| // Copyright 2012 The Chromium Authors |
| // 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 <compare> |
| #include <string> |
| |
| #include "base/base_export.h" |
| #include "base/memory/raw_ptr_exclusion.h" |
| #include "base/trace_event/base_tracing_forward.h" |
| #include "build/build_config.h" |
| |
| namespace base { |
| |
| // 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); |
| |
| static Location CreateForTesting(const char* function_name, |
| const char* file_name, |
| int line_number, |
| const void* program_counter) { |
| return Location(function_name, file_name, line_number, program_counter); |
| } |
| |
| // Comparator for testing. The program counter should uniquely |
| // identify a location. |
| friend bool operator==(const Location& lhs, const Location& rhs) { |
| return lhs.program_counter_ == rhs.program_counter_; |
| } |
| |
| // The program counter should uniquely identify a location. There is no |
| // guarantee that a program counter corresponds to unique function/file/line |
| // values, based on how it's constructed, and therefore equivalent locations |
| // could be distinguishable. |
| friend std::weak_ordering operator<=>(const Location& lhs, |
| const Location& rhs) { |
| return lhs.program_counter_ <=> rhs.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:<hex address>". |
| std::string ToString() const; |
| |
| // Write a representation of this object into a trace. |
| void WriteIntoTrace(perfetto::TracedValue context) const; |
| |
| static Location Current(const char* function_name = __builtin_FUNCTION(), |
| const char* file_name = __builtin_FILE(), |
| int line_number = __builtin_LINE()); |
| |
| private: |
| // 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); |
| |
| 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(); |
| |
| #define FROM_HERE ::base::Location::Current() |
| |
| } // namespace base |
| |
| #endif // BASE_LOCATION_H_ |