Add support for -disable-upcoming-feature and -disable-experimental-feature.

Synchronize Options.swift with swiftlang/swift#77662
and update the driver to pass all feature related flags down to the frontend
together, preserving the order the flags were specified.

Author: tshortli

Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift

@@ -52,6 +52,14 @@ extension Driver {
     case computed
   }
 
+  /// If the given option is specified but the frontend doesn't support it, throw an error.
+  func verifyFrontendSupportsOptionIfNecessary(_ option: Option) throws {
+    if parsedOptions.hasArgument(option) && !isFrontendArgSupported(option) {
+      diagnosticEngine.emit(.error_unsupported_opt_for_frontend(option: option))
+      throw ErrorDiagnostics.emitted
+    }
+  }
+
   /// Add frontend options that are common to different frontend invocations.
   mutating func addCommonFrontendOptions(
     commandLine: inout [Job.ArgTemplate],
@@ -154,6 +162,9 @@ extension Driver {
       throw ErrorDiagnostics.emitted
     }
 
+    try verifyFrontendSupportsOptionIfNecessary(.disableUpcomingFeature)
+    try verifyFrontendSupportsOptionIfNecessary(.disableExperimentalFeature)
+
     // Handle the CPU and its preferences.
     try commandLine.appendLast(.targetCpu, from: &parsedOptions)
 
@@ -275,14 +286,11 @@ extension Driver {
     if isFrontendArgSupported(.compilerAssertions) {
       try commandLine.appendLast(.compilerAssertions, from: &parsedOptions)
     }
-    if isFrontendArgSupported(.enableExperimentalFeature) {
-      try commandLine.appendAll(
-        .enableExperimentalFeature, from: &parsedOptions)
-    }
-    if isFrontendArgSupported(.enableUpcomingFeature) {
-      try commandLine.appendAll(
-        .enableUpcomingFeature, from: &parsedOptions)
-    }
+    try commandLine.appendAll(.enableExperimentalFeature,
+                              .disableExperimentalFeature,
+                              .enableUpcomingFeature,
+                              .disableUpcomingFeature,
+                              from: &parsedOptions)
     try commandLine.appendAll(.moduleAlias, from: &parsedOptions)
     if isFrontendArgSupported(.enableBareSlashRegex) {
       try commandLine.appendLast(.enableBareSlashRegex, from: &parsedOptions)

Sources/SwiftDriver/Utilities/Diagnostics.swift

@@ -35,6 +35,10 @@ extension Diagnostic.Message {
     .error("unsupported argument '\(argument)' to option '\(option.spelling)'")
   }
 
+  static func error_unsupported_opt_for_frontend(option: Option) -> Diagnostic.Message {
+    .error("frontend does not support option '\(option.spelling)'")
+  }
+
   static func error_option_requires_sanitizer(option: Option) -> Diagnostic.Message {
     .error("option '\(option.spelling)' requires a sanitizer to be enabled. Use -sanitize= to enable a sanitizer")
   }

