forked from php/php-src
-
Notifications
You must be signed in to change notification settings - Fork 1
/
Copy pathzend_generators.c
1237 lines (1008 loc) · 37 KB
/
zend_generators.c
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
/*
+----------------------------------------------------------------------+
| Zend Engine |
+----------------------------------------------------------------------+
| Copyright (c) Zend Technologies Ltd. (http://www.zend.com) |
+----------------------------------------------------------------------+
| This source file is subject to version 2.00 of the Zend license, |
| that is bundled with this package in the file LICENSE, and is |
| available through the world-wide-web at the following url: |
| http://www.zend.com/license/2_00.txt. |
| If you did not receive a copy of the Zend license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| [email protected] so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Authors: Nikita Popov <[email protected]> |
| Bob Weinand <[email protected]> |
+----------------------------------------------------------------------+
*/
#include "zend.h"
#include "zend_API.h"
#include "zend_hash.h"
#include "zend_interfaces.h"
#include "zend_exceptions.h"
#include "zend_generators.h"
#include "zend_closures.h"
#include "zend_generators_arginfo.h"
#include "zend_observer.h"
#include "zend_vm_opcodes.h"
ZEND_API zend_class_entry *zend_ce_generator;
ZEND_API zend_class_entry *zend_ce_ClosedGeneratorException;
static zend_object_handlers zend_generator_handlers;
static zend_object *zend_generator_create(zend_class_entry *class_type);
ZEND_API void zend_generator_restore_call_stack(zend_generator *generator) /* {{{ */
{
zend_execute_data *call, *new_call, *prev_call = NULL;
call = generator->frozen_call_stack;
do {
new_call = zend_vm_stack_push_call_frame(
(ZEND_CALL_INFO(call) & ~ZEND_CALL_ALLOCATED),
call->func,
ZEND_CALL_NUM_ARGS(call),
Z_PTR(call->This));
memcpy(((zval*)new_call) + ZEND_CALL_FRAME_SLOT, ((zval*)call) + ZEND_CALL_FRAME_SLOT, ZEND_CALL_NUM_ARGS(call) * sizeof(zval));
new_call->extra_named_params = call->extra_named_params;
new_call->prev_execute_data = prev_call;
prev_call = new_call;
call = call->prev_execute_data;
} while (call);
generator->execute_data->call = prev_call;
efree(generator->frozen_call_stack);
generator->frozen_call_stack = NULL;
}
/* }}} */
ZEND_API zend_execute_data* zend_generator_freeze_call_stack(zend_execute_data *execute_data) /* {{{ */
{
size_t used_stack;
zend_execute_data *call, *new_call, *prev_call = NULL;
zval *stack;
/* calculate required stack size */
used_stack = 0;
call = EX(call);
do {
used_stack += ZEND_CALL_FRAME_SLOT + ZEND_CALL_NUM_ARGS(call);
call = call->prev_execute_data;
} while (call);
stack = emalloc(used_stack * sizeof(zval));
/* save stack, linking frames in reverse order */
call = EX(call);
do {
size_t frame_size = ZEND_CALL_FRAME_SLOT + ZEND_CALL_NUM_ARGS(call);
new_call = (zend_execute_data*)(stack + used_stack - frame_size);
memcpy(new_call, call, frame_size * sizeof(zval));
used_stack -= frame_size;
new_call->prev_execute_data = prev_call;
prev_call = new_call;
new_call = call->prev_execute_data;
zend_vm_stack_free_call_frame(call);
call = new_call;
} while (call);
execute_data->call = NULL;
ZEND_ASSERT(prev_call == (zend_execute_data*)stack);
return prev_call;
}
/* }}} */
static zend_execute_data* zend_generator_revert_call_stack(zend_execute_data *call)
{
zend_execute_data *prev = NULL;
do {
zend_execute_data *next = call->prev_execute_data;
call->prev_execute_data = prev;
prev = call;
call = next;
} while (call);
return prev;
}
static void zend_generator_cleanup_unfinished_execution(
zend_generator *generator, zend_execute_data *execute_data, uint32_t catch_op_num) /* {{{ */
{
zend_op_array *op_array = &execute_data->func->op_array;
if (execute_data->opline != op_array->opcodes) {
uint32_t op_num = execute_data->opline - op_array->opcodes;
if (UNEXPECTED(generator->frozen_call_stack)) {
/* Temporarily restore generator->execute_data if it has been NULLed out already. */
