zend_objects.c

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/*
   +----------------------------------------------------------------------+
   | Zend Engine                                                          |
   +----------------------------------------------------------------------+
   | Copyright (c) Zend Technologies Ltd. (http://www.zend.com)           |
   +----------------------------------------------------------------------+
   | This source file is subject to version 2.00 of the Zend license,     |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | http://www.zend.com/license/2_00.txt.                                |
   | If you did not receive a copy of the Zend license and are unable to  |
   | obtain it through the world-wide-web, please send a note to          |
   | license@zend.com so we can mail you a copy immediately.              |
   +----------------------------------------------------------------------+
   | Authors: Andi Gutmans <andi@php.net>                                 |
   |          Zeev Suraski <zeev@php.net>                                 |
   |          Dmitry Stogov <dmitry@php.net>                              |
   +----------------------------------------------------------------------+
*/
 
#include "zend.h"
#include "zend_globals.h"
#include "zend_variables.h"
#include "zend_API.h"
#include "zend_interfaces.h"
#include "zend_exceptions.h"
#include "zend_weakrefs.h"
#include "zend_lazy_objects.h"
 
static zend_always_inline void _zend_object_std_init(zend_object *object, zend_class_entry *ce)
{
    GC_SET_REFCOUNT(object, 1);
    GC_TYPE_INFO(object) = GC_OBJECT;
    object->ce = ce;
    object->extra_flags = 0;
    object->handlers = ce->default_object_handlers;
    object->properties = NULL;
    zend_objects_store_put(object);
    if (UNEXPECTED(ce->ce_flags & ZEND_ACC_USE_GUARDS)) {
        zval *guard_value = object->properties_table + object->ce->default_properties_count;
        ZVAL_UNDEF(guard_value);
        Z_GUARD_P(guard_value) = 0;
    }
}
 
ZEND_API void ZEND_FASTCALL zend_object_std_init(zend_object *object, zend_class_entry *ce)
{
    _zend_object_std_init(object, ce);
}
 
void zend_object_dtor_dynamic_properties(zend_object *object)
{
    if (object->properties) {
        if (EXPECTED(!(GC_FLAGS(object->properties) & IS_ARRAY_IMMUTABLE))) {
            if (EXPECTED(GC_DELREF(object->properties) == 0)
                    && EXPECTED(GC_TYPE(object->properties) != IS_NULL)) {
                zend_array_destroy(object->properties);
            }
        }
    }
}
 
void zend_object_dtor_property(zend_object *object, zval *p)
{
    if (Z_REFCOUNTED_P(p)) {
        if (UNEXPECTED(Z_ISREF_P(p)) &&
                (ZEND_DEBUG || ZEND_REF_HAS_TYPE_SOURCES(Z_REF_P(p)))) {
            zend_property_info *prop_info = zend_get_property_info_for_slot_self(object, p);
            if (ZEND_TYPE_IS_SET(prop_info->type)) {
                ZEND_REF_DEL_TYPE_SOURCE(Z_REF_P(p), prop_info);
            }
        }
        i_zval_ptr_dtor(p);
    }
}
 
ZEND_API void zend_object_std_dtor(zend_object *object)
{
    zval *p, *end;
 
    if (UNEXPECTED(GC_FLAGS(object) & IS_OBJ_WEAKLY_REFERENCED)) {
        zend_weakrefs_notify(object);
    }
 
    if (UNEXPECTED(zend_object_is_lazy(object))) {
        zend_lazy_object_del_info(object);
    }
 
    zend_object_dtor_dynamic_properties(object);
 
    p = object->properties_table;
    if (EXPECTED(object->ce->default_properties_count)) {
        end = p + object->ce->default_properties_count;
        do {
            zend_object_dtor_property(object, p);
            p++;
        } while (p != end);
    }
 
    if (UNEXPECTED(object->ce->ce_flags & ZEND_ACC_USE_GUARDS)) {
        if (EXPECTED(Z_TYPE_P(p) == IS_STRING)) {
            zval_ptr_dtor_str(p);
        } else if (Z_TYPE_P(p) == IS_ARRAY) {
            HashTable *guards;
 
            guards = Z_ARRVAL_P(p);
            ZEND_ASSERT(guards != NULL);
            zend_hash_destroy(guards);
            FREE_HASHTABLE(guards);
        }
    }
}
 
