1 // Copyright 2012 The Chromium Authors 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 PARTITION_ALLOC_PARTITION_ALLOC_BASE_LOGGING_H_ 6 #define PARTITION_ALLOC_PARTITION_ALLOC_BASE_LOGGING_H_ 7 8 #include <cassert> 9 #include <cstddef> 10 #include <cstdint> 11 12 #include "build/build_config.h" 13 #include "partition_alloc/partition_alloc_base/compiler_specific.h" 14 #include "partition_alloc/partition_alloc_base/component_export.h" 15 #include "partition_alloc/partition_alloc_base/debug/debugging_buildflags.h" 16 #include "partition_alloc/partition_alloc_base/log_message.h" 17 18 // TODO(1151236): Need to update the description, because logging for PA 19 // standalone library was minimized. 20 // 21 // Optional message capabilities 22 // ----------------------------- 23 // Assertion failed messages and fatal errors are displayed in a dialog box 24 // before the application exits. However, running this UI creates a message 25 // loop, which causes application messages to be processed and potentially 26 // dispatched to existing application windows. Since the application is in a 27 // bad state when this assertion dialog is displayed, these messages may not 28 // get processed and hang the dialog, or the application might go crazy. 29 // 30 // Therefore, it can be beneficial to display the error dialog in a separate 31 // process from the main application. When the logging system needs to display 32 // a fatal error dialog box, it will look for a program called 33 // "DebugMessage.exe" in the same directory as the application executable. It 34 // will run this application with the message as the command line, and will 35 // not include the name of the application as is traditional for easier 36 // parsing. 37 // 38 // The code for DebugMessage.exe is only one line. In WinMain, do: 39 // MessageBox(NULL, GetCommandLineW(), L"Fatal Error", 0); 40 // 41 // If DebugMessage.exe is not found, the logging code will use a normal 42 // MessageBox, potentially causing the problems discussed above. 43 44 // Instructions 45 // ------------ 46 // 47 // Make a bunch of macros for logging. The way to log things is to stream 48 // things to PA_LOG(<a particular severity level>). E.g., 49 // 50 // PA_LOG(INFO) << "Found " << num_cookies << " cookies"; 51 // 52 // You can also do conditional logging: 53 // 54 // PA_LOG_IF(INFO, num_cookies > 10) << "Got lots of cookies"; 55 // 56 // The CHECK(condition) macro is active in both debug and release builds and 57 // effectively performs a PA_LOG(FATAL) which terminates the process and 58 // generates a crashdump unless a debugger is attached. 59 // 60 // There are also "debug mode" logging macros like the ones above: 61 // 62 // PA_DLOG(INFO) << "Found cookies"; 63 // 64 // PA_DLOG_IF(INFO, num_cookies > 10) << "Got lots of cookies"; 65 // 66 // All "debug mode" logging is compiled away to nothing for non-debug mode 67 // compiles. PA_LOG_IF and development flags also work well together 68 // because the code can be compiled away sometimes. 69 // 70 // We also have 71 // 72 // PA_LOG_ASSERT(assertion); 73 // PA_DLOG_ASSERT(assertion); 74 // 75 // which is syntactic sugar for PA_{,D}LOG_IF(FATAL, assert fails) << assertion; 76 // 77 // There are "verbose level" logging macros. They look like 78 // 79 // PA_VLOG(1) << "I'm printed when you run the program with --v=1 or more"; 80 // PA_VLOG(2) << "I'm printed when you run the program with --v=2 or more"; 81 // 82 // These always log at the INFO log level (when they log at all). 