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1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc.  All rights reserved.
3 // http://code.google.com/p/protobuf/
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 // Implements the Protocol Compiler front-end such that it may be reused by
36 // custom compilers written to support other languages.
37 
38 #ifndef GOOGLE_PROTOBUF_COMPILER_COMMAND_LINE_INTERFACE_H__
39 #define GOOGLE_PROTOBUF_COMPILER_COMMAND_LINE_INTERFACE_H__
40 
41 #include <google/protobuf/stubs/common.h>
42 #include <string>
43 #include <vector>
44 #include <map>
45 #include <set>
46 #include <utility>
47 
48 namespace google {
49 namespace protobuf {
50 
51 class FileDescriptor;        // descriptor.h
52 class DescriptorPool;        // descriptor.h
53 class FileDescriptorProto;   // descriptor.pb.h
54 template<typename T> class RepeatedPtrField;  // repeated_field.h
55 
56 namespace compiler {
57 
58 class CodeGenerator;        // code_generator.h
59 class OutputDirectory;      // code_generator.h
60 class DiskSourceTree;       // importer.h
61 
62 // This class implements the command-line interface to the protocol compiler.
63 // It is designed to make it very easy to create a custom protocol compiler
64 // supporting the languages of your choice.  For example, if you wanted to
65 // create a custom protocol compiler binary which includes both the regular
66 // C++ support plus support for your own custom output "Foo", you would
67 // write a class "FooGenerator" which implements the CodeGenerator interface,
68 // then write a main() procedure like this:
69 //
70 //   int main(int argc, char* argv[]) {
71 //     google::protobuf::compiler::CommandLineInterface cli;
72 //
73 //     // Support generation of C++ source and headers.
74 //     google::protobuf::compiler::cpp::CppGenerator cpp_generator;
75 //     cli.RegisterGenerator("--cpp_out", &cpp_generator,
76 //       "Generate C++ source and header.");
77 //
78 //     // Support generation of Foo code.
79 //     FooGenerator foo_generator;
80 //     cli.RegisterGenerator("--foo_out", &foo_generator,
81 //       "Generate Foo file.");
82 //
83 //     return cli.Run(argc, argv);
84 //   }
85 //
86 // The compiler is invoked with syntax like:
87 //   protoc --cpp_out=outdir --foo_out=outdir --proto_path=src src/foo.proto
88 //
89 // For a full description of the command-line syntax, invoke it with --help.
90 class LIBPROTOC_EXPORT CommandLineInterface {
91  public:
92   CommandLineInterface();
93   ~CommandLineInterface();
94 
95   // Register a code generator for a language.
96   //
97   // Parameters:
98   // * flag_name: The command-line flag used to specify an output file of
99   //   this type.  The name must start with a '-'.  If the name is longer
100   //   than one letter, it must start with two '-'s.
101   // * generator: The CodeGenerator which will be called to generate files
102   //   of this type.
103   // * help_text: Text describing this flag in the --help output.
104   //
105   // Some generators accept extra parameters.  You can specify this parameter
106   // on the command-line by placing it before the output directory, separated
107   // by a colon:
108   //   protoc --foo_out=enable_bar:outdir
109   // The text before the colon is passed to CodeGenerator::Generate() as the
110   // "parameter".
111   void RegisterGenerator(const string& flag_name,
112                          CodeGenerator* generator,
113                          const string& help_text);
114 
115   // Enables "plugins".  In this mode, if a command-line flag ends with "_out"
116   // but does not match any registered generator, the compiler will attempt to
117   // find a "plugin" to implement the generator.  Plugins are just executables.
118   // They should live somewhere in the PATH.
119   //
120   // The compiler determines the executable name to search for by concatenating
121   // exe_name_prefix with the unrecognized flag name, removing "_out".  So, for
122   // example, if exe_name_prefix is "protoc-" and you pass the flag --foo_out,
123   // the compiler will try to run the program "protoc-foo".
