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 BASE_ALLOCATOR_PARTITION_ALLOCATOR_SRC_PARTITION_ALLOC_PARTITION_ALLOC_BASE_LOGGING_H_ 6 #define BASE_ALLOCATOR_PARTITION_ALLOCATOR_SRC_PARTITION_ALLOC_PARTITION_ALLOC_BASE_LOGGING_H_ 7 8 #include <stddef.h> 9 10 #include <cassert> 11 #include <cstdint> 12 13 #include "build/build_config.h" 14 #include "partition_alloc/partition_alloc_base/compiler_specific.h" 15 #include "partition_alloc/partition_alloc_base/component_export.h" 16 #include "partition_alloc/partition_alloc_base/debug/debugging_buildflags.h" 17 #include "partition_alloc/partition_alloc_base/log_message.h" 18 19 // TODO(1151236): Need to update the description, because logging for PA 20 // standalone library was minimized. 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 // Instructions 46 // ------------ 47 // 48 // Make a bunch of macros for logging. The way to log things is to stream 49 // things to PA_LOG(<a particular severity level>). E.g., 50 // 51 // PA_LOG(INFO) << "Found " << num_cookies << " cookies"; 52 // 53 // You can also do conditional logging: 54 // 55 // PA_LOG_IF(INFO, num_cookies > 10) << "Got lots of cookies"; 56 // 57 // The CHECK(condition) macro is active in both debug and release builds and 58 // effectively performs a PA_LOG(FATAL) which terminates the process and 59 // generates a crashdump unless a debugger is attached. 60 // 61 // There are also "debug mode" logging macros like the ones above: 62 // 63 // PA_DLOG(INFO) << "Found cookies"; 64 // 65 // PA_DLOG_IF(INFO, num_cookies > 10) << "Got lots of cookies"; 66 // 67 // All "debug mode" logging is compiled away to nothing for non-debug mode 68 // compiles. PA_LOG_IF and development flags also work well together 69 // because the code can be compiled away sometimes. 70 // 71 // We also have 72 // 73 // PA_LOG_ASSERT(assertion); 74 // PA_DLOG_ASSERT(assertion); 75 // 76 // which is syntactic sugar for PA_{,D}LOG_IF(FATAL, assert fails) << assertion; 77 // 78 // There are "verbose level" logging macros. They look like 79 // 80 // PA_VLOG(1) << "I'm printed when you run the program with --v=1 or more"; 81 // PA_VLOG(2) << "I'm printed when you run the program with --v=2 or more"; 82 // 83 // These always log at the INFO log level (when they log at all). 84 // 85 // There's also PA_VLOG_IS_ON(n) "verbose level" condition macro. To be used as 86 // 87 // if (PA_VLOG_IS_ON(2)) { 88 // // do some logging preparation and logging 89 // // that can't be accomplished with just PA_VLOG(2) << ...; 90 // } 91 // 92 // There is also a PA_VLOG_IF "verbose level" condition macro for sample 93 // cases, when some extra computation and preparation for logs is not 94 // needed. 95 // 96 // PA_VLOG_IF(1, (size > 1024)) 97 // << "I'm printed when size is more than 1024 and when you run the " 98 // "program with --v=1 or more"; 99 // 100 // We also override the standard 'assert' to use 'PA_DLOG_ASSERT'. 101 // 102 // Lastly, there is: 103 // 104 // PA_PLOG(ERROR) << "Couldn't do foo"; 105 // PA_DPLOG(ERROR) << "Couldn't do foo"; 106 // PA_PLOG_IF(ERROR, cond) << "Couldn't do foo"; 107 // PA_DPLOG_IF(ERROR, cond) << "Couldn't do foo"; 108 // PA_PCHECK(condition) << "Couldn't do foo"; 109 // PA_DPCHECK(condition) << "Couldn't do foo"; 110 // 111 // which append the last system error to the message in string form (taken from 112 // GetLastError() on Windows and errno on POSIX). 