blob: 4b0f783bd961b6af0b2cc60abe79ee07c372c130 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
/* -*- 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::Style ||
type == StyleCssRuleType::Document ||
type == StyleCssRuleType::Supports ||
type == StyleCssRuleType::Keyframes ||
type == StyleCssRuleType::LayerBlock ||
type == StyleCssRuleType::Container ||
type == StyleCssRuleType::Scope ||
type == StyleCssRuleType::StartingStyle);
}
}
#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<const dom::CSSImportRule*>(this)->GetStyleSheet();
return !sheet || !sheet->IsComplete();
}
} // namespace mozilla::css
|
