summaryrefslogtreecommitdiffstats
path: root/Python/import.c
blob: 44f6d7bdceb2756a6e5824aca349bb98eaa4dec3 (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
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
/***********************************************************
Copyright 1991, 1992 by Stichting Mathematisch Centrum, Amsterdam, The
Netherlands.

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its 
documentation for any purpose and without fee is hereby granted, 
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in 
supporting documentation, and that the names of Stichting Mathematisch
Centrum or CWI not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior permission.

STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO
THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE
FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

******************************************************************/

/* Module definition and import implementation */

#include "allobjects.h"

#include "node.h"
#include "token.h"
#include "graminit.h"
#include "import.h"
#include "errcode.h"
#include "sysmodule.h"
#include "pythonrun.h"
#include "marshal.h"
#include "compile.h"
#include "eval.h"
#include "osdefs.h"

extern int verbose; /* Defined in pythonmain.c */

#ifdef DEBUG
#define D(x) x
#else
#define D(x)
#endif

#ifdef USE_DL
#include "dl.h"

extern char *argv0;
#endif

/* Magic word to reject pre-0.9.4 .pyc files */

#define MAGIC 0x949494L

static object *modules;

/* Forward */
static int init_builtin PROTO((char *));

/* Initialization */

void
initimport()
{
	if ((modules = newdictobject()) == NULL)
		fatal("no mem for dictionary of modules");
}

object *
get_modules()
{
	return modules;
}

object *
add_module(name)
	char *name;
{
	object *m;
	if ((m = dictlookup(modules, name)) != NULL && is_moduleobject(m))
		return m;
	m = newmoduleobject(name);
	if (m == NULL)
		return NULL;
	if (dictinsert(modules, name, m) != 0) {
		DECREF(m);
		return NULL;
	}
	DECREF(m); /* Yes, it still exists, in modules! */
	return m;
}

/* Suffixes used by open_module: */

#define PY_SUFFIX	".py"
#ifdef USE_DL
#define O_SUFFIX	"module.o"
#endif

/* Find and open a module file, using sys.path.
   Return a NULL pointer if no module file is found.
   When dynamic loading is enabled, the contents of namebuf
   is important when NULL is returned: if namebuf[0] != '\0'
   a dl-able object file was found and namebuf is its pathname. */

static FILE *
open_module(name, namebuf)
	char *name;
	char *namebuf; /* XXX No buffer overflow checks! */
{
	object *path;
	FILE *fp;
	
	path = sysget("path");
	if (path == NULL || !is_listobject(path)) {
		/* No path -- at least try current directory */
#ifdef USE_DL
		strcpy(namebuf, name);
		strcat(namebuf, O_SUFFIX);
		if (getmtime(namebuf) > 0)
			return NULL;
#endif
		strcpy(namebuf, name);
		strcat(namebuf, PY_SUFFIX);
		fp = fopen(namebuf, "r");
	}
	else {
		int npath = getlistsize(path);
		int i;
		fp = NULL;
		for (i = 0; i < npath; i++) {
			object *v = getlistitem(path, i);
			int len;
			if (!is_stringobject(v))
				continue;
			strcpy(namebuf, getstringvalue(v));
			len = getstringsize(v);
			if (len > 0 && namebuf[len-1] != SEP)
				namebuf[len++] = SEP;
#ifdef USE_DL
			strcpy(namebuf+len, name);
			strcat(namebuf, O_SUFFIX);
			if (getmtime(namebuf) > 0)
				return NULL;
#endif
			strcpy(namebuf+len, name);
			strcat(namebuf, PY_SUFFIX);
			fp = fopen(namebuf, "r");
			if (fp != NULL)
				break;
		}
	}
	if (fp == NULL)
		namebuf[0] = '\0';
	return fp;
}

static object *
get_module(m, name, m_ret)
	/*module*/object *m;
	char *name;
	object **m_ret;
{
	codeobject *co = NULL;
	object *v, *d;
	FILE *fp, *fpc;
	node *n;
	int err;
	char namebuf[MAXPATHLEN+1];
	int namelen;
	long mtime;
	extern long getmtime();
	
