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 //
33 // Front-end for protoc code generator plugins written in C++.
34 //
35 // To implement a protoc plugin in C++, simply write an implementation of
36 // CodeGenerator, then create a main() function like:
37 //   int main(int argc, char* argv[]) {
38 //     MyCodeGenerator generator;
39 //     return google::protobuf::compiler::PluginMain(argc, argv, &generator);
40 //   }
41 // You must link your plugin against libprotobuf and libprotoc.
42 //
43 // The core part of PluginMain is to invoke the given CodeGenerator on a
44 // CodeGeneratorRequest to generate a CodeGeneratorResponse. This part is
45 // abstracted out and made into function GenerateCode so that it can be reused,
46 // for example, to implement a variant of PluginMain that does some
47 // preprocessing on the input CodeGeneratorRequest before feeding the request
48 // to the given code generator.
49 //
50 // To get protoc to use the plugin, do one of the following:
51 // * Place the plugin binary somewhere in the PATH and give it the name
52 //   "protoc-gen-NAME" (replacing "NAME" with the name of your plugin).  If you
53 //   then invoke protoc with the parameter --NAME_out=OUT_DIR (again, replace
54 //   "NAME" with your plugin's name), protoc will invoke your plugin to generate
55 //   the output, which will be placed in OUT_DIR.
56 // * Place the plugin binary anywhere, with any name, and pass the --plugin
57 //   parameter to protoc to direct it to your plugin like so:
58 //     protoc --plugin=protoc-gen-NAME=path/to/mybinary --NAME_out=OUT_DIR
59 //   On Windows, make sure to include the .exe suffix:
60 //     protoc --plugin=protoc-gen-NAME=path/to/mybinary.exe --NAME_out=OUT_DIR
61 
62 #ifndef GOOGLE_PROTOBUF_COMPILER_PLUGIN_H__
63 #define GOOGLE_PROTOBUF_COMPILER_PLUGIN_H__
64 
65 #include <string>
66 
67 #include <google/protobuf/port_def.inc>
68 
69 namespace google {
70 namespace protobuf {
71 namespace compiler {
72 
73 class CodeGenerator;  // code_generator.h
74 class CodeGeneratorRequest;
75 class CodeGeneratorResponse;
76 
77 // Implements main() for a protoc plugin exposing the given code generator.
78 PROTOC_EXPORT int PluginMain(int argc, char* argv[],
79                              const CodeGenerator* generator);
80 
81 // Generates code using the given code generator. Returns true if the code
82 // generation is successful. If the code geneartion fails, error_msg may be
83 // populated to describe the failure cause.
84 bool GenerateCode(const CodeGeneratorRequest& request,
85                   const CodeGenerator& generator,
86                   CodeGeneratorResponse* response, std::string* error_msg);
87 
88 }  // namespace compiler
89 }  // namespace protobuf
90 }  // namespace google
91 
92 #include <google/protobuf/port_undef.inc>
93 
94 #endif  // GOOGLE_PROTOBUF_COMPILER_PLUGIN_H__
95