diff -r 000000000000 -r 6474c204b198 layout/style/nsRuleData.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/style/nsRuleData.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,129 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+/*
+ * temporary (expanded) representation of property-value pairs used to
+ * hold data from matched rules during style data computation.
+ */
+
+#ifndef nsRuleData_h_
+#define nsRuleData_h_
+
+#include "mozilla/CSSVariableDeclarations.h"
+#include "nsCSSProps.h"
+#include "nsCSSValue.h"
+#include "nsStyleStructFwd.h"
+
+class nsPresContext;
+class nsStyleContext;
+struct nsRuleData;
+
+typedef void (*nsPostResolveFunc)(void* aStyleStruct, nsRuleData* aData);
+
+struct nsRuleData
+{
+  const uint32_t mSIDs;
+  bool mCanStoreInRuleTree;
+  bool mIsImportantRule;
+  uint16_t mLevel; // an nsStyleSet::sheetType
+  nsPresContext* const mPresContext;
+  nsStyleContext* const mStyleContext;
+
+  // We store nsCSSValues needed to compute the data for one or more
+  // style structs (specified by the bitfield mSIDs).  These are stored
+  // in a single array allocation (which our caller allocates; see
+  // AutoCSSValueArray)   The offset of each property |prop| in
+  // mValueStorage is the sum of
+  // mValueOffsets[nsCSSProps::kSIDTable[prop]] and
+  // nsCSSProps::PropertyIndexInStruct(prop).  The only place we gather
+  // more than one style struct's data at a time is
+  // nsRuleNode::HasAuthorSpecifiedRules; therefore some code that we
+  // know is not called from HasAuthorSpecifiedRules assumes that the
+  // mValueOffsets for the one struct in mSIDs is zero.
+  nsCSSValue* const mValueStorage; // our user owns this array
+  size_t mValueOffsets[nsStyleStructID_Length];
+
+  nsAutoPtr<mozilla::CSSVariableDeclarations> mVariables;
+
+  nsRuleData(uint32_t aSIDs, nsCSSValue* aValueStorage,
+             nsPresContext* aContext, nsStyleContext* aStyleContext);
+
+#ifdef DEBUG
+  ~nsRuleData();
+#else
+  ~nsRuleData() {}
+#endif
+
+  /**
+   * Return a pointer to the value object within |this| corresponding
+   * to property |aProperty|.
+   *
+   * This function must only be called if the given property is in
+   * mSIDs.
+   */
+  nsCSSValue* ValueFor(nsCSSProperty aProperty)
+  {
+    NS_ABORT_IF_FALSE(aProperty < eCSSProperty_COUNT_no_shorthands,
+                      "invalid or shorthand property");
+
+    nsStyleStructID sid = nsCSSProps::kSIDTable[aProperty];
+    size_t indexInStruct = nsCSSProps::PropertyIndexInStruct(aProperty);
+
+    // This should really be nsCachedStyleData::GetBitForSID, but we can't
+    // include that here since it includes us.
+    NS_ABORT_IF_FALSE(mSIDs & (1 << sid),
+                      "calling nsRuleData::ValueFor on property not in mSIDs");
+    NS_ABORT_IF_FALSE(sid != eStyleStruct_BackendOnly &&
+                      indexInStruct != size_t(-1),
+                      "backend-only property");
+
+    return mValueStorage + mValueOffsets[sid] + indexInStruct;
+  }
+
+  const nsCSSValue* ValueFor(nsCSSProperty aProperty) const {
+    return const_cast<nsRuleData*>(this)->ValueFor(aProperty);
+  }
+
+  /**
+   * Getters like ValueFor(aProperty), but for each property by name
+   * (ValueForBackgroundColor, etc.), and more efficient than ValueFor.
+   * These use the names used for the property on DOM interfaces (the
+   * 'method' field in nsCSSPropList.h).
+   *
+   * Like ValueFor(), the caller must check that the property is within
+   * mSIDs.
+   */
+  #define CSS_PROP_PUBLIC_OR_PRIVATE(publicname_, privatename_) privatename_
+  #define CSS_PROP(name_, id_, method_, flags_, pref_, parsevariant_,        \
+                   kwtable_, stylestruct_, stylestructoffset_, animtype_)    \
+    nsCSSValue* ValueFor##method_() {                                        \
+      NS_ABORT_IF_FALSE(mSIDs & NS_STYLE_INHERIT_BIT(stylestruct_),          \
+                        "Calling nsRuleData::ValueFor" #method_ " without "  \
+                        "NS_STYLE_INHERIT_BIT(" #stylestruct_ " in mSIDs."); \
+      nsStyleStructID sid = eStyleStruct_##stylestruct_;                     \
+      size_t indexInStruct =                                                 \
+        nsCSSProps::PropertyIndexInStruct(eCSSProperty_##id_);               \
+      NS_ABORT_IF_FALSE(sid != eStyleStruct_BackendOnly &&                   \
+                        indexInStruct != size_t(-1),                         \
+                        "backend-only property");                            \
+      return mValueStorage + mValueOffsets[sid] + indexInStruct;             \
+    }                                                                        \
+    const nsCSSValue* ValueFor##method_() const {                            \
+      return const_cast<nsRuleData*>(this)->ValueFor##method_();             \
+    }
+  #define CSS_PROP_BACKENDONLY(name_, id_, method_, flags_, pref_,           \
+                             parsevariant_, kwtable_)                        \
+    /* empty; backend-only structs are not in nsRuleData  */
+  #include "nsCSSPropList.h"
+  #undef CSS_PROP
+  #undef CSS_PROP_PUBLIC_OR_PRIVATE
+  #undef CSS_PROP_BACKENDONLY
+
+private:
+  inline size_t GetPoisonOffset();
+
+};
+
+#endif