summaryrefslogtreecommitdiffstats
path: root/Objects/moduleobject.c
blob: 4267896bf0241cc72cbd34296bb07cecbac726df (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226

/* Module object implementation */

#include "Python.h"

typedef struct {
	PyObject_HEAD
	PyObject *md_dict;
} PyModuleObject;

PyObject *
PyModule_New(char *name)
{
	PyModuleObject *m;
	PyObject *nameobj;
	m = PyObject_NEW(PyModuleObject, &PyModule_Type);
	if (m == NULL)
		return NULL;
	nameobj = PyString_FromString(name);
	m->md_dict = PyDict_New();
	if (m->md_dict == NULL || nameobj == NULL)
		goto fail;
	if (PyDict_SetItemString(m->md_dict, "__name__", nameobj) != 0)
		goto fail;
	if (PyDict_SetItemString(m->md_dict, "__doc__", Py_None) != 0)
		goto fail;
	Py_DECREF(nameobj);
	return (PyObject *)m;

 fail:
	Py_XDECREF(nameobj);
	Py_DECREF(m);
	return NULL;
}

PyObject *
PyModule_GetDict(PyObject *m)
{
	if (!PyModule_Check(m)) {
		PyErr_BadInternalCall();
		return NULL;
	}
	return ((PyModuleObject *)m) -> md_dict;
}

char *
PyModule_GetName(PyObject *m)
{
	PyObject *nameobj;
	if (!PyModule_Check(m)) {
		PyErr_BadArgument();
		return NULL;
	}
	nameobj = PyDict_GetItemString(((PyModuleObject *)m)->md_dict,
				       "__name__");
	if (nameobj == NULL || !PyString_Check(nameobj)) {
		PyErr_SetString(PyExc_SystemError, "nameless module");
		return NULL;
	}
	return PyString_AsString(nameobj);
}

char *
PyModule_GetFilename(PyObject *m)
{
	PyObject *fileobj;
	if (!PyModule_Check(m)) {
		PyErr_BadArgument();
		return NULL;
	}
	fileobj = PyDict_GetItemString(((PyModuleObject *)m)->md_dict,
				       "__file__");
	if (fileobj == NULL || !PyString_Check(fileobj)) {
		PyErr_SetString(PyExc_SystemError, "module filename missing");
		return NULL;
	}
	return PyString_AsString(fileobj);
}

void
_PyModule_Clear(PyObject *m)
{
	/* To make the execution order of destructors for global
	   objects a bit more predictable, we first zap all objects
	   whose name starts with a single underscore, before we clear
	   the entire dictionary.  We zap them by replacing them with
	   None, rather than deleting them from the dictionary, to
	   avoid rehashing the dictionary (to some extent). */

	int pos;
	PyObject *key, *value;
	PyObject *d;

	d = ((PyModuleObject *)m)->md_dict;

	/* First, clear only names starting with a single underscore */
	pos = 0;
	while (PyDict_Next(d, &pos, &key, &value)) {
		if (value != Py_None && PyString_Check(key)) {
			char *s = PyString_AsString(key);
			if (s[0] == '_' && s[1] != '_') {
				if (Py_VerboseFlag > 1)
				    PySys_WriteStderr("#   clear[1] %s\n", s);
				PyDict_SetItem(d, key, Py_None);
			}
		}
	}

	/* Next, clear all names except for __builtins__ */
	pos = 0;
	while (PyDict_Next(d, &pos, &key, &value)) {
		if (value != Py_None && PyString_Check(key)) {
			char *s = PyString_AsString(key);
			if (s[0] != '_' || strcmp(s, "__builtins__") != 0) {
				if (Py_VerboseFlag > 1)
				    PySys_WriteStderr("#   clear[2] %s\n", s);
				PyDict_SetItem(d, key, Py_None);
			}
		}
	}

	/* Note: we leave __builtins__ in place, so that destructors
	   of non-global objects defined in this module can still use
	   builtins, in particularly 'None'. */

}

/* Methods */

static void
module_dealloc(PyModuleObject *m)
{
	if (m->md_dict != NULL) {
		_PyModule_Clear((PyObject *)m);
		Py_DECREF(m->md_dict);
	}
	PyObject_DEL(m);
}

static PyObject *
module_repr(PyModuleObject *m)
{
	char buf[400];
	char *name;
	char *filename;
	name = PyModule_GetName((PyObject *)m);
	if (name == NULL) {
		PyErr_Clear();
		name = "?";
	}
	filename = PyModule_GetFilename((PyObject *)m);
	if (filename == NULL) {
		PyErr_Clear();
		sprintf(buf, "<module '%.80s' (built-in)>", name);
	} else {
		sprintf(buf, "<module '%.80s' from '%.255s'>", name, filename);
	}

	return PyString_FromString(buf);
}

static PyObject *
module_getattr(PyModuleObject *m, char *name)
{
	PyObject *res;
	char* modname;
	if (strcmp(name, "__dict__") == 0) {
		Py_INCREF(m->md_dict);
		return m->md_dict;
	}
	res = PyDict_GetItemString(m->md_dict, name);
	if (res == NULL) {
		modname = PyModule_GetName((PyObject *)m);
		if (modname == NULL) {
			PyErr_Clear();
			modname = "?";
		}
		PyErr_Format(PyExc_AttributeError,
			     "'%.50s' module has no attribute '%.400s'",
			     modname, name);
	}
	else
		Py_INCREF(res);
	return res;
}

static int
module_setattr(PyModuleObject *m, char *name, PyObject *v)
{
	char* modname;
	if (name[0] == '_' && strcmp(name, "__dict__") == 0) {
		PyErr_SetString(PyExc_TypeError,
				"read-only special attribute");
		return -1;
	}
	if (v == NULL) {
		int rv = PyDict_DelItemString(m->md_dict, name);
		if (rv < 0) {
			modname = PyModule_GetName((PyObject *)m);
			if (modname == NULL) {
				PyErr_Clear();
				modname = "?";
			}
			PyErr_Format(PyExc_AttributeError,
				     "'%.50s' module has no attribute '%.400s'",
				     modname, name);
		}
		return rv;
	}
	else
		return PyDict_SetItemString(m->md_dict, name, v);
}

PyTypeObject PyModule_Type = {
	PyObject_HEAD_INIT(&PyType_Type)
	0,			/*ob_size*/
	"module",		/*tp_name*/
	sizeof(PyModuleObject),	/*tp_size*/
	0,			/*tp_itemsize*/
	(destructor)module_dealloc, /*tp_dealloc*/
	0,			/*tp_print*/
	(getattrfunc)module_getattr, /*tp_getattr*/
	(setattrfunc)module_setattr, /*tp_setattr*/
	0,			/*tp_compare*/
	(reprfunc)module_repr, /*tp_repr*/
};