logging.h revision 2a99a7e74a7f215066514fe81d2bfa6639d9eddd
1// Copyright (c) 2012 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5#ifndef BASE_LOGGING_H_ 6#define BASE_LOGGING_H_ 7 8#include <cassert> 9#include <string> 10#include <cstring> 11#include <sstream> 12 13#include "base/base_export.h" 14#include "base/basictypes.h" 15#include "base/debug/debugger.h" 16#include "build/build_config.h" 17 18// 19// Optional message capabilities 20// ----------------------------- 21// Assertion failed messages and fatal errors are displayed in a dialog box 22// before the application exits. However, running this UI creates a message 23// loop, which causes application messages to be processed and potentially 24// dispatched to existing application windows. Since the application is in a 25// bad state when this assertion dialog is displayed, these messages may not 26// get processed and hang the dialog, or the application might go crazy. 27// 28// Therefore, it can be beneficial to display the error dialog in a separate 29// process from the main application. When the logging system needs to display 30// a fatal error dialog box, it will look for a program called 31// "DebugMessage.exe" in the same directory as the application executable. It 32// will run this application with the message as the command line, and will 33// not include the name of the application as is traditional for easier 34// parsing. 35// 36// The code for DebugMessage.exe is only one line. In WinMain, do: 37// MessageBox(NULL, GetCommandLineW(), L"Fatal Error", 0); 38// 39// If DebugMessage.exe is not found, the logging code will use a normal 40// MessageBox, potentially causing the problems discussed above. 41 42 43// Instructions 44// ------------ 45// 46// Make a bunch of macros for logging. The way to log things is to stream 47// things to LOG(<a particular severity level>). E.g., 48// 49// LOG(INFO) << "Found " << num_cookies << " cookies"; 50// 51// You can also do conditional logging: 52// 53// LOG_IF(INFO, num_cookies > 10) << "Got lots of cookies"; 54// 55// The above will cause log messages to be output on the 1st, 11th, 21st, ... 56// times it is executed. Note that the special COUNTER value is used to 57// identify which repetition is happening. 58// 59// The CHECK(condition) macro is active in both debug and release builds and 60// effectively performs a LOG(FATAL) which terminates the process and 61// generates a crashdump unless a debugger is attached. 62// 63// There are also "debug mode" logging macros like the ones above: 64// 65// DLOG(INFO) << "Found cookies"; 66// 67// DLOG_IF(INFO, num_cookies > 10) << "Got lots of cookies"; 68// 69// All "debug mode" logging is compiled away to nothing for non-debug mode 70// compiles. LOG_IF and development flags also work well together 71// because the code can be compiled away sometimes. 72// 73// We also have 74// 75// LOG_ASSERT(assertion); 76// DLOG_ASSERT(assertion); 77// 78// which is syntactic sugar for {,D}LOG_IF(FATAL, assert fails) << assertion; 79// 80// There are "verbose level" logging macros. They look like 81// 82// VLOG(1) << "I'm printed when you run the program with --v=1 or more"; 83// VLOG(2) << "I'm printed when you run the program with --v=2 or more"; 84// 85// These always log at the INFO log level (when they log at all). 86// The verbose logging can also be turned on module-by-module. For instance, 87// --vmodule=profile=2,icon_loader=1,browser_*=3,*/chromeos/*=4 --v=0 88// will cause: 89// a. VLOG(2) and lower messages to be printed from profile.{h,cc} 90// b. VLOG(1) and lower messages to be printed from icon_loader.{h,cc} 91// c. VLOG(3) and lower messages to be printed from files prefixed with 92// "browser" 93// d. VLOG(4) and lower messages to be printed from files under a 94// "chromeos" directory. 95// e. VLOG(0) and lower messages to be printed from elsewhere 96// 97// The wildcarding functionality shown by (c) supports both '*' (match 98// 0 or more characters) and '?' (match any single character) 99// wildcards. Any pattern containing a forward or backward slash will 100// be tested against the whole pathname and not just the module. 101// E.g., "*/foo/bar/*=2" would change the logging level for all code 102// in source files under a "foo/bar" directory. 103// 104// There's also VLOG_IS_ON(n) "verbose level" condition macro. To be used as 105// 106// if (VLOG_IS_ON(2)) { 107// // do some logging preparation and logging 108// // that can't be accomplished with just VLOG(2) << ...; 109// } 110// 111// There is also a VLOG_IF "verbose level" condition macro for sample 112// cases, when some extra computation and preparation for logs is not 113// needed. 114// 115// VLOG_IF(1, (size > 1024)) 116// << "I'm printed when size is more than 1024 and when you run the " 117// "program with --v=1 or more"; 118// 119// We also override the standard 'assert' to use 'DLOG_ASSERT'. 