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 #include <Python.h>
32
33 namespace google {
34 namespace protobuf {
35 namespace python {
36
37 // Version constant.
38 // This is either 0 for python, 1 for CPP V1, 2 for CPP V2.
39 //
40 // 0 is default and is equivalent to
41 // PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=python
42 //
43 // 1 is set with -DPYTHON_PROTO2_CPP_IMPL_V1 and is equivalent to
44 // PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=cpp
45 // and
46 // PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION_VERSION=1
47 //
48 // 2 is set with -DPYTHON_PROTO2_CPP_IMPL_V2 and is equivalent to
49 // PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=cpp
50 // and
51 // PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION_VERSION=2
52 #ifdef PYTHON_PROTO2_CPP_IMPL_V1
53 #error "PYTHON_PROTO2_CPP_IMPL_V1 is no longer supported."
54 #else
55 #ifdef PYTHON_PROTO2_CPP_IMPL_V2
56 static int kImplVersion = 2;
57 #else
58 #ifdef PYTHON_PROTO2_PYTHON_IMPL
59 static int kImplVersion = 0;
60 #else
61
62 static int kImplVersion = -1; // -1 means "Unspecified by compiler flags".
63
64 #endif // PYTHON_PROTO2_PYTHON_IMPL
65 #endif // PYTHON_PROTO2_CPP_IMPL_V2
66 #endif // PYTHON_PROTO2_CPP_IMPL_V1
67
68 static const char* kImplVersionName = "api_version";
69
70 static const char* kModuleName = "_api_implementation";
71 static const char kModuleDocstring[] =
72 "_api_implementation is a module that exposes compile-time constants that\n"
73 "determine the default API implementation to use for Python proto2.\n"
74 "\n"
75 "It complements api_implementation.py by setting defaults using "
76 "compile-time\n"
77 "constants defined in C, such that one can set defaults at compilation\n"
78 "(e.g. with blaze flag --copt=-DPYTHON_PROTO2_CPP_IMPL_V2).";
79
80 #if PY_MAJOR_VERSION >= 3
81 static struct PyModuleDef _module = {PyModuleDef_HEAD_INIT,
82 kModuleName,
83 kModuleDocstring,
84 -1,
85 NULL,
86 NULL,
87 NULL,
88 NULL,
89 NULL};
90 #define INITFUNC PyInit__api_implementation
91 #define INITFUNC_ERRORVAL NULL
92 #else
93 #define INITFUNC init_api_implementation
94 #define INITFUNC_ERRORVAL
95 #endif
96
97 extern "C" {
INITFUNC()98 PyMODINIT_FUNC INITFUNC() {
99 #if PY_MAJOR_VERSION >= 3
100 PyObject* module = PyModule_Create(&_module);
101 #else
102 PyObject* module = Py_InitModule3(const_cast<char*>(kModuleName), NULL,
103 const_cast<char*>(kModuleDocstring));
104 #endif
105 if (module == NULL) {
106 return INITFUNC_ERRORVAL;
107 }
108
109 // Adds the module variable "api_version".
110 if (PyModule_AddIntConstant(module, const_cast<char*>(kImplVersionName),
111 kImplVersion))
112 #if PY_MAJOR_VERSION < 3
113 return;
114 #else
115 {
116 Py_DECREF(module);
117 return NULL;
118 }
119
120 return module;
121 #endif
122 }
123 }
124
125 } // namespace python
126 } // namespace protobuf
127 } // namespace google
128