diff options
Diffstat (limited to 'Zend/zend_generators.c')
| -rw-r--r-- | Zend/zend_generators.c | 717 |
1 files changed, 717 insertions, 0 deletions
diff --git a/Zend/zend_generators.c b/Zend/zend_generators.c new file mode 100644 index 0000000000..1a805bbd6d --- /dev/null +++ b/Zend/zend_generators.c @@ -0,0 +1,717 @@ +/* + +----------------------------------------------------------------------+ + | Zend Engine | + +----------------------------------------------------------------------+ + | Copyright (c) 1998-2013 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_value zend_generator_create(zend_class_entry *class_type TSRMLS_DC); + +ZEND_API void zend_generator_close(zend_generator *generator, zend_bool finished_execution TSRMLS_DC) /* {{{ */ +{ + if (generator->value) { + zval_ptr_dtor(&generator->value); + generator->value = NULL; + } + + if (generator->key) { + zval_ptr_dtor(&generator->key); + generator->key = NULL; + } + + 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); + } else { + zend_clean_and_cache_symbol_table(execute_data->symbol_table TSRMLS_CC); + } + + if (execute_data->current_this) { + zval_ptr_dtor(&execute_data->current_this); + } + + /* 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; + } + + /* If the generator is closed before it can finish execution (reach + * a return statement) we have to free loop variables manually, as + * we don't know whether the SWITCH_FREE / FREE opcodes have run */ + if (!finished_execution) { + /* -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: + { + temp_variable *var = EX_TMP_VAR(execute_data, brk_opline->op1.var); + zval_ptr_dtor(&var->var.ptr); + } + break; + case ZEND_FREE: + { + temp_variable *var = EX_TMP_VAR(execute_data, brk_opline->op1.var); + zval_dtor(&var->tmp_var); + } + break; + } + } + } + } + + /* Clear any backed up stack arguments */ + if (generator->stack != EG(argument_stack)) { + void **ptr = generator->stack->top - 1; + void **end = zend_vm_stack_frame_base(execute_data); + + /* If the top stack element is the argument count, skip it */ + if (execute_data->function_state.arguments) { + ptr--; + } + + for (; ptr >= end; --ptr) { + zval_ptr_dtor((zval**) ptr); + } + } + + while (execute_data->call >= execute_data->call_slots) { + if (execute_data->call->object) { + zval_ptr_dtor(&execute_data->call->object); + } + execute_data->call--; + } + + /* 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; + void **arguments = prev_execute_data->function_state.arguments; + + if (arguments) { + int arguments_count = (int) (zend_uintptr_t) *arguments; + zval **arguments_start = (zval **) (arguments - arguments_count); + int i; + + for (i = 0; i < arguments_count; ++i) { + zval_ptr_dtor(arguments_start + i); + } + } + } + + /* 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); + if (generator->stack == EG(argument_stack)) { + /* abnormal exit for running generator */ + EG(argument_stack) = NULL; + } + generator->execute_data = NULL; + } +} +/* }}} */ + +static void zend_generator_dtor_storage(zend_generator *generator, zend_object_handle handle TSRMLS_DC) /* {{{ */ +{ + 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_generator *generator TSRMLS_DC) /* {{{ */ +{ + zend_generator_close(generator, 0 TSRMLS_CC); + + zend_object_std_dtor(&generator->std TSRMLS_CC); + efree(generator); +} +/* }}} */ + +static zend_object_value zend_generator_create(zend_class_entry *class_type TSRMLS_DC) /* {{{ */ +{ + zend_generator *generator; + zend_object_value object; + + 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); + + object.handle = zend_objects_store_put(generator, + (zend_objects_store_dtor_t) zend_generator_dtor_storage, + (zend_objects_free_object_storage_t) zend_generator_free_storage, + NULL TSRMLS_CC + ); + object.handlers = &zend_generator_handlers; + + return object; +} +/* }}} */ + +/* Requires globals EG(scope), EG(current_scope), EG(This), + * EG(active_symbol_table) and EG(current_execute_data). */ +ZEND_API zval *zend_generator_create_zval(zend_op_array *op_array TSRMLS_DC) /* {{{ */ +{ + zval *return_value; + zend_generator *generator; + zend_execute_data *current_execute_data; + zend_op **opline_ptr; + HashTable *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; + function_add_ref((zend_function *) op_array_copy); + 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, 0 TSRMLS_CC); + EG(active_symbol_table) = current_symbol_table; + EG(current_execute_data) = current_execute_data; + EG(opline_ptr) = opline_ptr; + + ALLOC_INIT_ZVAL(return_value); + object_init_ex(return_value, zend_ce_generator); + + if (EG(This)) { + Z_ADDREF_P(EG(This)); + } + + /* Back up executor globals. */ + execute_data->current_scope = EG(scope); + execute_data->current_called_scope = EG(called_scope); + execute_data->symbol_table = EG(active_symbol_table); + execute_data->current_this = EG(This); + + /* Save execution context in generator object. */ + generator = (zend_generator *) zend_object_store_get_object(return_value TSRMLS_CC); + generator->execute_data = execute_data; + generator->stack = EG(argument_stack); + EG(argument_stack) = current_stack; + + return return_value; +} +/* }}} */ + +static zend_function *zend_generator_get_constructor(zval *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 */ + zval **original_return_value_ptr_ptr = EG(return_value_ptr_ptr); + 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); + HashTable *original_active_symbol_table = EG(active_symbol_table); + zval *original_This = EG(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); + + /* We (mis)use the return_value_ptr_ptr to provide the generator object + * to the executor, so YIELD will be able to set the yielded value */ + EG(return_value_ptr_ptr) = (zval **) generator; + + /* 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; + EG(This) = generator->execute_data->current_this; + EG(scope) = generator->execute_data->current_scope; + EG(called_scope) = generator->execute_data->current_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(return_value_ptr_ptr) = original_return_value_ptr_ptr; + 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; + 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 && !generator->value) { + 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 *) zend_object_store_get_object(getThis() TSRMLS_CC); + + 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 *) zend_object_store_get_object(getThis() TSRMLS_CC); + + zend_generator_ensure_initialized(generator TSRMLS_CC); + + RETURN_BOOL(generator->value != NULL); +} +/* }}} */ + +/* {{{ 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 *) zend_object_store_get_object(getThis() TSRMLS_CC); + + zend_generator_ensure_initialized(generator TSRMLS_CC); + + if (generator->value) { + RETURN_ZVAL(generator->value, 1, 0); + } +} +/* }}} */ + +/* {{{ 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 *) zend_object_store_get_object(getThis() TSRMLS_CC); + + zend_generator_ensure_initialized(generator TSRMLS_CC); + + if (generator->key) { + RETURN_ZVAL(generator->key, 1, 0); + } +} +/* }}} */ + +/* {{{ proto void Generator::next() + * Advances the generator */ +ZEND_METHOD(Generator, next) +{ + zend_generator *generator; + + if (zend_parse_parameters_none() == FAILURE) { + return; + } + + generator = (zend_generator *) zend_object_store_get_object(getThis() TSRMLS_CC); + + 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 *) zend_object_store_get_object(getThis() TSRMLS_CC); + + 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 into the TMP_VAR slot */ + MAKE_COPY_ZVAL(&value, &generator->send_target->tmp_var); + + zend_generator_resume(generator TSRMLS_CC); + + if (generator->value) { + RETURN_ZVAL(generator->value, 1, 0); + } +} +/* }}} */ + +/* {{{ 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; + } + + ALLOC_ZVAL(exception_copy); + MAKE_COPY_ZVAL(&exception, exception_copy); + + generator = (zend_generator *) zend_object_store_get_object(getThis() 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 (generator->value) { + RETURN_ZVAL(generator->value, 1, 0); + } + } 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) /* {{{ */ +{ + zval *object = ((zend_generator_iterator *) iterator)->object; + + zval_ptr_dtor(&object); +} +/* }}} */ + +static int zend_generator_iterator_valid(zend_object_iterator *iterator TSRMLS_DC) /* {{{ */ +{ + zend_generator *generator = (zend_generator *) iterator->data; + + zend_generator_ensure_initialized(generator TSRMLS_CC); + + return generator->value != NULL ? SUCCESS : FAILURE; +} +/* }}} */ + +static void zend_generator_iterator_get_data(zend_object_iterator *iterator, zval ***data TSRMLS_DC) /* {{{ */ +{ + zend_generator *generator = (zend_generator *) iterator->data; + + zend_generator_ensure_initialized(generator TSRMLS_CC); + + if (generator->value) { + *data = &generator->value; + } else { + *data = NULL; + } +} +/* }}} */ + +static void zend_generator_iterator_get_key(zend_object_iterator *iterator, zval *key TSRMLS_DC) /* {{{ */ +{ + zend_generator *generator = (zend_generator *) iterator->data; + + zend_generator_ensure_initialized(generator TSRMLS_CC); + + if (generator->key) { + 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 *) 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 *) 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_generator_iterator *iterator; + zend_generator *generator; + + generator = (zend_generator *) zend_object_store_get_object(object TSRMLS_CC); + + 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; + iterator->intern.funcs = &zend_generator_iterator_functions; + iterator->intern.data = (void *) generator; + + /* We have to keep a reference to the generator object zval around, + * otherwise the generator may be destroyed during iteration. */ + Z_ADDREF_P(object); + iterator->object = object; + + return (zend_object_iterator *) 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.get_constructor = zend_generator_get_constructor; + zend_generator_handlers.clone_obj = NULL; +} +/* }}} */ + +/* + * Local variables: + * tab-width: 4 + * c-basic-offset: 4 + * indent-tabs-mode: t + * End: + */ |