php-src/Zend/zend_generators.c
2024-01-10 22:19:23 +00:00

1144 lines
34 KiB
C

/*
+----------------------------------------------------------------------+
| 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 |
| license@zend.com so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Authors: Nikita Popov <nikic@php.net> |
| Bob Weinand <bobwei9@hotmail.com> |
+----------------------------------------------------------------------+
*/
#include "zend.h"
#include "zend_API.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"
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) {
/* -1 required because we want the last run opcode, not the next to-be-run one. */
uint32_t op_num = execute_data->opline - op_array->opcodes - 1;
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);
}
/* Free closure object */
if (EX_CALL_INFO() & ZEND_CALL_CLOSURE) {
OBJ_RELEASE(ZEND_CLOSURE_OBJECT(EX(func)));
}
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;
}
}
static void zend_generator_dtor_storage(zend_object *object) /* {{{ */
{
zend_generator *generator = (zend_generator*) object;
zend_execute_data *ex = generator->execute_data;
uint32_t op_num, try_catch_offset;
int i;
/* Generator is running in a suspended fiber.
* Will be dtor during fiber dtor */
if (zend_generator_get_current(generator)->flags & ZEND_GENERATOR_IN_FIBER) {
/* 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;
}
/* -1 required because we want the last run opcode, not the
* next to-be-run one. */
op_num = ex->opline - ex->func->op_array.opcodes - 1;
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;
ex->opline = &ex->func->op_array.opcodes[try_catch->finally_op];
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);
/* 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 the 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->opline--;
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);
}
generator->execute_data->opline++;
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 - 1;
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_YIELD(_FROM) already advance, so decrement opline to throw from correct place */
new_root->execute_data->opline--;
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 ? old_root : generator)->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) /* {{{ */
{
--generator->execute_data->opline;
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);
}
}
++generator->execute_data->opline;
return SUCCESS;
failure:
zval_ptr_dtor(&generator->values);
ZVAL_UNDEF(&generator->values);
++generator->execute_data->opline;
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;
}
/* 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;
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 */
generator->flags |= ZEND_GENERATOR_CURRENTLY_RUNNING
| (EG(active_fiber) ? ZEND_GENERATOR_IN_FIBER : 0);
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 - 1)->opcode == ZEND_YIELD_FROM))) {
generator = zend_generator_get_current(orig_generator);
goto try_again;
}
orig_generator->flags &= ~ZEND_GENERATOR_DO_INIT;
}
/* }}} */
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;
}
root = zend_generator_get_current(generator);
/* Put sent value in the target VAR slot, if it is used */
if (root->send_target && !(root->flags & ZEND_GENERATOR_CURRENTLY_RUNNING)) {
ZVAL_COPY(root->send_target, value);
}
zend_generator_resume(generator);
root = zend_generator_get_current(generator);
if (EXPECTED(generator->execute_data)) {
RETURN_COPY_DEREF(&root->value);
}
}
/* }}} */
/* {{{ Throws an exception into the generator */
ZEND_METHOD(Generator, throw)
{
zval *exception;
zend_generator *generator;
ZEND_PARSE_PARAMETERS_START(1, 1)
Z_PARAM_OBJECT_OF_CLASS(exception, zend_ce_throwable);
ZEND_PARSE_PARAMETERS_END();
Z_TRY_ADDREF_P(exception);
generator = (zend_generator *) Z_OBJ_P(ZEND_THIS);
zend_generator_ensure_initialized(generator);
if (generator->execute_data) {
zend_generator *root = zend_generator_get_current(generator);
zend_generator_throw_exception(root, exception);
zend_generator_resume(generator);
root = zend_generator_get_current(generator);
if (generator->execute_data) {
RETURN_COPY_DEREF(&root->value);
}
} else {
/* If the generator is already closed throw the exception in the
* current context */
zend_throw_exception_object(exception);
}
}
/* }}} */