zend_execute_data *save_ex = generator->execute_data;
generator->execute_data = execute_data;
zend_generator_restore_call_stack(generator);
generator->execute_data = save_ex;
}
zend_cleanup_unfinished_execution(execute_data, op_num, catch_op_num);
}
}
/* }}} */
ZEND_API void zend_generator_close(zend_generator *generator, bool finished_execution) /* {{{ */
{
if (EXPECTED(generator->execute_data)) {
zend_execute_data *execute_data = generator->execute_data;
/* Null out execute_data early, to prevent double frees if GC runs while we're
* already cleaning up execute_data. */
generator->execute_data = NULL;
if (EX_CALL_INFO() & ZEND_CALL_HAS_SYMBOL_TABLE) {
zend_clean_and_cache_symbol_table(execute_data->symbol_table);
}
/* always free the CV's, in the symtable are only not-free'd IS_INDIRECT's */
zend_free_compiled_variables(execute_data);
if (EX_CALL_INFO() & ZEND_CALL_HAS_EXTRA_NAMED_PARAMS) {
zend_free_extra_named_params(execute_data->extra_named_params);
}
if (EX_CALL_INFO() & ZEND_CALL_RELEASE_THIS) {
OBJ_RELEASE(Z_OBJ(execute_data->This));
}
/* A fatal error / die occurred during the generator execution.
* Trying to clean up the stack may not be safe in this case. */
if (UNEXPECTED(CG(unclean_shutdown))) {
generator->execute_data = NULL;
return;
}
zend_vm_stack_free_extra_args(execute_data);
/* Some cleanups are only necessary if the generator was closed
* before it could finish execution (reach a return statement). */
if (UNEXPECTED(!finished_execution)) {
zend_generator_cleanup_unfinished_execution(generator, execute_data, 0);
}
efree(execute_data);
}
}
/* }}} */
static void zend_generator_remove_child(zend_generator_node *node, zend_generator *child)
{
ZEND_ASSERT(node->children >= 1);
if (node->children == 1) {
node->child.single = NULL;
} else {
HashTable *ht = node->child.ht;
zend_hash_index_del(ht, (zend_ulong) child);
if (node->children == 2) {
zend_generator *other_child;
ZEND_HASH_FOREACH_PTR(ht, other_child) {
node->child.single = other_child;
break;
} ZEND_HASH_FOREACH_END();
zend_hash_destroy(ht);
efree(ht);
}
}
node->children--;
}
static zend_always_inline zend_generator *clear_link_to_leaf(zend_generator *generator) {
ZEND_ASSERT(!generator->node.parent);
zend_generator *leaf = generator->node.ptr.leaf;
if (leaf) {
leaf->node.ptr.root = NULL;
generator->node.ptr.leaf = NULL;
return leaf;
}
return NULL;
}
static zend_always_inline void clear_link_to_root(zend_generator *generator) {
ZEND_ASSERT(generator->node.parent);
if (generator->node.ptr.root) {
generator->node.ptr.root->node.ptr.leaf = NULL;
generator->node.ptr.root = NULL;
}
}
/* In the context of zend_generator_dtor_storage during shutdown, check if
* the intermediate node 'generator' is running in a fiber */
static bool check_node_running_in_fiber(zend_generator *generator) {
ZEND_ASSERT(EG(flags) & EG_FLAGS_IN_SHUTDOWN);
ZEND_ASSERT(generator->execute_data);
if (generator->flags & ZEND_GENERATOR_IN_FIBER) {
return true;
}
if (generator->node.children == 0) {
return false;
}
if (generator->flags & ZEND_GENERATOR_DTOR_VISITED) {
return false;
}
generator->flags |= ZEND_GENERATOR_DTOR_VISITED;
if (generator->node.children == 1) {
if (check_node_running_in_fiber(generator->node.child.single)) {
goto in_fiber;
}
return false;
}
zend_generator *child;
ZEND_HASH_FOREACH_PTR(generator->node.child.ht, child) {
if (check_node_running_in_fiber(child)) {
goto in_fiber;
}
} ZEND_HASH_FOREACH_END();
return false;
in_fiber:
generator->flags |= ZEND_GENERATOR_IN_FIBER;
return true;
}
static void zend_generator_dtor_storage(zend_object *object) /* {{{ */
{
zend_generator *generator = (zend_generator*) object;
zend_generator *current_generator = zend_generator_get_current(generator);
zend_execute_data *ex = generator->execute_data;
uint32_t op_num, try_catch_offset;
int i;
/* If current_generator is running in a fiber, there are 2 cases to consider:
* - If generator is also marked with ZEND_GENERATOR_IN_FIBER, then the
* entire path from current_generator to generator is executing in a
* fiber. Do not dtor now: These will be dtor when terminating the fiber.