113 // 114 // The supported severity levels for macros that allow you to specify one 115 // are (in increasing order of severity) INFO, WARNING, ERROR, and FATAL. 116 // 117 // Very important: logging a message at the FATAL severity level causes 118 // the program to terminate (after the message is logged). 119 // 120 // There is the special severity of DFATAL, which logs FATAL in DCHECK-enabled 121 // builds, ERROR in normal mode. 122 // 123 // Output is formatted as per the following example: 124 // [VERBOSE1:drm_device_handle.cc(90)] Succeeded 125 // authenticating /dev/dri/card0 in 0 ms with 1 attempt(s) 126 // 127 // The colon separated fields inside the brackets are as follows: 128 // 1. The log level 129 // 2. The filename and line number where the log was instantiated 130 // 131 // Additional logging-related information can be found here: 132 // https://chromium.googlesource.com/chromium/src/+/main/docs/linux/debugging.md#Logging 133 134 namespace partition_alloc::internal::logging { 135 136 // Sets the log level. Anything at or above this level will be written to the 137 // log file/displayed to the user (if applicable). Anything below this level 138 // will be silently ignored. The log level defaults to 0 (everything is logged 139 // up to level INFO) if this function is not called. 140 // Note that log messages for VLOG(x) are logged at level -x, so setting 141 // the min log level to negative values enables verbose logging. 142 PA_COMPONENT_EXPORT(PARTITION_ALLOC_BASE) void SetMinLogLevel(int level); 143 144 // Gets the current log level. 145 PA_COMPONENT_EXPORT(PARTITION_ALLOC_BASE) int GetMinLogLevel(); 146 147 // Used by PA_LOG_IS_ON to lazy-evaluate stream arguments. 148 PA_COMPONENT_EXPORT(PARTITION_ALLOC_BASE) 149 bool ShouldCreateLogMessage(int severity); 150 151 // Gets the PA_VLOG default verbosity level. 152 PA_COMPONENT_EXPORT(PARTITION_ALLOC_BASE) int GetVlogVerbosity(); 153 154 // A few definitions of macros that don't generate much code. These are used 155 // by PA_LOG() and LOG_IF, etc. Since these are used all over our code, it's 156 // better to have compact code for these operations. 157 #define PA_COMPACT_GOOGLE_LOG_EX_INFO(ClassName) \ 158 ::partition_alloc::internal::logging::ClassName( \ 159 __FILE__, __LINE__, ::partition_alloc::internal::logging::LOGGING_INFO) 160 #define PA_COMPACT_GOOGLE_PLOG_EX_INFO(ClassName, error_code) \ 161 ::partition_alloc::internal::logging::ClassName( \ 162 __FILE__, __LINE__, ::partition_alloc::internal::logging::LOGGING_INFO, \ 163 error_code) 164 #define PA_COMPACT_GOOGLE_LOG_EX_WARNING(ClassName) \ 165 ::partition_alloc::internal::logging::ClassName( \ 166 __FILE__, __LINE__, \ 167 ::partition_alloc::internal::logging::LOGGING_WARNING) 168 #define PA_COMPACT_GOOGLE_PLOG_EX_WARNING(ClassName, error_code) \ 169 ::partition_alloc::internal::logging::ClassName( \ 170 __FILE__, __LINE__, \ 171 ::partition_alloc::internal::logging::LOGGING_WARNING) 172 #define PA_COMPACT_GOOGLE_LOG_EX_ERROR(ClassName) \ 173 ::partition_alloc::internal::logging::ClassName( \ 174 __FILE__, __LINE__, ::partition_alloc::internal::logging::LOGGING_ERROR) 175 #define PA_COMPACT_GOOGLE_PLOG_EX_ERROR(ClassName, error_code) \ 176 ::partition_alloc::internal::logging::ClassName( \ 177 __FILE__, __LINE__, ::partition_alloc::internal::logging::LOGGING_ERROR, \ 178 error_code) 179 #define PA_COMPACT_GOOGLE_LOG_EX_FATAL(ClassName) \ 