DataRef<T> should use Ref<T> internally.

<https://webkit.org/b/122953>

DataRef is used to hold RenderStyle substructures, and due to the
way style inheritance is implemented, DataRef will always point to
a live object.

Codify this by making DataRef::m_data a Ref, and making all methods
that create substructure objects return PassRef.

Reviewed by Antti Koivisto.

Canonical link: https://commits.webkit.org/141030@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@157568 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/WebCore/ChangeLog

@@ -1,3 +1,17 @@
+2013-10-17  Andreas Kling  <akling@apple.com>
+
+        DataRef<T> should use Ref<T> internally.
+        <https://webkit.org/b/122953>
+
+        DataRef is used to hold RenderStyle substructures, and due to the
+        way style inheritance is implemented, DataRef will always point to
+        a live object.
+
+        Codify this by making DataRef::m_data a Ref, and making all methods
+        that create substructure objects return PassRef.
+
+        Reviewed by Antti Koivisto.
+
 2013-10-17  Mihnea Ovidenie  <mihnea@adobe.com>
 
         [CSS Regions] Anonymous nested regions

Source/WebCore/rendering/style/DataRef.h

@@ -24,13 +24,18 @@
 #ifndef DataRef_h
 #define DataRef_h
 
-#include <wtf/RefPtr.h>
+#include <wtf/PassRef.h>
+#include <wtf/Ref.h>
 
 namespace WebCore {
 
 template <typename T> class DataRef {
 public:
-    const T* get() const { return m_data.get(); }
+    DataRef(PassRef<T> data) : m_data(std::move(data)) { }
+    DataRef(const DataRef& other) : m_data(const_cast<T&>(other.m_data.get())) { }
+    DataRef& operator=(const DataRef& other) { m_data = const_cast<T&>(other.m_data.get()); return *this; }
+
+    const T* get() const { return &m_data.get(); }
 
     const T& operator*() const { return *get(); }
     const T* operator->() const { return get(); }
@@ -39,31 +44,21 @@ template <typename T> class DataRef {
     {
         if (!m_data->hasOneRef())
             m_data = m_data->copy();
-        return m_data.get();
-    }
-
-    void init()
-    {
-        ASSERT(!m_data);
-        m_data = T::create();
+        return &m_data.get();
     }
 
     bool operator==(const DataRef<T>& o) const
     {
-        ASSERT(m_data);
-        ASSERT(o.m_data);
-        return m_data == o.m_data || *m_data == *o.m_data;
+        return &m_data.get() == &o.m_data.get() || m_data.get() == o.m_data.get();
     }
 
     bool operator!=(const DataRef<T>& o) const
     {
-        ASSERT(m_data);
-        ASSERT(o.m_data);
-        return m_data != o.m_data && *m_data != *o.m_data;
+        return &m_data.get() != &o.m_data.get() && m_data.get() != o.m_data.get();
     }
 
 private:
-    RefPtr<T> m_data;
+    Ref<T> m_data;
 };
 
 } // namespace WebCore

Source/WebCore/rendering/style/NinePieceImage.cpp

@@ -23,15 +23,14 @@
 
 #include "config.h"
 #include "NinePieceImage.h"
+#include <wtf/NeverDestroyed.h>
 
 namespace WebCore {
 
 static DataRef<NinePieceImageData>& defaultData()
 {
-    static DataRef<NinePieceImageData>* data = new DataRef<NinePieceImageData>;
-    if (!data->get())
-        data->init();
-    return *data;
+    static NeverDestroyed<DataRef<NinePieceImageData>> data(NinePieceImageData::create());
+    return data.get();
 }
 
 NinePieceImage::NinePieceImage()
@@ -40,8 +39,8 @@ NinePieceImage::NinePieceImage()
 }
 
 NinePieceImage::NinePieceImage(PassRefPtr<StyleImage> image, LengthBox imageSlices, bool fill, LengthBox borderSlices, LengthBox outset, ENinePieceImageRule horizontalRule, ENinePieceImageRule verticalRule)
+    : m_data(NinePieceImageData::create())
 {
-    m_data.init();
     m_data.access()->image = image;
     m_data.access()->imageSlices = std::move(imageSlices);
     m_data.access()->borderSlices = std::move(borderSlices);