* - If generator is not marked with ZEND_GENERATOR_IN_FIBER, and has a
* child marked with ZEND_GENERATOR_IN_FIBER, then this an intermediate
* node of case 1. Otherwise generator is not executing in a fiber and we
* can dtor.
*/
if (current_generator->flags & ZEND_GENERATOR_IN_FIBER) {
if (check_node_running_in_fiber(generator)) {
/* Prevent finally blocks from yielding */
generator->flags |= ZEND_GENERATOR_FORCED_CLOSE;
return;
}
}
/* leave yield from mode to properly allow finally execution */
if (UNEXPECTED(Z_TYPE(generator->values) != IS_UNDEF)) {
zval_ptr_dtor(&generator->values);
ZVAL_UNDEF(&generator->values);
}
zend_generator *parent = generator->node.parent;
if (parent) {
zend_generator_remove_child(&parent->node, generator);
clear_link_to_root(generator);
generator->node.parent = NULL;
OBJ_RELEASE(&parent->std);
} else {
clear_link_to_leaf(generator);
}
if (EXPECTED(!ex) || EXPECTED(!(ex->func->op_array.fn_flags & ZEND_ACC_HAS_FINALLY_BLOCK))
|| CG(unclean_shutdown)) {
zend_generator_close(generator, 0);
return;
}
op_num = ex->opline - ex->func->op_array.opcodes;
try_catch_offset = -1;
/* Find the innermost try/catch that we are inside of. */
for (i = 0; i < ex->func->op_array.last_try_catch; i++) {
zend_try_catch_element *try_catch = &ex->func->op_array.try_catch_array[i];
if (op_num < try_catch->try_op) {
break;
}
if (op_num < try_catch->catch_op || op_num < try_catch->finally_end) {
try_catch_offset = i;
}
}
/* Walk try/catch/finally structures upwards, performing the necessary actions. */
while (try_catch_offset != (uint32_t) -1) {
zend_try_catch_element *try_catch = &ex->func->op_array.try_catch_array[try_catch_offset];
if (op_num < try_catch->finally_op) {
/* Go to finally block */
zval *fast_call =
ZEND_CALL_VAR(ex, ex->func->op_array.opcodes[try_catch->finally_end].op1.var);
zend_generator_cleanup_unfinished_execution(generator, ex, try_catch->finally_op);
zend_object *old_exception = EG(exception);
const zend_op *old_opline_before_exception = EG(opline_before_exception);
EG(exception) = NULL;
Z_OBJ_P(fast_call) = NULL;
Z_OPLINE_NUM_P(fast_call) = (uint32_t)-1;
/* -1 because zend_generator_resume() will increment it */
ex->opline = &ex->func->op_array.opcodes[try_catch->finally_op] - 1;
generator->flags |= ZEND_GENERATOR_FORCED_CLOSE;
zend_generator_resume(generator);
if (old_exception) {
EG(opline_before_exception) = old_opline_before_exception;
if (EG(exception)) {
zend_exception_set_previous(EG(exception), old_exception);
} else {
EG(exception) = old_exception;
}
}
/* TODO: If we hit another yield inside try/finally,
* should we also jump to the next finally block? */
break;
} else if (op_num < try_catch->finally_end) {
zval *fast_call =
ZEND_CALL_VAR(ex, ex->func->op_array.opcodes[try_catch->finally_end].op1.var);
/* Clean up incomplete return statement */
if (Z_OPLINE_NUM_P(fast_call) != (uint32_t) -1) {
zend_op *retval_op = &ex->func->op_array.opcodes[Z_OPLINE_NUM_P(fast_call)];
if (retval_op->op2_type & (IS_TMP_VAR | IS_VAR)) {
zval_ptr_dtor(ZEND_CALL_VAR(ex, retval_op->op2.var));
}
}
/* Clean up backed-up exception */
if (Z_OBJ_P(fast_call)) {
OBJ_RELEASE(Z_OBJ_P(fast_call));
}
}
try_catch_offset--;
}
zend_generator_close(generator, 0);
}
/* }}} */
static void zend_generator_free_storage(zend_object *object) /* {{{ */
{
zend_generator *generator = (zend_generator*) object;
zend_generator_close(generator, 0);
if (generator->func && (generator->func->common.fn_flags & ZEND_ACC_CLOSURE)) {
OBJ_RELEASE(ZEND_CLOSURE_OBJECT(generator->func));
}
/* we can't immediately free them in zend_generator_close() else yield from won't be able to fetch it */
zval_ptr_dtor(&generator->value);
zval_ptr_dtor(&generator->key);
if (EXPECTED(!Z_ISUNDEF(generator->retval))) {
zval_ptr_dtor(&generator->retval);
}
if (UNEXPECTED(generator->node.children > 1)) {
