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 #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 
48 namespace google {
49 namespace protobuf {
50 
51 class Message;
52 
53 namespace compiler {
54 
55 // Utility class for launching sub-processes.
56 class LIBPROTOC_EXPORT 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