1 // Protocol Buffers - Google's data interchange format 2 // Copyright 2008 Google Inc. All rights reserved. 3 // https://developers.google.com/protocol-buffers/ 4 // 5 // Redistribution and use in source and binary forms, with or without 6 // modification, are permitted provided that the following conditions are 7 // met: 8 // 9 // * Redistributions of source code must retain the above copyright 10 // notice, this list of conditions and the following disclaimer. 11 // * Redistributions in binary form must reproduce the above 12 // copyright notice, this list of conditions and the following disclaimer 13 // in the documentation and/or other materials provided with the 14 // distribution. 15 // * Neither the name of Google Inc. nor the names of its 16 // contributors may be used to endorse or promote products derived from 17 // this software without specific prior written permission. 18 // 19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 31 // Author: kenton@google.com (Kenton Varda) 32 // Based on original Protocol Buffers design by 33 // Sanjay Ghemawat, Jeff Dean, and others. 34 35 #ifndef GOOGLE_PROTOBUF_COMPILER_CPP_FIELD_H__ 36 #define GOOGLE_PROTOBUF_COMPILER_CPP_FIELD_H__ 37 38 #include <map> 39 #include <memory> 40 #ifndef _SHARED_PTR_H 41 #include <google/protobuf/stubs/shared_ptr.h> 42 #endif 43 #include <string> 44 45 #include <google/protobuf/descriptor.h> 46 #include <google/protobuf/compiler/cpp/cpp_options.h> 47 48 namespace google { 49 namespace protobuf { 50 namespace io { 51 class Printer; // printer.h 52 } 53 } 54 55 namespace protobuf { 56 namespace compiler { 57 namespace cpp { 58 59 // Helper function: set variables in the map that are the same for all 60 // field code generators. 61 // ['name', 'index', 'number', 'classname', 'declared_type', 'tag_size', 62 // 'deprecation']. 63 void SetCommonFieldVariables(const FieldDescriptor* descriptor, 64 map<string, string>* variables, 65 const Options& options); 66 67 void SetCommonOneofFieldVariables(const FieldDescriptor* descriptor, 68 map<string, string>* variables); 69 70 class FieldGenerator { 71 public: FieldGenerator(const Options & options)72 explicit FieldGenerator(const Options& options) : options_(options) {} 73 virtual ~FieldGenerator(); 74 75 // Generate lines of code declaring members fields of the message class 76 // needed to represent this field. These are placed inside the message 77 // class. 78 virtual void GeneratePrivateMembers(io::Printer* printer) const = 0; 79 80 // Generate static default variable for this field. These are placed inside 81 // the message class. Most field types don't need this, so the default 82 // implementation is empty. GenerateStaticMembers(io::Printer *)83 virtual void GenerateStaticMembers(io::Printer* /*printer*/) const {} 84 85 // Generate prototypes for accessors that will manipulate imported 86 // messages inline. These are for .proto.h headers. 87 // 88 // In .proto.h mode, the headers of imports are not #included. However, 89 // functions that manipulate the imported message types need access to 90 // the class definition of the imported message, meaning that the headers 91 // must be #included. To get around this, functions that manipulate 92 // imported message objects are defined as dependent functions in a base 93 // template class. By making them dependent template functions, the 94 // function templates will not be instantiated until they are called, so 95 // we can defer to those translation units to #include the necessary 96 // generated headers. 97 // 98 // See: 99 // http://en.cppreference.com/w/cpp/language/class_template#Implicit_instantiation 100 // 101 // Most field types don't need this, so the default implementation is empty. GenerateDependentAccessorDeclarations(io::Printer * printer)102 virtual void GenerateDependentAccessorDeclarations( 103 io::Printer* printer) const {} 104 105 // Generate prototypes for all of the accessor functions related to this 106 // field. These are placed inside the class definition. 107 virtual void GenerateAccessorDeclarations(io::Printer* printer) const = 0; 108 109 // Generate inline definitions of depenent accessor functions for this field. 110 // These are placed inside the header after all class definitions. GenerateDependentInlineAccessorDefinitions(io::Printer * printer)111 virtual void GenerateDependentInlineAccessorDefinitions( 112 io::Printer* printer) const {} 113 114 // Generate inline definitions of accessor functions for this field. 115 // These are placed inside the header after all class definitions. 116 // In non-.proto.h mode, this generates dependent accessor functions as well. 117 virtual void GenerateInlineAccessorDefinitions( 118 io::Printer* printer, bool is_inline) const = 0; 119 120 // Generate definitions of accessors that aren't inlined. These are 121 // placed somewhere in the .cc file. 122 // Most field types don't need this, so the default implementation is empty. GenerateNonInlineAccessorDefinitions(io::Printer *)123 virtual void GenerateNonInlineAccessorDefinitions( 124 io::Printer* /*printer*/) const {} 125 126 // Generate lines of code (statements, not declarations) which clear the 127 // field. This is used to define the clear_$name$() method as well as 128 // the Clear() method for the whole message. 