83 // 84 // There's also PA_VLOG_IS_ON(n) "verbose level" condition macro. To be used as 85 // 86 // if (PA_VLOG_IS_ON(2)) { 87 // // do some logging preparation and logging 88 // // that can't be accomplished with just PA_VLOG(2) << ...; 89 // } 90 // 91 // There is also a PA_VLOG_IF "verbose level" condition macro for sample 92 // cases, when some extra computation and preparation for logs is not 93 // needed. 94 // 95 // PA_VLOG_IF(1, (size > 1024)) 96 // << "I'm printed when size is more than 1024 and when you run the " 97 // "program with --v=1 or more"; 98 // 99 // We also override the standard 'assert' to use 'PA_DLOG_ASSERT'. 100 // 101 // Lastly, there is: 102 // 103 // PA_PLOG(ERROR) << "Couldn't do foo"; 104 // PA_DPLOG(ERROR) << "Couldn't do foo"; 105 // PA_PLOG_IF(ERROR, cond) << "Couldn't do foo"; 106 // PA_DPLOG_IF(ERROR, cond) << "Couldn't do foo"; 107 // PA_PCHECK(condition) << "Couldn't do foo"; 108 // PA_DPCHECK(condition) << "Couldn't do foo"; 109 // 110 // which append the last system error to the message in string form (taken from 111 // GetLastError() on Windows and errno on POSIX). 112 // 113 // The supported severity levels for macros that allow you to specify one 114 // are (in increasing order of severity) INFO, WARNING, ERROR, and FATAL. 115 // 116 // Very important: logging a message at the FATAL severity level causes 117 // the program to terminate (after the message is logged). 118 // 119 // There is the special severity of DFATAL, which logs FATAL in DCHECK-enabled 120 // builds, ERROR in normal mode. 121 // 122 // Output is formatted as per the following example: 123 // [VERBOSE1:drm_device_handle.cc(90)] Succeeded 124 // authenticating /dev/dri/card0 in 0 ms with 1 attempt(s) 125 // 126 // The colon separated fields inside the brackets are as follows: 127 // 1. The log level 128 // 2. The filename and line number where the log was instantiated 129 // 130 // Additional logging-related information can be found here: 131 // https://chromium.googlesource.com/chromium/src/+/main/docs/linux/debugging.md#Logging 132 133 namespace partition_alloc::internal::logging { 134 135 // Sets the log level. Anything at or above this level will be written to the 136 // log file/displayed to the user (if applicable). Anything below this level 137 // will be silently ignored. The log level defaults to 0 (everything is logged 138 // up to level INFO) if this function is not called. 139 // Note that log messages for VLOG(x) are logged at level -x, so setting 140 // the min log level to negative values enables verbose logging. 141 PA_COMPONENT_EXPORT(PARTITION_ALLOC_BASE) void SetMinLogLevel(int level); 142 143 // Gets the current log level. 144 PA_COMPONENT_EXPORT(PARTITION_ALLOC_BASE) int GetMinLogLevel(); 145 146 // Used by PA_LOG_IS_ON to lazy-evaluate stream arguments. 147 PA_COMPONENT_EXPORT(PARTITION_ALLOC_BASE) 148 bool ShouldCreateLogMessage(int severity); 149 150 // Gets the PA_VLOG default verbosity level. 151 PA_COMPONENT_EXPORT(PARTITION_ALLOC_BASE) int GetVlogVerbosity(); 152 153 // A few definitions of macros that don't generate much code. These are used 154 // by PA_LOG() and LOG_IF, etc. Since these are used all over our code, it's 155 // better to have compact code for these operations. 