From faa0a3a1ceb207b9c1c863b974663824185d6afb Mon Sep 17 00:00:00 2001
From: Kabir Oberai <oberai.kabir@gmail.com>
Date: Tue, 16 Apr 2024 01:34:38 -0400
Subject: [PATCH 01/12] Update Options.swift

---
 Sources/SwiftOptions/Options.swift | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/Sources/SwiftOptions/Options.swift b/Sources/SwiftOptions/Options.swift
index cd6e072f6..cd24b73bd 100644
--- a/Sources/SwiftOptions/Options.swift
+++ b/Sources/SwiftOptions/Options.swift
@@ -211,7 +211,9 @@ extension Option {
   public static let disableOnlyOneDependencyFile: Option = Option("-disable-only-one-dependency-file", .flag, attributes: [.doesNotAffectIncrementalBuild], helpText: "Disables incremental build optimization that only produces one dependencies file")
   public static let disableOsChecks: Option = Option("-disable-os-checks", .flag, attributes: [.noDriver], helpText: "Skip OS related diagnostics")
   public static let disableOsChecks_: Option = Option("--disable-os-checks", .flag, alias: Option.disableOsChecks, attributes: [.noDriver], helpText: "Skip OS related diagnostics")
+  public static let disableOssaCompleteLifetimes: Option = Option("-disable-ossa-complete-lifetimes", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Do not require linear OSSA lifetimes after SILGen")
   public static let disableOssaOpts: Option = Option("-disable-ossa-opts", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Don't run SIL OSSA optimization passes.")
+  public static let disableOssaVerifyComplete: Option = Option("-disable-ossa-verify-complete", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Do not verify linear OSSA lifetimes after SILGen")
   public static let disablePlaygroundTransform: Option = Option("-disable-playground-transform", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable playground transformation")
   public static let disablePreallocatedInstantiationCaches: Option = Option("-disable-preallocated-instantiation-caches", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Avoid preallocating metadata instantiation caches in globals")
   public static let disablePreviousImplementationCallsInDynamicReplacements: Option = Option("-disable-previous-implementation-calls-in-dynamic-replacements", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable calling the previous implementation in dynamic replacements")
@@ -219,6 +221,7 @@ extension Option {
   public static let disableReadonlyStaticObjects: Option = Option("-disable-readonly-static-objects", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Avoid allocating static objects in a read-only data section")
   public static let disableReflectionMetadata: Option = Option("-disable-reflection-metadata", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable emission of reflection metadata for nominal types")
   public static let disableReflectionNames: Option = Option("-disable-reflection-names", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable emission of names of stored properties and enum cases inreflection metadata")
+  public static let disableStrictConcurrencyRegionBasedIsolation: Option = Option("-disable-region-based-isolation-with-strict-concurrency", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable region based isolation when running with strict concurrency enabled. Only enabled with asserts")
   public static let disableRelativeProtocolWitnessTables: Option = Option("-disable-relative-protocol-witness-tables", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable relative protocol witness tables")
   public static let disableRemoveDeprecatedCheck: Option = Option("-disable-remove-deprecated-check", .flag, attributes: [.noDriver], helpText: "Skip diagnosing removal of deprecated symbols")
   public static let disableRemoveDeprecatedCheck_: Option = Option("--disable-remove-deprecated-check", .flag, alias: Option.disableRemoveDeprecatedCheck, attributes: [.noDriver], helpText: "Skip diagnosing removal of deprecated symbols")
@@ -304,6 +307,7 @@ extension Option {
   public static let emitDependencies: Option = Option("-emit-dependencies", .flag, attributes: [.frontend, .noInteractive, .supplementaryOutput], helpText: "Emit basic Make-compatible dependencies files")
   public static let emitDigesterBaselinePath: Option = Option("-emit-digester-baseline-path", .separate, attributes: [.noInteractive, .argumentIsPath, .supplementaryOutput], metaVar: "<path>", helpText: "Emit a baseline file for the module to <path> using the API digester")
   public static let emitDigesterBaseline: Option = Option("-emit-digester-baseline", .flag, attributes: [.noInteractive, .supplementaryOutput], helpText: "Emit a baseline file for the module using the API digester")
+  public static let emitEmptyObjectFile: Option = Option("-emit-empty-object-file", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Produce a valid but dummy object file when building a library module")
   public static let emitExecutable: Option = Option("-emit-executable", .flag, attributes: [.noInteractive, .doesNotAffectIncrementalBuild], helpText: "Emit a linked executable", group: .modes)
   public static let emitExtensionBlockSymbols: Option = Option("-emit-extension-block-symbols", .flag, attributes: [.helpHidden, .frontend, .noInteractive, .supplementaryOutput], helpText: "Emit 'swift.extension' symbols for extensions to external types instead of directly associating members and conformances with the extended nominal when generating symbol graphs")
   public static let emitFineGrainedDependencySourcefileDotFiles: Option = Option("-emit-fine-grained-dependency-sourcefile-dot-files", .flag, attributes: [.helpHidden, .frontend], helpText: "Emit dot files for every source file.")
@@ -406,7 +410,6 @@ extension Option {
   public static let enableFragileResilientProtocolWitnesses: Option = Option("-enable-fragile-relative-protocol-tables", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Enable relative protocol witness tables")
   public static let enableImplicitBacktracingModuleImport: Option = Option("-enable-implicit-backtracing-module-import", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Enable the implicit import of the _Backtracing module.")
   public static let enableImplicitDynamic: Option = Option("-enable-implicit-dynamic", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Add 'dynamic' to all declarations")
-  public static let enableImportPtrauthFieldFunctionPointers: Option = Option("-enable-import-ptrauth-field-function-pointers", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Enable import of custom ptrauth qualified field function pointers")
   public static let enableIncrementalImports: Option = Option("-enable-incremental-imports", .flag, attributes: [.frontend], helpText: "Enable cross-module incremental build metadata and driver scheduling for Swift modules")
   public static let enableInferPublicConcurrentValue: Option = Option("-enable-infer-public-sendable", .flag, attributes: [.frontend, .noDriver], helpText: "Enable inference of Sendable conformances for public structs and enums")
   public static let enableInvalidEphemeralnessAsError: Option = Option("-enable-invalid-ephemeralness-as-error", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Diagnose invalid ephemeral to non-ephemeral conversions as errors")
@@ -432,6 +435,7 @@ extension Option {
   public static let enableOperatorDesignatedTypes: Option = Option("-enable-operator-designated-types", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Enable operator designated types")
   public static let enableOssaCompleteLifetimes: Option = Option("-enable-ossa-complete-lifetimes", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Require linear OSSA lifetimes after SILGen")
   public static let enableOssaModules: Option = Option("-enable-ossa-modules", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Always serialize SIL in ossa form. If this flag is not passed in, when optimizing ownership will be lowered before serializing SIL")
+  public static let enableOssaVerifyComplete: Option = Option("-enable-ossa-verify-complete", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Verify linear OSSA lifetimes after SILGen")
   public static let enablePackMetadataStackPromotion: Option = Option("-enable-pack-metadata-stack-promotion=", .joined, attributes: [.helpHidden, .frontend, .noDriver], metaVar: "true|false", helpText: "Whether to skip heapifying stack metadata packs when possible.")
   public static let enablePackMetadataStackPromotionNoArg: Option = Option("-enable-pack-metadata-stack-promotion", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Skip heapifying stack metadata packs when possible.")
   public static let enablePrivateImports: Option = Option("-enable-private-imports", .flag, attributes: [.helpHidden, .frontend, .noInteractive], helpText: "Allows this module's internal and private API to be accessed")
@@ -830,7 +834,7 @@ extension Option {
   public static let vfsoverlayEQ: Option = Option("-vfsoverlay=", .joined, alias: Option.vfsoverlay)
   public static let vfsoverlay: Option = Option("-vfsoverlay", .joinedOrSeparate, attributes: [.frontend, .argumentIsPath], helpText: "Add directory to VFS overlay file")
   public static let visualcToolsRoot: Option = Option("-visualc-tools-root", .separate, attributes: [.frontend, .argumentIsPath], metaVar: "<root>", helpText: "VisualC++ Tools Root")
-  public static let visualcToolsVersion: Option = Option("-visualc-tools-version", .separate, attributes: [.frontend,], metaVar: "<version>", helpText: "VisualC++ ToolSet Version")
+  public static let visualcToolsVersion: Option = Option("-visualc-tools-version", .separate, attributes: [.frontend], metaVar: "<version>", helpText: "VisualC++ ToolSet Version")
   public static let v: Option = Option("-v", .flag, attributes: [.doesNotAffectIncrementalBuild], helpText: "Show commands to run and use verbose output")
   public static let warnConcurrency: Option = Option("-warn-concurrency", .flag, attributes: [.frontend, .doesNotAffectIncrementalBuild], helpText: "Warn about code that is unsafe according to the Swift Concurrency model and will become ill-formed in a future language version")
   public static let warnImplicitOverrides: Option = Option("-warn-implicit-overrides", .flag, attributes: [.frontend, .doesNotAffectIncrementalBuild], helpText: "Warn about implicit overrides of protocol members")
@@ -844,6 +848,7 @@ extension Option {
   public static let warnSwift3ObjcInferenceMinimal: Option = Option("-warn-swift3-objc-inference-minimal", .flag, attributes: [.helpHidden, .frontend, .doesNotAffectIncrementalBuild], helpText: "Deprecated, has no effect")
   public static let warnSwift3ObjcInference: Option = Option("-warn-swift3-objc-inference", .flag, alias: Option.warnSwift3ObjcInferenceComplete, attributes: [.helpHidden, .frontend, .doesNotAffectIncrementalBuild])
   public static let warningsAsErrors: Option = Option("-warnings-as-errors", .flag, attributes: [.frontend], helpText: "Treat warnings as errors")
+  public static let wasmPluginServerPath: Option = Option("-wasm-plugin-server-path", .separate, attributes: [.frontend, .noDriver], metaVar: "<path>", helpText: "Path to the swift-wasm-plugin-server executable")
   public static let weakLinkAtTarget: Option = Option("-weak-link-at-target", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Weakly link symbols for declarations that were introduced at the deployment target. Symbols introduced before the deployment target are still strongly linked.")
   public static let wholeModuleOptimization: Option = Option("-whole-module-optimization", .flag, attributes: [.frontend, .noInteractive], helpText: "Optimize input files together instead of individually")
   public static let windowsSdkRoot: Option = Option("-windows-sdk-root", .separate, attributes: [.frontend, .argumentIsPath], metaVar: "<root>", helpText: "Windows SDK Root")
@@ -1055,7 +1060,9 @@ extension Option {
       Option.disableOnlyOneDependencyFile,
       Option.disableOsChecks,
       Option.disableOsChecks_,
+      Option.disableOssaCompleteLifetimes,
       Option.disableOssaOpts,
+      Option.disableOssaVerifyComplete,
       Option.disablePlaygroundTransform,
       Option.disablePreallocatedInstantiationCaches,
       Option.disablePreviousImplementationCallsInDynamicReplacements,
@@ -1063,6 +1070,7 @@ extension Option {
       Option.disableReadonlyStaticObjects,
       Option.disableReflectionMetadata,
       Option.disableReflectionNames,
+      Option.disableStrictConcurrencyRegionBasedIsolation,
       Option.disableRelativeProtocolWitnessTables,
       Option.disableRemoveDeprecatedCheck,
       Option.disableRemoveDeprecatedCheck_,
@@ -1148,6 +1156,7 @@ extension Option {
       Option.emitDependencies,
       Option.emitDigesterBaselinePath,
       Option.emitDigesterBaseline,
+      Option.emitEmptyObjectFile,
       Option.emitExecutable,
       Option.emitExtensionBlockSymbols,
       Option.emitFineGrainedDependencySourcefileDotFiles,
@@ -1250,7 +1259,6 @@ extension Option {
       Option.enableFragileResilientProtocolWitnesses,
       Option.enableImplicitBacktracingModuleImport,
       Option.enableImplicitDynamic,
-      Option.enableImportPtrauthFieldFunctionPointers,
       Option.enableIncrementalImports,
       Option.enableInferPublicConcurrentValue,
       Option.enableInvalidEphemeralnessAsError,
@@ -1276,6 +1284,7 @@ extension Option {
       Option.enableOperatorDesignatedTypes,
       Option.enableOssaCompleteLifetimes,
       Option.enableOssaModules,
+      Option.enableOssaVerifyComplete,
       Option.enablePackMetadataStackPromotion,
       Option.enablePackMetadataStackPromotionNoArg,
       Option.enablePrivateImports,
@@ -1688,6 +1697,7 @@ extension Option {
       Option.warnSwift3ObjcInferenceMinimal,
       Option.warnSwift3ObjcInference,
       Option.warningsAsErrors,
+      Option.wasmPluginServerPath,
       Option.weakLinkAtTarget,
       Option.wholeModuleOptimization,
       Option.windowsSdkRoot,

