[Macros] Accept "freeStandingDeclaration" as 'MacroRole.declaration'

Examples/Sources/ExamplePlugin/ExamplePlugin.swift

@@ -5,6 +5,12 @@ import SwiftSyntaxMacros
 struct ThePlugin: CompilerPlugin {
   var providingMacros: [Macro.Type] = [
     EchoExpressionMacro.self,
+    FuncUniqueMacro.self,
     MetadataMacro.self,
+    PeerValueWithSuffixNameMacro.self,
+    MemberDeprecatedMacro.self,
+    EquatableConformanceMacro.self,
+    DidSetPrintMacro.self,
+    PrintAnyMacro.self,
   ]
 }

Examples/Sources/ExamplePlugin/Macros.swift

@@ -16,6 +16,17 @@ struct EchoExpressionMacro: ExpressionMacro {
   }
 }
 
+/// Func With unique name.
+struct FuncUniqueMacro: DeclarationMacro {
+  static func expansion(
+    of node: some FreestandingMacroExpansionSyntax,
+    in context: some MacroExpansionContext
+  ) throws -> [DeclSyntax] {
+    let name = context.makeUniqueName("unique")
+    return ["func \(name)() {}"]
+  }
+}
+
 /// Add a static property `__metadata__`.
 struct MetadataMacro: MemberMacro {
   static func expansion<
@@ -26,14 +37,81 @@ struct MetadataMacro: MemberMacro {
     providingMembersOf declaration: Declaration,
     in context: Context
   ) throws -> [DeclSyntax] {
-    guard let cls = declaration.as(ClassDeclSyntax.self) else {
+    guard let type = declaration.asProtocol(IdentifiedDeclSyntax.self) else {
       return []
     }
-    let className = cls.identifier.trimmedDescription
+    let typeName = type.identifier.trimmedDescription
     return [
       """
-      static var __metadata__: [String: String] { ["name": "\(raw: className)"] }
+      static var __metadata__: [String: String] { ["name": "\(raw: typeName)"] }
       """
     ]
   }
 }
+
+/// Peer 'var' with the name suffixed with '_peer'.
+struct PeerValueWithSuffixNameMacro: PeerMacro {
+  static func expansion(
+    of node: AttributeSyntax,
+    providingPeersOf declaration: some DeclSyntaxProtocol,
+    in context: some MacroExpansionContext
+  ) throws -> [DeclSyntax] {
+    guard let identified = declaration.asProtocol(IdentifiedDeclSyntax.self) else {
+      return []
+    }
+    return ["var \(raw: identified.identifier.text)_peer: Int { 1 }"]
+  }
+}
+
+/// Add '@available(*, deprecated)' to members.
+struct MemberDeprecatedMacro: MemberAttributeMacro {
+  static func expansion(
+    of node: SwiftSyntax.AttributeSyntax,
+    attachedTo declaration: some SwiftSyntax.DeclGroupSyntax,
+    providingAttributesFor member: some SwiftSyntax.DeclSyntaxProtocol,
+    in context: some SwiftSyntaxMacros.MacroExpansionContext
+  ) throws -> [SwiftSyntax.AttributeSyntax] {
+    return ["@available(*, deprecated)"]
+  }
+}
+
+/// Add 'Equatable' conformance.
+struct EquatableConformanceMacro: ConformanceMacro {
+  static func expansion(
+    of node: AttributeSyntax,
+    providingConformancesOf declaration: some DeclGroupSyntax,
+    in context: some MacroExpansionContext
+  ) throws -> [(TypeSyntax, GenericWhereClauseSyntax?)] {
+    return [("Equatable", nil)]
+  }
+}
+
+/// Add 'didSet' printing the new value.
+struct DidSetPrintMacro: AccessorMacro {
+  static func expansion(
+    of node: AttributeSyntax,
+    providingAccessorsOf declaration: some DeclSyntaxProtocol,
+    in context: some MacroExpansionContext
+  ) throws -> [AccessorDeclSyntax] {
+    guard
+      let identifier = declaration.as(VariableDeclSyntax.self)?.bindings.first?.pattern.as(IdentifierPatternSyntax.self)?.identifier
+    else {
+      return []
+    }
+
+    return ["didSet { print(\(identifier)) }"]
+  }
+}
+
+/// 'print(<arg>)'.
+struct PrintAnyMacro: CodeItemMacro {
+  static func expansion(
+    of node: some FreestandingMacroExpansionSyntax,
+    in context: some MacroExpansionContext
+  ) throws -> [CodeBlockItemSyntax] {
+    guard let expr = node.argumentList.first?.expression else {
+      return []
+    }
+    return ["print(\(expr))"]
+  }
+}

Sources/SwiftCompilerPluginMessageHandling/PluginMessageCompatibility.swift

@@ -0,0 +1,33 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 2023 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+/// Old compiler might send '.declaration' as "freeStandingDeclaration".
+extension PluginMessage.MacroRole {
+  init(from decoder: Decoder) throws {
+    let stringValue = try decoder.singleValueContainer().decode(String.self)
+    if let role = Self(rawValue: stringValue) {
+      self = role
+      return
+    }
+    // Accept "freeStandingDeclaration" as '.declaration'.
+    if stringValue == "freeStandingDeclaration" {
+      self = Self.declaration
+      return
+    }
+    throw DecodingError.dataCorrupted(
+      DecodingError.Context(
+        codingPath: decoder.codingPath,
+        debugDescription: "Invalid string value for MacroRole: \(stringValue)"
+      )
+    )
+  }
+}

lit_tests/compiler_plugin_basic.swift

@@ -2,30 +2,105 @@
 //
 // RUN: %empty-directory(%t)
 //
-// RUN: %swift-frontend -typecheck -swift-version 5 \
-// RUN:   -enable-experimental-feature Macros \
+// RUN: %swift-frontend -typecheck -verify -swift-version 5 \
+// RUN:   -enable-experimental-feature CodeItemMacros \
 // RUN:   -dump-macro-expansions \
 // RUN:   -load-plugin-executable %examples_bin_path/ExamplePlugin#ExamplePlugin \
-// RUN    -module-name MyApp \
+// RUN:   -parse-as-library \
+// RUN:   -module-name TestApp \
 // RUN:   %s 2>&1 | tee %t/expansions-dump.txt
 //
 // RUN: %FileCheck %s < %t/expansions-dump.txt
 
