[5.9][Macros] Allow keywords after # in freestanding macro expansions
#66703
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Allow keywords after `#` in freestanding macro expansions There is no reason why we shouldn’t allow keywords here. I also thought about allowing keywords after `@` but things become tricky here for two reasons: - In the parser, we parse a type after the `@`, which could start with a keyword itself (e.g. `any`). If we want to keep the parser logic to parse a type after `@` (which I think we should), then it becomes unclear what `@any T` should parse as. - We allow a space between `@` and the type name. This makes it very hard for recovery to tell whether `@ struct` refers to an attribute with name `struct` or if the user forgot to write the attribute name after `@`. Since almost all keywords are lowercase and attached member macros are usually spelled with an uppercase name, there are a lot fewer chances for clashes here, so I don’t think it’s worth allowing keywords after `@`. swiftlang#66444 rdar://110472060
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@swift-ci Please test |
DougGregor
approved these changes
Jun 19, 2023
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#.##casecannot be used, unescaped, as expression macro names #66444 rdar://110472060#in freestanding macro expansions swift-syntax#1778See swiftlang/swift-syntax#1802