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// Copyright 2015 The Chromium Authors. All rights reserved.
// Copyright (C) 2016-2021 Apple Inc. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "config.h"
#include "CSSVariableParser.h"
#include "CSSCustomPropertyValue.h"
#include "CSSParserContext.h"
#include "CSSParserIdioms.h"
#include "CSSParserTokenRange.h"
#include "CSSPropertyParser.h"
#include "CSSPropertyParserConsumer+Primitives.h"
#include "CSSTokenizer.h"
namespace WebCore {
bool CSSVariableParser::isValidVariableName(const CSSParserToken& token)
{
if (token.type() != IdentToken)
return false;
return isCustomPropertyName(token.value());
}
static bool isValidConstantName(const CSSParserToken& token)
{
return token.type() == IdentToken;
}
static bool isValidVariableReference(CSSParserTokenRange, const CSSParserContext&);
static bool isValidConstantReference(CSSParserTokenRange, const CSSParserContext&);
static bool classifyBlock(CSSParserTokenRange range, bool& hasReferences, bool& hasTopLevelBraceBlockMixedWithOtherValues, const CSSParserContext& parserContext, bool isTopLevelBlock = true)
{
unsigned topLevelBraceBlocks = 0;
bool hasOtherValuesThanTopLevelBraceBlock = false;
while (!range.atEnd()) {
if (isTopLevelBlock) {
auto tokenType = range.peek().type();
if (!CSSTokenizer::isWhitespace(tokenType)) {
if (tokenType == LeftBraceToken)
topLevelBraceBlocks++;
else
hasOtherValuesThanTopLevelBraceBlock = true;
}
}
if (range.peek().getBlockType() == CSSParserToken::BlockStart) {
const CSSParserToken& token = range.peek();
CSSParserTokenRange block = range.consumeBlock();
if (token.functionId() == CSSValueVar) {
if (!isValidVariableReference(block, parserContext))
return false; // Bail if any references are invalid
hasReferences = true;
continue;
}
if (token.functionId() == CSSValueEnv) {
if (!isValidConstantReference(block, parserContext))
return false; // Bail if any references are invalid
hasReferences = true;
continue;
}
if (!classifyBlock(block, hasReferences, hasTopLevelBraceBlockMixedWithOtherValues, parserContext, false))
return false;
continue;
}
ASSERT(range.peek().getBlockType() != CSSParserToken::BlockEnd);
const CSSParserToken& token = range.consume();
switch (token.type()) {
case AtKeywordToken:
break;
case DelimiterToken: {
if (token.delimiter() == '!' && isTopLevelBlock)
return false;
break;
}
case RightParenthesisToken:
case RightBraceToken:
case RightBracketToken:
case BadStringToken:
case BadUrlToken:
return false;
case SemicolonToken:
if (isTopLevelBlock)
return false;
break;
default:
break;
}
}
// If there is a top level brace block, the value should contains only that.
if (topLevelBraceBlocks > 1 || (topLevelBraceBlocks == 1 && hasOtherValuesThanTopLevelBraceBlock))
hasTopLevelBraceBlockMixedWithOtherValues = true;
return true;
}
bool isValidVariableReference(CSSParserTokenRange range, const CSSParserContext& parserContext)
{
range.consumeWhitespace();
if (!CSSVariableParser::isValidVariableName(range.consumeIncludingWhitespace()))
return false;
if (range.atEnd())
return true;
if (!CSSPropertyParserHelpers::consumeCommaIncludingWhitespace(range))
return false;
if (range.atEnd())
return true;
bool hasReferences = false;
bool hasTopLevelBraceBlock = false;
return classifyBlock(range, hasReferences, hasTopLevelBraceBlock, parserContext);
}
bool isValidConstantReference(CSSParserTokenRange range, const CSSParserContext& parserContext)
{
range.consumeWhitespace();
if (!isValidConstantName(range.consumeIncludingWhitespace()))
return false;
if (range.atEnd())
return true;
if (!CSSPropertyParserHelpers::consumeCommaIncludingWhitespace(range))
return false;
if (range.atEnd())
return true;
bool hasReferences = false;
bool hasTopLevelBraceBlock = false;
return classifyBlock(range, hasReferences, hasTopLevelBraceBlock, parserContext);
}
struct VariableType {
std::optional<CSSValueID> cssWideKeyword { };
bool hasReferences { false };
bool hasTopLevelBraceBlockWithOtherValues { false };
};
static std::optional<VariableType> classifyVariableRange(CSSParserTokenRange range, const CSSParserContext& parserContext)
{
range.consumeWhitespace();
if (range.peek().type() == IdentToken) {
auto rangeCopy = range;
CSSValueID id = range.consumeIncludingWhitespace().id();
if (range.atEnd() && isCSSWideKeyword(id))
return VariableType { id };
// No fast path, restart with the complete range.
range = rangeCopy;
}
VariableType type;
if (!classifyBlock(range, type.hasReferences, type.hasTopLevelBraceBlockWithOtherValues, parserContext))
return { };
return type;
}
bool CSSVariableParser::containsValidVariableReferences(CSSParserTokenRange range, const CSSParserContext& parserContext)
{
auto type = classifyVariableRange(range, parserContext);
if (!type)
return false;
return type->hasReferences && !type->hasTopLevelBraceBlockWithOtherValues;
}
RefPtr<CSSCustomPropertyValue> CSSVariableParser::parseDeclarationValue(const AtomString& variableName, CSSParserTokenRange range, const CSSParserContext& parserContext)
{
if (range.atEnd())
return nullptr;
auto type = classifyVariableRange(range, parserContext);
if (!type)
return nullptr;
if (type->cssWideKeyword)
return CSSCustomPropertyValue::createWithID(variableName, *type->cssWideKeyword);
if (type->hasReferences)
return CSSCustomPropertyValue::createUnresolved(variableName, CSSVariableReferenceValue::create(range, parserContext));
return CSSCustomPropertyValue::createSyntaxAll(variableName, CSSVariableData::create(range, parserContext));
}
RefPtr<CSSCustomPropertyValue> CSSVariableParser::parseInitialValueForUniversalSyntax(const AtomString& variableName, CSSParserTokenRange range)
{
if (range.atEnd())
return nullptr;
auto type = classifyVariableRange(range, strictCSSParserContext());
if (!type || type->cssWideKeyword || type->hasReferences)
return nullptr;
return CSSCustomPropertyValue::createSyntaxAll(variableName, CSSVariableData::create(range));
}
} // namespace WebCore
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