180 ::partition_alloc::internal::logging::ClassName( \ 181 __FILE__, __LINE__, ::partition_alloc::internal::logging::LOGGING_FATAL) 182 #define PA_COMPACT_GOOGLE_PLOG_EX_FATAL(ClassName, error_code) \ 183 ::partition_alloc::internal::logging::ClassName( \ 184 __FILE__, __LINE__, ::partition_alloc::internal::logging::LOGGING_FATAL, \ 185 error_code) 186 #define PA_COMPACT_GOOGLE_LOG_EX_DFATAL(ClassName) \ 187 ::partition_alloc::internal::logging::ClassName( \ 188 __FILE__, __LINE__, \ 189 ::partition_alloc::internal::logging::LOGGING_DFATAL) 190 #define PA_COMPACT_GOOGLE_PLOG_EX_DFATAL(ClassName, error_code) \ 191 ::partition_alloc::internal::logging::ClassName( \ 192 __FILE__, __LINE__, \ 193 ::partition_alloc::internal::logging::LOGGING_DFATAL, error_code) 194 #define PA_COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName) \ 195 ::partition_alloc::internal::logging::ClassName( \ 196 __FILE__, __LINE__, \ 197 ::partition_alloc::internal::logging::LOGGING_DCHECK) 198 #define PA_COMPACT_GOOGLE_PLOG_EX_DCHECK(ClassName, error_code) \ 199 ::partition_alloc::internal::logging::ClassName( \ 200 __FILE__, __LINE__, \ 201 ::partition_alloc::internal::logging::LOGGING_DCHECK, error_code) 202 203 #define PA_COMPACT_GOOGLE_LOG_INFO PA_COMPACT_GOOGLE_LOG_EX_INFO(LogMessage) 204 #define PA_COMPACT_GOOGLE_LOG_WARNING \ 205 PA_COMPACT_GOOGLE_LOG_EX_WARNING(LogMessage) 206 #define PA_COMPACT_GOOGLE_LOG_ERROR PA_COMPACT_GOOGLE_LOG_EX_ERROR(LogMessage) 207 #define PA_COMPACT_GOOGLE_LOG_FATAL PA_COMPACT_GOOGLE_LOG_EX_FATAL(LogMessage) 208 #define PA_COMPACT_GOOGLE_LOG_DFATAL PA_COMPACT_GOOGLE_LOG_EX_DFATAL(LogMessage) 209 #define PA_COMPACT_GOOGLE_LOG_DCHECK PA_COMPACT_GOOGLE_LOG_EX_DCHECK(LogMessage) 210 211 #if BUILDFLAG(IS_WIN) 212 // wingdi.h defines ERROR to be 0. When we call PA_LOG(ERROR), it gets 213 // substituted with 0, and it expands to PA_COMPACT_GOOGLE_LOG_0. To allow us 214 // to keep using this syntax, we define this macro to do the same thing 215 // as PA_COMPACT_GOOGLE_LOG_ERROR, and also define ERROR the same way that 216 // the Windows SDK does for consistency. 217 #define PA_ERROR 0 218 #define PA_COMPACT_GOOGLE_LOG_EX_0(ClassName) \ 219 PA_COMPACT_GOOGLE_LOG_EX_ERROR(ClassName) 220 #define PA_COMPACT_GOOGLE_LOG_0 PA_COMPACT_GOOGLE_LOG_ERROR 221 // Needed for LOG_IS_ON(ERROR). 222 constexpr LogSeverity LOGGING_0 = LOGGING_ERROR; 223 #endif 224 225 // As special cases, we can assume that LOG_IS_ON(FATAL) always holds. Also, 226 // LOG_IS_ON(DFATAL) always holds in debug mode. In particular, CHECK()s will 227 // always fire if they fail. 228 #define PA_LOG_IS_ON(severity) \ 229 (::partition_alloc::internal::logging::ShouldCreateLogMessage( \ 230 ::partition_alloc::internal::logging::LOGGING_##severity)) 231 232 // We don't do any caching tricks with VLOG_IS_ON() like the 233 // google-glog version since it increases binary size. This means 234 // that using the v-logging functions in conjunction with --vmodule 235 // may be slow. 236 #define PA_VLOG_IS_ON(verboselevel) \ 237 ((verboselevel) <= ::partition_alloc::internal::logging::GetVlogVerbosity()) 238 239 // Helper macro which avoids evaluating the arguments to a stream if 240 // the condition doesn't hold. Condition is evaluated once and only once. 241 #define PA_LAZY_STREAM(stream, condition) \ 242 !