Source/WebCore/rendering/style/NinePieceImage.h

@@ -37,8 +37,8 @@ enum ENinePieceImageRule {
 
 class NinePieceImageData : public RefCounted<NinePieceImageData> {
 public:
-    static PassRefPtr<NinePieceImageData> create() { return adoptRef(new NinePieceImageData); }
-    PassRefPtr<NinePieceImageData> copy() const { return adoptRef(new NinePieceImageData(*this)); }
+    static PassRef<NinePieceImageData> create() { return adoptRef(*new NinePieceImageData); }
+    PassRef<NinePieceImageData> copy() const { return adoptRef(*new NinePieceImageData(*this)); }
 
     bool operator==(const NinePieceImageData&) const;
     bool operator!=(const NinePieceImageData& o) const { return !(*this == o); }

Source/WebCore/rendering/style/RenderStyle.cpp

@@ -128,29 +128,16 @@ ALWAYS_INLINE RenderStyle::RenderStyle()
 }
 
 ALWAYS_INLINE RenderStyle::RenderStyle(bool)
+    : m_box(StyleBoxData::create())
+    , visual(StyleVisualData::create())
+    , m_background(StyleBackgroundData::create())
+    , surround(StyleSurroundData::create())
+    , rareNonInheritedData(StyleRareNonInheritedData::create())
+    , rareInheritedData(StyleRareInheritedData::create())
+    , inherited(StyleInheritedData::create())
+    , m_svgStyle(SVGRenderStyle::create())
 {
     setBitDefaults();
-
-    m_box.init();
-    visual.init();
-    m_background.init();
-    surround.init();
-    rareNonInheritedData.init();
-    rareNonInheritedData.access()->m_deprecatedFlexibleBox.init();
-    rareNonInheritedData.access()->m_flexibleBox.init();
-    rareNonInheritedData.access()->m_marquee.init();
-    rareNonInheritedData.access()->m_multiCol.init();
-    rareNonInheritedData.access()->m_transform.init();
-#if ENABLE(CSS_FILTERS)
-    rareNonInheritedData.access()->m_filter.init();
-#endif
-    rareNonInheritedData.access()->m_grid.init();
-    rareNonInheritedData.access()->m_gridItem.init();
-    rareInheritedData.init();
-    inherited.init();
-#if ENABLE(SVG)
-    m_svgStyle.init();
-#endif
 }
 
 ALWAYS_INLINE RenderStyle::RenderStyle(const RenderStyle& o)

Source/WebCore/rendering/style/SVGRenderStyle.cpp

@@ -35,55 +35,62 @@
 #include "IntRect.h"
 #include "NodeRenderStyle.h"
 #include "SVGElement.h"
+#include <wtf/NeverDestroyed.h>
 
 using namespace std;
 
 namespace WebCore {
 
-SVGRenderStyle::SVGRenderStyle()
+static const SVGRenderStyle& defaultSVGStyle()
 {
-    static SVGRenderStyle* defaultStyle = new SVGRenderStyle(CreateDefault);
+    static NeverDestroyed<DataRef<SVGRenderStyle>> style(SVGRenderStyle::createDefaultStyle());
+    return *style.get().get();
+}
 
-    fill = defaultStyle->fill;
-    stroke = defaultStyle->stroke;
-    text = defaultStyle->text;
-    stops = defaultStyle->stops;
-    misc = defaultStyle->misc;
-    shadowSVG = defaultStyle->shadowSVG;
-    inheritedResources = defaultStyle->inheritedResources;
-    resources = defaultStyle->resources;
+PassRef<SVGRenderStyle> SVGRenderStyle::createDefaultStyle()
+{
+    return adoptRef(*new SVGRenderStyle(CreateDefault));
+}
 