From d9e3c31360c3ee315529e5f3c81351326134e252 Mon Sep 17 00:00:00 2001
From: Kabir Oberai <oberai.kabir@gmail.com>
Date: Tue, 16 Apr 2024 01:35:08 -0400
Subject: [PATCH 02/12] Pass wasm-plugin-server-path to frontend

---
 .../SwiftDriver/Jobs/FrontendJobHelpers.swift   | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift b/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
index 89dedeb32..a21043c1a 100644
--- a/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
+++ b/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
@@ -488,6 +488,11 @@ extension Driver {
 
       commandLine.appendFlag(.pluginPath)
       commandLine.appendPath(pluginPathRoot.localPluginPath)
+
+      if isFrontendArgSupported(.wasmPluginServerPath) {
+        commandLine.appendFlag(.wasmPluginServerPath)
+        commandLine.appendPath(pluginPathRoot.wasmPluginServerPath)
+      }
     }
   }
 
@@ -906,3 +911,15 @@ extension ParsedOptions {
     }
   }
 }
+
+extension VirtualPath {
+  // Given a virtual path pointing into a toolchain/SDK/platform, produce the
+  // path to `swift-wasm-plugin-server`.
+  fileprivate var wasmPluginServerPath: VirtualPath {
+#if os(Windows)
+    self.appending(components: "bin", "swift-wasm-plugin-server.exe")
+#else
+    self.appending(components: "bin", "swift-wasm-plugin-server")
+#endif
+  }
+}

From 0081b2be4dbd31d19e721169ec6d41c9df2e73b6 Mon Sep 17 00:00:00 2001
From: Kabir Oberai <oberai.kabir@gmail.com>
Date: Tue, 16 Apr 2024 15:38:24 -0400
Subject: [PATCH 03/12] hasWasmPlugins

---
 .../SwiftDriver/Jobs/FrontendJobHelpers.swift   | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift b/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
index a21043c1a..7fe669421 100644
--- a/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
+++ b/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
@@ -489,7 +489,9 @@ extension Driver {
       commandLine.appendFlag(.pluginPath)
       commandLine.appendPath(pluginPathRoot.localPluginPath)
 
