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Diffstat (limited to 'gn/src/base/logging.h')
| -rw-r--r-- | gn/src/base/logging.h | 922 |
1 files changed, 922 insertions, 0 deletions
diff --git a/gn/src/base/logging.h b/gn/src/base/logging.h new file mode 100644 index 00000000000..78cad59d179 --- /dev/null +++ b/gn/src/base/logging.h @@ -0,0 +1,922 @@ +// Copyright (c) 2012 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#ifndef BASE_LOGGING_H_ +#define BASE_LOGGING_H_ + +#include <stddef.h> + +#include <cassert> +#include <cstring> +#include <sstream> +#include <string> +#include <string_view> +#include <type_traits> +#include <utility> + +#include "base/compiler_specific.h" +#include "base/macros.h" +#include "base/template_util.h" +#include "util/build_config.h" + +// +// Optional message capabilities +// ----------------------------- +// Assertion failed messages and fatal errors are displayed in a dialog box +// before the application exits. However, running this UI creates a message +// loop, which causes application messages to be processed and potentially +// dispatched to existing application windows. Since the application is in a +// bad state when this assertion dialog is displayed, these messages may not +// get processed and hang the dialog, or the application might go crazy. +// +// Therefore, it can be beneficial to display the error dialog in a separate +// process from the main application. When the logging system needs to display +// a fatal error dialog box, it will look for a program called +// "DebugMessage.exe" in the same directory as the application executable. It +// will run this application with the message as the command line, and will +// not include the name of the application as is traditional for easier +// parsing. +// +// The code for DebugMessage.exe is only one line. In WinMain, do: +// MessageBox(NULL, GetCommandLineW(), L"Fatal Error", 0); +// +// If DebugMessage.exe is not found, the logging code will use a normal +// MessageBox, potentially causing the problems discussed above. + +// Instructions +// ------------ +// +// Make a bunch of macros for logging. The way to log things is to stream +// things to LOG(<a particular severity level>). E.g., +// +// LOG(INFO) << "Found " << num_cookies << " cookies"; +// +// You can also do conditional logging: +// +// LOG_IF(INFO, num_cookies > 10) << "Got lots of cookies"; +// +// The CHECK(condition) macro is active in both debug and release builds and +// effectively performs a LOG(FATAL) which terminates the process and +// generates a crashdump unless a debugger is attached. +// +// There are also "debug mode" logging macros like the ones above: +// +// DLOG(INFO) << "Found cookies"; +// +// DLOG_IF(INFO, num_cookies > 10) << "Got lots of cookies"; +// +// All "debug mode" logging is compiled away to nothing for non-debug mode +// compiles. LOG_IF and development flags also work well together +// because the code can be compiled away sometimes. +// +// We also have +// +// LOG_ASSERT(assertion); +// DLOG_ASSERT(assertion); +// +// which is syntactic sugar for {,D}LOG_IF(FATAL, assert fails) << assertion; +// +// We also override the standard 'assert' to use 'DLOG_ASSERT'. +// +// Lastly, there is: +// +// PLOG(ERROR) << "Couldn't do foo"; +// DPLOG(ERROR) << "Couldn't do foo"; +// PLOG_IF(ERROR, cond) << "Couldn't do foo"; +// DPLOG_IF(ERROR, cond) << "Couldn't do foo"; +// PCHECK(condition) << "Couldn't do foo"; +// DPCHECK(condition) << "Couldn't do foo"; +// +// which append the last system error to the message in string form (taken from +// GetLastError() on Windows and errno on POSIX). +// +// The supported severity levels for macros that allow you to specify one +// are (in increasing order of severity) INFO, WARNING, ERROR, and FATAL. +// +// Very important: logging a message at the FATAL severity level causes +// the program to terminate (after the message is logged). +// +// There is the special severity of DFATAL, which logs FATAL in debug mode, +// ERROR in normal mode. + +namespace logging { + +// Sets the log level. Anything at or above this level will be written to the +// log file/displayed to the user (if applicable). Anything below this level +// will be silently ignored. The log level defaults to 0 (everything is logged +// up to level INFO) if this function is not called. +void SetMinLogLevel(int level); + +// Gets