1 /*
2 +----------------------------------------------------------------------+
3 | Zend Engine |
4 +----------------------------------------------------------------------+
5 | Copyright (c) Zend Technologies Ltd. (http://www.zend.com) |
6 +----------------------------------------------------------------------+
7 | This source file is subject to version 2.00 of the Zend license, |
8 | that is bundled with this package in the file LICENSE, and is |
9 | available through the world-wide-web at the following url: |
10 | http://www.zend.com/license/2_00.txt. |
11 | If you did not receive a copy of the Zend license and are unable to |
12 | obtain it through the world-wide-web, please send a note to |
13 | license@zend.com so we can mail you a copy immediately. |
14 +----------------------------------------------------------------------+
15 | Authors: Nikita Popov <nikic@php.net> |
16 | Bob Weinand <bobwei9@hotmail.com> |
17 +----------------------------------------------------------------------+
18 */
19
20 #include "zend.h"
21 #include "zend_API.h"
22 #include "zend_hash.h"
23 #include "zend_interfaces.h"
24 #include "zend_exceptions.h"
25 #include "zend_generators.h"
26 #include "zend_closures.h"
27 #include "zend_generators_arginfo.h"
28 #include "zend_observer.h"
29 #include "zend_vm_opcodes.h"
30
31 ZEND_API zend_class_entry *zend_ce_generator;
32 ZEND_API zend_class_entry *zend_ce_ClosedGeneratorException;
33 static zend_object_handlers zend_generator_handlers;
34
35 static zend_object *zend_generator_create(zend_class_entry *class_type);
36
zend_generator_restore_call_stack(zend_generator * generator)37 ZEND_API void zend_generator_restore_call_stack(zend_generator *generator) /* {{{ */
38 {
39 zend_execute_data *call, *new_call, *prev_call = NULL;
40
41 call = generator->frozen_call_stack;
42 do {
43 new_call = zend_vm_stack_push_call_frame(
44 (ZEND_CALL_INFO(call) & ~ZEND_CALL_ALLOCATED),
45 call->func,
46 ZEND_CALL_NUM_ARGS(call),
47 Z_PTR(call->This));
48 memcpy(((zval*)new_call) + ZEND_CALL_FRAME_SLOT, ((zval*)call) + ZEND_CALL_FRAME_SLOT, ZEND_CALL_NUM_ARGS(call) * sizeof(zval));
49 new_call->extra_named_params = call->extra_named_params;
50 new_call->prev_execute_data = prev_call;
51 prev_call = new_call;
52
53 call = call->prev_execute_data;
54 } while (call);
55 generator->execute_data->call = prev_call;
56 efree(generator->frozen_call_stack);
57 generator->frozen_call_stack = NULL;
58 }
59 /* }}} */
60
zend_generator_freeze_call_stack(zend_execute_data * execute_data)61 ZEND_API zend_execute_data* zend_generator_freeze_call_stack(zend_execute_data *execute_data) /* {{{ */
62 {
63 size_t used_stack;
64 zend_execute_data *call, *new_call, *prev_call = NULL;
65 zval *stack;
66
67 /* calculate required stack size */
68 used_stack = 0;
69 call = EX(call);
70 do {
71 used_stack += ZEND_CALL_FRAME_SLOT + ZEND_CALL_NUM_ARGS(call);
72 call = call->prev_execute_data;
73 } while (call);
74
75 stack = emalloc(used_stack * sizeof(zval));
76
77 /* save stack, linking frames in reverse order */
78 call = EX(call);
79 do {
80 size_t frame_size = ZEND_CALL_FRAME_SLOT + ZEND_CALL_NUM_ARGS(call);
81
82 new_call = (zend_execute_data*)(stack + used_stack - frame_size);
83 memcpy(new_call, call, frame_size * sizeof(zval));
84 used_stack -= frame_size;
85 new_call->prev_execute_data = prev_call;
86 prev_call = new_call;
87
88 new_call = call->prev_execute_data;
89 zend_vm_stack_free_call_frame(call);
90 call = new_call;
91 } while (call);
92
93 execute_data->call = NULL;
94 ZEND_ASSERT(prev_call == (zend_execute_data*)stack);
95
96 return prev_call;
97 }
98 /* }}} */
99
zend_generator_revert_call_stack(zend_execute_data * call)100 static zend_execute_data* zend_generator_revert_call_stack(zend_execute_data *call)
101 {
102 zend_execute_data *prev = NULL;
103
104 do {
105 zend_execute_data *next = call->prev_execute_data;
106 call->prev_execute_data = prev;
107 prev = call;
108 call = next;
109 } while (call);
110
111 return prev;
112 }
113
zend_generator_cleanup_unfinished_execution(zend_generator * generator,zend_execute_data * execute_data,uint32_t catch_op_num)114 static void zend_generator_cleanup_unfinished_execution(
115 zend_generator *generator, zend_execute_data *execute_data, uint32_t catch_op_num) /* {{{ */
116 {
117 zend_op_array *op_array = &execute_data->func->op_array;
118 if (execute_data->opline != op_array->opcodes) {
119 /* -1 required because we want the last run opcode, not the next to-be-run one. */
120 uint32_t op_num = execute_data->opline - op_array->opcodes - 1;
121
122 if (UNEXPECTED(generator->frozen_call_stack)) {
123 /* Temporarily restore generator->execute_data if it has been NULLed out already. */
124 zend_execute_data *save_ex = generator->execute_data;
125 generator->execute_data = execute_data;
126 zend_generator_restore_call_stack(generator);
127 generator->execute_data = save_ex;
128 }
129
130 zend_cleanup_unfinished_execution(execute_data, op_num, catch_op_num);
131 }
132 }
133 /* }}} */
134
zend_generator_close(zend_generator * generator,bool finished_execution)135 ZEND_API void zend_generator_close(zend_generator *generator, bool finished_execution) /* {{{ */
136 {
137 if (EXPECTED(generator->execute_data)) {
138 zend_execute_data *execute_data = generator->execute_data;
139 /* Null out execute_data early, to prevent double frees if GC runs while we're
140 * already cleaning up execute_data. */
141 generator->execute_data = NULL;
142
143 if (EX_CALL_INFO() & ZEND_CALL_HAS_SYMBOL_TABLE) {
144 zend_clean_and_cache_symbol_table(execute_data->symbol_table);
145 }
146 /* always free the CV's, in the symtable are only not-free'd IS_INDIRECT's */
147 zend_free_compiled_variables(execute_data);
148 if (EX_CALL_INFO() & ZEND_CALL_HAS_EXTRA_NAMED_PARAMS) {
149 zend_free_extra_named_params(execute_data->extra_named_params);
150 }
151
152 if (EX_CALL_INFO() & ZEND_CALL_RELEASE_THIS) {
153 OBJ_RELEASE(Z_OBJ(execute_data->This));
154 }
155
156 /* A fatal error / die occurred during the generator execution.