-      if isFrontendArgSupported(.wasmPluginServerPath) {
+      // Avoid cluttering the invocation with the wasm plugin server path unless
+      // the user has requested to load a wasm macro.
+      if isFrontendArgSupported(.wasmPluginServerPath) && parsedOptions.hasWasmPlugins {
         commandLine.appendFlag(.wasmPluginServerPath)
         commandLine.appendPath(pluginPathRoot.wasmPluginServerPath)
       }
@@ -910,6 +912,19 @@ extension ParsedOptions {
       return experimentalFeatures.map(\.argument).map(\.asSingle).contains("Embedded")
     }
   }
+
+  /// Checks whether there are any `-load-plugin-executable` arguments for WebAssembly plugins.
+  var hasWasmPlugins: Bool {
+    mutating get {
+      let loadPluginExecutables = self.arguments(for: .loadPluginExecutable)
+      return loadPluginExecutables.contains { option in
+        let argument = option.argument.asSingle
+        // the format is <file.ext>#<modules>
+        guard let separator = argument.lastIndex(of: "#") else { return false }
+        return argument[..<separator].hasSuffix(".wasm")
+      }
+    }
+  }
 }
 
 extension VirtualPath {

From 018b4c261f1375d2724cda156eb897b617d14a0c Mon Sep 17 00:00:00 2001
From: Kabir Oberai <oberai.kabir@gmail.com>
Date: Tue, 16 Apr 2024 16:24:22 -0400
Subject: [PATCH 04/12] Add test for wasm plugins

---
 Tests/SwiftDriverTests/SwiftDriverTests.swift | 42 ++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/Tests/SwiftDriverTests/SwiftDriverTests.swift b/Tests/SwiftDriverTests/SwiftDriverTests.swift
index fc63d9ca4..6f46af15a 100644
--- a/Tests/SwiftDriverTests/SwiftDriverTests.swift
+++ b/Tests/SwiftDriverTests/SwiftDriverTests.swift
@@ -7335,7 +7335,7 @@ final class SwiftDriverTests: XCTestCase {
   func pluginPathTest(platform: String, sdk: String, searchPlatform: String) throws {
     let sdkRoot = try testInputsPath.appending(
       components: ["Platform Checks", "\(platform).platform", "Developer", "SDKs", "\(sdk).sdk"])
-    var driver = try Driver(args: ["swiftc", "-typecheck", "foo.swift", "-sdk", VirtualPath.absolute(sdkRoot).name, "-plugin-path", "PluginA", "-external-plugin-path", "Plugin~B#Bexe", "-load-plugin-library", "PluginB2", "-plugin-path", "PluginC", "-working-directory", "/tmp"])
+    var driver = try Driver(args: ["swiftc", "-typecheck", "foo.swift", "-sdk", VirtualPath.absolute(sdkRoot).name, "-plugin-path", "PluginA", "-external-plugin-path", "Plugin~B#Bexe", "-load-plugin-library", "PluginB2", "-plugin-path", "PluginC", "-load-plugin-executable", "PluginD#PluginD", "-working-directory", "/tmp"])
     guard driver.isFrontendArgSupported(.pluginPath) && driver.isFrontendArgSupported(.externalPluginPath) else {
       return
     }
@@ -7383,6 +7383,7 @@ final class SwiftDriverTests: XCTestCase {
     #endif
 
     XCTAssertTrue(job.commandLine.contains(.flag("-plugin-path")))
+    XCTAssertFalse(job.commandLine.contains(.flag("-wasm-plugin-server-path")))
 #if os(Windows)
     XCTAssertTrue(job.commandLine.contains(.path(.absolute(try driver.toolchain.executableDir.parentDirectory.appending(components: "bin")))))
 #else
@@ -7391,6 +7392,45 @@ final class SwiftDriverTests: XCTestCase {
 #endif
   }
 
+  func testWasmPlugins() throws {
+    let sdkRoot = try testInputsPath.appending(
+      components: ["Platform Checks", "iPhoneOS.platform", "Developer", "SDKs", "iPhoneOS13.0.sdk"])
+    let executor = try SwiftDriverExecutor(
+      diagnosticsEngine: DiagnosticsEngine(handlers: [Driver.stderrDiagnosticsHandler]),
+      processSet: ProcessSet(),
+      fileSystem: localFileSystem,
+      env: [:]
+    )
+    let executableDir = try AbsolutePath(validating: "/tmp/swift/bin")
+    var driver = try Driver(
+      args: ["swiftc", "-typecheck", "foo.swift", "-sdk", VirtualPath.absolute(sdkRoot).name, "-load-plugin-executable", "PluginA.wasm#ModuleA", "-working-directory", "/tmp"],
+      executor: executor,
+      compilerExecutableDir: executableDir
+    )
+    guard driver.isFrontendArgSupported(.wasmPluginServerPath) else {
+      return
+    }
+
+    let jobs = try driver.planBuild().removingAutolinkExtractJobs()
+    XCTAssertEqual(jobs.count, 1)
+    let job = jobs.first!
+
+    // Check that the we have the plugin path
+    let pluginAIndex = job.commandLine.firstIndex(of: .path(VirtualPath.absolute(try .init(validating: "/tmp/PluginA.wasm#ModuleA"))))
+    print(job.commandLine)
+    XCTAssertNotNil(pluginAIndex)
+
+    // Check that we also have the wasm plugin server path
+    let wasmPathOptionIndex = try XCTUnwrap(job.commandLine.firstIndex(of: "-wasm-plugin-server-path"))
+    let wasmPath = job.commandLine[wasmPathOptionIndex + 1]
+    #if os(Windows)
+    let expectedWasmServerPath = executableDir.appending(component: "swift-wasm-plugin-server.exe")
+    #else
+    let expectedWasmServerPath = executableDir.appending(component: "swift-wasm-plugin-server")
+    #endif
+    XCTAssertEqual(wasmPath, .path(.absolute(expectedWasmServerPath)))
+  }
+
   func testClangModuleValidateOnce() throws {
     let flagTest = try Driver(args: ["swiftc", "-typecheck", "foo.swift"])
     guard flagTest.isFrontendArgSupported(.clangBuildSessionFile),

From fb902b124ee4043ede67016e662c8887e7ed2c22 Mon Sep 17 00:00:00 2001
From: Kabir Oberai <oberai.kabir@gmail.com>
Date: Tue, 16 Apr 2024 16:26:20 -0400
Subject: [PATCH 05/12] tweaks

---
 Tests/SwiftDriverTests/SwiftDriverTests.swift | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Tests/SwiftDriverTests/SwiftDriverTests.swift b/Tests/SwiftDriverTests/SwiftDriverTests.swift
index 6f46af15a..03cf06a68 100644
--- a/Tests/SwiftDriverTests/SwiftDriverTests.swift
+++ b/Tests/SwiftDriverTests/SwiftDriverTests.swift
@@ -7417,11 +7417,10 @@ final class SwiftDriverTests: XCTestCase {
 
     // Check that the we have the plugin path
     let pluginAIndex = job.commandLine.firstIndex(of: .path(VirtualPath.absolute(try .init(validating: "/tmp/PluginA.wasm#ModuleA"))))
-    print(job.commandLine)
     XCTAssertNotNil(pluginAIndex)
 
     // Check that we also have the wasm plugin server path
-    let wasmPathOptionIndex = try XCTUnwrap(job.commandLine.firstIndex(of: "-wasm-plugin-server-path"))
+    let wasmPathOptionIndex = try XCTUnwrap(job.commandLine.firstIndex(of: .flag("-wasm-plugin-server-path")))
     let wasmPath = job.commandLine[wasmPathOptionIndex + 1]
     #if os(Windows)
     let expectedWasmServerPath = executableDir.appending(component: "swift-wasm-plugin-server.exe")

From a6db182953102c28f6989e6bd92dd668935fb500 Mon Sep 17 00:00:00 2001
From: Kabir Oberai <oberai.kabir@gmail.com>
Date: Sat, 25 May 2024 19:22:22 -0400
Subject: [PATCH 06/12] swift-wasm-plugin-server => swift-plugin-server

