Merge branch 'main' into closure-capture-syntax-node-update

Author: MAJKFL

Package.swift

@@ -143,7 +143,7 @@ let package = Package(
 
     .target(
       name: "SwiftIfConfig",
-      dependencies: ["SwiftSyntax", "SwiftOperators"],
+      dependencies: ["SwiftSyntax", "SwiftDiagnostics", "SwiftOperators"],
       exclude: ["CMakeLists.txt"]
     ),
 

Release Notes/601.md

@@ -15,6 +15,10 @@
   - Description: This method translates an error into one or more diagnostics, recognizing `DiagnosticsError` and `DiagnosticMessage` instances or providing its own `Diagnostic` as needed.
   - Pull Request: https://github.com/swiftlang/swift-syntax/pull/1816
 
+- Added a new library `SwiftIfConfig`.
+  - Description: This new library provides facilities for evaluating `#if` conditions and determining which regions of a syntax tree are active according to a given build configuration.
+  - Pull Request: https://github.com/swiftlang/swift-syntax/pull/1816
+
 ## API Behavior Changes
 
 - `SyntaxProtocol.trimmed` detaches the node
@@ -38,7 +42,13 @@
   - Description: Allows retrieving the radix value from the `literal.text`.
   - Issue: https://github.com/apple/swift-syntax/issues/405
   - Pull Request: https://github.com/apple/swift-syntax/pull/2605
-  
+
+- `FixIt.Change` gained a new case `replaceChild(data:)`.
+  - Description: The new case covers the replacement of a child node with another node.
+  - Issue: https://github.com/swiftlang/swift-syntax/issues/2205
+  - Pull Request: https://github.com/swiftlang/swift-syntax/pull/2758
+  - Migration steps: In exhaustive switches over `FixIt.Change`, cover the new case.
+
 - `ClosureCaptureSyntax.name` is no longer optional.
   - Description: Due to the new `ClosureCaptureSyntax` node structure, `name` property is non-optional.
   - Pull request: https://github.com/swiftlang/swift-syntax/pull/2763 

Sources/SwiftCompilerPluginMessageHandling/Diagnostics.swift

@@ -130,12 +130,15 @@ extension PluginMessage.Diagnostic {
               to: .afterTrailingTrivia
             )
             text = newTrivia.description
+          case .replaceChild(let replaceChildData):
+            range = sourceManager.range(replaceChildData.replacementRange, in: replaceChildData.parent)
+            text = replaceChildData.newChild.description
           #if RESILIENT_LIBRARIES
           @unknown default:
             fatalError()
           #endif
           }
-          guard let range = range else {
+          guard let range else {
             return nil
           }
           return .init(

Sources/SwiftCompilerPluginMessageHandling/PluginMacroExpansionContext.swift

@@ -169,20 +169,25 @@ class SourceManager {
     of node: Syntax,
     from startKind: PositionInSyntaxNode = .afterLeadingTrivia,
     to endKind: PositionInSyntaxNode = .beforeTrailingTrivia
+  ) -> SourceRange? {
+    range(node.position(at: startKind)..<node.position(at: endKind), in: node)
+  }
+
+  /// Get ``SourceRange`` (file name + UTF-8 offset range) of `localRange` in `node`'s root node, which must be one
+  /// of the returned values from `add(_:)`.
+  func range(
+    _ localRange: @autoclosure () -> Range<AbsolutePosition>,
+    in node: some SyntaxProtocol
   ) -> SourceRange? {
     guard let base = self.knownSourceSyntax[node.root.id] else {
       return nil
     }
-    let localStartPosition = node.position(at: startKind)
-    let localEndPosition = node.position(at: endKind)
-    precondition(localStartPosition <= localEndPosition)
-
     let positionOffset = base.location.offset
-
+    let localRange = localRange()
     return SourceRange(
       fileName: base.location.fileName,
-      startUTF8Offset: localStartPosition.advanced(by: positionOffset).utf8Offset,
-      endUTF8Offset: localEndPosition.advanced(by: positionOffset).utf8Offset
+      startUTF8Offset: localRange.lowerBound.advanced(by: positionOffset).utf8Offset,
+      endUTF8Offset: localRange.upperBound.advanced(by: positionOffset).utf8Offset
     )
   }
 