the current log level. +int GetMinLogLevel(); + +// Used by LOG_IS_ON to lazy-evaluate stream arguments. +bool ShouldCreateLogMessage(int severity); + +// The ANALYZER_ASSUME_TRUE(bool arg) macro adds compiler-specific hints +// to Clang which control what code paths are statically analyzed, +// and is meant to be used in conjunction with assert & assert-like functions. +// The expression is passed straight through if analysis isn't enabled. +// +// ANALYZER_SKIP_THIS_PATH() suppresses static analysis for the current +// codepath and any other branching codepaths that might follow. +#if defined(__clang_analyzer__) + +inline constexpr bool AnalyzerNoReturn() __attribute__((analyzer_noreturn)) { + return false; +} + +inline constexpr bool AnalyzerAssumeTrue(bool arg) { + // AnalyzerNoReturn() is invoked and analysis is terminated if |arg| is + // false. + return arg || AnalyzerNoReturn(); +} + +#define ANALYZER_ASSUME_TRUE(arg) logging::AnalyzerAssumeTrue(!!(arg)) +#define ANALYZER_SKIP_THIS_PATH() \ + static_cast<void>(::logging::AnalyzerNoReturn()) +#define ANALYZER_ALLOW_UNUSED(var) static_cast<void>(var); + +#else // !defined(__clang_analyzer__) + +#define ANALYZER_ASSUME_TRUE(arg) (arg) +#define ANALYZER_SKIP_THIS_PATH() +#define ANALYZER_ALLOW_UNUSED(var) static_cast<void>(var); + +#endif // defined(__clang_analyzer__) + +typedef int LogSeverity; +const LogSeverity LOG_VERBOSE = -1; // This is level 1 verbosity +// Note: the log severities are used to index into the array of names, +// see log_severity_names. +const LogSeverity LOG_INFO = 0; +const LogSeverity LOG_WARNING = 1; +const LogSeverity LOG_ERROR = 2; +const LogSeverity LOG_FATAL = 3; +const LogSeverity LOG_NUM_SEVERITIES = 4; + +// LOG_DFATAL is LOG_FATAL in debug mode, ERROR in normal mode +#if defined(NDEBUG) +const LogSeverity LOG_DFATAL = LOG_ERROR; +#else +const LogSeverity LOG_DFATAL = LOG_FATAL; +#endif + +// A few definitions of macros that don't generate much code. These are used +// by LOG() and LOG_IF, etc. Since these are used all over our code, it's +// better to have compact code for these operations. +#define COMPACT_GOOGLE_LOG_EX_INFO(ClassName, ...) \ + ::logging::ClassName(__FILE__, __LINE__, ::logging::LOG_INFO, ##__VA_ARGS__) +#define COMPACT_GOOGLE_LOG_EX_WARNING(ClassName, ...) \ + ::logging::ClassName(__FILE__, __LINE__, ::logging::LOG_WARNING, \ + ##__VA_ARGS__) +#define COMPACT_GOOGLE_LOG_EX_ERROR(ClassName, ...) \ + ::logging::ClassName(__FILE__, __LINE__, ::logging::LOG_ERROR, ##__VA_ARGS__) +#define COMPACT_GOOGLE_LOG_EX_FATAL(ClassName, ...) \ + ::logging::ClassName(__FILE__, __LINE__, ::logging::LOG_FATAL, ##__VA_ARGS__) +#define COMPACT_GOOGLE_LOG_EX_DFATAL(ClassName, ...) \ + ::logging::ClassName(__FILE__, __LINE__, ::logging::LOG_DFATAL, ##__VA_ARGS__) +#define COMPACT_GOOGLE_LOG_EX_DCHECK(ClassName, ...) \ + ::logging::ClassName(__FILE__, __LINE__, ::logging::LOG_DCHECK, ##__VA_ARGS__) + +#define COMPACT_GOOGLE_LOG_INFO COMPACT_GOOGLE_LOG_EX_INFO(LogMessage) +#define COMPACT_GOOGLE_LOG_WARNING COMPACT_GOOGLE_LOG_EX_WARNING(LogMessage) +#define COMPACT_GOOGLE_LOG_ERROR COMPACT_GOOGLE_LOG_EX_ERROR(LogMessage) +#define COMPACT_GOOGLE_LOG_FATAL COMPACT_GOOGLE_LOG_EX_FATAL(LogMessage) +#define COMPACT_GOOGLE_LOG_DFATAL COMPACT_GOOGLE_LOG_EX_DFATAL(LogMessage) +#define COMPACT_GOOGLE_LOG_DCHECK COMPACT_GOOGLE_LOG_EX_DCHECK(LogMessage) + +#if defined(OS_WIN) +// wingdi.h defines ERROR to be 0. When we call LOG(ERROR), it gets +// substituted with 0, and it expands to COMPACT_GOOGLE_LOG_0. To allow us +// to keep using this syntax, we define this macro to do the same thing +// as COMPACT_GOOGLE_LOG_ERROR, and also define ERROR the same way that +// the Windows SDK does for consistency. +#define ERROR 0 +#define COMPACT_GOOGLE_LOG_EX_0(ClassName, ...) \ + COMPACT_GOOGLE_LOG_EX_ERROR(ClassName, ##__VA_ARGS__) +#define COMPACT_GOOGLE_LOG_0 COMPACT_GOOGLE_LOG_ERROR +// Needed for LOG_IS_ON(ERROR). +const LogSeverity LOG_0 = LOG_ERROR; +#endif + +// As special cases, we can assume that LOG_IS_ON(FATAL) always holds. Also, +// LOG_IS_ON(DFATAL) always holds in debug mode. In particular, CHECK()s will +// always fire if they fail. +#define LOG_IS_ON(severity) \ + (::logging::ShouldCreateLogMessage(::logging::LOG_##severity)) + +// Helper macro which avoids evaluating the arguments to a stream if +// the condition doesn't hold. Condition is evaluated once and only once. +#define LAZY_STREAM(stream, condition) \ + !