// 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_LOCATION_H_ #define BASE_LOCATION_H_ #include #include "base/base_export.h" #include "base/debug/debugging_buildflags.h" #include "base/memory/raw_ptr_exclusion.h" #include "base/trace_event/base_tracing_forward.h" #include "build/build_config.h" namespace base { #if defined(__clang__) // Clang allows detection of these builtins. #define SUPPORTS_LOCATION_BUILTINS \ (__has_builtin(__builtin_FUNCTION) && __has_builtin(__builtin_FILE) && \ __has_builtin(__builtin_LINE)) #elif defined(COMPILER_GCC) && __GNUC__ >= 7 // GCC has supported these for a long time, but they point at the function // declaration in the case of default arguments, rather than at the call site. #define SUPPORTS_LOCATION_BUILTINS 1 #else #define SUPPORTS_LOCATION_BUILTINS 0 #endif // Location provides basic info where of an object was constructed, or was // significantly brought to life. class BASE_EXPORT Location { public: Location(); Location(const Location& other); Location(Location&& other) noexcept; Location& operator=(const Location& other); // Only initializes the file name and program counter, the source information // will be null for the strings, and -1 for the line number. // TODO(http://crbug.com/760702) remove file name from this constructor. Location(const char* file_name, const void* program_counter); // Constructor should be called with a long-lived char*, such as __FILE__. // It assumes the provided value will persist as a global constant, and it // will not make a copy of it. Location(const char* function_name, const char* file_name, int line_number, const void* program_counter); // Comparator for testing. The program counter should uniquely // identify a location. bool operator==(const Location& other) const { return program_counter_ == other.program_counter_; } // Comparator is necessary to use location object within an ordered container // type (eg. std::map). bool operator<(const Location& other) const { return program_counter_ < other.program_counter_; } // Returns true if there is source code location info. If this is false, // the Location object only contains a program counter or is // default-initialized (the program counter is also null). bool has_source_info() const { return function_name_ && file_name_; } // Will be nullptr for default initialized Location objects and when source // names are disabled. const char* function_name() const { return function_name_; } // Will be nullptr for default initialized Location objects and when source // names are disabled. const char* file_name() const { return file_name_; } // Will be -1 for default initialized Location objects and when source names // are disabled. int line_number() const { return line_number_; } // The address of the code generating this Location object. Should always be // valid except for default initialized Location objects, which will be // nullptr. const void* program_counter() const { return program_counter_; } // Converts to the most user-readable form possible. If function and filename // are not available, this will return "pc:". std::string ToString() const; // Write a representation of this object into a trace. void WriteIntoTrace(perfetto::TracedValue context) const; #if !BUILDFLAG(FROM_HERE_USES_LOCATION_BUILTINS) #if !BUILDFLAG(ENABLE_LOCATION_SOURCE) static Location CreateFromHere(const char* file_name); #else static Location CreateFromHere(const char* function_name, const char* file_name, int line_number); #endif #endif #if SUPPORTS_LOCATION_BUILTINS && BUILDFLAG(ENABLE_LOCATION_SOURCE) static Location Current(const char* function_name = __builtin_FUNCTION(), const char* file_name = __builtin_FILE(), int line_number = __builtin_LINE()); #elif SUPPORTS_LOCATION_BUILTINS static Location Current(const char* file_name = __builtin_FILE()); #else static Location Current(); #endif private: const char* function_name_ = nullptr; const char* file_name_ = nullptr; int line_number_ = -1; // `program_counter_` is not a raw_ptr<...> for performance reasons (based on // analysis of sampling profiler data and tab_search:top100:2020). RAW_PTR_EXCLUSION const void* program_counter_ = nullptr; }; BASE_EXPORT const void* GetProgramCounter(); #if BUILDFLAG(FROM_HERE_USES_LOCATION_BUILTINS) #define FROM_HERE ::base::Location::Current() // The macros defined here will expand to the current function. #elif BUILDFLAG(ENABLE_LOCATION_SOURCE) // Full source information should be included. #define FROM_HERE ::base::Location::CreateFromHere(__func__, __FILE__, __LINE__) #else // TODO(http://crbug.com/760702) remove the __FILE__ argument from these calls. #define FROM_HERE ::base::Location::CreateFromHere(__FILE__) #endif } // namespace base #endif // BASE_LOCATION_H_