Sources/SwiftDiagnostics/Convenience.swift

@@ -51,4 +51,20 @@ extension FixIt {
       ]
     )
   }
+
+  public static func replaceChild<Parent: SyntaxProtocol, Child: SyntaxProtocol>(
+    message: FixItMessage,
+    parent: Parent,
+    replacingChildAt keyPath: WritableKeyPath<Parent, Child?> & Sendable,
+    with newChild: Child
+  ) -> Self {
+    FixIt(
+      message: message,
+      changes: [
+        .replaceChild(
+          data: FixIt.Change.ReplacingOptionalChildData(parent: parent, newChild: newChild, keyPath: keyPath)
+        )
+      ]
+    )
+  }
 }

Sources/SwiftDiagnostics/FixIt.swift

@@ -27,15 +27,56 @@ public protocol FixItMessage: Sendable {
   var fixItID: MessageID { get }
 }
 
+/// Types conforming to this protocol provide the data required for replacing a child node of a parent node.
+///
+/// Conforming types should ensure the child of ``parent`` to be replaced at ``replacementRange`` is type-compatible
+/// with ``newChild``. Conforming types are stored as type-erased existentials (i.e. `any ReplacingChildData`) in
+///  ``FixIt/Change/replaceChild(data:)`` to keep ``FixIt`` type-erased.
+public protocol ReplacingChildData: Sendable {
+  associatedtype Parent: SyntaxProtocol
+  associatedtype Child: SyntaxProtocol
+
+  /// The node whose child node at ``replacementRange`` to be replaced by ``newChild``.
+  var parent: Parent { get }
+
+  /// The node to replace the child node of ``parent`` at ``replacementRange``.
+  var newChild: Child { get }
+
+  /// The absolute position range of the child node to be replaced.
+  ///
+  /// If a nil child node is to be replaced, conforming types should provide a zero-length range with both bounds
+  /// denoting the start position of ``newChild`` in ``parent`` after replacement.
+  var replacementRange: Range<AbsolutePosition> { get }
+}
+
 /// A Fix-It that can be applied to resolve a diagnostic.
 public struct FixIt: Sendable {
   public enum Change: Sendable {
+    struct ReplacingOptionalChildData<Parent: SyntaxProtocol, Child: SyntaxProtocol>: ReplacingChildData {
+      let parent: Parent
+      let newChild: Child
+      let keyPath: WritableKeyPath<Parent, Child?> & Sendable
+
+      var replacementRange: Range<AbsolutePosition> {
+        // need to upcast keyPath to strip Sendable for older Swift versions
+        let keyPath: WritableKeyPath<Parent, Child?> = keyPath
+        if let oldChild = parent[keyPath: keyPath] {
+          return oldChild.range
+        } else {
+          let newChild = parent.with(keyPath, newChild)[keyPath: keyPath]!
+          return newChild.position..<newChild.position
+        }
+      }
+    }
+
     /// Replace `oldNode` by `newNode`.
     case replace(oldNode: Syntax, newNode: Syntax)
     /// Replace the leading trivia on the given token
     case replaceLeadingTrivia(token: TokenSyntax, newTrivia: Trivia)
     /// Replace the trailing trivia on the given token
     case replaceTrailingTrivia(token: TokenSyntax, newTrivia: Trivia)
+    /// Replace the child node of the given parent node at the given replacement range with the given new child node
+    case replaceChild(data: any ReplacingChildData)
   }
 
   /// A description of what this Fix-It performs.
@@ -89,6 +130,12 @@ private extension FixIt.Change {
         range: token.endPositionBeforeTrailingTrivia..<token.endPosition,
         replacement: newTrivia.description
       )
+
+    case .replaceChild(let replacingChildData):
+      return SourceEdit(
+        range: replacingChildData.replacementRange,
+        replacement: replacingChildData.newChild.description
+      )
     }
   }
 }

Sources/SwiftIfConfig/ActiveSyntaxRewriter.swift

@@ -10,15 +10,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-//
-// This file defines the SyntaxRewriter, a class that performs a standard walk
-// and tree-rebuilding pattern.
-//
-// Subclassers of this class can override the walking behavior for any syntax
-// node and transform nodes however they like.
-//
-//===----------------------------------------------------------------------===//
-
 import SwiftDiagnostics
 import SwiftSyntax
 