(condition) ? (void)0 : ::logging::LogMessageVoidify() & (stream) + +// We use the preprocessor's merging operator, "##", so that, e.g., +// LOG(INFO) becomes the token COMPACT_GOOGLE_LOG_INFO. There's some funny +// subtle difference between ostream member streaming functions (e.g., +// ostream::operator<<(int) and ostream non-member streaming functions +// (e.g., ::operator<<(ostream&, string&): it turns out that it's +// impossible to stream something like a string directly to an unnamed +// ostream. We employ a neat hack by calling the stream() member +// function of LogMessage which seems to avoid the problem. +#define LOG_STREAM(severity) COMPACT_GOOGLE_LOG_##severity.stream() + +#define LOG(severity) LAZY_STREAM(LOG_STREAM(severity), LOG_IS_ON(severity)) +#define LOG_IF(severity, condition) \ + LAZY_STREAM(LOG_STREAM(severity), LOG_IS_ON(severity) && (condition)) + +#define LOG_ASSERT(condition) \ + LOG_IF(FATAL, !(ANALYZER_ASSUME_TRUE(condition))) \ + << "Assert failed: " #condition ". " + +#if defined(OS_WIN) +#define PLOG_STREAM(severity) \ + COMPACT_GOOGLE_LOG_EX_##severity(Win32ErrorLogMessage, \ + ::logging::GetLastSystemErrorCode()) \ + .stream() +#elif defined(OS_POSIX) || defined(OS_FUCHSIA) +#define PLOG_STREAM(severity) \ + COMPACT_GOOGLE_LOG_EX_##severity(ErrnoLogMessage, \ + ::logging::GetLastSystemErrorCode()) \ + .stream() +#endif + +#define PLOG(severity) LAZY_STREAM(PLOG_STREAM(severity), LOG_IS_ON(severity)) + +#define PLOG_IF(severity, condition) \ + LAZY_STREAM(PLOG_STREAM(severity), LOG_IS_ON(severity) && (condition)) + +extern std::ostream* g_swallow_stream; + +// Note that g_swallow_stream is used instead of an arbitrary LOG() stream to +// avoid the creation of an object with a non-trivial destructor (LogMessage). +// On MSVC x86 (checked on 2015 Update 3), this causes a few additional +// pointless instructions to be emitted even at full optimization level, even +// though the : arm of the ternary operator is clearly never executed. Using a +// simpler object to be &'d with Voidify() avoids these extra instructions. +// Using a simpler POD object with a templated operator<< also works to avoid +// these instructions. However, this causes warnings on statically defined +// implementations of operator<<(std::ostream, ...) in some .cc files, because +// they become defined-but-unreferenced functions. A reinterpret_cast of 0 to an +// ostream* also is not suitable, because some compilers warn of undefined +// behavior. +#define EAT_STREAM_PARAMETERS \ + true ? (void)0 \ + : ::logging::LogMessageVoidify() & (*::logging::g_swallow_stream) + +// Captures the result of a CHECK_EQ (for example) and facilitates testing as a +// boolean. +class CheckOpResult { + public: + // |message| must be non-null if and only if the check failed. + CheckOpResult(std::string* message) : message_(message) {} + // Returns true if the check succeeded. + operator bool() const { return !message_; } + // Returns the message. + std::string* message() { return message_; } + + private: + std::string* message_; +}; + +// Crashes in the fastest possible way with no attempt at logging. +// There are different constraints to satisfy here, see http://crbug.com/664209 +// for more context: +// - The trap instructions, and hence the PC value at crash time, have to be +// distinct and not get folded into the same opcode by the compiler. +// On Linux/Android this is tricky because GCC still folds identical +// asm volatile blocks. The workaround is generating distinct opcodes for +// each CHECK using the __COUNTER__ macro. +// - The debug info for the trap instruction has to be attributed to the source +// line that has the CHECK(), to make crash reports actionable. This rules +// out the ability of using a inline function, at least as long as clang +// doesn't support attribute(artificial). +// - Failed CHECKs should produce a signal that is distinguishable from an +// invalid memory access, to improve the actionability of crash reports. +// - The compiler should treat the CHECK as no-return instructions, so that the +// trap code can be efficiently packed in the prologue of the function and +// doesn't interfere with the main execution flow. +// - When debugging, developers shouldn't be able to accidentally step over a +// CHECK. This is achieved by putting