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,
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29// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30
31// Author: kenton@google.com (Kenton Varda)
32
33#ifndef GOOGLE_PROTOBUF_COMPILER_SUBPROCESS_H__
34#define GOOGLE_PROTOBUF_COMPILER_SUBPROCESS_H__
35
36#ifdef _WIN32
37#define WIN32_LEAN_AND_MEAN   // right...
38#include <windows.h>
39#else  // _WIN32
40#include <sys/types.h>
41#include <unistd.h>
42#endif  // !_WIN32
43#include <google/protobuf/stubs/common.h>
44
45#include <string>
46
47
48namespace google {
49namespace protobuf {
50
51class Message;
52
53namespace compiler {
54
55// Utility class for launching sub-processes.
56class Subprocess {
57 public:
58  Subprocess();
59  ~Subprocess();
60
61  enum SearchMode {
62    SEARCH_PATH,   // Use PATH environment variable.
63    EXACT_NAME     // Program is an exact file name; don't use the PATH.
64  };
65
66  // Start the subprocess.  Currently we don't provide a way to specify
67  // arguments as protoc plugins don't have any.
68  void Start(const string& program, SearchMode search_mode);
69
70  // Serialize the input message and pipe it to the subprocess's stdin, then
71  // close the pipe.  Meanwhile, read from the subprocess's stdout and parse
72  // the data into *output.  All this is done carefully to avoid deadlocks.
73  // Returns true if successful.  On any sort of error, returns false and sets
74  // *error to a description of the problem.
75  bool Communicate(const Message& input, Message* output, string* error);
76
77#ifdef _WIN32
78  // Given an error code, returns a human-readable error message.  This is
79  // defined here so that CommandLineInterface can share it.
80  static string Win32ErrorMessage(DWORD error_code);
81#endif
82
83 private:
84#ifdef _WIN32
85  DWORD process_start_error_;
86  HANDLE child_handle_;
87
88  // The file handles for our end of the child's pipes.  We close each and
89  // set it to NULL when no longer needed.
90  HANDLE child_stdin_;
91  HANDLE child_stdout_;
92
93#else  // _WIN32
94  pid_t child_pid_;
95
96  // The file descriptors for our end of the child's pipes.  We close each and
97  // set it to -1 when no longer needed.
98  int child_stdin_;
99  int child_stdout_;
100
101#endif  // !_WIN32
102};
103
104}  // namespace compiler
105}  // namespace protobuf
106
107}  // namespace google
108#endif  // GOOGLE_PROTOBUF_COMPILER_SUBPROCESS_H__
109