[Sema] Support additional args in @dynamicMemberLookup subscripts #81148
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Adds support for satisfying `@dynamicMemberLookup` requirements using subscripts which have arguments following `dynamicMember:` so long as they are either variadic or have default arguments. This allows transforming member references into `x[dynamicMember:...]` calls which can pass in arguments such as `#function`, `#fileID`, `#line`, etc.
| /// a default value | ||
| /// | ||
| /// Subscripts which don't meet these requirements strictly are not eligible. | ||
| enum class DynamicMemberLookupSubscriptEligibility : uint8_t { |
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DynamicMemberLookupSubscriptEligibility is... a mouthful — but it's the least-inaccurate name I could come up with. Happy to improve this with suggestions!
| DynamicMemberLookupSubscriptEligibility | ||
| getDynamicMemberLookupSubscriptEligibility(); |
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Instead of exposing this enum, I suppose it is also possible to restore isValidDynamicMemberLookupSubscript() et. al., but I do think it's nicer to have a type-safe interface that's harder to typo.
| // If bindings were substituted, we need to find the "original" (or | ||
| // contextless) parameter index for the default argument. | ||
| if (shouldSubstituteParameterBindings(subscript)) { | ||
| auto *paramList = SD->getParameterList(); | ||
| assert(paramList); | ||
| paramIdx = paramList->getOrigParamIndex( | ||
| subscript.getSubstitutions(), paramIdx); | ||
| } | ||
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| auto owner = getDefaultArgOwner(subscript, paramIdx); | ||
| auto paramTy = params[paramIdx].getParameterType(); | ||
| argExpr = new (ctx) | ||
| DefaultArgumentExpr(owner, paramIdx, componentLoc, paramTy, dc); |
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This is pretty much what happens in coerceCallArguments, but trying to DRY this out didn't end up feeling worth it.
| // to validate the conformance of the `dynamicMember:` argument to | ||
| // `ExpressibleByStringLiteral`. | ||
| static DynamicMemberLookupSubscriptEligibility | ||
| evaluateDynamicMemberLookupEligibility(const SubscriptDecl *SD, |
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This is the core of what was previously isValidKeyPathDynamicMemberLookup and isValidStringDynamicMemberLookup, factored out
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@swift-ci please smoke test |
Adds support for satisfying
@dynamicMemberLookuprequirements using subscripts which have arguments followingdynamicMember:so long as they are either variadic or have default arguments. This allows transforming member references intox[dynamicMember:...]calls which can pass in arguments such as#function,#fileID,#line, etc.@dynamicMemberLookupSubscripts swift-evolution#2814Main changes:
SubscriptDecls to satisfy@dynamicMemberLookuprequirements as long asdynamicMember:remains the first explicitly-labeled argument, and all following arguments are eitherisDefaultArgument()orisVariadic()SubscriptDecl.Bits; this was being checked multiple times per decl and it seems prudent to just store the info since we have the bitsExprRewriterto produceArgumentLists for these subscripts by filling inDefaultArgumentExprs as neededChanges needed: