php-src/Zend/zend_generators.c
2014-05-25 20:04:35 +08:00

743 lines
22 KiB
C

/*
+----------------------------------------------------------------------+
| Zend Engine |
+----------------------------------------------------------------------+
| Copyright (c) 1998-2014 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> |
+----------------------------------------------------------------------+
*/
/* $Id$ */
#include "zend.h"
#include "zend_API.h"
#include "zend_interfaces.h"
#include "zend_exceptions.h"
#include "zend_generators.h"
ZEND_API zend_class_entry *zend_ce_generator;
static zend_object_handlers zend_generator_handlers;
static zend_object *zend_generator_create(zend_class_entry *class_type TSRMLS_DC);
static void zend_generator_cleanup_unfinished_execution(zend_generator *generator TSRMLS_DC) /* {{{ */
{
zend_execute_data *execute_data = generator->execute_data;
zend_op_array *op_array = execute_data->op_array;
if (generator->send_target) {
if (Z_REFCOUNTED_P(generator->send_target)) Z_DELREF_P(generator->send_target);
generator->send_target = NULL;
}
/* Manually free loop variables, as execution couldn't reach their
* SWITCH_FREE / FREE opcodes. */
{
/* -1 required because we want the last run opcode, not the
* next to-be-run one. */
zend_uint op_num = execute_data->opline - op_array->opcodes - 1;
int i;
for (i = 0; i < op_array->last_brk_cont; ++i) {
zend_brk_cont_element *brk_cont = op_array->brk_cont_array + i;
if (brk_cont->start < 0) {
continue;
} else if (brk_cont->start > op_num) {
break;
} else if (brk_cont->brk > op_num) {
zend_op *brk_opline = op_array->opcodes + brk_cont->brk;
switch (brk_opline->opcode) {
case ZEND_SWITCH_FREE:
{
zval *var = EX_VAR_2(execute_data, brk_opline->op1.var);
zval_ptr_dtor(var);
}
break;
case ZEND_FREE:
{
zval *var = EX_VAR_2(execute_data, brk_opline->op1.var);
zval_dtor(var);
}
break;
}
}
}
}
/* Clear any backed up stack arguments */
{
zval *ptr = generator->stack->top - 1;
zval *end = zend_vm_stack_frame_base(execute_data);
for (; ptr >= end; --ptr) {
zval_ptr_dtor((zval*) ptr);
}
}
/* If yield was used as a function argument there may be active
* method calls those objects need to be freed */
while (execute_data->call >= execute_data->call_slots) {
if (execute_data->call->object) {
OBJ_RELEASE(execute_data->call->object);
}
execute_data->call--;
}
}
/* }}} */
ZEND_API void zend_generator_close(zend_generator *generator, zend_bool finished_execution TSRMLS_DC) /* {{{ */
{
if (Z_TYPE(generator->value) != IS_UNDEF) {
zval_ptr_dtor(&generator->value);
ZVAL_UNDEF(&generator->value);
}
if (Z_TYPE(generator->key) != IS_UNDEF) {
zval_ptr_dtor(&generator->key);
ZVAL_UNDEF(&generator->key);
}
if (generator->execute_data) {
zend_execute_data *execute_data = generator->execute_data;
zend_op_array *op_array = execute_data->op_array;
if (!execute_data->symbol_table) {
zend_free_compiled_variables(execute_data TSRMLS_CC);
} else {
zend_clean_and_cache_symbol_table(execute_data->symbol_table TSRMLS_CC);
}
if (execute_data->object) {
OBJ_RELEASE(execute_data->object);
}
/* A fatal error / die occurred during the generator execution. Trying to clean
* up the stack may not be safe in this case. */
if (CG(unclean_shutdown)) {
return;
}
/* We have added an additional stack frame in prev_execute_data, so we
