This is our first statement attribute, made more complicated by the
fact that a 'case'/'default' isn't really a normal statement. I've
chosen /not/ to implement a general statement attribute logic like we
have for types and decls at this time, but I did get the compiler
parsing arbitrary attributes before 'case' and 'default'. As a bonus,
we now treat all cases within functions as being switch-like rather
than enum-like, which is better for recovery when not in a switch.
Swift syntax APIs lack an abstract way of accessing children. The client has to
down-cast a syntax node to the leaf type to access any of its children. However,
some children are common among different syntax kinds, e.g.
DeclAttributeSyntax and DeclMembers. We should allow an abstract way to
access and modify them, so that clients can avoid logic duplication.
This patch adds a mechanism to define new traits and specify satisfied
traits in specific syntax nodes. A trait is a set of common children
and implemented in Swift as a protocol for syntax nodes to conform to.
As a proof-of-concept, we added two traits for now including DeclGroupSyntax
and BracedSyntax.
Resolves: SR-6931 and SR-6916
* Create Swift libSyntax API
This patch is an initial implementation of the Swift libSyntax API. It
aims to provide all features of the C++ API but exposed to Swift.
It currently resides in SwiftExperimental and will likely exist in a
molten state for a while.
* Only build SwiftSyntax on macOS
* Generate libSyntax API
This patch removes the hand-rolled libSyntax API and replaces it with an
API that's entirely automatically generated. This means the API is
guaranteed to be internally stylistically and functionally consistent.
