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// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// Author: kenton@google.com (Kenton Varda)
// Based on original Protocol Buffers design by
// Sanjay Ghemawat, Jeff Dean, and others.
//
// Defines the abstract interface implemented by each of the language-specific
// code generators.
#ifndef GOOGLE_PROTOBUF_COMPILER_CODE_GENERATOR_H__
#define GOOGLE_PROTOBUF_COMPILER_CODE_GENERATOR_H__
#include <google/protobuf/stubs/common.h>
#include <string>
#include <vector>
#include <utility>
namespace google {
namespace protobuf {
namespace io { class ZeroCopyOutputStream; }
class FileDescriptor;
namespace compiler {
// Defined in this file.
class CodeGenerator;
class GeneratorContext;
// The abstract interface to a class which generates code implementing a
// particular proto file in a particular language. A number of these may
// be registered with CommandLineInterface to support various languages.
class LIBPROTOC_EXPORT CodeGenerator {
public:
inline CodeGenerator() {}
virtual ~CodeGenerator();
// Generates code for the given proto file, generating one or more files in
// the given output directory.
//
// A parameter to be passed to the generator can be specified on the
// command line. This is intended to be used by Java and similar languages
// to specify which specific class from the proto file is to be generated,
// though it could have other uses as well. It is empty if no parameter was
// given.
//
// Returns true if successful. Otherwise, sets *error to a description of
// the problem (e.g. "invalid parameter") and returns false.
virtual bool Generate(const FileDescriptor* file,
const string& parameter,
GeneratorContext* generator_context,
string* error) const = 0;
// Generates code for all given proto files, generating one or more files in
// the given output directory.
//
// This method should be called instead of |Generate()| when
// |HasGenerateAll()| returns |true|. It is used to emulate legacy semantics
// when more than one `.proto` file is specified on one compiler invocation.
//
// WARNING: Please do not use unless legacy semantics force the code generator
// to produce a single output file for all input files, or otherwise require
// an examination of all input files first. The canonical code generator
// design produces one output file per input .proto file, and we do not wish
// to encourage alternate designs.
//
// A parameter is given as passed on the command line, as in |Generate()|
// above.
//
// Returns true if successful. Otherwise, sets *error to a description of
// the problem (e.g. "invalid parameter") and returns false.
virtual bool GenerateAll(const vector<const FileDescriptor*>& files,
const string& parameter,
GeneratorContext* generator_context,
string* error) const {
*error = "Unimplemented GenerateAll() method.";
return false;
}
// Returns true if the code generator expects to receive all FileDescriptors
// at once (via |GenerateAll()|), rather than one at a time (via
// |Generate()|). This is required to implement legacy semantics.
virtual bool HasGenerateAll() const { return false; }
private:
GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(CodeGenerator);
};
// CodeGenerators generate one or more files in a given directory. This
// abstract interface represents the directory to which the CodeGenerator is
// to write and other information about the context in which the Generator
// runs.
class LIBPROTOC_EXPORT GeneratorContext {
public:
inline GeneratorContext() {}
virtual ~GeneratorContext();
// Opens the given file, truncating it if it exists, and returns a
// ZeroCopyOutputStream that writes to the file. The caller takes ownership
// of the returned object. This method never fails (a dummy stream will be
// returned instead).
//
// The filename given should be relative to the root of the source tree.
// E.g. the C++ generator, when generating code for "foo/bar.proto", will
// generate the files "foo/bar.pb.h" and "foo/bar.pb.cc"; note that
// "foo/" is included in these filenames. The filename is not allowed to
// contain "." or ".." components.
virtual io::ZeroCopyOutputStream* Open(const string& filename) = 0;
// Similar to Open() but the output will be appended to the file if exists
virtual io::ZeroCopyOutputStream* OpenForAppend(const string& filename);
// Creates a ZeroCopyOutputStream which will insert code into the given file
// at the given insertion point. See plugin.proto (plugin.pb.h) for more
// information on insertion points. The default implementation
// assert-fails -- it exists only for backwards-compatibility.
//
// WARNING: This feature is currently EXPERIMENTAL and is subject to change.
virtual io::ZeroCopyOutputStream* OpenForInsert(
const string& filename, const string& insertion_point);
// Returns a vector of FileDescriptors for all the files being compiled
// in this run. Useful for languages, such as Go, that treat files
// differently when compiled as a set rather than individually.
virtual void ListParsedFiles(vector<const FileDescriptor*>* output);
private:
GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(GeneratorContext);
};
// The type GeneratorContext was once called OutputDirectory. This typedef
// provides backward compatibility.
typedef GeneratorContext OutputDirectory;
// Several code generators treat the parameter argument as holding a
// list of options separated by commas. This helper function parses
// a set of comma-delimited name/value pairs: e.g.,
// "foo=bar,baz,qux=corge"
// parses to the pairs:
// ("foo", "bar"), ("baz", ""), ("qux", "corge")
extern void ParseGeneratorParameter(const string&,
vector<pair<string, string> >*);
} // namespace compiler
} // namespace protobuf
} // namespace google
#endif // GOOGLE_PROTOBUF_COMPILER_CODE_GENERATOR_H__