summaryrefslogtreecommitdiffstats
path: root/Python/modsupport.c
blob: dd7454cf9f4a303715c77b05c844b2e06a5bdfdf (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
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634

/* Module support implementation */

#include "Python.h"

#define FLAG_SIZE_T 1
typedef double va_double;

static PyObject *va_build_value(const char *, va_list, int);
#ifdef HAVE_DECLSPEC_DLL
PyAPI_FUNC(PyObject *) _Py_BuildValue_SizeT(const char *, ...);
#endif

/* Package context -- the full module name for package imports */
char *_Py_PackageContext = NULL;

/* Py_InitModule4() parameters:
   - name is the module name
   - methods is the list of top-level functions
   - doc is the documentation string
   - passthrough is passed as self to functions defined in the module
   - api_version is the value of PYTHON_API_VERSION at the time the
     module was compiled

   Return value is a borrowed reference to the module object; or NULL
   if an error occurred (in Python 1.4 and before, errors were fatal).
   Errors may still leak memory.
*/

static char api_version_warning[] =
"Python C API version mismatch for module %.100s:\
 This Python has API version %d, module %.100s has version %d.";

PyObject *
Py_InitModule4(const char *name, PyMethodDef *methods, const char *doc,
	       PyObject *passthrough, int module_api_version)
{
	PyObject *m, *d, *v, *n;
	PyMethodDef *ml;
	if (!Py_IsInitialized())
	    Py_FatalError("Interpreter not initialized (version mismatch?)");
	if (module_api_version != PYTHON_API_VERSION) {
		char message[512];
		PyOS_snprintf(message, sizeof(message), 
			      api_version_warning, name, 
			      PYTHON_API_VERSION, name, 
			      module_api_version);
		if (PyErr_Warn(PyExc_RuntimeWarning, message)) 
			return NULL;
	}
	/* Make sure name is fully qualified.

	   This is a bit of a hack: when the shared library is loaded,
	   the module name is "package.module", but the module calls
	   Py_InitModule*() with just "module" for the name.  The shared
	   library loader squirrels away the true name of the module in
	   _Py_PackageContext, and Py_InitModule*() will substitute this
	   (if the name actually matches).
	*/
	if (_Py_PackageContext != NULL) {
		char *p = strrchr(_Py_PackageContext, '.');
		if (p != NULL && strcmp(name, p+1) == 0) {
			name = _Py_PackageContext;
			_Py_PackageContext = NULL;
		}
	}
	if ((m = PyImport_AddModule(name)) == NULL)
		return NULL;
	d = PyModule_GetDict(m);
	if (methods != NULL) {
		n = PyString_FromString(name);
		if (n == NULL)
			return NULL;
		for (ml = methods; ml->ml_name != NULL; ml++) {
			if ((ml->ml_flags & METH_CLASS) ||
			    (ml->ml_flags & METH_STATIC)) {
				PyErr_SetString(PyExc_ValueError,
						"module functions cannot set"
						" METH_CLASS or METH_STATIC");
				Py_DECREF(n);
				return NULL;
			}
			v = PyCFunction_NewEx(ml, passthrough, n);
			if (v == NULL) {
				Py_DECREF(n);
				return NULL;
			}
			if (PyDict_SetItemString(d, ml->ml_name, v) != 0) {
				Py_DECREF(v);
				Py_DECREF(n);
				return NULL;
			}
			Py_DECREF(v);
		}
		Py_DECREF(n);
	}
	if (doc != NULL) {
		v = PyString_FromString(doc);
		if (v == NULL || PyDict_SetItemString(d, "__doc__", v) != 0) {
			Py_XDECREF(v);
			return NULL;
		}
		Py_DECREF(v);
	}
	return m;
}


/* Helper for mkvalue() to scan the length of a format */

static int
countformat(const char *format, int endchar)
{
	int count = 0;
	int level = 0;
	while (level > 0 || *format != endchar) {
		switch (*format) {
		case '\0':
			/* Premature end */
			PyErr_SetString(PyExc_SystemError,
					"unmatched paren in format");
			return -1;
		case '(':
		case '[':
		case '{':
			if (level == 0)
				count++;
			level++;
			break;
		case ')':
		case ']':
		case '}':
			level--;
			break;
		case '#':
		case '&':
		case ',':
		case ':':
		case ' ':
		case '\t':
			break;
		default:
			if (level == 0)
				count++;
		}
		format++;
	}
	return count;
}


