{{ message }}
Repository navigation
Expand file tree
/
Copy pathcrossinterp.c
More file actions
3356 lines (3003 loc) · 91.4 KB
/
Copy pathcrossinterp.c
File metadata and controls
3356 lines (3003 loc) · 91.4 KB
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
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/* API for managing interactions between isolated interpreters */
#include "Python.h"
#include "marshal.h" // PyMarshal_WriteObjectToString()
#include "osdefs.h" // MAXPATHLEN
#include "pycore_ceval.h" // _Py_simple_func
#include "pycore_crossinterp.h" // _PyXIData_t
#include "pycore_function.h" // _PyFunction_VerifyStateless()
#include "pycore_global_strings.h" // _Py_ID()
#include "pycore_import.h" // _PyImport_SetModule()
#include "pycore_initconfig.h" // _PyStatus_OK()
#include "pycore_namespace.h" // _PyNamespace_New()
#include "pycore_pythonrun.h" // _Py_SourceAsString()
#include "pycore_runtime.h" // _PyRuntime
#include "pycore_setobject.h" // _PySet_NextEntry()
#include "pycore_typeobject.h" // _PyStaticType_InitBuiltin()
static Py_ssize_t
_Py_GetMainfile(char *buffer, size_t maxlen)
{
// We don't expect subinterpreters to have the __main__ module's
// __name__ set, but proceed just in case.
PyThreadState *tstate = _PyThreadState_GET();
PyObject *module = _Py_GetMainModule(tstate);
if (_Py_CheckMainModule(module) < 0) {
Py_XDECREF(module);
return -1;
}
Py_ssize_t size = _PyModule_GetFilenameUTF8(module, buffer, maxlen);
Py_DECREF(module);
return size;
}
static PyObject *
runpy_run_path(const char *filename, const char *modname)
{
PyObject *run_path = PyImport_ImportModuleAttrString("runpy", "run_path");
if (run_path == NULL) {
return NULL;
}
PyObject *args = Py_BuildValue("(sOs)", filename, Py_None, modname);
if (args == NULL) {
Py_DECREF(run_path);
return NULL;
}
PyObject *ns = PyObject_Call(run_path, args, NULL);
Py_DECREF(run_path);
Py_DECREF(args);
return ns;
}
static void
set_exc_with_cause(PyObject *exctype, const char *msg)
{
PyObject *cause = PyErr_GetRaisedException();
PyErr_SetString(exctype, msg);
PyObject *exc = PyErr_GetRaisedException();
PyException_SetCause(exc, cause);
PyErr_SetRaisedException(exc);
}
/****************************/
/* module duplication utils */
/****************************/
struct sync_module_result {
PyObject *module;
PyObject *loaded;
PyObject *failed;
};
struct sync_module {
const char *filename;
char _filename[MAXPATHLEN+1];
struct sync_module_result cached;
};
static void
sync_module_clear(struct sync_module *data)
{
data->filename = NULL;
Py_CLEAR(data->cached.module);
Py_CLEAR(data->cached.loaded);
Py_CLEAR(data->cached.failed);
}
static void
sync_module_capture_exc(PyThreadState *tstate, struct sync_module *data)
{
assert(_PyErr_Occurred(tstate));
PyObject *context = data->cached.failed;
PyObject *exc = _PyErr_GetRaisedException(tstate);
_PyErr_SetRaisedException(tstate, Py_NewRef(exc));
if (context != NULL) {
PyException_SetContext(exc, context);
}
data->cached.failed = exc;
}
static int
ensure_isolated_main(PyThreadState *tstate, struct sync_module *main)
{
// Load the module from the original file (or from a cache).
// First try the local cache.
if (main->cached.failed != NULL) {
// We'll deal with this in apply_isolated_main().
assert(main->cached.module == NULL);
assert(main->cached.loaded == NULL);
return 0;
}
else if (main->cached.loaded != NULL) {
assert(main->cached.module != NULL);
return 0;
}
assert(main->cached.module == NULL);
if (main->filename == NULL) {
_PyErr_SetString(tstate, PyExc_NotImplementedError, "");
return -1;
}
// It wasn't in the local cache so we'll need to populate it.
