From 6bf0a5cb5034a7e684dcc3500e841785237ce2dd Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 19:32:43 +0200 Subject: Adding upstream version 1:115.7.0. Signed-off-by: Daniel Baumann --- layout/style/Rule.cpp | 129 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 129 insertions(+) create mode 100644 layout/style/Rule.cpp (limited to 'layout/style/Rule.cpp') diff --git a/layout/style/Rule.cpp b/layout/style/Rule.cpp new file mode 100644 index 0000000000..a107dc3f01 --- /dev/null +++ b/layout/style/Rule.cpp @@ -0,0 +1,129 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/* base class for all rule types in a CSS style sheet */ + +#include "Rule.h" + +#include "mozilla/css/GroupRule.h" +#include "mozilla/dom/CSSImportRule.h" +#include "mozilla/dom/DocumentOrShadowRoot.h" +#include "nsCCUncollectableMarker.h" +#include "mozilla/dom/Document.h" +#include "mozilla/HoldDropJSObjects.h" +#include "nsWrapperCacheInlines.h" +#include "mozilla/ServoBindings.h" + +using namespace mozilla; +using namespace mozilla::dom; + +namespace mozilla::css { + +NS_IMPL_CYCLE_COLLECTING_ADDREF(Rule) +NS_IMPL_CYCLE_COLLECTING_RELEASE(Rule) + +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(Rule) + NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY + NS_INTERFACE_MAP_ENTRY(nsISupports) +NS_INTERFACE_MAP_END + +NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_0(Rule) + +bool Rule::IsCCLeaf() const { return !PreservingWrapper(); } + +bool Rule::IsKnownLive() const { + if (HasKnownLiveWrapper()) { + return true; + } + + StyleSheet* sheet = GetStyleSheet(); + if (!sheet) { + return false; + } + + Document* doc = sheet->GetKeptAliveByDocument(); + return doc && + nsCCUncollectableMarker::InGeneration(doc->GetMarkedCCGeneration()); +} + +void Rule::UnlinkDeclarationWrapper(nsWrapperCache& aDecl) { + // We have to be a bit careful here. We have two separate nsWrapperCache + // instances, aDecl and this, that both correspond to the same CC participant: + // this. If we just used ReleaseWrapper() on one of them, that would + // unpreserve that one wrapper, then trace us with a tracer that clears JS + // things, and we would clear the wrapper on the cache that has not + // unpreserved the wrapper yet. That would violate the invariant that the + // cache keeps caching the wrapper until the wrapper dies. + // + // So we reimplement a modified version of nsWrapperCache::ReleaseWrapper here + // that unpreserves both wrappers before doing any clearing. + bool needDrop = PreservingWrapper() || aDecl.PreservingWrapper(); + SetPreservingWrapper(false); + aDecl.SetPreservingWrapper(false); + if (needDrop) { + DropJSObjects(this); + } +} + +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(Rule) + return tmp->IsCCLeaf() || tmp->IsKnownLive(); +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_END + +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_BEGIN(Rule) + // Please see documentation for nsCycleCollectionParticipant::CanSkip* for why + // we need to check HasNothingToTrace here but not in the other two CanSkip + // methods. + return tmp->IsCCLeaf() || (tmp->IsKnownLive() && tmp->HasNothingToTrace(tmp)); +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END + +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(Rule) + return tmp->IsCCLeaf() || tmp->IsKnownLive(); +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_END + +/* virtual */ +void Rule::DropSheetReference() { mSheet = nullptr; } + +void Rule::SetCssText(const nsACString& aCssText) { + // We used to throw for some rule types, but not all. Specifically, we did + // not throw for StyleRule. Let's just always not throw. +} + +Rule* Rule::GetParentRule() const { return mParentRule; } + +#ifdef DEBUG +void Rule::AssertParentRuleType() { + // Would be nice to check that this->Type() is KEYFRAME_RULE when + // mParentRule->Tye() is KEYFRAMES_RULE, but we can't call + // this->Type() here since it's virtual. + if (mParentRule) { + auto type = mParentRule->Type(); + MOZ_ASSERT(type == StyleCssRuleType::Media || + type == StyleCssRuleType::Document || + type == StyleCssRuleType::Supports || + type == StyleCssRuleType::Keyframes || + type == StyleCssRuleType::LayerBlock || + type == StyleCssRuleType::Container); + } +} +#endif + +bool Rule::IsReadOnly() const { + MOZ_ASSERT(!mSheet || !mParentRule || + mSheet->IsReadOnly() == mParentRule->IsReadOnly(), + "a parent rule should be read only iff the owning sheet is " + "read only"); + return mSheet && mSheet->IsReadOnly(); +} + +bool Rule::IsIncompleteImportRule() const { + if (Type() != StyleCssRuleType::Import) { + return false; + } + auto* sheet = static_cast(this)->GetStyleSheet(); + return !sheet || !sheet->IsComplete(); +} + +} // namespace mozilla::css -- cgit v1.2.3