/* Generic function to create a value -- the inverse of getargs() */
/* After an original idea and first implementation by Steven Miale */

static PyObject *do_mktuple(const char**, va_list *, int, int, int);
static PyObject *do_mklist(const char**, va_list *, int, int, int);
static PyObject *do_mkdict(const char**, va_list *, int, int, int);
static PyObject *do_mkvalue(const char**, va_list *, int);


static PyObject *
do_mkdict(const char **p_format, va_list *p_va, int endchar, int n, int flags)
{
	PyObject *d;
	int i;
	int itemfailed = 0;
	if (n < 0)
		return NULL;
	if ((d = PyDict_New()) == NULL)
		return NULL;
	/* Note that we can't bail immediately on error as this will leak
	   refcounts on any 'N' arguments. */
	for (i = 0; i < n; i+= 2) {
		PyObject *k, *v;
		int err;
		k = do_mkvalue(p_format, p_va, flags);
		if (k == NULL) {
			itemfailed = 1;
			Py_INCREF(Py_None);
			k = Py_None;
		}
		v = do_mkvalue(p_format, p_va, flags);
		if (v == NULL) {
			itemfailed = 1;
			Py_INCREF(Py_None);
			v = Py_None;
		}
		err = PyDict_SetItem(d, k, v);
		Py_DECREF(k);
		Py_DECREF(v);
		if (err < 0 || itemfailed) {
			Py_DECREF(d);
			return NULL;
		}
	}
	if (d != NULL && **p_format != endchar) {
		Py_DECREF(d);
		d = NULL;
		PyErr_SetString(PyExc_SystemError,
				"Unmatched paren in format");
	}
	else if (endchar)
		++*p_format;
	return d;
}

static PyObject *
do_mklist(const char **p_format, va_list *p_va, int endchar, int n, int flags)
{
	PyObject *v;
	int i;
	int itemfailed = 0;
	if (n < 0)
		return NULL;
	v = PyList_New(n);
	if (v == NULL)
		return NULL;
	/* Note that we can't bail immediately on error as this will leak
	   refcounts on any 'N' arguments. */
	for (i = 0; i < n; i++) {
		PyObject *w = do_mkvalue(p_format, p_va, flags);
		if (w == NULL) {
			itemfailed = 1;
			Py_INCREF(Py_None);
			w = Py_None;
		}
		PyList_SET_ITEM(v, i, w);
	}

	if (itemfailed) {
		/* do_mkvalue() should have already set an error */
		Py_DECREF(v);
		return NULL;
	}
	if (**p_format != endchar) {
		Py_DECREF(v);
		PyErr_SetString(PyExc_SystemError,
				"Unmatched paren in format");
		return NULL;
	}
	if (endchar)
		++*p_format;
	return v;
}

#ifdef Py_USING_UNICODE
static int
_ustrlen(Py_UNICODE *u)
{
	int i = 0;
	Py_UNICODE *v = u;
	while (*v != 0) { i++; v++; } 
	return i;
}
#endif

static PyObject *
do_mktuple(const char **p_format, va_list *p_va, int endchar, int n, int flags)
{
	PyObject *v;
	int i;
	int itemfailed = 0;
	if (n < 0)
		return NULL;
	if ((v = PyTuple_New(n)) == NULL)
		return NULL;
	/* Note that we can't bail immediately on error as this will leak
	   refcounts on any 'N' arguments. */
	for (i = 0; i < n; i++) {
		PyObject *w = do_mkvalue(p_format, p_va, flags);
		if (w == NULL) {
			itemfailed = 1;
			Py_INCREF(Py_None);
			w = Py_None;
		}
		PyTuple_SET_ITEM(v, i, w);
	}
	if (itemfailed) {
		/* do_mkvalue() should have already set an error */
		Py_DECREF(v);
		return NULL;
	}
	if (**p_format != endchar) {
		Py_DECREF(v);
		PyErr_SetString(PyExc_SystemError,
				"Unmatched paren in format");
		return NULL;
	}
	if (endchar)
		++*p_format;
	return v;
}