120// 121// Lastly, there is: 122// 123// PLOG(ERROR) << "Couldn't do foo"; 124// DPLOG(ERROR) << "Couldn't do foo"; 125// PLOG_IF(ERROR, cond) << "Couldn't do foo"; 126// DPLOG_IF(ERROR, cond) << "Couldn't do foo"; 127// PCHECK(condition) << "Couldn't do foo"; 128// DPCHECK(condition) << "Couldn't do foo"; 129// 130// which append the last system error to the message in string form (taken from 131// GetLastError() on Windows and errno on POSIX). 132// 133// The supported severity levels for macros that allow you to specify one 134// are (in increasing order of severity) INFO, WARNING, ERROR, ERROR_REPORT, 135// and FATAL. 136// 137// Very important: logging a message at the FATAL severity level causes 138// the program to terminate (after the message is logged). 139// 140// Note the special severity of ERROR_REPORT only available/relevant in normal 141// mode, which displays error dialog without terminating the program. There is 142// no error dialog for severity ERROR or below in normal mode. 143// 144// There is also the special severity of DFATAL, which logs FATAL in 145// debug mode, ERROR in normal mode. 146 147namespace logging { 148 149// Where to record logging output? A flat file and/or system debug log via 150// OutputDebugString. Defaults on Windows to LOG_ONLY_TO_FILE, and on 151// POSIX to LOG_ONLY_TO_SYSTEM_DEBUG_LOG (aka stderr). 152enum LoggingDestination { LOG_NONE, 153 LOG_ONLY_TO_FILE, 154 LOG_ONLY_TO_SYSTEM_DEBUG_LOG, 155 LOG_TO_BOTH_FILE_AND_SYSTEM_DEBUG_LOG }; 156 157// Indicates that the log file should be locked when being written to. 158// Often, there is no locking, which is fine for a single threaded program. 159// If logging is being done from multiple threads or there can be more than 160// one process doing the logging, the file should be locked during writes to 161// make each log outut atomic. Other writers will block. 162// 163// All processes writing to the log file must have their locking set for it to 164// work properly. Defaults to DONT_LOCK_LOG_FILE. 165enum LogLockingState { LOCK_LOG_FILE, DONT_LOCK_LOG_FILE }; 166 167// On startup, should we delete or append to an existing log file (if any)? 168// Defaults to APPEND_TO_OLD_LOG_FILE. 169enum OldFileDeletionState { DELETE_OLD_LOG_FILE, APPEND_TO_OLD_LOG_FILE }; 170 171enum DcheckState { 172 DISABLE_DCHECK_FOR_NON_OFFICIAL_RELEASE_BUILDS, 173 ENABLE_DCHECK_FOR_NON_OFFICIAL_RELEASE_BUILDS 174}; 175 176// TODO(avi): do we want to do a unification of character types here? 177#if defined(OS_WIN) 178typedef wchar_t PathChar; 179#else 180typedef char PathChar; 181#endif 182 183// Define different names for the BaseInitLoggingImpl() function depending on 184// whether NDEBUG is defined or not so that we'll fail to link if someone tries 185// to compile logging.cc with NDEBUG but includes logging.h without defining it, 186// or vice versa. 187#if NDEBUG 188#define BaseInitLoggingImpl BaseInitLoggingImpl_built_with_NDEBUG 189#else 190#define BaseInitLoggingImpl BaseInitLoggingImpl_built_without_NDEBUG 191#endif 192 193// Implementation of the InitLogging() method declared below. We use a 194// more-specific name so we can #define it above without affecting other code 195// that has named stuff "InitLogging". 196BASE_EXPORT bool BaseInitLoggingImpl(const PathChar* log_file, 197 LoggingDestination logging_dest, 198 LogLockingState lock_log, 199 OldFileDeletionState delete_old, 200 DcheckState dcheck_state); 201 202// Sets the log file name and other global logging state. Calling this function 203// is recommended, and is normally done at the beginning of application init. 204// If you don't call it, all the flags will be initialized to their default 205// values, and there is a race condition that may leak a critical section 206// object if two threads try to do the first log at the same time. 207// See the definition of the enums above for descriptions and default values. 208// 209// The default log file is initialized to "debug.log" in the application 210// directory. You probably don't want this, especially since the program 211// directory may not be writable on an enduser's system. 212// 213// This function may be called a second time to re-direct logging (e.g after 214// loging in to a user partition), however it should never be called more than 215// twice. 216inline bool InitLogging(const PathChar* log_file, 217 LoggingDestination logging_dest, 218 LogLockingState lock_log, 219 OldFileDeletionState delete_old, 220 DcheckState dcheck_state) { 221 return BaseInitLoggingImpl(log_file, logging_dest, lock_log, 222 delete_old, dcheck_state); 223} 224 225// Sets the log level. Anything at or above this level will be written to the 226// log file/displayed to the user (if applicable). Anything below this level 227// will be silently ignored. The log level defaults to 0 (everything is logged 228// up to level INFO) if this function is not called. 229// Note that log messages for VLOG(x) are logged at level -x, so setting 230// the min log level to negative values enables verbose logging. 231BASE_EXPORT void SetMinLogLevel(int level); 232 233// Gets the current log level. 