Fairphone ODM | 25c12f5 | 2023-12-15 17:24:06 +0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2015 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #pragma once |
| 18 | |
| 19 | // |
| 20 | // Google-style C++ logging. |
| 21 | // |
| 22 | |
| 23 | // This header provides a C++ stream interface to logging. |
| 24 | // |
| 25 | // To log: |
| 26 | // |
| 27 | // LOG(INFO) << "Some text; " << some_value; |
| 28 | // |
| 29 | // Replace `INFO` with any severity from `enum LogSeverity`. |
| 30 | // Most devices filter out VERBOSE logs by default, run |
| 31 | // `adb shell setprop log.tag.<TAG> V` to see them in adb logcat. |
| 32 | // |
| 33 | // To log the result of a failed function and include the string |
| 34 | // representation of `errno` at the end: |
| 35 | // |
| 36 | // PLOG(ERROR) << "Write failed"; |
| 37 | // |
| 38 | // The output will be something like `Write failed: I/O error`. |
| 39 | // Remember this as 'P' as in perror(3). |
| 40 | // |
| 41 | // To output your own types, simply implement operator<< as normal. |
| 42 | // |
| 43 | // By default, output goes to logcat on Android and stderr on the host. |
| 44 | // A process can use `SetLogger` to decide where all logging goes. |
| 45 | // Implementations are provided for logcat, stderr, and dmesg. |
| 46 | // |
| 47 | // By default, the process' name is used as the log tag. |
| 48 | // Code can choose a specific log tag by defining LOG_TAG |
| 49 | // before including this header. |
| 50 | |
| 51 | // This header also provides assertions: |
| 52 | // |
| 53 | // CHECK(must_be_true); |
| 54 | // CHECK_EQ(a, b) << z_is_interesting_too; |
| 55 | |
| 56 | // NOTE: For Windows, you must include logging.h after windows.h to allow the |
| 57 | // following code to suppress the evil ERROR macro: |
| 58 | #ifdef _WIN32 |
| 59 | // windows.h includes wingdi.h which defines an evil macro ERROR. |
| 60 | #ifdef ERROR |
| 61 | #undef ERROR |
| 62 | #endif |
| 63 | #endif |
| 64 | |
| 65 | #include <functional> |
| 66 | #include <memory> |
| 67 | #include <ostream> |
| 68 | |
| 69 | #include "android-base/errno_restorer.h" |
| 70 | #include "android-base/macros.h" |
| 71 | |
| 72 | // Note: DO NOT USE DIRECTLY. Use LOG_TAG instead. |
| 73 | #ifdef _LOG_TAG_INTERNAL |
| 74 | #error "_LOG_TAG_INTERNAL must not be defined" |
| 75 | #endif |
| 76 | #ifdef LOG_TAG |
| 77 | #define _LOG_TAG_INTERNAL LOG_TAG |
| 78 | #else |
| 79 | #define _LOG_TAG_INTERNAL nullptr |
| 80 | #endif |
| 81 | |
| 82 | namespace android { |
| 83 | namespace base { |
| 84 | |
| 85 | enum LogSeverity { |
| 86 | VERBOSE, |
| 87 | DEBUG, |
| 88 | INFO, |
| 89 | WARNING, |
| 90 | ERROR, |
| 91 | FATAL_WITHOUT_ABORT, // For loggability tests, this is considered identical to FATAL. |
| 92 | FATAL, |
| 93 | }; |
| 94 | |
| 95 | enum LogId { |
| 96 | DEFAULT, |
| 97 | MAIN, |
| 98 | SYSTEM, |
| 99 | RADIO, |
| 100 | CRASH, |
| 101 | }; |
| 102 | |
| 103 | using LogFunction = std::function<void(LogId /*log_buffer_id*/, |
| 104 | LogSeverity /*severity*/, |
| 105 | const char* /*tag*/, |
| 106 | const char* /*file*/, |
| 107 | unsigned int /*line*/, |
| 108 | const char* /*message*/)>; |
| 109 | using AbortFunction = std::function<void(const char* /*abort_message*/)>; |
| 110 | |
| 111 | // Loggers for use with InitLogging/SetLogger. |
| 112 | |
| 113 | // Log to the kernel log (dmesg). |
| 114 | void KernelLogger(LogId log_buffer_id, LogSeverity severity, const char* tag, const char* file, unsigned int line, const char* message); |
| 115 | // Log to stderr in the full logcat format (with pid/tid/time/tag details). |
