| /* |
| * Copyright (C) 2026 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: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. 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. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS 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 APPLE INC. OR ITS 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 "CSSRandomKeyParser.h" |
| |
| #include "CSSParserTokenRange.h" |
| #include "CSSParserTokenRangeGuard.h" |
| #include "CSSPropertyParser.h" |
| #include "CSSPropertyParserConsumer+Ident.h" |
| #include "CSSPropertyParserConsumer+MetaConsumer.h" |
| #include "CSSPropertyParserConsumer+NumberDefinitions.h" |
| #include "CSSPropertyParserState.h" |
| #include "CSSValueKeywords.h" |
| #include <wtf/StdLibExtras.h> |
| #include <wtf/text/StringToIntegerConversion.h> |
| |
| namespace WebCore { |
| namespace CSSPropertyParserHelpers { |
| |
| // <random-ua-ident> = ua- PROPERTY [ - INDEX ]?, where INDEX is 1-based. Returns nullopt when the |
| // ident does not name a known property, which makes the whole <random-key> invalid. |
| // FIXME: ยง 9.4.1 also spells an in-custom-function form, ua-FUNCTIONNAME-PROPERTY[-INDEX]. Both names |
| // can contain hyphens, so splitting it is ambiguous; see https://github.com/w3c/csswg-drafts/issues/14330 |
| static std::optional<Variant<CSSCalc::Random::Key::PropertyScoped, CSSCalc::Random::Key::PropertyIndexScoped>> parseRandomUAIdent(StringView ident) |
| { |
| auto body = ident.substring(3); |
| |
| if (auto lastHyphen = body.reverseFind('-'); lastHyphen != notFound) { |
| if (auto index = parseInteger<unsigned>(body.substring(lastHyphen + 1)); index >= 1) { |
| auto property = cssPropertyID(body.left(lastHyphen)); |
| if (property == CSSPropertyInvalid) |
| return { }; |
| return { CSSCalc::Random::Key::PropertyIndexScoped { CSSCalc::RandomScopedProperty { property, nullAtom() }, *index - 1 } }; |
| } |
| } |
| |
| auto property = cssPropertyID(body); |
| if (property == CSSPropertyInvalid) |
| return { }; |
| return { CSSCalc::Random::Key::PropertyScoped { CSSCalc::RandomScopedProperty { property, nullAtom() } } }; |
| } |
| |
| std::optional<CSSCalc::Random::Sharing> consumeUnresolvedRandomKey(CSSParserTokenRange& tokens, CSS::PropertyParserState& state, const RandomKeySource& source, NOESCAPE const Function<unsigned()>& consumeIndex) |
| { |
| // <random-key> = auto | <random-cache-key> | fixed <number [0,1]> |
| // <random-cache-key> = <dashed-ident> || element-scoped || [ property-scoped | property-index-scoped | <random-ua-ident> ] |
| |
| if (tokens.peek().id() == CSSValueFixed) { |
| CSSParserTokenRangeGuard guard { tokens }; |
| |
| tokens.consumeIncludingWhitespace(); |
| |
| // Use a non-property parsing state for the fixed number value to disconnect it from the current parse. |
| // FIXME: Add a mechanism to pass along the depth count when doing this so that we can limit stack usage. |
| // FIXME: This should probably maintain the `cssRandomFunctionCount` state from the current state to allow for random() functions nested in the <number> or should document why this is not necessary. |
| auto numberParsingState = CSS::PropertyParserState { |
| .context = state.context, |
| .pool = state.pool, |
| .absoluteLengthUnitsOnly = state.absoluteLengthUnitsOnly |
| }; |
| |
| auto number = MetaConsumer<CSS::Number<CSS::ClosedUnitRange>>::consume(tokens, numberParsingState); |
| if (!number) |
| return { }; |
| |
| guard.commit(); |
| |
| return CSSCalc::Random::Sharing { CSSCalc::Random::SharingFixed { .value = WTF::move(*number) } }; |
| } |
| |
| // `auto` is a standalone <random-key> alternative (its scoping is chosen by the caller); it does not |
| // combine with the <random-cache-key> keywords, so it is handled before the || loop below. |
| if (tokens.peek().id() == CSSValueAuto) { |
| tokens.consumeIncludingWhitespace(); |
| return CSSCalc::Random::Sharing { randomSharingAuto(source, consumeIndex()) }; |
| } |
| |
| CSSCalc::Random::Key key; |
| |
| CSSParserTokenRangeGuard guard { tokens }; |
| |
| auto consumeName = [&] -> bool { |
| if (key.name) |
| return false; |
| if (auto dashedIdent = consumeUnresolvedDashedIdent(tokens, state)) { |
| key.name = WTF::move(*dashedIdent); |
| return true; |
| } |
| return false; |
| }; |
| auto consumeElementScoped = [&] -> bool { |
| if (key.elementScoped) |
| return false; |
| if (tokens.peek().id() == CSSValueElementScoped) { |
| tokens.consumeIncludingWhitespace(); |
| key.elementScoped = CSS::Keyword::ElementScoped { }; |
| return true; |
| } |
| return false; |
| }; |
| // property-scoped and property-index-scoped are mutually exclusive, so a single lambda handles both. |
| auto consumeProperty = [&] -> bool { |
| if (key.propertyScoped) |
| return false; |
| if (tokens.peek().id() == CSSValuePropertyScoped) { |
| tokens.consumeIncludingWhitespace(); |
| // No index is consumed: property-scoped keys on the property alone, and taking an index here |
| // would shift the index of any later `auto` or property-index-scoped in the same value. |
| key.propertyScoped = CSSCalc::Random::Key::PropertyScoped { source.property }; |
| return true; |
| } |
| if (tokens.peek().id() == CSSValuePropertyIndexScoped) { |
| tokens.consumeIncludingWhitespace(); |
| key.propertyScoped = CSSCalc::Random::Key::PropertyIndexScoped { source.property, consumeIndex() }; |
| return true; |
| } |
| // <random-ua-ident> = <custom-ident> starting with `ua-`. It spells out the property, and |
| // optionally the index, that the keywords derive implicitly, so `ua-height-1` names the same |
| // key as property-index-scoped does while parsing `height`. The index is 1-based in the ident. |
| // No index is consumed from the caller: the ident says which one it means. |
| if (tokens.peek().type() == IdentToken) { |
| if (auto identValue = tokens.peek().value(); startsWithLettersIgnoringASCIICase(identValue, "ua-"_s)) { |
| if (auto scoped = parseRandomUAIdent(identValue)) { |
| tokens.consumeIncludingWhitespace(); |
| key.propertyScoped = WTF::move(*scoped); |
| return true; |
| } |
| return false; |
| } |
| } |
| return false; |
| }; |
| |
| for (unsigned i = 0; i < 3; ++i) { |
| if (consumeName() || consumeElementScoped() || consumeProperty()) |
| continue; |
| break; |
| } |
| |
| if (!key.name && !key.elementScoped && !key.propertyScoped) |
| return { }; |
| |
| guard.commit(); |
| |
| return CSSCalc::Random::Sharing { WTF::move(key) }; |
| } |
| |
| CSSCalc::RandomSharingAuto randomSharingAuto(const RandomKeySource& source, unsigned index) |
| { |
| return { |
| .property = source.property, |
| .index = index, |
| .elementScoped = source.autoElementScoped |
| }; |
| } |
| |
| } // namespace CSSPropertyParserHelpers |
| } // namespace WebCore |