zend_hash_destroy(generator->node.child.ht);
efree(generator->node.child.ht);
}
zend_object_std_dtor(&generator->std);
}
/* }}} */
static HashTable *zend_generator_get_gc(zend_object *object, zval **table, int *n) /* {{{ */
{
zend_generator *generator = (zend_generator*)object;
zend_execute_data *execute_data = generator->execute_data;
zend_execute_data *call = NULL;
if (!execute_data) {
if (UNEXPECTED(generator->func->common.fn_flags & ZEND_ACC_CLOSURE)) {
zend_get_gc_buffer *gc_buffer = zend_get_gc_buffer_create();
zend_get_gc_buffer_add_zval(gc_buffer, &generator->value);
zend_get_gc_buffer_add_zval(gc_buffer, &generator->key);
zend_get_gc_buffer_add_zval(gc_buffer, &generator->retval);
zend_get_gc_buffer_add_obj(gc_buffer, ZEND_CLOSURE_OBJECT(generator->func));
zend_get_gc_buffer_use(gc_buffer, table, n);
} else {
/* If the non-closure generator has been closed, it can only hold on to three values: The value, key
* and retval. These three zvals are stored sequentially starting at &generator->value. */
*table = &generator->value;
*n = 3;
}
return NULL;
}
if (generator->flags & ZEND_GENERATOR_CURRENTLY_RUNNING) {
/* If the generator is currently running, we certainly won't be able to GC any values it
* holds on to. The execute_data state might be inconsistent during execution (e.g. because
* GC has been triggered in the middle of a variable reassignment), so we should not try
* to inspect it here. */
*table = NULL;
*n = 0;
return NULL;
}
zend_get_gc_buffer *gc_buffer = zend_get_gc_buffer_create();
zend_get_gc_buffer_add_zval(gc_buffer, &generator->value);
zend_get_gc_buffer_add_zval(gc_buffer, &generator->key);
zend_get_gc_buffer_add_zval(gc_buffer, &generator->retval);
zend_get_gc_buffer_add_zval(gc_buffer, &generator->values);
if (UNEXPECTED(generator->frozen_call_stack)) {
/* The frozen stack is linked in reverse order */
call = zend_generator_revert_call_stack(generator->frozen_call_stack);
}
zend_unfinished_execution_gc_ex(execute_data, call, gc_buffer, true);
if (UNEXPECTED(generator->frozen_call_stack)) {
zend_generator_revert_call_stack(call);
}
if (generator->node.parent) {
zend_get_gc_buffer_add_obj(gc_buffer, &generator->node.parent->std);
}
zend_get_gc_buffer_use(gc_buffer, table, n);
if (EX_CALL_INFO() & ZEND_CALL_HAS_SYMBOL_TABLE) {
return execute_data->symbol_table;
} else {
return NULL;
}
}
/* }}} */
static zend_object *zend_generator_create(zend_class_entry *class_type) /* {{{ */
{
zend_generator *generator = emalloc(sizeof(zend_generator));
memset(generator, 0, sizeof(zend_generator));
/* The key will be incremented on first use, so it'll start at 0 */
generator->largest_used_integer_key = -1;
ZVAL_UNDEF(&generator->retval);
ZVAL_UNDEF(&generator->values);
/* By default we have a tree of only one node */
generator->node.parent = NULL;
generator->node.children = 0;
generator->node.ptr.root = NULL;
zend_object_std_init(&generator->std, class_type);
return (zend_object*)generator;
}
/* }}} */
static ZEND_COLD zend_function *zend_generator_get_constructor(zend_object *object) /* {{{ */
{
zend_throw_error(NULL, "The \"Generator\" class is reserved for internal use and cannot be manually instantiated");
return NULL;
}
/* }}} */
ZEND_API zend_execute_data *zend_generator_check_placeholder_frame(zend_execute_data *ptr)
{
if (!ptr->func && Z_TYPE(ptr->This) == IS_OBJECT) {
if (Z_OBJCE(ptr->This) == zend_ce_generator) {
zend_generator *generator = (zend_generator *) Z_OBJ(ptr->This);
zend_execute_data *prev = ptr->prev_execute_data;
ZEND_ASSERT(generator->node.parent && "Placeholder only used with delegation");
while (generator->node.parent->node.parent) {
generator->execute_data->prev_execute_data = prev;
prev = generator->execute_data;
generator = generator->node.parent;
}
generator->execute_data->prev_execute_data = prev;
ptr = generator->execute_data;