PyObject *mod = _Py_GetMainModule(tstate);
if (_Py_CheckMainModule(mod) < 0) {
// This is probably unrecoverable, so don't bother caching the error.
assert(_PyErr_Occurred(tstate));
Py_XDECREF(mod);
return -1;
}
PyObject *loaded = NULL;
// Try the per-interpreter cache for the loaded module.
// XXX Store it in sys.modules?
PyObject *interpns = PyInterpreterState_GetDict(tstate->interp);
assert(interpns != NULL);
PyObject *key = PyUnicode_FromString("CACHED_MODULE_NS___main__");
if (key == NULL) {
// It's probably unrecoverable, so don't bother caching the error.
Py_DECREF(mod);
return -1;
}
else if (PyDict_GetItemRef(interpns, key, &loaded) < 0) {
// It's probably unrecoverable, so don't bother caching the error.
Py_DECREF(mod);
Py_DECREF(key);
return -1;
}
else if (loaded == NULL) {
// It wasn't already loaded from file.
loaded = PyModule_NewObject(&_Py_ID(__main__));
if (loaded == NULL) {
goto error;
}
PyObject *ns = _PyModule_GetDict(loaded);
// We don't want to trigger "if __name__ == '__main__':",
// so we use a bogus module name.
PyObject *loaded_ns =
runpy_run_path(main->filename, "<fake __main__>");
if (loaded_ns == NULL) {
goto error;
}
int res = PyDict_Update(ns, loaded_ns);
Py_DECREF(loaded_ns);
if (res < 0) {
goto error;
}
// Set the per-interpreter cache entry.
if (PyDict_SetItem(interpns, key, loaded) < 0) {
goto error;
}
}
Py_DECREF(key);
main->cached = (struct sync_module_result){
.module = mod,
.loaded = loaded,
};
return 0;
error:
sync_module_capture_exc(tstate, main);
Py_XDECREF(loaded);
Py_DECREF(mod);
Py_XDECREF(key);
return -1;
}
#ifndef NDEBUG
static int
main_mod_matches(PyObject *expected)
{
PyObject *mod = PyImport_GetModule(&_Py_ID(__main__));
Py_XDECREF(mod);
return mod == expected;
}
#endif
static int
apply_isolated_main(PyThreadState *tstate, struct sync_module *main)
{
assert((main->cached.loaded == NULL) == (main->cached.loaded == NULL));
if (main->cached.failed != NULL) {
// It must have failed previously.
assert(main->cached.loaded == NULL);
_PyErr_SetRaisedException(tstate, main->cached.failed);
return -1;
}
assert(main->cached.loaded != NULL);
assert(main_mod_matches(main->cached.module));
if (_PyImport_SetModule(&_Py_ID(__main__), main->cached.loaded) < 0) {
sync_module_capture_exc(tstate, main);
return -1;
}
return 0;
}
static void
restore_main(PyThreadState *tstate, struct sync_module *main)
{
assert(main->cached.failed == NULL);
assert(main->cached.module != NULL);
assert(main->cached.loaded != NULL);
PyObject *exc = _PyErr_GetRaisedException(tstate);
assert(main_mod_matches(main->cached.loaded));
int res = _PyImport_SetModule(&_Py_ID(__main__), main->cached.module);
assert(res == 0);
if (res < 0) {
PyErr_FormatUnraisable("Exception ignored while restoring __main__");
}
_PyErr_SetRaisedException(tstate, exc);
}
/**************/
/* exceptions */
/**************/
typedef struct xi_exceptions exceptions_t;
static int init_static_exctypes(exceptions_t *, PyInterpreterState *);
static void fini_static_exctypes(exceptions_t *, PyInterpreterState *);
static int init_heap_exctypes(exceptions_t *);
static void fini_heap_exctypes(exceptions_t *);
#include "crossinterp_exceptions.h"
/***************************/
/* cross-interpreter calls */
/***************************/
int
_Py_CallInInterpreter(PyInterpreterState *interp,
_Py_simple_func func, void *arg)
{
if (interp == PyInterpreterState_Get()) {
return func(arg);
}
// XXX Emit a warning if this fails?
_PyEval_AddPendingCall(interp, (_Py_pending_call_func)func, arg, 0);
return 0;
}
int
_Py_CallInInterpreterAndRawFree(PyInterpreterState *interp,
_Py_simple_func func, void *arg)
{
if (interp == PyInterpreterState_Get()) {
int res = func(arg);
PyMem_RawFree(arg);
return res;
}
// XXX Emit a warning if this fails?
