Merge pull request #382 from tayloraswift/desugar-static-self

desugar static Self type tokens when computing autographs

Author: tayloraswift

Scripts/Linux/GenerateTestSymbolGraphs

@@ -11,7 +11,8 @@ swift build \
     -Xswiftc -emit-extension-block-symbols \
     -Xswiftc -include-spi-symbols \
     -Xswiftc -skip-inherited-docs \
-    -Xswiftc -pretty-print
+    -Xswiftc -pretty-print \
+    -Xswiftc -swift-version -Xswiftc 6
 
 swift package --package-path TestModules dump-package > TestModules/Package.swift.json
 

Sources/MarkdownPluginSwift/Signatures/Signature.Expanded (ext).swift

@@ -8,6 +8,7 @@ extension Signature.Expanded
         sugarDictionary:Scalar,
         sugarArray:Scalar,
         sugarOptional:Scalar,
+        desugarSelf:String? = nil,
         landmarks:inout SignatureLandmarks)
     {
         var utf8:[UInt8] = []
@@ -29,7 +30,8 @@ extension Signature.Expanded
             }
         }
 
-        let sugarMap:SignatureSyntax.SugarMap = linkTargets.reduce(into: .init())
+        let sugarMap:SignatureSyntax.SugarMap = linkTargets.reduce(
+            into: .init(staticSelf: desugarSelf))
         {
             switch $1.value
             {
@@ -84,7 +86,7 @@ extension Signature.Expanded
 
     @inlinable
     init(utf8:[UInt8],
-        sugarMap:SignatureSyntax.SugarMap = .init(),
+        sugarMap:SignatureSyntax.SugarMap = .init(staticSelf: nil),
         linkBoundaries:borrowing [Int],
         linkTargets:inout [Int: Scalar],
         landmarks:inout SignatureLandmarks)

Sources/MarkdownPluginSwift/Signatures/SignatureSyntax.Autographer.swift

@@ -215,7 +215,10 @@ extension SignatureSyntax.Autographer
         }
         else if name.text == "`Self`"
         {
-            self.autograph.append("Self")
+            /// This is serendipitously safe because if `Self` is dynamic or has been shadowed
+            /// by a generic parameter, it will appear without the enclosing backticks, even if
+            /// the original source code included unnecessary backticks.
+            self.autograph.append(self.sugarMap.staticSelf ?? "Self")
             return
         }
 

Sources/MarkdownPluginSwift/Signatures/SignatureSyntax.SugarMap.swift

@@ -3,6 +3,15 @@ extension SignatureSyntax
     @frozen @usableFromInline
     struct SugarMap
     {
+        /// The value that will be substituted for residual `` `Self` `` tokens when generating
+        /// autographs.
+        ///
+        /// This exists to correct for an
+        /// [upstream bug in the Swift compiler](https://github.com/swiftlang/swift/issues/78343),
+        /// and does not affect human-visible signature fragments.
+        @usableFromInline
+        let staticSelf:String?
+
         @usableFromInline
         var dictionaries:Set<Int>
         @usableFromInline
@@ -11,8 +20,9 @@ extension SignatureSyntax
         var optionals:Set<Int>
 
         @inlinable
-        init()
+        init(staticSelf:String?)
         {
+            self.staticSelf = staticSelf
             self.dictionaries = []
             self.arrays = []
             self.optionals = []

Sources/MarkdownPluginSwiftTests/Autographs.swift

@@ -192,4 +192,25 @@ struct Autographs
         #expect(self.landmarks.inputs == ["[T]", "[U:V].Type"])
         #expect(self.landmarks.output == ["V?"])
     }
+
+    @Test mutating
+    func DesugaringStaticSelf()
+    {
+        let _:Signature<Symbol.Decl>.Expanded = .init([
+                "func a(_: `Self`, _: [(`Self`)]) -> `Self`?"
+            ],
+            sugarDictionary: .sSD,
+            sugarArray: .sSa,
+            sugarOptional: .sSq,
+            desugarSelf: "DesugaredSelf<A,B>.NestedType",
+            landmarks: &self.landmarks)
+
+        #expect(self.landmarks.inputs == [
+                "DesugaredSelf<A,B>.NestedType",
+                "[DesugaredSelf<A,B>.NestedType]"
+            ])
+        #expect(self.landmarks.output == [
+                "DesugaredSelf<A,B>.NestedType?"
+            ])
+    }
 }

Sources/SymbolGraphParts/Generics/GenericConstraint (ext).swift renamed to Sources/SymbolGraphParts/GenericConstraint (ext).swift

@@ -0,0 +1,31 @@
+import JSONDecoding
+import Signatures
+
+struct GenericParameterWithPosition
+{
+    let depth:UInt
+    let index:Int
+    let name:String
+}
+extension GenericParameterWithPosition
+{
+    var parameter:GenericParameter { .init(name: self.name, depth: self.depth) }
+    var position:(UInt, Int) { (self.depth, self.index) }
+}
+extension GenericParameterWithPosition:JSONObjectDecodable
+{
+    enum CodingKey:String, Sendable
+    {
+        case name
+        case depth
+        case index
+    }
+
+    init(json:JSON.ObjectDecoder<CodingKey>) throws
+    {
+        self.init(
+            depth: try json[.depth].decode(),
+            index: try json[.index].decode(),
+            name: try json[.name].decode())
+    }
+}