Enforce any on existential types (#5273)

This makes syntactically clear which types are rather expensive.

.sourcery/BuiltInRules.stencil

@@ -1,5 +1,5 @@
 
 /// The rule list containing all available rules built into SwiftLint.
-public let builtInRules: [Rule.Type] = [
+public let builtInRules: [any Rule.Type] = [
 {% for rule in types.structs where rule.name|hasSuffix:"Rule" %}    {{ rule.name }}.self{% if not forloop.last %},{% endif %}
 {% endfor %}]

.sourcery/ReportersList.stencil

@@ -1,6 +1,6 @@
 
 /// The reporters list containing all the reporters built into SwiftLint.
-public let reportersList: [Reporter.Type] = [
+public let reportersList: [any Reporter.Type] = [
 {% for reporter in types.structs where reporter.name|hasSuffix:"Reporter" %}
     {{ reporter.name }}.self{% if not forloop.last %},{% endif %}
 {% endfor %}

BUILD

@@ -6,6 +6,8 @@ load(
     "swift_compiler_plugin"
 )
 
+copts = ["-enable-upcoming-feature", "ExistentialAny"]
+
 # Targets
 
 swift_library(
@@ -17,6 +19,7 @@ swift_library(
         "@SwiftSyntax//:SwiftCompilerPlugin_opt",
         "@SwiftSyntax//:SwiftSyntaxMacros_opt",
     ],
+    copts = copts,
 )
 
 swift_compiler_plugin(
@@ -26,6 +29,7 @@ swift_compiler_plugin(
         "@SwiftSyntax//:SwiftCompilerPlugin_opt",
         "@SwiftSyntax//:SwiftSyntaxMacros_opt",
     ],
+    copts = copts,
 )
 
 swift_library(
@@ -49,6 +53,7 @@ swift_library(
     plugins = [
         ":SwiftLintCoreMacros",
     ],
+    copts = copts,
 )
 
 swift_library(
@@ -59,6 +64,7 @@ swift_library(
     deps = [
         ":SwiftLintCore",
     ],
+    copts = copts,
 )
 
 swift_library(
@@ -86,6 +92,7 @@ swift_library(
         ":SwiftLintCore",
         ":SwiftLintExtraRules",
     ],
+    copts = copts,
 )
 
 swift_library(
@@ -99,6 +106,7 @@ swift_library(
         "@sourcekitten_com_github_apple_swift_argument_parser//:ArgumentParser",
         "@swiftlint_com_github_scottrhoyt_swifty_text_table//:SwiftyTextTable",
     ],
+    copts = copts,
 )
 
 swift_binary(
@@ -107,6 +115,7 @@ swift_binary(
     deps = [
         ":swiftlint.library",
     ],
+    copts = copts,
 )
 
