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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,
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     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 (at) google.com (Kenton Varda)
     32 //  Based on original Protocol Buffers design by
     33 //  Sanjay Ghemawat, Jeff Dean, and others.
     34 //
     35 // Defines the abstract interface implemented by each of the language-specific
     36 // code generators.
     37 
     38 #ifndef GOOGLE_PROTOBUF_COMPILER_CODE_GENERATOR_H__
     39 #define GOOGLE_PROTOBUF_COMPILER_CODE_GENERATOR_H__
     40 
     41 #include <google/protobuf/stubs/common.h>
     42 #include <string>
     43 #include <vector>
     44 #include <utility>
     45 
     46 namespace google {
     47 namespace protobuf {
     48 
     49 namespace io { class ZeroCopyOutputStream; }
     50 class FileDescriptor;
     51 
     52 namespace compiler {
     53 
     54 // Defined in this file.
     55 class CodeGenerator;
     56 class OutputDirectory;
     57 
     58 // The abstract interface to a class which generates code implementing a
     59 // particular proto file in a particular language.  A number of these may
     60 // be registered with CommandLineInterface to support various languages.
     61 class LIBPROTOC_EXPORT CodeGenerator {
     62  public:
     63   inline CodeGenerator() {}
     64   virtual ~CodeGenerator();
     65 
     66   // Generates code for the given proto file, generating one or more files in
     67   // the given output directory.
     68   //
     69   // A parameter to be passed to the generator can be specified on the
     70   // command line.  This is intended to be used by Java and similar languages
     71   // to specify which specific class from the proto file is to be generated,
     72   // though it could have other uses as well.  It is empty if no parameter was
     73   // given.
     74   //
     75   // Returns true if successful.  Otherwise, sets *error to a description of
     76   // the problem (e.g. "invalid parameter") and returns false.
     77   virtual bool Generate(const FileDescriptor* file,
     78                         const string& parameter,
     79                         OutputDirectory* output_directory,
     80                         string* error) const = 0;
     81 
     82  private:
     83   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(CodeGenerator);
     84 };
     85 
     86 // CodeGenerators generate one or more files in a given directory.  This
     87 // abstract interface represents the directory to which the CodeGenerator is
     88 // to write.
     89 class LIBPROTOC_EXPORT OutputDirectory {
     90  public:
     91   inline OutputDirectory() {}
     92   virtual ~OutputDirectory();
     93 
     94   // Opens the given file, truncating it if it exists, and returns a
     95   // ZeroCopyOutputStream that writes to the file.  The caller takes ownership
     96   // of the returned object.  This method never fails (a dummy stream will be
     97   // returned instead).
     98   //
     99   // The filename given should be relative to the root of the source tree.
    100   // E.g. the C++ generator, when generating code for "foo/bar.proto", will
    101   // generate the files "foo/bar.pb.h" and "foo/bar.pb.cc"; note that
    102   // "foo/" is included in these filenames.  The filename is not allowed to
    103   // contain "." or ".." components.
    104   virtual io::ZeroCopyOutputStream* Open(const string& filename) = 0;
    105 
    106   // Creates a ZeroCopyOutputStream which will insert code into the given file
    107   // at the given insertion point.  See plugin.proto (plugin.pb.h) for more
    108   // information on insertion points.  The default implementation
    109   // assert-fails -- it exists only for backwards-compatibility.
    110   //
    111   // WARNING:  This feature is currently EXPERIMENTAL and is subject to change.
    112   virtual io::ZeroCopyOutputStream* OpenForInsert(
    113       const string& filename, const string& insertion_point);
    114 
    115  private:
    116   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(OutputDirectory);
    117 };
    118 
    119 // Several code generators treat the parameter argument as holding a
    120 // list of options separated by commas.  This helper function parses
    121 // a set of comma-delimited name/value pairs: e.g.,
    122 //   "foo=bar,baz,qux=corge"
    123 // parses to the pairs:
    124 //   ("foo", "bar"), ("baz", ""), ("qux", "corge")
    125 extern void ParseGeneratorParameter(const string&,
    126             vector<pair<string, string> >*);
    127 
    128 }  // namespace compiler
    129 }  // namespace protobuf
    130 
    131 }  // namespace google
    132 #endif  // GOOGLE_PROTOBUF_COMPILER_CODE_GENERATOR_H__
    133