static PyObject *
do_mkvalue(const char **p_format, va_list *p_va, int flags)
{
	for (;;) {
		switch (*(*p_format)++) {
		case '(':
			return do_mktuple(p_format, p_va, ')',
					  countformat(*p_format, ')'), flags);

		case '[':
			return do_mklist(p_format, p_va, ']',
					 countformat(*p_format, ']'), flags);

		case '{':
			return do_mkdict(p_format, p_va, '}',
					 countformat(*p_format, '}'), flags);

		case 'b':
		case 'B':
		case 'h':
		case 'i':
			return PyInt_FromLong((long)va_arg(*p_va, int));
			
		case 'H':
			return PyInt_FromLong((long)va_arg(*p_va, unsigned int));

		case 'I':
		{
			unsigned int n;
			n = va_arg(*p_va, unsigned int);
			if (n > (unsigned long)PyInt_GetMax())
				return PyLong_FromUnsignedLong((unsigned long)n);
			else
				return PyInt_FromLong(n);
		}
		
		case 'n':
#if SIZEOF_SIZE_T!=SIZEOF_LONG
			return PyInt_FromSsize_t(va_arg(*p_va, Py_ssize_t));
#endif
			/* Fall through from 'n' to 'l' if Py_ssize_t is long */
		case 'l':
			return PyInt_FromLong(va_arg(*p_va, long));

		case 'k':
		{
			unsigned long n;
			n = va_arg(*p_va, unsigned long);
			if (n > (unsigned long)PyInt_GetMax())
				return PyLong_FromUnsignedLong(n);
			else
				return PyInt_FromLong(n);
		}

#ifdef HAVE_LONG_LONG
		case 'L':
			return PyLong_FromLongLong((PY_LONG_LONG)va_arg(*p_va, PY_LONG_LONG));

		case 'K':
			return PyLong_FromUnsignedLongLong((PY_LONG_LONG)va_arg(*p_va, unsigned PY_LONG_LONG));
#endif
#ifdef Py_USING_UNICODE
		case 'u':
		{
			PyObject *v;
			Py_UNICODE *u = va_arg(*p_va, Py_UNICODE *);
			Py_ssize_t n;	
			if (**p_format == '#') {
				++*p_format;
				if (flags & FLAG_SIZE_T)
					n = va_arg(*p_va, Py_ssize_t);
				else
					n = va_arg(*p_va, int);
			}
			else
				n = -1;
			if (u == NULL) {
				v = Py_None;
				Py_INCREF(v);
			}
			else {
				if (n < 0)
					n = _ustrlen(u);
				v = PyUnicode_FromUnicode(u, n);
			}
			return v;
		}
#endif
		case 'f':
		case 'd':
			return PyFloat_FromDouble(
				(double)va_arg(*p_va, va_double));

#ifndef WITHOUT_COMPLEX
		case 'D':
			return PyComplex_FromCComplex(
				*((Py_complex *)va_arg(*p_va, Py_complex *)));
#endif /* WITHOUT_COMPLEX */

		case 'c':
		{
			char p[1];
			p[0] = (char)va_arg(*p_va, int);
			return PyString_FromStringAndSize(p, 1);
		}

		case 's':
		case 'z':
		{
			PyObject *v;
			char *str = va_arg(*p_va, char *);
			Py_ssize_t n;
			if (**p_format == '#') {
				++*p_format;
				if (flags & FLAG_SIZE_T)
					n = va_arg(*p_va, Py_ssize_t);
				else
					n = va_arg(*p_va, int);
			}
			else
				n = -1;
			if (str == NULL) {
				v = Py_None;
				Py_INCREF(v);
			}
			else {
				if (n < 0) {
					size_t m = strlen(str);
					if (m > PY_SSIZE_T_MAX) {
						PyErr_SetString(PyExc_OverflowError,
							"string too long for Python string");
						return NULL;
					}
					n = (int)m;
				}
				v = PyString_FromStringAndSize(str, n);
			}
			return v;
		}