| 116 | void StderrLogger(LogId log_buffer_id, LogSeverity severity, const char* tag, const char* file, unsigned int line, const char* message); |
| 117 | // Log just the message to stdout/stderr (without pid/tid/time/tag details). |
| 118 | // The choice of stdout versus stderr is based on the severity. |
| 119 | // Errors are also prefixed by the program name (as with err(3)/error(3)). |
| 120 | // Useful for replacing printf(3)/perror(3)/err(3)/error(3) in command-line tools. |
| 121 | void StdioLogger(LogId log_buffer_id, LogSeverity severity, const char* tag, const char* file, unsigned int line, const char* message); |
| 122 | |
| 123 | void DefaultAborter(const char* abort_message); |
| 124 | |
| 125 | void SetDefaultTag(const std::string& tag); |
| 126 | |
| 127 | // The LogdLogger sends chunks of up to ~4000 bytes at a time to logd. It does not prevent other |
| 128 | // threads from writing to logd between sending each chunk, so other threads may interleave their |
| 129 | // messages. If preventing interleaving is required, then a custom logger that takes a lock before |
| 130 | // calling this logger should be provided. |
| 131 | class LogdLogger { |
| 132 | public: |
| 133 | explicit LogdLogger(LogId default_log_id = android::base::MAIN); |
| 134 | |
| 135 | void operator()(LogId, LogSeverity, const char* tag, const char* file, |
| 136 | unsigned int line, const char* message); |
| 137 | |
| 138 | private: |
| 139 | LogId default_log_id_; |
| 140 | }; |
| 141 | |
| 142 | // Configure logging based on ANDROID_LOG_TAGS environment variable. |
| 143 | // We need to parse a string that looks like |
| 144 | // |
| 145 | // *:v jdwp:d dalvikvm:d dalvikvm-gc:i dalvikvmi:i |
| 146 | // |
| 147 | // The tag (or '*' for the global level) comes first, followed by a colon and a |
| 148 | // letter indicating the minimum priority level we're expected to log. This can |
| 149 | // be used to reveal or conceal logs with specific tags. |
| 150 | #ifdef __ANDROID__ |
| 151 | #define INIT_LOGGING_DEFAULT_LOGGER LogdLogger() |
| 152 | #else |
| 153 | #define INIT_LOGGING_DEFAULT_LOGGER StderrLogger |
| 154 | #endif |
| 155 | void InitLogging(char* argv[], |
| 156 | LogFunction&& logger = INIT_LOGGING_DEFAULT_LOGGER, |
| 157 | AbortFunction&& aborter = DefaultAborter); |
| 158 | #undef INIT_LOGGING_DEFAULT_LOGGER |
| 159 | |
| 160 | // Replace the current logger and return the old one. |
| 161 | LogFunction SetLogger(LogFunction&& logger); |
| 162 | |
| 163 | // Replace the current aborter and return the old one. |
| 164 | AbortFunction SetAborter(AbortFunction&& aborter); |
| 165 | |
| 166 | // A helper macro that produces an expression that accepts both a qualified name and an |
| 167 | // unqualified name for a LogSeverity, and returns a LogSeverity value. |
| 168 | // Note: DO NOT USE DIRECTLY. This is an implementation detail. |
| 169 | #define SEVERITY_LAMBDA(severity) ([&]() { \ |
| 170 | using ::android::base::VERBOSE; \ |
| 171 | using ::android::base::DEBUG; \ |
| 172 | using ::android::base::INFO; \ |
| 173 | using ::android::base::WARNING; \ |
| 174 | using ::android::base::ERROR; \ |
| 175 | using ::android::base::FATAL_WITHOUT_ABORT; \ |
| 176 | using ::android::base::FATAL; \ |
| 177 | return (severity); }()) |
| 178 | |
| 179 | #ifdef __clang_analyzer__ |
| 180 | // Clang's static analyzer does not see the conditional statement inside |
| 181 | // LogMessage's destructor that will abort on FATAL severity. |
| 182 | #define ABORT_AFTER_LOG_FATAL for (;; abort()) |