234BASE_EXPORT int GetMinLogLevel(); 235 236// Gets the VLOG default verbosity level. 237BASE_EXPORT int GetVlogVerbosity(); 238 239// Gets the current vlog level for the given file (usually taken from 240// __FILE__). 241 242// Note that |N| is the size *with* the null terminator. 243BASE_EXPORT int GetVlogLevelHelper(const char* file_start, size_t N); 244 245template <size_t N> 246int GetVlogLevel(const char (&file)[N]) { 247 return GetVlogLevelHelper(file, N); 248} 249 250// Sets the common items you want to be prepended to each log message. 251// process and thread IDs default to off, the timestamp defaults to on. 252// If this function is not called, logging defaults to writing the timestamp 253// only. 254BASE_EXPORT void SetLogItems(bool enable_process_id, bool enable_thread_id, 255 bool enable_timestamp, bool enable_tickcount); 256 257// Sets whether or not you'd like to see fatal debug messages popped up in 258// a dialog box or not. 259// Dialogs are not shown by default. 260BASE_EXPORT void SetShowErrorDialogs(bool enable_dialogs); 261 262// Sets the Log Assert Handler that will be used to notify of check failures. 263// The default handler shows a dialog box and then terminate the process, 264// however clients can use this function to override with their own handling 265// (e.g. a silent one for Unit Tests) 266typedef void (*LogAssertHandlerFunction)(const std::string& str); 267BASE_EXPORT void SetLogAssertHandler(LogAssertHandlerFunction handler); 268 269// Sets the Log Report Handler that will be used to notify of check failures 270// in non-debug mode. The default handler shows a dialog box and continues 271// the execution, however clients can use this function to override with their 272// own handling. 273typedef void (*LogReportHandlerFunction)(const std::string& str); 274BASE_EXPORT void SetLogReportHandler(LogReportHandlerFunction handler); 275 276// Sets the Log Message Handler that gets passed every log message before 277// it's sent to other log destinations (if any). 278// Returns true to signal that it handled the message and the message 279// should not be sent to other log destinations. 280typedef bool (*LogMessageHandlerFunction)(int severity, 281 const char* file, int line, size_t message_start, const std::string& str); 282BASE_EXPORT void SetLogMessageHandler(LogMessageHandlerFunction handler); 283BASE_EXPORT LogMessageHandlerFunction GetLogMessageHandler(); 284 285typedef int LogSeverity; 286const LogSeverity LOG_VERBOSE = -1; // This is level 1 verbosity 287// Note: the log severities are used to index into the array of names, 288// see log_severity_names. 289const LogSeverity LOG_INFO = 0; 290const LogSeverity LOG_WARNING = 1; 291const LogSeverity LOG_ERROR = 2; 292const LogSeverity LOG_ERROR_REPORT = 3; 293const LogSeverity LOG_FATAL = 4; 294const LogSeverity LOG_NUM_SEVERITIES = 5; 295 296// LOG_DFATAL is LOG_FATAL in debug mode, ERROR in normal mode 297#ifdef NDEBUG 298const LogSeverity LOG_DFATAL = LOG_ERROR; 299#else 300const LogSeverity LOG_DFATAL = LOG_FATAL; 301#endif 302 303// A few definitions of macros that don't generate much code. These are used 304// by LOG() and LOG_IF, etc. Since these are used all over our code, it's 305// better to have compact code for these operations. 306#define COMPACT_GOOGLE_LOG_EX_INFO(ClassName, ...) \ 307 logging::ClassName(__FILE__, __LINE__, logging::LOG_INFO , ##__VA_ARGS__) 308#define COMPACT_GOOGLE_LOG_EX_WARNING(ClassName, ...) \ 309 logging::ClassName(__FILE__, __LINE__, logging::LOG_WARNING , ##__VA_ARGS__) 310#define COMPACT_GOOGLE_LOG_EX_ERROR(ClassName, ...) \ 311 logging::ClassName(__FILE__, __LINE__, logging::LOG_ERROR , ##__VA_ARGS__) 312#define COMPACT_GOOGLE_LOG_EX_ERROR_REPORT(ClassName, ...) \ 313 logging::ClassName(__FILE__, __LINE__, \ 314 logging::LOG_ERROR_REPORT , ##__VA_ARGS__) 315#define COMPACT_GOOGLE_LOG_EX_FATAL(ClassName, ...) \ 316 logging::ClassName(__FILE__, __LINE__, logging::LOG_FATAL , ##__VA_ARGS__) 317#define COMPACT_GOOGLE_LOG_EX_DFATAL(ClassName, ...) \ 318 logging::ClassName(__FILE__, __LINE__, logging::LOG_DFATAL , ##__VA_ARGS__) 319 320#define COMPACT_GOOGLE_LOG_INFO \ 321 COMPACT_GOOGLE_LOG_EX_INFO(LogMessage) 322#define COMPACT_GOOGLE_LOG_WARNING \ 323 COMPACT_GOOGLE_LOG_EX_WARNING(LogMessage) 324#define COMPACT_GOOGLE_LOG_ERROR \ 325 COMPACT_GOOGLE_LOG_EX_ERROR(LogMessage) 326#define COMPACT_GOOGLE_LOG_ERROR_REPORT \ 327 COMPACT_GOOGLE_LOG_EX_ERROR_REPORT(LogMessage) 328#define COMPACT_GOOGLE_LOG_FATAL \ 329 COMPACT_GOOGLE_LOG_EX_FATAL(LogMessage) 330#define COMPACT_GOOGLE_LOG_DFATAL \ 331 COMPACT_GOOGLE_LOG_EX_DFATAL(LogMessage) 332 333#if defined(OS_WIN) 334// wingdi.h defines ERROR to be 0. When we call LOG(ERROR), it gets 335// substituted with 0, and it expands to COMPACT_GOOGLE_LOG_0. To allow us 336// to keep using this syntax, we define this macro to do the same thing 337// as COMPACT_GOOGLE_LOG_ERROR, and also define ERROR the same way that 338// the Windows SDK does for consistency. 