Sources/SwiftOptions/Options.swift

@@ -184,6 +184,7 @@ extension Option {
   public static let disableDynamicActorIsolation: Option = Option("-disable-dynamic-actor-isolation", .flag, attributes: [.frontend, .doesNotAffectIncrementalBuild], helpText: "Disable dynamic actor isolation checks")
   public static let disableEmitGenericClassRoTList: Option = Option("-disable-emit-generic-class-ro_t-list", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable emission of a section with references to class_ro_t of generic class patterns")
   public static let disableExperimentalClangImporterDiagnostics: Option = Option("-disable-experimental-clang-importer-diagnostics", .flag, attributes: [.helpHidden, .frontend, .noDriver, .moduleInterface], helpText: "Disable experimental diagnostics when importing C, C++, and Objective-C libraries")
+  public static let disableExperimentalFeature: Option = Option("-disable-experimental-feature", .separate, attributes: [.frontend, .moduleInterface], helpText: "Disable an experimental feature")
   public static let disableExperimentalLifetimeDependenceInference: Option = Option("-disable-experimental-lifetime-dependence-inference", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable experimental lifetime dependence inference")
   public static let disableExperimentalOpenedExistentialTypes: Option = Option("-disable-experimental-opened-existential-types", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable experimental support for implicitly opened existentials")
   public static let disableExperimentalParserRoundTrip: Option = Option("-disable-experimental-parser-round-trip", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable round trip through the new swift parser")
@@ -263,6 +264,7 @@ extension Option {
   public static let disableThrowsPrediction: Option = Option("-disable-throws-prediction", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disables optimization assumption that functions rarely throw errors.")
   public static let disableTypeLayouts: Option = Option("-disable-type-layout", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable type layout based lowering")
   public static let disableTypoCorrection: Option = Option("-disable-typo-correction", .flag, attributes: [.frontend, .noDriver], helpText: "Disable typo correction")
+  public static let disableUpcomingFeature: Option = Option("-disable-upcoming-feature", .separate, attributes: [.frontend, .moduleInterface], helpText: "Disable a feature that will be introduced in an upcoming language version")
   public static let disableVerifyExclusivity: Option = Option("-disable-verify-exclusivity", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable verification of access markers used to enforce exclusivity.")
   public static let disallowForwardingDriver: Option = Option("-disallow-use-new-driver", .flag, helpText: "Disable using new swift-driver")
   public static let downgradeTypecheckInterfaceError: Option = Option("-downgrade-typecheck-interface-error", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Downgrade error to warning when typechecking emitted module interfaces")
@@ -1087,6 +1089,7 @@ extension Option {
       Option.disableDynamicActorIsolation,
       Option.disableEmitGenericClassRoTList,
       Option.disableExperimentalClangImporterDiagnostics,
+      Option.disableExperimentalFeature,
       Option.disableExperimentalLifetimeDependenceInference,
       Option.disableExperimentalOpenedExistentialTypes,
       Option.disableExperimentalParserRoundTrip,
@@ -1166,6 +1169,7 @@ extension Option {
       Option.disableThrowsPrediction,
       Option.disableTypeLayouts,
       Option.disableTypoCorrection,
+      Option.disableUpcomingFeature,
       Option.disableVerifyExclusivity,
       Option.disallowForwardingDriver,
       Option.downgradeTypecheckInterfaceError,

Tests/SwiftDriverTests/SwiftDriverTests.swift

@@ -8295,6 +8295,45 @@ final class SwiftDriverTests: XCTestCase {
       XCTAssertTrue(!jobs[0].commandLine.contains("-emit-irgen"))
     }
   }
+
+  func testEnableFeatures() throws {
+    do {
+      let featureArgs = [
+        "-enable-upcoming-feature", "MemberImportVisibility",
+        "-enable-experimental-feature", "ParserValidation",
+        "-enable-upcoming-feature", "ConcisePoundFile",
+      ]
+      var driver = try Driver(args: ["swiftc", "file.swift"] + featureArgs)
+      let jobs = try driver.planBuild().removingAutolinkExtractJobs()
+      XCTAssertEqual(jobs.count, 2)
+
+      // Verify that the order of both upcoming and experimental features is preserved.
+      XCTAssertTrue(jobs[0].commandLine.contains(subsequence: featureArgs.map { Job.ArgTemplate.flag($0) }))
+    }
+  }
+
+  func testDisableFeatures() throws {
+    let driver = try Driver(args: ["swiftc", "foo.swift"])
+    guard driver.isFrontendArgSupported(.disableUpcomingFeature) else {
+      throw XCTSkip("Skipping: compiler does not support '-disable-upcoming-feature'")
+    }
+
+    do {
+      let featureArgs = [
+        "-enable-upcoming-feature", "MemberImportVisibility",
+        "-disable-upcoming-feature", "MemberImportVisibility",
+        "-disable-experimental-feature", "ParserValidation",
+        "-enable-experimental-feature", "ParserValidation",
+      ]
+
+      var driver = try Driver(args: ["swiftc", "file.swift"] + featureArgs)
+      let jobs = try driver.planBuild().removingAutolinkExtractJobs()
+      XCTAssertEqual(jobs.count, 2)
+
+      // Verify that the order of both upcoming and experimental features is preserved.
+      XCTAssertTrue(jobs[0].commandLine.contains(subsequence: featureArgs.map { Job.ArgTemplate.flag($0) }))
+    }
+  }
 }
 
 func assertString(