_PyEval_AddPendingCall(interp, func, arg, _Py_PENDING_RAWFREE);
return 0;
}
/**************************/
/* cross-interpreter data */
/**************************/
/* registry of {type -> _PyXIData_getdata_t} */
/* For now we use a global registry of shareable classes.
An alternative would be to add a tp_* slot for a class's
_PyXIData_getdata_t. It would be simpler and more efficient. */
static void xid_lookup_init(_PyXIData_lookup_t *);
static void xid_lookup_fini(_PyXIData_lookup_t *);
struct _dlcontext;
static _PyXIData_getdata_t lookup_getdata(struct _dlcontext *, PyObject *);
#include "crossinterp_data_lookup.h"
/* lifecycle */
_PyXIData_t *
_PyXIData_New(void)
{
_PyXIData_t *xid = PyMem_RawCalloc(1, sizeof(_PyXIData_t));
if (xid == NULL) {
PyErr_NoMemory();
}
return xid;
}
void
_PyXIData_Free(_PyXIData_t *xid)
{
PyInterpreterState *interp = PyInterpreterState_Get();
_PyXIData_Clear(interp, xid);
PyMem_RawFree(xid);
}
/* defining cross-interpreter data */
static inline void
_xidata_init(_PyXIData_t *xidata)
{
// If the value is being reused
// then _xidata_clear() should have been called already.
assert(xidata->data == NULL);
assert(xidata->obj == NULL);
*xidata = (_PyXIData_t){0};
_PyXIData_INTERPID(xidata) = -1;
}
static inline void
_xidata_clear(_PyXIData_t *xidata)
{
// _PyXIData_t only has two members that need to be
// cleaned up, if set: "xidata" must be freed and "obj" must be decref'ed.
// In both cases the original (owning) interpreter must be used,
// which is the caller's responsibility to ensure.
if (xidata->data != NULL) {
if (xidata->free != NULL) {
xidata->free(xidata->data);
}
xidata->data = NULL;
}
Py_CLEAR(xidata->obj);
}
void
_PyXIData_Init(_PyXIData_t *xidata,
PyInterpreterState *interp,
void *shared, PyObject *obj,
xid_newobjfunc new_object)
{
assert(xidata != NULL);
assert(new_object != NULL);
_xidata_init(xidata);
xidata->data = shared;
if (obj != NULL) {
assert(interp != NULL);
// released in _PyXIData_Clear()
xidata->obj = Py_NewRef(obj);
}
// Ideally every object would know its owning interpreter.
// Until then, we have to rely on the caller to identify it
// (but we don't need it in all cases).
_PyXIData_INTERPID(xidata) = (interp != NULL)
? PyInterpreterState_GetID(interp)
: -1;
xidata->new_object = new_object;
}
int
_PyXIData_InitWithSize(_PyXIData_t *xidata,
PyInterpreterState *interp,
const size_t size, PyObject *obj,
xid_newobjfunc new_object)
{
assert(size > 0);
// For now we always free the shared data in the same interpreter
// where it was allocated, so the interpreter is required.
assert(interp != NULL);
_PyXIData_Init(xidata, interp, NULL, obj, new_object);
xidata->data = PyMem_RawCalloc(1, size);
if (xidata->data == NULL) {
return -1;
}
xidata->free = PyMem_RawFree;
return 0;
}
void
_PyXIData_Clear(PyInterpreterState *interp, _PyXIData_t *xidata)
{
assert(xidata != NULL);
// This must be called in the owning interpreter.
assert(interp == NULL
|| _PyXIData_INTERPID(xidata) == -1
|| _PyXIData_INTERPID(xidata) == PyInterpreterState_GetID(interp));
_xidata_clear(xidata);
}
/* getting cross-interpreter data */
static inline void
_set_xid_lookup_failure(PyThreadState *tstate, PyObject *obj, const char *msg,
PyObject *cause)
{
if (msg != NULL) {
assert(obj == NULL);
set_notshareableerror(tstate, cause, 0, msg);
}
else if (obj == NULL) {
msg = "object does not support cross-interpreter data";
set_notshareableerror(tstate, cause, 0, msg);
}
else {
msg = "%R does not support cross-interpreter data";
format_notshareableerror(tstate, cause, 0, msg, obj);
}
}
int
_PyObject_CheckXIData(PyThreadState *tstate, PyObject *obj)
{
dlcontext_t ctx;
if (get_lookup_context(tstate, &ctx) < 0) {
return -1;
}
_PyXIData_getdata_t getdata = lookup_getdata(&ctx, obj);
if (getdata.basic == NULL && getdata.fallback == NULL) {
if (!_PyErr_Occurred(tstate)) {
_set_xid_lookup_failure(tstate, obj, NULL, NULL);
}
return -1;
}
return 0;
}
static int
_check_xidata(PyThreadState *tstate, _PyXIData_t *xidata)
{
// xidata->data can be anything, including NULL, so we don't check it.
