1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 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_LOCATION_H_ 6 #define BASE_LOCATION_H_ 7 8 #include <stddef.h> 9 10 #include <cassert> 11 #include <string> 12 13 #include "base/base_export.h" 14 #include "base/debug/debugging_buildflags.h" 15 #include "base/hash.h" 16 17 namespace base { 18 19 // Location provides basic info where of an object was constructed, or was 20 // significantly brought to life. 21 class BASE_EXPORT Location { 22 public: 23 Location(); 24 Location(const Location& other); 25 26 // Only initializes the file name and program counter, the source information 27 // will be null for the strings, and -1 for the line number. 28 // TODO(http://crbug.com/760702) remove file name from this constructor. 29 Location(const char* file_name, const void* program_counter); 30 31 // Constructor should be called with a long-lived char*, such as __FILE__. 32 // It assumes the provided value will persist as a global constant, and it 33 // will not make a copy of it. 34 Location(const char* function_name, 35 const char* file_name, 36 int line_number, 37 const void* program_counter); 38 39 // Comparator for hash map insertion. The program counter should uniquely 40 // identify a location. 41 bool operator==(const Location& other) const { 42 return program_counter_ == other.program_counter_; 43 } 44 45 // Returns true if there is source code location info. If this is false, 46 // the Location object only contains a program counter or is 47 // default-initialized (the program counter is also null). has_source_info()48 bool has_source_info() const { return function_name_ && file_name_; } 49 50 // Will be nullptr for default initialized Location objects and when source 51 // names are disabled. function_name()52 const char* function_name() const { return function_name_; } 53 54 // Will be nullptr for default initialized Location objects and when source 55 // names are disabled. file_name()56 const char* file_name() const { return file_name_; } 57 58 // Will be -1 for default initialized Location objects and when source names 59 // are disabled. line_number()60 int line_number() const { return line_number_; } 61 62 // The address of the code generating this Location object. Should always be 63 // valid except for default initialized Location objects, which will be 64 // nullptr. program_counter()65 const void* program_counter() const { return program_counter_; } 66 67 // Converts to the most user-readable form possible. If function and filename 68 // are not available, this will return "pc:<hex address>". 69 std::string ToString() const; 70 71 static Location CreateFromHere(const char* file_name); 72 static Location CreateFromHere(const char* function_name, 73 const char* file_name, 74 int line_number); 75 76 private: 77 const char* function_name_ = nullptr; 78 const char* file_name_ = nullptr; 79 int line_number_ = -1; 80 const void* program_counter_ = nullptr; 81 }; 82 83 BASE_EXPORT const void* GetProgramCounter(); 84 85 // The macros defined here will expand to the current function. 86 #if BUILDFLAG(ENABLE_LOCATION_SOURCE) 87 88 // Full source information should be included. 89 #define FROM_HERE FROM_HERE_WITH_EXPLICIT_FUNCTION(__func__) 90 #define FROM_HERE_WITH_EXPLICIT_FUNCTION(function_name) \ 91 ::base::Location::CreateFromHere(function_name, __FILE__, __LINE__) 92 93 #else 94 95 // TODO(http://crbug.com/760702) remove the __FILE__ argument from these calls. 96 #define FROM_HERE ::base::Location::CreateFromHere(__FILE__) 97 #define FROM_HERE_WITH_EXPLICIT_FUNCTION(function_name) \ 98 ::base::Location::CreateFromHere(function_name, __FILE__, -1) 99 100 #endif 101 102 } // namespace base 103 104 namespace std { 105 106 // Specialization for using Location in hash tables. 107 template <> 108 struct hash<::base::Location> { 109 std::size_t operator()(const ::base::Location& loc) const { 110 const void* program_counter = loc.program_counter(); 111 return base::Hash(&program_counter, sizeof(void*)); 112 } 113 }; 114 115 } // namespace std 116 117 #endif // BASE_LOCATION_H_ 118