 apple_universal_binary(

Package.swift

@@ -2,6 +2,10 @@
 import CompilerPluginSupport
 import PackageDescription
 
+let swiftFeatures: [SwiftSetting] = [
+    .enableUpcomingFeature("ExistentialAny")
+]
+
 let package = Package(
     name: "SwiftLint",
     platforms: [.macOS(.v12)],
@@ -35,13 +39,15 @@ let package = Package(
                 "CollectionConcurrencyKit",
                 "SwiftLintFramework",
                 "SwiftyTextTable",
-            ]
+            ],
+            swiftSettings: swiftFeatures
         ),
         .testTarget(
             name: "CLITests",
             dependencies: [
                 "swiftlint"
-            ]
+            ],
+            swiftSettings: swiftFeatures
         ),
         .target(
             name: "SwiftLintCore",
@@ -57,11 +63,13 @@ let package = Package(
                 .product(name: "SwiftyTextTable", package: "SwiftyTextTable"),
                 .product(name: "Yams", package: "Yams"),
                 "SwiftLintCoreMacros"
-            ]
+            ],
+            swiftSettings: swiftFeatures
         ),
         .target(
             name: "SwiftLintBuiltInRules",
-            dependencies: ["SwiftLintCore"]
+            dependencies: ["SwiftLintCore"],
+            swiftSettings: swiftFeatures
         ),
         .target(
             name: "SwiftLintExtraRules",
@@ -76,7 +84,8 @@ let package = Package(
                 // Workaround for https://github.com/apple/swift-package-manager/issues/6940:
                 .product(name: "ArgumentParser", package: "swift-argument-parser"),
                 "CollectionConcurrencyKit"
-            ]
+            ],
+            swiftSettings: swiftFeatures
         ),
         .target(name: "DyldWarningWorkaround"),
         .target(
@@ -95,21 +104,24 @@ let package = Package(
             ],
             exclude: [
                 "Resources",
-            ]
+            ],
+            swiftSettings: swiftFeatures
         ),
         .testTarget(
             name: "GeneratedTests",
             dependencies: [
                 "SwiftLintFramework",
                 "SwiftLintTestHelpers"
-            ]
+            ],
+            swiftSettings: swiftFeatures
         ),
         .testTarget(
             name: "IntegrationTests",
             dependencies: [
                 "SwiftLintFramework",
                 "SwiftLintTestHelpers"
-            ]
+            ],
+            swiftSettings: swiftFeatures
         ),
         .testTarget(
             name: "ExtraRulesTests",
@@ -129,14 +141,16 @@ let package = Package(
                 .product(name: "SwiftSyntaxMacros", package: "swift-syntax"),
                 .product(name: "SwiftCompilerPlugin", package: "swift-syntax")
             ],
-            path: "Source/SwiftLintCoreMacros"
+            path: "Source/SwiftLintCoreMacros",
+            swiftSettings: swiftFeatures
         ),
         .testTarget(
             name: "MacroTests",
             dependencies: [
                 "SwiftLintCoreMacros",
                 .product(name: "SwiftSyntaxMacrosTestSupport", package: "swift-syntax"),
-            ]
+            ],
+            swiftSettings: swiftFeatures
         ),
     ]
 )

Source/SwiftLintBuiltInRules/Models/BuiltInRules.swift

@@ -2,7 +2,7 @@
 // DO NOT EDIT
 
 /// The rule list containing all available rules built into SwiftLint.
-public let builtInRules: [Rule.Type] = [
+public let builtInRules: [any Rule.Type] = [
     AccessibilityLabelForImageRule.self,
     AccessibilityTraitForButtonRule.self,
     AnonymousArgumentInMultilineClosureRule.self,

Source/SwiftLintBuiltInRules/Rules/Idiomatic/ConvenienceTypeRule.swift

@@ -119,7 +119,7 @@ struct ConvenienceTypeRule: OptInRule, ConfigurationProviderRule {
 
 private extension ConvenienceTypeRule {
     final class Visitor: ViolationsSyntaxVisitor {
-        override var skippableDeclarations: [DeclSyntaxProtocol.Type] { [ProtocolDeclSyntax.self] }
+        override var skippableDeclarations: [any DeclSyntaxProtocol.Type] { [ProtocolDeclSyntax.self] }
 
         override func visitPost(_ node: StructDeclSyntax) {
             if hasViolation(
@@ -158,7 +158,7 @@ private extension ConvenienceTypeRule {
 }
 
 private class ConvenienceTypeCheckVisitor: ViolationsSyntaxVisitor {
-    override var skippableDeclarations: [DeclSyntaxProtocol.Type] { .all }
+    override var skippableDeclarations: [any DeclSyntaxProtocol.Type] { .all }
 
     private(set) var canBeConvenienceType = true
 

Source/SwiftLintBuiltInRules/Rules/Idiomatic/ExplicitEnumRawValueRule.swift

@@ -81,7 +81,7 @@ struct ExplicitEnumRawValueRule: OptInRule, ConfigurationProviderRule {
 
 private extension ExplicitEnumRawValueRule {
     final class Visitor: ViolationsSyntaxVisitor {
-        override var skippableDeclarations: [DeclSyntaxProtocol.Type] { [ProtocolDeclSyntax.self] }
+        override var skippableDeclarations: [any DeclSyntaxProtocol.Type] { [ProtocolDeclSyntax.self] }
 
         override func visitPost(_ node: EnumCaseElementSyntax) {
             if node.rawValue == nil, node.enclosingEnum()?.supportsRawValues == true {

