php-src/Zend/zend_generators.c
2018-09-28 19:17:53 +02:00

1255 lines
37 KiB
C

/*
+----------------------------------------------------------------------+
| Zend Engine |
+----------------------------------------------------------------------+
| Copyright (c) 1998-2018 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"
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_TYPE(call->This) == IS_UNDEF) ?
(zend_class_entry*)Z_OBJ(call->This) : NULL,
(Z_TYPE(call->This) != IS_UNDEF) ?
Z_OBJ(call->This) : NULL);
memcpy(((zval*)new_call) + ZEND_CALL_FRAME_SLOT, ((zval*)call) + ZEND_CALL_FRAME_SLOT, ZEND_CALL_NUM_ARGS(call) * sizeof(zval));
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 void zend_generator_cleanup_unfinished_execution(
zend_generator *generator, uint32_t catch_op_num) /* {{{ */
{
zend_execute_data *execute_data = generator->execute_data;
if (execute_data->opline != execute_data->func->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 - execute_data->func->op_array.opcodes - 1;
if (UNEXPECTED(generator->frozen_call_stack)) {
zend_generator_restore_call_stack(generator);
}
zend_cleanup_unfinished_execution(execute_data, op_num, catch_op_num);
}
}
/* }}} */
ZEND_API void zend_generator_close(zend_generator *generator, zend_bool finished_execution) /* {{{ */
{
if (EXPECTED(generator->execute_data)) {
zend_execute_data *execute_data = generator->execute_data;
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_RELEASE_THIS) &&
EXPECTED(GC_TYPE(Z_OBJ(execute_data->This)) == IS_OBJECT)) {
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(generator->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, 0);
}
/* Free closure object */
if ((EX_CALL_INFO() & ZEND_CALL_CLOSURE) &&
EXPECTED(GC_TYPE(ZEND_CLOSURE_OBJECT(EX(func))) == IS_OBJECT)) {
OBJ_RELEASE(ZEND_CLOSURE_OBJECT(EX(func)));
}
/* Free GC buffer. GC for closed generators doesn't need an allocated buffer */
if (generator->gc_buffer) {
efree(generator->gc_buffer);
generator->gc_buffer = NULL;
}
efree(generator->execute_data);
generator->execute_data = NULL;
}
}
/* }}} */
static zend_generator *zend_generator_get_child(zend_generator_node *node, zend_generator *leaf);
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, finally_op_num, finally_op_end;
int i;
/* 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);
}
if (EXPECTED(generator->node.children == 0)) {
zend_generator *root = generator->node.ptr.root, *next;
while (UNEXPECTED(root != generator)) {
next = zend_generator_get_child(&root->node, generator);
generator->node.ptr.root = next;
next->node.parent = NULL;
OBJ_RELEASE(&root->std);
root = next;
}
}
if (EXPECTED(!ex) || EXPECTED(!(ex->func->op_array.fn_flags & ZEND_ACC_HAS_FINALLY_BLOCK))
|| CG(unclean_shutdown)) {
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;
/* Find next finally block */
finally_op_num = 0;
finally_op_end = 0;
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->finally_op) {
finally_op_num = try_catch->finally_op;
finally_op_end = try_catch->finally_end;
}
}
/* If a finally block was found we jump directly to it and
* resume the generator. */
if (finally_op_num) {
zval *fast_call;
zend_generator_cleanup_unfinished_execution(generator, finally_op_num);
fast_call = ZEND_CALL_VAR(ex, ex->func->op_array.opcodes[finally_op_end].op1.var);
Z_OBJ_P(fast_call) = EG(exception);
EG(exception) = NULL;
Z_OPLINE_NUM_P(fast_call) = (uint32_t)-1;
ex->opline = &ex->func->op_array.opcodes[finally_op_num];
generator->flags |= ZEND_GENERATOR_FORCED_CLOSE;
zend_generator_resume(generator);
}
}
/* }}} */
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);
if (generator->iterator) {
zend_iterator_dtor(generator->iterator);