+SVGRenderStyle::SVGRenderStyle()
+    : fill(defaultSVGStyle().fill)
+    , stroke(defaultSVGStyle().stroke)
+    , text(defaultSVGStyle().text)
+    , inheritedResources(defaultSVGStyle().inheritedResources)
+    , stops(defaultSVGStyle().stops)
+    , misc(defaultSVGStyle().misc)
+    , shadowSVG(defaultSVGStyle().shadowSVG)
+    , resources(defaultSVGStyle().resources)
+{
     setBitDefaults();
 }
 
 SVGRenderStyle::SVGRenderStyle(CreateDefaultType)
+    : fill(StyleFillData::create())
+    , stroke(StyleStrokeData::create())
+    , text(StyleTextData::create())
+    , inheritedResources(StyleInheritedResourceData::create())
+    , stops(StyleStopData::create())
+    , misc(StyleMiscData::create())
+    , shadowSVG(StyleShadowSVGData::create())
+    , resources(StyleResourceData::create())
 {
     setBitDefaults();
-
-    fill.init();
-    stroke.init();
-    text.init();
-    stops.init();
-    misc.init();
-    shadowSVG.init();
-    inheritedResources.init();
-    resources.init();
 }
 
 SVGRenderStyle::SVGRenderStyle(const SVGRenderStyle& other)
     : RefCounted<SVGRenderStyle>()
+    , svg_inherited_flags(other.svg_inherited_flags)
+    , svg_noninherited_flags(other.svg_noninherited_flags)
+    , fill(other.fill)
+    , stroke(other.stroke)
+    , text(other.text)
+    , inheritedResources(other.inheritedResources)
+    , stops(other.stops)
+    , misc(other.misc)
+    , shadowSVG(other.shadowSVG)
+    , resources(other.resources)
 {
-    fill = other.fill;
-    stroke = other.stroke;
-    text = other.text;
-    stops = other.stops;
-    misc = other.misc;
-    shadowSVG = other.shadowSVG;
-    inheritedResources = other.inheritedResources;
-    resources = other.resources;
-
-    svg_inherited_flags = other.svg_inherited_flags;
-    svg_noninherited_flags = other.svg_noninherited_flags;
 }
 
 SVGRenderStyle::~SVGRenderStyle()

Source/WebCore/rendering/style/SVGRenderStyle.h

@@ -41,8 +41,9 @@ class RenderObject;
 
 class SVGRenderStyle : public RefCounted<SVGRenderStyle> {    
 public:
-    static PassRefPtr<SVGRenderStyle> create() { return adoptRef(new SVGRenderStyle); }
-    PassRefPtr<SVGRenderStyle> copy() const { return adoptRef(new SVGRenderStyle(*this));}
+    static PassRef<SVGRenderStyle> createDefaultStyle();
+    static PassRef<SVGRenderStyle> create() { return adoptRef(*new SVGRenderStyle); }
+    PassRef<SVGRenderStyle> copy() const { return adoptRef(*new SVGRenderStyle(*this));}
     ~SVGRenderStyle();
 
     bool inheritedNotEqual(const SVGRenderStyle*) const;

Source/WebCore/rendering/style/SVGRenderStyleDefs.h

@@ -101,8 +101,8 @@ namespace WebCore {
     // Inherited/Non-Inherited Style Datastructures
     class StyleFillData : public RefCounted<StyleFillData> {
     public:
-        static PassRefPtr<StyleFillData> create() { return adoptRef(new StyleFillData); }
-        PassRefPtr<StyleFillData> copy() const { return adoptRef(new StyleFillData(*this)); }
+        static PassRef<StyleFillData> create() { return adoptRef(*new StyleFillData); }
+        PassRef<StyleFillData> copy() const { return adoptRef(*new StyleFillData(*this)); }
 
         bool operator==(const StyleFillData&) const;
         bool operator!=(const StyleFillData& other) const
@@ -125,8 +125,8 @@ namespace WebCore {
 
