CSS Custom Properties (Variables)

Source/core/css/parser/CSSPropertyParser.cpp

Index: Source/core/css/parser/CSSPropertyParser.cpp
diff --git a/Source/core/css/parser/CSSPropertyParser.cpp b/Source/core/css/parser/CSSPropertyParser.cpp
index 10b55b207e1a9d87621a2c67b128c0698129f6b1..b79e63ded206cfab11ec9e95c766a34b04816eea 100644
--- a/Source/core/css/parser/CSSPropertyParser.cpp
+++ b/Source/core/css/parser/CSSPropertyParser.cpp
@@ -51,6 +51,7 @@
 #include "core/css/CSSTimingFunctionValue.h"
 #include "core/css/CSSUnicodeRangeValue.h"
 #include "core/css/CSSValuePool.h"
+#include "core/css/CSSVariableValue.h"
 #include "core/css/Counter.h"
 #include "core/css/HashTools.h"
 #include "core/css/Pair.h"
@@ -216,6 +217,9 @@ bool CSSPropertyParser::validCalculationUnit(CSSParserValue* value, Units unitfl
     case CalcFrequency:
         b = (unitflags & FFrequency);
         break;
+    case CalcVariable:
+        b = true;
+        break;
     case CalcOther:
         break;
     }
@@ -238,6 +242,9 @@ bool CSSPropertyParser::validUnit(CSSParserValue* value, Units unitflags, CSSPar
     if (isCalculation(value))
         return validCalculationUnit(value, unitflags, releaseCalc);
 
+    if (RuntimeEnabledFeatures::cssVariablesEnabled() && isVariableReference(value))
+        return true;
+
     if (unitflags & FNonNeg && value->fValue < 0)
         return false;
     switch (value->unit) {
@@ -297,6 +304,8 @@ PassRefPtrWillBeRawPtr<CSSPrimitiveValue> CSSPropertyParser::createPrimitiveNume
         ASSERT(isCalculation(value));
         return CSSPrimitiveValue::create(m_parsedCalculation.release());
     }
+    if (isVariableReference(value))
+        return createPrimitiveVariableReferenceValue(value);
 
     ASSERT((value->unit >= CSSPrimitiveValue::CSS_NUMBER && value->unit <= CSSPrimitiveValue::CSS_KHZ)
         || (value->unit >= CSSPrimitiveValue::CSS_TURN && value->unit <= CSSPrimitiveValue::CSS_CHS)
@@ -305,6 +314,12 @@ PassRefPtrWillBeRawPtr<CSSPrimitiveValue> CSSPropertyParser::createPrimitiveNume
     return cssValuePool().createValue(value->fValue, static_cast<CSSPrimitiveValue::UnitType>(value->unit));
 }
 
+inline PassRefPtrWillBeRawPtr<CSSPrimitiveValue> CSSPropertyParser::createPrimitiveVariableReferenceValue(CSSParserValue* value)
+{
+    ASSERT(value->unit == CSSParserValue::VariableValue);
+    return CSSPrimitiveValue::create(value->variableData);
+}
+
 inline PassRefPtrWillBeRawPtr<CSSPrimitiveValue> CSSPropertyParser::createPrimitiveStringValue(CSSParserValue* value)
 {
     ASSERT(value->unit == CSSPrimitiveValue::CSS_STRING || value->unit == CSSPrimitiveValue::CSS_IDENT);
@@ -395,6 +410,8 @@ inline PassRefPtrWillBeRawPtr<CSSPrimitiveValue> CSSPropertyParser::parseValidPr
         return CSSPrimitiveValue::createAllowingMarginQuirk(value->fValue, CSSPrimitiveValue::CSS_EMS);
     if (isCalculation(value))
         return CSSPrimitiveValue::create(m_parsedCalculation.release());
+    if (isVariableReference(value))
+        return createPrimitiveVariableReferenceValue(value);
 
     return nullptr;
 }
@@ -444,8 +461,16 @@ bool CSSPropertyParser::parseValue(CSSPropertyID unresolvedProperty, bool import
         return true;
     }
 
+
     int num = inShorthand() ? 1 : m_valueList->size();
 