124   //
125   // The plugin program should implement the following usage:
126   //   plugin [--out=OUTDIR] [--parameter=PARAMETER] PROTO_FILES < DESCRIPTORS
127   // --out indicates the output directory (as passed to the --foo_out
128   // parameter); if omitted, the current directory should be used.  --parameter
129   // gives the generator parameter, if any was provided.  The PROTO_FILES list
130   // the .proto files which were given on the compiler command-line; these are
131   // the files for which the plugin is expected to generate output code.
132   // Finally, DESCRIPTORS is an encoded FileDescriptorSet (as defined in
133   // descriptor.proto).  This is piped to the plugin's stdin.  The set will
134   // include descriptors for all the files listed in PROTO_FILES as well as
135   // all files that they import.  The plugin MUST NOT attempt to read the
136   // PROTO_FILES directly -- it must use the FileDescriptorSet.
137   //
138   // The plugin should generate whatever files are necessary, as code generators
139   // normally do.  It should write the names of all files it generates to
140   // stdout.  The names should be relative to the output directory, NOT absolute
141   // names or relative to the current directory.  If any errors occur, error
142   // messages should be written to stderr.  If an error is fatal, the plugin
143   // should exit with a non-zero exit code.
144   void AllowPlugins(const string& exe_name_prefix);
145 
146   // Run the Protocol Compiler with the given command-line parameters.
147   // Returns the error code which should be returned by main().
148   //
149   // It may not be safe to call Run() in a multi-threaded environment because
150   // it calls strerror().  I'm not sure why you'd want to do this anyway.
151   int Run(int argc, const char* const argv[]);
152 
153   // Call SetInputsAreCwdRelative(true) if the input files given on the command
154   // line should be interpreted relative to the proto import path specified
155   // using --proto_path or -I flags.  Otherwise, input file names will be
156   // interpreted relative to the current working directory (or as absolute
157   // paths if they start with '/'), though they must still reside inside
158   // a directory given by --proto_path or the compiler will fail.  The latter
159   // mode is generally more intuitive and easier to use, especially e.g. when
160   // defining implicit rules in Makefiles.
SetInputsAreProtoPathRelative(bool enable)161   void SetInputsAreProtoPathRelative(bool enable) {
162     inputs_are_proto_path_relative_ = enable;
163   }
164 
165   // Provides some text which will be printed when the --version flag is
166   // used.  The version of libprotoc will also be printed on the next line
167   // after this text.
SetVersionInfo(const string & text)168   void SetVersionInfo(const string& text) {
169     version_info_ = text;
170   }
171 
172 
173  private:
174   // -----------------------------------------------------------------
175 
176   class ErrorPrinter;
177   class MemoryOutputDirectory;
178   class MemoryOutputStream;
179 
180   // Clear state from previous Run().
181   void Clear();
182 
183   // Remaps each file in input_files_ so that it is relative to one of the
184   // directories in proto_path_.  Returns false if an error occurred.  This
185   // is only used if inputs_are_proto_path_relative_ is false.
186   bool MakeInputsBeProtoPathRelative(
187     DiskSourceTree* source_tree);
188 
189   // Parse all command-line arguments.
190   bool ParseArguments(int argc, const char* const argv[]);
191 
192   // Parses a command-line argument into a name/value pair.  Returns
193   // true if the next argument in the argv should be used as the value,
194   // false otherwise.
195   //
196   // Exmaples:
197   //   "-Isrc/protos" ->
198   //     name = "-I", value = "src/protos"
199   //   "--cpp_out=src/foo.pb2.cc" ->
200   //     name = "--cpp_out", value = "src/foo.pb2.cc"
201   //   "foo.proto" ->
202   //     name = "", value = "foo.proto"
203   bool ParseArgument(const char* arg, string* name, string* value);
204 
205   // Interprets arguments parsed with ParseArgument.
206   bool InterpretArgument(const string& name, const string& value);
207 
208   // Print the --help text to stderr.
209   void PrintHelpText();
210 
211   // Generate the given output file from the given input.