157 * Trying to clean up the stack may not be safe in this case. */
158 if (UNEXPECTED(CG(unclean_shutdown))) {
159 generator->execute_data = NULL;
160 return;
161 }
162
163 zend_vm_stack_free_extra_args(execute_data);
164
165 /* Some cleanups are only necessary if the generator was closed
166 * before it could finish execution (reach a return statement). */
167 if (UNEXPECTED(!finished_execution)) {
168 zend_generator_cleanup_unfinished_execution(generator, execute_data, 0);
169 }
170
171 /* Free closure object */
172 if (EX_CALL_INFO() & ZEND_CALL_CLOSURE) {
173 OBJ_RELEASE(ZEND_CLOSURE_OBJECT(EX(func)));
174 }
175
176 efree(execute_data);
177 }
178 }
179 /* }}} */
180
zend_generator_remove_child(zend_generator_node * node,zend_generator * child)181 static void zend_generator_remove_child(zend_generator_node *node, zend_generator *child)
182 {
183 ZEND_ASSERT(node->children >= 1);
184 if (node->children == 1) {
185 node->child.single = NULL;
186 } else {
187 HashTable *ht = node->child.ht;
188 zend_hash_index_del(ht, (zend_ulong) child);
189 if (node->children == 2) {
190 zend_generator *other_child;
191 ZEND_HASH_FOREACH_PTR(ht, other_child) {
192 node->child.single = other_child;
193 break;
194 } ZEND_HASH_FOREACH_END();
195 zend_hash_destroy(ht);
196 efree(ht);
197 }
198 }
199 node->children--;
200 }
201
clear_link_to_leaf(zend_generator * generator)202 static zend_always_inline zend_generator *clear_link_to_leaf(zend_generator *generator) {
203 ZEND_ASSERT(!generator->node.parent);
204 zend_generator *leaf = generator->node.ptr.leaf;
205 if (leaf) {
206 leaf->node.ptr.root = NULL;
207 generator->node.ptr.leaf = NULL;
208 return leaf;
209 }
210 return NULL;
211 }
212
clear_link_to_root(zend_generator * generator)213 static zend_always_inline void clear_link_to_root(zend_generator *generator) {
214 ZEND_ASSERT(generator->node.parent);
215 if (generator->node.ptr.root) {
216 generator->node.ptr.root->node.ptr.leaf = NULL;
217 generator->node.ptr.root = NULL;
218 }
219 }
220
221 /* In the context of zend_generator_dtor_storage during shutdown, check if
222 * the intermediate node 'generator' is running in a fiber */
check_node_running_in_fiber(zend_generator * generator)223 static inline bool check_node_running_in_fiber(zend_generator *generator) {
224 ZEND_ASSERT(EG(flags) & EG_FLAGS_IN_SHUTDOWN);
225 ZEND_ASSERT(generator->execute_data);
226
227 if (generator->flags & ZEND_GENERATOR_IN_FIBER) {
228 return true;
229 }
230
231 if (generator->node.children == 0) {
232 return false;
233 }
234
235 if (generator->flags & ZEND_GENERATOR_DTOR_VISITED) {
236 return false;
237 }
238 generator->flags |= ZEND_GENERATOR_DTOR_VISITED;
239
240 if (generator->node.children == 1) {
241 if (check_node_running_in_fiber(generator->node.child.single)) {
242 goto in_fiber;
243 }
244 return false;
245 }
246
247 zend_generator *child;
248 ZEND_HASH_FOREACH_PTR(generator->node.child.ht, child) {
249 if (check_node_running_in_fiber(child)) {
250 goto in_fiber;
251 }
252 } ZEND_HASH_FOREACH_END();
253 return false;
254
255 in_fiber:
256 generator->flags |= ZEND_GENERATOR_IN_FIBER;
257 return true;
258 }
259
zend_generator_dtor_storage(zend_object * object)260 static void zend_generator_dtor_storage(zend_object *object) /* {{{ */
261 {
262 zend_generator *generator = (zend_generator*) object;
263 zend_generator *current_generator = zend_generator_get_current(generator);
264 zend_execute_data *ex = generator->execute_data;
265 uint32_t op_num, try_catch_offset;
266 int i;
267
268 /* If current_generator is running in a fiber, there are 2 cases to consider:
269 * - If generator is also marked with ZEND_GENERATOR_IN_FIBER, then the
270 * entire path from current_generator to generator is executing in a
271 * fiber. Do not dtor now: These will be dtor when terminating the fiber.
272 * - If generator is not marked with ZEND_GENERATOR_IN_FIBER, and has a
273 * child marked with ZEND_GENERATOR_IN_FIBER, then this an intermediate
274 * node of case 1. Otherwise generator is not executing in a fiber and we
275 * can dtor.
