commit	079ec251eb04c779bf10beb361ba7ea4bac9f84d	[log] [tgz]
author	rniwa@webkit.org <rniwa@webkit.org@268f45cc-cd09-0410-ab3c-d52691b4dbfc>	Sat Aug 17 00:41:04 2019 +0000
committer	rniwa@webkit.org <rniwa@webkit.org@268f45cc-cd09-0410-ab3c-d52691b4dbfc>	Sat Aug 17 00:41:04 2019 +0000
tree	ce42a825bb1bdb26dbdd546e723cd8bc3fcbaa49
parent	658142aebe9763cebe516eeef359aacc20e402c7 [diff]

Don't use union to store NodeRareData* and RenderObject*
https://bugs.webkit.org/show_bug.cgi?id=200744

Reviewed by Antti Koivisto.

Source/WebCore:

This patch undoes unioning of NodeRareData* and RenderObject* in Node introduced in r133372 in order
to eliminate any possibility of type confusion bugs. Instead of re-introducing the global map, which
is known to be slow, this patch simply adds an extra pointer for NodeRareData: Node::m_rareData.

To compensate for the increased memory usage due to a new pointer type in Node, this patch also packs
the style related flags in ElementRareData, which is the most common reason for which ElementRareData
is created, into RenderObject* pointer using CompactPointerTuple as Node::m_rendererWithStyleFlags.

Unfortunately, there are 9 style related flags and they won't all fit into the single byte provided
by CompactPointerTuple. Luckily, this patch also eliminates the need for HasRareDataFlag as m_rareData
knows whether a node has rare data or not so we re-use that bitflag space for the extra one flag.

No new tests since there should be no observable behavioral change from this.