339#define ERROR 0 340#define COMPACT_GOOGLE_LOG_EX_0(ClassName, ...) \ 341 COMPACT_GOOGLE_LOG_EX_ERROR(ClassName , ##__VA_ARGS__) 342#define COMPACT_GOOGLE_LOG_0 COMPACT_GOOGLE_LOG_ERROR 343// Needed for LOG_IS_ON(ERROR). 344const LogSeverity LOG_0 = LOG_ERROR; 345#endif 346 347// As special cases, we can assume that LOG_IS_ON(ERROR_REPORT) and 348// LOG_IS_ON(FATAL) always hold. Also, LOG_IS_ON(DFATAL) always holds 349// in debug mode. In particular, CHECK()s will always fire if they 350// fail. 351#define LOG_IS_ON(severity) \ 352 ((::logging::LOG_ ## severity) >= ::logging::GetMinLogLevel()) 353 354// We can't do any caching tricks with VLOG_IS_ON() like the 355// google-glog version since it requires GCC extensions. This means 356// that using the v-logging functions in conjunction with --vmodule 357// may be slow. 358#define VLOG_IS_ON(verboselevel) \ 359 ((verboselevel) <= ::logging::GetVlogLevel(__FILE__)) 360 361// Helper macro which avoids evaluating the arguments to a stream if 362// the condition doesn't hold. 363#define LAZY_STREAM(stream, condition) \ 364 !(condition) ? (void) 0 : ::logging::LogMessageVoidify() & (stream) 365 366// We use the preprocessor's merging operator, "##", so that, e.g., 367// LOG(INFO) becomes the token COMPACT_GOOGLE_LOG_INFO. There's some funny 368// subtle difference between ostream member streaming functions (e.g., 369// ostream::operator<<(int) and ostream non-member streaming functions 370// (e.g., ::operator<<(ostream&, string&): it turns out that it's 371// impossible to stream something like a string directly to an unnamed 372// ostream. We employ a neat hack by calling the stream() member 373// function of LogMessage which seems to avoid the problem. 374#define LOG_STREAM(severity) COMPACT_GOOGLE_LOG_ ## severity.stream() 375 376#define LOG(severity) LAZY_STREAM(LOG_STREAM(severity), LOG_IS_ON(severity)) 377#define LOG_IF(severity, condition) \ 378 LAZY_STREAM(LOG_STREAM(severity), LOG_IS_ON(severity) && (condition)) 379 380#define SYSLOG(severity) LOG(severity) 381#define SYSLOG_IF(severity, condition) LOG_IF(severity, condition) 382 383// The VLOG macros log with negative verbosities. 384#define VLOG_STREAM(verbose_level) \ 385 logging::LogMessage(__FILE__, __LINE__, -verbose_level).stream() 386 387#define VLOG(verbose_level) \ 388 LAZY_STREAM(VLOG_STREAM(verbose_level), VLOG_IS_ON(verbose_level)) 389 390#define VLOG_IF(verbose_level, condition) \ 391 LAZY_STREAM(VLOG_STREAM(verbose_level), \ 392 VLOG_IS_ON(verbose_level) && (condition)) 393 394#if defined (OS_WIN) 395#define VPLOG_STREAM(verbose_level) \ 396 logging::Win32ErrorLogMessage(__FILE__, __LINE__, -verbose_level, \ 397 ::logging::GetLastSystemErrorCode()).stream() 398#elif defined(OS_POSIX) 399#define VPLOG_STREAM(verbose_level) \ 400 logging::ErrnoLogMessage(__FILE__, __LINE__, -verbose_level, \ 401 ::logging::GetLastSystemErrorCode()).stream() 402#endif 403 404#define VPLOG(verbose_level) \ 405 LAZY_STREAM(VPLOG_STREAM(verbose_level), VLOG_IS_ON(verbose_level)) 406 407#define VPLOG_IF(verbose_level, condition) \ 408 LAZY_STREAM(VPLOG_STREAM(verbose_level), \ 409 VLOG_IS_ON(verbose_level) && (condition)) 410 411// TODO(akalin): Add more VLOG variants, e.g. VPLOG. 412 413#define LOG_ASSERT(condition) \ 414 LOG_IF(FATAL, !(condition)) << "Assert failed: " #condition ". " 415#define SYSLOG_ASSERT(condition) \ 416 SYSLOG_IF(FATAL, !(condition)) << "Assert failed: " #condition ". " 417 418#if defined(OS_WIN) 419#define LOG_GETLASTERROR_STREAM(severity) \ 420 COMPACT_GOOGLE_LOG_EX_ ## severity(Win32ErrorLogMessage, \ 421 ::logging::GetLastSystemErrorCode()).stream() 422#define LOG_GETLASTERROR(severity) \ 423 LAZY_STREAM(LOG_GETLASTERROR_STREAM(severity), LOG_IS_ON(severity)) 424#define LOG_GETLASTERROR_MODULE_STREAM(severity, module) \ 425 COMPACT_GOOGLE_LOG_EX_ ## severity(Win32ErrorLogMessage, \ 426 ::logging::GetLastSystemErrorCode(), module).stream() 427#define LOG_GETLASTERROR_MODULE(severity, module) \ 428 LAZY_STREAM(LOG_GETLASTERROR_STREAM(severity, module), \ 429 LOG_IS_ON(severity)) 430// PLOG_STREAM is used by PLOG, which is the usual error logging macro 431// for each platform. 432#define PLOG_STREAM(severity) LOG_GETLASTERROR_STREAM(severity) 433#elif defined(OS_POSIX) 434#define LOG_ERRNO_STREAM(severity) \ 435 COMPACT_GOOGLE_LOG_EX_ ## severity(ErrnoLogMessage, \ 436 ::logging::GetLastSystemErrorCode()).stream() 437#define LOG_ERRNO(severity) \ 438 LAZY_STREAM(LOG_ERRNO_STREAM(severity), LOG_IS_ON(severity)) 439// PLOG_STREAM is used by PLOG, which is the usual error logging macro 440// for each platform. 441#define PLOG_STREAM(severity) LOG_ERRNO_STREAM(severity) 442#endif 443 444#define PLOG(severity) \ 445 LAZY_STREAM(PLOG_STREAM(severity), LOG_IS_ON(severity)) 446 447#define PLOG_IF(severity, condition) \ 448 LAZY_STREAM(PLOG_STREAM(severity), LOG_IS_ON(severity) && (condition)) 449 450// http://crbug.com/16512 is open for a real fix for this. For now, Windows 451// uses OFFICIAL_BUILD and other platforms use the branding flag when NDEBUG is 452// defined. 