diff --git a/lib/ASTGen/.swift-format b/lib/ASTGen/.swift-format
new file mode 100644
index 0000000000000..22b48e0903d5e
--- /dev/null
+++ b/lib/ASTGen/.swift-format
@@ -0,0 +1,17 @@
+{
+    "version": 1,
+    "lineLength": 120,
+    "indentation": {
+        "spaces": 2
+    },
+    "lineBreakBeforeEachArgument": true,
+    "indentConditionalCompilationBlocks": false,
+    "rules": {
+        "AlwaysUseLowerCamelCase": false,
+        "AmbiguousTrailingClosureOverload": false,
+        "NoBlockComments": false,
+        "OrderedImports": true,
+        "UseLetInEveryBoundCaseVariable": false,
+        "UseSynthesizedInitializer": false
+    }
+}
diff --git a/lib/ASTGen/Package.swift b/lib/ASTGen/Package.swift
index 151ea07f960ba..077520beb288d 100644
--- a/lib/ASTGen/Package.swift
+++ b/lib/ASTGen/Package.swift
@@ -42,7 +42,7 @@ let package = Package(
         .product(name: "SwiftSyntaxBuilder", package: "swift-syntax"),
         .product(name: "SwiftSyntaxMacros", package: "swift-syntax"),
         .product(name: "SwiftSyntaxMacroExpansion", package: "swift-syntax"),
-        "swiftLLVMJSON"
+        "swiftLLVMJSON",
       ],
       path: "Sources/ASTGen",
       swiftSettings: swiftSetttings
diff --git a/lib/ASTGen/Sources/ASTGen/ASTGen.swift b/lib/ASTGen/Sources/ASTGen/ASTGen.swift
index 8a9623d6172a0..8e729fe9e0699 100644
--- a/lib/ASTGen/Sources/ASTGen/ASTGen.swift
+++ b/lib/ASTGen/Sources/ASTGen/ASTGen.swift
@@ -1,9 +1,8 @@
 import CASTBridging
 import CBasicBridging
-
 // Needed to use BumpPtrAllocator
-@_spi(BumpPtrAllocator)
-import SwiftSyntax
+@_spi(BumpPtrAllocator) import SwiftSyntax
+
 import struct SwiftDiagnostics.Diagnostic
 
 extension UnsafePointer {
@@ -107,13 +106,19 @@ struct ASTGenVisitor {
         out.append(d.raw)
       case .stmt(let s):
         let topLevelDecl = BridgedTopLevelCodeDecl.createParsed(
-          self.ctx, declContext: self.declContext, startLoc: loc, stmt: s, 
+          self.ctx,
+          declContext: self.declContext,
+          startLoc: loc,
+          stmt: s,
           endLoc: loc
         )
         out.append(topLevelDecl.raw)
       case .expr(let e):
         let topLevelDecl = BridgedTopLevelCodeDecl.createParsed(
-          self.ctx, declContext: self.declContext, startLoc: loc, expr: e,
+          self.ctx,
+          declContext: self.declContext,
+          startLoc: loc,
+          expr: e,
           endLoc: loc
         )
         out.append(topLevelDecl.raw)
@@ -174,7 +179,7 @@ extension ASTGenVisitor {
   func generate(_ node: some SyntaxChildChoices) -> ASTNode {
     return self.generate(Syntax(node))
   }
-    
+
   func generate(_ node: Syntax) -> ASTNode {
     switch node.as(SyntaxEnum.self) {
     case .actorDecl(let node):
diff --git a/lib/ASTGen/Sources/ASTGen/Bridge.swift b/lib/ASTGen/Sources/ASTGen/Bridge.swift
index 5710f6c029668..ef9ce9045d270 100644
--- a/lib/ASTGen/Sources/ASTGen/Bridge.swift
+++ b/lib/ASTGen/Sources/ASTGen/Bridge.swift
@@ -90,7 +90,7 @@ extension Optional where Wrapped: SyntaxProtocol {
     guard let self else {
       return nil
     }
-    
+
     return self.bridgedSourceLoc(in: astgen)
   }
 }
diff --git a/lib/ASTGen/Sources/ASTGen/Decls.swift b/lib/ASTGen/Sources/ASTGen/Decls.swift
index f4070f69ea85a..c7404074b1c6d 100644
--- a/lib/ASTGen/Sources/ASTGen/Decls.swift
+++ b/lib/ASTGen/Sources/ASTGen/Decls.swift
@@ -1,8 +1,6 @@
 import CASTBridging
-
-@_spi(ExperimentalLanguageFeatures)
-import SwiftSyntax
 import SwiftDiagnostics
+@_spi(ExperimentalLanguageFeatures) import SwiftSyntax
 
 // MARK: - TypeDecl
 
@@ -37,7 +35,7 @@ extension ASTGenVisitor {
       genericWhereClause: self.generate(node.genericWhereClause),
       braceRange: BridgedSourceRange(
         startToken: node.memberBlock.leftBrace,
-        endToken: node.memberBlock.rightBrace, 
+        endToken: node.memberBlock.rightBrace,
         in: self
       )
     )
@@ -63,7 +61,7 @@ extension ASTGenVisitor {
       genericWhereClause: self.generate(node.genericWhereClause),
       braceRange: BridgedSourceRange(
         startToken: node.memberBlock.leftBrace,
-        endToken: node.memberBlock.rightBrace, 
+        endToken: node.memberBlock.rightBrace,
         in: self
       )
     )
@@ -339,14 +337,17 @@ extension BridgedOperatorFixity {
 extension ASTGenVisitor {
   func generate(_ node: OperatorDeclSyntax) -> BridgedOperatorDecl {
     let (name, nameLoc) = node.name.bridgedIdentifierAndSourceLoc(in: self)
-    let (precedenceGroupName, precedenceGroupLoc) = (node.operatorPrecedenceAndTypes?.precedenceGroup).bridgedIdentifierAndSourceLoc(in: self)
+    let (precedenceGroupName, precedenceGroupLoc) = (node.operatorPrecedenceAndTypes?.precedenceGroup)
+      .bridgedIdentifierAndSourceLoc(in: self)
 
     let fixity: BridgedOperatorFixity
     if let value = BridgedOperatorFixity(from: node.fixitySpecifier.tokenKind) {
       fixity = value
     } else {
       fixity = .infix
-      self.diagnose(Diagnostic(node: node.fixitySpecifier, message: UnexpectedTokenKindError(token: node.fixitySpecifier)))
+      self.diagnose(
+        Diagnostic(node: node.fixitySpecifier, message: UnexpectedTokenKindError(token: node.fixitySpecifier))
+      )
     }
 
     return .createParsed(
@@ -388,7 +389,9 @@ extension ASTGenVisitor {
     }
 
     func diagnoseDuplicateSyntax(_ duplicate: some SyntaxProtocol, original: some SyntaxProtocol) {
-      self.diagnose(Diagnostic(node: duplicate, message: DuplicateSyntaxError(duplicate: duplicate, original: original)))
+      self.diagnose(
+        Diagnostic(node: duplicate, message: DuplicateSyntaxError(duplicate: duplicate, original: original))
+      )
     }
 
     let body = node.groupAttributes.reduce(into: PrecedenceGroupBody()) { body, element in
diff --git a/lib/ASTGen/Sources/ASTGen/Diagnostics.swift b/lib/ASTGen/Sources/ASTGen/Diagnostics.swift
index 23b65e9d4b746..71923e70bc8a8 100644
--- a/lib/ASTGen/Sources/ASTGen/Diagnostics.swift
+++ b/lib/ASTGen/Sources/ASTGen/Diagnostics.swift
@@ -76,7 +76,9 @@ struct DuplicateSyntaxError: ASTGenError {
   init(duplicate: some SyntaxProtocol, original: some SyntaxProtocol) {
     precondition(duplicate.kind == original.kind, "Expected duplicate and original to be of same kind")
 
