1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc.  All rights reserved.
3 // https://developers.google.com/protocol-buffers/
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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 #include <google/protobuf/port_def.inc>
48 
49 namespace google {
50 namespace protobuf {
51 
52 class Message;
53 
54 namespace compiler {
55 
56 // Utility class for launching sub-processes.
57 class PROTOC_EXPORT Subprocess {
58  public:
59   Subprocess();
60   ~Subprocess();
61 
62   enum SearchMode {
63     SEARCH_PATH,  // Use PATH environment variable.
64     EXACT_NAME    // Program is an exact file name; don't use the PATH.
65   };
66 
67   // Start the subprocess.  Currently we don't provide a way to specify
68   // arguments as protoc plugins don't have any.
69   void Start(const std::string& program, SearchMode search_mode);
70 
71   // Serialize the input message and pipe it to the subprocess's stdin, then
72   // close the pipe.  Meanwhile, read from the subprocess's stdout and parse
73   // the data into *output.  All this is done carefully to avoid deadlocks.
74   // Returns true if successful.  On any sort of error, returns false and sets
75   // *error to a description of the problem.
76   bool Communicate(const Message& input, Message* output, std::string* error);
77 
78 #ifdef _WIN32
79   // Given an error code, returns a human-readable error message.  This is
80   // defined here so that CommandLineInterface can share it.
81   static std::string Win32ErrorMessage(DWORD error_code);
82 #endif
83 
84  private:
85 #ifdef _WIN32
86   DWORD process_start_error_;
87   HANDLE child_handle_;
88 
89   // The file handles for our end of the child's pipes.  We close each and
90   // set it to NULL when no longer needed.
91   HANDLE child_stdin_;
92   HANDLE child_stdout_;
93 
94 #else  // _WIN32
95   pid_t child_pid_;
96 
97   // The file descriptors for our end of the child's pipes.  We close each and
98   // set it to -1 when no longer needed.
99   int child_stdin_;
100   int child_stdout_;
101 
102 #endif  // !_WIN32
103 };
104 
105 }  // namespace compiler
106 }  // namespace protobuf
107 }  // namespace google
108 
109 #include <google/protobuf/port_undef.inc>
110 
111 #endif  // GOOGLE_PROTOBUF_COMPILER_SUBPROCESS_H__
112