@@ -34,15 +25,17 @@ extension SyntaxProtocol {
   /// clauses, e.g., `#if FOO > 10`, then the condition will be
   /// considered to have failed and the clauses's elements will be
   /// removed.
-  public func removingInactive(in configuration: some BuildConfiguration) -> (Syntax, [Diagnostic]) {
+  public func removingInactive(
+    in configuration: some BuildConfiguration
+  ) -> (result: Syntax, diagnostics: [Diagnostic]) {
     // First pass: Find all of the active clauses for the #ifs we need to
     // visit, along with any diagnostics produced along the way. This process
     // does not change the tree in any way.
     let visitor = ActiveSyntaxVisitor(viewMode: .sourceAccurate, configuration: configuration)
     visitor.walk(self)
 
     // If there were no active clauses to visit, we're done!
-    if visitor.numIfClausesVisited == 0 {
+    if !visitor.visitedAnyIfClauses {
       return (Syntax(self), visitor.diagnostics)
     }
 
@@ -88,12 +81,13 @@ extension SyntaxProtocol {
 /// than trivia).
 class ActiveSyntaxRewriter<Configuration: BuildConfiguration>: SyntaxRewriter {
   let configuration: Configuration
+  var diagnostics: [Diagnostic] = []
 
   init(configuration: Configuration) {
     self.configuration = configuration
   }
 
-  private func dropInactive<List: Collection & SyntaxCollection>(
+  private func dropInactive<List: SyntaxCollection>(
     _ node: List,
     elementAsIfConfig: (List.Element) -> IfConfigDeclSyntax?
   ) -> List {
@@ -105,7 +99,10 @@ class ActiveSyntaxRewriter<Configuration: BuildConfiguration>: SyntaxRewriter {
       // Find #ifs within the list.
       if let ifConfigDecl = elementAsIfConfig(element) {
         // Retrieve the active `#if` clause
-        let activeClause = ifConfigDecl.activeClause(in: configuration)
+        let (activeClause, localDiagnostics) = ifConfigDecl.activeClause(in: configuration)
+
+        // Add these diagnostics.
+        diagnostics.append(contentsOf: localDiagnostics)
 
         // If this is the first element that changed, note that we have
         // changes and add all prior elements to the list of new elements.
@@ -255,7 +252,8 @@ class ActiveSyntaxRewriter<Configuration: BuildConfiguration>: SyntaxRewriter {
       return dropInactive(outerBase: base, postfixIfConfig: postfixIfConfig)
     }
 
-    preconditionFailure("Unhandled postfix expression in #if elimination")
+    assertionFailure("Unhandled postfix expression in #if elimination")
+    return postfix
   }
 
   /// Drop inactive regions from a postfix `#if` configuration, applying the
@@ -265,7 +263,10 @@ class ActiveSyntaxRewriter<Configuration: BuildConfiguration>: SyntaxRewriter {
     postfixIfConfig: PostfixIfConfigExprSyntax
   ) -> ExprSyntax {
     // Retrieve the active `if` clause.
-    let activeClause = postfixIfConfig.config.activeClause(in: configuration)
+    let (activeClause, localDiagnostics) = postfixIfConfig.config.activeClause(in: configuration)
+
+    // Record these diagnostics.
+    diagnostics.append(contentsOf: localDiagnostics)
 
     guard case .postfixExpression(let postfixExpr) = activeClause?.elements
     else {

Sources/SwiftIfConfig/ActiveSyntaxVisitor.swift

@@ -9,6 +9,7 @@
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 //
 //===----------------------------------------------------------------------===//
+
 import SwiftDiagnostics
 import SwiftSyntax
 
@@ -36,34 +37,34 @@ import SwiftSyntax
 /// it would not visit either `f` or `g`.
 ///
 /// All notes visited by this visitor will have the "active" state, i.e.,
-/// `node.isActive(in: configuration)` will evaluate to `.active` or will
-/// throw. When errors occur, they will be recorded in the set of
-/// diagnostics.
+/// `node.isActive(in: configuration)` will have evaluated to `.active`.
+/// When errors occur, they will be recorded in the array of diagnostics.
 open class ActiveSyntaxVisitor<Configuration: BuildConfiguration>: SyntaxVisitor {
   /// The build configuration, which will be queried for each relevant `#if`.
   public let configuration: Configuration
 
-  /// The set of diagnostics accumulated during this walk of active syntax.
-  public var diagnostics: [Diagnostic] = []
+  /// The diagnostics accumulated during this walk of active syntax.
+  public private(set) var diagnostics: [Diagnostic] = []
 