(condition) \ 243 ? (void)0 \ 244 : ::partition_alloc::internal::logging::LogMessageVoidify() & (stream) 245 246 // We use the preprocessor's merging operator, "##", so that, e.g., 247 // PA_LOG(INFO) becomes the token PA_COMPACT_GOOGLE_LOG_INFO. There's some 248 // funny subtle difference between ostream member streaming functions (e.g., 249 // ostream::operator<<(int) and ostream non-member streaming functions 250 // (e.g., ::operator<<(ostream&, string&): it turns out that it's 251 // impossible to stream something like a string directly to an unnamed 252 // ostream. We employ a neat hack by calling the stream() member 253 // function of LogMessage which seems to avoid the problem. 254 #define PA_LOG_STREAM(severity) PA_COMPACT_GOOGLE_LOG_##severity.stream() 255 256 #define PA_LOG(severity) \ 257 PA_LAZY_STREAM(PA_LOG_STREAM(severity), PA_LOG_IS_ON(severity)) 258 #define PA_LOG_IF(severity, condition) \ 259 PA_LAZY_STREAM(PA_LOG_STREAM(severity), PA_LOG_IS_ON(severity) && (condition)) 260 261 // The VLOG macros log with negative verbosities. 262 #define PA_VLOG_STREAM(verbose_level) \ 263 ::partition_alloc::internal::logging::LogMessage(__FILE__, __LINE__, \ 264 -(verbose_level)) \ 265 .stream() 266 267 #define PA_VLOG(verbose_level) \ 268 PA_LAZY_STREAM(PA_VLOG_STREAM(verbose_level), PA_VLOG_IS_ON(verbose_level)) 269 270 #define PA_VLOG_IF(verbose_level, condition) \ 271 PA_LAZY_STREAM(PA_VLOG_STREAM(verbose_level), \ 272 PA_VLOG_IS_ON(verbose_level) && (condition)) 273 274 #if BUILDFLAG(IS_WIN) 275 #define PA_VPLOG_STREAM(verbose_level) \ 276 ::partition_alloc::internal::logging::Win32ErrorLogMessage( \ 277 __FILE__, __LINE__, -(verbose_level), \ 278 ::partition_alloc::internal::logging::GetLastSystemErrorCode()) \ 279 .stream() 280 #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) 281 #define PA_VPLOG_STREAM(verbose_level) \ 282 ::partition_alloc::internal::logging::ErrnoLogMessage( \ 283 __FILE__, __LINE__, -(verbose_level), \ 284 ::partition_alloc::internal::logging::GetLastSystemErrorCode()) \ 285 .stream() 286 #endif 287 288 #define PA_VPLOG(verbose_level) \ 289 PA_LAZY_STREAM(PA_VPLOG_STREAM(verbose_level), PA_VLOG_IS_ON(verbose_level)) 290 291 #define PA_VPLOG_IF(verbose_level, condition) \ 292 PA_LAZY_STREAM(PA_VPLOG_STREAM(verbose_level), \ 293 PA_VLOG_IS_ON(verbose_level) && (condition)) 294 295 // TODO(akalin): Add more VLOG variants, e.g. VPLOG. 296 297 #define PA_LOG_ASSERT(condition) \ 298 PA_LOG_IF(FATAL, !(PA_ANALYZER_ASSUME_TRUE(condition))) \ 299 << "Assert failed: " #condition ". " 300 301 #if BUILDFLAG(IS_WIN) 302 #define PA_PLOG_STREAM(severity) \ 303 PA_COMPACT_GOOGLE_PLOG_EX_##severity( \ 304 Win32ErrorLogMessage, \ 305 ::partition_alloc::internal::logging::GetLastSystemErrorCode()) \ 306 .stream() 307 #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) 308 #define PA_PLOG_STREAM(severity) \ 309 PA_COMPACT_GOOGLE_PLOG_EX_##severity( \ 310 ErrnoLogMessage, \ 311 ::partition_alloc::internal::logging::GetLastSystemErrorCode()) \ 312 .stream() 313 #endif 314 315 #define PA_PLOG(severity) \ 316 PA_LAZY_STREAM(PA_PLOG_STREAM(severity), PA_LOG_IS_ON(severity)) 317 318 #define PA_PLOG_IF(severity, condition) \ 319 PA_LAZY_STREAM(PA_PLOG_STREAM(severity), \ 320 PA_LOG_IS_ON(severity) && (condition)) 321 322 // Note that g_swallow_stream is used instead of an arbitrary PA_LOG() stream to 323 // avoid the creation of an object with a non-trivial destructor (LogMessage). 