/* {{{ Retrieves the return value of the generator */
ZEND_METHOD(Generator, getReturn)
{
zend_generator *generator;
ZEND_PARSE_PARAMETERS_NONE();
generator = (zend_generator *) Z_OBJ_P(ZEND_THIS);
zend_generator_ensure_initialized(generator);
if (UNEXPECTED(EG(exception))) {
return;
}
if (Z_ISUNDEF(generator->retval)) {
/* Generator hasn't returned yet -> error! */
zend_throw_exception(NULL,
"Cannot get return value of a generator that hasn't returned", 0);
return;
}
ZVAL_COPY(return_value, &generator->retval);
}
/* }}} */
/* get_iterator implementation */
static void zend_generator_iterator_dtor(zend_object_iterator *iterator) /* {{{ */
{
zval_ptr_dtor(&iterator->data);
}
/* }}} */
static zend_result zend_generator_iterator_valid(zend_object_iterator *iterator) /* {{{ */
{
zend_generator *generator = (zend_generator*)Z_OBJ(iterator->data);
zend_generator_ensure_initialized(generator);
zend_generator_get_current(generator);
return generator->execute_data ? SUCCESS : FAILURE;
}
/* }}} */
static zval *zend_generator_iterator_get_data(zend_object_iterator *iterator) /* {{{ */
{
zend_generator *generator = (zend_generator*)Z_OBJ(iterator->data), *root;
zend_generator_ensure_initialized(generator);
root = zend_generator_get_current(generator);
return &root->value;
}
/* }}} */
static void zend_generator_iterator_get_key(zend_object_iterator *iterator, zval *key) /* {{{ */
{
zend_generator *generator = (zend_generator*)Z_OBJ(iterator->data), *root;
zend_generator_ensure_initialized(generator);
root = zend_generator_get_current(generator);
if (EXPECTED(Z_TYPE(root->key) != IS_UNDEF)) {
zval *zv = &root->key;
ZVAL_COPY_DEREF(key, zv);
} else {
ZVAL_NULL(key);
}
}
/* }}} */
static void zend_generator_iterator_move_forward(zend_object_iterator *iterator) /* {{{ */
{
zend_generator *generator = (zend_generator*)Z_OBJ(iterator->data);
zend_generator_ensure_initialized(generator);
zend_generator_resume(generator);
}
/* }}} */
static void zend_generator_iterator_rewind(zend_object_iterator *iterator) /* {{{ */
{
zend_generator *generator = (zend_generator*)Z_OBJ(iterator->data);
zend_generator_rewind(generator);
}
/* }}} */
static HashTable *zend_generator_iterator_get_gc(
zend_object_iterator *iterator, zval **table, int *n)
{
*table = &iterator->data;
*n = 1;
return NULL;
}
static const zend_object_iterator_funcs zend_generator_iterator_functions = {
zend_generator_iterator_dtor,
zend_generator_iterator_valid,
zend_generator_iterator_get_data,
zend_generator_iterator_get_key,
zend_generator_iterator_move_forward,
zend_generator_iterator_rewind,
NULL,
zend_generator_iterator_get_gc,
};
/* by_ref is int due to Iterator API */
zend_object_iterator *zend_generator_get_iterator(zend_class_entry *ce, zval *object, int by_ref) /* {{{ */
{
zend_object_iterator *iterator;
zend_generator *generator = (zend_generator*)Z_OBJ_P(object);
if (!generator->execute_data) {
zend_throw_exception(NULL, "Cannot traverse an already closed generator", 0);
return NULL;
}
if (UNEXPECTED(by_ref) && !(generator->execute_data->func->op_array.fn_flags & ZEND_ACC_RETURN_REFERENCE)) {
zend_throw_exception(NULL, "You can only iterate a generator by-reference if it declared that it yields by-reference", 0);
return NULL;
}
iterator = emalloc(sizeof(zend_object_iterator));
zend_iterator_init(iterator);
iterator->funcs = &zend_generator_iterator_functions;
ZVAL_OBJ_COPY(&iterator->data, Z_OBJ_P(object));
return iterator;
}
/* }}} */
void zend_register_generator_ce(void) /* {{{ */
{
zend_ce_generator = register_class_Generator(zend_ce_iterator);
zend_ce_generator->create_object = zend_generator_create;
/* get_iterator has to be assigned *after* implementing the interface */
zend_ce_generator->get_iterator = zend_generator_get_iterator;
zend_ce_generator->default_object_handlers = &zend_generator_handlers;
memcpy(&zend_generator_handlers, &std_object_handlers, sizeof(zend_object_handlers));
zend_generator_handlers.free_obj = zend_generator_free_storage;
zend_generator_handlers.dtor_obj = zend_generator_dtor_storage;
zend_generator_handlers.get_gc = zend_generator_get_gc;
zend_generator_handlers.clone_obj = NULL;
zend_generator_handlers.get_constructor = zend_generator_get_constructor;
zend_ce_ClosedGeneratorException = register_class_ClosedGeneratorException(zend_ce_exception);
}
/* }}} */