276 */
277 if (current_generator->flags & ZEND_GENERATOR_IN_FIBER) {
278 if (check_node_running_in_fiber(generator)) {
279 /* Prevent finally blocks from yielding */
280 generator->flags |= ZEND_GENERATOR_FORCED_CLOSE;
281 return;
282 }
283 }
284
285 /* leave yield from mode to properly allow finally execution */
286 if (UNEXPECTED(Z_TYPE(generator->values) != IS_UNDEF)) {
287 zval_ptr_dtor(&generator->values);
288 ZVAL_UNDEF(&generator->values);
289 }
290
291 zend_generator *parent = generator->node.parent;
292 if (parent) {
293 zend_generator_remove_child(&parent->node, generator);
294 clear_link_to_root(generator);
295 generator->node.parent = NULL;
296 OBJ_RELEASE(&parent->std);
297 } else {
298 clear_link_to_leaf(generator);
299 }
300
301 if (EXPECTED(!ex) || EXPECTED(!(ex->func->op_array.fn_flags & ZEND_ACC_HAS_FINALLY_BLOCK))
302 || CG(unclean_shutdown)) {
303 zend_generator_close(generator, 0);
304 return;
305 }
306
307 /* -1 required because we want the last run opcode, not the
308 * next to-be-run one. */
309 op_num = ex->opline - ex->func->op_array.opcodes - 1;
310 try_catch_offset = -1;
311
312 /* Find the innermost try/catch that we are inside of. */
313 for (i = 0; i < ex->func->op_array.last_try_catch; i++) {
314 zend_try_catch_element *try_catch = &ex->func->op_array.try_catch_array[i];
315 if (op_num < try_catch->try_op) {
316 break;
317 }
318 if (op_num < try_catch->catch_op || op_num < try_catch->finally_end) {
319 try_catch_offset = i;
320 }
321 }
322
323 /* Walk try/catch/finally structures upwards, performing the necessary actions. */
324 while (try_catch_offset != (uint32_t) -1) {
325 zend_try_catch_element *try_catch = &ex->func->op_array.try_catch_array[try_catch_offset];
326
327 if (op_num < try_catch->finally_op) {
328 /* Go to finally block */
329 zval *fast_call =
330 ZEND_CALL_VAR(ex, ex->func->op_array.opcodes[try_catch->finally_end].op1.var);
331
332 zend_generator_cleanup_unfinished_execution(generator, ex, try_catch->finally_op);
333 zend_object *old_exception = EG(exception);
334 const zend_op *old_opline_before_exception = EG(opline_before_exception);
335 EG(exception) = NULL;
336 Z_OBJ_P(fast_call) = NULL;
337 Z_OPLINE_NUM_P(fast_call) = (uint32_t)-1;
338
339 ex->opline = &ex->func->op_array.opcodes[try_catch->finally_op];
340 generator->flags |= ZEND_GENERATOR_FORCED_CLOSE;
341 zend_generator_resume(generator);
342
343 if (old_exception) {
344 EG(opline_before_exception) = old_opline_before_exception;
345 if (EG(exception)) {
346 zend_exception_set_previous(EG(exception), old_exception);
347 } else {
348 EG(exception) = old_exception;
349 }
350 }
351
352 /* TODO: If we hit another yield inside try/finally,
353 * should we also jump to the next finally block? */
354 break;
355 } else if (op_num < try_catch->finally_end) {
356 zval *fast_call =
357 ZEND_CALL_VAR(ex, ex->func->op_array.opcodes[try_catch->finally_end].op1.var);
358 /* Clean up incomplete return statement */
359 if (Z_OPLINE_NUM_P(fast_call) != (uint32_t) -1) {
360 zend_op *retval_op = &ex->func->op_array.opcodes[Z_OPLINE_NUM_P(fast_call)];
361 if (retval_op->op2_type & (IS_TMP_VAR | IS_VAR)) {
362 zval_ptr_dtor(ZEND_CALL_VAR(ex, retval_op->op2.var));
363 }
364 }
365 /* Clean up backed-up exception */
366 if (Z_OBJ_P(fast_call)) {
367 OBJ_RELEASE(Z_OBJ_P(fast_call));
368 }
369 }
370
371 try_catch_offset--;
372 }
373
374 zend_generator_close(generator, 0);
375 }
376 /* }}} */
377
zend_generator_free_storage(zend_object * object)378 static void zend_generator_free_storage(zend_object *object) /* {{{ */
379 {
380 zend_generator *generator = (zend_generator*) object;
381
382 zend_generator_close(generator, 0);
383
384 /* we can't immediately free them in zend_generator_close() else yield from won't be able to fetch it */
385 zval_ptr_dtor(&generator->value);
386 zval_ptr_dtor(&generator->key);
387
388 if (EXPECTED(!Z_ISUNDEF(generator->retval))) {
389 zval_ptr_dtor(&generator->retval);
390 }
391
392 if (UNEXPECTED(generator->node.children > 1)) {
393 zend_hash_destroy(generator->node.child.ht);
394 efree(generator->node.child.ht);
395 }
396
397 zend_object_std_dtor(&generator->std);
398 }
399 /* }}} */
400
zend_generator_frame_gc(zend_get_gc_buffer * gc_buffer,zend_generator * generator)401 HashTable *zend_generator_frame_gc(zend_get_gc_buffer *gc_buffer, zend_generator *generator)
402 {
403 zend_execute_data *execute_data = generator->execute_data;
404 zend_execute_data *call = NULL;
405
406 zend_get_gc_buffer_add_zval(gc_buffer, &generator->value);
407 zend_get_gc_buffer_add_zval(gc_buffer, &generator->key);
408 zend_get_gc_buffer_add_zval(gc_buffer, &generator->retval);
409 zend_get_gc_buffer_add_zval(gc_buffer, &generator->values);
410
411 if (UNEXPECTED(generator->frozen_call_stack)) {
412 /* The frozen stack is linked in reverse order */
413 call = zend_generator_revert_call_stack(generator->frozen_call_stack);
414 }
415
416 HashTable *ht = zend_unfinished_execution_gc_ex(execute_data, call, gc_buffer, true);
417
418 if (UNEXPECTED(generator->frozen_call_stack)) {
419 zend_generator_revert_call_stack(call);
420 }
421
422 if (generator->node.parent) {
423 zend_get_gc_buffer_add_obj(gc_buffer, &generator->node.parent->std);
424 }
425
426 return ht;
427 }
428
zend_generator_get_gc(zend_object * object,zval ** table,int * n)429 static HashTable *zend_generator_get_gc(zend_object *object, zval **table, int *n) /* {{{ */
430 {
431 zend_generator *generator = (zend_generator*)object;
432 zend_execute_data *execute_data = generator->execute_data;
433
434 if (!execute_data) {
435 /* If the generator has been closed, it can only hold on to three values: The value, key
436 * and retval. These three zvals are stored sequentially starting at &generator->value. */
437 *table = &generator->value;
438 *n = 3;
439 return NULL;
440 }
441
442 if (generator->flags & ZEND_GENERATOR_CURRENTLY_RUNNING) {
443 /* If the generator is currently running, we certainly won't be able to GC any values it
