1 2 /* Support for dynamic loading of extension modules */ 3 4 #include "Python.h" 5 6 /* ./configure sets HAVE_DYNAMIC_LOADING if dynamic loading of modules is 7 supported on this platform. configure will then compile and link in one 8 of the dynload_*.c files, as appropriate. We will call a function in 9 those modules to get a function pointer to the module's init function. 10 */ 11 #ifdef HAVE_DYNAMIC_LOADING 12 13 #include "importdl.h" 14 15 #ifdef MS_WINDOWS 16 extern dl_funcptr _PyImport_FindSharedFuncptrWindows(const char *prefix, 17 const char *shortname, 18 PyObject *pathname, 19 FILE *fp); 20 #else 21 extern dl_funcptr _PyImport_FindSharedFuncptr(const char *prefix, 22 const char *shortname, 23 const char *pathname, FILE *fp); 24 #endif 25 26 static const char * const ascii_only_prefix = "PyInit"; 27 static const char * const nonascii_prefix = "PyInitU"; 28 29 /* Get the variable part of a module's export symbol name. 30 * Returns a bytes instance. For non-ASCII-named modules, the name is 31 * encoded as per PEP 489. 32 * The hook_prefix pointer is set to either ascii_only_prefix or 33 * nonascii_prefix, as appropriate. 34 */ 35 static PyObject * 36 get_encoded_name(PyObject *name, const char **hook_prefix) { 37 PyObject *tmp; 38 PyObject *encoded = NULL; 39 PyObject *modname = NULL; 40 Py_ssize_t name_len, lastdot; 41 _Py_IDENTIFIER(replace); 42 43 /* Get the short name (substring after last dot) */ 44 name_len = PyUnicode_GetLength(name); 45 lastdot = PyUnicode_FindChar(name, '.', 0, name_len, -1); 46 if (lastdot < -1) { 47 return NULL; 48 } else if (lastdot >= 0) { 49 tmp = PyUnicode_Substring(name, lastdot + 1, name_len); 50 if (tmp == NULL) 51 return NULL; 52 name = tmp; 53 /* "name" now holds a new reference to the substring */ 54 } else { 55 Py_INCREF(name); 56 } 57 58 /* Encode to ASCII or Punycode, as needed */ 59 encoded = PyUnicode_AsEncodedString(name, "ascii", NULL); 60 if (encoded != NULL) { 61 *hook_prefix = ascii_only_prefix; 62 } else { 63 if (PyErr_ExceptionMatches(PyExc_UnicodeEncodeError)) { 64 PyErr_Clear(); 65 encoded = PyUnicode_AsEncodedString(name, "punycode", NULL); 66 if (encoded == NULL) { 67 goto error; 68 } 69 *hook_prefix = nonascii_prefix; 70 } else { 71 goto error; 72 } 73 } 74 75 /* Replace '-' by '_' */ 76 modname = _PyObject_CallMethodId(encoded, &PyId_replace, "cc", '-', '_'); 77 if (modname == NULL) 78 goto error; 79 80 Py_DECREF(name); 81 Py_DECREF(encoded); 82 return modname; 83 error: 84 Py_DECREF(name); 85 Py_XDECREF(encoded); 86 return NULL; 87 } 88 89 PyObject * 90 _PyImport_LoadDynamicModuleWithSpec(PyObject *spec, FILE *fp) 91 { 92 #ifndef MS_WINDOWS 93 PyObject *pathbytes = NULL; 94 #endif 95 PyObject *name_unicode = NULL, *name = NULL, *path = NULL, *m = NULL; 96 const char *name_buf, *hook_prefix; 97 const char *oldcontext; 98 dl_funcptr exportfunc; 99 PyModuleDef *def; 100 PyObject *(*p0)(void); 101 102 name_unicode = PyObject_GetAttrString(spec, "name"); 103 if (name_unicode == NULL) { 104 return NULL; 105 } 106 if (!PyUnicode_Check(name_unicode)) { 107 PyErr_SetString(PyExc_TypeError, 108 "spec.name must be a string"); 109 goto error; 110 } 111 112 name = get_encoded_name(name_unicode, &hook_prefix); 113 if (name == NULL) { 114 goto error; 115 } 116 name_buf = PyBytes_AS_STRING(name); 117 118 path = PyObject_GetAttrString(spec, "origin"); 119 if (path == NULL) 120 goto error; 121 122 #ifdef MS_WINDOWS 123 exportfunc = _PyImport_FindSharedFuncptrWindows(hook_prefix, name_buf, 124 path, fp); 125 #else 126 pathbytes = PyUnicode_EncodeFSDefault(path); 127 if (pathbytes == NULL) 128 goto error; 129 exportfunc = _PyImport_FindSharedFuncptr(hook_prefix, name_buf, 130 PyBytes_AS_STRING(pathbytes), 131 fp); 132 Py_DECREF(pathbytes); 133 #endif 134 135 if (exportfunc == NULL) { 136 if (!PyErr_Occurred()) { 137 PyObject *msg; 138 msg = PyUnicode_FromFormat( 139 "dynamic module does not define " 140 "module export function (%s_%s)", 141 hook_prefix, name_buf); 142 if (msg == NULL) 143 goto error; 144 PyErr_SetImportError(msg, name_unicode, path); 145 Py_DECREF(msg); 146 } 147 goto error; 148 } 149 150 p0 = (PyObject *(*)(void))exportfunc; 151 152 /* Package context is needed for single-phase init */ 153 oldcontext = _Py_PackageContext; 154 _Py_PackageContext = PyUnicode_AsUTF8(name_unicode); 155 if (_Py_PackageContext == NULL) { 156 _Py_PackageContext = oldcontext; 157 goto error; 158 } 159 m = p0(); 160 _Py_PackageContext = oldcontext; 161 162 if (m == NULL) { 163 if (!PyErr_Occurred()) { 164 PyErr_Format( 165 PyExc_SystemError, 166 "initialization of %s failed without raising an exception", 167 name_buf); 168 } 169 goto error; 170 } else if (PyErr_Occurred()) { 171 PyErr_Clear(); 172 PyErr_Format( 173 PyExc_SystemError, 174 "initialization of %s raised unreported exception", 175 name_buf); 176 m = NULL; 177 goto error; 178 } 179 if (Py_TYPE(m) == NULL) { 180 /* This can happen when a PyModuleDef is returned without calling 181 * PyModuleDef_Init on it 182 */ 183 PyErr_Format(PyExc_SystemError, 184 "init function of %s returned uninitialized object", 185 name_buf); 186 m = NULL; /* prevent segfault in DECREF */ 187 goto error; 188 } 189 if (PyObject_TypeCheck(m, &PyModuleDef_Type)) { 190 Py_DECREF(name_unicode); 191 Py_DECREF(name); 192 Py_DECREF(path); 193 return PyModule_FromDefAndSpec((PyModuleDef*)m, spec); 194 } 195 196 /* Fall back to single-phase init mechanism */ 197 198 if (hook_prefix == nonascii_prefix) { 199 /* don't allow legacy init for non-ASCII module names */ 200 PyErr_Format( 201 PyExc_SystemError, 202 "initialization of * did not return PyModuleDef", 203 name_buf); 204 goto error; 205 } 206 207 /* Remember pointer to module init function. */ 208 def = PyModule_GetDef(m); 209 if (def == NULL) { 210 PyErr_Format(PyExc_SystemError, 211 "initialization of %s did not return an extension " 212 "module", name_buf); 213 goto error; 214 } 215 def->m_base.m_init = p0; 216 217 /* Remember the filename as the __file__ attribute */ 218 if (PyModule_AddObject(m, "__file__", path) < 0) 219 PyErr_Clear(); /* Not important enough to report */ 220 else 221 Py_INCREF(path); 222 223 PyObject *modules = PyImport_GetModuleDict(); 224 if (_PyImport_FixupExtensionObject(m, name_unicode, path, modules) < 0) 225 goto error; 226 227 Py_DECREF(name_unicode); 228 Py_DECREF(name); 229 Py_DECREF(path); 230 231 return m; 232 233 error: 234 Py_DECREF(name_unicode); 235 Py_XDECREF(name); 236 Py_XDECREF(path); 237 Py_XDECREF(m); 238 return NULL; 239 } 240 241 #endif /* HAVE_DYNAMIC_LOADING */ 242
