cacced7e50
Currently we rely on some undefined behavior when Object->cast_to() gets called with a Null pointer. This used to work fine with GCC < 6 but newer versions of GCC remove all codepaths in which the this pointer is Null. However, the non-static cast_to() was supposed to be null safe. This patch makes cast_to() Null safe and removes the now redundant Null checks where they existed. It is explained in this article: https://www.viva64.com/en/b/0226/
168 lines
4.8 KiB
C++
168 lines
4.8 KiB
C++
/*************************************************************************/
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/* reference.cpp */
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/*************************************************************************/
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/* This file is part of: */
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/* GODOT ENGINE */
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/* http://www.godotengine.org */
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/*************************************************************************/
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/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur. */
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/* Copyright (c) 2014-2017 Godot Engine contributors (cf. AUTHORS.md) */
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/* */
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/* Permission is hereby granted, free of charge, to any person obtaining */
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/* a copy of this software and associated documentation files (the */
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/* "Software"), to deal in the Software without restriction, including */
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/* without limitation the rights to use, copy, modify, merge, publish, */
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/* distribute, sublicense, and/or sell copies of the Software, and to */
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/* permit persons to whom the Software is furnished to do so, subject to */
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/* the following conditions: */
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/* */
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/* The above copyright notice and this permission notice shall be */
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/* included in all copies or substantial portions of the Software. */
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/* */
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/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
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/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
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/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
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/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
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/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
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/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
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/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
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/*************************************************************************/
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#include "reference.h"
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#include "script_language.h"
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bool Reference::init_ref() {
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if (refcount.ref()) {
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// this may fail in the scenario of two threads assigning the pointer for the FIRST TIME
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// at the same time, which is never likely to happen (would be crazy to do)
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// so don't do it.
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if (refcount_init.get() > 0) {
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refcount_init.unref();
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refcount.unref(); // first referencing is already 1, so compensate for the ref above
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}
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return true;
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} else {
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return false;
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}
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}
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void Reference::_bind_methods() {
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ClassDB::bind_method(D_METHOD("init_ref"), &Reference::init_ref);
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ClassDB::bind_method(D_METHOD("reference"), &Reference::reference);
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ClassDB::bind_method(D_METHOD("unreference"), &Reference::unreference);
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}
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int Reference::reference_get_count() const {
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return refcount.get();
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}
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void Reference::reference() {
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refcount.ref();
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if (get_script_instance()) {
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get_script_instance()->refcount_incremented();
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}
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}
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bool Reference::unreference() {
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bool die = refcount.unref();
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if (get_script_instance()) {
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bool script_ret = get_script_instance()->refcount_decremented();
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die = die && script_ret;
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}
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return die;
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}
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Reference::Reference() {
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refcount.init();
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refcount_init.init();
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}
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Reference::~Reference() {
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}
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Variant WeakRef::get_ref() const {
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if (ref == 0)
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return Variant();
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Object *obj = ObjectDB::get_instance(ref);
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if (!obj)
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return Variant();
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Reference *r = cast_to<Reference>(obj);
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if (r) {
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return REF(r);
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}
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return obj;
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}
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void WeakRef::set_obj(Object *p_object) {
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ref = p_object ? p_object->get_instance_id() : 0;
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}
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void WeakRef::set_ref(const REF &p_ref) {
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ref = p_ref.is_valid() ? p_ref->get_instance_id() : 0;
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}
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WeakRef::WeakRef() {
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ref = 0;
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}
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void WeakRef::_bind_methods() {
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ClassDB::bind_method(D_METHOD("get_ref"), &WeakRef::get_ref);
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}
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#if 0
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Reference * RefBase::get_reference_from_ref(const RefBase &p_base) {
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return p_base.get_reference();
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}
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void RefBase::ref_inc(Reference *p_reference) {
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p_reference->refcount.ref();
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}
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bool RefBase::ref_dec(Reference *p_reference) {
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bool ref = p_reference->refcount.unref();
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return ref;
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}
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Reference *RefBase::first_ref(Reference *p_reference) {
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if (p_reference->refcount.ref()) {
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// this may fail in the scenario of two threads assigning the pointer for the FIRST TIME
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// at the same time, which is never likely to happen (would be crazy to do)
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// so don't do it.
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if (p_reference->refcount_init.get()>0) {
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p_reference->refcount_init.unref();
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p_reference->refcount.unref(); // first referencing is already 1, so compensate for the ref above
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}
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return p_reference;
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} else {
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return 0;
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}
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}
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char * RefBase::get_refptr_data(const RefPtr &p_refptr) const {
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return p_refptr.data;
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}
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#endif
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