opcodes that will cause a non +// continuable exception after the actual trap instruction. +// - Don't cause too much binary bloat. +#if defined(COMPILER_GCC) + +#if defined(ARCH_CPU_X86_FAMILY) +// int 3 will generate a SIGTRAP. +#define TRAP_SEQUENCE() \ + asm volatile( \ + "int3; ud2; push %0;" ::"i"(static_cast<unsigned char>(__COUNTER__))) + +#elif defined(ARCH_CPU_ARMEL) +// bkpt will generate a SIGBUS when running on armv7 and a SIGTRAP when running +// as a 32 bit userspace app on arm64. There doesn't seem to be any way to +// cause a SIGTRAP from userspace without using a syscall (which would be a +// problem for sandboxing). +#define TRAP_SEQUENCE() \ + asm volatile("bkpt #0; udf %0;" ::"i"(__COUNTER__ % 256)) + +#elif defined(ARCH_CPU_ARM64) +// This will always generate a SIGTRAP on arm64. +#define TRAP_SEQUENCE() \ + asm volatile("brk #0; hlt %0;" ::"i"(__COUNTER__ % 65536)) + +#else +// Crash report accuracy will not be guaranteed on other architectures, but at +// least this will crash as expected. +#define TRAP_SEQUENCE() __builtin_trap() +#endif // ARCH_CPU_* + +// CHECK() and the trap sequence can be invoked from a constexpr function. +// This could make compilation fail on GCC, as it forbids directly using inline +// asm inside a constexpr function. However, it allows calling a lambda +// expression including the same asm. +// The side effect is that the top of the stacktrace will not point to the +// calling function, but to this anonymous lambda. This is still useful as the +// full name of the lambda will typically include the name of the function that +// calls CHECK() and the debugger will still break at the right line of code. +#if !defined(__clang__) +#define WRAPPED_TRAP_SEQUENCE() \ + do { \ + [] { TRAP_SEQUENCE(); }(); \ + } while (false) +#else +#define WRAPPED_TRAP_SEQUENCE() TRAP_SEQUENCE() +#endif + +#define IMMEDIATE_CRASH() \ + ({ \ + WRAPPED_TRAP_SEQUENCE(); \ + __builtin_unreachable(); \ + }) + +#elif defined(COMPILER_MSVC) + +// Clang is cleverer about coalescing int3s, so we need to add a unique-ish +// instruction following the __debugbreak() to have it emit distinct locations +// for CHECKs rather than collapsing them all together. It would be nice to use +// a short intrinsic to do this (and perhaps have only one implementation for +// both clang and MSVC), however clang-cl currently does not support intrinsics. +// On the flip side, MSVC x64 doesn't support inline asm. So, we have to have +// two implementations. Normally clang-cl's version will be 5 bytes (1 for +// `int3`, 2 for `ud2`, 2 for `push byte imm`, however, TODO(scottmg): +// https://crbug.com/694670 clang-cl doesn't currently support %'ing +// __COUNTER__, so eventually it will emit the dword form of push. +// TODO(scottmg): Reinvestigate a short sequence that will work on both +// compilers once clang supports more intrinsics. See https://crbug.com/693713. +#if defined(__clang__) +#define IMMEDIATE_CRASH() \ + ({ \ + {__asm int 3 __asm ud2 __asm push __COUNTER__}; \ + __builtin_unreachable(); \ + }) +#else +#define IMMEDIATE_CRASH() __debugbreak() +#endif // __clang__ + +#else +#error Port +#endif + +// CHECK dies with a fatal error if condition is not true. It is *not* +// controlled by NDEBUG, so the check will be executed regardless of +// compilation mode. +// +// We make sure CHECK et al. always evaluates their arguments, as +// doing CHECK(FunctionWithSideEffect()) is a common idiom. + +#if defined(OFFICIAL_BUILD) && defined(NDEBUG) + +// Make all CHECK functions discard their log strings to reduce code bloat, and +// improve performance, for official release builds. +// +// This is not calling BreakDebugger since this is called frequently, and +// calling an out-of-line function instead of a noreturn inline macro prevents +// compiler optimizations. +#define CHECK(condition) \ + UNLIKELY(!(condition)) ? IMMEDIATE_CRASH() : EAT_STREAM_PARAMETERS + +// PCHECK includes the system error code, which is useful for determining +// why the condition failed. In official builds, preserve only the error code +// message so that it is available in crash reports. The stringified +// condition and any additional stream parameters are dropped. +#define PCHECK(condition) \ + LAZY_STREAM(PLOG_STREAM(FATAL), UNLIKELY(!(condition))); \ + EAT_STREAM_PARAMETERS + +#define CHECK_OP(name, op, val1, val2) CHECK((val1)op(val2)) + +#else // !