-    guard let duplicateParent = duplicate.parent, let originalParent = original.parent, duplicateParent == originalParent, duplicateParent.kind.isSyntaxCollection else {
+    guard let duplicateParent = duplicate.parent, let originalParent = original.parent,
+      duplicateParent == originalParent, duplicateParent.kind.isSyntaxCollection
+    else {
       preconditionFailure("Expected a shared syntax collection parent")
     }
 
diff --git a/lib/ASTGen/Sources/ASTGen/DiagnosticsBridge.swift b/lib/ASTGen/Sources/ASTGen/DiagnosticsBridge.swift
index b6be1098b39df..7b31ef0da8cf9 100644
--- a/lib/ASTGen/Sources/ASTGen/DiagnosticsBridge.swift
+++ b/lib/ASTGen/Sources/ASTGen/DiagnosticsBridge.swift
@@ -52,7 +52,8 @@ fileprivate func emitDiagnosticParts(
     case .replaceLeadingTrivia(let oldToken, let newTrivia):
       replaceStartLoc = bridgedSourceLoc(at: oldToken.position)
       replaceEndLoc = bridgedSourceLoc(
-        at: oldToken.positionAfterSkippingLeadingTrivia)
+        at: oldToken.positionAfterSkippingLeadingTrivia
+      )
       newText = newTrivia.description
 
     case .replaceTrailingTrivia(let oldToken, let newTrivia):
@@ -63,7 +64,8 @@ fileprivate func emitDiagnosticParts(
 
     newText.withBridgedString { bridgedMessage in
       diag.fixItReplace(
-        start: replaceStartLoc, end: replaceEndLoc,
+        start: replaceStartLoc,
+        end: replaceEndLoc,
         replacement: bridgedMessage
       )
     }
@@ -117,11 +119,11 @@ func emitDiagnostic(
 extension DiagnosticSeverity {
   var bridged: BridgedDiagnosticSeverity {
     switch self {
-      case .error: return .error
-      case .note: return .note
-      case .warning: return .warning
-      case .remark: return .remark
-      @unknown default: return .error
+    case .error: return .error
+    case .note: return .note
+    case .warning: return .warning
+    case .remark: return .remark
+    @unknown default: return .error
     }
   }
 }
@@ -186,7 +188,8 @@ extension SourceManager {
       case .replaceTrailingTrivia(let oldToken, let newTrivia):
         replaceStartLoc = bridgedSourceLoc(
           for: oldToken,
-          at: oldToken.endPositionBeforeTrailingTrivia)
+          at: oldToken.endPositionBeforeTrailingTrivia
+        )
         replaceEndLoc = bridgedSourceLoc(
           for: oldToken,
           at: oldToken.endPosition
@@ -196,7 +199,8 @@ extension SourceManager {
 
       newText.withBridgedString { bridgedMessage in
         diag.fixItReplace(
-          start: replaceStartLoc, end: replaceEndLoc,
+          start: replaceStartLoc,
+          end: replaceEndLoc,
           replacement: bridgedMessage
         )
       }
@@ -222,11 +226,11 @@ extension SourceManager {
     // Emit Fix-Its.
     for fixIt in diagnostic.fixIts {
       diagnoseSingle(
-          message: fixIt.message.message,
-          severity: .note,
-          node: diagnostic.node,
-          position: diagnostic.position,
-          fixItChanges: fixIt.changes
+        message: fixIt.message.message,
+        severity: .note,
+        node: diagnostic.node,
+        position: diagnostic.position,
+        fixItChanges: fixIt.changes
       )
     }
 
@@ -315,7 +319,8 @@ public func addQueuedSourceFile(
   // Determine the parent link, for a child buffer.
   let parent: (GroupedDiagnostics.SourceFileID, AbsolutePosition)?
   if parentID >= 0,
-      let parentSourceFileID = queuedDiagnostics.pointee.sourceFileIDs[parentID] {
+    let parentSourceFileID = queuedDiagnostics.pointee.sourceFileIDs[parentID]
+  {
     parent = (parentSourceFileID.pointee, AbsolutePosition(utf8Offset: positionInParent))
   } else {
     parent = nil
@@ -387,17 +392,20 @@ public func addQueuedDiagnostic(
   // Map the highlights.
   var highlights: [Syntax] = []
   let highlightRanges = UnsafeBufferPointer<BridgedSourceLoc>(
-    start: highlightRangesPtr, count: numHighlightRanges * 2
+    start: highlightRangesPtr,
+    count: numHighlightRanges * 2
   )
   for index in 0..<numHighlightRanges {
     // Make sure both the start and the end land within this source file.
     guard let start = highlightRanges[index * 2].raw,
-          let end = highlightRanges[index * 2 + 1].raw  else {
+      let end = highlightRanges[index * 2 + 1].raw
+    else {
       continue
     }
 
     guard start >= sourceFileBaseAddress && start < sourceFileEndAddress,
-          end >= sourceFileBaseAddress && end <= sourceFileEndAddress else {
+      end >= sourceFileBaseAddress && end <= sourceFileEndAddress
+    else {
       continue
     }
 
@@ -414,8 +422,9 @@ public func addQueuedDiagnostic(
     while true {
       // If this syntax matches our starting/ending positions, add the
       // highlight and we're done.
-      if highlightSyntax.positionAfterSkippingLeadingTrivia == startPos &&
-          highlightSyntax.endPositionBeforeTrailingTrivia == endPos {
+      if highlightSyntax.positionAfterSkippingLeadingTrivia == startPos
+        && highlightSyntax.endPositionBeforeTrailingTrivia == endPos
+      {
         highlights.append(highlightSyntax)
         break
       }
diff --git a/lib/ASTGen/Sources/ASTGen/Exprs.swift b/lib/ASTGen/Sources/ASTGen/Exprs.swift
index 1ad6f101c24de..ceaf263705451 100644
--- a/lib/ASTGen/Sources/ASTGen/Exprs.swift
+++ b/lib/ASTGen/Sources/ASTGen/Exprs.swift
@@ -1,6 +1,6 @@
 import CASTBridging
-import SwiftSyntax
 import SwiftDiagnostics
+import SwiftSyntax
 
 extension ASTGenVisitor {
   public func generate(_ node: ClosureExprSyntax) -> BridgedClosureExpr {
@@ -18,10 +18,14 @@ extension ASTGenVisitor {
   public func generate(_ node: FunctionCallExprSyntax) -> BridgedCallExpr {
     if !node.arguments.isEmpty || node.trailingClosure == nil {
       if node.leftParen == nil {
-        self.diagnose(Diagnostic(node: node, message: MissingChildTokenError(parent: node, kindOfTokenMissing: .leftParen)))
+        self.diagnose(
+          Diagnostic(node: node, message: MissingChildTokenError(parent: node, kindOfTokenMissing: .leftParen))
+        )
       }
       if node.rightParen == nil {
-        self.diagnose(Diagnostic(node: node, message: MissingChildTokenError(parent: node, kindOfTokenMissing: .rightParen)))
+        self.diagnose(
+          Diagnostic(node: node, message: MissingChildTokenError(parent: node, kindOfTokenMissing: .rightParen))
+        )
       }
     }
 
@@ -30,14 +34,20 @@ extension ASTGenVisitor {
     // Transform the trailing closure into an argument.
     if let trailingClosure = node.trailingClosure {
       let tupleElement = LabeledExprSyntax(
-        label: nil, colon: nil, expression: ExprSyntax(trailingClosure), trailingComma: nil)
+        label: nil,
+        colon: nil,
+        expression: ExprSyntax(trailingClosure),
+        trailingComma: nil
+      )
 
       node.arguments.append(tupleElement)
       node.trailingClosure = nil
     }
 
     let argumentTuple = self.generate(
-      node.arguments, leftParen: node.leftParen, rightParen: node.rightParen
+      node.arguments,
+      leftParen: node.leftParen,
+      rightParen: node.rightParen
     )
     let callee = generate(node.calledExpression)
 
@@ -69,7 +79,10 @@ extension ASTGenVisitor {
 
     // Wrap in a SingleValueStmtExpr to embed as an expression.
     return .createWithWrappedBranches(
-      ctx, stmt: stmt, declContext: declContext, mustBeExpr: true
+      ctx,
+      stmt: stmt,
+      declContext: declContext,
+      mustBeExpr: true
     )
   }
 