444 * holds on to. The execute_data state might be inconsistent during execution (e.g. because
445 * GC has been triggered in the middle of a variable reassignment), so we should not try
446 * to inspect it here. */
447 *table = NULL;
448 *n = 0;
449 return NULL;
450 }
451
452 zend_get_gc_buffer *gc_buffer = zend_get_gc_buffer_create();
453 HashTable *ht = zend_generator_frame_gc(gc_buffer, generator);
454 zend_get_gc_buffer_use(gc_buffer, table, n);
455
456 return ht;
457 }
458 /* }}} */
459
zend_generator_create(zend_class_entry * class_type)460 static zend_object *zend_generator_create(zend_class_entry *class_type) /* {{{ */
461 {
462 zend_generator *generator = emalloc(sizeof(zend_generator));
463 memset(generator, 0, sizeof(zend_generator));
464
465 /* The key will be incremented on first use, so it'll start at 0 */
466 generator->largest_used_integer_key = -1;
467
468 ZVAL_UNDEF(&generator->retval);
469 ZVAL_UNDEF(&generator->values);
470
471 /* By default we have a tree of only one node */
472 generator->node.parent = NULL;
473 generator->node.children = 0;
474 generator->node.ptr.root = NULL;
475
476 zend_object_std_init(&generator->std, class_type);
477 return (zend_object*)generator;
478 }
479 /* }}} */
480
zend_generator_get_constructor(zend_object * object)481 static ZEND_COLD zend_function *zend_generator_get_constructor(zend_object *object) /* {{{ */
482 {
483 zend_throw_error(NULL, "The \"Generator\" class is reserved for internal use and cannot be manually instantiated");
484
485 return NULL;
486 }
487 /* }}} */
488
zend_generator_check_placeholder_frame(zend_execute_data * ptr)489 ZEND_API zend_execute_data *zend_generator_check_placeholder_frame(zend_execute_data *ptr)
490 {
491 if (!ptr->func && Z_TYPE(ptr->This) == IS_OBJECT) {
492 if (Z_OBJCE(ptr->This) == zend_ce_generator) {
493 zend_generator *generator = (zend_generator *) Z_OBJ(ptr->This);
494 zend_execute_data *prev = ptr->prev_execute_data;
495 ZEND_ASSERT(generator->node.parent && "Placeholder only used with delegation");
496 while (generator->node.parent->node.parent) {
497 generator->execute_data->prev_execute_data = prev;
498 prev = generator->execute_data;
499 generator = generator->node.parent;
500 }
501 generator->execute_data->prev_execute_data = prev;
502 ptr = generator->execute_data;
503 }
504 }
505 return ptr;
506 }
507
zend_generator_throw_exception(zend_generator * generator,zval * exception)508 static void zend_generator_throw_exception(zend_generator *generator, zval *exception)
509 {
510 zend_execute_data *original_execute_data = EG(current_execute_data);
511
512 /* Throw the exception in the context of the generator. Decrementing the opline
513 * to pretend the exception happened during the YIELD opcode. */
514 EG(current_execute_data) = generator->execute_data;
515 generator->execute_data->opline--;
516 ZEND_ASSERT(generator->execute_data->opline->opcode == ZEND_YIELD
517 || generator->execute_data->opline->opcode == ZEND_YIELD_FROM);
518 generator->execute_data->prev_execute_data = original_execute_data;
519
520 if (exception) {
521 zend_throw_exception_object(exception);
522 } else {
523 zend_rethrow_exception(EG(current_execute_data));
524 }
525
526 generator->execute_data->opline++;
527
528 /* if we don't stop an array/iterator yield from, the exception will only reach the generator after the values were all iterated over */
529 if (UNEXPECTED(Z_TYPE(generator->values) != IS_UNDEF)) {
530 zval_ptr_dtor(&generator->values);
531 ZVAL_UNDEF(&generator->values);
532 }
533
534 EG(current_execute_data) = original_execute_data;
535 }
536
zend_generator_add_child(zend_generator * generator,zend_generator * child)537 static void zend_generator_add_child(zend_generator *generator, zend_generator *child)
538 {
539 zend_generator_node *node = &generator->node;
540
541 if (node->children == 0) {
542 node->child.single = child;
543 } else {
544 if (node->children == 1) {
545 HashTable *ht = emalloc(sizeof(HashTable));
546 zend_hash_init(ht, 0, NULL, NULL, 0);
547 zend_hash_index_add_new_ptr(ht,
548 (zend_ulong) node->child.single, node->child.single);
549 node->child.ht = ht;
550 }
551
552 zend_hash_index_add_new_ptr(node->child.ht, (zend_ulong) child, child);
553 }
554
555 ++node->children;
556 }
557
zend_generator_yield_from(zend_generator * generator,zend_generator * from)558 void zend_generator_yield_from(zend_generator *generator, zend_generator *from)
559 {
560 ZEND_ASSERT(!generator->node.parent && "Already has parent?");
561 zend_generator *leaf = clear_link_to_leaf(generator);
562 if (leaf && !from->node.parent && !from->node.ptr.leaf) {
563 from->node.ptr.leaf = leaf;
564 leaf->node.ptr.root = from;
565 }
566 generator->node.parent = from;
567 zend_generator_add_child(from, generator);
568 generator->flags |= ZEND_GENERATOR_DO_INIT;
569 }
570
zend_generator_update_root(zend_generator * generator)571 ZEND_API zend_generator *zend_generator_update_root(zend_generator *generator)
572 {
573 zend_generator *root = generator->node.parent;
574 while (root->node.parent) {
575 root = root->node.parent;
576 }
577
578 clear_link_to_leaf(root);
579 root->node.ptr.leaf = generator;
580 generator->node.ptr.root = root;
581 return root;
582 }
583
get_new_root(zend_generator * generator,zend_generator * root)584 static zend_generator *get_new_root(zend_generator *generator, zend_generator *root)
585 {
586 while (!root->execute_data && root->node.children == 1) {
587 root = root->node.child.single;
588 }
589
590 if (root->execute_data) {
591 return root;
592 }
593
594 /* We have reached a multi-child node haven't found the root yet. We don't know which
595 * child to follow, so perform the search from the other direction instead. */
596 while (generator->node.parent->execute_data) {
597 generator = generator->node.parent;
598 }
599
600 return generator;
601 }
602
zend_generator_update_current(zend_generator * generator)603 ZEND_API zend_generator *zend_generator_update_current(zend_generator *generator)