156 #define PA_COMPACT_GOOGLE_LOG_EX_INFO(ClassName) \ 157 ::partition_alloc::internal::logging::ClassName( \ 158 __FILE__, __LINE__, ::partition_alloc::internal::logging::LOGGING_INFO) 159 #define PA_COMPACT_GOOGLE_PLOG_EX_INFO(ClassName, error_code) \ 160 ::partition_alloc::internal::logging::ClassName( \ 161 __FILE__, __LINE__, ::partition_alloc::internal::logging::LOGGING_INFO, \ 162 error_code) 163 #define PA_COMPACT_GOOGLE_LOG_EX_WARNING(ClassName) \ 164 ::partition_alloc::internal::logging::ClassName( \ 165 __FILE__, __LINE__, \ 166 ::partition_alloc::internal::logging::LOGGING_WARNING) 167 #define PA_COMPACT_GOOGLE_PLOG_EX_WARNING(ClassName, error_code) \ 168 ::partition_alloc::internal::logging::ClassName( \ 169 __FILE__, __LINE__, \ 170 ::partition_alloc::internal::logging::LOGGING_WARNING) 171 #define PA_COMPACT_GOOGLE_LOG_EX_ERROR(ClassName) \ 172 ::partition_alloc::internal::logging::ClassName( \ 173 __FILE__, __LINE__, ::partition_alloc::internal::logging::LOGGING_ERROR) 174 #define PA_COMPACT_GOOGLE_PLOG_EX_ERROR(ClassName, error_code) \ 175 ::partition_alloc::internal::logging::ClassName( \ 176 __FILE__, __LINE__, ::partition_alloc::internal::logging::LOGGING_ERROR, \ 177 error_code) 178 #define PA_COMPACT_GOOGLE_LOG_EX_FATAL(ClassName) \ 179 ::partition_alloc::internal::logging::ClassName( \ 180 __FILE__, __LINE__, ::partition_alloc::internal::logging::LOGGING_FATAL) 181 #define PA_COMPACT_GOOGLE_PLOG_EX_FATAL(ClassName, error_code) \ 182 ::partition_alloc::internal::logging::ClassName( \ 183 __FILE__, __LINE__, ::partition_alloc::internal::logging::LOGGING_FATAL, \ 184 error_code) 185 #define PA_COMPACT_GOOGLE_LOG_EX_DFATAL(ClassName) \ 186 ::partition_alloc::internal::logging::ClassName( \ 187 __FILE__, __LINE__, \ 188 ::partition_alloc::internal::logging::LOGGING_DFATAL) 189 #define PA_COMPACT_GOOGLE_PLOG_EX_DFATAL(ClassName, error_code) \ 190 ::partition_alloc::internal::logging::ClassName( \ 191 __FILE__, __LINE__, \ 192 ::partition_alloc::internal::logging::LOGGING_DFATAL, error_code) 193 #define PA_COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName) \ 194 ::partition_alloc::internal::logging::ClassName( \ 195 __FILE__, __LINE__, \ 196 ::partition_alloc::internal::logging::LOGGING_DCHECK) 197 #define PA_COMPACT_GOOGLE_PLOG_EX_DCHECK(ClassName, error_code) \ 198 ::partition_alloc::internal::logging::ClassName( \ 199 __FILE__, __LINE__, \ 200 ::partition_alloc::internal::logging::LOGGING_DCHECK, error_code) 201 202 #define PA_COMPACT_GOOGLE_LOG_INFO PA_COMPACT_GOOGLE_LOG_EX_INFO(LogMessage) 203 #define PA_COMPACT_GOOGLE_LOG_WARNING \ 204 PA_COMPACT_GOOGLE_LOG_EX_WARNING(LogMessage) 205 #define PA_COMPACT_GOOGLE_LOG_ERROR PA_COMPACT_GOOGLE_LOG_EX_ERROR(LogMessage) 206 #define PA_COMPACT_GOOGLE_LOG_FATAL PA_COMPACT_GOOGLE_LOG_EX_FATAL(LogMessage) 207 #define PA_COMPACT_GOOGLE_LOG_DFATAL PA_COMPACT_GOOGLE_LOG_EX_DFATAL(LogMessage) 208 #define PA_COMPACT_GOOGLE_LOG_DCHECK PA_COMPACT_GOOGLE_LOG_EX_DCHECK(LogMessage) 209 210 #if BUILDFLAG(IS_WIN) 211 // wingdi.h defines ERROR to be 0. When we call PA_LOG(ERROR), it gets 212 // substituted with 0, and it expands to PA_COMPACT_GOOGLE_LOG_0. To allow us 213 // to keep using this syntax, we define this macro to do the same thing 214 // as PA_COMPACT_GOOGLE_LOG_ERROR, and also define ERROR the same way that 215 // the Windows SDK does for consistency. 216 #define PA_ERROR 0 217 #define PA_COMPACT_GOOGLE_LOG_EX_0(ClassName) \ 218 PA_COMPACT_GOOGLE_LOG_EX_ERROR(ClassName) 219 #define PA_COMPACT_GOOGLE_LOG_0 PA_COMPACT_GOOGLE_LOG_ERROR 220 // Needed for LOG_IS_ON(ERROR). 221 constexpr LogSeverity LOGGING_0 = LOGGING_ERROR; 222 #endif 223 224 // As special cases, we can assume that LOG_IS_ON(FATAL) always holds. Also, 225 // LOG_IS_ON(DFATAL) always holds in debug mode. In particular, CHECK()s will 226 // always fire if they fail. 227 #define PA_LOG_IS_ON(severity) \ 228 (::partition_alloc::internal::logging::ShouldCreateLogMessage( \ 229 ::partition_alloc::internal::logging::LOGGING_##severity)) 230 231 // We don't do any caching tricks with VLOG_IS_ON() like the 232 // google-glog version since it increases binary size. This means 233 // that using the v-logging functions in conjunction with --vmodule 234 // may be slow. 235 #define PA_VLOG_IS_ON(verboselevel) \ 236 ((verboselevel) <= ::partition_alloc::internal::logging::GetVlogVerbosity()) 237 238 // Helper macro which avoids evaluating the arguments to a stream if 239 // the condition doesn't hold. Condition is evaluated once and only once. 240 #define PA_LAZY_STREAM(stream, condition) \ 241 !