(OFFICIAL_BUILD && NDEBUG) + +#if defined(_PREFAST_) && defined(OS_WIN) +// Use __analysis_assume to tell the VC++ static analysis engine that +// assert conditions are true, to suppress warnings. The LAZY_STREAM +// parameter doesn't reference 'condition' in /analyze builds because +// this evaluation confuses /analyze. The !! before condition is because +// __analysis_assume gets confused on some conditions: +// http://randomascii.wordpress.com/2011/09/13/analyze-for-visual-studio-the-ugly-part-5/ + +#define CHECK(condition) \ + __analysis_assume(!!(condition)), LAZY_STREAM(LOG_STREAM(FATAL), false) \ + << "Check failed: " #condition ". " + +#define PCHECK(condition) \ + __analysis_assume(!!(condition)), LAZY_STREAM(PLOG_STREAM(FATAL), false) \ + << "Check failed: " #condition ". " + +#else // _PREFAST_ + +// Do as much work as possible out of line to reduce inline code size. +#define CHECK(condition) \ + LAZY_STREAM(::logging::LogMessage(__FILE__, __LINE__, #condition).stream(), \ + !ANALYZER_ASSUME_TRUE(condition)) + +#define PCHECK(condition) \ + LAZY_STREAM(PLOG_STREAM(FATAL), !ANALYZER_ASSUME_TRUE(condition)) \ + << "Check failed: " #condition ". " + +#endif // _PREFAST_ + +// Helper macro for binary operators. +// Don't use this macro directly in your code, use CHECK_EQ et al below. +// The 'switch' is used to prevent the 'else' from being ambiguous when the +// macro is used in an 'if' clause such as: +// if (a == 1) +// CHECK_EQ(2, a); +#define CHECK_OP(name, op, val1, val2) \ + switch (0) \ + case 0: \ + default: \ + if (::logging::CheckOpResult true_if_passed = \ + ::logging::Check##name##Impl((val1), (val2), \ + #val1 " " #op " " #val2)) \ + ; \ + else \ + ::logging::LogMessage(__FILE__, __LINE__, true_if_passed.message()) \ + .stream() + +#endif // !(OFFICIAL_BUILD && NDEBUG) + +// This formats a value for a failing CHECK_XX statement. Ordinarily, +// it uses the definition for operator<<, with a few special cases below. +template <typename T> +inline typename std::enable_if< + base::internal::SupportsOstreamOperator<const T&>::value && + !std::is_function<typename std::remove_pointer<T>::type>::value, + void>::type +MakeCheckOpValueString(std::ostream* os, const T& v) { + (*os) << v; +} + +// Provide an overload for functions and function pointers. Function pointers +// don't implicitly convert to void* but do implicitly convert to bool, so +// without this function pointers are always printed as 1 or 0. (MSVC isn't +// standards-conforming here and converts function pointers to regular +// pointers, so this is a no-op for MSVC.) +template <typename T> +inline typename std::enable_if< + std::is_function<typename std::remove_pointer<T>::type>::value, + void>::type +MakeCheckOpValueString(std::ostream* os, const T& v) { + (*os) << reinterpret_cast<const void*>(v); +} + +// We need overloads for enums that don't support operator<<. +// (i.e. scoped enums where no operator<< overload was declared). +template <typename T> +inline typename std::enable_if< + !base::internal::SupportsOstreamOperator<const T&>::value && + std::is_enum<T>::value, + void>::type +MakeCheckOpValueString(std::ostream* os, const T& v) { + (*os) << static_cast<typename std::underlying_type<T>::type>(v); +} + +// We need an explicit overload for std::nullptr_t. +void MakeCheckOpValueString(std::ostream* os, std::nullptr_t p); + +// Build the error message string. This is separate from the "Impl" +// function template because it is not performance critical and so can +// be out of line, while the "Impl" code should be inline. Caller +// takes ownership of the returned string. +template <class t1, class t2> +std::string* MakeCheckOpString(const t1& v1, const t2& v2, const char* names) { + std::ostringstream ss; + ss << names << " ("; + MakeCheckOpValueString(&ss, v1); + ss << " vs. "; + MakeCheckOpValueString(&ss, v2); + ss << ")"; + std::string* msg = new std::string(ss.str()); + return msg; +} + +// Commonly used instantiations of MakeCheckOpString<>. Explicitly instantiated +// in logging.cc. +extern template std::string* MakeCheckOpString<int, int>(const int&, + const int&, + const char* names); +extern template std::string* MakeCheckOpString<unsigned long, unsigned long>( + const unsigned long&, + const unsigned long&, + const char* names); +extern template std::string* MakeCheckOpString<unsigned long, unsigned int>( + const unsigned