// Redefine the standard assert to use our nice log files 774#undef assert 775#define assert(x) DLOG_ASSERT(x) 776 777// This class more or less represents a particular log message. You 778// create an instance of LogMessage and then stream stuff to it. 779// When you finish streaming to it, ~LogMessage is called and the 780// full message gets streamed to the appropriate destination. 781// 782// You shouldn't actually use LogMessage's constructor to log things, 783// though. You should use the LOG() macro (and variants thereof) 784// above. 785class BASE_EXPORT LogMessage { 786 public: 787 // Used for LOG(severity). 788 LogMessage(const char* file, int line, LogSeverity severity); 789 790 // Used for CHECK(). Implied severity = LOG_FATAL. 791 LogMessage(const char* file, int line, const char* condition); 792 793 // Used for CHECK_EQ(), etc. Takes ownership of the given string. 794 // Implied severity = LOG_FATAL. 795 LogMessage(const char* file, int line, std::string* result); 796 797 // Used for DCHECK_EQ(), etc. Takes ownership of the given string. 798 LogMessage(const char* file, int line, LogSeverity severity, 799 std::string* result); 800 801 ~LogMessage(); 802 803 std::ostream& stream() { return stream_; } 804 805 private: 806 void Init(const char* file, int line); 807 808 LogSeverity severity_; 809 std::ostringstream stream_; 810 size_t message_start_; // Offset of the start of the message (past prefix 811 // info). 812 // The file and line information passed in to the constructor. 813 const char* file_; 814 const int line_; 815 816#if defined(OS_WIN) 817 // Stores the current value of GetLastError in the constructor and restores 818 // it in the destructor by calling SetLastError. 819 // This is useful since the LogMessage class uses a lot of Win32 calls 820 // that will lose the value of GLE and the code that called the log function 821 // will have lost the thread error value when the log call returns. 822 class SaveLastError { 823 public: 824 SaveLastError(); 825 ~SaveLastError(); 826 827 unsigned long get_error() const { return last_error_; } 828 829 protected: 830 unsigned long last_error_; 831 }; 832 833 SaveLastError last_error_; 834#endif 835 836 DISALLOW_COPY_AND_ASSIGN(LogMessage); 837}; 838 839// A non-macro interface to the log facility; (useful 840// when the logging level is not a compile-time constant). 841inline void LogAtLevel(int log_level, const std::string& msg) { 842 LogMessage(__FILE__, __LINE__, log_level).stream() << msg; 843} 844 845// This class is used to explicitly ignore values in the conditional 846// logging macros. This avoids compiler warnings like "value computed 847// is not used" and "statement has no effect". 848class LogMessageVoidify { 849 public: 850 LogMessageVoidify() { } 851 // This has to be an operator with a precedence lower than << but 852 // higher than ?: 853 void operator&(std::ostream&) { } 854}; 855 856#if defined(OS_WIN) 857typedef unsigned long SystemErrorCode; 858#elif defined(OS_POSIX) 859typedef int SystemErrorCode; 860#endif 861 862// Alias for ::GetLastError() on Windows and errno on POSIX. Avoids having to 863// pull in windows.h just for GetLastError() and DWORD. 864BASE_EXPORT SystemErrorCode GetLastSystemErrorCode(); 865BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code); 866 867#if defined(OS_WIN) 868// Appends a formatted system message of the GetLastError() type. 869class BASE_EXPORT Win32ErrorLogMessage { 870 public: 871 Win32ErrorLogMessage(const char* file, 872 int line, 873 LogSeverity severity, 874 SystemErrorCode err); 875 876 // Appends the error message before destructing the encapsulated class. 