* have to free it. It also contains the arguments passed to the
* generator (for func_get_args) so those have to be freed too. */
{
zend_execute_data *prev_execute_data = execute_data->prev_execute_data;
zval *arguments = prev_execute_data->function_state.arguments;
if (arguments) {
int arguments_count = Z_LVAL_P(arguments);
zval *arguments_start = arguments - arguments_count;
int i;
for (i = 0; i < arguments_count; ++i) {
zval_ptr_dtor(arguments_start + i);
}
}
}
/* Some cleanups are only necessary if the generator was closued
* before it could finish execution (reach a return statement). */
if (!finished_execution) {
zend_generator_cleanup_unfinished_execution(generator TSRMLS_CC);
}
/* Free a clone of closure */
if (op_array->fn_flags & ZEND_ACC_CLOSURE) {
destroy_op_array(op_array TSRMLS_CC);
efree(op_array);
}
efree(generator->stack);
generator->execute_data = NULL;
}
}
/* }}} */
static void zend_generator_dtor_storage(zend_object *object TSRMLS_DC) /* {{{ */
{
zend_generator *generator = (zend_generator*) object;
zend_execute_data *ex = generator->execute_data;
zend_uint op_num, finally_op_num;
int i;
if (!ex || !ex->op_array->has_finally_block) {
return;
}
/* -1 required because we want the last run opcode, not the
* next to-be-run one. */
op_num = ex->opline - ex->op_array->opcodes - 1;
/* Find next finally block */
finally_op_num = 0;
for (i = 0; i < ex->op_array->last_try_catch; i++) {
zend_try_catch_element *try_catch = &ex->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;
}
}
/* If a finally block was found we jump directly to it and
* resume the generator. */
if (finally_op_num) {
ex->opline = &ex->op_array->opcodes[finally_op_num];
ex->fast_ret = NULL;
generator->flags |= ZEND_GENERATOR_FORCED_CLOSE;
zend_generator_resume(generator TSRMLS_CC);
}
}
/* }}} */
static void zend_generator_free_storage(zend_object *object TSRMLS_DC) /* {{{ */
{
zend_generator *generator = (zend_generator*) object;
zend_generator_close(generator, 0 TSRMLS_CC);
zend_object_std_dtor(&generator->std TSRMLS_CC);
if (generator->iterator) {
zend_iterator_dtor(generator->iterator TSRMLS_CC);
}
}
/* }}} */
static zend_object *zend_generator_create(zend_class_entry *class_type TSRMLS_DC) /* {{{ */
{
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;
zend_object_std_init(&generator->std, class_type TSRMLS_CC);
generator->std.handlers = &zend_generator_handlers;
return (zend_object*)generator;
}
/* }}} */
static int copy_closure_static_var(zval *var TSRMLS_DC, int num_args, va_list args, zend_hash_key *key) /* {{{ */
{
HashTable *target = va_arg(args, HashTable *);
SEPARATE_ZVAL_TO_MAKE_IS_REF(var);
Z_ADDREF_P(var);
zend_hash_update(target, key->key, var);
return 0;
}
/* }}} */
/* Requires globals EG(scope), EG(current_scope), EG(This),
* EG(active_symbol_table) and EG(current_execute_data). */
ZEND_API void zend_generator_create_zval(zend_op_array *op_array, zval *return_value TSRMLS_DC) /* {{{ */
{
zend_generator *generator;
zend_execute_data *current_execute_data;
zend_op **opline_ptr;
zend_array *current_symbol_table;
zend_execute_data *execute_data;
zend_vm_stack current_stack = EG(argument_stack);
/* Create a clone of closure, because it may be destroyed */
if (op_array->fn_flags & ZEND_ACC_CLOSURE) {
zend_op_array *op_array_copy = (zend_op_array*)emalloc(sizeof(zend_op_array));