}
}
/* }}} */
static uint32_t calc_gc_buffer_size(zend_generator *generator) /* {{{ */
{
uint32_t size = 4; /* value, key, retval, values */
if (generator->execute_data) {
zend_execute_data *execute_data = generator->execute_data;
zend_op_array *op_array = &EX(func)->op_array;
/* Compiled variables */
if (!(EX_CALL_INFO() & ZEND_CALL_HAS_SYMBOL_TABLE)) {
size += op_array->last_var;
}
/* Extra args */
if (EX_CALL_INFO() & ZEND_CALL_FREE_EXTRA_ARGS) {
size += EX_NUM_ARGS() - op_array->num_args;
}
size += Z_TYPE(execute_data->This) == IS_OBJECT; /* $this */
size += (EX_CALL_INFO() & ZEND_CALL_CLOSURE) != 0; /* Closure object */
/* Live vars */
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 i, op_num = execute_data->opline - op_array->opcodes - 1;
for (i = 0; i < op_array->last_live_range; i++) {
const zend_live_range *range = &op_array->live_range[i];
if (range->start > op_num) {
/* Further ranges will not be relevant... */
break;
} else if (op_num < range->end) {
/* LIVE_ROPE and LIVE_SILENCE not relevant for GC */
uint32_t kind = range->var & ZEND_LIVE_MASK;
if (kind == ZEND_LIVE_TMPVAR || kind == ZEND_LIVE_LOOP) {
size++;
}
}
}
}
/* Yield from root references */
if (generator->node.children == 0) {
zend_generator *root = generator->node.ptr.root;
while (root != generator) {
root = zend_generator_get_child(&root->node, generator);
size++;
}
}
}
return size;
}
/* }}} */
static HashTable *zend_generator_get_gc(zval *object, zval **table, int *n) /* {{{ */
{
zend_generator *generator = (zend_generator*) Z_OBJ_P(object);
zend_execute_data *execute_data = generator->execute_data;
zend_op_array *op_array;
zval *gc_buffer;
uint32_t gc_buffer_size;
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;
}
op_array = &EX(func)->op_array;
gc_buffer_size = calc_gc_buffer_size(generator);
if (generator->gc_buffer_size < gc_buffer_size) {
generator->gc_buffer = safe_erealloc(generator->gc_buffer, sizeof(zval), gc_buffer_size, 0);
generator->gc_buffer_size = gc_buffer_size;
}
*n = gc_buffer_size;
*table = gc_buffer = generator->gc_buffer;
ZVAL_COPY_VALUE(gc_buffer++, &generator->value);
ZVAL_COPY_VALUE(gc_buffer++, &generator->key);
ZVAL_COPY_VALUE(gc_buffer++, &generator->retval);
ZVAL_COPY_VALUE(gc_buffer++, &generator->values);
if (!(EX_CALL_INFO() & ZEND_CALL_HAS_SYMBOL_TABLE)) {
uint32_t i, num_cvs = EX(func)->op_array.last_var;
for (i = 0; i < num_cvs; i++) {
ZVAL_COPY_VALUE(gc_buffer++, EX_VAR_NUM(i));
}
}
if (EX_CALL_INFO() & ZEND_CALL_FREE_EXTRA_ARGS) {
zval *zv = EX_VAR_NUM(op_array->last_var + op_array->T);
zval *end = zv + (EX_NUM_ARGS() - op_array->num_args);
while (zv != end) {
ZVAL_COPY_VALUE(gc_buffer++, zv++);
}
}
if (Z_TYPE(execute_data->This) == IS_OBJECT) {
ZVAL_OBJ(gc_buffer++, Z_OBJ(execute_data->This));
}
if (EX_CALL_INFO() & ZEND_CALL_CLOSURE) {
ZVAL_OBJ(gc_buffer++, ZEND_CLOSURE_OBJECT(EX(func)));
}
if (execute_data->opline != op_array->opcodes) {
uint32_t i, op_num = execute_data->opline - op_array->opcodes - 1;
for (i = 0; i < op_array->last_live_range; i++) {
const zend_live_range *range = &op_array->live_range[i];
if (range->start > op_num) {
break;
} else if (op_num < range->end) {
uint32_t kind = range->var & ZEND_LIVE_MASK;
uint32_t var_num = range->var & ~ZEND_LIVE_MASK;
zval *var = EX_VAR(var_num);
if (kind == ZEND_LIVE_TMPVAR || kind == ZEND_LIVE_LOOP) {
ZVAL_COPY_VALUE(gc_buffer++, var);
}
}
}
}
if (generator->node.children == 0) {
zend_generator *root = generator->node.ptr.root;
while (root != generator) {
ZVAL_OBJ(gc_buffer++, &root->std);
root = zend_generator_get_child(&root->node, generator);
}
}
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;
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 = generator;