}
}
return ptr;
}
static void zend_generator_throw_exception(zend_generator *generator, zval *exception)
{
zend_execute_data *original_execute_data = EG(current_execute_data);
/* Throw the exception in the context of the generator. Decrementing the opline
* to pretend the exception happened during the YIELD opcode. */
EG(current_execute_data) = generator->execute_data;
generator->execute_data->prev_execute_data = original_execute_data;
if (exception) {
zend_throw_exception_object(exception);
} else {
zend_rethrow_exception(EG(current_execute_data));
}
/* if we don't stop an array/iterator yield from, the exception will only reach the generator after the values were all iterated over */
if (UNEXPECTED(Z_TYPE(generator->values) != IS_UNDEF)) {
zval_ptr_dtor(&generator->values);
ZVAL_UNDEF(&generator->values);
}
EG(current_execute_data) = original_execute_data;
}
static void zend_generator_add_child(zend_generator *generator, zend_generator *child)
{
zend_generator_node *node = &generator->node;
if (node->children == 0) {
node->child.single = child;
} else {
if (node->children == 1) {
HashTable *ht = emalloc(sizeof(HashTable));
zend_hash_init(ht, 0, NULL, NULL, 0);
zend_hash_index_add_new_ptr(ht,
(zend_ulong) node->child.single, node->child.single);
node->child.ht = ht;
}
zend_hash_index_add_new_ptr(node->child.ht, (zend_ulong) child, child);
}
++node->children;
}
void zend_generator_yield_from(zend_generator *generator, zend_generator *from)
{
ZEND_ASSERT(!generator->node.parent && "Already has parent?");
zend_generator *leaf = clear_link_to_leaf(generator);
if (leaf && !from->node.parent && !from->node.ptr.leaf) {
from->node.ptr.leaf = leaf;
leaf->node.ptr.root = from;
}
generator->node.parent = from;
zend_generator_add_child(from, generator);
generator->flags |= ZEND_GENERATOR_DO_INIT;
}
ZEND_API zend_generator *zend_generator_update_root(zend_generator *generator)
{
zend_generator *root = generator->node.parent;
while (root->node.parent) {
root = root->node.parent;
}
clear_link_to_leaf(root);
root->node.ptr.leaf = generator;
generator->node.ptr.root = root;
return root;
}
static zend_generator *get_new_root(zend_generator *generator, zend_generator *root)
{
while (!root->execute_data && root->node.children == 1) {
root = root->node.child.single;
}
if (root->execute_data) {
return root;
}
/* We have reached a multi-child node haven't found the root yet. We don't know which
* child to follow, so perform the search from the other direction instead. */
while (generator->node.parent->execute_data) {
generator = generator->node.parent;
}
return generator;
}
ZEND_API zend_generator *zend_generator_update_current(zend_generator *generator)
{
zend_generator *old_root = generator->node.ptr.root;
ZEND_ASSERT(!old_root->execute_data && "Nothing to update?");
zend_generator *new_root = get_new_root(generator, old_root);
ZEND_ASSERT(old_root->node.ptr.leaf == generator);
generator->node.ptr.root = new_root;
new_root->node.ptr.leaf = generator;
old_root->node.ptr.leaf = NULL;
zend_generator *new_root_parent = new_root->node.parent;
ZEND_ASSERT(new_root_parent);
zend_generator_remove_child(&new_root_parent->node, new_root);
if (EXPECTED(EG(exception) == NULL) && EXPECTED((OBJ_FLAGS(&generator->std) & IS_OBJ_DESTRUCTOR_CALLED) == 0)) {
zend_op *yield_from = (zend_op *) new_root->execute_data->opline;
if (yield_from->opcode == ZEND_YIELD_FROM) {
if (Z_ISUNDEF(new_root_parent->retval)) {
/* Throw the exception in the context of the generator */
zend_execute_data *original_execute_data = EG(current_execute_data);
EG(current_execute_data) = new_root->execute_data;
if (new_root == generator) {
new_root->execute_data->prev_execute_data = original_execute_data;
} else {
new_root->execute_data->prev_execute_data = &generator->execute_fake;