ZEND_API void zend_objects_destroy_object(zend_object *object)
{
    zend_function *destructor = object->ce->destructor;
 
    if (destructor) {
        if (UNEXPECTED(zend_object_is_lazy(object))) {
            return;
        }
 
        zend_object *old_exception;
        const zend_op *old_opline_before_exception;
 
        if (destructor->op_array.fn_flags & (ZEND_ACC_PRIVATE|ZEND_ACC_PROTECTED)) {
            if (destructor->op_array.fn_flags & ZEND_ACC_PRIVATE) {
                /* Ensure that if we're calling a private function, we're allowed to do so.
                 */
                if (EG(current_execute_data)) {
                    zend_class_entry *scope = zend_get_executed_scope();
 
                    if (object->ce != scope) {
                        zend_throw_error(NULL,
                            "Call to private %s::__destruct() from %s%s",
                            ZSTR_VAL(object->ce->name),
                            scope ? "scope " : "global scope",
                            scope ? ZSTR_VAL(scope->name) : ""
                        );
                        return;
                    }
                } else {
                    zend_error(E_WARNING,
                        "Call to private %s::__destruct() from global scope during shutdown ignored",
                        ZSTR_VAL(object->ce->name));
                    return;
                }
            } else {
                /* Ensure that if we're calling a protected function, we're allowed to do so.
                 */
                if (EG(current_execute_data)) {
                    zend_class_entry *scope = zend_get_executed_scope();
 
                    if (!zend_check_protected(zend_get_function_root_class(destructor), scope)) {
                        zend_throw_error(NULL,
                            "Call to protected %s::__destruct() from %s%s",
                            ZSTR_VAL(object->ce->name),
                            scope ? "scope " : "global scope",
                            scope ? ZSTR_VAL(scope->name) : ""
                        );
                        return;
                    }
                } else {
                    zend_error(E_WARNING,
                        "Call to protected %s::__destruct() from global scope during shutdown ignored",
                        ZSTR_VAL(object->ce->name));
                    return;
                }
            }
        }
 
        GC_ADDREF(object);
 
        /* Make sure that destructors are protected from previously thrown exceptions.
         * For example, if an exception was thrown in a function and when the function's
         * local variable destruction results in a destructor being called.
         */
        old_exception = NULL;
        if (EG(exception)) {
            if (EG(exception) == object) {
                zend_error_noreturn(E_CORE_ERROR, "Attempt to destruct pending exception");
            } else {
                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));
                }
                old_exception = EG(exception);
                old_opline_before_exception = EG(opline_before_exception);
                EG(exception) = NULL;
            }
        }
 
        zend_call_known_instance_method_with_0_params(destructor, object, NULL);
 
        if (old_exception) {
            EG(opline_before_exception) = old_opline_before_exception;
            if (EG(exception)) {
                zend_exception_set_previous(EG(exception), old_exception);
            } else {
                EG(exception) = old_exception;
            }
        }
        OBJ_RELEASE(object);
    }
}
 
ZEND_API zend_object* ZEND_FASTCALL zend_objects_new(zend_class_entry *ce)
{
    zend_object *object = emalloc(sizeof(zend_object) + zend_object_properties_size(ce));
 
    _zend_object_std_init(object, ce);
    return object;
}
 
ZEND_API void ZEND_FASTCALL zend_objects_clone_members(zend_object *new_object, zend_object *old_object)
{
    bool has_clone_method = old_object->ce->clone != NULL;
 
    if (old_object->ce->default_properties_count) {
        zval *src = old_object->properties_table;
        zval *dst = new_object->properties_table;
        zval *end = src + old_object->ce->default_properties_count;
 
        do {
            i_zval_ptr_dtor(dst);
            ZVAL_COPY_VALUE_PROP(dst, src);
            zval_add_ref(dst);
            if (has_clone_method) {
                /* Unconditionally add the IS_PROP_REINITABLE flag to avoid a potential cache miss of property_info */
                Z_PROP_FLAG_P(dst) |= IS_PROP_REINITABLE;
            }
 