zend_object_std_init(&generator->std, class_type);
generator->std.handlers = &zend_generator_handlers;
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_generator *root = (generator->node.children < 1 ? generator : generator->node.ptr.leaf)->node.ptr.root;
zend_execute_data *prev = ptr->prev_execute_data;
if (generator->node.parent != root) {
do {
generator->execute_data->prev_execute_data = prev;
prev = generator->execute_data;
generator = generator->node.parent;
} while (generator->node.parent != root);
}
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);
/* 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);
}
/* 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));
}
generator->execute_data->opline++;
EG(current_execute_data) = original_execute_data;
}
static zend_generator *zend_generator_get_child(zend_generator_node *node, zend_generator *leaf)
{
if (node->children == 0) {
return NULL;
} else if (node->children == 1) {
return node->child.single.child;
} else {
return zend_hash_index_find_ptr(node->child.ht, (zend_ulong) leaf);
}
}
static zend_generator_node *zend_generator_search_multi_children_node(zend_generator_node *node)
{
while (node->children == 1) {
node = &node->child.single.child->node;
}
return node->children > 1 ? node : NULL;
}
static void zend_generator_add_single_child(zend_generator_node *node, zend_generator *child, zend_generator *leaf)
{
if (node->children == 0) {
node->child.single.leaf = leaf;
node->child.single.child = child;
} else {
if (node->children == 1) {
HashTable *ht = emalloc(sizeof(HashTable));
zend_hash_init(ht, 0, NULL, NULL, 0);
zend_hash_index_add_ptr(ht,
(zend_ulong) node->child.single.leaf, node->child.single.child);
node->child.ht = ht;
}
zend_hash_index_add_ptr(node->child.ht, (zend_ulong) leaf, child);
}
node->children++;
}
static void zend_generator_merge_child_nodes(zend_generator_node *dest, zend_generator_node *src, zend_generator *child)
{
zend_ulong leaf;
ZEND_ASSERT(src->children > 1);
ZEND_HASH_FOREACH_NUM_KEY(src->child.ht, leaf) {
zend_generator_add_single_child(dest, child, (zend_generator *) leaf);
} ZEND_HASH_FOREACH_END();
}
/* Pay attention so that the root of each subtree of the Generators tree is referenced
* once per leaf */
static void zend_generator_add_child(zend_generator *generator, zend_generator *child)
{
zend_generator *leaf = child->node.children ? child->node.ptr.leaf : child;
zend_generator_node *multi_children_node;
zend_bool was_leaf = generator->node.children == 0;
if (was_leaf) {
zend_generator *next = generator->node.parent;
leaf->node.ptr.root = generator->node.ptr.root;
GC_ADDREF(&generator->std); /* we need to increment the generator refcount here as it became integrated into the tree (no leaf), but we must not increment the refcount of the *whole* path in tree */
generator->node.ptr.leaf = leaf;
while (next) {
if (next->node.children > 1) {
zend_generator *child = zend_hash_index_find_ptr(next->node.child.ht, (zend_ulong) generator);
zend_hash_index_del(next->node.child.ht, (zend_ulong) generator);
zend_hash_index_add_ptr(next->node.child.ht, (zend_ulong) leaf, child);
}
next->node.ptr.leaf = leaf;
next = next->node.parent;
}
} else if (generator->node.children == 1) {
multi_children_node = zend_generator_search_multi_children_node(&generator->node);
if (multi_children_node) {
generator->node.children = 0;
zend_generator_merge_child_nodes(&generator->node, multi_children_node, generator->node.child.single.child);
}
}
if (!was_leaf) {
multi_children_node = zend_generator_search_multi_children_node(&child->node);
} else {
multi_children_node = (zend_generator_node *) 0x1;
}
{
zend_generator *parent = generator->node.parent, *cur = generator;
