/* +----------------------------------------------------------------------+ | Zend Engine | +----------------------------------------------------------------------+ | Copyright (c) 1998-2015 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 | +----------------------------------------------------------------------+ */ /* $Id$ */ #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); 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) { Z_DELREF_PP(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: { 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 */ { void **ptr = generator->stack->top - 1; void **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) { zval_ptr_dtor(&execute_data->call->object); } execute_data->call--; } } /* }}} */ 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)) { generator->execute_data = NULL; 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; 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); } } } /* 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_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; } /* }}} */ static void 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_PP(var); zend_hash_quick_update(target, key->arKey, key->nKeyLength, key->h, var, sizeof(zval *), NULL); } /* }}} */ /* 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; (*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, (apply_func_args_t) 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, 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 in the target VAR slot, if it is used */ if (generator->send_target) { Z_DELREF_PP(generator->send_target); Z_ADDREF_P(value); *generator->send_target = value; } 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); 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 (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) /* {{{ */ { zend_generator_iterator *iter = (zend_generator_iterator *) iterator; zend_objects_store_del_ref_by_handle(iter->handle TSRMLS_CC); } /* }}} */ 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. */ iterator->handle = Z_OBJ_HANDLE_P(object); zend_objects_store_add_ref_by_handle(iterator->handle TSRMLS_CC); 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: */