Objects/moduleobject.c

   1 /***********************************************************
   2 Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
   3 The Netherlands.
   4
   5                         All Rights Reserved
   6
   7 Permission to use, copy, modify, and distribute this software and its
   8 documentation for any purpose and without fee is hereby granted,
   9 provided that the above copyright notice appear in all copies and that
  10 both that copyright notice and this permission notice appear in
  11 supporting documentation, and that the names of Stichting Mathematisch
  12 Centrum or CWI or Corporation for National Research Initiatives or
  13 CNRI not be used in advertising or publicity pertaining to
  14 distribution of the software without specific, written prior
  15 permission.
  16
  17 While CWI is the initial source for this software, a modified version
  18 is made available by the Corporation for National Research Initiatives
  19 (CNRI) at the Internet address ftp://ftp.python.org.
  20
  21 STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH
  22 REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
  23 MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH
  24 CENTRUM OR CNRI BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
  25 DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  26 PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  27 TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  28 PERFORMANCE OF THIS SOFTWARE.
  29
  30 ******************************************************************/
  31
  32 /* Module object implementation */
  33
  34 #include "Python.h"
  35
  36 typedef struct {
  37         PyObject_HEAD
  38         PyObject *md_dict;
  39 } PyModuleObject;
  40
  41 PyObject *
  42 PyModule_New(name)
  43         char *name;
  44 {
  45         PyModuleObject *m;
  46         PyObject *nameobj;
  47         m = PyObject_NEW(PyModuleObject, &PyModule_Type);
  48         if (m == NULL)
  49                 return NULL;
  50         nameobj = PyString_FromString(name);
  51         m->md_dict = PyDict_New();
  52         if (m->md_dict == NULL || nameobj == NULL)
  53                 goto fail;
  54         if (PyDict_SetItemString(m->md_dict, "__name__", nameobj) != 0)
  55                 goto fail;
  56         if (PyDict_SetItemString(m->md_dict, "__doc__", Py_None) != 0)
  57                 goto fail;
  58         Py_DECREF(nameobj);
  59         return (PyObject *)m;
  60
  61  fail:
  62         Py_XDECREF(nameobj);
  63         Py_DECREF(m);
  64         return NULL;
  65 }
  66
  67 PyObject *
  68 PyModule_GetDict(m)
  69         PyObject *m;
  70 {
  71         if (!PyModule_Check(m)) {
  72                 PyErr_BadInternalCall();
  73                 return NULL;
  74         }
  75         return ((PyModuleObject *)m) -> md_dict;
  76 }
  77
  78 char *
  79 PyModule_GetName(m)
  80         PyObject *m;
  81 {
  82         PyObject *nameobj;
  83         if (!PyModule_Check(m)) {
  84                 PyErr_BadArgument();
  85                 return NULL;
  86         }
  87         nameobj = PyDict_GetItemString(((PyModuleObject *)m)->md_dict,
  88                                        "__name__");
  89         if (nameobj == NULL || !PyString_Check(nameobj)) {
  90                 PyErr_SetString(PyExc_SystemError, "nameless module");
  91                 return NULL;
  92         }
  93         return PyString_AsString(nameobj);
  94 }
  95
  96 char *
  97 PyModule_GetFilename(m)
  98         PyObject *m;
  99 {
 100         PyObject *fileobj;
 101         if (!PyModule_Check(m)) {
 102                 PyErr_BadArgument();
 103                 return NULL;
 104         }
 105         fileobj = PyDict_GetItemString(((PyModuleObject *)m)->md_dict,
 106                                        "__file__");
 107         if (fileobj == NULL || !PyString_Check(fileobj)) {
 108                 PyErr_SetString(PyExc_SystemError, "module filename missing");
 109                 return NULL;
 110         }
 111         return PyString_AsString(fileobj);
 112 }
 113
 114 void
 115 _PyModule_Clear(m)
 116         PyObject *m;
 117 {
 118         /* To make the execution order of destructors for global
 119            objects a bit more predictable, we first zap all objects
 120            whose name starts with a single underscore, before we clear
 121            the entire dictionary.  We zap them by replacing them with
 122            None, rather than deleting them from the dictionary, to
 123            avoid rehashing the dictionary (to some extent). */