// xidata->obj may be NULL, so we don't check it.
if (_PyXIData_INTERPID(xidata) < 0) {
PyErr_SetString(PyExc_SystemError, "missing interp");
return -1;
}
if (xidata->new_object == NULL) {
PyErr_SetString(PyExc_SystemError, "missing new_object func");
return -1;
}
// xidata->free may be NULL, so we don't check it.
return 0;
}
static int
_get_xidata(PyThreadState *tstate,
PyObject *obj, xidata_fallback_t fallback, _PyXIData_t *xidata)
{
PyInterpreterState *interp = tstate->interp;
assert(xidata->data == NULL);
assert(xidata->obj == NULL);
if (xidata->data != NULL || xidata->obj != NULL) {
_PyErr_SetString(tstate, PyExc_ValueError, "xidata not cleared");
return -1;
}
// Call the "getdata" func for the object.
dlcontext_t ctx;
if (get_lookup_context(tstate, &ctx) < 0) {
return -1;
}
Py_INCREF(obj);
_PyXIData_getdata_t getdata = lookup_getdata(&ctx, obj);
if (getdata.basic == NULL && getdata.fallback == NULL) {
if (PyErr_Occurred()) {
Py_DECREF(obj);
return -1;
}
// Fall back to obj
Py_DECREF(obj);
if (!_PyErr_Occurred(tstate)) {
_set_xid_lookup_failure(tstate, obj, NULL, NULL);
}
return -1;
}
int res = getdata.basic != NULL
? getdata.basic(tstate, obj, xidata)
: getdata.fallback(tstate, obj, fallback, xidata);
Py_DECREF(obj);
if (res != 0) {
PyObject *cause = _PyErr_GetRaisedException(tstate);
assert(cause != NULL);
_set_xid_lookup_failure(tstate, obj, NULL, cause);
Py_XDECREF(cause);
return -1;
}
// Fill in the blanks and validate the result.
_PyXIData_INTERPID(xidata) = PyInterpreterState_GetID(interp);
if (_check_xidata(tstate, xidata) != 0) {
(void)_PyXIData_Release(xidata);
return -1;
}
return 0;
}
int
_PyObject_GetXIDataNoFallback(PyThreadState *tstate,
PyObject *obj, _PyXIData_t *xidata)
{
return _get_xidata(tstate, obj, _PyXIDATA_XIDATA_ONLY, xidata);
}
int
_PyObject_GetXIData(PyThreadState *tstate,
PyObject *obj, xidata_fallback_t fallback,
_PyXIData_t *xidata)
{
switch (fallback) {
case _PyXIDATA_XIDATA_ONLY:
return _get_xidata(tstate, obj, fallback, xidata);
case _PyXIDATA_FULL_FALLBACK:
if (_get_xidata(tstate, obj, fallback, xidata) == 0) {
return 0;
}
PyObject *exc = _PyErr_GetRaisedException(tstate);
if (PyFunction_Check(obj)) {
if (_PyFunction_GetXIData(tstate, obj, xidata) == 0) {
Py_DECREF(exc);
return 0;
}
_PyErr_Clear(tstate);
}
// We could try _PyMarshal_GetXIData() but we won't for now.
if (_PyPickle_GetXIData(tstate, obj, xidata) == 0) {
Py_DECREF(exc);
return 0;
}
// Raise the original exception.
_PyErr_SetRaisedException(tstate, exc);
return -1;
default:
#ifdef Py_DEBUG
Py_FatalError("unsupported xidata fallback option");
#endif
_PyErr_SetString(tstate, PyExc_SystemError,
"unsupported xidata fallback option");
return -1;
}
}
/* pickle C-API */
/* Per-interpreter cache for pickle.dumps and pickle.loads.