| 183 | |
| 184 | struct LogAbortAfterFullExpr { |
| 185 | ~LogAbortAfterFullExpr() __attribute__((noreturn)) { abort(); } |
| 186 | explicit operator bool() const { return false; } |
| 187 | }; |
| 188 | // Provides an expression that evaluates to the truthiness of `x`, automatically |
| 189 | // aborting if `c` is true. |
| 190 | #define ABORT_AFTER_LOG_EXPR_IF(c, x) (((c) && ::android::base::LogAbortAfterFullExpr()) || (x)) |
| 191 | // Note to the static analyzer that we always execute FATAL logs in practice. |
| 192 | #define MUST_LOG_MESSAGE(severity) (SEVERITY_LAMBDA(severity) == ::android::base::FATAL) |
| 193 | #else |
| 194 | #define ABORT_AFTER_LOG_FATAL |
| 195 | #define ABORT_AFTER_LOG_EXPR_IF(c, x) (x) |
| 196 | #define MUST_LOG_MESSAGE(severity) false |
| 197 | #endif |
| 198 | #define ABORT_AFTER_LOG_FATAL_EXPR(x) ABORT_AFTER_LOG_EXPR_IF(true, x) |
| 199 | |
| 200 | // Defines whether the given severity will be logged or silently swallowed. |
| 201 | #define WOULD_LOG(severity) \ |
| 202 | (UNLIKELY(::android::base::ShouldLog(SEVERITY_LAMBDA(severity), _LOG_TAG_INTERNAL)) || \ |
| 203 | MUST_LOG_MESSAGE(severity)) |
| 204 | |
| 205 | // Get an ostream that can be used for logging at the given severity and to the default |
| 206 | // destination. |
| 207 | // |
| 208 | // Notes: |
| 209 | // 1) This will not check whether the severity is high enough. One should use WOULD_LOG to filter |
| 210 | // usage manually. |
| 211 | // 2) This does not save and restore errno. |
| 212 | #define LOG_STREAM(severity) \ |
| 213 | ::android::base::LogMessage(__FILE__, __LINE__, SEVERITY_LAMBDA(severity), _LOG_TAG_INTERNAL, \ |
| 214 | -1) \ |
| 215 | .stream() |
| 216 | |
| 217 | // Logs a message to logcat on Android otherwise to stderr. If the severity is |
| 218 | // FATAL it also causes an abort. For example: |
| 219 | // |
| 220 | // LOG(FATAL) << "We didn't expect to reach here"; |
| 221 | #define LOG(severity) LOGGING_PREAMBLE(severity) && LOG_STREAM(severity) |
| 222 | |
| 223 | // Checks if we want to log something, and sets up appropriate RAII objects if |
| 224 | // so. |
| 225 | // Note: DO NOT USE DIRECTLY. This is an implementation detail. |
| 226 | #define LOGGING_PREAMBLE(severity) \ |
| 227 | (WOULD_LOG(severity) && \ |
| 228 | ABORT_AFTER_LOG_EXPR_IF((SEVERITY_LAMBDA(severity)) == ::android::base::FATAL, true) && \ |
| 229 | ::android::base::ErrnoRestorer()) |
| 230 | |
| 231 | // A variant of LOG that also logs the current errno value. To be used when |
| 232 | // library calls fail. |
| 233 | #define PLOG(severity) \ |
| 234 | LOGGING_PREAMBLE(severity) && \ |
| 235 | ::android::base::LogMessage(__FILE__, __LINE__, SEVERITY_LAMBDA(severity), \ |
| 236 | _LOG_TAG_INTERNAL, errno) \ |
| 237 | .stream() |
| 238 | |
| 239 | // Marker that code is yet to be implemented. |
| 240 | #define UNIMPLEMENTED(level) \ |
| 241 | LOG(level) << __PRETTY_FUNCTION__ << " unimplemented " |
| 242 | |
| 243 | // Check whether condition x holds and LOG(FATAL) if not. The value of the |
| 244 | // expression x is only evaluated once. Extra logging can be appended using << |
| 245 | // after. For example: |
| 246 | // |
| 247 | // CHECK(false == true) results in a log message of |
| 248 | // "Check failed: false == true". |
| 249 | #define CHECK(x) \ |
| 250 | LIKELY((x)) || ABORT_AFTER_LOG_FATAL_EXPR(false) || \ |
| 251 | ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::FATAL, _LOG_TAG_INTERNAL, \ |
| 252 | -1) \ |
| 253 | .stream() \ |
| 254 | << "Check failed: " #x << " " |
| 255 | |