---
 Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift  | 14 +-------------
 .../SwiftDriver/Toolchains/DarwinToolchain.swift   |  2 +-
 Tests/SwiftDriverTests/SwiftDriverTests.swift      |  4 ++--
 3 files changed, 4 insertions(+), 16 deletions(-)

diff --git a/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift b/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
index c6731ddb5..4e5be1a56 100644
--- a/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
+++ b/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
@@ -795,7 +795,7 @@ extension Driver {
     // the user has requested to load a wasm macro.
     if isFrontendArgSupported(.wasmPluginServerPath) && parsedOptions.hasWasmPlugins {
       commandLine.appendFlag(.wasmPluginServerPath)
-      commandLine.appendPath(pluginPathRoot.wasmPluginServerPath)
+      commandLine.appendPath(pluginPathRoot.pluginServerPath)
     }
   }
 
@@ -945,15 +945,3 @@ extension ParsedOptions {
     }
   }
 }
-
-extension VirtualPath {
-  // Given a virtual path pointing into a toolchain/SDK/platform, produce the
-  // path to `swift-wasm-plugin-server`.
-  fileprivate var wasmPluginServerPath: VirtualPath {
-#if os(Windows)
-    self.appending(components: "bin", "swift-wasm-plugin-server.exe")
-#else
-    self.appending(components: "bin", "swift-wasm-plugin-server")
-#endif
-  }
-}
diff --git a/Sources/SwiftDriver/Toolchains/DarwinToolchain.swift b/Sources/SwiftDriver/Toolchains/DarwinToolchain.swift
index 303d68bb6..05cb65038 100644
--- a/Sources/SwiftDriver/Toolchains/DarwinToolchain.swift
+++ b/Sources/SwiftDriver/Toolchains/DarwinToolchain.swift
@@ -484,7 +484,7 @@ private extension Version {
 extension VirtualPath {
   // Given a virtual path pointing into a toolchain/SDK/platform, produce the
   // path to `swift-plugin-server`.
-  fileprivate var pluginServerPath: VirtualPath {
+  var pluginServerPath: VirtualPath {
 #if os(Windows)
     self.appending(components: "bin", "swift-plugin-server.exe")
 #else
diff --git a/Tests/SwiftDriverTests/SwiftDriverTests.swift b/Tests/SwiftDriverTests/SwiftDriverTests.swift
index 7b38a620b..fa3015ef4 100644
--- a/Tests/SwiftDriverTests/SwiftDriverTests.swift
+++ b/Tests/SwiftDriverTests/SwiftDriverTests.swift
@@ -7494,9 +7494,9 @@ final class SwiftDriverTests: XCTestCase {
     let wasmPathOptionIndex = try XCTUnwrap(job.commandLine.firstIndex(of: .flag("-wasm-plugin-server-path")))
     let wasmPath = job.commandLine[wasmPathOptionIndex + 1]
     #if os(Windows)
-    let expectedWasmServerPath = executableDir.appending(component: "swift-wasm-plugin-server.exe")
+    let expectedWasmServerPath = executableDir.appending(component: "swift-plugin-server.exe")
     #else
-    let expectedWasmServerPath = executableDir.appending(component: "swift-wasm-plugin-server")
+    let expectedWasmServerPath = executableDir.appending(component: "swift-plugin-server")
     #endif
     XCTAssertEqual(wasmPath, .path(.absolute(expectedWasmServerPath)))
   }

From 39f0a6e260fdb120e0ba7f00ecbb0b610daad48e Mon Sep 17 00:00:00 2001
From: Kabir Oberai <oberai.kabir@gmail.com>
Date: Sat, 25 May 2024 22:34:00 -0400
Subject: [PATCH 07/12] Use -load-plugin

---
 .../SwiftDriver/Jobs/FrontendJobHelpers.swift | 52 ++++++++++++-------
 Sources/SwiftOptions/Options.swift            | 12 +++--
 Tests/SwiftDriverTests/SwiftDriverTests.swift | 14 ++---
 3 files changed, 46 insertions(+), 32 deletions(-)

diff --git a/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift b/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
index 4e5be1a56..c6460b4a2 100644
--- a/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
+++ b/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
@@ -309,7 +309,10 @@ extension Driver {
     }
 
     // Emit user-provided plugin paths, in order.
-    if isFrontendArgSupported(.externalPluginPath) {
+    if isFrontendArgSupported(.loadPlugin) {
+      try commandLine.appendAll(.pluginPath, .externalPluginPath, .loadPluginLibrary, .loadPlugin, from: &parsedOptions)
+      try addLoadPluginExecutableArguments(commandLine: &commandLine)
+    } else if isFrontendArgSupported(.externalPluginPath) {
       try commandLine.appendAll(.pluginPath, .externalPluginPath, .loadPluginLibrary, .loadPluginExecutable, from: &parsedOptions)
     } else if isFrontendArgSupported(.pluginPath) {
       try commandLine.appendAll(.pluginPath, .loadPluginLibrary, from: &parsedOptions)
@@ -790,12 +793,36 @@ extension Driver {
 
     commandLine.appendFlag(.pluginPath)
     commandLine.appendPath(pluginPathRoot.localPluginPath)
+  }
+
+  mutating func addLoadPluginExecutableArguments(commandLine: inout [Job.ArgTemplate]) throws {
+    var cachedPluginServerPath: VirtualPath?
+    var pluginServerPath: VirtualPath {
+      get throws {
+        if let cachedPluginServerPath = cachedPluginServerPath {
+          return cachedPluginServerPath
+        }
+        let pluginPathRoot = VirtualPath.absolute(try toolchain.executableDir.parentDirectory)
+        let pluginServerPath = pluginPathRoot.pluginServerPath
+        cachedPluginServerPath = pluginServerPath
+        return pluginServerPath
+      }
+    }
+
+    for loadPluginExecutable in parsedOptions.arguments(for: .loadPluginExecutable) {
+      let argument = loadPluginExecutable.argument.asSingle
+      guard let separator = argument.lastIndex(of: "#") else { continue }
+
+      let path = argument[..<separator]
+      let afterPath = argument[separator...]
 
-    // Avoid cluttering the invocation with the wasm plugin server path unless
-    // the user has requested to load a wasm macro.
-    if isFrontendArgSupported(.wasmPluginServerPath) && parsedOptions.hasWasmPlugins {
-      commandLine.appendFlag(.wasmPluginServerPath)
-      commandLine.appendPath(pluginPathRoot.pluginServerPath)
+      guard path.hasSuffix(".wasm") else {
+        try commandLine.append(loadPluginExecutable)
+        continue
+      }
+
+      commandLine.appendFlag(.loadPlugin)
+      try commandLine.appendFlag("\(path):\(pluginServerPath)\(afterPath)")
     }
   }
 