*op_array_copy = *op_array;
(*op_array->refcount)++;
op_array->run_time_cache = NULL;
if (op_array->static_variables) {
ALLOC_HASHTABLE(op_array_copy->static_variables);
zend_hash_init(
op_array_copy->static_variables,
zend_hash_num_elements(op_array->static_variables),
NULL, ZVAL_PTR_DTOR, 0
);
zend_hash_apply_with_arguments(
op_array->static_variables TSRMLS_CC,
copy_closure_static_var, 1,
op_array_copy->static_variables
);
}
op_array = op_array_copy;
}
/* Create new execution context. We have to back up and restore
* EG(current_execute_data), EG(opline_ptr) and EG(active_symbol_table)
* here because the function modifies or uses them */
current_execute_data = EG(current_execute_data);
opline_ptr = EG(opline_ptr);
current_symbol_table = EG(active_symbol_table);
EG(active_symbol_table) = NULL;
execute_data = zend_create_execute_data_from_op_array(op_array, return_value, VM_FRAME_TOP_FUNCTION TSRMLS_CC);
EG(active_symbol_table) = current_symbol_table;
EG(current_execute_data) = current_execute_data;
EG(opline_ptr) = opline_ptr;
object_init_ex(return_value, zend_ce_generator);
if (Z_OBJ(EG(This))) {
Z_ADDREF(EG(This));
}
/* Save execution context in generator object. */
execute_data->prev_execute_data->object = Z_OBJ_P(return_value);
generator = (zend_generator *) Z_OBJ_P(return_value);
generator->execute_data = execute_data;
generator->stack = EG(argument_stack);
EG(argument_stack) = current_stack;
/* EX(return_value) keeps pointer to zend_object (not a real zval) */
execute_data->return_value = (zval*)generator;
}
/* }}} */
static zend_function *zend_generator_get_constructor(zend_object *object TSRMLS_DC) /* {{{ */
{
zend_error(E_RECOVERABLE_ERROR, "The \"Generator\" class is reserved for internal use and cannot be manually instantiated");
return NULL;
}
/* }}} */
ZEND_API void zend_generator_resume(zend_generator *generator TSRMLS_DC) /* {{{ */
{
/* The generator is already closed, thus can't resume */
if (!generator->execute_data) {
return;
}
if (generator->flags & ZEND_GENERATOR_CURRENTLY_RUNNING) {
zend_error(E_ERROR, "Cannot resume an already running generator");
}
/* Drop the AT_FIRST_YIELD flag */
generator->flags &= ~ZEND_GENERATOR_AT_FIRST_YIELD;
{
/* Backup executor globals */
zend_execute_data *original_execute_data = EG(current_execute_data);
zend_op **original_opline_ptr = EG(opline_ptr);
zend_op_array *original_active_op_array = EG(active_op_array);
zend_array *original_active_symbol_table = EG(active_symbol_table);
zend_object *original_This;
zend_class_entry *original_scope = EG(scope);
zend_class_entry *original_called_scope = EG(called_scope);
zend_vm_stack original_stack = EG(argument_stack);
original_This = Z_OBJ(EG(This));
/* Set executor globals */
EG(current_execute_data) = generator->execute_data;
EG(opline_ptr) = &generator->execute_data->opline;
EG(active_op_array) = generator->execute_data->op_array;
EG(active_symbol_table) = generator->execute_data->symbol_table;
Z_OBJ(EG(This)) = generator->execute_data->object;
EG(scope) = generator->execute_data->scope;
EG(called_scope) = generator->execute_data->called_scope;
EG(argument_stack) = generator->stack;
/* We want the backtrace to look as if the generator function was
* called from whatever method we are current running (e.g. next()).