 124
 125         int pos;
 126         PyObject *key, *value;
 127         PyObject *d;
 128
 129         d = ((PyModuleObject *)m)->md_dict;
 130
 131         /* First, clear only names starting with a single underscore */
 132         pos = 0;
 133         while (PyDict_Next(d, &pos, &key, &value)) {
 134                 if (value != Py_None && PyString_Check(key)) {
 135                         char *s = PyString_AsString(key);
 136                         if (s[0] == '_' && s[1] != '_') {
 137                                 if (Py_VerboseFlag > 1)
 138                                     PySys_WriteStderr("#   clear[1] %s\n", s);
 139                                 PyDict_SetItem(d, key, Py_None);
 140                         }
 141                 }
 142         }
 143
 144         /* Next, clear all names except for __builtins__ */
 145         pos = 0;
 146         while (PyDict_Next(d, &pos, &key, &value)) {
 147                 if (value != Py_None && PyString_Check(key)) {
 148                         char *s = PyString_AsString(key);
 149                         if (s[0] != '_' || strcmp(s, "__builtins__") != 0) {
 150                                 if (Py_VerboseFlag > 1)
 151                                     PySys_WriteStderr("#   clear[2] %s\n", s);
 152                                 PyDict_SetItem(d, key, Py_None);
 153                         }
 154                 }
 155         }
 156
 157         /* Note: we leave __builtins__ in place, so that destructors
 158            of non-global objects defined in this module can still use
 159            builtins, in particularly 'None'. */
 160
 161 }
 162
 163 /* Methods */
 164
 165 static void
 166 module_dealloc(m)
 167         PyModuleObject *m;
 168 {
 169         if (m->md_dict != NULL) {
 170                 _PyModule_Clear((PyObject *)m);
 171                 Py_DECREF(m->md_dict);
 172         }
 173         free((char *)m);
 174 }
 175
 176 static PyObject *
 177 module_repr(m)
 178         PyModuleObject *m;
 179 {
 180         char buf[400];
 181         char *name;
 182         char *filename;
 183         name = PyModule_GetName((PyObject *)m);
 184         if (name == NULL) {
 185                 PyErr_Clear();
 186                 name = "?";
 187         }
 188         filename = PyModule_GetFilename((PyObject *)m);
 189         if (filename == NULL) {
 190                 PyErr_Clear();
 191                 sprintf(buf, "<module '%.80s' (built-in)>", name);
 192         } else {
 193                 sprintf(buf, "<module '%.80s' from '%.255s'>", name, filename);
 194         }
 195
 196         return PyString_FromString(buf);
 197 }
 198
 199 static PyObject *
 200 module_getattr(m, name)
 201         PyModuleObject *m;
 202         char *name;
 203 {
 204         PyObject *res;
 205         if (strcmp(name, "__dict__") == 0) {
 206                 Py_INCREF(m->md_dict);
 207                 return m->md_dict;
 208         }
 209         res = PyDict_GetItemString(m->md_dict, name);
 210         if (res == NULL)
 211                 PyErr_SetString(PyExc_AttributeError, name);
 212         else
 213                 Py_INCREF(res);
 214         return res;
 215 }
 216
 217 static int
 218 module_setattr(m, name, v)
 219         PyModuleObject *m;
 220         char *name;
 221         PyObject *v;
 222 {
 223         if (name[0] == '_' && strcmp(name, "__dict__") == 0) {
 224                 PyErr_SetString(PyExc_TypeError,
 225                                 "read-only special attribute");
 226                 return -1;
 227         }
 228         if (v == NULL) {
 229                 int rv = PyDict_DelItemString(m->md_dict, name);
 230                 if (rv < 0)
 231                         PyErr_SetString(PyExc_AttributeError,
 232                                    "delete non-existing module attribute");
 233                 return rv;
 234         }
 235         else
 236                 return PyDict_SetItemString(m->md_dict, name, v);
 237 }
 238
 239 PyTypeObject PyModule_Type = {
 240         PyObject_HEAD_INIT(&PyType_Type)
 241         0,                      /*ob_size*/
 242         "module",               /*tp_name*/
 243         sizeof(PyModuleObject), /*tp_size*/
 244         0,                      /*tp_itemsize*/
 245         (destructor)module_dealloc, /*tp_dealloc*/
 246         0,                      /*tp_print*/
 247         (getattrfunc)module_getattr, /*tp_getattr*/
 248         (setattrfunc)module_setattr, /*tp_setattr*/
 249         0,                      /*tp_compare*/
 250         (reprfunc)module_repr, /*tp_repr*/
 251 };