604 {
605 zend_generator *old_root = generator->node.ptr.root;
606 ZEND_ASSERT(!old_root->execute_data && "Nothing to update?");
607
608 zend_generator *new_root = get_new_root(generator, old_root);
609
610 ZEND_ASSERT(old_root->node.ptr.leaf == generator);
611 generator->node.ptr.root = new_root;
612 new_root->node.ptr.leaf = generator;
613 old_root->node.ptr.leaf = NULL;
614
615 zend_generator *new_root_parent = new_root->node.parent;
616 ZEND_ASSERT(new_root_parent);
617 zend_generator_remove_child(&new_root_parent->node, new_root);
618
619 if (EXPECTED(EG(exception) == NULL) && EXPECTED((OBJ_FLAGS(&generator->std) & IS_OBJ_DESTRUCTOR_CALLED) == 0)) {
620 zend_op *yield_from = (zend_op *) new_root->execute_data->opline - 1;
621
622 if (yield_from->opcode == ZEND_YIELD_FROM) {
623 if (Z_ISUNDEF(new_root_parent->retval)) {
624 /* Throw the exception in the context of the generator */
625 zend_execute_data *original_execute_data = EG(current_execute_data);
626 EG(current_execute_data) = new_root->execute_data;
627
628 if (new_root == generator) {
629 new_root->execute_data->prev_execute_data = original_execute_data;
630 } else {
631 new_root->execute_data->prev_execute_data = &generator->execute_fake;
632 generator->execute_fake.prev_execute_data = original_execute_data;
633 }
634
635 /* ZEND_YIELD(_FROM) already advance, so decrement opline to throw from correct place */
636 new_root->execute_data->opline--;
637 zend_throw_exception(zend_ce_ClosedGeneratorException, "Generator yielded from aborted, no return value available", 0);
638
639 EG(current_execute_data) = original_execute_data;
640
641 if (!((old_root ? old_root : generator)->flags & ZEND_GENERATOR_CURRENTLY_RUNNING)) {
642 new_root->node.parent = NULL;
643 OBJ_RELEASE(&new_root_parent->std);
644 zend_generator_resume(generator);
645 return zend_generator_get_current(generator);
646 }
647 } else {
648 zval_ptr_dtor(&new_root->value);
649 ZVAL_COPY(&new_root->value, &new_root_parent->value);
650 ZVAL_COPY(ZEND_CALL_VAR(new_root->execute_data, yield_from->result.var), &new_root_parent->retval);
651 }
652 }
653 }
654
655 new_root->node.parent = NULL;
656 OBJ_RELEASE(&new_root_parent->std);
657
658 return new_root;
659 }
660
zend_generator_get_next_delegated_value(zend_generator * generator)661 static zend_result zend_generator_get_next_delegated_value(zend_generator *generator) /* {{{ */
662 {
663 zval *value;
664 if (Z_TYPE(generator->values) == IS_ARRAY) {
665 HashTable *ht = Z_ARR(generator->values);
666 HashPosition pos = Z_FE_POS(generator->values);
667
668 if (HT_IS_PACKED(ht)) {
669 do {
670 if (UNEXPECTED(pos >= ht->nNumUsed)) {
671 /* Reached end of array */
672 goto failure;
673 }
674
675 value = &ht->arPacked[pos];
676 pos++;
677 } while (Z_ISUNDEF_P(value));
678
679 zval_ptr_dtor(&generator->value);
680 ZVAL_COPY(&generator->value, value);
681
682 zval_ptr_dtor(&generator->key);
683 ZVAL_LONG(&generator->key, pos - 1);
684 } else {
685 Bucket *p;
686
687 do {
688 if (UNEXPECTED(pos >= ht->nNumUsed)) {
689 /* Reached end of array */
690 goto failure;
691 }
692
693 p = &ht->arData[pos];
694 value = &p->val;
695 pos++;
696 } while (Z_ISUNDEF_P(value));
697
698 zval_ptr_dtor(&generator->value);
699 ZVAL_COPY(&generator->value, value);
700
701 zval_ptr_dtor(&generator->key);
702 if (p->key) {
703 ZVAL_STR_COPY(&generator->key, p->key);
704 } else {
705 ZVAL_LONG(&generator->key, p->h);
706 }
707 }
708 Z_FE_POS(generator->values) = pos;
709 } else {
710 zend_object_iterator *iter = (zend_object_iterator *) Z_OBJ(generator->values);
711
712 if (iter->index++ > 0) {
713 iter->funcs->move_forward(iter);
714 if (UNEXPECTED(EG(exception) != NULL)) {
715 goto failure;
716 }
717 }
718
719 if (iter->funcs->valid(iter) == FAILURE) {
720 /* reached end of iteration */
721 goto failure;
722 }
723
724 value = iter->funcs->get_current_data(iter);
725 if (UNEXPECTED(EG(exception) != NULL) || UNEXPECTED(!value)) {
726 goto failure;
727 }
728
729 zval_ptr_dtor(&generator->value);
730 ZVAL_COPY(&generator->value, value);
731
732 zval_ptr_dtor(&generator->key);
733 if (iter->funcs->get_current_key) {
734 iter->funcs->get_current_key(iter, &generator->key);
735 if (UNEXPECTED(EG(exception) != NULL)) {
736 ZVAL_UNDEF(&generator->key);
737 goto failure;
738 }
739 } else {
740 ZVAL_LONG(&generator->key, iter->index);
741 }
742 }
743
744 return SUCCESS;
745
746 failure:
747 zval_ptr_dtor(&generator->values);
748 ZVAL_UNDEF(&generator->values);
749
750 return FAILURE;
751 }
752 /* }}} */
753
zend_generator_resume(zend_generator * orig_generator)754 ZEND_API void zend_generator_resume(zend_generator *orig_generator) /* {{{ */
755 {
756 zend_generator *generator = zend_generator_get_current(orig_generator);
757
758 /* The generator is already closed, thus can't resume */
759 if (UNEXPECTED(!generator->execute_data)) {
760 return;
761 }
762
763 try_again:
764 if (generator->flags & ZEND_GENERATOR_CURRENTLY_RUNNING) {
765 zend_throw_error(NULL, "Cannot resume an already running generator");
766 return;
767 }
768
769 if (UNEXPECTED((orig_generator->flags & ZEND_GENERATOR_DO_INIT) != 0 && !Z_ISUNDEF(generator->value))) {
770 /* We must not advance Generator if we yield from a Generator being currently run */
771 orig_generator->flags &= ~ZEND_GENERATOR_DO_INIT;
772 return;
773 }
774
775 if (EG(active_fiber)) {
776 orig_generator->flags |= ZEND_GENERATOR_IN_FIBER;
777 generator->flags |= ZEND_GENERATOR_IN_FIBER;
778 }
779
780 /* Drop the AT_FIRST_YIELD flag */
781 orig_generator->flags &= ~ZEND_GENERATOR_AT_FIRST_YIELD;
782
783 /* Backup executor globals */
784 zend_execute_data *original_execute_data = EG(current_execute_data);
785 uint32_t original_jit_trace_num = EG(jit_trace_num);
786
787 /* Set executor globals */
788 EG(current_execute_data) = generator->execute_data;
789 EG(jit_trace_num) = 0;
790
791 /* We want the backtrace to look as if the generator function was
792 * called from whatever method we are current running (e.g. next()).
