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 <string> 9 10 #include "base/base_export.h" 11 #include "base/basictypes.h" 12 13 namespace tracked_objects { 14 15 // Location provides basic info where of an object was constructed, or was 16 // significantly brought to life. 17 class BASE_EXPORT Location { 18 public: 19 // Constructor should be called with a long-lived char*, such as __FILE__. 20 // It assumes the provided value will persist as a global constant, and it 21 // will not make a copy of it. 22 Location(const char* function_name, 23 const char* file_name, 24 int line_number, 25 const void* program_counter); 26 27 // Provide a default constructor for easy of debugging. 28 Location(); 29 30 // Comparison operator for insertion into a std::map<> hash tables. 31 // All we need is *some* (any) hashing distinction. Strings should already 32 // be unique, so we don't bother with strcmp or such. 33 // Use line number as the primary key (because it is fast, and usually gets us 34 // a difference), and then pointers as secondary keys (just to get some 35 // distinctions). 36 bool operator < (const Location& other) const { 37 if (line_number_ != other.line_number_) 38 return line_number_ < other.line_number_; 39 if (file_name_ != other.file_name_) 40 return file_name_ < other.file_name_; 41 return function_name_ < other.function_name_; 42 } 43 function_name()44 const char* function_name() const { return function_name_; } file_name()45 const char* file_name() const { return file_name_; } line_number()46 int line_number() const { return line_number_; } program_counter()47 const void* program_counter() const { return program_counter_; } 48 49 std::string ToString() const; 50 51 // Translate the some of the state in this instance into a human readable 52 // string with HTML characters in the function names escaped, and append that 53 // string to |output|. Inclusion of the file_name_ and function_name_ are 54 // optional, and controlled by the boolean arguments. 55 void Write(bool display_filename, bool display_function_name, 56 std::string* output) const; 57 58 // Write function_name_ in HTML with '<' and '>' properly encoded. 59 void WriteFunctionName(std::string* output) const; 60 61 private: 62 const char* function_name_; 63 const char* file_name_; 64 int line_number_; 65 const void* program_counter_; 66 }; 67 68 // A "snapshotted" representation of the Location class that can safely be 69 // passed across process boundaries. 70 struct BASE_EXPORT LocationSnapshot { 71 // The default constructor is exposed to support the IPC serialization macros. 72 LocationSnapshot(); 73 explicit LocationSnapshot(const tracked_objects::Location& location); 74 ~LocationSnapshot(); 75 76 std::string file_name; 77 std::string function_name; 78 int line_number; 79 }; 80 81 BASE_EXPORT const void* GetProgramCounter(); 82 83 // Define a macro to record the current source location. 84 #define FROM_HERE FROM_HERE_WITH_EXPLICIT_FUNCTION(__FUNCTION__) 85 86 #define FROM_HERE_WITH_EXPLICIT_FUNCTION(function_name) \ 87 ::tracked_objects::Location(function_name, \ 88 __FILE__, \ 89 __LINE__, \ 90 ::tracked_objects::GetProgramCounter()) 91 92 } // namespace tracked_objects 93 94 #endif // BASE_LOCATION_H_ 95