@@ -94,7 +107,7 @@ extension ASTGenVisitor {
 
       return $0.bridgedSourceLoc(in: self)
     }
-    
+
     return BridgedTupleExpr.createParsed(
       self.ctx,
       leftParenLoc: leftParen.bridgedSourceLoc(in: self),
diff --git a/lib/ASTGen/Sources/ASTGen/Macros.swift b/lib/ASTGen/Sources/ASTGen/Macros.swift
index 4b82f8e855fe5..9de21f6580aa3 100644
--- a/lib/ASTGen/Sources/ASTGen/Macros.swift
+++ b/lib/ASTGen/Sources/ASTGen/Macros.swift
@@ -11,13 +11,13 @@
 //===----------------------------------------------------------------------===//
 
 import CASTBridging
+import SwiftCompilerPluginMessageHandling
 import SwiftDiagnostics
 import SwiftOperators
+import SwiftSyntax
 import SwiftSyntaxBuilder
-import SwiftSyntaxMacros
 import SwiftSyntaxMacroExpansion
-import SwiftCompilerPluginMessageHandling
-import SwiftSyntax
+import SwiftSyntaxMacros
 
 extension SyntaxProtocol {
   func token(at position: AbsolutePosition) -> TokenSyntax? {
@@ -118,10 +118,13 @@ public func resolveExecutableMacro(
   // Executable plugins is "trusted" to have the macro implementation. If not,
   // the actual expansion fails.
   let exportedPtr = UnsafeMutablePointer<ExportedExecutableMacro>.allocate(capacity: 1)
-  exportedPtr.initialize(to: .init(
-    moduleName: String(cString: moduleName),
-    typeName: String(cString: typeName),
-    plugin: CompilerPlugin(opaqueHandle: pluginOpaqueHandle)))
+  exportedPtr.initialize(
+    to: .init(
+      moduleName: String(cString: moduleName),
+      typeName: String(cString: typeName),
+      plugin: CompilerPlugin(opaqueHandle: pluginOpaqueHandle)
+    )
+  )
   return UnsafeRawPointer(exportedPtr)
 }
 
@@ -189,9 +192,10 @@ enum ASTGenMacroDiagnostic: DiagnosticMessage, FixItMessage {
 /// single identifier.
 fileprivate func identifierFromStringLiteral(_ node: ExprSyntax) -> String? {
   guard let stringLiteral = node.as(StringLiteralExprSyntax.self),
-        stringLiteral.segments.count == 1,
-        let segment = stringLiteral.segments.first,
-        case .stringSegment(let stringSegment) = segment else {
+    stringLiteral.segments.count == 1,
+    let segment = stringLiteral.segments.first,
+    case .stringSegment(let stringSegment) = segment
+  else {
     return nil
   }
 
@@ -202,7 +206,7 @@ fileprivate func identifierFromStringLiteral(_ node: ExprSyntax) -> String? {
 /// for use in macro expansion.
 ///
 /// When the resulting macro requires expansion, the result will come in
-/// two parts: 
+/// two parts:
 ///
 /// - Returns: -1 on failure, BridgedMacroDefinitionKind on success. When the
 /// successful result is "expanded macro", `replacementsPtr` will point to a
@@ -214,12 +218,12 @@ fileprivate func identifierFromStringLiteral(_ node: ExprSyntax) -> String? {
 /// argument matching the corresponding parameter.
 @_cdecl("swift_ASTGen_checkMacroDefinition")
 func checkMacroDefinition(
-    diagEnginePtr: UnsafeMutableRawPointer,
-    sourceFilePtr: UnsafeRawPointer,
-    macroLocationPtr: UnsafePointer<UInt8>,
-    externalMacroOutPtr: UnsafeMutablePointer<BridgedString>,
-    replacementsPtr: UnsafeMutablePointer<UnsafeMutablePointer<Int>?>,
-    numReplacementsPtr: UnsafeMutablePointer<Int>
+  diagEnginePtr: UnsafeMutableRawPointer,
+  sourceFilePtr: UnsafeRawPointer,
+  macroLocationPtr: UnsafePointer<UInt8>,
+  externalMacroOutPtr: UnsafeMutablePointer<BridgedString>,
+  replacementsPtr: UnsafeMutablePointer<UnsafeMutablePointer<Int>?>,
+  numReplacementsPtr: UnsafeMutablePointer<Int>
 ) -> Int {
   // Assert "out" parameters are initialized.
   assert(externalMacroOutPtr.pointee.isEmptyInitialized)
@@ -228,11 +232,13 @@ func checkMacroDefinition(
   let sourceFilePtr = sourceFilePtr.bindMemory(to: ExportedSourceFile.self, capacity: 1)
 
   // Find the macro declaration.
-  guard let macroDecl = findSyntaxNodeInSourceFile(
-    sourceFilePtr: sourceFilePtr,
-    sourceLocationPtr: macroLocationPtr,
-    type: MacroDeclSyntax.self
-  ) else {
+  guard
+    let macroDecl = findSyntaxNodeInSourceFile(
+      sourceFilePtr: sourceFilePtr,
+      sourceLocationPtr: macroLocationPtr,
+      type: MacroDeclSyntax.self
+    )
+  else {
     // FIXME: Produce an error
     return -1
   }
@@ -294,12 +300,13 @@ func checkMacroDefinition(
       return Int(BridgedMacroDefinitionKind.externalMacro.rawValue)
 
     case let .expansion(expansionSyntax, replacements: _)
-        where expansionSyntax.macroName.text == "externalMacro":
+    where expansionSyntax.macroName.text == "externalMacro":
       // Extract the identifier from the "module" argument.
       guard let firstArg = expansionSyntax.arguments.first,
-            let firstArgLabel = firstArg.label?.text,
-            firstArgLabel == "module",
-            let module = identifierFromStringLiteral(firstArg.expression) else {
+        let firstArgLabel = firstArg.label?.text,
+        firstArgLabel == "module",
+        let module = identifierFromStringLiteral(firstArg.expression)
+      else {
         let srcMgr = SourceManager(cxxDiagnosticEngine: diagEnginePtr)
         srcMgr.insert(sourceFilePtr)
         srcMgr.diagnose(
@@ -313,9 +320,10 @@ func checkMacroDefinition(
 
       // Extract the identifier from the "type" argument.
       guard let secondArg = expansionSyntax.arguments.dropFirst().first,
-            let secondArgLabel = secondArg.label?.text,
-            secondArgLabel == "type",
-            let type = identifierFromStringLiteral(secondArg.expression) else {
+        let secondArgLabel = secondArg.label?.text,
+        secondArgLabel == "type",
+        let type = identifierFromStringLiteral(secondArg.expression)
+      else {
         let srcMgr = SourceManager(cxxDiagnosticEngine: diagEnginePtr)
         srcMgr.insert(sourceFilePtr)
         srcMgr.diagnose(
@@ -337,7 +345,6 @@ func checkMacroDefinition(
       externalMacroOutPtr.pointee =
         allocateBridgedString(expansionSyntax.trimmedDescription)
 
-
       // If there are no replacements, we're done.
       if replacements.isEmpty {
         return Int(BridgedMacroDefinitionKind.expandedMacro.rawValue)
@@ -348,8 +355,10 @@ func checkMacroDefinition(
       for (index, replacement) in replacements.enumerated() {
         let expansionStart = expansionSyntax.positionAfterSkippingLeadingTrivia.utf8Offset
 
-        replacementBuffer[index * 3] = replacement.reference.positionAfterSkippingLeadingTrivia.utf8Offset - expansionStart
-        replacementBuffer[index * 3 + 1] = replacement.reference.endPositionBeforeTrailingTrivia.utf8Offset - expansionStart
+        replacementBuffer[index * 3] =
+          replacement.reference.positionAfterSkippingLeadingTrivia.utf8Offset - expansionStart
+        replacementBuffer[index * 3 + 1] =
+          replacement.reference.endPositionBeforeTrailingTrivia.utf8Offset - expansionStart
         replacementBuffer[index * 3 + 2] = replacement.parameterIndex
       }
 
@@ -420,18 +429,24 @@ func expandFreestandingMacro(
 
   let sourceFilePtr = sourceFilePtr.bindMemory(to: ExportedSourceFile.self, capacity: 1)
 