@@ -931,17 +958,4 @@ extension ParsedOptions {
       return experimentalFeatures.map(\.argument).map(\.asSingle).contains("Embedded")
     }
   }
-
-  /// Checks whether there are any `-load-plugin-executable` arguments for WebAssembly plugins.
-  var hasWasmPlugins: Bool {
-    mutating get {
-      let loadPluginExecutables = self.arguments(for: .loadPluginExecutable)
-      return loadPluginExecutables.contains { option in
-        let argument = option.argument.asSingle
-        // the format is <file.ext>#<modules>
-        guard let separator = argument.lastIndex(of: "#") else { return false }
-        return argument[..<separator].hasSuffix(".wasm")
-      }
-    }
-  }
 }
diff --git a/Sources/SwiftOptions/Options.swift b/Sources/SwiftOptions/Options.swift
index 1f2006744..b7b9a56ac 100644
--- a/Sources/SwiftOptions/Options.swift
+++ b/Sources/SwiftOptions/Options.swift
@@ -164,6 +164,7 @@ extension Option {
   public static let disableColocateTypeDescriptors: Option = Option("-disable-colocate-type-descriptors", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable colocate type descriptors")
   public static let disableConcreteTypeMetadataMangledNameAccessors: Option = Option("-disable-concrete-type-metadata-mangled-name-accessors", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable concrete type metadata access by mangled name")
   public static let disableConstraintSolverPerformanceHacks: Option = Option("-disable-constraint-solver-performance-hacks", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable all the hacks in the constraint solver")
+  public static let disableCrossImportOverlaySearch: Option = Option("-disable-cross-import-overlay-search", .flag, attributes: [.frontend, .noDriver], helpText: "Disable searching for cross import overlay file")
   public static let disableCrossImportOverlays: Option = Option("-disable-cross-import-overlays", .flag, attributes: [.frontend, .noDriver], helpText: "Do not automatically import declared cross-import overlays.")
   public static let cxxInteropDisableRequirementAtImport: Option = Option("-disable-cxx-interop-requirement-at-import", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Do not require C++ interoperability to be enabled when importing a Swift module that enables C++ interoperability")
   public static let disableDebuggerShadowCopies: Option = Option("-disable-debugger-shadow-copies", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable debugger shadow copies of local variables.This option is only useful for testing the compiler.")
@@ -183,6 +184,7 @@ extension Option {
   public static let disableGenericMetadataPrespecialization: Option = Option("-disable-generic-metadata-prespecialization", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Do not statically specialize metadata for generic types at types that are known to be used in source.")
   public static let disableImplicitBacktracingModuleImport: Option = Option("-disable-implicit-backtracing-module-import", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable the implicit import of the _Backtracing module.")
   public static let disableImplicitConcurrencyModuleImport: Option = Option("-disable-implicit-concurrency-module-import", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable the implicit import of the _Concurrency module.")
+  public static let disableImplicitCxxModuleImport: Option = Option("-disable-implicit-cxx-module-import", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable the implicit import of the C++ Standard Library module.")
   public static let disableImplicitStringProcessingModuleImport: Option = Option("-disable-implicit-string-processing-module-import", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable the implicit import of the _StringProcessing module.")
   public static let disableImplicitSwiftModules: Option = Option("-disable-implicit-swift-modules", .flag, attributes: [.frontend, .noDriver], helpText: "Disable building Swift modules implicitly by the compiler")
   public static let disableImportPtrauthFieldFunctionPointers: Option = Option("-disable-import-ptrauth-field-function-pointers", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Disable import of custom ptrauth qualified field function pointers")
@@ -486,7 +488,6 @@ extension Option {
   public static let experimentalPrintFullConvention: Option = Option("-experimental-print-full-convention", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "When emitting a module interface or SIL, emit additional @convention arguments, regardless of whether they were written in the source. Also requires -use-clang-function-types to be enabled.")
   public static let experimentalSkipAllFunctionBodies: Option = Option("-experimental-skip-all-function-bodies", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Skip type-checking function bodies and all SIL generation")
   public static let experimentalSkipNonExportableDecls: Option = Option("-experimental-skip-non-exportable-decls", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Skip decls that are not exported to clients")
-  public static let experimentalSkipNonInlinableFunctionBodiesIsLazy: Option = Option("-experimental-skip-non-inlinable-function-bodies-is-lazy", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Infer lazy typechecking for -experimental-skip-non-inlinable-function-bodies")
   public static let experimentalSkipNonInlinableFunctionBodiesWithoutTypes: Option = Option("-experimental-skip-non-inlinable-function-bodies-without-types", .flag, attributes: [.helpHidden, .frontend], helpText: "Skip work on non-inlinable function bodies that do not declare nested types")
   public static let experimentalSkipNonInlinableFunctionBodies: Option = Option("-experimental-skip-non-inlinable-function-bodies", .flag, attributes: [.helpHidden, .frontend], helpText: "Skip type-checking and SIL generation for non-inlinable function bodies")
   public static let experimentalSpiImports: Option = Option("-experimental-spi-imports", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Enable experimental support for SPI imports")
@@ -584,6 +585,7 @@ extension Option {
   public static let reuseDependencyScanCache: Option = Option("-load-dependency-scan-cache", .flag, attributes: [.frontend, .noDriver], helpText: "After performing a dependency scan, serialize the scanner's internal state.")
   public static let loadPluginExecutable: Option = Option("-load-plugin-executable", .separate, attributes: [.frontend, .doesNotAffectIncrementalBuild, .argumentIsPath], metaVar: "<path>#<module-names>", helpText: "Path to a compiler plugin executable and a comma-separated list of module names where the macro types are declared", group: .pluginSearch)
   public static let loadPluginLibrary: Option = Option("-load-plugin-library", .separate, attributes: [.frontend, .doesNotAffectIncrementalBuild, .argumentIsPath], metaVar: "<path>", helpText: "Path to a dynamic library containing compiler plugins such as macros", group: .pluginSearch)
+  public static let loadPlugin: Option = Option("-load-plugin", .separate, attributes: [.frontend, .doesNotAffectIncrementalBuild], metaVar: "<library-path>:<server-path>#<module-names>", helpText: "Path to a plugin library, a server to load it in, and a comma-separated list of module names where the macro types are declared", group: .pluginSearch)
   public static let locale: Option = Option("-locale", .separate, attributes: [.frontend, .doesNotAffectIncrementalBuild], metaVar: "<locale-code>", helpText: "Choose a language for diagnostic messages")
   public static let localizationPath: Option = Option("-localization-path", .separate, attributes: [.frontend, .doesNotAffectIncrementalBuild, .argumentIsPath], metaVar: "<path>", helpText: "Path to localized diagnostic messages directory")
   public static let location: Option = Option("-location", .separate, attributes: [.noDriver], metaVar: "<location>", helpText: "Filter nodes with the given location.")
@@ -775,6 +777,7 @@ extension Option {
   public static let suppressStaticExclusivitySwap: Option = Option("-suppress-static-exclusivity-swap", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Suppress static violations of exclusive access with swap()")
   public static let suppressWarnings: Option = Option("-suppress-warnings", .flag, attributes: [.frontend], helpText: "Suppress all warnings")
   public static let swiftAsyncFramePointerEQ: Option = Option("-swift-async-frame-pointer=", .joined, attributes: [.helpHidden, .frontend, .noDriver], helpText: "One of 'auto', 'always' or 'never'")
+  public static let swiftModuleCrossImport: Option = Option("-swift-module-cross-import", .multiArg, attributes: [.frontend, .noDriver], metaVar: "<moduleName> <crossImport.swiftoverlay>", helpText: "Specify the cross import module", numArgs: 2)
   public static let swiftModuleFile: Option = Option("-swift-module-file=", .joined, attributes: [.frontend, .noDriver], metaVar: "<name>=<path>", helpText: "Specify Swift module input explicitly built from textual interface")
   public static let swiftOnly: Option = Option("-swift-only", .flag, attributes: [.noDriver], helpText: "Only include APIs defined from Swift source")
   public static let swiftOnly_: Option = Option("--swift-only", .flag, alias: Option.swiftOnly, attributes: [.noDriver], helpText: "Only include APIs defined from Swift source")
@@ -856,7 +859,6 @@ extension Option {
   public static let warnSwift3ObjcInferenceMinimal: Option = Option("-warn-swift3-objc-inference-minimal", .flag, attributes: [.helpHidden, .frontend, .doesNotAffectIncrementalBuild], helpText: "Deprecated, has no effect")
   public static let warnSwift3ObjcInference: Option = Option("-warn-swift3-objc-inference", .flag, alias: Option.warnSwift3ObjcInferenceComplete, attributes: [.helpHidden, .frontend, .doesNotAffectIncrementalBuild])
   public static let warningsAsErrors: Option = Option("-warnings-as-errors", .flag, attributes: [.frontend], helpText: "Treat warnings as errors")
-  public static let wasmPluginServerPath: Option = Option("-wasm-plugin-server-path", .separate, attributes: [.frontend, .noDriver], metaVar: "<path>", helpText: "Path to the swift-wasm-plugin-server executable")
   public static let weakLinkAtTarget: Option = Option("-weak-link-at-target", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Weakly link symbols for declarations that were introduced at the deployment target. Symbols introduced before the deployment target are still strongly linked.")
   public static let wholeModuleOptimization: Option = Option("-whole-module-optimization", .flag, attributes: [.frontend, .noInteractive], helpText: "Optimize input files together instead of individually")
   public static let windowsSdkRoot: Option = Option("-windows-sdk-root", .separate, attributes: [.frontend, .argumentIsPath], metaVar: "<root>", helpText: "Windows SDK Root")
@@ -1021,6 +1023,7 @@ extension Option {
       Option.disableColocateTypeDescriptors,
       Option.disableConcreteTypeMetadataMangledNameAccessors,
       Option.disableConstraintSolverPerformanceHacks,
+      Option.disableCrossImportOverlaySearch,
       Option.disableCrossImportOverlays,
       Option.cxxInteropDisableRequirementAtImport,
       Option.disableDebuggerShadowCopies,
@@ -1040,6 +1043,7 @@ extension Option {
       Option.disableGenericMetadataPrespecialization,
       Option.disableImplicitBacktracingModuleImport,
       Option.disableImplicitConcurrencyModuleImport,
+      Option.disableImplicitCxxModuleImport,
       Option.disableImplicitStringProcessingModuleImport,
       Option.disableImplicitSwiftModules,
       Option.disableImportPtrauthFieldFunctionPointers,
@@ -1343,7 +1347,6 @@ extension Option {
       Option.experimentalPrintFullConvention,
       Option.experimentalSkipAllFunctionBodies,
       Option.experimentalSkipNonExportableDecls,
-      Option.experimentalSkipNonInlinableFunctionBodiesIsLazy,
       Option.experimentalSkipNonInlinableFunctionBodiesWithoutTypes,
       Option.experimentalSkipNonInlinableFunctionBodies,
       Option.experimentalSpiImports,
@@ -1441,6 +1444,7 @@ extension Option {
       Option.reuseDependencyScanCache,
       Option.loadPluginExecutable,
       Option.loadPluginLibrary,
+      Option.loadPlugin,
       Option.locale,
       Option.localizationPath,
       Option.location,
@@ -1632,6 +1636,7 @@ extension Option {
       Option.suppressStaticExclusivitySwap,
       Option.suppressWarnings,
       Option.swiftAsyncFramePointerEQ,
+      Option.swiftModuleCrossImport,
       Option.swiftModuleFile,
       Option.swiftOnly,
       Option.swiftOnly_,
@@ -1713,7 +1718,6 @@ extension Option {
       Option.warnSwift3ObjcInferenceMinimal,
       Option.warnSwift3ObjcInference,
       Option.warningsAsErrors,
-      Option.wasmPluginServerPath,
       Option.weakLinkAtTarget,
       Option.wholeModuleOptimization,
       Option.windowsSdkRoot,
diff --git a/Tests/SwiftDriverTests/SwiftDriverTests.swift b/Tests/SwiftDriverTests/SwiftDriverTests.swift
index fa3015ef4..e4c2e444e 100644
--- a/Tests/SwiftDriverTests/SwiftDriverTests.swift
+++ b/Tests/SwiftDriverTests/SwiftDriverTests.swift
@@ -7478,7 +7478,7 @@ final class SwiftDriverTests: XCTestCase {
       executor: executor,
       compilerExecutableDir: executableDir
     )
-    guard driver.isFrontendArgSupported(.wasmPluginServerPath) else {
+    guard driver.isFrontendArgSupported(.loadPlugin) else {
       return
     }
 