*
* Each interpreter has its own cache in _PyXI_state_t.pickle, preserving
* interpreter isolation. The cache is populated lazily on first use and
* cleared during interpreter finalization in _Py_xi_state_fini().
*
* Note: the cached references are captured at first use and not invalidated
* on module reload. This matches the caching pattern used elsewhere in
* CPython (e.g. arraymodule.c, _decimal.c). */
static PyObject *
_get_pickle_dumps(PyThreadState *tstate)
{
_PyXI_state_t *state = _PyXI_GET_STATE(tstate->interp);
PyObject *dumps = state->pickle.dumps;
if (dumps != NULL) {
return dumps;
}
dumps = PyImport_ImportModuleAttrString("pickle", "dumps");
if (dumps == NULL) {
return NULL;
}
state->pickle.dumps = dumps; // owns the reference
return dumps;
}
static PyObject *
_get_pickle_loads(PyThreadState *tstate)
{
_PyXI_state_t *state = _PyXI_GET_STATE(tstate->interp);
PyObject *loads = state->pickle.loads;
if (loads != NULL) {
return loads;
}
loads = PyImport_ImportModuleAttrString("pickle", "loads");
if (loads == NULL) {
return NULL;
}
state->pickle.loads = loads; // owns the reference
return loads;
}
struct _pickle_context {
PyThreadState *tstate;
};
static PyObject *
_PyPickle_Dumps(struct _pickle_context *ctx, PyObject *obj)
{
PyObject *dumps = _get_pickle_dumps(ctx->tstate);
if (dumps == NULL) {
return NULL;
}
// dumps is a borrowed reference from the cache.
return PyObject_CallOneArg(dumps, obj);
}
struct _unpickle_context {
PyThreadState *tstate;
// We only special-case the __main__ module,
// since other modules behave consistently.
struct sync_module main;
};
static void
_unpickle_context_clear(struct _unpickle_context *ctx)
{
sync_module_clear(&ctx->main);
}
static int
check_missing___main___attr(PyObject *exc)
{
assert(!PyErr_Occurred());
if (!PyErr_GivenExceptionMatches(exc, PyExc_AttributeError)) {
return 0;
}
// Get the error message.
PyObject *args = PyException_GetArgs(exc);
if (args == NULL || args == Py_None || PyObject_Size(args) < 1) {
Py_XDECREF(args);
assert(!PyErr_Occurred());
return 0;
}
PyObject *msgobj = args;
if (!PyUnicode_Check(msgobj)) {
msgobj = PySequence_GetItem(args, 0);
Py_DECREF(args);
if (msgobj == NULL) {
PyErr_Clear();
return 0;
}
}
const char *err = PyUnicode_AsUTF8(msgobj);
// Check if it's a missing __main__ attr.
int cmp = strncmp(err, "module '__main__' has no attribute '", 36);
Py_DECREF(msgobj);
return cmp == 0;
}
static PyObject *
_PyPickle_Loads(struct _unpickle_context *ctx, PyObject *pickled)
{
PyThreadState *tstate = ctx->tstate;
PyObject *exc = NULL;
// loads is a borrowed reference from the per-interpreter cache.
PyObject *loads = _get_pickle_loads(tstate);
if (loads == NULL) {
return NULL;
}
// Make an initial attempt to unpickle.
PyObject *obj = PyObject_CallOneArg(loads, pickled);
if (obj != NULL) {
goto finally;
}
assert(_PyErr_Occurred(tstate));
if (ctx == NULL) {
goto finally;
}
exc = _PyErr_GetRaisedException(tstate);
if (!check_missing___main___attr(exc)) {
goto finally;
}
// Temporarily swap in a fake __main__ loaded from the original
// file and cached. Note that functions will use the cached ns
// for __globals__, // not the actual module.
if (ensure_isolated_main(tstate, &ctx->main) < 0) {
goto finally;
}
if (apply_isolated_main(tstate, &ctx->main) < 0) {
goto finally;
}
// Try to unpickle once more.
obj = PyObject_CallOneArg(loads, pickled);
restore_main(tstate, &ctx->main);
if (obj == NULL) {
goto finally;
}
Py_CLEAR(exc);
finally:
if (exc != NULL) {
if (_PyErr_Occurred(tstate)) {
sync_module_capture_exc(tstate, &ctx->main);
}
// We restore the original exception.