324 // On MSVC x86 (checked on 2015 Update 3), this causes a few additional 325 // pointless instructions to be emitted even at full optimization level, even 326 // though the : arm of the ternary operator is clearly never executed. Using a 327 // simpler object to be &'d with Voidify() avoids these extra instructions. 328 // Using a simpler POD object with a templated operator<< also works to avoid 329 // these instructions. However, this causes warnings on statically defined 330 // implementations of operator<<(std::ostream, ...) in some .cc files, because 331 // they become defined-but-unreferenced functions. A reinterpret_cast of 0 to an 332 // ostream* also is not suitable, because some compilers warn of undefined 333 // behavior. 334 #define PA_EAT_STREAM_PARAMETERS \ 335 true ? (void)0 \ 336 : ::partition_alloc::internal::logging::LogMessageVoidify() & \ 337 (*::partition_alloc::internal::logging::g_swallow_stream) 338 339 // Definitions for DLOG et al. 340 341 #if BUILDFLAG(PA_DCHECK_IS_ON) 342 343 #define PA_DLOG_IS_ON(severity) PA_LOG_IS_ON(severity) 344 #define PA_DLOG_IF(severity, condition) PA_LOG_IF(severity, condition) 345 #define PA_DLOG_ASSERT(condition) PA_LOG_ASSERT(condition) 346 #define PA_DPLOG_IF(severity, condition) PA_PLOG_IF(severity, condition) 347 #define PA_DVLOG_IF(verboselevel, condition) PA_VLOG_IF(verboselevel, condition) 348 #define PA_DVPLOG_IF(verboselevel, condition) \ 349 PA_VPLOG_IF(verboselevel, condition) 350 351 #else // BUILDFLAG(PA_DCHECK_IS_ON) 352 353 // If !BUILDFLAG(PA_DCHECK_IS_ON), we want to avoid emitting any references to 354 // |condition| (which may reference a variable defined only if 355 // BUILDFLAG(PA_DCHECK_IS_ON)). Contrast this with DCHECK et al., which has 356 // different behavior. 357 358 #define PA_DLOG_IS_ON(severity) false 359 #define PA_DLOG_IF(severity, condition) PA_EAT_STREAM_PARAMETERS 360 #define PA_DLOG_ASSERT(condition) PA_EAT_STREAM_PARAMETERS 361 #define PA_DPLOG_IF(severity, condition) PA_EAT_STREAM_PARAMETERS 362 #define PA_DVLOG_IF(verboselevel, condition) PA_EAT_STREAM_PARAMETERS 363 #define PA_DVPLOG_IF(verboselevel, condition) PA_EAT_STREAM_PARAMETERS 364 365 #endif // BUILDFLAG(PA_DCHECK_IS_ON) 366 367 #define PA_DLOG(severity) \ 368 PA_LAZY_STREAM(PA_LOG_STREAM(severity), PA_DLOG_IS_ON(severity)) 369 370 #define PA_DPLOG(severity) \ 371 PA_LAZY_STREAM(PA_PLOG_STREAM(severity), PA_DLOG_IS_ON(severity)) 372 373 #define PA_DVLOG(verboselevel) PA_DVLOG_IF(verboselevel, true) 374 375 #define PA_DVPLOG(verboselevel) PA_DVPLOG_IF(verboselevel, true) 376 377 // Definitions for DCHECK et al. 378 379 #if BUILDFLAG(PA_DCHECK_IS_CONFIGURABLE) 380 PA_COMPONENT_EXPORT(PARTITION_ALLOC_BASE) extern LogSeverity LOGGING_DCHECK; 381 #else 382 constexpr LogSeverity LOGGING_DCHECK = LOGGING_FATAL; 383 #endif // BUILDFLAG(PA_DCHECK_IS_CONFIGURABLE) 384 385 // Redefine the standard assert to use our nice log files 386 #undef assert 387 #define assert(x) PA_DLOG_ASSERT(x) 388 389 // Async signal safe logging mechanism. 390 PA_COMPONENT_EXPORT(PARTITION_ALLOC_BASE) 391 void RawLog(int level, const char* message); 392 393 #define PA_RAW_LOG(level, message) \ 394 ::partition_alloc::internal::logging::RawLog( \ 395 ::partition_alloc::internal::logging::LOGGING_##level, message) 396 397 } // namespace partition_alloc::internal::logging 398 399 #endif // BASE_ALLOCATOR_PARTITION_ALLOCATOR_SRC_PARTITION_ALLOC_PARTITION_ALLOC_BASE_LOGGING_H_ 400