* The first prev_execute_data contains an additional stack frame,
* which makes the generator function show up in the backtrace and
* makes the arguments available to func_get_args(). So we have to
* set the prev_execute_data of that prev_execute_data :) */
generator->execute_data->prev_execute_data->prev_execute_data = original_execute_data;
/* Resume execution */
generator->flags |= ZEND_GENERATOR_CURRENTLY_RUNNING;
zend_execute_ex(generator->execute_data TSRMLS_CC);
generator->flags &= ~ZEND_GENERATOR_CURRENTLY_RUNNING;
/* Restore executor globals */
EG(current_execute_data) = original_execute_data;
EG(opline_ptr) = original_opline_ptr;
EG(active_op_array) = original_active_op_array;
EG(active_symbol_table) = original_active_symbol_table;
Z_OBJ(EG(This)) = original_This;
EG(scope) = original_scope;
EG(called_scope) = original_called_scope;
EG(argument_stack) = original_stack;
/* If an exception was thrown in the generator we have to internally
* rethrow it in the parent scope. */
if (UNEXPECTED(EG(exception) != NULL)) {
zend_throw_exception_internal(NULL TSRMLS_CC);
}
}
}
/* }}} */
static void zend_generator_ensure_initialized(zend_generator *generator TSRMLS_DC) /* {{{ */
{
if (generator->execute_data && Z_TYPE(generator->value) == IS_UNDEF) {
zend_generator_resume(generator TSRMLS_CC);
generator->flags |= ZEND_GENERATOR_AT_FIRST_YIELD;
}
}
/* }}} */
static void zend_generator_rewind(zend_generator *generator TSRMLS_DC) /* {{{ */
{
zend_generator_ensure_initialized(generator TSRMLS_CC);
if (!(generator->flags & ZEND_GENERATOR_AT_FIRST_YIELD)) {
zend_throw_exception(NULL, "Cannot rewind a generator that was already run", 0 TSRMLS_CC);
}
}
/* }}} */
/* {{{ 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 TSRMLS_CC);
}
/* }}} */
/* {{{ 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 TSRMLS_CC);
RETURN_BOOL(Z_TYPE(generator->value) != IS_UNDEF);
}
/* }}} */
/* {{{ proto mixed Generator::current()
* Get the current value */
ZEND_METHOD(Generator, current)
{
zend_generator *generator;
if (zend_parse_parameters_none() == FAILURE) {
return;
}
generator = (zend_generator *) Z_OBJ_P(getThis());
zend_generator_ensure_initialized(generator TSRMLS_CC);
if (Z_TYPE(generator->value) != IS_UNDEF) {
RETURN_ZVAL_FAST(&generator->value);
}
}
/* }}} */
/* {{{ proto mixed Generator::key()
* Get the current key */
ZEND_METHOD(Generator, key)
{
zend_generator *generator;
if (zend_parse_parameters_none() == FAILURE) {
return;
}
generator = (zend_generator *) Z_OBJ_P(getThis());
zend_generator_ensure_initialized(generator TSRMLS_CC);
if (Z_TYPE(generator->key) != IS_UNDEF) {
RETURN_ZVAL_FAST(&generator->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 TSRMLS_CC);
zend_generator_resume(generator TSRMLS_CC);
}
/* }}} */
/* {{{ proto mixed Generator::send(mixed $value)
* Sends a value to the generator */
ZEND_METHOD(Generator, send)
{
zval *value;
zend_generator *generator;
if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "z", &value) == FAILURE) {
return;
}
generator = (zend_generator *) Z_OBJ_P(getThis());
zend_generator_ensure_initialized(generator TSRMLS_CC);
/* The generator is already closed, thus can't send anything */
if (!generator->execute_data) {
return;
}
/* Put sent value in the target VAR slot, if it is used */
if (generator->send_target) {
if (Z_REFCOUNTED_P(generator->send_target)) Z_DELREF_P(generator->send_target);
ZVAL_COPY(generator->send_target, value);
}
zend_generator_resume(generator TSRMLS_CC);
if (Z_TYPE(generator->value) != IS_UNDEF) {
RETURN_ZVAL_FAST(&generator->value);
}
}
/* }}} */
/* {{{ proto mixed Generator::throw(Exception $exception)
* Throws an exception into the generator */
ZEND_METHOD(Generator, throw)
{
zval *exception, exception_copy;
zend_generator *generator;
if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "z", &exception) == FAILURE) {
return;
}
ZVAL_DUP(&exception_copy, exception);