// It might make sense to chain it (__context__).
_PyErr_SetRaisedException(tstate, exc);
}
return obj;
}
/* pickle wrapper */
struct _pickle_xid_context {
// __main__.__file__
struct {
const char *utf8;
size_t len;
char _utf8[MAXPATHLEN+1];
} mainfile;
};
static int
_set_pickle_xid_context(PyThreadState *tstate, struct _pickle_xid_context *ctx)
{
// Set mainfile if possible.
Py_ssize_t len = _Py_GetMainfile(ctx->mainfile._utf8, MAXPATHLEN);
if (len < 0) {
// For now we ignore any exceptions.
PyErr_Clear();
}
else if (len > 0) {
ctx->mainfile.utf8 = ctx->mainfile._utf8;
ctx->mainfile.len = (size_t)len;
}
return 0;
}
struct _shared_pickle_data {
_PyBytes_data_t pickled; // Must be first if we use _PyBytes_FromXIData().
struct _pickle_xid_context ctx;
};
PyObject *
_PyPickle_LoadFromXIData(_PyXIData_t *xidata)
{
PyThreadState *tstate = _PyThreadState_GET();
struct _shared_pickle_data *shared =
(struct _shared_pickle_data *)xidata->data;
// We avoid copying the pickled data by wrapping it in a memoryview.
// The alternative is to get a bytes object using _PyBytes_FromXIData().
PyObject *pickled = PyMemoryView_FromMemory(
(char *)shared->pickled.bytes, shared->pickled.len, PyBUF_READ);
if (pickled == NULL) {
return NULL;
}
// Unpickle the object.
struct _unpickle_context ctx = {
.tstate = tstate,
.main = {
.filename = shared->ctx.mainfile.utf8,
},
};
PyObject *obj = _PyPickle_Loads(&ctx, pickled);
Py_DECREF(pickled);
_unpickle_context_clear(&ctx);
if (obj == NULL) {
PyObject *cause = _PyErr_GetRaisedException(tstate);
assert(cause != NULL);
_set_xid_lookup_failure(
tstate, NULL, "object could not be unpickled", cause);
Py_DECREF(cause);
}
return obj;
}
int
_PyPickle_GetXIData(PyThreadState *tstate, PyObject *obj, _PyXIData_t *xidata)
{
// Pickle the object.
struct _pickle_context ctx = {
.tstate = tstate,
};
PyObject *bytes = _PyPickle_Dumps(&ctx, obj);
if (bytes == NULL) {
PyObject *cause = _PyErr_GetRaisedException(tstate);
assert(cause != NULL);
_set_xid_lookup_failure(
tstate, NULL, "object could not be pickled", cause);
Py_DECREF(cause);
return -1;
}
// If we had an "unwrapper" mechnanism, we could call
// _PyObject_GetXIData() on the bytes object directly and add
// a simple unwrapper to call pickle.loads() on the bytes.
size_t size = sizeof(struct _shared_pickle_data);
struct _shared_pickle_data *shared =
(struct _shared_pickle_data *)_PyBytes_GetXIDataWrapped(
tstate, bytes, size, _PyPickle_LoadFromXIData, xidata);
Py_DECREF(bytes);
if (shared == NULL) {
return -1;
}
// If it mattered, we could skip getting __main__.__file__
// when "__main__" doesn't show up in the pickle bytes.
if (_set_pickle_xid_context(tstate, &shared->ctx) < 0) {
_xidata_clear(xidata);
return -1;
}
return 0;
}
/* marshal wrapper */
PyObject *
_PyMarshal_ReadObjectFromXIData(_PyXIData_t *xidata)
{
PyThreadState *tstate = _PyThreadState_GET();
_PyBytes_data_t *shared = (_PyBytes_data_t *)xidata->data;
PyObject *obj = PyMarshal_ReadObjectFromString(shared->bytes, shared->len);
if (obj == NULL) {
PyObject *cause = _PyErr_GetRaisedException(tstate);
assert(cause != NULL);
_set_xid_lookup_failure(
tstate, NULL, "object could not be unmarshalled", cause);
Py_DECREF(cause);
return NULL;
}
return obj;
}
int
_PyMarshal_GetXIData(PyThreadState *tstate, PyObject *obj, _PyXIData_t *xidata)
{
PyObject *bytes = PyMarshal_WriteObjectToString(obj, Py_MARSHAL_VERSION);
if (bytes == NULL) {
PyObject *cause = _PyErr_GetRaisedException(tstate);
assert(cause != NULL);
_set_xid_lookup_failure(
tstate, NULL, "object could not be marshalled", cause);
Py_DECREF(cause);
return -1;
}
size_t size = sizeof(_PyBytes_data_t);
_PyBytes_data_t *shared = _PyBytes_GetXIDataWrapped(
tstate, bytes, size, _PyMarshal_ReadObjectFromXIData, xidata);
Py_DECREF(bytes);
if (shared == NULL) {
return -1;
}
return 0;
}
/* script wrapper */
static int
verify_script(PyThreadState *tstate, PyCodeObject *co, int checked, int pure)
{
// Make sure it isn't a closure and (optionally) doesn't use globals.