-  /// The number of "#if" clauses that were visited.
-  var numIfClausesVisited: Int = 0
+  /// Whether we visited any "#if" clauses.
+  var visitedAnyIfClauses: Bool = false
 
   public init(viewMode: SyntaxTreeViewMode, configuration: Configuration) {
     self.configuration = configuration
     super.init(viewMode: viewMode)
   }
 
   open override func visit(_ node: IfConfigDeclSyntax) -> SyntaxVisitorContinueKind {
-    let activeClause = node.activeClause(in: configuration) { diag in
-      self.diagnostics.append(diag)
-    }
+    // Note: there is a clone of this code in ActiveSyntaxAnyVisitor. If you
+    // change one, please also change the other.
+    let (activeClause, localDiagnostics) = node.activeClause(in: configuration)
+    diagnostics.append(contentsOf: localDiagnostics)
 
-    numIfClausesVisited += 1
+    visitedAnyIfClauses = true
 
     // If there is an active clause, visit it's children.
     if let activeClause, let elements = activeClause.elements {
-      walk(Syntax(elements))
+      walk(elements)
     }
 
     // Skip everything else in the #if.
@@ -95,32 +96,30 @@ open class ActiveSyntaxVisitor<Configuration: BuildConfiguration>: SyntaxVisitor
 /// it would not visit either `f` or `g`.
 ///
 /// All notes visited by this visitor will have the "active" state, i.e.,
-/// `node.isActive(in: configuration)` will evaluate to `.active` or will
-/// throw.
-///
-/// All notes visited by this visitor will have the "active" state, i.e.,
-/// `node.isActive(in: configuration)` will evaluate to `.active` or will
-/// throw. When errors occur, they will be recorded in the set of
-/// diagnostivs.
+/// `node.isActive(in: configuration)` will have evaluated to `.active`.
+/// When errors occur, they will be recorded in the array of diagnostics.
 open class ActiveSyntaxAnyVisitor<Configuration: BuildConfiguration>: SyntaxAnyVisitor {
   /// The build configuration, which will be queried for each relevant `#if`.
   public let configuration: Configuration
 
-  /// The set of diagnostics accumulated during this walk of active syntax.
-  public var diagnostics: [Diagnostic] = []
+  /// The diagnostics accumulated during this walk of active syntax.
+  public private(set) var diagnostics: [Diagnostic] = []
 
   public init(viewMode: SyntaxTreeViewMode, configuration: Configuration) {
     self.configuration = configuration
     super.init(viewMode: viewMode)
   }
 
   open override func visit(_ node: IfConfigDeclSyntax) -> SyntaxVisitorContinueKind {
+    // Note: there is a clone of this code in ActiveSyntaxVisitor. If you
+    // change one, please also change the other.
+
     // If there is an active clause, visit it's children.
-    let activeClause = node.activeClause(in: configuration) { diag in
-      self.diagnostics.append(diag)
-    }
+    let (activeClause, localDiagnostics) = node.activeClause(in: configuration)
+    diagnostics.append(contentsOf: localDiagnostics)
+
     if let activeClause, let elements = activeClause.elements {
-      walk(Syntax(elements))
+      walk(elements)
     }
 
     // Skip everything else in the #if.

Sources/SwiftIfConfig/BuildConfiguration.swift

@@ -253,7 +253,7 @@ public protocol BuildConfiguration {
   ///
   /// The language version can be queried with the `swift` directive that checks
   /// how the supported language version compares, as described by
-  /// [SE-0212](https://github.com/apple/swift-evolution/blob/main/proposals/0212-compiler-version-directive.md). For example:
+  /// [SE-0212](https://github.com/swiftlang/swift-evolution/blob/main/proposals/0212-compiler-version-directive.md). For example:
   ///
   /// ```swift
   /// #if swift(>=5.5)

Sources/SwiftIfConfig/CMakeLists.txt

@@ -11,7 +11,7 @@ add_swift_syntax_library(SwiftIfConfig
   ActiveSyntaxRewriter.swift
   BuildConfiguration.swift
   ConfiguredRegions.swift
-  ConfiguredRegionState.swift
+  IfConfigRegionState.swift
   IfConfigDecl+IfConfig.swift
   IfConfigError.swift
   IfConfigEvaluation.swift
@@ -25,5 +25,4 @@ add_swift_syntax_library(SwiftIfConfig
 target_link_swift_syntax_libraries(SwiftIfConfig PUBLIC
   SwiftSyntax
   SwiftDiagnostics
-  SwiftOperators
-  SwiftParser)
+  SwiftOperators)