877 ~Win32ErrorLogMessage(); 878 879 std::ostream& stream() { return log_message_.stream(); } 880 881 private: 882 SystemErrorCode err_; 883 LogMessage log_message_; 884 885 DISALLOW_COPY_AND_ASSIGN(Win32ErrorLogMessage); 886}; 887#elif defined(OS_POSIX) 888// Appends a formatted system message of the errno type 889class BASE_EXPORT ErrnoLogMessage { 890 public: 891 ErrnoLogMessage(const char* file, 892 int line, 893 LogSeverity severity, 894 SystemErrorCode err); 895 896 // Appends the error message before destructing the encapsulated class. 897 ~ErrnoLogMessage(); 898 899 std::ostream& stream() { return log_message_.stream(); } 900 901 private: 902 SystemErrorCode err_; 903 LogMessage log_message_; 904 905 DISALLOW_COPY_AND_ASSIGN(ErrnoLogMessage); 906}; 907#endif // OS_WIN 908 909// Closes the log file explicitly if open. 910// NOTE: Since the log file is opened as necessary by the action of logging 911// statements, there's no guarantee that it will stay closed 912// after this call. 913BASE_EXPORT void CloseLogFile(); 914 915// Async signal safe logging mechanism. 916BASE_EXPORT void RawLog(int level, const char* message); 917 918#define RAW_LOG(level, message) logging::RawLog(logging::LOG_ ## level, message) 919 920#define RAW_CHECK(condition) \ 921 do { \ 922 if (!(condition)) \ 923 logging::RawLog(logging::LOG_FATAL, "Check failed: " #condition "\n"); \ 924 } while (0) 925 926#if defined(OS_WIN) 927// Returns true if logging to file is enabled. 928BASE_EXPORT bool IsLoggingToFileEnabled(); 929 930// Returns the default log file path. 931BASE_EXPORT std::wstring GetLogFileFullPath(); 932#endif 933 934} // namespace logging 935 936// The NOTIMPLEMENTED() macro annotates codepaths which have 937// not been implemented yet. 938// 939// The implementation of this macro is controlled by NOTIMPLEMENTED_POLICY: 940// 0 -- Do nothing (stripped by compiler) 941// 1 -- Warn at compile time 942// 2 -- Fail at compile time 943// 3 -- Fail at runtime (DCHECK) 944// 4 -- [default] LOG(ERROR) at runtime 945// 5 -- LOG(ERROR) at runtime, only once per call-site 946 947#ifndef NOTIMPLEMENTED_POLICY 948#if defined(OS_ANDROID) && defined(OFFICIAL_BUILD) 949#define NOTIMPLEMENTED_POLICY 0 950#else 951// Select default policy: LOG(ERROR) 952#define NOTIMPLEMENTED_POLICY 4 953#endif 954#endif 955 956#if defined(COMPILER_GCC) 957// On Linux, with GCC, we can use __PRETTY_FUNCTION__ to get the demangled name 958// of the current function in the NOTIMPLEMENTED message. 959#define NOTIMPLEMENTED_MSG "Not implemented reached in " << __PRETTY_FUNCTION__ 960#else 961#define NOTIMPLEMENTED_MSG "NOT IMPLEMENTED" 962#endif 963 964#if NOTIMPLEMENTED_POLICY == 0 965#define NOTIMPLEMENTED() EAT_STREAM_PARAMETERS 966#elif NOTIMPLEMENTED_POLICY == 1 967// TODO, figure out how to generate a warning 968#define NOTIMPLEMENTED() static_assert(false, "NOT_IMPLEMENTED") 969#elif NOTIMPLEMENTED_POLICY == 2 970#define NOTIMPLEMENTED() static_assert(false, "NOT_IMPLEMENTED") 971#elif NOTIMPLEMENTED_POLICY == 3 972#define NOTIMPLEMENTED() NOTREACHED() 973#elif NOTIMPLEMENTED_POLICY == 4 974#define NOTIMPLEMENTED() LOG(ERROR) << NOTIMPLEMENTED_MSG 975#elif NOTIMPLEMENTED_POLICY == 5 976#define NOTIMPLEMENTED() do {\ 977 static bool logged_once = false;\ 978 LOG_IF(ERROR, !logged_once) << NOTIMPLEMENTED_MSG;\ 979 logged_once = true;\ 980} while(0);\ 981EAT_STREAM_PARAMETERS 982#endif 983 984#endif // BASE_LOGGING_H_ 985