PyObject *builtins = NULL;
if (pure) {
builtins = _PyEval_GetBuiltins(tstate);
assert(builtins != NULL);
}
if (checked) {
assert(_PyCode_VerifyStateless(tstate, co, NULL, NULL, builtins) == 0);
}
else if (_PyCode_VerifyStateless(tstate, co, NULL, NULL, builtins) < 0) {
return -1;
}
// Make sure it doesn't have args.
if (co->co_argcount > 0
|| co->co_posonlyargcount > 0
|| co->co_kwonlyargcount > 0
|| co->co_flags & (CO_VARARGS | CO_VARKEYWORDS))
{
_PyErr_SetString(tstate, PyExc_ValueError,
"code with args not supported");
return -1;
}
// Make sure it doesn't return anything.
if (!_PyCode_ReturnsOnlyNone(co)) {
_PyErr_SetString(tstate, PyExc_ValueError,
"code that returns a value is not a script");
return -1;
}
return 0;
}
static int
get_script_xidata(PyThreadState *tstate, PyObject *obj, int pure,
_PyXIData_t *xidata)
{
// Get the corresponding code object.
PyObject *code = NULL;
int checked = 0;
if (PyCode_Check(obj)) {
code = obj;
Py_INCREF(code);
}
else if (PyFunction_Check(obj)) {
code = PyFunction_GET_CODE(obj);
assert(code != NULL);
Py_INCREF(code);
if (pure) {
if (_PyFunction_VerifyStateless(tstate, obj) < 0) {
goto error;
}
checked = 1;
}
}
else {
const char *filename = "<script>";
int optimize = 0;
PyCompilerFlags cf = _PyCompilerFlags_INIT;
cf.cf_flags = PyCF_SOURCE_IS_UTF8;
PyObject *ref = NULL;
const char *script = _Py_SourceAsString(obj, "???", "???", &cf, &ref);
if (script == NULL) {
if (!_PyObject_SupportedAsScript(obj)) {
// We discard the raised exception.
_PyErr_Format(tstate, PyExc_TypeError,
"unsupported script %R", obj);
}
goto error;
}
#ifdef Py_GIL_DISABLED
// Don't immortalize code constants to avoid memory leaks.
((_PyThreadStateImpl *)tstate)->suppress_co_const_immortalization++;
#endif
code = Py_CompileStringExFlags(
script, filename, Py_file_input, &cf, optimize);
#ifdef Py_GIL_DISABLED
((_PyThreadStateImpl *)tstate)->suppress_co_const_immortalization--;
#endif
Py_XDECREF(ref);
if (code == NULL) {
goto error;
}
// Compiled text can't have args or any return statements,
// nor be a closure. It can use globals though.
if (!pure) {
// We don't need to check for globals either.
checked = 1;
}
}
// Make sure it's actually a script.
if (verify_script(tstate, (PyCodeObject *)code, checked, pure) < 0) {
goto error;
}
// Convert the code object.
int res = _PyCode_GetXIData(tstate, code, xidata);
Py_DECREF(code);
if (res < 0) {
return -1;
}
return 0;
error:
Py_XDECREF(code);
PyObject *cause = _PyErr_GetRaisedException(tstate);
assert(cause != NULL);
_set_xid_lookup_failure(
tstate, NULL, "object not a valid script", cause);
Py_DECREF(cause);
return -1;
}
int
_PyCode_GetScriptXIData(PyThreadState *tstate,
You can’t perform that action at this time.