long&, + const unsigned int&, + const char* names); +extern template std::string* MakeCheckOpString<unsigned int, unsigned long>( + const unsigned int&, + const unsigned long&, + const char* names); +extern template std::string* MakeCheckOpString<std::string, std::string>( + const std::string&, + const std::string&, + const char* name); + +// Helper functions for CHECK_OP macro. +// The (int, int) specialization works around the issue that the compiler +// will not instantiate the template version of the function on values of +// unnamed enum type - see comment below. +// +// The checked condition is wrapped with ANALYZER_ASSUME_TRUE, which under +// static analysis builds, blocks analysis of the current path if the +// condition is false. +#define DEFINE_CHECK_OP_IMPL(name, op) \ + template <class t1, class t2> \ + inline std::string* Check##name##Impl(const t1& v1, const t2& v2, \ + const char* names) { \ + if (ANALYZER_ASSUME_TRUE(v1 op v2)) \ + return NULL; \ + else \ + return ::logging::MakeCheckOpString(v1, v2, names); \ + } \ + inline std::string* Check##name##Impl(int v1, int v2, const char* names) { \ + if (ANALYZER_ASSUME_TRUE(v1 op v2)) \ + return NULL; \ + else \ + return ::logging::MakeCheckOpString(v1, v2, names); \ + } +DEFINE_CHECK_OP_IMPL(EQ, ==) +DEFINE_CHECK_OP_IMPL(NE, !=) +DEFINE_CHECK_OP_IMPL(LE, <=) +DEFINE_CHECK_OP_IMPL(LT, <) +DEFINE_CHECK_OP_IMPL(GE, >=) +DEFINE_CHECK_OP_IMPL(GT, >) +#undef DEFINE_CHECK_OP_IMPL + +#define CHECK_EQ(val1, val2) CHECK_OP(EQ, ==, val1, val2) +#define CHECK_NE(val1, val2) CHECK_OP(NE, !=, val1, val2) +#define CHECK_LE(val1, val2) CHECK_OP(LE, <=, val1, val2) +#define CHECK_LT(val1, val2) CHECK_OP(LT, <, val1, val2) +#define CHECK_GE(val1, val2) CHECK_OP(GE, >=, val1, val2) +#define CHECK_GT(val1, val2) CHECK_OP(GT, >, val1, val2) + +#if defined(NDEBUG) && !defined(DCHECK_ALWAYS_ON) +#define DCHECK_IS_ON() 0 +#else +#define DCHECK_IS_ON() 1 +#endif + +// Definitions for DLOG et al. + +#if DCHECK_IS_ON() + +#define DLOG_IS_ON(severity) LOG_IS_ON(severity) +#define DLOG_IF(severity, condition) LOG_IF(severity, condition) +#define DLOG_ASSERT(condition) LOG_ASSERT(condition) +#define DPLOG_IF(severity, condition) PLOG_IF(severity, condition) + +#else // DCHECK_IS_ON() + +// If !DCHECK_IS_ON(), we want to avoid emitting any references to |condition| +// (which may reference a variable defined only if DCHECK_IS_ON()). +// Contrast this with DCHECK et al., which has different behavior. + +#define DLOG_IS_ON(severity) false +#define DLOG_IF(severity, condition) EAT_STREAM_PARAMETERS +#define DLOG_ASSERT(condition) EAT_STREAM_PARAMETERS +#define DPLOG_IF(severity, condition) EAT_STREAM_PARAMETERS + +#endif // DCHECK_IS_ON() + +#define DLOG(severity) LAZY_STREAM(LOG_STREAM(severity), DLOG_IS_ON(severity)) + +#define DPLOG(severity) LAZY_STREAM(PLOG_STREAM(severity), DLOG_IS_ON(severity)) + +// Definitions for DCHECK et al. + +#if DCHECK_IS_ON() + +#if DCHECK_IS_CONFIGURABLE +extern LogSeverity LOG_DCHECK; +#else +const LogSeverity LOG_DCHECK = LOG_FATAL; +#endif + +#else // DCHECK_IS_ON() + +// There may be users of LOG_DCHECK that are enabled independently +// of DCHECK_IS_ON(), so default to FATAL logging for those. +const LogSeverity LOG_DCHECK = LOG_FATAL; + +#endif // DCHECK_IS_ON() + +// DCHECK et al. make sure to reference |condition| regardless of +// whether DCHECKs are enabled; this is so that we don't get unused +// variable warnings if the only use of a variable is in a DCHECK. +// This behavior is different from DLOG_IF et al. +// +// Note that the definition of the DCHECK macros depends on whether or not +// DCHECK_IS_ON() is true. When DCHECK_IS_ON() is false, the macros use +// EAT_STREAM_PARAMETERS to avoid expressions that would create temporaries. + +#if defined(_PREFAST_) && defined(OS_WIN) +// See comments on the previous use of __analysis_assume. + +#define DCHECK(condition) \ + __analysis_assume(!!(condition)), LAZY_STREAM(LOG_STREAM(DCHECK), false) \ + << "Check failed: " #condition ". " + +#define DPCHECK(condition) \ + __analysis_assume(!!(condition)), LAZY_STREAM(PLOG_STREAM(DCHECK), false) \ + << "Check failed: " #condition ". " + +#else // !(defined(_PREFAST_) && defined(OS_WIN)) + +#if DCHECK_IS_ON() + +#define DCHECK(condition) \ + LAZY_STREAM(LOG_STREAM(DCHECK), !ANALYZER_ASSUME_TRUE(condition)) \ + << "Check failed: " #condition ". " +#define DPCHECK(condition) \ + LAZY_STREAM(PLOG_STREAM(DCHECK), !ANALYZER_ASSUME_TRUE(condition)) \ + << "Check failed: " #condition ". " + +#else // DCHECK_IS_ON() + +#define DCHECK(condition) EAT_STREAM_PARAMETERS << !