if (multi_children_node > (zend_generator_node *) 0x1) {
zend_generator_merge_child_nodes(&generator->node, multi_children_node, child);
} else {
zend_generator_add_single_child(&generator->node, child, leaf);
}
while (parent) {
if (parent->node.children > 1) {
if (multi_children_node == (zend_generator_node *) 0x1) {
multi_children_node = zend_generator_search_multi_children_node(&child->node);
}
if (multi_children_node) {
zend_generator_merge_child_nodes(&parent->node, multi_children_node, cur);
} else {
zend_generator_add_single_child(&parent->node, cur, leaf);
}
}
cur = parent;
parent = parent->node.parent;
}
}
}
void zend_generator_yield_from(zend_generator *generator, zend_generator *from)
{
zend_generator_add_child(from, generator);
generator->node.parent = from;
zend_generator_get_current(generator);
GC_DELREF(&from->std);
}
ZEND_API zend_generator *zend_generator_update_current(zend_generator *generator, zend_generator *leaf)
{
zend_generator *old_root, *root = leaf->node.ptr.root;
/* generator at the root had stopped */
if (root != generator) {
old_root = root;
root = zend_generator_get_child(&root->node, leaf);
} else {
old_root = NULL;
}
while (!root->execute_data && root != generator) {
OBJ_RELEASE(&old_root->std);
old_root = root;
root = zend_generator_get_child(&root->node, leaf);
}
if (root->node.parent) {
if (root->node.parent->execute_data == NULL) {
if (EXPECTED(EG(exception) == NULL)) {
zend_op *yield_from = (zend_op *) root->execute_data->opline - 1;
if (yield_from->opcode == ZEND_YIELD_FROM) {
if (Z_ISUNDEF(root->node.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) = root->execute_data;
if (root == generator) {
root->execute_data->prev_execute_data = original_execute_data;
} else {
root->execute_data->prev_execute_data = &generator->execute_fake;
generator->execute_fake.prev_execute_data = original_execute_data;
}
root->execute_data->opline--; /* ZEND_YIELD(_FROM) already advance, so decrement opline to throw from correct place */
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)) {
leaf->node.ptr.root = root;
root->node.parent = NULL;
if (old_root) {
OBJ_RELEASE(&old_root->std);
}
zend_generator_resume(leaf);
return leaf->node.ptr.root; /* this may be updated during zend_generator_resume! */
}
} else {
zval_ptr_dtor(&root->value);
ZVAL_COPY(&root->value, &root->node.parent->value);
ZVAL_COPY(ZEND_CALL_VAR(root->execute_data, yield_from->result.var), &root->node.parent->retval);
}
}
}
root->node.parent = NULL;
} else {
do {
root = root->node.parent;
GC_ADDREF(&root->std);
} while (root->node.parent);
}
}
leaf->node.ptr.root = root;
if (old_root) {
OBJ_RELEASE(&old_root->std);
}
return root;
}
static int 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);
Bucket *p;
do {
if (UNEXPECTED(pos >= ht->nNumUsed)) {
/* Reached end of array */
goto failure;
}
p = &ht->arData[pos];
value = &p->val;
if (Z_TYPE_P(value) == IS_INDIRECT) {
value = Z_INDIRECT_P(value);
}
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 exception;
}
}
if (iter->funcs->valid(iter) == FAILURE) {
/* reached end of iteration */
goto failure;
}
value = iter->funcs->get_current_data(iter);
if (UNEXPECTED(EG(exception) != NULL)) {
goto exception;
} else if (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 exception;
}
} else {
ZVAL_LONG(&generator->key, iter->index);
}
}
return SUCCESS;
exception:
zend_rethrow_exception(generator->execute_data);
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 */
return;
}
if (UNEXPECTED(!Z_ISUNDEF(generator->values))) {
if (EXPECTED(zend_generator_get_next_delegated_value(generator) == SUCCESS)) {
return;
}
/* If there are no more deletegated values, resume the generator