Source/SwiftLintBuiltInRules/Rules/Idiomatic/ExplicitInitRule.swift

@@ -173,7 +173,7 @@ struct ExplicitInitRule: SwiftSyntaxCorrectableRule, ConfigurationProviderRule,
         Visitor(viewMode: .sourceAccurate, includeBareInit: configuration.includeBareInit)
     }
 
-    func makeRewriter(file: SwiftLintFile) -> ViolationsSyntaxRewriter? {
+    func makeRewriter(file: SwiftLintFile) -> (some ViolationsSyntaxRewriter)? {
         Rewriter(locationConverter: file.locationConverter, disabledRegions: disabledRegions(file: file))
     }
 }

Source/SwiftLintBuiltInRules/Rules/Idiomatic/ExplicitTopLevelACLRule.swift

@@ -32,7 +32,7 @@ struct ExplicitTopLevelACLRule: OptInRule, ConfigurationProviderRule {
 
 private extension ExplicitTopLevelACLRule {
     final class Visitor: ViolationsSyntaxVisitor {
-        override var skippableDeclarations: [DeclSyntaxProtocol.Type] { .all }
+        override var skippableDeclarations: [any DeclSyntaxProtocol.Type] { .all }
 
         override func visitPost(_ node: ClassDeclSyntax) {
             if hasViolation(modifiers: node.modifiers) {

Source/SwiftLintBuiltInRules/Rules/Idiomatic/ExplicitTypeInterfaceRule.swift

@@ -78,7 +78,7 @@ private extension ExplicitTypeInterfaceRule {
     final class Visitor: ViolationsSyntaxVisitor {
         let configuration: ExplicitTypeInterfaceConfiguration
 
-        override var skippableDeclarations: [DeclSyntaxProtocol.Type] { [ProtocolDeclSyntax.self] }
+        override var skippableDeclarations: [any DeclSyntaxProtocol.Type] { [ProtocolDeclSyntax.self] }
 
         init(configuration: ExplicitTypeInterfaceConfiguration) {
             self.configuration = configuration

Source/SwiftLintBuiltInRules/Rules/Idiomatic/JoinedDefaultParameterRule.swift

@@ -37,7 +37,7 @@ struct JoinedDefaultParameterRule: SwiftSyntaxCorrectableRule, ConfigurationProv
         ]
     )
 
-    func makeRewriter(file: SwiftLintFile) -> ViolationsSyntaxRewriter? {
+    func makeRewriter(file: SwiftLintFile) -> (some ViolationsSyntaxRewriter)? {
         Rewriter(
             locationConverter: file.locationConverter,
             disabledRegions: disabledRegions(file: file)

Source/SwiftLintBuiltInRules/Rules/Idiomatic/LegacyCGGeometryFunctionsRule.swift

@@ -104,7 +104,7 @@ struct LegacyCGGeometryFunctionsRule: SwiftSyntaxCorrectableRule, ConfigurationP
         LegacyFunctionRuleHelper.Visitor(legacyFunctions: Self.legacyFunctions)
     }
 
-    func makeRewriter(file: SwiftLintFile) -> ViolationsSyntaxRewriter? {
+    func makeRewriter(file: SwiftLintFile) -> (some ViolationsSyntaxRewriter)? {
         LegacyFunctionRuleHelper.Rewriter(
             legacyFunctions: Self.legacyFunctions,
             locationConverter: file.locationConverter,

Source/SwiftLintBuiltInRules/Rules/Idiomatic/LegacyConstantRule.swift

@@ -15,7 +15,7 @@ struct LegacyConstantRule: SwiftSyntaxCorrectableRule, ConfigurationProviderRule
         corrections: LegacyConstantRuleExamples.corrections
     )
 
-    func makeRewriter(file: SwiftLintFile) -> ViolationsSyntaxRewriter? {
+    func makeRewriter(file: SwiftLintFile) -> (some ViolationsSyntaxRewriter)? {
         Rewriter(
             locationConverter: file.locationConverter,
             disabledRegions: disabledRegions(file: file)