453#if ( defined(OS_WIN) && defined(OFFICIAL_BUILD)) || \ 454 (!defined(OS_WIN) && defined(NDEBUG) && defined(GOOGLE_CHROME_BUILD)) 455#define LOGGING_IS_OFFICIAL_BUILD 1 456#else 457#define LOGGING_IS_OFFICIAL_BUILD 0 458#endif 459 460// The actual stream used isn't important. 461#define EAT_STREAM_PARAMETERS \ 462 true ? (void) 0 : ::logging::LogMessageVoidify() & LOG_STREAM(FATAL) 463 464// CHECK dies with a fatal error if condition is not true. It is *not* 465// controlled by NDEBUG, so the check will be executed regardless of 466// compilation mode. 467// 468// We make sure CHECK et al. always evaluates their arguments, as 469// doing CHECK(FunctionWithSideEffect()) is a common idiom. 470 471#if LOGGING_IS_OFFICIAL_BUILD 472 473// Make all CHECK functions discard their log strings to reduce code 474// bloat for official builds. 475 476// TODO(akalin): This would be more valuable if there were some way to 477// remove BreakDebugger() from the backtrace, perhaps by turning it 478// into a macro (like __debugbreak() on Windows). 479#define CHECK(condition) \ 480 !(condition) ? ::base::debug::BreakDebugger() : EAT_STREAM_PARAMETERS 481 482#define PCHECK(condition) CHECK(condition) 483 484#define CHECK_OP(name, op, val1, val2) CHECK((val1) op (val2)) 485 486#else 487 488#define CHECK(condition) \ 489 LAZY_STREAM(LOG_STREAM(FATAL), !(condition)) \ 490 << "Check failed: " #condition ". " 491 492#define PCHECK(condition) \ 493 LAZY_STREAM(PLOG_STREAM(FATAL), !(condition)) \ 494 << "Check failed: " #condition ". " 495 496// Helper macro for binary operators. 497// Don't use this macro directly in your code, use CHECK_EQ et al below. 498// 499// TODO(akalin): Rewrite this so that constructs like if (...) 500// CHECK_EQ(...) else { ... } work properly. 501#define CHECK_OP(name, op, val1, val2) \ 502 if (std::string* _result = \ 503 logging::Check##name##Impl((val1), (val2), \ 504 #val1 " " #op " " #val2)) \ 505 logging::LogMessage(__FILE__, __LINE__, _result).stream() 506 507#endif 508 509// Build the error message string. This is separate from the "Impl" 510// function template because it is not performance critical and so can 511// be out of line, while the "Impl" code should be inline. Caller 512// takes ownership of the returned string. 513template<class t1, class t2> 514std::string* MakeCheckOpString(const t1& v1, const t2& v2, const char* names) { 515 std::ostringstream ss; 516 ss << names << " (" << v1 << " vs. " << v2 << ")"; 517 std::string* msg = new std::string(ss.str()); 518 return msg; 519} 520 521// MSVC doesn't like complex extern templates and DLLs. 522#if !defined(COMPILER_MSVC) 523// Commonly used instantiations of MakeCheckOpString<>. Explicitly instantiated 524// in logging.cc. 525extern template BASE_EXPORT std::string* MakeCheckOpString<int, int>( 526 const int&, const int&, const char* names); 527extern template BASE_EXPORT 528std::string* MakeCheckOpString<unsigned long, unsigned long>( 529 const unsigned long&, const unsigned long&, const char* names); 530extern template BASE_EXPORT 531std::string* MakeCheckOpString<unsigned long, unsigned int>( 532 const unsigned long&, const unsigned int&, const char* names); 533extern template BASE_EXPORT 534std::string* MakeCheckOpString<unsigned int, unsigned long>( 535 const unsigned int&, const unsigned long&, const char* names); 536extern template BASE_EXPORT 537std::string* MakeCheckOpString<std::string, std::string>( 538 const std::string&, const std::string&, const char* name); 539#endif 540 541// Helper functions for CHECK_OP macro. 542// The (int, int) specialization works around the issue that the compiler 543// will not instantiate the template version of the function on values of 544// unnamed enum type - see comment below. 545#define DEFINE_CHECK_OP_IMPL(name, op) \ 546 template <class t1, class t2> \ 547 inline std::string* Check##name##Impl(const t1& v1, const t2& v2, \ 548 const char* names) { \ 549 if (v1 op v2) return NULL; \ 550 else return MakeCheckOpString(v1, v2, names); \ 551 } \ 552 inline std::string* Check##name##Impl(int v1, int v2, const char* names) { \ 553 if (v1 op v2) return NULL; \ 554 else return MakeCheckOpString(v1, v2, names); \ 555 } 556DEFINE_CHECK_OP_IMPL(EQ, ==) 557DEFINE_CHECK_OP_IMPL(NE, !=) 558DEFINE_CHECK_OP_IMPL(LE, <=) 559DEFINE_CHECK_OP_IMPL(LT, < ) 560DEFINE_CHECK_OP_IMPL(GE, >=) 561DEFINE_CHECK_OP_IMPL(GT, > ) 562#undef DEFINE_CHECK_OP_IMPL 563 564#define CHECK_EQ(val1, val2) CHECK_OP(EQ, ==, val1, val2) 565#define CHECK_NE(val1, val2) CHECK_OP(NE, !=, val1, val2) 566#define CHECK_LE(val1, val2) CHECK_OP(LE, <=, val1, val2) 567#define CHECK_LT(val1, val2) CHECK_OP(LT, < , val1, val2) 568#define CHECK_GE(val1, val2) CHECK_OP(GE, >=, val1, val2) 569#define CHECK_GT(val1, val2) CHECK_OP(GT, > , val1, val2) 570 571#if LOGGING_IS_OFFICIAL_BUILD 572// In order to have optimized code for official builds, remove DLOGs and 573// DCHECKs. 