Python/importdl.c

   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 extern dl_funcptr _PyImport_GetDynLoadFunc(const char *name,
  16                                            const char *shortname,
  17                                            const char *pathname, FILE *fp);
  18
  19
  20
  21 PyObject *
  22 _PyImport_LoadDynamicModule(char *name, char *pathname, FILE *fp)
  23 {
  24         PyObject *m;
  25         char *lastdot, *shortname, *packagecontext, *oldcontext;
  26         dl_funcptr p;
  27
  28         if ((m = _PyImport_FindExtension(name, pathname)) != NULL) {
  29                 Py_INCREF(m);
  30                 return m;
  31         }
  32         lastdot = strrchr(name, '.');
  33         if (lastdot == NULL) {
  34                 packagecontext = NULL;
  35                 shortname = name;
  36         }
  37         else {
  38                 packagecontext = name;
  39                 shortname = lastdot+1;
  40         }
  41
  42         p = _PyImport_GetDynLoadFunc(name, shortname, pathname, fp);
  43         if (PyErr_Occurred())
  44                 return NULL;
  45         if (p == NULL) {
  46                 PyErr_Format(PyExc_ImportError,
  47                    "dynamic module does not define init function (init%.200s)",
  48                              shortname);
  49                 return NULL;
  50         }
  51         oldcontext = _Py_PackageContext;
  52         _Py_PackageContext = packagecontext;
  53         (*p)();
  54         _Py_PackageContext = oldcontext;
  55         if (PyErr_Occurred())
  56                 return NULL;
  57
  58         m = PyDict_GetItemString(PyImport_GetModuleDict(), name);
  59         if (m == NULL) {
  60                 PyErr_SetString(PyExc_SystemError,
  61                                 "dynamic module not initialized properly");
  62                 return NULL;
  63         }
  64         /* Remember the filename as the __file__ attribute */
  65         if (PyModule_AddStringConstant(m, "__file__", pathname) < 0)
  66                 PyErr_Clear(); /* Not important enough to report */
  67
  68         if (_PyImport_FixupExtension(name, pathname) == NULL)
  69                 return NULL;
  70         if (Py_VerboseFlag)
  71                 PySys_WriteStderr(
  72                         "import %s # dynamically loaded from %s\n",
  73                         name, pathname);
  74         Py_INCREF(m);
  75         return m;
  76 }
  77
  78 #endif /* HAVE_DYNAMIC_LOADING */