* after the "yield from" expression. */
}
/* 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);
/* Set executor globals */
EG(current_execute_data) = generator->execute_data;
/* 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;
}
if (UNEXPECTED(generator->frozen_call_stack)) {
/* Restore frozen call-stack */
zend_generator_restore_call_stack(generator);
}
/* Resume execution */
generator->flags |= ZEND_GENERATOR_CURRENTLY_RUNNING;
zend_execute_ex(generator->execute_data);
generator->flags &= ~ZEND_GENERATOR_CURRENTLY_RUNNING;
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;
/* 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) &&
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);
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;
}
}
}
/* }}} */
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)) {
generator->flags |= ZEND_GENERATOR_DO_INIT;
zend_generator_resume(generator);
generator->flags &= ~ZEND_GENERATOR_DO_INIT;
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);
}
}
/* }}} */
/* {{{ proto void Generator::rewind()
* Rewind the generator */
ZEND_METHOD(Generator, rewind)
{
zend_generator *generator;
if (zend_parse_parameters_none() == FAILURE) {
return;
}
generator = (zend_generator *) Z_OBJ_P(getThis());
zend_generator_rewind(generator);
}
/* }}} */
/* {{{ proto bool Generator::valid()
* Check whether the generator is valid */
ZEND_METHOD(Generator, valid)
{
zend_generator *generator;
if (zend_parse_parameters_none() == FAILURE) {
return;
}
generator = (zend_generator *) Z_OBJ_P(getThis());
zend_generator_ensure_initialized(generator);
zend_generator_get_current(generator);
RETURN_BOOL(EXPECTED(generator->execute_data != NULL));
}
/* }}} */
/* {{{ proto mixed Generator::current()
* Get the current value */
ZEND_METHOD(Generator, current)
{
zend_generator *generator, *root;
if (zend_parse_parameters_none() == FAILURE) {
return;
}
generator = (zend_generator *) Z_OBJ_P(getThis());
zend_generator_ensure_initialized(generator);
root = zend_generator_get_current(generator);
if (EXPECTED(generator->execute_data != NULL && Z_TYPE(root->value) != IS_UNDEF)) {
zval *value = &root->value;
ZVAL_COPY_DEREF(return_value, value);
}
}
/* }}} */
/* {{{ proto mixed Generator::key()
* Get the current key */
ZEND_METHOD(Generator, key)
{
zend_generator *generator, *root;
if (zend_parse_parameters_none() == FAILURE) {
return;
}
generator = (zend_generator *) Z_OBJ_P(getThis());
zend_generator_ensure_initialized(generator);
root = zend_generator_get_current(generator);
if (EXPECTED(generator->execute_data != NULL && Z_TYPE(root->key) != IS_UNDEF)) {
zval *key = &root->key;
ZVAL_COPY_DEREF(return_value, key);
}
}
/* }}} */
/* {{{ proto void Generator::next()
* Advances the generator */
ZEND_METHOD(Generator, next)
{
zend_generator *generator;
if (zend_parse_parameters_none() == FAILURE) {
return;
}
generator = (zend_generator *) Z_OBJ_P(getThis());
zend_generator_ensure_initialized(generator);
zend_generator_resume(generator);
}
/* }}} */
/* {{{ proto mixed Generator::send(mixed value)
* 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(getThis());
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) {
ZVAL_COPY(root->send_target, value);
}
zend_generator_resume(generator);
root = zend_generator_get_current(generator);
if (EXPECTED(generator->execute_data)) {
zval *value = &root->value;
ZVAL_COPY_DEREF(return_value, value);
}
}
/* }}} */
/* {{{ proto mixed Generator::throw(Exception exception)
* Throws an exception into the generator */
ZEND_METHOD(Generator, throw)
{
zval *exception;
zend_generator *generator;
ZEND_PARSE_PARAMETERS_START(1, 1)
Z_PARAM_ZVAL(exception)
ZEND_PARSE_PARAMETERS_END();