574#define ENABLE_DLOG 0 575#define ENABLE_DCHECK 0 576 577#elif defined(NDEBUG) 578// Otherwise, if we're a release build, remove DLOGs but not DCHECKs 579// (since those can still be turned on via a command-line flag). 580#define ENABLE_DLOG 0 581#define ENABLE_DCHECK 1 582 583#else 584// Otherwise, we're a debug build so enable DLOGs and DCHECKs. 585#define ENABLE_DLOG 1 586#define ENABLE_DCHECK 1 587#endif 588 589// Definitions for DLOG et al. 590 591#if ENABLE_DLOG 592 593#define DLOG_IS_ON(severity) LOG_IS_ON(severity) 594#define DLOG_IF(severity, condition) LOG_IF(severity, condition) 595#define DLOG_ASSERT(condition) LOG_ASSERT(condition) 596#define DPLOG_IF(severity, condition) PLOG_IF(severity, condition) 597#define DVLOG_IF(verboselevel, condition) VLOG_IF(verboselevel, condition) 598#define DVPLOG_IF(verboselevel, condition) VPLOG_IF(verboselevel, condition) 599 600#else // ENABLE_DLOG 601 602// If ENABLE_DLOG is off, we want to avoid emitting any references to 603// |condition| (which may reference a variable defined only if NDEBUG 604// is not defined). Contrast this with DCHECK et al., which has 605// different behavior. 606 607#define DLOG_IS_ON(severity) false 608#define DLOG_IF(severity, condition) EAT_STREAM_PARAMETERS 609#define DLOG_ASSERT(condition) EAT_STREAM_PARAMETERS 610#define DPLOG_IF(severity, condition) EAT_STREAM_PARAMETERS 611#define DVLOG_IF(verboselevel, condition) EAT_STREAM_PARAMETERS 612#define DVPLOG_IF(verboselevel, condition) EAT_STREAM_PARAMETERS 613 614#endif // ENABLE_DLOG 615 616// DEBUG_MODE is for uses like 617// if (DEBUG_MODE) foo.CheckThatFoo(); 618// instead of 619// #ifndef NDEBUG 620// foo.CheckThatFoo(); 621// #endif 622// 623// We tie its state to ENABLE_DLOG. 624enum { DEBUG_MODE = ENABLE_DLOG }; 625 626#undef ENABLE_DLOG 627 628#define DLOG(severity) \ 629 LAZY_STREAM(LOG_STREAM(severity), DLOG_IS_ON(severity)) 630 631#if defined(OS_WIN) 632#define DLOG_GETLASTERROR(severity) \ 633 LAZY_STREAM(LOG_GETLASTERROR_STREAM(severity), DLOG_IS_ON(severity)) 634#define DLOG_GETLASTERROR_MODULE(severity, module) \ 635 LAZY_STREAM(LOG_GETLASTERROR_STREAM(severity, module), \ 636 DLOG_IS_ON(severity)) 637#elif defined(OS_POSIX) 638#define DLOG_ERRNO(severity) \ 639 LAZY_STREAM(LOG_ERRNO_STREAM(severity), DLOG_IS_ON(severity)) 640#endif 641 642#define DPLOG(severity) \ 643 LAZY_STREAM(PLOG_STREAM(severity), DLOG_IS_ON(severity)) 644 645#define DVLOG(verboselevel) DVLOG_IF(verboselevel, VLOG_IS_ON(verboselevel)) 646 647#define DVPLOG(verboselevel) DVPLOG_IF(verboselevel, VLOG_IS_ON(verboselevel)) 648 649// Definitions for DCHECK et al. 650 651#if ENABLE_DCHECK 652 653#if defined(NDEBUG) 654 655BASE_EXPORT extern DcheckState g_dcheck_state; 656 657#if defined(DCHECK_ALWAYS_ON) 658 659#define DCHECK_IS_ON() true 660#define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \ 661 COMPACT_GOOGLE_LOG_EX_FATAL(ClassName , ##__VA_ARGS__) 662#define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_FATAL 663const LogSeverity LOG_DCHECK = LOG_FATAL; 664 665#else 666 667#define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \ 668 COMPACT_GOOGLE_LOG_EX_ERROR_REPORT(ClassName , ##__VA_ARGS__) 669#define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_ERROR_REPORT 670const LogSeverity LOG_DCHECK = LOG_ERROR_REPORT; 671#define DCHECK_IS_ON() \ 672 ((::logging::g_dcheck_state == \ 673 ::logging::ENABLE_DCHECK_FOR_NON_OFFICIAL_RELEASE_BUILDS) && \ 674 LOG_IS_ON(DCHECK)) 675 676#endif // defined(DCHECK_ALWAYS_ON) 677 678#else // defined(NDEBUG) 679 680// On a regular debug build, we want to have DCHECKs enabled. 681#define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \ 682 COMPACT_GOOGLE_LOG_EX_FATAL(ClassName , ##__VA_ARGS__) 683#define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_FATAL 684const LogSeverity LOG_DCHECK = LOG_FATAL; 685#define DCHECK_IS_ON() true 686 687#endif // defined(NDEBUG) 688 689#else // ENABLE_DCHECK 690 691// These are just dummy values since DCHECK_IS_ON() is always false in 692// this case. 693#define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \ 694 COMPACT_GOOGLE_LOG_EX_INFO(ClassName , ##__VA_ARGS__) 695#define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_INFO 696const LogSeverity LOG_DCHECK = LOG_INFO; 697#define DCHECK_IS_ON() false 698 699#endif // ENABLE_DCHECK 700#undef ENABLE_DCHECK 701 702// DCHECK et al. make sure to reference |condition| regardless of 703// whether DCHECKs are enabled; this is so that we don't get unused 704// variable warnings if the only use of a variable is in a DCHECK. 705// This behavior is different from DLOG_IF et al. 706 707#define DCHECK(condition) \ 708 LAZY_STREAM(LOG_STREAM(DCHECK), DCHECK_IS_ON() && !(condition)) \ 709 << "Check failed: " #condition ". " 710 711#define DPCHECK(condition) \ 712 LAZY_STREAM(PLOG_STREAM(DCHECK), DCHECK_IS_ON() && !(condition)) \ 713 << "Check failed: " #condition ". " 714 715// Helper macro for binary operators. 716// Don't use this macro directly in your code, use DCHECK_EQ et al below. 