793 * So we have to link generator call frame with caller call frame. */
794 if (generator == orig_generator) {
795 generator->execute_data->prev_execute_data = original_execute_data;
796 } else {
797 /* We need some execute_data placeholder in stacktrace to be replaced
798 * by the real stack trace when needed */
799 generator->execute_data->prev_execute_data = &orig_generator->execute_fake;
800 orig_generator->execute_fake.prev_execute_data = original_execute_data;
801 }
802
803 /* Ensure this is run after executor_data swap to have a proper stack trace */
804 if (UNEXPECTED(!Z_ISUNDEF(generator->values))) {
805 if (EXPECTED(zend_generator_get_next_delegated_value(generator) == SUCCESS)) {
806 /* Restore executor globals */
807 EG(current_execute_data) = original_execute_data;
808 EG(jit_trace_num) = original_jit_trace_num;
809
810 orig_generator->flags &= ~(ZEND_GENERATOR_DO_INIT | ZEND_GENERATOR_IN_FIBER);
811 generator->flags &= ~ZEND_GENERATOR_IN_FIBER;
812 return;
813 }
814 if (UNEXPECTED(EG(exception))) {
815 /* Decrementing opline_before_exception to pretend the exception
816 * happened during the YIELD_FROM opcode. */
817 if (generator->execute_data) {
818 ZEND_ASSERT(generator->execute_data->opline == EG(exception_op));
819 ZEND_ASSERT((EG(opline_before_exception)-1)->opcode == ZEND_YIELD_FROM);
820 EG(opline_before_exception)--;
821 }
822 }
823 /* If there are no more delegated values, resume the generator
824 * after the "yield from" expression. */
825 }
826
827 if (UNEXPECTED(generator->frozen_call_stack)) {
828 /* Restore frozen call-stack */
829 zend_generator_restore_call_stack(generator);
830 }
831
832 /* Resume execution */
833 generator->flags |= ZEND_GENERATOR_CURRENTLY_RUNNING;
834 if (!ZEND_OBSERVER_ENABLED) {
835 zend_execute_ex(generator->execute_data);
836 } else {
837 zend_observer_generator_resume(generator->execute_data);
838 zend_execute_ex(generator->execute_data);
839 if (generator->execute_data) {
840 /* On the final return, this will be called from ZEND_GENERATOR_RETURN */
841 zend_observer_fcall_end(generator->execute_data, &generator->value);
842 }
843 }
844 generator->flags &= ~(ZEND_GENERATOR_CURRENTLY_RUNNING | ZEND_GENERATOR_IN_FIBER);
845
846 generator->frozen_call_stack = NULL;
847 if (EXPECTED(generator->execute_data) &&
848 UNEXPECTED(generator->execute_data->call)) {
849 /* Frize call-stack */
850 generator->frozen_call_stack = zend_generator_freeze_call_stack(generator->execute_data);
851 }
852
853 /* Restore executor globals */
854 EG(current_execute_data) = original_execute_data;
855 EG(jit_trace_num) = original_jit_trace_num;
856
857 /* If an exception was thrown in the generator we have to internally
858 * rethrow it in the parent scope.