(condition) +#define DPCHECK(condition) EAT_STREAM_PARAMETERS << !(condition) + +#endif // DCHECK_IS_ON() + +#endif // defined(_PREFAST_) && defined(OS_WIN) + +// Helper macro for binary operators. +// Don't use this macro directly in your code, use DCHECK_EQ et al below. +// The 'switch' is used to prevent the 'else' from being ambiguous when the +// macro is used in an 'if' clause such as: +// if (a == 1) +// DCHECK_EQ(2, a); +#if DCHECK_IS_ON() + +#define DCHECK_OP(name, op, val1, val2) \ + switch (0) \ + case 0: \ + default: \ + if (::logging::CheckOpResult true_if_passed = \ + DCHECK_IS_ON() ? ::logging::Check##name##Impl( \ + (val1), (val2), #val1 " " #op " " #val2) \ + : nullptr) \ + ; \ + else \ + ::logging::LogMessage(__FILE__, __LINE__, ::logging::LOG_DCHECK, \ + true_if_passed.message()) \ + .stream() + +#else // DCHECK_IS_ON() + +// When DCHECKs aren't enabled, DCHECK_OP still needs to reference operator<< +// overloads for |val1| and |val2| to avoid potential compiler warnings about +// unused functions. For the same reason, it also compares |val1| and |val2| +// using |op|. +// +// Note that the contract of DCHECK_EQ, etc is that arguments are only evaluated +// once. Even though |val1| and |val2| appear twice in this version of the macro +// expansion, this is OK, since the expression is never actually evaluated. +#define DCHECK_OP(name, op, val1, val2) \ + EAT_STREAM_PARAMETERS << (::logging::MakeCheckOpValueString( \ + ::logging::g_swallow_stream, val1), \ + ::logging::MakeCheckOpValueString( \ + ::logging::g_swallow_stream, val2), \ + (val1)op(val2)) + +#endif // DCHECK_IS_ON() + +// Equality/Inequality checks - compare two values, and log a +// LOG_DCHECK message including the two values when the result is not +// as expected. The values must have operator<<(ostream, ...) +// defined. +// +// You may append to the error message like so: +// DCHECK_NE(1, 2) << "The world must be ending!"; +// +// We are very careful to ensure that each argument is evaluated exactly +// once, and that anything which is legal to pass as a function argument is +// legal here. In particular, the arguments may be temporary expressions +// which will end up being destroyed at the end of the apparent statement, +// for example: +// DCHECK_EQ(string("abc")[1], 'b'); +// +// WARNING: These don't compile correctly if one of the arguments is a pointer +// and the other is NULL. In new code, prefer nullptr instead. To +// work around this for C++98, simply static_cast NULL to the type of the +// desired pointer. + +#define DCHECK_EQ(val1, val2) DCHECK_OP(EQ, ==, val1, val2) +#define DCHECK_NE(val1, val2) DCHECK_OP(NE, !=, val1, val2) +#define DCHECK_LE(val1, val2) DCHECK_OP(LE, <=, val1, val2) +#define DCHECK_LT(val1, val2) DCHECK_OP(LT, <, val1, val2) +#define DCHECK_GE(val1, val2) DCHECK_OP(GE, >=, val1, val2) +#define DCHECK_GT(val1, val2) DCHECK_OP(GT, >, val1, val2) + +#define NOTREACHED() DCHECK(false) + +// Redefine the standard assert to use our nice log files +#undef assert +#define assert(x) DLOG_ASSERT(x) + +// This class more or less represents a particular log message. You +// create an instance of LogMessage and then stream stuff to it. +// When you finish streaming to it, ~LogMessage is called and the +// full message gets streamed to the appropriate destination. +// +// You shouldn't actually use LogMessage's constructor to log things, +// though. You should use the LOG() macro (and variants thereof) +// above. +class LogMessage { + public: + // Used for LOG(severity). + LogMessage(const char* file, int line, LogSeverity severity); + + // Used for CHECK(). Implied severity = LOG_FATAL. + LogMessage(const char* file, int line, const char* condition); + + // Used for CHECK_EQ(), etc. Takes ownership of the given string. + // Implied severity = LOG_FATAL. + LogMessage(const char* file, int line, std::string* result); + + // Used for DCHECK_EQ(), etc. Takes ownership of the given string. + LogMessage(const char* file, + int line, + LogSeverity severity, + std::string* result); + + ~LogMessage(); + + std::ostream& stream() { return stream_; } + + LogSeverity severity() { return severity_; } + std::string str() { return