@@ -7486,19 +7486,15 @@ final class SwiftDriverTests: XCTestCase {
     XCTAssertEqual(jobs.count, 1)
     let job = jobs.first!
 
-    // Check that the we have the plugin path
-    let pluginAIndex = job.commandLine.firstIndex(of: .path(VirtualPath.absolute(try .init(validating: "/tmp/PluginA.wasm#ModuleA"))))
-    XCTAssertNotNil(pluginAIndex)
-
-    // Check that we also have the wasm plugin server path
-    let wasmPathOptionIndex = try XCTUnwrap(job.commandLine.firstIndex(of: .flag("-wasm-plugin-server-path")))
-    let wasmPath = job.commandLine[wasmPathOptionIndex + 1]
     #if os(Windows)
     let expectedWasmServerPath = executableDir.appending(component: "swift-plugin-server.exe")
     #else
     let expectedWasmServerPath = executableDir.appending(component: "swift-plugin-server")
     #endif
-    XCTAssertEqual(wasmPath, .path(.absolute(expectedWasmServerPath)))
+
+    // Check that the we have the plugin path
+    let pluginAIndex = job.commandLine.firstIndex(of: .flag("/tmp/PluginA.wasm:\(expectedWasmServerPath)#ModuleA"))
+    XCTAssertNotNil(pluginAIndex)
   }
 
   func testClangModuleValidateOnce() throws {

From 1eb80db3d277d370dac5849591a6d7b9ca3a9fe7 Mon Sep 17 00:00:00 2001
From: Kabir Oberai <oberai.kabir@gmail.com>
Date: Sat, 25 May 2024 22:36:22 -0400
Subject: [PATCH 08/12] Move pluginServerPath extension

---
 Sources/SwiftDriver/Toolchains/DarwinToolchain.swift | 10 ----------
 Sources/SwiftDriver/Toolchains/Toolchain.swift       | 12 ++++++++++++
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/Sources/SwiftDriver/Toolchains/DarwinToolchain.swift b/Sources/SwiftDriver/Toolchains/DarwinToolchain.swift
index 05cb65038..7cf4ca4e8 100644
--- a/Sources/SwiftDriver/Toolchains/DarwinToolchain.swift
+++ b/Sources/SwiftDriver/Toolchains/DarwinToolchain.swift
@@ -482,16 +482,6 @@ private extension Version {
 }
 
 extension VirtualPath {
-  // Given a virtual path pointing into a toolchain/SDK/platform, produce the
-  // path to `swift-plugin-server`.
-  var pluginServerPath: VirtualPath {
-#if os(Windows)
-    self.appending(components: "bin", "swift-plugin-server.exe")
-#else
-    self.appending(components: "bin", "swift-plugin-server")
-#endif
-  }
-
   // Given a virtual path pointing into a toolchain/SDK/platform, produce the
   // path to the plugins.
   var pluginPath: VirtualPath {
diff --git a/Sources/SwiftDriver/Toolchains/Toolchain.swift b/Sources/SwiftDriver/Toolchains/Toolchain.swift
index 214ff8597..3c3c685de 100644
--- a/Sources/SwiftDriver/Toolchains/Toolchain.swift
+++ b/Sources/SwiftDriver/Toolchains/Toolchain.swift
@@ -371,3 +371,15 @@ extension Toolchain {
 @_spi(Testing) public enum ToolchainError: Swift.Error {
   case unableToFind(tool: String)
 }
+
+extension VirtualPath {
+  // Given a virtual path pointing into a toolchain/SDK/platform, produce the
+  // path to `swift-plugin-server`.
+  var pluginServerPath: VirtualPath {
+#if os(Windows)
+    self.appending(components: "bin", "swift-plugin-server.exe")
+#else
+    self.appending(components: "bin", "swift-plugin-server")
+#endif
+  }
+}