+    if (RuntimeEnabledFeatures::cssVariablesEnabled() && isVariableReference(value)) {
+        // We don't expand the shorthand here because crazypants.
+        m_parsedProperties.append(CSSProperty(propId, createPrimitiveVariableReferenceValue(value), important, false, 0, m_implicitShorthand));
+        m_valueList->next();
+        return true;
+    }
+
     if (CSSParserFastPaths::isKeywordPropertyID(propId)) {
         if (!CSSParserFastPaths::isValidKeywordPropertyAndValue(propId, id))
             return false;
@@ -1494,7 +1519,6 @@ bool CSSPropertyParser::parseValue(CSSPropertyID unresolvedProperty, bool import
     case CSSPropertyUserZoom:
         validPrimitive = false;
         break;
-
     case CSSPropertyScrollSnapPointsX:
     case CSSPropertyScrollSnapPointsY:
         parsedValue = parseScrollSnapPoints();
@@ -1504,8 +1528,6 @@ bool CSSPropertyParser::parseValue(CSSPropertyID unresolvedProperty, bool import
         break;
     case CSSPropertyScrollSnapDestination:
         parsedValue = parsePosition(m_valueList);
-        break;
-
     default:
         return parseSVGValue(propId, important);
     }
@@ -5158,6 +5180,11 @@ bool CSSPropertyParser::isCalculation(CSSParserValue* value)
             || value->function->id == CSSValueWebkitCalc);
 }
 
+bool CSSPropertyParser::isVariableReference(CSSParserValue* value)
+{
+    return value->unit == CSSParserValue::VariableValue;
+}
+
 inline int CSSPropertyParser::colorIntFromValue(CSSParserValue* v)
 {
     bool isPercent;
@@ -5526,15 +5553,19 @@ PassRefPtrWillBeRawPtr<CSSValue> CSSPropertyParser::parseReflect()
     // Direction comes first.
     CSSParserValue* val = m_valueList->current();
     RefPtrWillBeRawPtr<CSSPrimitiveValue> direction = nullptr;
-    switch (val->id) {
-    case CSSValueAbove:
-    case CSSValueBelow:
-    case CSSValueLeft:
-    case CSSValueRight:
-        direction = cssValuePool().createIdentifierValue(val->id);
-        break;
-    default:
-        return nullptr;
+    if (isVariableReference(val)) {
+        direction = createPrimitiveVariableReferenceValue(val);
+    } else {
+        switch (val->id) {
+        case CSSValueAbove:
+        case CSSValueBelow:
+        case CSSValueLeft:
+        case CSSValueRight:
+            direction = cssValuePool().createIdentifierValue(val->id);
+            break;
+        default:
+            return nullptr;
+        }
     }
 
     // The offset comes next.
@@ -7794,22 +7825,34 @@ bool CSSPropertyParser::parseViewportShorthand(CSSPropertyID propId, CSSProperty
 }
 
 template <typename CharacterType>
+static bool isVariableDefinition(const CharacterType* propertyName, unsigned length)
+{
+    return (length >= 2 && propertyName[0] == '-' && propertyName[1] == '-');
+}
+
+template <typename CharacterType>
 static CSSPropertyID unresolvedCSSPropertyID(const CharacterType* propertyName, unsigned length)
 {
     char buffer[maxCSSPropertyNameLength + 1]; // 1 for null character
 
     for (unsigned i = 0; i != length; ++i) {
         CharacterType c = propertyName[i];
-        if (c == 0 || c >= 0x7F)
+        if (c == 0 || c >= 0x7F) {
+            if (isVariableDefinition(propertyName, length))
+                return CSSPropertyVariable;
             return CSSPropertyInvalid; // illegal character
+        }
         buffer[i] = toASCIILower(c);
     }
     buffer[length] = '\0';
 
     const char* name = buffer;
     const Property* hashTableEntry = findProperty(name, length);
-    if (!hashTableEntry)
+    if (!hashTableEntry) {
+        if (isVariableDefinition(propertyName, length))
+            return CSSPropertyVariable;
         return CSSPropertyInvalid;
+    }
     CSSPropertyID property = static_cast<CSSPropertyID>(hashTableEntry->id);
     if (!CSSPropertyMetadata::isEnabledProperty(property))
         return CSSPropertyInvalid;
@@ -7822,8 +7865,11 @@ CSSPropertyID unresolvedCSSPropertyID(const String& string)
 
     if (!length)
         return CSSPropertyInvalid;
-    if (length > maxCSSPropertyNameLength)
+    if (length > maxCSSPropertyNameLength) {
+        if (string.is8Bit() ? isVariableDefinition(string.characters8(), length) : isVariableDefinition(string.characters8(), length))
+            return CSSPropertyVariable;
         return CSSPropertyInvalid;
+    }
 
     return string.is8Bit() ? unresolvedCSSPropertyID(string.characters8(), length) : unresolvedCSSPropertyID(string.characters16(), length);
 }