stream_.str(); } + + private: + void Init(const char* file, int line); + + LogSeverity severity_; + std::ostringstream stream_; + size_t message_start_; // Offset of the start of the message (past prefix + // info). + +#if defined(OS_WIN) + // Stores the current value of GetLastError in the constructor and restores + // it in the destructor by calling SetLastError. + // This is useful since the LogMessage class uses a lot of Win32 calls + // that will lose the value of GLE and the code that called the log function + // will have lost the thread error value when the log call returns. + class SaveLastError { + public: + SaveLastError(); + ~SaveLastError(); + + unsigned long get_error() const { return last_error_; } + + protected: + unsigned long last_error_; + }; + + SaveLastError last_error_; +#endif + + DISALLOW_COPY_AND_ASSIGN(LogMessage); +}; + +// This class is used to explicitly ignore values in the conditional +// logging macros. This avoids compiler warnings like "value computed +// is not used" and "statement has no effect". +class LogMessageVoidify { + public: + LogMessageVoidify() = default; + // This has to be an operator with a precedence lower than << but + // higher than ?: + void operator&(std::ostream&) {} +}; + +#if defined(OS_WIN) +typedef unsigned long SystemErrorCode; +#elif defined(OS_POSIX) || defined(OS_FUCHSIA) +typedef int SystemErrorCode; +#endif + +// Alias for ::GetLastError() on Windows and errno on POSIX. Avoids having to +// pull in windows.h just for GetLastError() and DWORD. +SystemErrorCode GetLastSystemErrorCode(); +std::string SystemErrorCodeToString(SystemErrorCode error_code); + +#if defined(OS_WIN) +// Appends a formatted system message of the GetLastError() type. +class Win32ErrorLogMessage { + public: + Win32ErrorLogMessage(const char* file, + int line, + LogSeverity severity, + SystemErrorCode err); + + // Appends the error message before destructing the encapsulated class. + ~Win32ErrorLogMessage(); + + std::ostream& stream() { return log_message_.stream(); } + + private: + SystemErrorCode err_; + LogMessage log_message_; + + DISALLOW_COPY_AND_ASSIGN(Win32ErrorLogMessage); +}; +#elif defined(OS_POSIX) || defined(OS_FUCHSIA) +// Appends a formatted system message of the errno type +class ErrnoLogMessage { + public: + ErrnoLogMessage(const char* file, + int line, + LogSeverity severity, + SystemErrorCode err); + + // Appends the error message before destructing the encapsulated class. + ~ErrnoLogMessage(); + + std::ostream& stream() { return log_message_.stream(); } + + private: + SystemErrorCode err_; + LogMessage log_message_; + + DISALLOW_COPY_AND_ASSIGN(ErrnoLogMessage); +}; +#endif // OS_WIN + +// Closes the log file explicitly if open. +// NOTE: Since the log file is opened as necessary by the action of logging +// statements, there's no guarantee that it will stay closed +// after this call. +void CloseLogFile(); + +// Async signal safe logging mechanism. +void RawLog(int level, const char* message); + +#define RAW_LOG(level, message) \ + ::logging::RawLog(::logging::LOG_##level, message) + +#define RAW_CHECK(condition) \ + do { \ + if (!(condition)) \ + ::logging::RawLog(::logging::LOG_FATAL, \ + "Check failed: " #condition "\n"); \ + } while (0) + +#if defined(OS_WIN) +// Returns true if logging to file is enabled. +bool IsLoggingToFileEnabled(); + +// Returns the default log file path. +std::u16string GetLogFileFullPath(); +#endif + +} // namespace logging + +// The NOTIMPLEMENTED() macro annotates codepaths which have not been +// implemented yet. If output spam is a serious concern, +// NOTIMPLEMENTED_LOG_ONCE can be used. + +#if defined(COMPILER_GCC) +// On Linux, with GCC, we can use __PRETTY_FUNCTION__ to get the demangled name +// of the current function in the NOTIMPLEMENTED message. +#define NOTIMPLEMENTED_MSG "Not implemented reached in " << __PRETTY_FUNCTION__ +#else +#define NOTIMPLEMENTED_MSG "NOT IMPLEMENTED" +#endif + +#if defined(OS_ANDROID) && defined(OFFICIAL_BUILD) +#define NOTIMPLEMENTED() EAT_STREAM_PARAMETERS +#define NOTIMPLEMENTED_LOG_ONCE() EAT_STREAM_PARAMETERS +#else +#define NOTIMPLEMENTED() LOG(ERROR) << NOTIMPLEMENTED_MSG +#define NOTIMPLEMENTED_LOG_ONCE() \ + do { \ + static bool logged_once = false; \ + LOG_IF(ERROR, !logged_once) << NOTIMPLEMENTED_MSG; \ + logged_once = true; \ + } while (0); \ + EAT_STREAM_PARAMETERS +#endif + +#endif // BASE_LOGGING_H_ |