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. 149 namespace 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. 156 BASE_EXPORT std::ostream& operator<<(std::ostream& out, const wchar_t* wstr); 157 inline std::ostream& operator<<(std::ostream& out, const std::wstring& wstr) { 158 return out << wstr.c_str(); 159 } 160 161 template<typename T> 162 typename 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 168 169 namespace logging { 170 171 // TODO(avi): do we want to do a unification of character types here? 172 #if defined(OS_WIN) 173 typedef wchar_t PathChar; 174 #else 175 typedef char PathChar; 176 #endif 177 178 // Where to record logging output? A flat file and/or system debug log 179 // via OutputDebugString. 180 enum 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. 204 enum 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. 208 enum OldFileDeletionState { DELETE_OLD_LOG_FILE, APPEND_TO_OLD_LOG_FILE }; 209 210 struct 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". 241 BASE_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. 257 inline 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. 267 BASE_EXPORT void SetMinLogLevel(int level); 268 269 // Gets the current log level. 270 BASE_EXPORT int GetMinLogLevel(); 271 272 // Used by LOG_IS_ON to lazy-evaluate stream arguments. 273 BASE_EXPORT bool ShouldCreateLogMessage(int severity); 274 275 // Gets the VLOG default verbosity level. 276 BASE_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. 282 BASE_EXPORT int GetVlogLevelHelper(const char* file_start, size_t N); 283 284 template <size_t N> 285 int 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. 293 BASE_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. 299 BASE_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) 305 typedef void (*LogAssertHandlerFunction)(const std::string& str); 306 BASE_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. 312 typedef bool (*LogMessageHandlerFunction)(int severity, 313 const char* file, int line, size_t message_start, const std::string& str); 314 BASE_EXPORT void SetLogMessageHandler(LogMessageHandlerFunction handler); 315 BASE_EXPORT LogMessageHandlerFunction GetLogMessageHandler(); 316 317 typedef int LogSeverity; 318 const 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. 321 const LogSeverity LOG_INFO = 0; 322 const LogSeverity LOG_WARNING = 1; 323 const LogSeverity LOG_ERROR = 2; 324 const LogSeverity LOG_FATAL = 3; 325 const LogSeverity LOG_NUM_SEVERITIES = 4; 326 327 // LOG_DFATAL is LOG_FATAL in debug mode, ERROR in normal mode 328 #ifdef NDEBUG 329 const LogSeverity LOG_DFATAL = LOG_ERROR; 330 #else 331 const 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). 370 const 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. 465 class 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. 554 template<class t1, class t2> 555 std::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. 564 extern template BASE_EXPORT std::string* MakeCheckOpString<int, int>( 565 const int&, const int&, const char* names); 566 extern template BASE_EXPORT 567 std::string* MakeCheckOpString<unsigned long, unsigned long>( 568 const unsigned long&, const unsigned long&, const char* names); 569 extern template BASE_EXPORT 570 std::string* MakeCheckOpString<unsigned long, unsigned int>( 571 const unsigned long&, const unsigned int&, const char* names); 572 extern template BASE_EXPORT 573 std::string* MakeCheckOpString<unsigned int, unsigned long>( 574 const unsigned int&, const unsigned long&, const char* names); 575 extern template BASE_EXPORT 576 std::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 } 594 DEFINE_CHECK_OP_IMPL(EQ, ==) 595 DEFINE_CHECK_OP_IMPL(NE, !=) 596 DEFINE_CHECK_OP_IMPL(LE, <=) 597 DEFINE_CHECK_OP_IMPL(LT, < ) 598 DEFINE_CHECK_OP_IMPL(GE, >=) 599 DEFINE_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. 656 enum { 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 677 const 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 685 const 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. 765 void 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. 785 class 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). 841 inline 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". 848 class 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) 857 typedef unsigned long SystemErrorCode; 858 #elif defined(OS_POSIX) 859 typedef 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. 864 BASE_EXPORT SystemErrorCode GetLastSystemErrorCode(); 865 BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code); 866 867 #if defined(OS_WIN) 868 // Appends a formatted system message of the GetLastError() type. 869 class 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 889 class 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. 913 BASE_EXPORT void CloseLogFile(); 914 915 // Async signal safe logging mechanism. 916 BASE_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. 928 BASE_EXPORT bool IsLoggingToFileEnabled(); 929 930 // Returns the default log file path. 931 BASE_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);\ 981 EAT_STREAM_PARAMETERS 982 #endif 983 984 #endif // BASE_LOGGING_H_ 985