859 * In case we did yield from, the Exception must be rethrown into
860 * its calling frame (see above in if (check_yield_from). */
861 if (UNEXPECTED(EG(exception) != NULL)) {
862 if (generator == orig_generator) {
863 zend_generator_close(generator, 0);
864 if (!EG(current_execute_data)) {
865 zend_throw_exception_internal(NULL);
866 } else if (EG(current_execute_data)->func &&
867 ZEND_USER_CODE(EG(current_execute_data)->func->common.type)) {
868 zend_rethrow_exception(EG(current_execute_data));
869 }
870 } else {
871 generator = zend_generator_get_current(orig_generator);
872 zend_generator_throw_exception(generator, NULL);
873 orig_generator->flags &= ~ZEND_GENERATOR_DO_INIT;
874 goto try_again;
875 }
876 }
877
878 /* yield from was used, try another resume. */
879 if (UNEXPECTED((generator != orig_generator && !Z_ISUNDEF(generator->retval)) || (generator->execute_data && (generator->execute_data->opline - 1)->opcode == ZEND_YIELD_FROM))) {
880 generator = zend_generator_get_current(orig_generator);
881 goto try_again;
882 }
883
884 orig_generator->flags &= ~(ZEND_GENERATOR_DO_INIT | ZEND_GENERATOR_IN_FIBER);
885 }
886 /* }}} */
887
zend_generator_ensure_initialized(zend_generator * generator)888 static inline void zend_generator_ensure_initialized(zend_generator *generator) /* {{{ */
889 {
890 if (UNEXPECTED(Z_TYPE(generator->value) == IS_UNDEF) && EXPECTED(generator->execute_data) && EXPECTED(generator->node.parent == NULL)) {
891 zend_generator_resume(generator);
892 generator->flags |= ZEND_GENERATOR_AT_FIRST_YIELD;
893 }
894 }
895 /* }}} */
896
zend_generator_rewind(zend_generator * generator)897 static inline void zend_generator_rewind(zend_generator *generator) /* {{{ */
898 {
899 zend_generator_ensure_initialized(generator);
900
901 if (!(generator->flags & ZEND_GENERATOR_AT_FIRST_YIELD)) {
902 zend_throw_exception(NULL, "Cannot rewind a generator that was already run", 0);
903 }
904 }
905 /* }}} */
906
907 /* {{{ Rewind the generator */
ZEND_METHOD(Generator,rewind)908 ZEND_METHOD(Generator, rewind)
909 {
910 zend_generator *generator;
911
912 ZEND_PARSE_PARAMETERS_NONE();
913
914 generator = (zend_generator *) Z_OBJ_P(ZEND_THIS);
915
916 zend_generator_rewind(generator);
917 }
918 /* }}} */
919
920 /* {{{ Check whether the generator is valid */
ZEND_METHOD(Generator,valid)921 ZEND_METHOD(Generator, valid)
922 {
923 zend_generator *generator;
924
925 ZEND_PARSE_PARAMETERS_NONE();
926
927 generator = (zend_generator *) Z_OBJ_P(ZEND_THIS);
928
929 zend_generator_ensure_initialized(generator);
930
931 zend_generator_get_current(generator);
932
933 RETURN_BOOL(EXPECTED(generator->execute_data != NULL));
934 }
935 /* }}} */
936
937 /* {{{ Get the current value */
ZEND_METHOD(Generator,current)938 ZEND_METHOD(Generator, current)
939 {
940 zend_generator *generator, *root;
941
942 ZEND_PARSE_PARAMETERS_NONE();
943
944 generator = (zend_generator *) Z_OBJ_P(ZEND_THIS);
945
946 zend_generator_ensure_initialized(generator);
947
948 root = zend_generator_get_current(generator);
949 if (EXPECTED(generator->execute_data != NULL && Z_TYPE(root->value) != IS_UNDEF)) {
950 RETURN_COPY_DEREF(&root->value);
951 }
952 }
953 /* }}} */
954
955 /* {{{ Get the current key */
ZEND_METHOD(Generator,key)956 ZEND_METHOD(Generator, key)
957 {
958 zend_generator *generator, *root;
959
960 ZEND_PARSE_PARAMETERS_NONE();
961
962 generator = (zend_generator *) Z_OBJ_P(ZEND_THIS);
963
964 zend_generator_ensure_initialized(generator);
965
966 root = zend_generator_get_current(generator);
967 if (EXPECTED(generator->execute_data != NULL && Z_TYPE(root->key) != IS_UNDEF)) {
968 RETURN_COPY_DEREF(&root->key);
969 }
970 }
971 /* }}} */
972
973 /* {{{ Advances the generator */
ZEND_METHOD(Generator,next)974 ZEND_METHOD(Generator, next)
975 {
976 zend_generator *generator;
977
978 ZEND_PARSE_PARAMETERS_NONE();
979
980 generator = (zend_generator *) Z_OBJ_P(ZEND_THIS);
981
982 zend_generator_ensure_initialized(generator);
983
984 zend_generator_resume(generator);
985 }
986 /* }}} */
987
988 /* {{{ Sends a value to the generator */
ZEND_METHOD(Generator,send)989 ZEND_METHOD(Generator, send)
990 {
991 zval *value;
992 zend_generator *generator, *root;
993
994 ZEND_PARSE_PARAMETERS_START(1, 1)
995 Z_PARAM_ZVAL(value)
996 ZEND_PARSE_PARAMETERS_END();
997
998 generator = (zend_generator *) Z_OBJ_P(ZEND_THIS);
999
1000 zend_generator_ensure_initialized(generator);
1001
1002 /* The generator is already closed, thus can't send anything */
1003 if (UNEXPECTED(!generator->execute_data)) {
1004 return;
1005 }
1006
1007 root = zend_generator_get_current(generator);
1008 /* Put sent value in the target VAR slot, if it is used */
1009 if (root->send_target && !(root->flags & ZEND_GENERATOR_CURRENTLY_RUNNING)) {
1010 ZVAL_COPY(root->send_target, value);
1011 }
1012
1013 zend_generator_resume(generator);
1014
1015 root = zend_generator_get_current(generator);
1016 if (EXPECTED(generator->execute_data)) {
1017 RETURN_COPY_DEREF(&root->value);
1018 }
1019 }
1020 /* }}} */
1021
1022 /* {{{ Throws an exception into the generator */
ZEND_METHOD(Generator,throw)1023 ZEND_METHOD(Generator, throw)
1024 {
1025 zval *exception;
1026 zend_generator *generator;
1027
1028 ZEND_PARSE_PARAMETERS_START(1, 1)
1029 Z_PARAM_OBJECT_OF_CLASS(exception, zend_ce_throwable);
1030 ZEND_PARSE_PARAMETERS_END();
1031
1032 Z_TRY_ADDREF_P(exception);
1033
1034 generator = (zend_generator *) Z_OBJ_P(ZEND_THIS);
1035
1036 zend_generator_ensure_initialized(generator);
1037
1038 if (generator->execute_data) {
1039 zend_generator *root = zend_generator_get_current(generator);
1040
1041 zend_generator_throw_exception(root, exception);
1042
1043 zend_generator_resume(generator);
1044
1045 root = zend_generator_get_current(generator);
1046 if (generator->execute_data) {
1047 RETURN_COPY_DEREF(&root->value);
1048 }
1049 } else {
