Fix wrong -Xlinker propagation to Clang with WebAssembly

Sources/SwiftDriver/Jobs/DarwinToolchain+LinkerSupport.swift

@@ -272,13 +272,7 @@ extension DarwinToolchain {
       from: &parsedOptions
     )
     addLinkedLibArgs(to: &commandLine, parsedOptions: &parsedOptions)
-    // Because we invoke `clang` as the linker executable, we must still
-    // use `-Xlinker` for linker-specific arguments.
-    for linkerOpt in parsedOptions.arguments(for: .Xlinker) {
-      commandLine.appendFlag(.Xlinker)
-      commandLine.appendFlag(linkerOpt.argument.asSingle)
-    }
-    try commandLine.appendAllArguments(.XclangLinker, from: &parsedOptions)
+    try addExtraClangLinkerArgs(to: &commandLine, parsedOptions: &parsedOptions)
   }
 }
 

Sources/SwiftDriver/Jobs/GenericUnixToolchain+LinkerSupport.swift

@@ -321,13 +321,7 @@ extension GenericUnixToolchain {
         from: &parsedOptions
       )
       addLinkedLibArgs(to: &commandLine, parsedOptions: &parsedOptions)
-      // Because we invoke `clang` as the linker executable, we must still
-      // use `-Xlinker` for linker-specific arguments.
-      for linkerOpt in parsedOptions.arguments(for: .Xlinker) {
-        commandLine.appendFlag(.Xlinker)
-        commandLine.appendFlag(linkerOpt.argument.asSingle)
-      }
-      try commandLine.appendAllArguments(.XclangLinker, from: &parsedOptions)
+      try addExtraClangLinkerArgs(to: &commandLine, parsedOptions: &parsedOptions)
 
       // This should be the last option, for convenience in checking output.
       commandLine.appendFlag(.o)

Sources/SwiftDriver/Jobs/Toolchain+LinkerSupport.swift

@@ -90,6 +90,19 @@ extension Toolchain {
       commandLine.appendFlag(match.option.spelling + match.argument.asSingle)
     }
   }
+
+  func addExtraClangLinkerArgs(
+    to commandLine: inout [Job.ArgTemplate],
+    parsedOptions: inout ParsedOptions
+  ) throws {
+    // Because we invoke `clang` as the linker executable, we must still
+    // use `-Xlinker` for linker-specific arguments.
+    for linkerOpt in parsedOptions.arguments(for: .Xlinker) {
+      commandLine.appendFlag(.Xlinker)
+      commandLine.appendFlag(linkerOpt.argument.asSingle)
+    }
+    try commandLine.appendAllArguments(.XclangLinker, from: &parsedOptions)
+  }
 }
 
 // MARK: - Common argument routines

Sources/SwiftDriver/Jobs/WebAssemblyToolchain+LinkerSupport.swift

@@ -158,8 +158,7 @@ extension WebAssemblyToolchain {
         from: &parsedOptions
       )
       addLinkedLibArgs(to: &commandLine, parsedOptions: &parsedOptions)
-      try commandLine.appendAllArguments(.Xlinker, from: &parsedOptions)
-      try commandLine.appendAllArguments(.XclangLinker, from: &parsedOptions)
+      try addExtraClangLinkerArgs(to: &commandLine, parsedOptions: &parsedOptions)
 
         // This should be the last option, for convenience in checking output.
       commandLine.appendFlag(.o)

Sources/SwiftDriver/Jobs/WindowsToolchain+LinkerSupport.swift

@@ -197,12 +197,7 @@ extension WindowsToolchain {
       commandLine.appendFlag("-lclang_rt.profile")
     }
 
-    for option in parsedOptions.arguments(for: .Xlinker) {
-      commandLine.appendFlag(.Xlinker)
-      commandLine.appendFlag(option.argument.asSingle)
-    }
-    // TODO(compnerd) is there a separate equivalent to OPT_linker_option_group?
-    try commandLine.appendAllArguments(.XclangLinker, from: &parsedOptions)
+    try addExtraClangLinkerArgs(to: &commandLine, parsedOptions: &parsedOptions)
 
     if parsedOptions.contains(.v) {
       commandLine.appendFlag("-v")

Tests/SwiftDriverTests/SwiftDriverTests.swift

@@ -1906,6 +1906,29 @@ final class SwiftDriverTests: XCTestCase {
       XCTAssertTrue(cmd.contains(subsequence: [.flag("-Xlinker"), .flag("-rpath=$ORIGIN"), .flag("foo")]))
     }
 
+    do {
+      // Xlinker flags
+      // Ensure that Xlinker flags are passed as such to the clang linker invocation.
+      try withTemporaryDirectory { path in
+        try localFileSystem.writeFileContents(path.appending(components: "wasi", "static-executable-args.lnk")) {
+          $0.send("garbage")
+        }
+        var driver = try Driver(args: commonArgs + ["-emit-executable", "-L", "/tmp", "-Xlinker", "--export-all",
+                                                    "-Xlinker", "-E", "-Xclang-linker", "foo",
+                                                    "-resource-dir", path.pathString,
+                                                    "-target", "wasm32-unknown-wasi"], env: env)
+        let plannedJobs = try driver.planBuild()
+        XCTAssertEqual(plannedJobs.count, 4)
+        let linkJob = plannedJobs[3]
+        let cmd = linkJob.commandLine
+        XCTAssertTrue(cmd.contains(subsequence: [
+          .flag("-Xlinker"), .flag("--export-all"),
+          .flag("-Xlinker"), .flag("-E"),
+          .flag("foo")
+        ]))
+      }
+    }
+
     do {
       var driver = try Driver(args: commonArgs + ["-emit-library", "-no-toolchain-stdlib-rpath",
                                                   "-target", "aarch64-unknown-linux"], env: env)