generator->execute_fake.prev_execute_data = original_execute_data;
}
zend_throw_exception(zend_ce_ClosedGeneratorException, "Generator yielded from aborted, no return value available", 0);
EG(current_execute_data) = original_execute_data;
if (!(old_root->flags & ZEND_GENERATOR_CURRENTLY_RUNNING)) {
new_root->node.parent = NULL;
OBJ_RELEASE(&new_root_parent->std);
zend_generator_resume(generator);
return zend_generator_get_current(generator);
}
} else {
zval_ptr_dtor(&new_root->value);
ZVAL_COPY(&new_root->value, &new_root_parent->value);
ZVAL_COPY(ZEND_CALL_VAR(new_root->execute_data, yield_from->result.var), &new_root_parent->retval);
}
}
}
new_root->node.parent = NULL;
OBJ_RELEASE(&new_root_parent->std);
return new_root;
}
static zend_result zend_generator_get_next_delegated_value(zend_generator *generator) /* {{{ */
{
zval *value;
if (Z_TYPE(generator->values) == IS_ARRAY) {
HashTable *ht = Z_ARR(generator->values);
HashPosition pos = Z_FE_POS(generator->values);
if (HT_IS_PACKED(ht)) {
do {
if (UNEXPECTED(pos >= ht->nNumUsed)) {
/* Reached end of array */
goto failure;
}
value = &ht->arPacked[pos];
pos++;
} while (Z_ISUNDEF_P(value));
zval_ptr_dtor(&generator->value);
ZVAL_COPY(&generator->value, value);
zval_ptr_dtor(&generator->key);
ZVAL_LONG(&generator->key, pos - 1);
} else {
Bucket *p;
do {
if (UNEXPECTED(pos >= ht->nNumUsed)) {
/* Reached end of array */
goto failure;
}
p = &ht->arData[pos];
value = &p->val;
pos++;
} while (Z_ISUNDEF_P(value));
zval_ptr_dtor(&generator->value);
ZVAL_COPY(&generator->value, value);
zval_ptr_dtor(&generator->key);
if (p->key) {
ZVAL_STR_COPY(&generator->key, p->key);
} else {
ZVAL_LONG(&generator->key, p->h);
}
}
Z_FE_POS(generator->values) = pos;
} else {
zend_object_iterator *iter = (zend_object_iterator *) Z_OBJ(generator->values);
if (iter->index++ > 0) {
iter->funcs->move_forward(iter);
if (UNEXPECTED(EG(exception) != NULL)) {
goto failure;
}
}
if (iter->funcs->valid(iter) == FAILURE) {
/* reached end of iteration */
goto failure;
}
value = iter->funcs->get_current_data(iter);
if (UNEXPECTED(EG(exception) != NULL) || UNEXPECTED(!value)) {
goto failure;
}
zval_ptr_dtor(&generator->value);
ZVAL_COPY(&generator->value, value);
zval_ptr_dtor(&generator->key);
if (iter->funcs->get_current_key) {
iter->funcs->get_current_key(iter, &generator->key);
if (UNEXPECTED(EG(exception) != NULL)) {
ZVAL_UNDEF(&generator->key);
goto failure;
}
} else {
ZVAL_LONG(&generator->key, iter->index);
}
}
return SUCCESS;
failure:
zval_ptr_dtor(&generator->values);
ZVAL_UNDEF(&generator->values);
return FAILURE;
}
/* }}} */
ZEND_API void zend_generator_resume(zend_generator *orig_generator) /* {{{ */
{
zend_generator *generator = zend_generator_get_current(orig_generator);
/* The generator is already closed, thus can't resume */
if (UNEXPECTED(!generator->execute_data)) {
return;
}
try_again:
if (generator->flags & ZEND_GENERATOR_CURRENTLY_RUNNING) {
zend_throw_error(NULL, "Cannot resume an already running generator");
return;
}
if (UNEXPECTED((orig_generator->flags & ZEND_GENERATOR_DO_INIT) != 0 && !Z_ISUNDEF(generator->value))) {
/* We must not advance Generator if we yield from a Generator being currently run */
orig_generator->flags &= ~ZEND_GENERATOR_DO_INIT;
return;
}
if (EG(active_fiber)) {
orig_generator->flags |= ZEND_GENERATOR_IN_FIBER;
generator->flags |= ZEND_GENERATOR_IN_FIBER;
}
/* Drop the AT_FIRST_YIELD flag */
orig_generator->flags &= ~ZEND_GENERATOR_AT_FIRST_YIELD;
/* Backup executor globals */
zend_execute_data *original_execute_data = EG(current_execute_data);
uint32_t original_jit_trace_num = EG(jit_trace_num);
/* Set executor globals */
EG(current_execute_data) = generator->execute_data;
EG(jit_trace_num) = 0;
/* We want the backtrace to look as if the generator function was
* called from whatever method we are current running (e.g. next()).