-  guard let macroSyntax = findSyntaxNodeInSourceFile(
-    sourceFilePtr: sourceFilePtr, sourceLocationPtr: sourceLocationPtr, type: Syntax.self) else {
+  guard
+    let macroSyntax = findSyntaxNodeInSourceFile(
+      sourceFilePtr: sourceFilePtr,
+      sourceLocationPtr: sourceLocationPtr,
+      type: Syntax.self
+    )
+  else {
     return 1
   }
-  guard let expansion = macroSyntax.asProtocol(
-    FreestandingMacroExpansionSyntax.self
-  ) else {
+  guard
+    let expansion = macroSyntax.asProtocol(
+      FreestandingMacroExpansionSyntax.self
+    )
+  else {
     print("not on a macro expansion node: \(macroSyntax.debugDescription)")
     return 1
   }
 
-
   let discriminator = String(cString: discriminatorText)
 
   let macroRole = MacroRole(rawMacroRole: rawMacroRole)
@@ -444,7 +459,8 @@ func expandFreestandingMacro(
       diagEnginePtr: diagEnginePtr,
       expansionSyntax: expansion,
       sourceFilePtr: sourceFilePtr,
-      discriminator: discriminator)
+      discriminator: discriminator
+    )
   case .Executable:
     expandedSource = expandFreestandingMacroIPC(
       macroPtr: macroPtr,
@@ -452,7 +468,8 @@ func expandFreestandingMacro(
       diagEnginePtr: diagEnginePtr,
       expansionSyntax: expansion,
       sourceFilePtr: sourceFilePtr,
-      discriminator: discriminator)
+      discriminator: discriminator
+    )
   }
 
   return makeExpansionOutputResult(
@@ -497,15 +514,15 @@ func expandFreestandingMacroIPC(
     macro: .init(moduleName: macro.moduleName, typeName: macro.typeName, name: macroName),
     macroRole: pluginMacroRole,
     discriminator: discriminator,
-    syntax: PluginMessage.Syntax(syntax: Syntax(expansionSyntax), in: sourceFilePtr)!)
+    syntax: PluginMessage.Syntax(syntax: Syntax(expansionSyntax), in: sourceFilePtr)!
+  )
   do {
     let result = try macro.plugin.sendMessageAndWait(message)
     let expandedSource: String?
     let diagnostics: [PluginMessage.Diagnostic]
     switch result {
-    case
-        .expandMacroResult(let _expandedSource, let _diagnostics),
-        .expandFreestandingMacroResult(let _expandedSource, let _diagnostics):
+    case .expandMacroResult(let _expandedSource, let _diagnostics),
+      .expandFreestandingMacroResult(let _expandedSource, let _diagnostics):
       expandedSource = _expandedSource
       diagnostics = _diagnostics
     default:
@@ -596,7 +613,8 @@ func findSyntaxNodeInSourceFile<Node: SyntaxProtocol>(
   }
 
   let sourceFilePtr = sourceFilePtr.bindMemory(
-    to: ExportedSourceFile.self, capacity: 1
+    to: ExportedSourceFile.self,
+    capacity: 1
   )
 
   // Find the offset.
@@ -638,14 +656,16 @@ func findSyntaxNodeInSourceFile<Node: SyntaxProtocol>(
     while let parentSyntax = resultSyntax.parent {
       // Look through type compositions.
       if let compositionElement = parentSyntax.as(CompositionTypeElementSyntax.self),
-         let compositionList = compositionElement.parent?.as(CompositionTypeElementListSyntax.self),
-         let typedParent = compositionList.parent?.as(type) {
+        let compositionList = compositionElement.parent?.as(CompositionTypeElementListSyntax.self),
+        let typedParent = compositionList.parent?.as(type)
+      {
         resultSyntax = typedParent
         continue
       }
 
       guard let typedParent = parentSyntax.as(type),
-            typedParent.position == resultSyntax.position else {
+        typedParent.position == resultSyntax.position
+      else {
         break
       }
 
@@ -678,21 +698,25 @@ func expandAttachedMacro(
   assert(expandedSourceOutPtr.pointee.isEmptyInitialized)
 
   // Dig out the custom attribute for the attached macro declarations.
-  guard let customAttrNode = findSyntaxNodeInSourceFile(
-    sourceFilePtr: customAttrSourceFilePtr,
-    sourceLocationPtr: customAttrSourceLocPointer,
-    type: AttributeSyntax.self
-  ) else {
+  guard
+    let customAttrNode = findSyntaxNodeInSourceFile(
+      sourceFilePtr: customAttrSourceFilePtr,
+      sourceLocationPtr: customAttrSourceLocPointer,
+      type: AttributeSyntax.self
+    )
+  else {
     return 1
   }
 
   // Dig out the node for the declaration to which the custom attribute is
   // attached.
-  guard let declarationNode = findSyntaxNodeInSourceFile(
-    sourceFilePtr: declarationSourceFilePtr,
-    sourceLocationPtr: declarationSourceLocPointer,
-    type: DeclSyntax.self
-  ) else {
+  guard
+    let declarationNode = findSyntaxNodeInSourceFile(
+      sourceFilePtr: declarationSourceFilePtr,
+      sourceLocationPtr: declarationSourceLocPointer,
+      type: DeclSyntax.self
+    )
+  else {
     return 1
   }
 
@@ -728,7 +752,8 @@ func expandAttachedMacro(
       declarationSourceFilePtr: declarationSourceFilePtr,
       attachedTo: declarationNode,
       parentDeclSourceFilePtr: parentDeclSourceFilePtr,
-      parentDeclNode: parentDeclNode)
+      parentDeclNode: parentDeclNode
+    )
   case .InProcess:
     expandedSource = expandAttachedMacroInProcess(
       diagEnginePtr: diagEnginePtr,
@@ -742,7 +767,8 @@ func expandAttachedMacro(
       declarationSourceFilePtr: declarationSourceFilePtr,
       attachedTo: declarationNode,
       parentDeclSourceFilePtr: parentDeclSourceFilePtr,
-      parentDeclNode: parentDeclNode)
+      parentDeclNode: parentDeclNode
+    )
   }
 
   return makeExpansionOutputResult(
@@ -777,19 +803,22 @@ func expandAttachedMacroIPC(
   case .peer: macroRole = .peer
   case .conformance: macroRole = .conformance
   case .extension: macroRole = .`extension`
-  case
-      .expression,
-      .declaration,
-      .codeItem:
+  case .expression,
+    .declaration,
+    .codeItem:
     preconditionFailure("unhandled macro role for attached macro")
   }
 
   // Prepare syntax nodes to transfer.
   let customAttributeSyntax = PluginMessage.Syntax(
-    syntax: Syntax(customAttrNode), in: customAttrSourceFilePtr)!
+    syntax: Syntax(customAttrNode),
+    in: customAttrSourceFilePtr
+  )!
 
   let declSyntax = PluginMessage.Syntax(
-    syntax: Syntax(declarationNode), in: customAttrSourceFilePtr)!
+    syntax: Syntax(declarationNode),
+    in: customAttrSourceFilePtr
+  )!
 
   let parentDeclSyntax: PluginMessage.Syntax?
   if parentDeclNode != nil {
@@ -826,7 +855,8 @@ func expandAttachedMacroIPC(
     declSyntax: declSyntax,
     parentDeclSyntax: parentDeclSyntax,
     extendedTypeSyntax: extendedTypeSyntax,
-    conformanceListSyntax: conformanceListSyntax)
+    conformanceListSyntax: conformanceListSyntax
+  )
   do {
     let expandedSource: String?
     let diagnostics: [PluginMessage.Diagnostic]
diff --git a/lib/ASTGen/Sources/ASTGen/PluginHost.swift b/lib/ASTGen/Sources/ASTGen/PluginHost.swift
index 8aab03a268b9b..9ba4546158c0d 100644
--- a/lib/ASTGen/Sources/ASTGen/PluginHost.swift
+++ b/lib/ASTGen/Sources/ASTGen/PluginHost.swift
@@ -12,9 +12,9 @@
 
 import CASTBridging
 import CBasicBridging
+import SwiftCompilerPluginMessageHandling
 import SwiftSyntax
 import swiftLLVMJSON
-import SwiftCompilerPluginMessageHandling
 
 enum PluginError: String, Error, CustomStringConvertible {
   case stalePlugin = "plugin is stale"
@@ -47,7 +47,7 @@ public func _initializePlugin(
 public func _deinitializePlugin(
   opaqueHandle: UnsafeMutableRawPointer
 ) {
-  let plugin =  CompilerPlugin(opaqueHandle: opaqueHandle)
+  let plugin = CompilerPlugin(opaqueHandle: opaqueHandle)
   plugin.deinitialize()
 }
 