generator = (zend_generator *) Z_OBJ_P(getThis());
zend_generator_ensure_initialized(generator TSRMLS_CC);
if (generator->execute_data) {
/* Throw the exception in the context of the generator */
zend_execute_data *current_execute_data = EG(current_execute_data);
EG(current_execute_data) = generator->execute_data;
zend_throw_exception_object(&exception_copy TSRMLS_CC);
EG(current_execute_data) = current_execute_data;
zend_generator_resume(generator TSRMLS_CC);
if (Z_TYPE(generator->value) != IS_UNDEF) {
RETURN_ZVAL_FAST(&generator->value);
}
} else {
/* If the generator is already closed throw the exception in the
* current context */
zend_throw_exception_object(&exception_copy TSRMLS_CC);
}
}
/* }}} */
/* {{{ proto void 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 TSRMLS_CC);
}
/* }}} */
/* get_iterator implementation */
static void zend_generator_iterator_dtor(zend_object_iterator *iterator TSRMLS_DC) /* {{{ */
{
zend_generator *generator = (zend_generator*)Z_OBJ(iterator->data);
generator->iterator = NULL;
zval_ptr_dtor(&iterator->data);
zend_iterator_dtor(iterator TSRMLS_CC);
}
/* }}} */
static int zend_generator_iterator_valid(zend_object_iterator *iterator TSRMLS_DC) /* {{{ */
{
zend_generator *generator = (zend_generator*)Z_OBJ(iterator->data);
zend_generator_ensure_initialized(generator TSRMLS_CC);
return Z_TYPE(generator->value) != IS_UNDEF ? SUCCESS : FAILURE;
}
/* }}} */
static zval *zend_generator_iterator_get_data(zend_object_iterator *iterator TSRMLS_DC) /* {{{ */
{
zend_generator *generator = (zend_generator*)Z_OBJ(iterator->data);
zend_generator_ensure_initialized(generator TSRMLS_CC);
return &generator->value;
}
/* }}} */
static void zend_generator_iterator_get_key(zend_object_iterator *iterator, zval *key TSRMLS_DC) /* {{{ */
{
zend_generator *generator = (zend_generator*)Z_OBJ(iterator->data);
zend_generator_ensure_initialized(generator TSRMLS_CC);
if (Z_TYPE(generator->key) != IS_UNDEF) {
ZVAL_ZVAL(key, &generator->key, 1, 0);
} else {
ZVAL_NULL(key);
}
}
/* }}} */
static void zend_generator_iterator_move_forward(zend_object_iterator *iterator TSRMLS_DC) /* {{{ */
{
zend_generator *generator = (zend_generator*)Z_OBJ(iterator->data);
zend_generator_ensure_initialized(generator TSRMLS_CC);
zend_generator_resume(generator TSRMLS_CC);
}
/* }}} */
static void zend_generator_iterator_rewind(zend_object_iterator *iterator TSRMLS_DC) /* {{{ */
{
zend_generator *generator = (zend_generator*)Z_OBJ(iterator->data);
zend_generator_rewind(generator TSRMLS_CC);
}
/* }}} */
static 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
};
zend_object_iterator *zend_generator_get_iterator(zend_class_entry *ce, zval *object, int by_ref TSRMLS_DC) /* {{{ */
{
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 TSRMLS_CC);
return NULL;
}
if (by_ref && !(generator->execute_data->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 TSRMLS_CC);
return NULL;
}
iterator = generator->iterator = emalloc(sizeof(zend_object_iterator));
zend_iterator_init(iterator TSRMLS_CC);
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, __wakeup, arginfo_generator_void, ZEND_ACC_PUBLIC)
ZEND_FE_END
};
void zend_register_generator_ce(TSRMLS_D) /* {{{ */
{
zend_class_entry ce;
INIT_CLASS_ENTRY(ce, "Generator", generator_functions);
zend_ce_generator = zend_register_internal_class(&ce TSRMLS_CC);
zend_ce_generator->ce_flags |= ZEND_ACC_FINAL_CLASS;
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 TSRMLS_CC, 1, zend_ce_iterator);
zend_ce_generator->get_iterator = zend_generator_get_iterator;
zend_ce_generator->iterator_funcs.funcs = &zend_generator_iterator_functions;
memcpy(&zend_generator_handlers, zend_get_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.clone_obj = NULL;
zend_generator_handlers.get_constructor = zend_generator_get_constructor;
}
/* }}} */
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* indent-tabs-mode: t
* End:
*/