* cssjit/SelectorCompiler.cpp:
(WebCore::SelectorCompiler::SelectorCodeGenerator::generateElementIsNthChild): Check the nullity of
m_rareData directly instead of checking HasRareDataFlag, which has been removed.
* dom/Element.cpp:
(WebCore::Element::setStyleAffectedByEmpty): Deleted.
(WebCore::Element::setStyleAffectedByFocusWithin): Deleted.
(WebCore::Element::setStyleAffectedByActive): Deleted.
(WebCore::Element::setChildrenAffectedByDrag): Deleted.
(WebCore::Element::setChildrenAffectedByForwardPositionalRules): Deleted.
(WebCore::Element::setDescendantsAffectedByForwardPositionalRules): Deleted.
(WebCore::Element::setChildrenAffectedByBackwardPositionalRules): Deleted.
(WebCore::Element::setDescendantsAffectedByBackwardPositionalRules): Deleted.
(WebCore::Element::setChildrenAffectedByPropertyBasedBackwardPositionalRules): Deleted.
(WebCore::Element::hasFlagsSetDuringStylingOfChildren const):
(WebCore::Element::resetStyleRelations): Clear the flags in m_rendererWithStyleFlags and m_nodeFlags.
(WebCore::Element::rareDataStyleAffectedByEmpty const): Deleted.
(WebCore::Element::rareDataStyleAffectedByFocusWithin const): Deleted.
(WebCore::Element::rareDataStyleAffectedByActive const): Deleted.
(WebCore::Element::rareDataChildrenAffectedByDrag const): Deleted.
(WebCore::Element::rareDataChildrenAffectedByForwardPositionalRules const): Deleted.
(WebCore::Element::rareDataDescendantsAffectedByForwardPositionalRules const): Deleted.
(WebCore::Element::rareDataChildrenAffectedByBackwardPositionalRules const): Deleted.
(WebCore::Element::rareDataDescendantsAffectedByBackwardPositionalRules const): Deleted.
(WebCore::Element::rareDataChildrenAffectedByPropertyBasedBackwardPositionalRules const): Deleted.
* dom/Element.h:
(WebCore::Element::styleAffectedByActive const): Now uses m_rendererWithStyleFlags.
(WebCore::Element::styleAffectedByEmpty const): Ditto.
(WebCore::Element::styleAffectedByFocusWithin const): Now uses m_nodeFlags.
(WebCore::Element::childrenAffectedByDrag const): Now uses m_rendererWithStyleFlags.
(WebCore::Element::childrenAffectedByForwardPositionalRules const): Ditto.
(WebCore::Element::descendantsAffectedByForwardPositionalRules const): Ditto.
(WebCore::Element::childrenAffectedByBackwardPositionalRules const): Ditto.
(WebCore::Element::descendantsAffectedByBackwardPositionalRules const): Ditto.
(WebCore::Element::childrenAffectedByPropertyBasedBackwardPositionalRules const): Ditto.
(WebCore::Element::setStyleAffectedByEmpty): Now stores into m_rendererWithStyleFlags.
(WebCore::Element::setStyleAffectedByFocusWithin): Now uses m_nodeFlags.
(WebCore::Element::setDescendantsAffectedByPreviousSibling): Removed const qualifier & useless return.
(WebCore::Element::setStyleAffectedByActive): Now stores into m_rendererWithStyleFlags.
(WebCore::Element::setChildrenAffectedByDrag): Ditto.
(WebCore::Element::setChildrenAffectedByForwardPositionalRules): Ditto.
(WebCore::Element::setDescendantsAffectedByForwardPositionalRules): Ditto.
(WebCore::Element::setChildrenAffectedByBackwardPositionalRules): Ditto.
(WebCore::Element::setDescendantsAffectedByBackwardPositionalRules): Ditto.
(WebCore::Element::setChildrenAffectedByPropertyBasedBackwardPositionalRules): Ditto.
* dom/ElementRareData.h:
(WebCore::ElementRareData::styleAffectedByActive const): Deleted.
(WebCore::ElementRareData::setStyleAffectedByActive): Deleted.
(WebCore::ElementRareData::styleAffectedByEmpty const): Deleted.
(WebCore::ElementRareData::setStyleAffectedByEmpty): Deleted.
(WebCore::ElementRareData::styleAffectedByFocusWithin const): Deleted.
(WebCore::ElementRareData::setStyleAffectedByFocusWithin): Deleted.
(WebCore::ElementRareData::childrenAffectedByDrag const): Deleted.
(WebCore::ElementRareData::setChildrenAffectedByDrag): Deleted.
(WebCore::ElementRareData::childrenAffectedByLastChildRules const): Deleted.
(WebCore::ElementRareData::setChildrenAffectedByLastChildRules): Deleted.
(WebCore::ElementRareData::childrenAffectedByForwardPositionalRules const): Deleted.
(WebCore::ElementRareData::setChildrenAffectedByForwardPositionalRules): Deleted.
(WebCore::ElementRareData::descendantsAffectedByForwardPositionalRules const): Deleted.
(WebCore::ElementRareData::setDescendantsAffectedByForwardPositionalRules): Deleted.
(WebCore::ElementRareData::childrenAffectedByBackwardPositionalRules const): Deleted.
(WebCore::ElementRareData::setChildrenAffectedByBackwardPositionalRules): Deleted.
(WebCore::ElementRareData::descendantsAffectedByBackwardPositionalRules const): Deleted.
(WebCore::ElementRareData::setDescendantsAffectedByBackwardPositionalRules): Deleted.
(WebCore::ElementRareData::childrenAffectedByPropertyBasedBackwardPositionalRules const): Deleted.
(WebCore::ElementRareData::setChildrenAffectedByPropertyBasedBackwardPositionalRules): Deleted.
(WebCore::ElementRareData::useTypes const): Removed UseType::StyleFlags.
(WebCore::ElementRareData::ElementRareData): No longer takes RenderElement*.
(WebCore::ElementRareData::resetStyleRelations): Only re-sets child index now since that's all left.
* dom/Node.cpp:
(WebCore::stringForRareDataUseType): Removed UseType::StyleFlags since there is no style related
flags in ElementRareData.
(WebCore::Node::materializeRareData): Simplified now that m_rareData is not a union.
(WebCore::Node::clearRareData): Ditto.
* dom/Node.h:
(WebCore::NodeRareDataBase): Deleted.
(WebCore::Node::renderer const):
(WebCore::Node::rareDataMemoryOffset):
(WebCore::Node::flagHasRareData): Deleted.
(WebCore::Node::NodeFlags): Replaced HasRareDataFlag with StyleAffectedByFocusWithinFlag.
(WebCore::Node::ElementStyleFlag): Added.
(WebCore::Node::hasStyleFlag const): Added. Checks a reprense of a flag in m_rendererWithStyleFlags.
(WebCore::Node::setStyleFlag): Ditto for setting a flag.
(WebCore::Node::clearStyleFlags): Ditto for clearing all flags.
(WebCore::Node::hasRareData const): Now checks the nullity of m_rareData directly.
(WebCore::Node::rareData const):
* dom/NodeRareData.cpp: The size of NodeRareData is shrunk by one pointer.
* dom/NodeRareData.h:
(WebCore::NodeRareData::NodeRareData): No longer inherits from NodeRareDataBase which was needed to
to store RenderObject*.
(WebCore::Node::rareData const): Moved to Node.h.
* rendering/RenderObject.h:
(WebCore::Node::setRenderer): Moved from Node.h since CompactPointerTuple::setPointer has the
aforementioned static_assert which requires the definition of RenderObject.

Source/WTF:

Moved the static assert which requires the type of the object to which the pointer type points
into setPointer so that we can use CompactPointerTuple<T*, U> as a member variable
with just a forward declaration of T.

* wtf/CompactPointerTuple.h:
(WTF::CompactPointerTuple::setPointer):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@248807 268f45cc-cd09-0410-ab3c-d52691b4dbfc

12 files changed

tree: ce42a825bb1bdb26dbdd546e723cd8bc3fcbaa49

ReadMe.md

WebKit

WebKit is a cross-platform web browser engine. On iOS and macOS, it powers Safari, Mail, iBooks, and many other applications.