		case 'N':
		case 'S':
		case 'O':
		if (**p_format == '&') {
			typedef PyObject *(*converter)(void *);
			converter func = va_arg(*p_va, converter);
			void *arg = va_arg(*p_va, void *);
			++*p_format;
			return (*func)(arg);
		}
		else {
			PyObject *v;
			v = va_arg(*p_va, PyObject *);
			if (v != NULL) {
				if (*(*p_format - 1) != 'N')
					Py_INCREF(v);
			}
			else if (!PyErr_Occurred())
				/* If a NULL was passed
				 * because a call that should
				 * have constructed a value
				 * failed, that's OK, and we
				 * pass the error on; but if
				 * no error occurred it's not
				 * clear that the caller knew
				 * what she was doing. */
				PyErr_SetString(PyExc_SystemError,
					"NULL object passed to Py_BuildValue");
			return v;
		}

		case ':':
		case ',':
		case ' ':
		case '\t':
			break;

		default:
			PyErr_SetString(PyExc_SystemError,
				"bad format char passed to Py_BuildValue");
			return NULL;

		}
	}
}


PyObject *
Py_BuildValue(const char *format, ...)
{
	va_list va;
	PyObject* retval;
	va_start(va, format);
	retval = va_build_value(format, va, 0);
	va_end(va);
	return retval;
}

PyObject *
_Py_BuildValue_SizeT(const char *format, ...)
{
	va_list va;
	PyObject* retval;
	va_start(va, format);
	retval = va_build_value(format, va, FLAG_SIZE_T);
	va_end(va);
	return retval;
}

PyObject *
Py_VaBuildValue(const char *format, va_list va)
{
	return va_build_value(format, va, 0);
}

PyObject *
_Py_VaBuildValue_SizeT(const char *format, va_list va)
{
	return va_build_value(format, va, FLAG_SIZE_T);
}

static PyObject *
va_build_value(const char *format, va_list va, int flags)
{
	const char *f = format;
	int n = countformat(f, '\0');
	va_list lva;

#ifdef VA_LIST_IS_ARRAY
	memcpy(lva, va, sizeof(va_list));
#else
#ifdef __va_copy
	__va_copy(lva, va);
#else
	lva = va;
#endif
#endif

	if (n < 0)
		return NULL;
	if (n == 0) {
		Py_INCREF(Py_None);
		return Py_None;
	}
	if (n == 1)
		return do_mkvalue(&f, &lva, flags);
	return do_mktuple(&f, &lva, '\0', n, flags);
}


PyObject *
PyEval_CallFunction(PyObject *obj, const char *format, ...)
{
	va_list vargs;
	PyObject *args;
	PyObject *res;

	va_start(vargs, format);

	args = Py_VaBuildValue(format, vargs);
	va_end(vargs);

	if (args == NULL)
		return NULL;

	res = PyEval_CallObject(obj, args);
	Py_DECREF(args);

	return res;
}


PyObject *
PyEval_CallMethod(PyObject *obj, const char *methodname, const char *format, ...)
{
	va_list vargs;
	PyObject *meth;
	PyObject *args;
	PyObject *res;

	meth = PyObject_GetAttrString(obj, methodname);
	if (meth == NULL)
		return NULL;

	va_start(vargs, format);

	args = Py_VaBuildValue(format, vargs);
	va_end(vargs);

	if (args == NULL) {
		Py_DECREF(meth);
		return NULL;
	}

	res = PyEval_CallObject(meth, args);
	Py_DECREF(meth);
	Py_DECREF(args);

	return res;
}

int
PyModule_AddObject(PyObject *m, const char *name, PyObject *o)
{
	PyObject *dict;
	if (!PyModule_Check(m)) {
		PyErr_SetString(PyExc_TypeError,
			    "PyModule_AddObject() needs module as first arg");
		return -1;
	}
	if (!o) {
		if (!PyErr_Occurred())
			PyErr_SetString(PyExc_TypeError,
					"PyModule_AddObject() needs non-NULL value");
		return -1;
	}

	dict = PyModule_GetDict(m);
	if (dict == NULL) {
		/* Internal error -- modules must have a dict! */
		PyErr_Format(PyExc_SystemError, "module '%s' has no __dict__",
			     PyModule_GetName(m));
		return -1;
	}
	if (PyDict_SetItemString(dict, name, o))
		return -1;
	Py_DECREF(o);
	return 0;
}

int 
PyModule_AddIntConstant(PyObject *m, const char *name, long value)
{
	return PyModule_AddObject(m, name, PyInt_FromLong(value));
}

int 
PyModule_AddStringConstant(PyObject *m, const char *name, const char *value)
{
	return PyModule_AddObject(m, name, PyString_FromString(value));
}