@@ -60,7 +60,7 @@ func swift_ASTGen_pluginServerLoadLibraryPlugin(
   moduleName: UnsafePointer<CChar>,
   errorOut: UnsafeMutablePointer<BridgedString>?
 ) -> Bool {
-  let plugin =  CompilerPlugin(opaqueHandle: opaqueHandle)
+  let plugin = CompilerPlugin(opaqueHandle: opaqueHandle)
 
   if plugin.capability?.features.contains(.loadPluginLibrary) != true {
     errorOut?.pointee = allocateBridgedString("compiler plugin not loaded: '\(libraryPath); invalid plugin server")
@@ -81,7 +81,7 @@ func swift_ASTGen_pluginServerLoadLibraryPlugin(
       assert(diagnostics.isEmpty)
       return true
     }
-    var errorMsgs = diagnostics.map({$0.message}).joined(separator: ", ");
+    var errorMsgs = diagnostics.map({ $0.message }).joined(separator: ", ");
     errorOut?.pointee = allocateBridgedString(errorMsgs);
     return false
   } catch {
@@ -234,7 +234,8 @@ class PluginDiagnosticsEngine {
       message: diagnostic.message + (messageSuffix ?? ""),
       severity: diagnostic.severity,
       position: diagnostic.position,
-      highlights: diagnostic.highlights)
+      highlights: diagnostic.highlights
+    )
 
     // Emit Fix-Its.
     for fixIt in diagnostic.fixIts {
@@ -242,7 +243,8 @@ class PluginDiagnosticsEngine {
         message: fixIt.message,
         severity: .note,
         position: diagnostic.position,
-        fixItChanges: fixIt.changes)
+        fixItChanges: fixIt.changes
+      )
     }
 
     // Emit any notes as follow-ons.
@@ -250,7 +252,8 @@ class PluginDiagnosticsEngine {
       emitSingle(
         message: note.message,
         severity: .note,
-        position: note.position)
+        position: note.position
+      )
     }
   }
   /// Emit single C++ diagnostic.
@@ -298,7 +301,10 @@ class PluginDiagnosticsEngine {
       var newText = change.newText
       newText.withBridgedString { bridgedFixItText in
         diag.fixItReplace(
-          start: startLoc, end: endLoc, replacement: bridgedFixItText)
+          start: startLoc,
+          end: endLoc,
+          replacement: bridgedFixItText
+        )
       }
     }
 
@@ -330,7 +336,8 @@ class PluginDiagnosticsEngine {
   /// Produce the C++ source location for a given position based on a
   /// syntax node.
   private func bridgedSourceLoc(
-    at offset: Int, in fileName: String
+    at offset: Int,
+    in fileName: String
   ) -> BridgedSourceLoc {
     // Find the corresponding exported source file.
     guard let exportedSourceFile = exportedSourceFileByName[fileName] else {
@@ -361,7 +368,7 @@ class PluginDiagnosticsEngine {
     if start.raw == nil || end.raw == nil {
       return nil
     }
-    return (start: start, end: end )
+    return (start: start, end: end)
   }
 }
 
@@ -393,7 +400,9 @@ extension PluginMessage.Syntax {
         fileName: fileName,
         offset: loc.offset,
         line: loc.line,
-        column: loc.column))
+        column: loc.column
+      )
+    )
   }
 
   init?(syntax: Syntax) {
diff --git a/lib/ASTGen/Sources/ASTGen/SourceFile.swift b/lib/ASTGen/Sources/ASTGen/SourceFile.swift
index edd4657d0e42b..84e249283f347 100644
--- a/lib/ASTGen/Sources/ASTGen/SourceFile.swift
+++ b/lib/ASTGen/Sources/ASTGen/SourceFile.swift
@@ -1,12 +1,9 @@
-import CBasicBridging
 import CASTBridging
-
+import CBasicBridging
 import SwiftDiagnostics
-import SwiftSyntax
+@_spi(ExperimentalLanguageFeatures) import SwiftParser
 import SwiftParserDiagnostics
-
-@_spi(ExperimentalLanguageFeatures)
-import SwiftParser
+import SwiftSyntax
 
 /// Describes a source file that has been "exported" to the C++ part of the
 /// compiler, with enough information to interface with the C++ layer.
@@ -45,8 +42,10 @@ extension Parser.ExperimentalFeatures {
 /// ExportedSourceFile instance.
 @_cdecl("swift_ASTGen_parseSourceFile")
 public func parseSourceFile(
-  buffer: UnsafePointer<UInt8>, bufferLength: Int,
-  moduleName: UnsafePointer<UInt8>, filename: UnsafePointer<UInt8>,
+  buffer: UnsafePointer<UInt8>,
+  bufferLength: Int,
+  moduleName: UnsafePointer<UInt8>,
+  filename: UnsafePointer<UInt8>,
   ctxPtr: UnsafeMutableRawPointer?
 ) -> UnsafeRawPointer {
   let buffer = UnsafeBufferPointer(start: buffer, count: bufferLength)
@@ -57,8 +56,11 @@ public func parseSourceFile(
   let exportedPtr = UnsafeMutablePointer<ExportedSourceFile>.allocate(capacity: 1)
   exportedPtr.initialize(
     to: .init(
-      buffer: buffer, moduleName: String(cString: moduleName),
-      fileName: String(cString: filename), syntax: sourceFile)
+      buffer: buffer,
+      moduleName: String(cString: moduleName),
+      fileName: String(cString: filename),
+      syntax: sourceFile
+    )
   )
 
   return UnsafeRawPointer(exportedPtr)
@@ -106,7 +108,8 @@ public func emitParserDiagnostics(
   downgradePlaceholderErrorsToWarnings: CInt
 ) -> CInt {
   return sourceFilePtr.withMemoryRebound(
-    to: ExportedSourceFile.self, capacity: 1
+    to: ExportedSourceFile.self,
+    capacity: 1
   ) { sourceFile in
     var anyDiags = false
 
@@ -124,7 +127,9 @@ public func emitParserDiagnostics(
       }
 
       let diagnosticSeverity: DiagnosticSeverity
-      if downgradePlaceholderErrorsToWarnings == 1 && diag.diagMessage.diagnosticID == StaticTokenError.editorPlaceholder.diagnosticID {
+      if downgradePlaceholderErrorsToWarnings == 1
+        && diag.diagMessage.diagnosticID == StaticTokenError.editorPlaceholder.diagnosticID
+      {
         diagnosticSeverity = .warning
       } else {
         diagnosticSeverity = diag.diagMessage.severity
diff --git a/lib/ASTGen/Sources/ASTGen/SourceManager+MacroExpansionContext.swift b/lib/ASTGen/Sources/ASTGen/SourceManager+MacroExpansionContext.swift
index b42fbc6186d7d..88410dfa8bb76 100644
--- a/lib/ASTGen/Sources/ASTGen/SourceManager+MacroExpansionContext.swift
+++ b/lib/ASTGen/Sources/ASTGen/SourceManager+MacroExpansionContext.swift
@@ -34,7 +34,8 @@ extension SourceManager {
     discriminator: String = ""
   ) -> MacroExpansionContext {
     return MacroExpansionContext(
-      sourceManager: self, discriminator: discriminator
+      sourceManager: self,
+      discriminator: discriminator
     )
   }
 }
@@ -43,13 +44,15 @@ extension String {
   /// Retrieve the base name of a string that represents a path, removing the
   /// directory.
   var basename: String {
-    guard let lastSlash = lastIndex(where: {
-#if os(iOS) || os(macOS) || os(tvOS) || os(watchOS) || os(Android) || os(Linux)
+    guard
+      let lastSlash = lastIndex(where: {
+        #if os(iOS) || os(macOS) || os(tvOS) || os(watchOS) || os(Android) || os(Linux)
         ["/"].contains($0)
-#else
+        #else
         ["/", "\\"].contains($0)
-#endif
-    }) else {
+        #endif
+      })
+    else {
       return self
     }
 