From 3e450cb6395b91c6488d25beb82a3468b0423bfb Mon Sep 17 00:00:00 2001
From: Kabir Oberai <oberai.kabir@gmail.com>
Date: Sat, 25 May 2024 22:40:11 -0400
Subject: [PATCH 09/12] Tweaks

---
 Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift | 3 +++
 Tests/SwiftDriverTests/SwiftDriverTests.swift     | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift b/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
index c6460b4a2..d238427a1 100644
--- a/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
+++ b/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
@@ -795,6 +795,9 @@ extension Driver {
     commandLine.appendPath(pluginPathRoot.localPluginPath)
   }
 
+  /// Forward `-load-plugin-executable` arguments, with special handling for Wasm plugins.
+  ///
+  /// Wasm plugins are updated to use `-load-plugin` with the plugin server.
   mutating func addLoadPluginExecutableArguments(commandLine: inout [Job.ArgTemplate]) throws {
     var cachedPluginServerPath: VirtualPath?
     var pluginServerPath: VirtualPath {
diff --git a/Tests/SwiftDriverTests/SwiftDriverTests.swift b/Tests/SwiftDriverTests/SwiftDriverTests.swift
index e4c2e444e..d744e082d 100644
--- a/Tests/SwiftDriverTests/SwiftDriverTests.swift
+++ b/Tests/SwiftDriverTests/SwiftDriverTests.swift
@@ -7454,7 +7454,7 @@ final class SwiftDriverTests: XCTestCase {
     #endif
 
     XCTAssertTrue(job.commandLine.contains(.flag("-plugin-path")))
-    XCTAssertFalse(job.commandLine.contains(.flag("-wasm-plugin-server-path")))
+    XCTAssertFalse(job.commandLine.contains(.flag("-load-plugin")))
 #if os(Windows)
     XCTAssertTrue(job.commandLine.contains(.path(.absolute(try driver.toolchain.executableDir.parentDirectory.appending(components: "bin")))))
 #else

From dc640ff5160e979eacc24b02e04dcf428f946289 Mon Sep 17 00:00:00 2001
From: Kabir Oberai <oberai.kabir@gmail.com>
Date: Wed, 12 Jun 2024 15:43:51 +0530
Subject: [PATCH 10/12] Preserve order of options

---
 .../SwiftDriver/Jobs/FrontendJobHelpers.swift | 67 +++++++++++--------
 Tests/SwiftDriverTests/SwiftDriverTests.swift | 14 ++--
 2 files changed, 47 insertions(+), 34 deletions(-)

diff --git a/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift b/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
index 639c47ac2..3104d4a6d 100644
--- a/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
+++ b/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
@@ -313,8 +313,8 @@ extension Driver {
 
     // Emit user-provided plugin paths, in order.
     if isFrontendArgSupported(.loadPlugin) {
-      try commandLine.appendAll(.pluginPath, .externalPluginPath, .loadPluginLibrary, .loadPlugin, from: &parsedOptions)
-      try addLoadPluginExecutableArguments(commandLine: &commandLine)
+      let options = parsedOptions.arguments(for: .pluginPath, .externalPluginPath, .loadPluginLibrary, .loadPluginExecutable, .loadPlugin)
+      try commandLine.append(contentsOf: transformPluginOptions(options))
     } else if isFrontendArgSupported(.externalPluginPath) {
       try commandLine.appendAll(.pluginPath, .externalPluginPath, .loadPluginLibrary, .loadPluginExecutable, from: &parsedOptions)
     } else if isFrontendArgSupported(.pluginPath) {
@@ -804,40 +804,51 @@ extension Driver {
     commandLine.appendPath(pluginPathRoot.localPluginPath)
   }
 
-  /// Forward `-load-plugin-executable` arguments, with special handling for Wasm plugins.
+  /// Forward all plugin-related arguments, with special handling for Wasm plugins requested via `-load-plugin-executable`.
   ///
   /// Wasm plugins are updated to use `-load-plugin` with the plugin server.
-  mutating func addLoadPluginExecutableArguments(commandLine: inout [Job.ArgTemplate]) throws {
-    var cachedPluginServerPath: VirtualPath?
-    var pluginServerPath: VirtualPath {
-      get throws {
-        if let cachedPluginServerPath = cachedPluginServerPath {
-          return cachedPluginServerPath
-        }
-        let pluginPathRoot = VirtualPath.absolute(try toolchain.executableDir.parentDirectory)
-        let pluginServerPath = pluginPathRoot.pluginServerPath
-        cachedPluginServerPath = pluginServerPath
-        return pluginServerPath
-      }
+  private func transformPluginOptions(_ options: [ParsedOption]) throws -> [ParsedOption] {
+    lazy var pluginServerPathResult = Result {
+      VirtualPath.absolute(try toolchain.executableDir.parentDirectory).pluginServerPath
+    }
+    return try options.map { pluginOption in
+      try transformPluginOption(
+        pluginOption,
+        // Not the same as `pluginServerPath: pluginServerPathResult.get`.
+        // We want to ensure that `pluginServerPathResult` is lazily initialized.
+        pluginServerPath: { try pluginServerPathResult.get() }
+      )
+    }
+  }
+
+  /// Transforms a single plugin-related option to handle Wasm plugins.
+  ///
+  /// If the option is of the form `-load-plugin-executable foo.wasm`, it's updated to use
+  /// `-load-plugin` with the plugin server. Otherwise, it's returned unmodified.
+  private func transformPluginOption(
+    _ pluginOption: ParsedOption,
+    pluginServerPath: () throws -> VirtualPath
+  ) throws -> ParsedOption {
+    guard pluginOption.option == .loadPluginExecutable else {
+      return pluginOption
     }
 
-    for loadPluginExecutable in parsedOptions.arguments(for: .loadPluginExecutable) {
-      let argument = loadPluginExecutable.argument.asSingle
-      guard let separator = argument.lastIndex(of: "#") else { continue }
+    let argument = pluginOption.argument.asSingle
+    guard let separator = argument.lastIndex(of: "#") else { return pluginOption }
 
-      let path = argument[..<separator]
-      let afterPath = argument[separator...]
+    let path = argument[..<separator]
+    let afterPath = argument[separator...]
 
-      guard path.hasSuffix(".wasm") else {
-        try commandLine.append(loadPluginExecutable)
-        continue
-      }
+    guard path.hasSuffix(".wasm") else { return pluginOption }
 
-      commandLine.appendFlag(.loadPlugin)
-      try commandLine.appendFlag("\(path):\(pluginServerPath)\(afterPath)")
-    }
-  }
+    let pluginServerPath = try pluginServerPath()
 
+    return ParsedOption(
+      option: .loadPlugin,
+      argument: .single("\(path):\(pluginServerPath)\(afterPath)"), 
+      index: pluginOption.index
+    )
+  }
 
   /// If explicit dependency planner supports creating bridging header pch command.
   public func supportsBridgingHeaderPCHCommand() throws -> Bool {
diff --git a/Tests/SwiftDriverTests/SwiftDriverTests.swift b/Tests/SwiftDriverTests/SwiftDriverTests.swift
index c7b350a29..c76c2eed5 100644
--- a/Tests/SwiftDriverTests/SwiftDriverTests.swift
+++ b/Tests/SwiftDriverTests/SwiftDriverTests.swift
@@ -7497,13 +7497,11 @@ final class SwiftDriverTests: XCTestCase {
     )
     let executableDir = try AbsolutePath(validating: "/tmp/swift/bin")
     var driver = try Driver(
-      args: ["swiftc", "-typecheck", "foo.swift", "-sdk", VirtualPath.absolute(sdkRoot).name, "-load-plugin-executable", "PluginA.wasm#ModuleA", "-working-directory", "/tmp"],
+      args: ["swiftc", "-typecheck", "foo.swift", "-sdk", VirtualPath.absolute(sdkRoot).name, "-load-plugin-executable", "PluginA#ModuleA", "-load-plugin-executable", "PluginB.wasm#ModuleB", "-working-directory", "/tmp", "-load-plugin-library", "PluginC.dylib"],
       executor: executor,
       compilerExecutableDir: executableDir
     )
-    guard driver.isFrontendArgSupported(.loadPlugin) else {
-      return
-    }
+    try XCTSkipUnless(driver.isFrontendArgSupported(.loadPlugin))
 
     let jobs = try driver.planBuild().removingAutolinkExtractJobs()
     XCTAssertEqual(jobs.count, 1)
@@ -7516,8 +7514,12 @@ final class SwiftDriverTests: XCTestCase {
     #endif
 