1050 /* If the generator is already closed throw the exception in the
1051 * current context */
1052 zend_throw_exception_object(exception);
1053 }
1054 }
1055 /* }}} */
1056
1057 /* {{{ Retrieves the return value of the generator */
ZEND_METHOD(Generator,getReturn)1058 ZEND_METHOD(Generator, getReturn)
1059 {
1060 zend_generator *generator;
1061
1062 ZEND_PARSE_PARAMETERS_NONE();
1063
1064 generator = (zend_generator *) Z_OBJ_P(ZEND_THIS);
1065
1066 zend_generator_ensure_initialized(generator);
1067 if (UNEXPECTED(EG(exception))) {
1068 return;
1069 }
1070
1071 if (Z_ISUNDEF(generator->retval)) {
1072 /* Generator hasn't returned yet -> error! */
1073 zend_throw_exception(NULL,
1074 "Cannot get return value of a generator that hasn't returned", 0);
1075 return;
1076 }
1077
1078 ZVAL_COPY(return_value, &generator->retval);
1079 }
1080 /* }}} */
1081
1082 /* get_iterator implementation */
1083
zend_generator_iterator_dtor(zend_object_iterator * iterator)1084 static void zend_generator_iterator_dtor(zend_object_iterator *iterator) /* {{{ */
1085 {
1086 zval_ptr_dtor(&iterator->data);
1087 }
1088 /* }}} */
1089
zend_generator_iterator_valid(zend_object_iterator * iterator)1090 static int zend_generator_iterator_valid(zend_object_iterator *iterator) /* {{{ */
1091 {
1092 zend_generator *generator = (zend_generator*)Z_OBJ(iterator->data);
1093
1094 zend_generator_ensure_initialized(generator);
1095
1096 zend_generator_get_current(generator);
1097
1098 return generator->execute_data ? SUCCESS : FAILURE;
1099 }
1100 /* }}} */
1101
zend_generator_iterator_get_data(zend_object_iterator * iterator)1102 static zval *zend_generator_iterator_get_data(zend_object_iterator *iterator) /* {{{ */
1103 {
1104 zend_generator *generator = (zend_generator*)Z_OBJ(iterator->data), *root;
1105
1106 zend_generator_ensure_initialized(generator);
1107
1108 root = zend_generator_get_current(generator);
1109
1110 return &root->value;
1111 }
1112 /* }}} */
1113
zend_generator_iterator_get_key(zend_object_iterator * iterator,zval * key)1114 static void zend_generator_iterator_get_key(zend_object_iterator *iterator, zval *key) /* {{{ */
1115 {
1116 zend_generator *generator = (zend_generator*)Z_OBJ(iterator->data), *root;
1117
1118 zend_generator_ensure_initialized(generator);
1119
1120 root = zend_generator_get_current(generator);
1121
1122 if (EXPECTED(Z_TYPE(root->key) != IS_UNDEF)) {
1123 zval *zv = &root->key;
1124
1125 ZVAL_COPY_DEREF(key, zv);
1126 } else {
1127 ZVAL_NULL(key);
1128 }
1129 }
1130 /* }}} */
1131
zend_generator_iterator_move_forward(zend_object_iterator * iterator)1132 static void zend_generator_iterator_move_forward(zend_object_iterator *iterator) /* {{{ */
1133 {
1134 zend_generator *generator = (zend_generator*)Z_OBJ(iterator->data);
1135
1136 zend_generator_ensure_initialized(generator);
1137
1138 zend_generator_resume(generator);
1139 }
1140 /* }}} */
1141
zend_generator_iterator_rewind(zend_object_iterator * iterator)1142 static void zend_generator_iterator_rewind(zend_object_iterator *iterator) /* {{{ */
1143 {
1144 zend_generator *generator = (zend_generator*)Z_OBJ(iterator->data);
1145
1146 zend_generator_rewind(generator);
1147 }
1148 /* }}} */
1149
zend_generator_iterator_get_gc(zend_object_iterator * iterator,zval ** table,int * n)1150 static HashTable *zend_generator_iterator_get_gc(
1151 zend_object_iterator *iterator, zval **table, int *n)
1152 {
1153 *table = &iterator->data;
1154 *n = 1;
1155 return NULL;
1156 }
1157
1158 static const zend_object_iterator_funcs zend_generator_iterator_functions = {
1159 zend_generator_iterator_dtor,
1160 zend_generator_iterator_valid,
1161 zend_generator_iterator_get_data,
1162 zend_generator_iterator_get_key,
1163 zend_generator_iterator_move_forward,
1164 zend_generator_iterator_rewind,
1165 NULL,
1166 zend_generator_iterator_get_gc,
1167 };
1168
1169 /* by_ref is int due to Iterator API */
zend_generator_get_iterator(zend_class_entry * ce,zval * object,int by_ref)1170 zend_object_iterator *zend_generator_get_iterator(zend_class_entry *ce, zval *object, int by_ref) /* {{{ */
1171 {
1172 zend_object_iterator *iterator;
1173 zend_generator *generator = (zend_generator*)Z_OBJ_P(object);
1174
1175 if (!generator->execute_data) {
1176 zend_throw_exception(NULL, "Cannot traverse an already closed generator", 0);
1177 return NULL;
1178 }
1179
1180 if (UNEXPECTED(by_ref) && !(generator->execute_data->func->op_array.fn_flags & ZEND_ACC_RETURN_REFERENCE)) {
1181 zend_throw_exception(NULL, "You can only iterate a generator by-reference if it declared that it yields by-reference", 0);
1182 return NULL;
1183 }
1184
1185 iterator = emalloc(sizeof(zend_object_iterator));
1186 zend_iterator_init(iterator);
1187
1188 iterator->funcs = &zend_generator_iterator_functions;
1189 ZVAL_OBJ_COPY(&iterator->data, Z_OBJ_P(object));
1190
1191 return iterator;
1192 }
1193 /* }}} */
1194
zend_register_generator_ce(void)1195 void zend_register_generator_ce(void) /* {{{ */
1196 {
1197 zend_ce_generator = register_class_Generator(zend_ce_iterator);
1198 zend_ce_generator->create_object = zend_generator_create;
1199 /* get_iterator has to be assigned *after* implementing the interface */
1200 zend_ce_generator->get_iterator = zend_generator_get_iterator;
1201 zend_ce_generator->default_object_handlers = &zend_generator_handlers;
1202
1203 memcpy(&zend_generator_handlers, &std_object_handlers, sizeof(zend_object_handlers));
1204 zend_generator_handlers.free_obj = zend_generator_free_storage;
1205 zend_generator_handlers.dtor_obj = zend_generator_dtor_storage;
1206 zend_generator_handlers.get_gc = zend_generator_get_gc;
1207 zend_generator_handlers.clone_obj = NULL;
1208 zend_generator_handlers.get_constructor = zend_generator_get_constructor;
1209
1210 zend_ce_ClosedGeneratorException = register_class_ClosedGeneratorException(zend_ce_exception);
1211 }
1212 /* }}} */
1213