| 256 | // clang-format off |
| 257 | // Helper for CHECK_xx(x,y) macros. |
| 258 | #define CHECK_OP(LHS, RHS, OP) \ |
| 259 | for (auto _values = ::android::base::MakeEagerEvaluator(LHS, RHS); \ |
| 260 | UNLIKELY(!(_values.lhs.v OP _values.rhs.v)); \ |
| 261 | /* empty */) \ |
| 262 | ABORT_AFTER_LOG_FATAL \ |
| 263 | ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::FATAL, _LOG_TAG_INTERNAL, -1) \ |
| 264 | .stream() \ |
| 265 | << "Check failed: " << #LHS << " " << #OP << " " << #RHS << " (" #LHS "=" \ |
| 266 | << ::android::base::LogNullGuard<decltype(_values.lhs.v)>::Guard(_values.lhs.v) \ |
| 267 | << ", " #RHS "=" \ |
| 268 | << ::android::base::LogNullGuard<decltype(_values.rhs.v)>::Guard(_values.rhs.v) \ |
| 269 | << ") " |
| 270 | // clang-format on |
| 271 | |
| 272 | // Check whether a condition holds between x and y, LOG(FATAL) if not. The value |
| 273 | // of the expressions x and y is evaluated once. Extra logging can be appended |
| 274 | // using << after. For example: |
| 275 | // |
| 276 | // CHECK_NE(0 == 1, false) results in |
| 277 | // "Check failed: false != false (0==1=false, false=false) ". |
| 278 | #define CHECK_EQ(x, y) CHECK_OP(x, y, == ) |
| 279 | #define CHECK_NE(x, y) CHECK_OP(x, y, != ) |
| 280 | #define CHECK_LE(x, y) CHECK_OP(x, y, <= ) |
| 281 | #define CHECK_LT(x, y) CHECK_OP(x, y, < ) |
| 282 | #define CHECK_GE(x, y) CHECK_OP(x, y, >= ) |
| 283 | #define CHECK_GT(x, y) CHECK_OP(x, y, > ) |
| 284 | |
| 285 | // clang-format off |
| 286 | // Helper for CHECK_STRxx(s1,s2) macros. |
| 287 | #define CHECK_STROP(s1, s2, sense) \ |
| 288 | while (UNLIKELY((strcmp(s1, s2) == 0) != (sense))) \ |
| 289 | ABORT_AFTER_LOG_FATAL \ |
| 290 | ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::FATAL, \ |
| 291 | _LOG_TAG_INTERNAL, -1) \ |
| 292 | .stream() \ |
| 293 | << "Check failed: " << "\"" << (s1) << "\"" \ |
| 294 | << ((sense) ? " == " : " != ") << "\"" << (s2) << "\"" |
| 295 | // clang-format on |
| 296 | |
| 297 | // Check for string (const char*) equality between s1 and s2, LOG(FATAL) if not. |
| 298 | #define CHECK_STREQ(s1, s2) CHECK_STROP(s1, s2, true) |
| 299 | #define CHECK_STRNE(s1, s2) CHECK_STROP(s1, s2, false) |
| 300 | |
| 301 | // Perform the pthread function call(args), LOG(FATAL) on error. |
| 302 | #define CHECK_PTHREAD_CALL(call, args, what) \ |
| 303 | do { \ |
| 304 | int rc = call args; \ |
| 305 | if (rc != 0) { \ |
| 306 | errno = rc; \ |
| 307 | ABORT_AFTER_LOG_FATAL \ |
| 308 | PLOG(FATAL) << #call << " failed for " << (what); \ |
| 309 | } \ |
| 310 | } while (false) |
| 311 | |
| 312 | // DCHECKs are debug variants of CHECKs only enabled in debug builds. Generally |
| 313 | // CHECK should be used unless profiling identifies a CHECK as being in |
| 314 | // performance critical code. |
| 315 | #if defined(NDEBUG) && !defined(__clang_analyzer__) |
| 316 | static constexpr bool kEnableDChecks = false; |
| 317 | #else |
| 318 | static constexpr bool kEnableDChecks = true; |
| 319 | #endif |
| 320 | |
| 321 | #define DCHECK(x) \ |
| 322 | if (::android::base::kEnableDChecks) CHECK(x) |
| 323 | #define DCHECK_EQ(x, y) \ |
| 324 | if (::android::base::kEnableDChecks) CHECK_EQ(x, y) |
| 325 | #define DCHECK_NE(x, y) \ |
| 326 | if (::android::base::kEnableDChecks) CHECK_NE(x, y) |
| 327 | #define DCHECK_LE(x, y) \ |
| 328 | if (::android::base::kEnableDChecks) CHECK_LE(x, y) |
| 329 | #define DCHECK_LT(x, y) \ |
| 330 | if (::android::base::kEnableDChecks) CHECK_LT(x, y) |
| 331 | #define DCHECK_GE(x, y) \ |