     class StyleStrokeData : public RefCounted<StyleStrokeData> {
     public:
-        static PassRefPtr<StyleStrokeData> create() { return adoptRef(new StyleStrokeData); }
-        PassRefPtr<StyleStrokeData> copy() const { return adoptRef(new StyleStrokeData(*this)); }
+        static PassRef<StyleStrokeData> create() { return adoptRef(*new StyleStrokeData); }
+        PassRef<StyleStrokeData> copy() const { return adoptRef(*new StyleStrokeData(*this)); }
 
         bool operator==(const StyleStrokeData&) const;
         bool operator!=(const StyleStrokeData& other) const
@@ -155,8 +155,8 @@ namespace WebCore {
 
     class StyleStopData : public RefCounted<StyleStopData> {
     public:
-        static PassRefPtr<StyleStopData> create() { return adoptRef(new StyleStopData); }
-        PassRefPtr<StyleStopData> copy() const { return adoptRef(new StyleStopData(*this)); }
+        static PassRef<StyleStopData> create() { return adoptRef(*new StyleStopData); }
+        PassRef<StyleStopData> copy() const { return adoptRef(*new StyleStopData(*this)); }
 
         bool operator==(const StyleStopData&) const;
         bool operator!=(const StyleStopData& other) const
@@ -174,8 +174,8 @@ namespace WebCore {
 
     class StyleTextData : public RefCounted<StyleTextData> {
     public:
-        static PassRefPtr<StyleTextData> create() { return adoptRef(new StyleTextData); }
-        PassRefPtr<StyleTextData> copy() const { return adoptRef(new StyleTextData(*this)); }
+        static PassRef<StyleTextData> create() { return adoptRef(*new StyleTextData); }
+        PassRef<StyleTextData> copy() const { return adoptRef(*new StyleTextData(*this)); }
 
         bool operator==(const StyleTextData& other) const;
         bool operator!=(const StyleTextData& other) const
@@ -193,8 +193,8 @@ namespace WebCore {
     // Note: the rule for this class is, *no inheritance* of these props
     class StyleMiscData : public RefCounted<StyleMiscData> {
     public:
-        static PassRefPtr<StyleMiscData> create() { return adoptRef(new StyleMiscData); }
-        PassRefPtr<StyleMiscData> copy() const { return adoptRef(new StyleMiscData(*this)); }
+        static PassRef<StyleMiscData> create() { return adoptRef(*new StyleMiscData); }
+        PassRef<StyleMiscData> copy() const { return adoptRef(*new StyleMiscData(*this)); }
 
         bool operator==(const StyleMiscData&) const;
         bool operator!=(const StyleMiscData& other) const
@@ -216,8 +216,8 @@ namespace WebCore {
 
     class StyleShadowSVGData : public RefCounted<StyleShadowSVGData> {
     public:
-        static PassRefPtr<StyleShadowSVGData> create() { return adoptRef(new StyleShadowSVGData); }
-        PassRefPtr<StyleShadowSVGData> copy() const { return adoptRef(new StyleShadowSVGData(*this)); }
+        static PassRef<StyleShadowSVGData> create() { return adoptRef(*new StyleShadowSVGData); }
+        PassRef<StyleShadowSVGData> copy() const { return adoptRef(*new StyleShadowSVGData(*this)); }
 
         bool operator==(const StyleShadowSVGData&) const;
         bool operator!=(const StyleShadowSVGData& other) const
@@ -235,8 +235,8 @@ namespace WebCore {
     // Non-inherited resources
     class StyleResourceData : public RefCounted<StyleResourceData> {
     public:
-        static PassRefPtr<StyleResourceData> create() { return adoptRef(new StyleResourceData); }
-        PassRefPtr<StyleResourceData> copy() const { return adoptRef(new StyleResourceData(*this)); }
+        static PassRef<StyleResourceData> create() { return adoptRef(*new StyleResourceData); }
+        PassRef<StyleResourceData> copy() const { return adoptRef(*new StyleResourceData(*this)); }
 