Z_TRY_ADDREF_P(exception);
generator = (zend_generator *) Z_OBJ_P(getThis());
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) {
zval *value = &root->value;
ZVAL_COPY_DEREF(return_value, value);
}
} else {
/* If the generator is already closed throw the exception in the
* current context */
zend_throw_exception_object(exception);
}
}
/* }}} */
/* {{{ proto mixed Generator::getReturn()
* Retrieves the return value of the generator */
ZEND_METHOD(Generator, getReturn)
{
zend_generator *generator;
if (zend_parse_parameters_none() == FAILURE) {
return;
}
generator = (zend_generator *) Z_OBJ_P(getThis());
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);
}
/* }}} */
/* {{{ proto Generator::__wakeup()
* Throws an Exception as generators can't be serialized */
ZEND_METHOD(Generator, __wakeup)
{
/* Just specifying the zend_class_unserialize_deny handler is not enough,
* because it is only invoked for C unserialization. For O the error has
* to be thrown in __wakeup. */
if (zend_parse_parameters_none() == FAILURE) {
return;
}
zend_throw_exception(NULL, "Unserialization of 'Generator' is not allowed", 0);
}
/* }}} */
/* get_iterator implementation */
static void zend_generator_iterator_dtor(zend_object_iterator *iterator) /* {{{ */
{
zend_generator *generator = (zend_generator*)Z_OBJ(iterator->data);
generator->iterator = NULL;
zval_ptr_dtor(&iterator->data);
}
/* }}} */
static int 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 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_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 = generator->iterator = emalloc(sizeof(zend_object_iterator));
zend_iterator_init(iterator);
iterator->funcs = &zend_generator_iterator_functions;
ZVAL_COPY(&iterator->data, object);
return iterator;
}
/* }}} */
ZEND_BEGIN_ARG_INFO(arginfo_generator_void, 0)
ZEND_END_ARG_INFO()
ZEND_BEGIN_ARG_INFO_EX(arginfo_generator_send, 0, 0, 1)
ZEND_ARG_INFO(0, value)
ZEND_END_ARG_INFO()
ZEND_BEGIN_ARG_INFO_EX(arginfo_generator_throw, 0, 0, 1)
ZEND_ARG_INFO(0, exception)
ZEND_END_ARG_INFO()
static const zend_function_entry generator_functions[] = {
ZEND_ME(Generator, rewind, arginfo_generator_void, ZEND_ACC_PUBLIC)
ZEND_ME(Generator, valid, arginfo_generator_void, ZEND_ACC_PUBLIC)
ZEND_ME(Generator, current, arginfo_generator_void, ZEND_ACC_PUBLIC)
ZEND_ME(Generator, key, arginfo_generator_void, ZEND_ACC_PUBLIC)
ZEND_ME(Generator, next, arginfo_generator_void, ZEND_ACC_PUBLIC)
ZEND_ME(Generator, send, arginfo_generator_send, ZEND_ACC_PUBLIC)
ZEND_ME(Generator, throw, arginfo_generator_throw, ZEND_ACC_PUBLIC)
ZEND_ME(Generator, getReturn,arginfo_generator_void, ZEND_ACC_PUBLIC)
ZEND_ME(Generator, __wakeup, arginfo_generator_void, ZEND_ACC_PUBLIC)
ZEND_FE_END
};
void zend_register_generator_ce(void) /* {{{ */
{
zend_class_entry ce;
INIT_CLASS_ENTRY(ce, "Generator", generator_functions);
zend_ce_generator = zend_register_internal_class(&ce);
zend_ce_generator->ce_flags |= ZEND_ACC_FINAL;
zend_ce_generator->create_object = zend_generator_create;
zend_ce_generator->serialize = zend_class_serialize_deny;
zend_ce_generator->unserialize = zend_class_unserialize_deny;
/* get_iterator has to be assigned *after* implementing the inferface */
zend_class_implements(zend_ce_generator, 1, zend_ce_iterator);
zend_ce_generator->get_iterator = zend_generator_get_iterator;
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;
INIT_CLASS_ENTRY(ce, "ClosedGeneratorException", NULL);
zend_ce_ClosedGeneratorException = zend_register_internal_class_ex(&ce, zend_ce_exception);
}
/* }}} */
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* indent-tabs-mode: t
* End:
* vim600: sw=4 ts=4 fdm=marker
* vim<600: sw=4 ts=4
*/