| 332 | if (::android::base::kEnableDChecks) CHECK_GE(x, y) |
| 333 | #define DCHECK_GT(x, y) \ |
| 334 | if (::android::base::kEnableDChecks) CHECK_GT(x, y) |
| 335 | #define DCHECK_STREQ(s1, s2) \ |
| 336 | if (::android::base::kEnableDChecks) CHECK_STREQ(s1, s2) |
| 337 | #define DCHECK_STRNE(s1, s2) \ |
| 338 | if (::android::base::kEnableDChecks) CHECK_STRNE(s1, s2) |
| 339 | |
| 340 | namespace log_detail { |
| 341 | |
| 342 | // Temporary storage for a single eagerly evaluated check expression operand. |
| 343 | template <typename T> struct Storage { |
| 344 | template <typename U> explicit constexpr Storage(U&& u) : v(std::forward<U>(u)) {} |
| 345 | explicit Storage(const Storage& t) = delete; |
| 346 | explicit Storage(Storage&& t) = delete; |
| 347 | T v; |
| 348 | }; |
| 349 | |
| 350 | // Partial specialization for smart pointers to avoid copying. |
| 351 | template <typename T> struct Storage<std::unique_ptr<T>> { |
| 352 | explicit constexpr Storage(const std::unique_ptr<T>& ptr) : v(ptr.get()) {} |
| 353 | const T* v; |
| 354 | }; |
| 355 | template <typename T> struct Storage<std::shared_ptr<T>> { |
| 356 | explicit constexpr Storage(const std::shared_ptr<T>& ptr) : v(ptr.get()) {} |
| 357 | const T* v; |
| 358 | }; |
| 359 | |
| 360 | // Type trait that checks if a type is a (potentially const) char pointer. |
| 361 | template <typename T> struct IsCharPointer { |
| 362 | using Pointee = std::remove_cv_t<std::remove_pointer_t<T>>; |
| 363 | static constexpr bool value = std::is_pointer_v<T> && |
| 364 | (std::is_same_v<Pointee, char> || std::is_same_v<Pointee, signed char> || |
| 365 | std::is_same_v<Pointee, unsigned char>); |
| 366 | }; |
| 367 | |
| 368 | // Counterpart to Storage that depends on both operands. This is used to prevent |
| 369 | // char pointers being treated as strings in the log output - they might point |
| 370 | // to buffers of unprintable binary data. |
| 371 | template <typename LHS, typename RHS> struct StorageTypes { |
| 372 | static constexpr bool voidptr = IsCharPointer<LHS>::value && IsCharPointer<RHS>::value; |
| 373 | using LHSType = std::conditional_t<voidptr, const void*, LHS>; |
| 374 | using RHSType = std::conditional_t<voidptr, const void*, RHS>; |
| 375 | }; |
| 376 | |
| 377 | // Temporary class created to evaluate the LHS and RHS, used with |
| 378 | // MakeEagerEvaluator to infer the types of LHS and RHS. |
| 379 | template <typename LHS, typename RHS> |
| 380 | struct EagerEvaluator { |
| 381 | template <typename A, typename B> constexpr EagerEvaluator(A&& l, B&& r) |
| 382 | : lhs(std::forward<A>(l)), rhs(std::forward<B>(r)) {} |
| 383 | const Storage<typename StorageTypes<LHS, RHS>::LHSType> lhs; |
| 384 | const Storage<typename StorageTypes<LHS, RHS>::RHSType> rhs; |
| 385 | }; |
| 386 | |
| 387 | } // namespace log_detail |
| 388 | |
| 389 | // Converts std::nullptr_t and null char pointers to the string "null" |
| 390 | // when writing the failure message. |
| 391 | template <typename T> struct LogNullGuard { |
| 392 | static const T& Guard(const T& v) { return v; } |
| 393 | }; |
| 394 | template <> struct LogNullGuard<std::nullptr_t> { |
| 395 | static const char* Guard(const std::nullptr_t&) { return "(null)"; } |
| 396 | }; |
| 397 | template <> struct LogNullGuard<char*> { |
| 398 | static const char* Guard(const char* v) { return v ? v : "(null)"; } |
| 399 | }; |
| 400 | template <> struct LogNullGuard<const char*> { |
| 401 | static const char* Guard(const char* v) { return v ? v : "(null)"; } |
| 402 | }; |
| 403 | |
| 404 | // Helper function for CHECK_xx. |