         bool operator==(const StyleResourceData&) const;
         bool operator!=(const StyleResourceData& other) const
@@ -256,8 +256,8 @@ namespace WebCore {
     // Inherited resources
     class StyleInheritedResourceData : public RefCounted<StyleInheritedResourceData> {
     public:
-        static PassRefPtr<StyleInheritedResourceData> create() { return adoptRef(new StyleInheritedResourceData); }
-        PassRefPtr<StyleInheritedResourceData> copy() const { return adoptRef(new StyleInheritedResourceData(*this)); }
+        static PassRef<StyleInheritedResourceData> create() { return adoptRef(*new StyleInheritedResourceData); }
+        PassRef<StyleInheritedResourceData> copy() const { return adoptRef(*new StyleInheritedResourceData(*this)); }
 
         bool operator==(const StyleInheritedResourceData&) const;
         bool operator!=(const StyleInheritedResourceData& other) const

Source/WebCore/rendering/style/StyleBackgroundData.h

@@ -35,8 +35,8 @@ namespace WebCore {
 
 class StyleBackgroundData : public RefCounted<StyleBackgroundData> {
 public:
-    static PassRefPtr<StyleBackgroundData> create() { return adoptRef(new StyleBackgroundData); }
-    PassRefPtr<StyleBackgroundData> copy() const { return adoptRef(new StyleBackgroundData(*this)); }
+    static PassRef<StyleBackgroundData> create() { return adoptRef(*new StyleBackgroundData); }
+    PassRef<StyleBackgroundData> copy() const { return adoptRef(*new StyleBackgroundData(*this)); }
     ~StyleBackgroundData() { }
 
     bool operator==(const StyleBackgroundData& o) const;

Source/WebCore/rendering/style/StyleBoxData.h

@@ -34,8 +34,8 @@ namespace WebCore {
 
 class StyleBoxData : public RefCounted<StyleBoxData> {
 public:
-    static PassRefPtr<StyleBoxData> create() { return adoptRef(new StyleBoxData); }
-    PassRefPtr<StyleBoxData> copy() const { return adoptRef(new StyleBoxData(*this)); }
+    static PassRef<StyleBoxData> create() { return adoptRef(*new StyleBoxData); }
+    PassRef<StyleBoxData> copy() const { return adoptRef(*new StyleBoxData(*this)); }
 
     bool operator==(const StyleBoxData& o) const;
     bool operator!=(const StyleBoxData& o) const

Source/WebCore/rendering/style/StyleDeprecatedFlexibleBoxData.h

@@ -32,8 +32,8 @@ namespace WebCore {
 
 class StyleDeprecatedFlexibleBoxData : public RefCounted<StyleDeprecatedFlexibleBoxData> {
 public:
-    static PassRefPtr<StyleDeprecatedFlexibleBoxData> create() { return adoptRef(new StyleDeprecatedFlexibleBoxData); }
-    PassRefPtr<StyleDeprecatedFlexibleBoxData> copy() const { return adoptRef(new StyleDeprecatedFlexibleBoxData(*this)); }
+    static PassRef<StyleDeprecatedFlexibleBoxData> create() { return adoptRef(*new StyleDeprecatedFlexibleBoxData); }
+    PassRef<StyleDeprecatedFlexibleBoxData> copy() const { return adoptRef(*new StyleDeprecatedFlexibleBoxData(*this)); }
 
     bool operator==(const StyleDeprecatedFlexibleBoxData&) const;
     bool operator!=(const StyleDeprecatedFlexibleBoxData& o) const

Source/WebCore/rendering/style/StyleFilterData.h

@@ -36,8 +36,8 @@ namespace WebCore {
 
 class StyleFilterData : public RefCounted<StyleFilterData> {
 public:
-    static PassRefPtr<StyleFilterData> create() { return adoptRef(new StyleFilterData); }
-    PassRefPtr<StyleFilterData> copy() const { return adoptRef(new StyleFilterData(*this)); }
+    static PassRef<StyleFilterData> create() { return adoptRef(*new StyleFilterData); }
+    PassRef<StyleFilterData> copy() const { return adoptRef(*new StyleFilterData(*this)); }
 
     bool operator==(const StyleFilterData&) const;
     bool operator!=(const StyleFilterData& o) const