* So we have to link generator call frame with caller call frame. */
if (generator == orig_generator) {
generator->execute_data->prev_execute_data = original_execute_data;
} else {
/* We need some execute_data placeholder in stacktrace to be replaced
* by the real stack trace when needed */
generator->execute_data->prev_execute_data = &orig_generator->execute_fake;
orig_generator->execute_fake.prev_execute_data = original_execute_data;
}
/* Ensure this is run after executor_data swap to have a proper stack trace */
if (UNEXPECTED(!Z_ISUNDEF(generator->values))) {
if (EXPECTED(zend_generator_get_next_delegated_value(generator) == SUCCESS)) {
/* Restore executor globals */
EG(current_execute_data) = original_execute_data;
EG(jit_trace_num) = original_jit_trace_num;
orig_generator->flags &= ~(ZEND_GENERATOR_DO_INIT | ZEND_GENERATOR_IN_FIBER);
generator->flags &= ~ZEND_GENERATOR_IN_FIBER;
return;
}
/* If there are no more delegated values, resume the generator
* after the "yield from" expression. */
}
if (UNEXPECTED(generator->frozen_call_stack)) {
/* Restore frozen call-stack */
zend_generator_restore_call_stack(generator);
}
/* Resume execution */
ZEND_ASSERT(generator->execute_data->opline->opcode == ZEND_GENERATOR_CREATE
|| generator->execute_data->opline->opcode == ZEND_YIELD
|| generator->execute_data->opline->opcode == ZEND_YIELD_FROM
/* opline points to EG(exception_op), which is a sequence of
* ZEND_HANDLE_EXCEPTION ops, so the following increment is safe */
|| generator->execute_data->opline->opcode == ZEND_HANDLE_EXCEPTION
/* opline points to the start of a finally block minus one op to
* account for the following increment */
|| (generator->flags & ZEND_GENERATOR_FORCED_CLOSE));
generator->execute_data->opline++;
generator->flags |= ZEND_GENERATOR_CURRENTLY_RUNNING;
if (!ZEND_OBSERVER_ENABLED) {
zend_execute_ex(generator->execute_data);
} else {
zend_observer_generator_resume(generator->execute_data);
zend_execute_ex(generator->execute_data);
if (generator->execute_data) {
/* On the final return, this will be called from ZEND_GENERATOR_RETURN */
zend_observer_fcall_end(generator->execute_data, &generator->value);
}
}
generator->flags &= ~(ZEND_GENERATOR_CURRENTLY_RUNNING | ZEND_GENERATOR_IN_FIBER);
generator->frozen_call_stack = NULL;
if (EXPECTED(generator->execute_data) &&
UNEXPECTED(generator->execute_data->call)) {
/* Frize call-stack */
generator->frozen_call_stack = zend_generator_freeze_call_stack(generator->execute_data);
}
/* Restore executor globals */
EG(current_execute_data) = original_execute_data;
EG(jit_trace_num) = original_jit_trace_num;
/* If an exception was thrown in the generator we have to internally
* rethrow it in the parent scope.