212   struct OutputDirective;  // see below
213   bool GenerateOutput(const vector<const FileDescriptor*>& parsed_files,
214                       const OutputDirective& output_directive,
215                       OutputDirectory* output_directory);
216   bool GeneratePluginOutput(const vector<const FileDescriptor*>& parsed_files,
217                             const string& plugin_name,
218                             const string& parameter,
219                             OutputDirectory* output_directory,
220                             string* error);
221 
222   // Implements --encode and --decode.
223   bool EncodeOrDecode(const DescriptorPool* pool);
224 
225   // Implements the --descriptor_set_out option.
226   bool WriteDescriptorSet(const vector<const FileDescriptor*> parsed_files);
227 
228   // Get all transitive dependencies of the given file (including the file
229   // itself), adding them to the given list of FileDescriptorProtos.  The
230   // protos will be ordered such that every file is listed before any file that
231   // depends on it, so that you can call DescriptorPool::BuildFile() on them
232   // in order.  Any files in *already_seen will not be added, and each file
233   // added will be inserted into *already_seen.
234   static void GetTransitiveDependencies(
235       const FileDescriptor* file,
236       set<const FileDescriptor*>* already_seen,
237       RepeatedPtrField<FileDescriptorProto>* output);
238 
239   // -----------------------------------------------------------------
240 
241   // The name of the executable as invoked (i.e. argv[0]).
242   string executable_name_;
243 
244   // Version info set with SetVersionInfo().
245   string version_info_;
246 
247   // Map from flag names to registered generators.
248   struct GeneratorInfo {
249     CodeGenerator* generator;
250     string help_text;
251   };
252   typedef map<string, GeneratorInfo> GeneratorMap;
253   GeneratorMap generators_;
254 
255   // See AllowPlugins().  If this is empty, plugins aren't allowed.
256   string plugin_prefix_;
257 
258   // Maps specific plugin names to files.  When executing a plugin, this map
259   // is searched first to find the plugin executable.  If not found here, the
260   // PATH (or other OS-specific search strategy) is searched.
261   map<string, string> plugins_;
262 
263   // Stuff parsed from command line.
264   enum Mode {
265     MODE_COMPILE,  // Normal mode:  parse .proto files and compile them.
266     MODE_ENCODE,   // --encode:  read text from stdin, write binary to stdout.
267     MODE_DECODE    // --decode:  read binary from stdin, write text to stdout.
268   };
269 
270   Mode mode_;
271 
272   enum ErrorFormat {
273     ERROR_FORMAT_GCC,   // GCC error output format (default).
274     ERROR_FORMAT_MSVS   // Visual Studio output (--error_format=msvs).
275   };
276 
277   ErrorFormat error_format_;
278 
279   vector<pair<string, string> > proto_path_;  // Search path for proto files.
280   vector<string> input_files_;                // Names of the input proto files.
281 
282   // output_directives_ lists all the files we are supposed to output and what
283   // generator to use for each.
284   struct OutputDirective {
285     string name;                // E.g. "--foo_out"
286     CodeGenerator* generator;   // NULL for plugins
287     string parameter;
288     string output_location;
289   };
290   vector<OutputDirective> output_directives_;
291 
292   // When using --encode or --decode, this names the type we are encoding or
293   // decoding.  (Empty string indicates --decode_raw.)
294   string codec_type_;
295 
296   // If --descriptor_set_out was given, this is the filename to which the
297   // FileDescriptorSet should be written.  Otherwise, empty.
298   string descriptor_set_name_;
299 
300   // True if --include_imports was given, meaning that we should
301   // write all transitive dependencies to the DescriptorSet.  Otherwise, only
302   // the .proto files listed on the command-line are added.
303   bool imports_in_descriptor_set_;
304 
305   // Was the --disallow_services flag used?
306   bool disallow_services_;
307 
308   // See SetInputsAreProtoPathRelative().
309   bool inputs_are_proto_path_relative_;
310 
311   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(CommandLineInterface);
312 };
313 
314 }  // namespace compiler
315 }  // namespace protobuf
316 
317 }  // namespace google
318 #endif  // GOOGLE_PROTOBUF_COMPILER_COMMAND_LINE_INTERFACE_H__
319