 @freestanding(expression)
 macro echo<T>(_: T) -> T = #externalMacro(module: "ExamplePlugin", type: "EchoExpressionMacro")
 
+@freestanding(declaration)
+macro funcUnique() = #externalMacro(module: "ExamplePlugin", type: "FuncUniqueMacro")
+
+@freestanding(codeItem)
+macro printAny(_: Any) = #externalMacro(module: "ExamplePlugin", type: "PrintAnyMacro")
+
 @attached(member, names: named(__metadata__))
 macro Metadata() = #externalMacro(module: "ExamplePlugin", type: "MetadataMacro")
 
+@attached(peer, names: suffixed(_peer))
+macro PeerWithSuffix() = #externalMacro(module: "ExamplePlugin", type: "PeerValueWithSuffixNameMacro")
+
+@attached(memberAttribute)
+macro MemberDeprecated() = #externalMacro(module: "ExamplePlugin", type: "MemberDeprecatedMacro")
+
+@attached(conformance)
+macro Equatable() = #externalMacro(module: "ExamplePlugin", type: "EquatableConformanceMacro")
+
+@attached(accessor)
+macro DidSetPrint() = #externalMacro(module: "ExamplePlugin", type: "DidSetPrintMacro")
+
 @Metadata
-class MyClass {
+@MemberDeprecated
+@Equatable
+@PeerWithSuffix
+struct MyStruct {
+  @DidSetPrint
   var value: Int = #echo(12)
+  // expected-error@-1 {{expansion of macro 'DidSetPrint()' did not produce a non-observing accessor}}
+
+  func _test() {
+    #printAny("test")
+  }
 }
 
-// For '@Metadata'
-// CHECK: {{^}}static var __metadata__: [String: String] {
-// CHECK-NEXT: {{^}}    ["name": "MyClass"]
-// CHECK-NEXT: {{^}}}
+#funcUnique
+
+// CHECK: @__swiftmacro_7TestApp8MyStruct14PeerWithSuffixfMp_.swift
+// CHECK-NEXT: ------------------------------
+// CHECK-NEXT: var MyStruct_peer: Int {
+// CHECK-NEXT:     1
+// CHECK-NEXT: }
+// CHECK-NEXT: ------------------------------
+
+// CHECK: @__swiftmacro_7TestApp8MyStruct9EquatablefMc_.swift
+// CHECK-NEXT: ------------------------------
+// CHECK-NEXT: extension MyStruct : Equatable  {}
+// CHECK-NEXT: ------------------------------
+
+// CHECK: @__swiftmacro_7TestApp8MyStruct8MetadatafMm_.swift
+// CHECK-NEXT: ------------------------------
+// CHECK-NEXT: static var __metadata__: [String: String] {
+// CHECK-NEXT:     ["name": "MyStruct"]
+// CHECK-NEXT: }
+// CHECK-NEXT: ------------------------------
+
+// CHECK: @__swiftmacro_7TestApp8MyStructV5value16MemberDeprecatedfMr_.swift
+// CHECK-NEXT: ------------------------------
+// CHECK-NEXT: @available(*, deprecated)
+// CHECK-NEXT: ------------------------------
+
+// CHECK: @__swiftmacro_7TestApp8MyStructV5_test16MemberDeprecatedfMr0_.swift
+// CHECK-NEXT: ------------------------------
+// CHECK-NEXT: @available(*, deprecated)
+// CHECK-NEXT: ------------------------------
+
+// CHECK: @__swiftmacro_7TestApp8MyStructV5value11DidSetPrintfMa_.swift
+// CHECK-NEXT: ------------------------------
+// CHECK-NEXT: {
+// CHECK-NEXT:     didSet {
+// CHECK-NEXT:         print(value)
+// CHECK-NEXT:     }
+// CHECK-NEXT: }
+// CHECK-NEXT: ------------------------------
+
+// CHECK: @__swiftmacro_7TestApp8MyStructV4echofMf_.swift
+// CHECK-NEXT: ------------------------------
+// CHECK-NEXT: /* echo */12
+// CHECK-NEXT: ------------------------------
+
+// CHECK: @__swiftmacro_7TestApp33_B5E4CA48BE2C4AA1BE7F954C809E362ALl10funcUniquefMf_.swift
+// CHECK-NEXT: ------------------------------
+// CHECK-NEXT: func $s7TestApp33_B5E4CA48BE2C4AA1BE7F954C809E362ALl10funcUniquefMf_6uniquefMu_() {
+// CHECK-NEXT: }
 
-// For '#echo(12)'
-// CHECK: /* echo */12
+// CHECK: @__swiftmacro_7TestApp8MyStructV5_testyyF8printAnyfMf0_.swift
+// CHECK-NEXT: ------------------------------
+// CHECK-NEXT: print("test")
+// CHECK-NEXT: ------------------------------