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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 #include <string>
41 
42 #include <google/protobuf/compiler/cpp/cpp_helpers.h>
43 #include <google/protobuf/compiler/cpp/cpp_options.h>
44 #include <google/protobuf/descriptor.h>
45 
46 namespace google {
47 namespace protobuf {
48 namespace io {
49 class Printer;  // printer.h
50 }
51 }  // namespace protobuf
52 }  // namespace google
53 
54 namespace google {
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                              std::map<std::string, std::string>* variables,
65                              const Options& options);
66 
67 void SetCommonOneofFieldVariables(
68     const FieldDescriptor* descriptor,
69     std::map<std::string, std::string>* variables);
70 
71 class FieldGenerator {
72  public:
FieldGenerator(const FieldDescriptor * descriptor,const Options & options)73   explicit FieldGenerator(const FieldDescriptor* descriptor,
74                           const Options& options)
75       : descriptor_(descriptor), options_(options) {}
76   virtual ~FieldGenerator();
77 
78   // Generate lines of code declaring members fields of the message class
79   // needed to represent this field.  These are placed inside the message
80   // class.
81   virtual void GeneratePrivateMembers(io::Printer* printer) const = 0;
82 
83   // Generate static default variable for this field. These are placed inside
84   // the message class. Most field types don't need this, so the default
85   // implementation is empty.
GenerateStaticMembers(io::Printer *)86   virtual void GenerateStaticMembers(io::Printer* /*printer*/) const {}
87 
88   // Generate prototypes for all of the accessor functions related to this
89   // field.  These are placed inside the class definition.
90   virtual void GenerateAccessorDeclarations(io::Printer* printer) const = 0;
91 
92   // Generate inline definitions of accessor functions for this field.
93   // These are placed inside the header after all class definitions.
94   virtual void GenerateInlineAccessorDefinitions(
95       io::Printer* printer) const = 0;
96 
97   // Generate definitions of accessors that aren't inlined.  These are
98   // placed somewhere in the .cc file.
99   // Most field types don't need this, so the default implementation is empty.
GenerateNonInlineAccessorDefinitions(io::Printer *)100   virtual void GenerateNonInlineAccessorDefinitions(
101       io::Printer* /*printer*/) const {}
102 
103   // Generate declarations of accessors that are for internal purposes only.
104   // Most field types don't need this, so the default implementation is empty.
GenerateInternalAccessorDefinitions(io::Printer *)105   virtual void GenerateInternalAccessorDefinitions(
106       io::Printer* /*printer*/) const {}
107 
108   // Generate definitions of accessors that are for internal purposes only.
109   // Most field types don't need this, so the default implementation is empty.
GenerateInternalAccessorDeclarations(io::Printer *)110   virtual void GenerateInternalAccessorDeclarations(
111       io::Printer* /*printer*/) const {}
112 
113   // Generate lines of code (statements, not declarations) which clear the
114   // field.  This is used to define the clear_$name$() method
115   virtual void GenerateClearingCode(io::Printer* printer) const = 0;
116 
117   // Generate lines of code (statements, not declarations) which clear the
118   // field as part of the Clear() method for the whole message.  For message
119   // types which have field presence bits, MessageGenerator::GenerateClear
120   // will have already checked the presence bits.
121   //
122   // Since most field types can re-use GenerateClearingCode, this method is
123   // not pure virtual.
GenerateMessageClearingCode(io::Printer * printer)124   virtual void GenerateMessageClearingCode(io::Printer* printer) const {
125     GenerateClearingCode(printer);
126   }
127 
128   // Generate lines of code (statements, not declarations) which merges the
129   // contents of the field from the current message to the target message,
130   // which is stored in the generated code variable "from".
131   // This is used to fill in the MergeFrom method for the whole message.
132   // Details of this usage can be found in message.cc under the
133   // GenerateMergeFrom method.
134   virtual void GenerateMergingCode(io::Printer* printer) const = 0;
135 
136   // Generates a copy constructor
137   virtual void GenerateCopyConstructorCode(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
159   // OwnDestructor(). The method should return |true| if it generated any code
160   // that requires a call; this allows the message generator to eliminate the
161   // OwnDestructor() 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(
168       io::Printer* /*printer*/) const {}
169 
170   // Generate lines to decode this field, which will be placed inside the
171   // message's MergeFromCodedStream() method.
172   virtual void GenerateMergeFromCodedStream(io::Printer* printer) const = 0;
173 
174   // Returns true if this field's "MergeFromCodedStream" code needs the arena
175   // to be defined as a variable.
MergeFromCodedStreamNeedsArena()176   virtual bool MergeFromCodedStreamNeedsArena() const { return false; }
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(
181       io::Printer* printer) 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   // Any tags about field layout decisions (such as inlining) to embed in the
198   // offset.
CalculateFieldTag()199   virtual uint32 CalculateFieldTag() const { return 0; }
IsInlined()200   virtual bool IsInlined() const { return false; }
201 
202   void SetHasBitIndex(int32 has_bit_index);
203 
204  protected:
205   const FieldDescriptor* descriptor_;
206   const Options& options_;
207   std::map<std::string, std::string> variables_;
208 
209  private:
210   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(FieldGenerator);
211 };
212 
213 // Convenience class which constructs FieldGenerators for a Descriptor.
214 class FieldGeneratorMap {
215  public:
216   FieldGeneratorMap(const Descriptor* descriptor, const Options& options,
217                     MessageSCCAnalyzer* scc_analyzer);
218   ~FieldGeneratorMap();
219 
220   const FieldGenerator& get(const FieldDescriptor* field) const;
221 
SetHasBitIndices(const std::vector<int> & has_bit_indices_)222   void SetHasBitIndices(const std::vector<int>& has_bit_indices_) {
223     for (int i = 0; i < descriptor_->field_count(); ++i) {
224       field_generators_[i]->SetHasBitIndex(has_bit_indices_[i]);
225     }
226   }
227 
228  private:
229   const Descriptor* descriptor_;
230   std::vector<std::unique_ptr<FieldGenerator>> field_generators_;
231 
232   static FieldGenerator* MakeGoogleInternalGenerator(
233       const FieldDescriptor* field, const Options& options,
234       MessageSCCAnalyzer* scc_analyzer);
235   static FieldGenerator* MakeGenerator(const FieldDescriptor* field,
236                                        const Options& options,
237                                        MessageSCCAnalyzer* scc_analyzer);
238 
239   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(FieldGeneratorMap);
240 };
241 
242 }  // namespace cpp
243 }  // namespace compiler
244 }  // namespace protobuf
245 }  // namespace google
246 
247 #endif  // GOOGLE_PROTOBUF_COMPILER_CPP_FIELD_H__
248