Merge pull request swiftlang#1369 from DougGregor/macros-abstract-source-location

Author: DougGregor

Sources/SwiftSyntaxMacros/AbstractSourceLocation.swift

@@ -0,0 +1,25 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2023 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import SwiftSyntax
+
+/// Abstractly represents a source location in the macro.
+public struct AbstractSourceLocation {
+  /// A primary expression that represents the file and is `ExpressibleByStringLiteral`.
+  public let file: ExprSyntax
+
+  /// A primary expression that represents the line and is `ExpressibleByIntegerLiteral`.
+  public let line: ExprSyntax
+
+  /// A primary expression that represents the column and is `ExpressibleByIntegerLiteral`.
+  public let column: ExprSyntax
+}

Sources/SwiftSyntaxMacros/CMakeLists.txt

@@ -19,6 +19,7 @@ add_swift_host_library(SwiftSyntaxMacros
   MacroProtocols/MemberMacro.swift
   MacroProtocols/PeerMacro.swift
 
+  AbstractSourceLocation.swift
   BasicMacroExpansionContext.swift
   MacroExpansionContext.swift
   MacroSystem.swift

Sources/SwiftSyntaxMacros/MacroExpansionContext.swift

@@ -10,8 +10,9 @@
 //
 //===----------------------------------------------------------------------===//
 
-import SwiftSyntax
 import SwiftDiagnostics
+import SwiftSyntax
+import SwiftSyntaxBuilder
 
 /// Interface to extract information about the context in which a given
 /// macro is expanded.
@@ -41,11 +42,31 @@ public protocol MacroExpansionContext: AnyObject {
   /// - Returns: the source location within the given node, or `nil` if the
   ///   given syntax node is not rooted in a source file that the macro
   ///   expansion context knows about.
+  @available(*, deprecated, message: "Please use AbstractSourceLocation version")
   func location<Node: SyntaxProtocol>(
     of node: Node,
     at position: PositionInSyntaxNode,
     filePathMode: SourceLocationFilePathMode
   ) -> SourceLocation?
+
+  /// Retrieve a source location for the given syntax node.
+  ///
+  /// - Parameters:
+  ///   - node: The syntax node whose source location to produce.
+  ///   - position: The position within the syntax node for the resulting
+  ///     location.
+  ///   - filePathMode: How the file name contained in the source location is
+  ///     formed.
+  ///
+  /// - Returns: the source location within the given node, or `nil` if the
+  ///   given syntax node is not rooted in a source file that the macro
+  ///   expansion context knows about.
+  @_disfavoredOverload
+  func location<Node: SyntaxProtocol>(
+    of node: Node,
+    at position: PositionInSyntaxNode,
+    filePathMode: SourceLocationFilePathMode
+  ) -> AbstractSourceLocation?
 }
 
 extension MacroExpansionContext {
@@ -58,11 +79,64 @@ extension MacroExpansionContext {
   /// - Returns: the source location within the given node, or `nil` if the
   ///   given syntax node is not rooted in a source file that the macro
   ///   expansion context knows about.
+  @available(*, deprecated, message: "Please use AbstractSourceLocation version")
   public func location<Node: SyntaxProtocol>(
     of node: Node
   ) -> SourceLocation? {
     return location(of: node, at: .afterLeadingTrivia, filePathMode: .fileID)
   }
+
+  /// Retrieve a source location for the given syntax node's starting token
+  /// (after leading trivia) using file naming according to `#fileID`.
+  ///
+  /// - Parameters:
+  ///   - node: The syntax node whose source location to produce.
+  ///
+  /// - Returns: the source location within the given node, or `nil` if the
+  ///   given syntax node is not rooted in a source file that the macro
+  ///   expansion context knows about.
+  @_disfavoredOverload
+  public func location<Node: SyntaxProtocol>(
+    of node: Node
+  ) -> AbstractSourceLocation? {
+    return location(of: node, at: .afterLeadingTrivia, filePathMode: .fileID)
+  }
+}
+
+extension MacroExpansionContext {
+  /// Retrieve a source location for the given syntax node.
+  ///
+  /// - Parameters:
+  ///   - node: The syntax node whose source location to produce.
+  ///   - position: The position within the syntax node for the resulting
+  ///     location.
+  ///   - filePathMode: How the file name contained in the source location is
+  ///     formed.
+  ///
+  /// - Returns: the source location within the given node, or `nil` if the
+  ///   given syntax node is not rooted in a source file that the macro
+  ///   expansion context knows about.
+  @_disfavoredOverload
+  @available(*, deprecated, message: "Please use AbstractSourceLocation version")
+  public func location<Node: SyntaxProtocol>(
+    of node: Node,
+    at position: PositionInSyntaxNode,
+    filePathMode: SourceLocationFilePathMode
+  ) -> AbstractSourceLocation? {
+    guard let sourceLoc: SourceLocation = location(of: node, at: position, filePathMode: filePathMode),
+      let file = sourceLoc.file,
+      let line = sourceLoc.line,
+      let column = sourceLoc.column
+    else {
+      return nil
+    }
+
+    return AbstractSourceLocation(
+      file: "\(literal: file)",
+      line: "\(literal: line)",
+      column: "\(literal: column)"
+    )
+  }
 }
 
 /// Diagnostic message used for thrown errors.

Tests/SwiftSyntaxMacrosTest/MacroSystemTests.swift

@@ -130,17 +130,15 @@ public struct ColumnMacro: ExpressionMacro {
     of macro: Node,
     in context: Context
   ) throws -> ExprSyntax {
-    guard let sourceLoc = context.location(of: macro),
-      let column = sourceLoc.column
+    guard let sourceLoc: AbstractSourceLocation = context.location(of: macro)
     else {
       throw CustomError.message("can't find location for macro")
     }
 
-    let fileLiteral: ExprSyntax = "\(literal: column)"
     if let leadingTrivia = macro.leadingTrivia {
-      return fileLiteral.with(\.leadingTrivia, leadingTrivia)
+      return sourceLoc.column.with(\.leadingTrivia, leadingTrivia)
     }
-    return fileLiteral
+    return sourceLoc.column
   }
 }
 
@@ -152,17 +150,15 @@ public struct FileIDMacro: ExpressionMacro {
     of macro: Node,
     in context: Context
   ) throws -> ExprSyntax {
-    guard let sourceLoc = context.location(of: macro),
-      let fileID = sourceLoc.file
+    guard let sourceLoc: AbstractSourceLocation = context.location(of: macro)
     else {
       throw CustomError.message("can't find location for macro")
     }
 
-    let fileLiteral: ExprSyntax = "\(literal: fileID)"
     if let leadingTrivia = macro.leadingTrivia {
-      return fileLiteral.with(\.leadingTrivia, leadingTrivia)
+      return sourceLoc.file.with(\.leadingTrivia, leadingTrivia)
     }
-    return fileLiteral
+    return sourceLoc.file
   }
 }