129 virtual void GenerateClearingCode(io::Printer* printer) const = 0; 130 131 // Generate lines of code (statements, not declarations) which merges the 132 // contents of the field from the current message to the target message, 133 // which is stored in the generated code variable "from". 134 // This is used to fill in the MergeFrom method for the whole message. 135 // Details of this usage can be found in message.cc under the 136 // GenerateMergeFrom method. 137 virtual void GenerateMergingCode(io::Printer* printer) const = 0; 138 139 // Generate lines of code (statements, not declarations) which swaps 140 // this field and the corresponding field of another message, which 141 // is stored in the generated code variable "other". This is used to 142 // define the Swap method. Details of usage can be found in 143 // message.cc under the GenerateSwap method. 144 virtual void GenerateSwappingCode(io::Printer* printer) const = 0; 145 146 // Generate initialization code for private members declared by 147 // GeneratePrivateMembers(). These go into the message class's SharedCtor() 148 // method, invoked by each of the generated constructors. 149 virtual void GenerateConstructorCode(io::Printer* printer) const = 0; 150 151 // Generate any code that needs to go in the class's SharedDtor() method, 152 // invoked by the destructor. 153 // Most field types don't need this, so the default implementation is empty. GenerateDestructorCode(io::Printer *)154 virtual void GenerateDestructorCode(io::Printer* /*printer*/) const {} 155 156 // Generate a manual destructor invocation for use when the message is on an 157 // arena. The code that this method generates will be executed inside a 158 // shared-for-the-whole-message-class method registered with OwnDestructor(). 159 // The method should return |true| if it generated any code that requires a 160 // call; this allows the message generator to eliminate the OwnDestructor() 161 // registration if no fields require it. GenerateArenaDestructorCode(io::Printer * printer)162 virtual bool GenerateArenaDestructorCode(io::Printer* printer) const { 163 return false; 164 } 165 166 // Generate code that allocates the fields's default instance. GenerateDefaultInstanceAllocator(io::Printer *)167 virtual void GenerateDefaultInstanceAllocator(io::Printer* /*printer*/) 168 const {} 169 170 // Generate code that should be run when ShutdownProtobufLibrary() is called, 171 // to delete all dynamically-allocated objects. GenerateShutdownCode(io::Printer *)172 virtual void GenerateShutdownCode(io::Printer* /*printer*/) const {} 173 174 // Generate lines to decode this field, which will be placed inside the 175 // message's MergeFromCodedStream() method. 176 virtual void GenerateMergeFromCodedStream(io::Printer* printer) const = 0; 177 178 // Generate lines to decode this field from a packed value, which will be 179 // placed inside the message's MergeFromCodedStream() method. 180 virtual void GenerateMergeFromCodedStreamWithPacking(io::Printer* printer) 181 const; 182 183 // Generate lines to serialize this field, which are placed within the 184 // message's SerializeWithCachedSizes() method. 185 virtual void GenerateSerializeWithCachedSizes(io::Printer* printer) const = 0; 186 187 // Generate lines to serialize this field directly to the array "target", 188 // which are placed within the message's SerializeWithCachedSizesToArray() 189 // method. This must also advance "target" past the written bytes. 190 virtual void GenerateSerializeWithCachedSizesToArray( 191 io::Printer* printer) const = 0; 192 193 // Generate lines to compute the serialized size of this field, which 194 // are placed in the message's ByteSize() method. 195 virtual void GenerateByteSize(io::Printer* printer) const = 0; 196 197 protected: 198 const Options& options_; 199 200 private: 201 GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(FieldGenerator); 202 }; 203 204 // Convenience class which constructs FieldGenerators for a Descriptor. 205 class FieldGeneratorMap { 206 public: 207 FieldGeneratorMap(const Descriptor* descriptor, const Options& options); 208 ~FieldGeneratorMap(); 209 210 const FieldGenerator& get(const FieldDescriptor* field) const; 211 212 private: 213 const Descriptor* descriptor_; 214 const Options& options_; 215 google::protobuf::scoped_array<google::protobuf::scoped_ptr<FieldGenerator> > field_generators_; 216 217 static FieldGenerator* MakeGenerator(const FieldDescriptor* field, 218 const Options& options); 219 220 GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(FieldGeneratorMap); 221 }; 222 223 224 } // namespace cpp 225 } // namespace compiler 226 } // namespace protobuf 227 228 } // namespace google 229 #endif // GOOGLE_PROTOBUF_COMPILER_CPP_FIELD_H__ 230