            if (UNEXPECTED(Z_ISREF_P(dst)) &&
                    (ZEND_DEBUG || ZEND_REF_HAS_TYPE_SOURCES(Z_REF_P(dst)))) {
                zend_property_info *prop_info = zend_get_property_info_for_slot_self(new_object, dst);
                if (ZEND_TYPE_IS_SET(prop_info->type)) {
                    ZEND_REF_ADD_TYPE_SOURCE(Z_REF_P(dst), prop_info);
                }
            }
            src++;
            dst++;
        } while (src != end);
    } else if (old_object->properties && !has_clone_method) {
        /* fast copy */
        if (EXPECTED(old_object->handlers == &std_object_handlers)) {
            if (EXPECTED(!(GC_FLAGS(old_object->properties) & IS_ARRAY_IMMUTABLE))) {
                GC_ADDREF(old_object->properties);
            }
            new_object->properties = old_object->properties;
            return;
        }
    }
 
    if (old_object->properties &&
        EXPECTED(zend_hash_num_elements(old_object->properties))) {
        zval *prop, new_prop;
        zend_ulong num_key;
        zend_string *key;
 
        if (!new_object->properties) {
            new_object->properties = zend_new_array(zend_hash_num_elements(old_object->properties));
            zend_hash_real_init_mixed(new_object->properties);
        } else {
            zend_hash_extend(new_object->properties, new_object->properties->nNumUsed + zend_hash_num_elements(old_object->properties), 0);
        }
 
        HT_FLAGS(new_object->properties) |=
            HT_FLAGS(old_object->properties) & HASH_FLAG_HAS_EMPTY_IND;
 
        ZEND_HASH_MAP_FOREACH_KEY_VAL(old_object->properties, num_key, key, prop) {
            if (Z_TYPE_P(prop) == IS_INDIRECT) {
                ZVAL_INDIRECT(&new_prop, new_object->properties_table + (Z_INDIRECT_P(prop) - old_object->properties_table));
            } else {
                ZVAL_COPY_VALUE(&new_prop, prop);
                zval_add_ref(&new_prop);
            }
            if (has_clone_method) {
                /* Unconditionally add the IS_PROP_REINITABLE flag to avoid a potential cache miss of property_info */
                Z_PROP_FLAG_P(&new_prop) |= IS_PROP_REINITABLE;
            }
            if (EXPECTED(key)) {
                _zend_hash_append(new_object->properties, key, &new_prop);
            } else {
                zend_hash_index_add_new(new_object->properties, num_key, &new_prop);
            }
        } ZEND_HASH_FOREACH_END();
    }
 
    if (has_clone_method) {
        GC_ADDREF(new_object);
        zend_call_known_instance_method_with_0_params(new_object->ce->clone, new_object, NULL);
 
        if (ZEND_CLASS_HAS_READONLY_PROPS(new_object->ce)) {
            for (uint32_t i = 0; i < new_object->ce->default_properties_count; i++) {
                zval* prop = OBJ_PROP_NUM(new_object, i);
                /* Unconditionally remove the IS_PROP_REINITABLE flag to avoid a potential cache miss of property_info */
                Z_PROP_FLAG_P(prop) &= ~IS_PROP_REINITABLE;
            }
        }
 
        OBJ_RELEASE(new_object);
    }
}
 
ZEND_API zend_object *zend_objects_clone_obj(zend_object *old_object)
{
    zend_object *new_object;
 
    if (UNEXPECTED(zend_object_is_lazy(old_object))) {
        return zend_lazy_object_clone(old_object);
    }
 
    /* assume that create isn't overwritten, so when clone depends on the
     * overwritten one then it must itself be overwritten */
    new_object = zend_objects_new(old_object->ce);
 
    /* zend_objects_clone_members() expect the properties to be initialized. */
    if (new_object->ce->default_properties_count) {
        zval *p = new_object->properties_table;
        zval *end = p + new_object->ce->default_properties_count;
        do {
            ZVAL_UNDEF(p);
            p++;
        } while (p != end);
    }
 
    zend_objects_clone_members(new_object, old_object);
 
    return new_object;
}