* In case we did yield from, the Exception must be rethrown into
* its calling frame (see above in if (check_yield_from). */
if (UNEXPECTED(EG(exception) != NULL)) {
if (generator == orig_generator) {
zend_generator_close(generator, 0);
if (!EG(current_execute_data)) {
zend_throw_exception_internal(NULL);
} else if (EG(current_execute_data)->func &&
ZEND_USER_CODE(EG(current_execute_data)->func->common.type)) {
zend_rethrow_exception(EG(current_execute_data));
}
} else {
generator = zend_generator_get_current(orig_generator);
zend_generator_throw_exception(generator, NULL);
orig_generator->flags &= ~ZEND_GENERATOR_DO_INIT;
goto try_again;
}
}
/* yield from was used, try another resume. */
if (UNEXPECTED((generator != orig_generator && !Z_ISUNDEF(generator->retval)) || (generator->execute_data && generator->execute_data->opline->opcode == ZEND_YIELD_FROM))) {
generator = zend_generator_get_current(orig_generator);
goto try_again;
}
orig_generator->flags &= ~(ZEND_GENERATOR_DO_INIT | ZEND_GENERATOR_IN_FIBER);
}
/* }}} */
static inline void zend_generator_ensure_initialized(zend_generator *generator) /* {{{ */
{
if (UNEXPECTED(Z_TYPE(generator->value) == IS_UNDEF) && EXPECTED(generator->execute_data) && EXPECTED(generator->node.parent == NULL)) {
zend_generator_resume(generator);
generator->flags |= ZEND_GENERATOR_AT_FIRST_YIELD;
}
}
/* }}} */
static inline void zend_generator_rewind(zend_generator *generator) /* {{{ */
{
zend_generator_ensure_initialized(generator);
if (!(generator->flags & ZEND_GENERATOR_AT_FIRST_YIELD)) {
zend_throw_exception(NULL, "Cannot rewind a generator that was already run", 0);
}
}
/* }}} */
/* {{{ Rewind the generator */
ZEND_METHOD(Generator, rewind)
{
zend_generator *generator;
ZEND_PARSE_PARAMETERS_NONE();
generator = (zend_generator *) Z_OBJ_P(ZEND_THIS);
zend_generator_rewind(generator);
}
/* }}} */
/* {{{ Check whether the generator is valid */
ZEND_METHOD(Generator, valid)
{
zend_generator *generator;
ZEND_PARSE_PARAMETERS_NONE();
generator = (zend_generator *) Z_OBJ_P(ZEND_THIS);
zend_generator_ensure_initialized(generator);
zend_generator_get_current(generator);
RETURN_BOOL(EXPECTED(generator->execute_data != NULL));
}
/* }}} */
/* {{{ Get the current value */
ZEND_METHOD(Generator, current)
{
zend_generator *generator, *root;
ZEND_PARSE_PARAMETERS_NONE();
generator = (zend_generator *) Z_OBJ_P(ZEND_THIS);
zend_generator_ensure_initialized(generator);
root = zend_generator_get_current(generator);
if (EXPECTED(generator->execute_data != NULL && Z_TYPE(root->value) != IS_UNDEF)) {
RETURN_COPY_DEREF(&root->value);
}
}
/* }}} */
/* {{{ Get the current key */
ZEND_METHOD(Generator, key)
{
zend_generator *generator, *root;
ZEND_PARSE_PARAMETERS_NONE();
generator = (zend_generator *) Z_OBJ_P(ZEND_THIS);
zend_generator_ensure_initialized(generator);
root = zend_generator_get_current(generator);
if (EXPECTED(generator->execute_data != NULL && Z_TYPE(root->key) != IS_UNDEF)) {
RETURN_COPY_DEREF(&root->key);
}
}
/* }}} */
/* {{{ Advances the generator */
ZEND_METHOD(Generator, next)
{
zend_generator *generator;
ZEND_PARSE_PARAMETERS_NONE();
generator = (zend_generator *) Z_OBJ_P(ZEND_THIS);
zend_generator_ensure_initialized(generator);
zend_generator_resume(generator);
}
/* }}} */
/* {{{ Sends a value to the generator */
ZEND_METHOD(Generator, send)
{
zval *value;
zend_generator *generator, *root;
ZEND_PARSE_PARAMETERS_START(1, 1)
Z_PARAM_ZVAL(value)
ZEND_PARSE_PARAMETERS_END();
generator = (zend_generator *) Z_OBJ_P(ZEND_THIS);
zend_generator_ensure_initialized(generator);
/* The generator is already closed, thus can't send anything */
if (UNEXPECTED(!generator->execute_data)) {
return;