717#define DCHECK_OP(name, op, val1, val2) \ 718 if (DCHECK_IS_ON()) \ 719 if (std::string* _result = \ 720 logging::Check##name##Impl((val1), (val2), \ 721 #val1 " " #op " " #val2)) \ 722 logging::LogMessage( \ 723 __FILE__, __LINE__, ::logging::LOG_DCHECK, \ 724 _result).stream() 725 726// Equality/Inequality checks - compare two values, and log a 727// LOG_DCHECK message including the two values when the result is not 728// as expected. The values must have operator<<(ostream, ...) 729// defined. 730// 731// You may append to the error message like so: 732// DCHECK_NE(1, 2) << ": The world must be ending!"; 733// 734// We are very careful to ensure that each argument is evaluated exactly 735// once, and that anything which is legal to pass as a function argument is 736// legal here. In particular, the arguments may be temporary expressions 737// which will end up being destroyed at the end of the apparent statement, 738// for example: 739// DCHECK_EQ(string("abc")[1], 'b'); 740// 741// WARNING: These may not compile correctly if one of the arguments is a pointer 742// and the other is NULL. To work around this, simply static_cast NULL to the 743// type of the desired pointer. 744 745#define DCHECK_EQ(val1, val2) DCHECK_OP(EQ, ==, val1, val2) 746#define DCHECK_NE(val1, val2) DCHECK_OP(NE, !=, val1, val2) 747#define DCHECK_LE(val1, val2) DCHECK_OP(LE, <=, val1, val2) 748#define DCHECK_LT(val1, val2) DCHECK_OP(LT, < , val1, val2) 749#define DCHECK_GE(val1, val2) DCHECK_OP(GE, >=, val1, val2) 750#define DCHECK_GT(val1, val2) DCHECK_OP(GT, > , val1, val2) 751 752#define NOTREACHED() DCHECK(false) 753 754// Redefine the standard assert to use our nice log files 755#undef assert 756#define assert(x) DLOG_ASSERT(x) 757 758// This class more or less represents a particular log message. You 759// create an instance of LogMessage and then stream stuff to it. 760// When you finish streaming to it, ~LogMessage is called and the 761// full message gets streamed to the appropriate destination. 762// 763// You shouldn't actually use LogMessage's constructor to log things, 764// though. You should use the LOG() macro (and variants thereof) 765// above. 766class BASE_EXPORT LogMessage { 767 public: 768 LogMessage(const char* file, int line, LogSeverity severity, int ctr); 769 770 // Two special constructors that generate reduced amounts of code at 771 // LOG call sites for common cases. 772 // 773 // Used for LOG(INFO): Implied are: 774 // severity = LOG_INFO, ctr = 0 775 // 776 // Using this constructor instead of the more complex constructor above 777 // saves a couple of bytes per call site. 778 LogMessage(const char* file, int line); 779 780 // Used for LOG(severity) where severity != INFO. Implied 781 // are: ctr = 0 782 // 783 // Using this constructor instead of the more complex constructor above 784 // saves a couple of bytes per call site. 785 LogMessage(const char* file, int line, LogSeverity severity); 786 787 // A special constructor used for check failures. Takes ownership 788 // of the given string. 789 // Implied severity = LOG_FATAL 790 LogMessage(const char* file, int line, std::string* result); 791 792 // A special constructor used for check failures, with the option to 793 // specify severity. Takes ownership of the given string. 794 LogMessage(const char* file, int line, LogSeverity severity, 795 std::string* result); 796 797 ~LogMessage(); 798 799 std::ostream& stream() { return stream_; } 800 801 private: 802 void Init(const char* file, int line); 803 804 LogSeverity severity_; 805 std::ostringstream stream_; 806 size_t message_start_; // Offset of the start of the message (past prefix 807 // info). 808 // The file and line information passed in to the constructor. 809 const char* file_; 810 const int line_; 811 812#if defined(OS_WIN) 813 // Stores the current value of GetLastError in the constructor and restores 814 // it in the destructor by calling SetLastError. 815 // This is useful since the LogMessage class uses a lot of Win32 calls 816 // that will lose the value of GLE and the code that called the log function 817 // will have lost the thread error value when the log call returns. 818 class SaveLastError { 819 public: 820 SaveLastError(); 821 ~SaveLastError(); 822 823 unsigned long get_error() const { return last_error_; } 824 825 protected: 826 unsigned long last_error_; 827 }; 828 829 SaveLastError last_error_; 830#endif 831 832 DISALLOW_COPY_AND_ASSIGN(LogMessage); 833}; 834 835// A non-macro interface to the log facility; (useful 836// when the logging level is not a compile-time constant). 837inline void LogAtLevel(int const log_level, std::string const &msg) { 838 LogMessage(__FILE__, __LINE__, log_level).stream() << msg; 839} 840 841// This class is used to explicitly ignore values in the conditional 842// logging macros. This avoids compiler warnings like "value computed 843// is not used" and "statement has no effect". 