Source/SwiftLintBuiltInRules/Rules/Idiomatic/LegacyConstructorRule.swift

@@ -123,7 +123,7 @@ struct LegacyConstructorRule: SwiftSyntaxCorrectableRule, ConfigurationProviderR
                                                        "NSEdgeInsetsMake": "NSEdgeInsets",
                                                        "UIOffsetMake": "UIOffset"]
 
-    func makeRewriter(file: SwiftLintFile) -> ViolationsSyntaxRewriter? {
+    func makeRewriter(file: SwiftLintFile) -> (some ViolationsSyntaxRewriter)? {
         Rewriter(
             locationConverter: file.locationConverter,
             disabledRegions: disabledRegions(file: file)

Source/SwiftLintBuiltInRules/Rules/Idiomatic/LegacyNSGeometryFunctionsRule.swift

@@ -104,7 +104,7 @@ struct LegacyNSGeometryFunctionsRule: SwiftSyntaxCorrectableRule, ConfigurationP
         LegacyFunctionRuleHelper.Visitor(legacyFunctions: Self.legacyFunctions)
     }
 
-    func makeRewriter(file: SwiftLintFile) -> ViolationsSyntaxRewriter? {
+    func makeRewriter(file: SwiftLintFile) -> (some ViolationsSyntaxRewriter)? {
         LegacyFunctionRuleHelper.Rewriter(
             legacyFunctions: Self.legacyFunctions,
             locationConverter: file.locationConverter,

Source/SwiftLintBuiltInRules/Rules/Idiomatic/NoExtensionAccessModifierRule.swift

@@ -25,7 +25,7 @@ struct NoExtensionAccessModifierRule: OptInRule, ConfigurationProviderRule {
 
 private extension NoExtensionAccessModifierRule {
     final class Visitor: ViolationsSyntaxVisitor {
-        override var skippableDeclarations: [DeclSyntaxProtocol.Type] { .all }
+        override var skippableDeclarations: [any DeclSyntaxProtocol.Type] { .all }
 
         override func visitPost(_ node: ExtensionDeclSyntax) {
             let modifiers = node.modifiers

Source/SwiftLintBuiltInRules/Rules/Idiomatic/NoMagicNumbersRule.swift

@@ -132,7 +132,7 @@ private extension NoMagicNumbersRule {
             collectViolation(forNode: node)
         }
 
-        private func collectViolation(forNode node: ExprSyntaxProtocol) {
+        private func collectViolation(forNode node: some ExprSyntaxProtocol) {
             if node.isMemberOfATestClass(testParentClasses) {
                 return
             }

Source/SwiftLintBuiltInRules/Rules/Idiomatic/PreferZeroOverExplicitInitRule.swift

@@ -35,7 +35,7 @@ struct PreferZeroOverExplicitInitRule: SwiftSyntaxCorrectableRule, OptInRule, Co
         ]
     )
 
-    func makeRewriter(file: SwiftLintFile) -> ViolationsSyntaxRewriter? {
+    func makeRewriter(file: SwiftLintFile) -> (some ViolationsSyntaxRewriter)? {
         Rewriter(
             locationConverter: file.locationConverter,
             disabledRegions: disabledRegions(file: file)

Source/SwiftLintBuiltInRules/Rules/Idiomatic/PrivateOverFilePrivateRule.swift

@@ -58,7 +58,7 @@ struct PrivateOverFilePrivateRule: ConfigurationProviderRule, SwiftSyntaxCorrect
         Visitor(validateExtensions: configuration.validateExtensions)
     }
 
-    func makeRewriter(file: SwiftLintFile) -> ViolationsSyntaxRewriter? {
+    func makeRewriter(file: SwiftLintFile) -> (some ViolationsSyntaxRewriter)? {
         Rewriter(
             validateExtensions: configuration.validateExtensions,
             locationConverter: file.locationConverter,

Source/SwiftLintBuiltInRules/Rules/Idiomatic/RedundantNilCoalescingRule.swift

@@ -22,7 +22,7 @@ struct RedundantNilCoalescingRule: OptInRule, SwiftSyntaxCorrectableRule, Config
         ]
     )
 