@@ -96,8 +99,8 @@ extension SourceManager.MacroExpansionContext: MacroExpansionContext {
     filePathMode: SourceLocationFilePathMode
   ) -> AbstractSourceLocation? {
     guard let (sourceFile, rootPosition) = sourceManager.rootSourceFile(of: node),
-        let exportedSourceFile =
-            sourceManager.exportedSourceFilesBySyntax[sourceFile]?.pointee
+      let exportedSourceFile =
+        sourceManager.exportedSourceFilesBySyntax[sourceFile]?.pointee
     else {
       return nil
     }
diff --git a/lib/ASTGen/Sources/ASTGen/SourceManager.swift b/lib/ASTGen/Sources/ASTGen/SourceManager.swift
index 2af74a95b078c..8d6f4a9b40260 100644
--- a/lib/ASTGen/Sources/ASTGen/SourceManager.swift
+++ b/lib/ASTGen/Sources/ASTGen/SourceManager.swift
@@ -14,9 +14,7 @@ class SourceManager {
 
   /// The set of source files that have been exported to the C++ code of
   /// the program.
-  var exportedSourceFilesBySyntax: [
-    SourceFileSyntax : UnsafePointer<ExportedSourceFile>
-  ] = [:]
+  var exportedSourceFilesBySyntax: [SourceFileSyntax: UnsafePointer<ExportedSourceFile>] = [:]
 
   /// The set of nodes that have been detached from their parent nodes.
   ///
@@ -90,8 +88,8 @@ extension SourceManager {
 
     // The position of our node is...
     let finalPosition =
-      node.position                      // Our position relative to its root
-      + SourceLength(utf8Length: offset) // and that root's offset in its parent
+      node.position  // Our position relative to its root
+      + SourceLength(utf8Length: offset)  // and that root's offset in its parent
       + SourceLength(utf8Length: parentOffset.utf8Offset)
     return (rootSF, finalPosition)
   }
diff --git a/lib/ASTGen/Sources/ASTGen/Types.swift b/lib/ASTGen/Sources/ASTGen/Types.swift
index 72de61e76d7d7..89f386ace69f8 100644
--- a/lib/ASTGen/Sources/ASTGen/Types.swift
+++ b/lib/ASTGen/Sources/ASTGen/Types.swift
@@ -1,8 +1,6 @@
 import CASTBridging
-
-@_spi(ExperimentalLanguageFeatures)
-import SwiftSyntax
 import SwiftDiagnostics
+@_spi(ExperimentalLanguageFeatures) import SwiftSyntax
 
 extension ASTGenVisitor {
   public func generate(_ node: IdentifierTypeSyntax) -> BridgedTypeRepr {
@@ -69,7 +67,9 @@ extension ASTGenVisitor {
     let memberComponents = reverseMemberComponents.reversed().bridgedArray(in: self)
 
     return BridgedMemberTypeRepr.createParsed(
-      self.ctx, base: baseComponent, members: memberComponents
+      self.ctx,
+      base: baseComponent,
+      members: memberComponents
     )
   }
 
@@ -78,7 +78,9 @@ extension ASTGenVisitor {
     let lSquareLoc = node.leftSquare.bridgedSourceLoc(in: self)
     let rSquareLoc = node.rightSquare.bridgedSourceLoc(in: self)
     return BridgedArrayTypeRepr.createParsed(
-      self.ctx, base: elementType, leftSquareLoc: lSquareLoc, 
+      self.ctx,
+      base: elementType,
+      leftSquareLoc: lSquareLoc,
       rightSquareLoc: rSquareLoc
     )
   }
@@ -90,8 +92,12 @@ extension ASTGenVisitor {
     let lSquareLoc = node.leftSquare.bridgedSourceLoc(in: self)
     let rSquareLoc = node.rightSquare.bridgedSourceLoc(in: self)
     return BridgedDictionaryTypeRepr.createParsed(
-      self.ctx, leftSquareLoc: lSquareLoc, keyType: keyType, colonLoc: colonLoc,
-      valueType: valueType, rightSquareLoc: rSquareLoc
+      self.ctx,
+      leftSquareLoc: lSquareLoc,
+      keyType: keyType,
+      colonLoc: colonLoc,
+      valueType: valueType,
+      rightSquareLoc: rSquareLoc
     )
   }
 
@@ -100,12 +106,16 @@ extension ASTGenVisitor {
     let tyLoc = node.metatypeSpecifier.bridgedSourceLoc(in: self)
     if node.metatypeSpecifier.text == "Type" {
       return BridgedMetatypeTypeRepr.createParsed(
-        self.ctx, base: baseType, typeKeywordLoc: tyLoc
+        self.ctx,
+        base: baseType,
+        typeKeywordLoc: tyLoc
       )
     } else {
       assert(node.metatypeSpecifier.text == "Protocol")
       return BridgedProtocolTypeRepr.createParsed(
-        self.ctx, base: baseType, protocolKeywordLoc: tyLoc
+        self.ctx,
+        base: baseType,
+        protocolKeywordLoc: tyLoc
       )
     }
   }
@@ -114,7 +124,9 @@ extension ASTGenVisitor {
     let base = generate(node.wrappedType)
     let exclaimLoc = node.exclamationMark.bridgedSourceLoc(in: self)
     return BridgedImplicitlyUnwrappedOptionalTypeRepr.createParsed(
-      self.ctx, base: base, exclaimLoc: exclaimLoc
+      self.ctx,
+      base: base,
+      exclaimLoc: exclaimLoc
     )
   }
 
@@ -122,7 +134,9 @@ extension ASTGenVisitor {
     let base = generate(node.wrappedType)
     let questionLoc = node.questionMark.bridgedSourceLoc(in: self)
     return BridgedOptionalTypeRepr.createParsed(
-      self.ctx, base: base, questionLoc: questionLoc
+      self.ctx,
+      base: base,
+      questionLoc: questionLoc
     )
   }
 
@@ -130,7 +144,9 @@ extension ASTGenVisitor {
     let base = generate(node.repetitionPattern)
     let repeatLoc = node.repeatKeyword.bridgedSourceLoc(in: self)
     return BridgedPackExpansionTypeRepr.createParsed(
-      self.ctx, base: base, repeatKeywordLoc: repeatLoc
+      self.ctx,
+      base: base,
+      repeatKeywordLoc: repeatLoc
     )
   }
 
@@ -185,12 +201,16 @@ extension ASTGenVisitor {
     let baseTy = generate(node.constraint)
     if node.someOrAnySpecifier.text == "some" {
       return BridgedOpaqueReturnTypeRepr.createParsed(
-        self.ctx, someKeywordLoc: someOrAnyLoc, base: baseTy
+        self.ctx,
+        someKeywordLoc: someOrAnyLoc,
+        base: baseTy
       )
     } else {
       assert(node.someOrAnySpecifier.text == "any")
       return BridgedExistentialTypeRepr.createParsed(
-        self.ctx, anyKeywordLoc: someOrAnyLoc, base: baseTy
+        self.ctx,
+        anyKeywordLoc: someOrAnyLoc,
+        base: baseTy
       )
     }
   }
@@ -221,7 +241,9 @@ extension ASTGenVisitor {
     if let specifier = node.specifier {
       if let kind = BridgedAttributedTypeSpecifier(from: specifier.tokenKind) {
         type = BridgedSpecifierTypeRepr.createParsed(
-          self.ctx, base: type, specifier: kind, 
+          self.ctx,
+          base: type,
+          specifier: kind,
           specifierLoc: specifier.bridgedSourceLoc(in: self)
         )
       } else {
@@ -252,33 +274,35 @@ extension ASTGenVisitor {
         let atLoc = attribute.atSign.bridgedSourceLoc(in: self)
         let attrLoc = nameSyntax.bridgedSourceLoc(in: self)
         switch typeAttrKind {
-          // SIL attributes
-          // FIXME: Diagnose if not in SIL mode? Or should that move to the
-          // type checker?
-          case .out, .in, .owned, .unowned_inner_pointer, .guaranteed,
-               .autoreleased, .callee_owned, .callee_guaranteed, .objc_metatype,
-               .sil_weak, .sil_unowned, .inout, .block_storage, .box,
-               .dynamic_self, .sil_unmanaged, .error, .error_indirect,
-               .error_unowned, .direct, .inout_aliasable,
-               .in_guaranteed, .in_constant, .captures_generics, .moveOnly:
-            fallthrough
-
-          case .autoclosure, .escaping, .noescape, .noDerivative, .async,
-            .sendable, .retroactive, .unchecked, ._local, ._noMetadata,
-            .pack_owned, .pack_guaranteed, .pack_inout, .pack_out,
-            .pseudogeneric, .yields, .yield_once, .yield_many, .thin, .thick,
-            .count, .unimplementable:
-            TypeAttributes_addSimpleAttr(typeAttributes, typeAttrKind, atLoc, attrLoc)
-
-          case .opened, .pack_element, .differentiable, .convention,
-            ._opaqueReturnTypeOf:
-            // FIXME: These require more complicated checks
-            break
+        // SIL attributes
+        // FIXME: Diagnose if not in SIL mode? Or should that move to the
+        // type checker?
+        case .out, .in, .owned, .unowned_inner_pointer, .guaranteed,
+          .autoreleased, .callee_owned, .callee_guaranteed, .objc_metatype,
+          .sil_weak, .sil_unowned, .inout, .block_storage, .box,
+          .dynamic_self, .sil_unmanaged, .error, .error_indirect,
+          .error_unowned, .direct, .inout_aliasable,
+          .in_guaranteed, .in_constant, .captures_generics, .moveOnly:
+          fallthrough
+
+        case .autoclosure, .escaping, .noescape, .noDerivative, .async,
+          .sendable, .retroactive, .unchecked, ._local, ._noMetadata,
+          .pack_owned, .pack_guaranteed, .pack_inout, .pack_out,
+          .pseudogeneric, .yields, .yield_once, .yield_many, .thin, .thick,
+          .count, .unimplementable:
+          TypeAttributes_addSimpleAttr(typeAttributes, typeAttrKind, atLoc, attrLoc)
+
+        case .opened, .pack_element, .differentiable, .convention,
+          ._opaqueReturnTypeOf:
+          // FIXME: These require more complicated checks
+          break
         }
       }
 
       type = BridgedAttributedTypeRepr.createParsed(
-        self.ctx, base: type, attributes: typeAttributes
+        self.ctx,
+        base: type,
+        attributes: typeAttributes
       )
     }
 
@@ -294,7 +318,9 @@ extension ASTGenVisitor {
       var type = generate(element.type)
       if let ellipsis = element.ellipsis {
         type = BridgedVarargTypeRepr.createParsed(
-          self.ctx, base: type, ellipsisLoc: ellipsis.bridgedSourceLoc(in: self)
+          self.ctx,
+          base: type,
+          ellipsisLoc: ellipsis.bridgedSourceLoc(in: self)
         )
       }
 
@@ -323,16 +349,19 @@ func buildTypeRepr(
   endTypeLocPtr: UnsafeMutablePointer<UnsafePointer<UInt8>?>
 ) -> UnsafeMutableRawPointer? {
   let sourceFile = sourceFilePtr.bindMemory(
-    to: ExportedSourceFile.self, capacity: 1
+    to: ExportedSourceFile.self,
+    capacity: 1
   )
 
   // Find the type syntax node.
-  guard let typeSyntax = findSyntaxNodeInSourceFile(
-    sourceFilePtr: sourceFilePtr,
-    sourceLocationPtr: typeLocPtr,
-    type: TypeSyntax.self,
-    wantOutermost: true
-  ) else {
+  guard
+    let typeSyntax = findSyntaxNodeInSourceFile(
+      sourceFilePtr: sourceFilePtr,
+      sourceLocationPtr: typeLocPtr,
+      type: TypeSyntax.self,
+      wantOutermost: true
+    )
+  else {
     // FIXME: Produce an error
     return nil
   }
diff --git a/lib/ASTGen/Sources/LLVMJSON/LLVMJSON.swift b/lib/ASTGen/Sources/LLVMJSON/LLVMJSON.swift
index 4cfcbb0c25567..0231235508701 100644
--- a/lib/ASTGen/Sources/LLVMJSON/LLVMJSON.swift
+++ b/lib/ASTGen/Sources/LLVMJSON/LLVMJSON.swift
@@ -71,20 +71,21 @@ fileprivate struct LLVMJSONDecoding: Decoder {
 
   var valuePtr: UnsafeMutableRawPointer
   var codingPath: [CodingKey]
-  var userInfo: [CodingUserInfoKey : Any]
+  var userInfo: [CodingUserInfoKey: Any]
 
-  init(from valuePtr: UnsafeMutableRawPointer, codingPath: [CodingKey] = [], userInfo: [CodingUserInfoKey : Any] = [:]) {
+  init(from valuePtr: UnsafeMutableRawPointer, codingPath: [CodingKey] = [], userInfo: [CodingUserInfoKey: Any] = [:]) {
     self.valuePtr = valuePtr
     self.codingPath = codingPath
     self.userInfo = userInfo
   }
 
-  func container<Key>(keyedBy type: Key.Type) throws -> KeyedDecodingContainer<Key> where Key : CodingKey {
+  func container<Key>(keyedBy type: Key.Type) throws -> KeyedDecodingContainer<Key> where Key: CodingKey {
     var objectPtr: UnsafeMutableRawPointer? = nil
     if JSON_value_getAsObject(valuePtr, &objectPtr) {
       throw DecodingError.typeMismatch(
         KeyedContainer<Key>.self,
-        .init(codingPath: codingPath, debugDescription: "type mismatch"))
+        .init(codingPath: codingPath, debugDescription: "type mismatch")
+      )
     }
     return KeyedDecodingContainer(KeyedContainer<Key>(objectPtr: objectPtr!, codingPath: codingPath))
   }
@@ -94,7 +95,8 @@ fileprivate struct LLVMJSONDecoding: Decoder {
     if JSON_value_getAsArray(valuePtr, &arrayPtr) {
       throw DecodingError.typeMismatch(
         UnkeyedContainer.self,
-        .init(codingPath: codingPath, debugDescription: "type mismatch"))
+        .init(codingPath: codingPath, debugDescription: "type mismatch")
+      )
     }
     return UnkeyedContainer(arrayPtr: arrayPtr!, codingPath: codingPath)
   }
@@ -195,7 +197,7 @@ extension LLVMJSONDecoding.SingleValueContainer: SingleValueDecodingContainer {
     try _decodeInteger(UInt64.self)
   }
 
-  func decode<T>(_ type: T.Type) throws -> T where T : Decodable {
+  func decode<T>(_ type: T.Type) throws -> T where T: Decodable {
     let decoder = LLVMJSONDecoding(from: valuePtr, codingPath: codingPath)
     return try T.init(from: decoder)
   }
@@ -210,7 +212,7 @@ extension LLVMJSONDecoding.KeyedContainer: KeyedDecodingContainerProtocol {
     var keys: [Key] = []
     let size = JSON_object_getSize(objectPtr)
     keys.reserveCapacity(size)
-    for i in 0 ..< size {
+    for i in 0..<size {
       let keyData = JSON_object_getKey(objectPtr, i)
       if let key = Key(stringValue: String(keyData)) {
         keys.append(key);
@@ -238,11 +240,12 @@ extension LLVMJSONDecoding.KeyedContainer: KeyedDecodingContainerProtocol {
   }
 
   private func _getSingle(forKey key: Key) throws -> SingleContainer {
-    SingleContainer(valuePtr: try _getValueOrThrow(forKey: key),
-                    codingPath: codingPath + [key])
+    SingleContainer(
+      valuePtr: try _getValueOrThrow(forKey: key),
+      codingPath: codingPath + [key]
+    )
   }
 
-
   private func _typeMismatchError(_ type: Any.Type, forKey key: Key) -> DecodingError {
     DecodingError.typeMismatch(type, .init(codingPath: codingPath + [key], debugDescription: "type misatch"))
   }
@@ -307,7 +310,7 @@ extension LLVMJSONDecoding.KeyedContainer: KeyedDecodingContainerProtocol {
     try _getSingle(forKey: key).decode(type)
   }
 
-  func decode<T>(_ type: T.Type, forKey key: Key) throws -> T where T : Decodable {
+  func decode<T>(_ type: T.Type, forKey key: Key) throws -> T where T: Decodable {
     try _getSingle(forKey: key).decode(type)
   }
 