844class LogMessageVoidify { 845 public: 846 LogMessageVoidify() { } 847 // This has to be an operator with a precedence lower than << but 848 // higher than ?: 849 void operator&(std::ostream&) { } 850}; 851 852#if defined(OS_WIN) 853typedef unsigned long SystemErrorCode; 854#elif defined(OS_POSIX) 855typedef int SystemErrorCode; 856#endif 857 858// Alias for ::GetLastError() on Windows and errno on POSIX. Avoids having to 859// pull in windows.h just for GetLastError() and DWORD. 860BASE_EXPORT SystemErrorCode GetLastSystemErrorCode(); 861 862#if defined(OS_WIN) 863// Appends a formatted system message of the GetLastError() type. 864class BASE_EXPORT Win32ErrorLogMessage { 865 public: 866 Win32ErrorLogMessage(const char* file, 867 int line, 868 LogSeverity severity, 869 SystemErrorCode err, 870 const char* module); 871 872 Win32ErrorLogMessage(const char* file, 873 int line, 874 LogSeverity severity, 875 SystemErrorCode err); 876 877 // Appends the error message before destructing the encapsulated class. 878 ~Win32ErrorLogMessage(); 879 880 std::ostream& stream() { return log_message_.stream(); } 881 882 private: 883 SystemErrorCode err_; 884 // Optional name of the module defining the error. 885 const char* module_; 886 LogMessage log_message_; 887 888 DISALLOW_COPY_AND_ASSIGN(Win32ErrorLogMessage); 889}; 890#elif defined(OS_POSIX) 891// Appends a formatted system message of the errno type 892class BASE_EXPORT ErrnoLogMessage { 893 public: 894 ErrnoLogMessage(const char* file, 895 int line, 896 LogSeverity severity, 897 SystemErrorCode err); 898 899 // Appends the error message before destructing the encapsulated class. 900 ~ErrnoLogMessage(); 901 902 std::ostream& stream() { return log_message_.stream(); } 903 904 private: 905 SystemErrorCode err_; 906 LogMessage log_message_; 907 908 DISALLOW_COPY_AND_ASSIGN(ErrnoLogMessage); 909}; 910#endif // OS_WIN 911 912// Closes the log file explicitly if open. 913// NOTE: Since the log file is opened as necessary by the action of logging 914// statements, there's no guarantee that it will stay closed 915// after this call. 916BASE_EXPORT void CloseLogFile(); 917 918// Async signal safe logging mechanism. 919BASE_EXPORT void RawLog(int level, const char* message); 920 921#define RAW_LOG(level, message) logging::RawLog(logging::LOG_ ## level, message) 922 923#define RAW_CHECK(condition) \ 924 do { \ 925 if (!(condition)) \ 926 logging::RawLog(logging::LOG_FATAL, "Check failed: " #condition "\n"); \ 927 } while (0) 928 929#if defined(OS_WIN) 930// Returns the default log file path. 931BASE_EXPORT std::wstring GetLogFileFullPath(); 932#endif 933 934} // namespace logging 935 936// These functions are provided as a convenience for logging, which is where we 937// use streams (it is against Google style to use streams in other places). It 938// is designed to allow you to emit non-ASCII Unicode strings to the log file, 939// which is normally ASCII. It is relatively slow, so try not to use it for 940// common cases. Non-ASCII characters will be converted to UTF-8 by these 941// operators. 942BASE_EXPORT std::ostream& operator<<(std::ostream& out, const wchar_t* wstr); 943inline std::ostream& operator<<(std::ostream& out, const std::wstring& wstr) { 944 return out << wstr.c_str(); 945} 946 947// The NOTIMPLEMENTED() macro annotates codepaths which have 948// not been implemented yet. 949// 950// The implementation of this macro is controlled by NOTIMPLEMENTED_POLICY: 951// 0 -- Do nothing (stripped by compiler) 952// 1 -- Warn at compile time 953// 2 -- Fail at compile time 954// 3 -- Fail at runtime (DCHECK) 955// 4 -- [default] LOG(ERROR) at runtime 956// 5 -- LOG(ERROR) at runtime, only once per call-site 957 958#ifndef NOTIMPLEMENTED_POLICY 959#if defined(OS_ANDROID) && defined(OFFICIAL_BUILD) 960#define NOTIMPLEMENTED_POLICY 0 961#else 962// Select default policy: LOG(ERROR) 963#define NOTIMPLEMENTED_POLICY 4 964#endif 965#endif 966 967#if defined(COMPILER_GCC) 968// On Linux, with GCC, we can use __PRETTY_FUNCTION__ to get the demangled name 969// of the current function in the NOTIMPLEMENTED message. 970#define NOTIMPLEMENTED_MSG "Not implemented reached in " << __PRETTY_FUNCTION__ 971#else 972#define NOTIMPLEMENTED_MSG "NOT IMPLEMENTED" 973#endif 974 975#if NOTIMPLEMENTED_POLICY == 0 976#define NOTIMPLEMENTED() EAT_STREAM_PARAMETERS 977#elif NOTIMPLEMENTED_POLICY == 1 978// TODO, figure out how to generate a warning 979#define NOTIMPLEMENTED() COMPILE_ASSERT(false, NOT_IMPLEMENTED) 980#elif NOTIMPLEMENTED_POLICY == 2 981#define NOTIMPLEMENTED() COMPILE_ASSERT(false, NOT_IMPLEMENTED) 982#elif NOTIMPLEMENTED_POLICY == 3 983#define NOTIMPLEMENTED() NOTREACHED() 984#elif NOTIMPLEMENTED_POLICY == 4 985#define NOTIMPLEMENTED() LOG(ERROR) << NOTIMPLEMENTED_MSG 986#elif NOTIMPLEMENTED_POLICY == 5 987#define NOTIMPLEMENTED() do {\ 988 static bool logged_once = false;\ 989 LOG_IF(ERROR, !logged_once) << NOTIMPLEMENTED_MSG;\ 990 logged_once = true;\ 991} while(0);\ 992EAT_STREAM_PARAMETERS 993#endif 994 995#endif // BASE_LOGGING_H_ 996