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 dec461d15a9cd94c32b91565961a6fb6be3b9e74..90dfdc176760beb8b015ad365c0ffc0171ae88c8 100644
--- a/Source/core/css/parser/CSSPropertyParser.cpp
+++ b/Source/core/css/parser/CSSPropertyParser.cpp
@@ -34,6 +34,7 @@
 #include "core/css/CSSContentDistributionValue.h"
 #include "core/css/CSSCrossfadeValue.h"
 #include "core/css/CSSCursorImageValue.h"
+#include "core/css/CSSCustomVariableValue.h"
 #include "core/css/CSSFontFaceSrcValue.h"
 #include "core/css/CSSFontFeatureValue.h"
 #include "core/css/CSSFunctionValue.h"
@@ -446,8 +447,16 @@ bool CSSPropertyParser::parseValue(CSSPropertyID unresolvedProperty, bool import
         return true;
     }
 
+
     int num = inShorthand() ? 1 : m_valueList->size();
 
+    if (RuntimeEnabledFeatures::cssVariablesEnabled() && value->unit() == CSSPrimitiveValue::UnitType::VariableReference) {
+        // We don't expand the shorthand here because crazypants.
+        m_parsedProperties.append(CSSProperty(propId, CSSPrimitiveValue::create(value->variableData), important, false, 0, m_implicitShorthand));
+        m_valueList->next();
+        return true;
+    }
+
     if (CSSParserFastPaths::isKeywordPropertyID(propId)) {
         if (!CSSParserFastPaths::isValidKeywordPropertyAndValue(propId, id))
             return false;
@@ -7582,22 +7591,34 @@ 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)

[alancutter (OOO until 2018), 2015/08/05 08:01:43]

I'm not sure that we should be returning CSSPropertyVariable from this function.
Existing calls to it are unlikely going to handle the custom property case
correctly since it's not a real property identifier.
It's probably better to continue returning CSSPropertyInvalid and at the call
site just call isVariableDefinition() on the original string. I suspect existing
call sites like transition-property parsing will not want to treat them any
differently from CSSPropertyInvalid.

 {
     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;
@@ -7610,8 +7631,11 @@ CSSPropertyID unresolvedCSSPropertyID(const String& string)
 
     if (!length)
         return CSSPropertyInvalid;
-    if (length > maxCSSPropertyNameLength)
+    if (length > maxCSSPropertyNameLength) {
+        if (string.is8Bit() ? isVariableDefinition(string.characters8(), length) : isVariableDefinition(string.characters16(), length))
+            return CSSPropertyVariable;
         return CSSPropertyInvalid;
+    }
 
     return string.is8Bit() ? unresolvedCSSPropertyID(string.characters8(), length) : unresolvedCSSPropertyID(string.characters16(), length);
 }
@@ -7622,8 +7646,11 @@ CSSPropertyID unresolvedCSSPropertyID(const CSSParserString& string)
 
     if (!length)
         return CSSPropertyInvalid;
-    if (length > maxCSSPropertyNameLength)
+    if (length > maxCSSPropertyNameLength) {
+        if (string.is8Bit() ? isVariableDefinition(string.characters8(), length) : isVariableDefinition(string.characters16(), length))
+            return CSSPropertyVariable;
         return CSSPropertyInvalid;
+    }
 
     return string.is8Bit() ? unresolvedCSSPropertyID(string.characters8(), length) : unresolvedCSSPropertyID(string.characters16(), length);
 }