     // Check that the we have the plugin path
-    let pluginAIndex = job.commandLine.firstIndex(of: .flag("/tmp/PluginA.wasm:\(expectedWasmServerPath)#ModuleA"))
-    XCTAssertNotNil(pluginAIndex)
+    let pluginAIndex = try XCTUnwrap(job.commandLine.firstIndex(of: .path(.absolute(AbsolutePath(validating: "/tmp/PluginA#ModuleA")))))
+    let pluginBIndex = try XCTUnwrap(job.commandLine.firstIndex(of: .flag("/tmp/PluginB.wasm:\(expectedWasmServerPath)#ModuleB")))
+    let pluginCIndex = try XCTUnwrap(job.commandLine.firstIndex(of: .path(.absolute(AbsolutePath(validating: "/tmp/PluginC.dylib")))))
+
+    XCTAssertLessThan(pluginAIndex, pluginBIndex, "Order of options should be preserved")
+    XCTAssertLessThan(pluginBIndex, pluginCIndex, "Order of options should be preserved")
   }
 
   func testClangModuleValidateOnce() throws {

From 74e989c90bb42b4973aa51dc431807df7aefa9f1 Mon Sep 17 00:00:00 2001
From: Kabir Oberai <oberai.kabir@gmail.com>
Date: Wed, 12 Jun 2024 15:46:42 +0530
Subject: [PATCH 11/12] formatting

---
 Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift b/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
index 3104d4a6d..fcff5d269 100644
--- a/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
+++ b/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
@@ -834,13 +834,16 @@ extension Driver {
     }
 
     let argument = pluginOption.argument.asSingle
-    guard let separator = argument.lastIndex(of: "#") else { return pluginOption }
+    guard let separator = argument.lastIndex(of: "#") else {
+      return pluginOption
+    }
 
     let path = argument[..<separator]
+    guard path.hasSuffix(".wasm") else {
+      return pluginOption
+    }
     let afterPath = argument[separator...]
 
-    guard path.hasSuffix(".wasm") else { return pluginOption }
-
     let pluginServerPath = try pluginServerPath()
 
     return ParsedOption(

From 80ca24d9142fef69c24ca05df38947ab5d2a7587 Mon Sep 17 00:00:00 2001
From: Kabir Oberai <oberai.kabir@gmail.com>
Date: Wed, 12 Jun 2024 16:00:15 +0530
Subject: [PATCH 12/12] Minor renaming

---
 .../SwiftDriver/Jobs/FrontendJobHelpers.swift | 74 +++++++++----------
 1 file changed, 37 insertions(+), 37 deletions(-)

diff --git a/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift b/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
index fcff5d269..dcb6c57d0 100644
--- a/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
+++ b/Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift
@@ -314,7 +314,7 @@ extension Driver {
     // Emit user-provided plugin paths, in order.
     if isFrontendArgSupported(.loadPlugin) {
       let options = parsedOptions.arguments(for: .pluginPath, .externalPluginPath, .loadPluginLibrary, .loadPluginExecutable, .loadPlugin)
-      try commandLine.append(contentsOf: transformPluginOptions(options))
+      try commandLine.append(contentsOf: handleWasmPlugins(options))
     } else if isFrontendArgSupported(.externalPluginPath) {
       try commandLine.appendAll(.pluginPath, .externalPluginPath, .loadPluginLibrary, .loadPluginExecutable, from: &parsedOptions)
     } else if isFrontendArgSupported(.pluginPath) {
@@ -807,13 +807,12 @@ extension Driver {
   /// Forward all plugin-related arguments, with special handling for Wasm plugins requested via `-load-plugin-executable`.
   ///
   /// Wasm plugins are updated to use `-load-plugin` with the plugin server.
-  private func transformPluginOptions(_ options: [ParsedOption]) throws -> [ParsedOption] {
+  private func handleWasmPlugins(_ options: [ParsedOption]) throws -> [ParsedOption] {
     lazy var pluginServerPathResult = Result {
       VirtualPath.absolute(try toolchain.executableDir.parentDirectory).pluginServerPath
     }
-    return try options.map { pluginOption in
-      try transformPluginOption(
-        pluginOption,
+    return try options.map { option in
+      try option.handlingWasmPlugins(
         // Not the same as `pluginServerPath: pluginServerPathResult.get`.
         // We want to ensure that `pluginServerPathResult` is lazily initialized.
         pluginServerPath: { try pluginServerPathResult.get() }
@@ -821,38 +820,6 @@ extension Driver {
     }
   }
 
-  /// Transforms a single plugin-related option to handle Wasm plugins.
-  ///
-  /// If the option is of the form `-load-plugin-executable foo.wasm`, it's updated to use
-  /// `-load-plugin` with the plugin server. Otherwise, it's returned unmodified.
-  private func transformPluginOption(
-    _ pluginOption: ParsedOption,
-    pluginServerPath: () throws -> VirtualPath
-  ) throws -> ParsedOption {
-    guard pluginOption.option == .loadPluginExecutable else {
-      return pluginOption
-    }
-
-    let argument = pluginOption.argument.asSingle
-    guard let separator = argument.lastIndex(of: "#") else {
-      return pluginOption
-    }
-
-    let path = argument[..<separator]
-    guard path.hasSuffix(".wasm") else {
-      return pluginOption
-    }
-    let afterPath = argument[separator...]
-
-    let pluginServerPath = try pluginServerPath()
-
-    return ParsedOption(
-      option: .loadPlugin,
-      argument: .single("\(path):\(pluginServerPath)\(afterPath)"), 
-      index: pluginOption.index
-    )
-  }
-
   /// If explicit dependency planner supports creating bridging header pch command.
   public func supportsBridgingHeaderPCHCommand() throws -> Bool {
     return try explicitDependencyBuildPlanner?.supportsBridgingHeaderPCHCommand() ?? false
@@ -985,3 +952,36 @@ extension ParsedOptions {
     }
   }
 }
+
+extension ParsedOption {
+  /// Transforms the receiver to handle Wasm plugins.
+  ///
+  /// If the option is of the form `-load-plugin-executable foo.wasm`, it's updated to use
+  /// `-load-plugin` with the plugin server. Otherwise, it's returned unmodified.
+  fileprivate func handlingWasmPlugins(
+    pluginServerPath: () throws -> VirtualPath
+  ) throws -> ParsedOption {
+    guard option == .loadPluginExecutable else {
+      return self
+    }
+
+    let argument = argument.asSingle
+    guard let separator = argument.lastIndex(of: "#") else {
+      return self
+    }
+
+    let path = argument[..<separator]
+    guard path.hasSuffix(".wasm") else {
+      return self
+    }
+    let afterPath = argument[separator...]
+
+    let pluginServerPath = try pluginServerPath()
+
+    return ParsedOption(
+      option: .loadPlugin,
+      argument: .single("\(path):\(pluginServerPath)\(afterPath)"),
+      index: index
+    )
+  }
+}