| 405 | template <typename LHS, typename RHS> |
| 406 | constexpr auto MakeEagerEvaluator(LHS&& lhs, RHS&& rhs) { |
| 407 | return log_detail::EagerEvaluator<std::decay_t<LHS>, std::decay_t<RHS>>( |
| 408 | std::forward<LHS>(lhs), std::forward<RHS>(rhs)); |
| 409 | } |
| 410 | |
| 411 | // Data for the log message, not stored in LogMessage to avoid increasing the |
| 412 | // stack size. |
| 413 | class LogMessageData; |
| 414 | |
| 415 | // A LogMessage is a temporarily scoped object used by LOG and the unlikely part |
| 416 | // of a CHECK. The destructor will abort if the severity is FATAL. |
| 417 | class LogMessage { |
| 418 | public: |
| 419 | // LogId has been deprecated, but this constructor must exist for prebuilts. |
| 420 | LogMessage(const char* file, unsigned int line, LogId, LogSeverity severity, const char* tag, |
| 421 | int error); |
| 422 | LogMessage(const char* file, unsigned int line, LogSeverity severity, const char* tag, int error); |
| 423 | |
| 424 | ~LogMessage(); |
| 425 | |
| 426 | // Returns the stream associated with the message, the LogMessage performs |
| 427 | // output when it goes out of scope. |
| 428 | std::ostream& stream(); |
| 429 | |
| 430 | // The routine that performs the actual logging. |
| 431 | static void LogLine(const char* file, unsigned int line, LogSeverity severity, const char* tag, |
| 432 | const char* msg); |
| 433 | |
| 434 | private: |
| 435 | const std::unique_ptr<LogMessageData> data_; |
| 436 | |
| 437 | DISALLOW_COPY_AND_ASSIGN(LogMessage); |
| 438 | }; |
| 439 | |
| 440 | // Get the minimum severity level for logging. |
| 441 | LogSeverity GetMinimumLogSeverity(); |
| 442 | |
| 443 | // Set the minimum severity level for logging, returning the old severity. |
| 444 | LogSeverity SetMinimumLogSeverity(LogSeverity new_severity); |
| 445 | |
| 446 | // Return whether or not a log message with the associated tag should be logged. |
| 447 | bool ShouldLog(LogSeverity severity, const char* tag); |
| 448 | |
| 449 | // Allows to temporarily change the minimum severity level for logging. |
| 450 | class ScopedLogSeverity { |
| 451 | public: |
| 452 | explicit ScopedLogSeverity(LogSeverity level); |
| 453 | ~ScopedLogSeverity(); |
| 454 | |
| 455 | private: |
| 456 | LogSeverity old_; |
| 457 | }; |
| 458 | |
| 459 | } // namespace base |
| 460 | } // namespace android |
| 461 | |
| 462 | namespace std { // NOLINT(cert-dcl58-cpp) |
| 463 | |
| 464 | // Emit a warning of ostream<< with std::string*. The intention was most likely to print *string. |
| 465 | // |
| 466 | // Note: for this to work, we need to have this in a namespace. |
| 467 | // Note: using a pragma because "-Wgcc-compat" (included in "-Weverything") complains about |
| 468 | // diagnose_if. |
| 469 | // Note: to print the pointer, use "<< static_cast<const void*>(string_pointer)" instead. |
| 470 | // Note: a not-recommended alternative is to let Clang ignore the warning by adding |
| 471 | // -Wno-user-defined-warnings to CPPFLAGS. |
| 472 | #pragma clang diagnostic push |
| 473 | #pragma clang diagnostic ignored "-Wgcc-compat" |
| 474 | #define OSTREAM_STRING_POINTER_USAGE_WARNING \ |
| 475 | __attribute__((diagnose_if(true, "Unexpected logging of string pointer", "warning"))) |
| 476 | inline OSTREAM_STRING_POINTER_USAGE_WARNING |
| 477 | std::ostream& operator<<(std::ostream& stream, const std::string* string_pointer) { |
| 478 | return stream << static_cast<const void*>(string_pointer); |
| 479 | } |
| 480 | #pragma clang diagnostic pop |
| 481 | |
| 482 | } // namespace std |