-    func makeRewriter(file: SwiftLintFile) -> ViolationsSyntaxRewriter? {
+    func makeRewriter(file: SwiftLintFile) -> (some ViolationsSyntaxRewriter)? {
         Rewriter(
             locationConverter: file.locationConverter,
             disabledRegions: disabledRegions(file: file)

Source/SwiftLintBuiltInRules/Rules/Idiomatic/RedundantOptionalInitializationRule.swift

@@ -105,7 +105,7 @@ struct RedundantOptionalInitializationRule: SwiftSyntaxCorrectableRule, Configur
             """)
     ]
 
-    func makeRewriter(file: SwiftLintFile) -> ViolationsSyntaxRewriter? {
+    func makeRewriter(file: SwiftLintFile) -> (some ViolationsSyntaxRewriter)? {
         Rewriter(
             locationConverter: file.locationConverter,
             disabledRegions: disabledRegions(file: file)

Source/SwiftLintBuiltInRules/Rules/Idiomatic/RedundantSetAccessControlRule.swift

@@ -62,7 +62,7 @@ struct RedundantSetAccessControlRule: ConfigurationProviderRule {
 
 private extension RedundantSetAccessControlRule {
     final class Visitor: ViolationsSyntaxVisitor {
-        override var skippableDeclarations: [DeclSyntaxProtocol.Type] {
+        override var skippableDeclarations: [any DeclSyntaxProtocol.Type] {
             [FunctionDeclSyntax.self]
         }
 
@@ -120,7 +120,7 @@ private extension SyntaxProtocol {
 
 private extension DeclSyntax {
     var modifiers: DeclModifierListSyntax? {
-        self.asProtocol(WithModifiersSyntax.self)?.modifiers
+        self.asProtocol((any WithModifiersSyntax).self)?.modifiers
     }
 }
 

Source/SwiftLintBuiltInRules/Rules/Idiomatic/ShorthandOptionalBindingRule.swift

@@ -80,7 +80,7 @@ struct ShorthandOptionalBindingRule: OptInRule, SwiftSyntaxCorrectableRule, Conf
         deprecatedAliases: ["if_let_shadowing"]
     )
 
-    func makeRewriter(file: SwiftLintFile) -> ViolationsSyntaxRewriter? {
+    func makeRewriter(file: SwiftLintFile) -> (some ViolationsSyntaxRewriter)? {
         Rewriter(
             locationConverter: file.locationConverter,
             disabledRegions: disabledRegions(file: file)

Source/SwiftLintBuiltInRules/Rules/Idiomatic/StaticOperatorRule.swift

@@ -80,7 +80,7 @@ struct StaticOperatorRule: ConfigurationProviderRule, OptInRule {
 
 private extension StaticOperatorRule {
     final class Visitor: ViolationsSyntaxVisitor {
-        override var skippableDeclarations: [DeclSyntaxProtocol.Type] { .all }
+        override var skippableDeclarations: [any DeclSyntaxProtocol.Type] { .all }
 
         override func visitPost(_ node: FunctionDeclSyntax) {
             if node.isFreeFunction, node.isOperator {

Source/SwiftLintBuiltInRules/Rules/Idiomatic/StrictFilePrivateRule.swift

@@ -185,7 +185,7 @@ private extension StrictFilePrivateRule {
             violations.append(node.positionAfterSkippingLeadingTrivia)
         }
 
-        private func implementedTypesInDecl(of node: SyntaxProtocol?) -> [String] {
+        private func implementedTypesInDecl(of node: (some SyntaxProtocol)?) -> [String] {
             guard let node else {
                 queuedFatalError("Given node is nil. That should not happen.")
             }
@@ -216,7 +216,7 @@ private final class ProtocolCollector: ViolationsSyntaxVisitor {
     private(set) var protocols = [String: [ProtocolRequirementType]]()
     private var currentProtocolName: String = ""
 
-    override var skippableDeclarations: [DeclSyntaxProtocol.Type] { .allExcept(ProtocolDeclSyntax.self) }
+    override var skippableDeclarations: [any DeclSyntaxProtocol.Type] { .allExcept(ProtocolDeclSyntax.self) }
 
     override func visit(_ node: ProtocolDeclSyntax) -> SyntaxVisitorContinueKind {
         currentProtocolName = node.name.text