	fp = open_module(name, namebuf);
	if (fp == NULL) {
#ifdef USE_DL
		if (namebuf[0] != '\0') {
			char funcname[258];
			dl_funcptr p;
			D(fprintf(stderr, "Found %s\n", namebuf));
			sprintf(funcname, "init%s", name);
			p =  dl_loadmod(argv0, namebuf, funcname);
			if (p == NULL) {
				D(fprintf(stderr, "dl_loadmod failed\n"));
			}
			else {
				if (verbose)
					fprintf(stderr,
				"import %s # dynamically loaded from \"%s\"\n",
						name, namebuf);
				(*p)();
				*m_ret = m = dictlookup(modules, name);
				if (m == NULL) {
					err_setstr(SystemError,
						   "dynamic module missing");
					return NULL;
				}
				else {
					D(fprintf(stderr,
						"module %s loaded!\n", name));
					INCREF(None);
					return None;
				}
			}
		}
#endif
		if (m == NULL) {
			sprintf(namebuf, "no module named %.200s", name);
			err_setstr(ImportError, namebuf);
		}
		else {
			sprintf(namebuf, "no source for module %.200s", name);
			err_setstr(ImportError, namebuf);
		}
		return NULL;
	}
	/* Get mtime -- always useful */
	mtime = getmtime(namebuf);
	/* Check ".pyc" file first */
	namelen = strlen(namebuf);
	namebuf[namelen] = 'c';
	namebuf[namelen+1] = '\0';
	fpc = fopen(namebuf, "rb");
	if (fpc != NULL) {
		long pyc_mtime;
		long magic;
		magic = rd_long(fpc);
		pyc_mtime = rd_long(fpc);
		if (magic == MAGIC && pyc_mtime == mtime && mtime != 0 && mtime != -1) {
			v = rd_object(fpc);
			if (v == NULL || err_occurred() || !is_codeobject(v)) {
				err_clear();
				XDECREF(v);
			}
			else
				co = (codeobject *)v;
		}
		fclose(fpc);
		if (verbose) {
			if (co != NULL)
				fprintf(stderr,
				"import %s # precompiled from \"%s\"\n",
					name, namebuf);
			else
				fprintf(stderr,
					"# invalid precompiled file \"%s\"\n",
					namebuf);
		}
	}
	namebuf[namelen] = '\0';
	if (co == NULL) {
		if (verbose)
			fprintf(stderr,
				"import %s # from \"%s\"\n",
				name, namebuf);
		err = parse_file(fp, namebuf, file_input, &n);
	}
	else
		err = E_DONE;
	fclose(fp);
	if (err != E_DONE) {
		err_input(err);
		return NULL;
	}
	if (m == NULL) {
		m = add_module(name);
		if (m == NULL) {
			freetree(n);
			return NULL;
		}
		*m_ret = m;
	}
	d = getmoduledict(m);
	if (co == NULL) {
		co = compile(n, namebuf);
		freetree(n);
		if (co == NULL)
			return NULL;
		/* Now write the code object to the ".pyc" file */
		namebuf[namelen] = 'c';
		namebuf[namelen+1] = '\0';
		fpc = fopen(namebuf, "wb");
		if (fpc != NULL) {
			wr_long(MAGIC, fpc);
			/* First write a 0 for mtime */
			wr_long(0L, fpc);
			wr_object((object *)co, fpc);
			if (ferror(fpc)) {
				/* Don't keep partial file */
				fclose(fpc);
				(void) unlink(namebuf);
			}
			else {
				/* Now write the true mtime */
				fseek(fpc, 4L, 0);
				wr_long(mtime, fpc);
				fflush(fpc);
				fclose(fpc);
			}
		}
	}
	v = eval_code(co, d, d, (object *)NULL);
	DECREF(co);
	return v;
}

static object *
load_module(name)
	char *name;
{
	object *m, *v;
	v = get_module((object *)NULL, name, &m);
	if (v == NULL)
		return NULL;
	DECREF(v);
	return m;
}

object *
import_module(name)
	char *name;
{
	object *m;
	if ((m = dictlookup(modules, name)) == NULL) {
		if (init_builtin(name)) {
			if ((m = dictlookup(modules, name)) == NULL)
				err_setstr(SystemError,
					   "builtin module missing");
		}
		else {
			m = load_module(name);
		}
	}
	return m;
}

object *
reload_module(m)
	object *m;
{
	if (m == NULL || !is_moduleobject(m)) {
		err_setstr(TypeError, "reload() argument must be module");
		return NULL;
	}
	/* XXX Ought to check for builtin modules -- can't reload these... */
	return get_module(m, getmodulename(m), (object **)NULL);
}

static void
cleardict(d)
	object *d;
{
	int i;
	for (i = getdictsize(d); --i >= 0; ) {
		char *k;
		k = getdictkey(d, i);
		if (k != NULL)
			(void) dictremove(d, k);
	}
}

void
doneimport()
{
	if (modules != NULL) {
		int i;
		/* Explicitly erase all modules; this is the safest way
		   to get rid of at least *some* circular dependencies */
		for (i = getdictsize(modules); --i >= 0; ) {
			object *k;
			k = getdict2key(modules, i);
			if (k != NULL) {
				object *m;
				m = dict2lookup(modules, k);
				if (m == NULL)
					err_clear();
				else if (is_moduleobject(m)) {
					object *d;
					d = getmoduledict(m);
					if (d != NULL && is_dictobject(d)) {
						cleardict(d);
					}
				}
			}
		}
		cleardict(modules);
	}
	DECREF(modules);
}


/* Initialize built-in modules when first imported */

extern struct {
	char *name;
	void (*initfunc)();
} inittab[];

static int
init_builtin(name)
	char *name;
{
	int i;
	for (i = 0; inittab[i].name != NULL; i++) {
		if (strcmp(name, inittab[i].name) == 0) {
			if (verbose)
				fprintf(stderr, "import %s # builtin\n",
					name);
			(*inittab[i].initfunc)();
			return 1;
		}
	}
	return 0;
}