(condition) \ 242 ? (void)0 \ 243 : ::partition_alloc::internal::logging::LogMessageVoidify() & (stream) 244 245 // We use the preprocessor's merging operator, "##", so that, e.g., 246 // PA_LOG(INFO) becomes the token PA_COMPACT_GOOGLE_LOG_INFO. There's some 247 // funny subtle difference between ostream member streaming functions (e.g., 248 // ostream::operator<<(int) and ostream non-member streaming functions 249 // (e.g., ::operator<<(ostream&, string&): it turns out that it's 250 // impossible to stream something like a string directly to an unnamed 251 // ostream. We employ a neat hack by calling the stream() member 252 // function of LogMessage which seems to avoid the problem. 253 #define PA_LOG_STREAM(severity) PA_COMPACT_GOOGLE_LOG_##severity.stream() 254 255 #define PA_LOG(severity) \ 256 PA_LAZY_STREAM(PA_LOG_STREAM(severity), PA_LOG_IS_ON(severity)) 257 #define PA_LOG_IF(severity, condition) \ 258 PA_LAZY_STREAM(PA_LOG_STREAM(severity), PA_LOG_IS_ON(severity) && (condition)) 259 260 // The VLOG macros log with negative verbosities. 261 #define PA_VLOG_STREAM(verbose_level) \ 262 ::partition_alloc::internal::logging::LogMessage(__FILE__, __LINE__, \ 263 -(verbose_level)) \ 264 .stream() 265 266 #define PA_VLOG(verbose_level) \ 267 PA_LAZY_STREAM(PA_VLOG_STREAM(verbose_level), PA_VLOG_IS_ON(verbose_level)) 268 269 #define PA_VLOG_IF(verbose_level, condition) \ 270 PA_LAZY_STREAM(PA_VLOG_STREAM(verbose_level), \ 271 PA_VLOG_IS_ON(verbose_level) && (condition)) 272 273 #if BUILDFLAG(IS_WIN) 274 #define PA_VPLOG_STREAM(verbose_level) \ 275 ::partition_alloc::internal::logging::Win32ErrorLogMessage( \ 276 __FILE__, __LINE__, -(verbose_level), \ 277 ::partition_alloc::internal::logging::GetLastSystemErrorCode()) \ 278 .stream() 279 #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) 280 #define PA_VPLOG_STREAM(verbose_level) \ 281 ::partition_alloc::internal::logging::ErrnoLogMessage( \ 282 __FILE__, __LINE__, -(verbose_level), \ 283 ::partition_alloc::internal::logging::GetLastSystemErrorCode()) \ 284 .stream() 285 #endif 286 287 #define PA_VPLOG(verbose_level) \ 288 PA_LAZY_STREAM(PA_VPLOG_STREAM(verbose_level), PA_VLOG_IS_ON(verbose_level)) 289 290 #define PA_VPLOG_IF(verbose_level, condition) \ 291 PA_LAZY_STREAM(PA_VPLOG_STREAM(verbose_level), \ 292 PA_VLOG_IS_ON(verbose_level) && (condition)) 293 294 // TODO(akalin): Add more VLOG variants, e.g. VPLOG. 295 296 #define PA_LOG_ASSERT(condition) \ 297 PA_LOG_IF(FATAL, !(PA_ANALYZER_ASSUME_TRUE(condition))) \ 298 << "Assert failed: " #condition ". " 299 300 #if BUILDFLAG(IS_WIN) 301 #define PA_PLOG_STREAM(severity) \ 302 PA_COMPACT_GOOGLE_PLOG_EX_##severity( \ 303 Win32ErrorLogMessage, \ 304 ::partition_alloc::internal::logging::GetLastSystemErrorCode()) \ 305 .stream() 306 #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) 307 #define PA_PLOG_STREAM(severity) \ 308 PA_COMPACT_GOOGLE_PLOG_EX_##severity( \ 309 ErrnoLogMessage, \ 310 ::partition_alloc::internal::logging::GetLastSystemErrorCode()) \ 311 .stream() 312 #endif 313 314 #define PA_PLOG(severity) \ 315 PA_LAZY_STREAM(PA_PLOG_STREAM(severity), PA_LOG_IS_ON(severity)) 316 317 #define PA_PLOG_IF(severity, condition) \ 318 PA_LAZY_STREAM(PA_PLOG_STREAM(severity), \ 319 PA_LOG_IS_ON(severity) && (condition)) 320 321 // Note that g_swallow_stream is used instead of an arbitrary PA_LOG() stream to 322 // avoid the creation of an object with a non-trivial destructor (LogMessage). 