@@ -381,12 +384,14 @@ extension LLVMJSONDecoding.KeyedContainer: KeyedDecodingContainerProtocol {
     return try decode(type, forKey: key)
   }
 
-  func decodeIfPresent<T>(_ type: T.Type, forKey key: Key) throws -> T? where T : Decodable {
+  func decodeIfPresent<T>(_ type: T.Type, forKey key: Key) throws -> T? where T: Decodable {
     guard contains(key) else { return nil }
     return try decode(type, forKey: key)
   }
 
-  func nestedContainer<NestedKey>(keyedBy type: NestedKey.Type, forKey key: Key) throws -> KeyedDecodingContainer<NestedKey> where NestedKey : CodingKey {
+  func nestedContainer<NestedKey>(keyedBy type: NestedKey.Type, forKey key: Key) throws -> KeyedDecodingContainer<
+    NestedKey
+  > where NestedKey: CodingKey {
     var objectPtr: UnsafeMutableRawPointer? = nil
     if JSON_value_getAsObject(try _getValueOrThrow(forKey: key), &objectPtr) {
       throw _typeMismatchError(KeyedDecodingContainer<NestedKey>.self, forKey: key)
@@ -439,7 +444,8 @@ extension LLVMJSONDecoding.UnkeyedContainer: UnkeyedDecodingContainer {
     guard !isAtEnd else {
       throw DecodingError.valueNotFound(
         Bool.self,
-        .init(codingPath: codingPath, debugDescription: "tried to decode too many"))
+        .init(codingPath: codingPath, debugDescription: "tried to decode too many")
+      )
     }
     let index = currentIndex
     currentIndex += 1
@@ -447,8 +453,10 @@ extension LLVMJSONDecoding.UnkeyedContainer: UnkeyedDecodingContainer {
   }
 
   private mutating func _getSingle() throws -> SingleContainer {
-    SingleContainer(valuePtr: try _getValueOrThrow(),
-                    codingPath: codingPath + [IndexKey(intValue: currentIndex)])
+    SingleContainer(
+      valuePtr: try _getValueOrThrow(),
+      codingPath: codingPath + [IndexKey(intValue: currentIndex)]
+    )
   }
 
   mutating func decodeNil() throws -> Bool {
@@ -511,17 +519,22 @@ extension LLVMJSONDecoding.UnkeyedContainer: UnkeyedDecodingContainer {
     try _getSingle().decode(type)
   }
 
-  mutating func decode<T>(_ type: T.Type) throws -> T where T : Decodable {
+  mutating func decode<T>(_ type: T.Type) throws -> T where T: Decodable {
     try _getSingle().decode(type)
   }
 
   private func _typeMismatchError(_ type: Any.Type) -> DecodingError {
     DecodingError.typeMismatch(
-      type, .init(codingPath: codingPath + [IndexKey(intValue: currentIndex)],
-                  debugDescription: "type misatch"))
+      type,
+      .init(
+        codingPath: codingPath + [IndexKey(intValue: currentIndex)],
+        debugDescription: "type misatch"
+      )
+    )
   }
 
-  mutating func nestedContainer<NestedKey>(keyedBy type: NestedKey.Type) throws -> KeyedDecodingContainer<NestedKey> where NestedKey : CodingKey {
+  mutating func nestedContainer<NestedKey>(keyedBy type: NestedKey.Type) throws -> KeyedDecodingContainer<NestedKey>
+  where NestedKey: CodingKey {
     var objectPtr: UnsafeMutableRawPointer? = nil
     let newPath = codingPath + [IndexKey(intValue: currentIndex)]
     if JSON_value_getAsObject(try _getValueOrThrow(), &objectPtr) {
@@ -566,15 +579,15 @@ fileprivate struct LLVMJSONEncoding: Encoder {
 
   var valuePtr: UnsafeMutableRawPointer
   var codingPath: [CodingKey]
-  var userInfo: [CodingUserInfoKey : Any]
+  var userInfo: [CodingUserInfoKey: Any]
 
-  init(to valuePtr: UnsafeMutableRawPointer, codingPath: [CodingKey] = [], userInfo: [CodingUserInfoKey : Any] = [:]) {
+  init(to valuePtr: UnsafeMutableRawPointer, codingPath: [CodingKey] = [], userInfo: [CodingUserInfoKey: Any] = [:]) {
     self.valuePtr = valuePtr
     self.codingPath = codingPath
     self.userInfo = userInfo
   }
 
-  func container<Key>(keyedBy type: Key.Type) -> KeyedEncodingContainer<Key> where Key : CodingKey {
+  func container<Key>(keyedBy type: Key.Type) -> KeyedEncodingContainer<Key> where Key: CodingKey {
     let objectPtr = JSON_value_emplaceNewObject(valuePtr)
     return KeyedEncodingContainer(KeyedContainer(objectPtr: objectPtr, codingPath: codingPath))
   }
@@ -653,13 +666,15 @@ extension LLVMJSONEncoding.KeyedContainer: KeyedEncodingContainerProtocol {
     JSON_object_setInteger(objectPtr, key.stringValue, Int64(value))
   }
 
-  mutating func encode<T>(_ value: T, forKey key: Key) throws where T : Encodable {
+  mutating func encode<T>(_ value: T, forKey key: Key) throws where T: Encodable {
     let valuePtr = JSON_object_setNewValue(objectPtr, key.stringValue)
     let encoder = LLVMJSONEncoding(to: valuePtr, codingPath: codingPath + [key])
     try value.encode(to: encoder)
   }
 
-  mutating func nestedContainer<NestedKey>(keyedBy keyType: NestedKey.Type, forKey key: Key) -> KeyedEncodingContainer<NestedKey> where NestedKey : CodingKey {
+  mutating func nestedContainer<NestedKey>(keyedBy keyType: NestedKey.Type, forKey key: Key) -> KeyedEncodingContainer<
+    NestedKey
+  > where NestedKey: CodingKey {
     let nestedObjectPtr = JSON_object_setNewObject(objectPtr, key.stringValue)
     return KeyedEncodingContainer(KeyedContainer(objectPtr: nestedObjectPtr, codingPath: codingPath + [key]))
   }
@@ -755,18 +770,23 @@ extension LLVMJSONEncoding.UnkeyedContainer: UnkeyedEncodingContainer {
     JSON_array_pushInteger(arrayPtr, Int64(value))
   }
 
-  mutating func encode<T>(_ value: T) throws where T : Encodable {
+  mutating func encode<T>(_ value: T) throws where T: Encodable {
     let key = IndexKey(intValue: self.count)
     let valuePtr = JSON_array_pushNewValue(arrayPtr)
     let encoder = LLVMJSONEncoding(to: valuePtr, codingPath: codingPath + [key])
     try value.encode(to: encoder)
   }
 
-  mutating func nestedContainer<NestedKey>(keyedBy keyType: NestedKey.Type) -> KeyedEncodingContainer<NestedKey> where NestedKey : CodingKey {
+  mutating func nestedContainer<NestedKey>(keyedBy keyType: NestedKey.Type) -> KeyedEncodingContainer<NestedKey>
+  where NestedKey: CodingKey {
     let key = IndexKey(intValue: self.count)
     let nestedObjectPtr = JSON_array_pushNewObject(arrayPtr)
-    return KeyedEncodingContainer(KeyedContainer(objectPtr: nestedObjectPtr,
-                                                 codingPath: codingPath + [key]))
+    return KeyedEncodingContainer(
+      KeyedContainer(
+        objectPtr: nestedObjectPtr,
+        codingPath: codingPath + [key]
+      )
+    )
   }
 
   mutating func nestedUnkeyedContainer() -> UnkeyedEncodingContainer {
@@ -841,7 +861,7 @@ extension LLVMJSONEncoding.SingleValueContainer: SingleValueEncodingContainer {
     JSON_value_emplaceInteger(valuePtr, Int64(value));
   }
 
-  mutating func encode<T>(_ value: T) throws where T : Encodable {
+  mutating func encode<T>(_ value: T) throws where T: Encodable {
     let encoder = LLVMJSONEncoding(to: valuePtr, codingPath: codingPath)
     try value.encode(to: encoder)
   }