Feature Status

Visit WebKit Feature Status page to see which Web API has been implemented, in development, or under consideration.

Trying the Latest

On macOS, download Safari Technology Preview to test the latest version of WebKit. On Linux, download Epiphany Technology Preview. On Windows, you'll have to build it yourself.

Reporting Bugs

Search WebKit Bugzilla to see if there is an existing report for the bug you've encountered.
Create a Bugzilla account to to report bugs (and to comment on them) if you haven't done so already.
File a bug in accordance with our guidelines.

Once your bug is filed, you will receive email when it is updated at each stage in the bug life cycle. After the bug is considered fixed, you may be asked to download the latest nightly and confirm that the fix works for you.

Getting the Code

On Windows, follow the instructions on our website.

Cloning the Git SVN Repository

Run the following command to clone WebKit's Git SVN repository:

git clone git://git.webkit.org/WebKit.git WebKit

git clone https://git.webkit.org/git/WebKit.git WebKit

If you want to be able to commit changes to the repository, or just want to check out branches that aren’t contained in WebKit.git, you will need track WebKit's Subversion repository. You can run the following command to configure this and other options of the new Git clone for WebKit development.

Tools/Scripts/webkit-patch setup-git-clone

For information about this, and other aspects of using Git with WebKit, read the wiki page.

Checking out the Subversion Repository

If you don‘t want to use Git, run the following command to check out WebKit’s Subversion repository:

svn checkout https://svn.webkit.org/repository/webkit/trunk WebKit

Building WebKit

Building macOS Port

Install Xcode and its command line tools if you haven't done so already:

Install Xcode Get Xcode from https://developer.apple.com/downloads. To build WebKit for OS X, Xcode 5.1.1 or later is required. To build WebKit for iOS Simulator, Xcode 7 or later is required.
Install the Xcode Command Line Tools In Terminal, run the command: xcode-select --install

Run the following command to build a debug build with debugging symbols and assertions:

Tools/Scripts/build-webkit --debug

For performance testing, and other purposes, use --release instead.

Using Xcode

You can open WebKit.xcworkspace to build and debug WebKit within Xcode.

If you don't use a custom build location in Xcode preferences, you have to update the workspace settings to use WebKitBuild directory. In menu bar, choose File > Workspace Settings, then click the Advanced button, select “Custom”, “Relative to Workspace”, and enter WebKitBuild for both Products and Intermediates.

Building iOS Port

The first time after you install a new Xcode, you will need to run the following command to enable Xcode to build command line tools for iOS Simulator:

sudo Tools/Scripts/configure-xcode-for-ios-development

Without this step, you will see the error message: “target specifies product type ‘com.apple.product-type.tool’, but there’s no such product type for the ‘iphonesimulator’ platform.” when building target JSCLLIntOffsetsExtractor of project JavaScriptCore.

Run the following command to build a debug build with debugging symbols and assertions for iOS:

Tools/Scripts/build-webkit --debug --ios-simulator

Building the GTK+ Port

For production builds:

cmake -DPORT=GTK -DCMAKE_BUILD_TYPE=RelWithDebInfo -GNinja
ninja
sudo ninja install

For development builds:

Tools/gtk/install-dependencies
Tools/Scripts/update-webkitgtk-libs
Tools/Scripts/build-webkit --gtk --debug

For more information on building WebKitGTK+, see the wiki page.

Building the WPE Port

For production builds:

cmake -DPORT=WPE -DCMAKE_BUILD_TYPE=RelWithDebInfo -GNinja
ninja
sudo ninja install

For development builds:

Tools/wpe/install-dependencies
Tools/Scripts/update-webkitwpe-libs
Tools/Scripts/build-webkit --wpe --debug

Building Windows Port

For building WebKit on Windows, see the wiki page.

Running WebKit

With Safari and Other macOS Applications

Run the following command to launch Safari with your local build of WebKit:

Tools/Scripts/run-safari --debug

The run-safari script sets the DYLD_FRAMEWORK_PATH environment variable to point to your build products, and then launches /Applications/Safari.app. DYLD_FRAMEWORK_PATH tells the system loader to prefer your build products over the frameworks installed in /System/Library/Frameworks.

To run other applications with your local build of WebKit, run the following command:

Tools/Scripts/run-webkit-app <application-path>

iOS Simulator

Run the following command to launch iOS simulator with your local build of WebKit:

run-safari --debug --ios-simulator

In both cases, if you have built release builds instead, use --release instead of --debug.

Linux Ports

If you have a development build, you can use the run-minibrowser script, e.g.:

run-minibrowser --debug --wpe

Pass one of --gtk, --jsc-only, or --wpe to indicate the port to use.

Contribute

Congratulations! You’re up and running. Now you can begin coding in WebKit and contribute your fixes and new features to the project. For details on submitting your code to the project, read Contributing Code.