323 // On MSVC x86 (checked on 2015 Update 3), this causes a few additional 324 // pointless instructions to be emitted even at full optimization level, even 325 // though the : arm of the ternary operator is clearly never executed. Using a 326 // simpler object to be &'d with Voidify() avoids these extra instructions. 327 // Using a simpler POD object with a templated operator<< also works to avoid 328 // these instructions. However, this causes warnings on statically defined 329 // implementations of operator<<(std::ostream, ...) in some .cc files, because 330 // they become defined-but-unreferenced functions. A reinterpret_cast of 0 to an 331 // ostream* also is not suitable, because some compilers warn of undefined 332 // behavior. 333 #define PA_EAT_STREAM_PARAMETERS \ 334 true ? (void)0 \ 335 : ::partition_alloc::internal::logging::LogMessageVoidify() & \ 336 (*::partition_alloc::internal::logging::g_swallow_stream) 337 338 // Definitions for DLOG et al. 339 340 #if BUILDFLAG(PA_DCHECK_IS_ON) 341 342 #define PA_DLOG_IS_ON(severity) PA_LOG_IS_ON(severity) 343 #define PA_DLOG_IF(severity, condition) PA_LOG_IF(severity, condition) 344 #define PA_DLOG_ASSERT(condition) PA_LOG_ASSERT(condition) 345 #define PA_DPLOG_IF(severity, condition) PA_PLOG_IF(severity, condition) 346 #define PA_DVLOG_IF(verboselevel, condition) PA_VLOG_IF(verboselevel, condition) 347 #define PA_DVPLOG_IF(verboselevel, condition) \ 348 PA_VPLOG_IF(verboselevel, condition) 349 350 #else // BUILDFLAG(PA_DCHECK_IS_ON) 351 352 // If !BUILDFLAG(PA_DCHECK_IS_ON), we want to avoid emitting any references to 353 // |condition| (which may reference a variable defined only if 354 // BUILDFLAG(PA_DCHECK_IS_ON)). Contrast this with DCHECK et al., which has 355 // different behavior. 356 357 #define PA_DLOG_IS_ON(severity) false 358 #define PA_DLOG_IF(severity, condition) PA_EAT_STREAM_PARAMETERS 359 #define PA_DLOG_ASSERT(condition) PA_EAT_STREAM_PARAMETERS 360 #define PA_DPLOG_IF(severity, condition) PA_EAT_STREAM_PARAMETERS 361 #define PA_DVLOG_IF(verboselevel, condition) PA_EAT_STREAM_PARAMETERS 362 #define PA_DVPLOG_IF(verboselevel, condition) PA_EAT_STREAM_PARAMETERS 363 364 #endif // BUILDFLAG(PA_DCHECK_IS_ON) 365 366 #define PA_DLOG(severity) \ 367 PA_LAZY_STREAM(PA_LOG_STREAM(severity), PA_DLOG_IS_ON(severity)) 368 369 #define PA_DPLOG(severity) \ 370 PA_LAZY_STREAM(PA_PLOG_STREAM(severity), PA_DLOG_IS_ON(severity)) 371 372 #define PA_DVLOG(verboselevel) PA_DVLOG_IF(verboselevel, true) 373 374 #define PA_DVPLOG(verboselevel) PA_DVPLOG_IF(verboselevel, true) 375 376 // Definitions for DCHECK et al. 377 378 #if BUILDFLAG(PA_DCHECK_IS_CONFIGURABLE) 379 PA_COMPONENT_EXPORT(PARTITION_ALLOC_BASE) extern LogSeverity LOGGING_DCHECK; 380 #else 381 constexpr LogSeverity LOGGING_DCHECK = LOGGING_FATAL; 382 #endif // BUILDFLAG(PA_DCHECK_IS_CONFIGURABLE) 383 384 // Redefine the standard assert to use our nice log files 385 #undef assert 386 #define assert(x) PA_DLOG_ASSERT(x) 387 388 // Async signal safe logging mechanism. 389 PA_COMPONENT_EXPORT(PARTITION_ALLOC_BASE) 390 void RawLog(int level, const char* message); 391 392 #define PA_RAW_LOG(level, message) \ 393 ::partition_alloc::internal::logging::RawLog( \ 394 ::partition_alloc::internal::logging::LOGGING_##level, message) 395 396 } // namespace partition_alloc::internal::logging 397 398 #endif // PARTITION_ALLOC_PARTITION_ALLOC_BASE_LOGGING_H_ 399