Resolve Swift compatibility libraries at iOS link time

gradle-plugins/compose/build.gradle.kts

@@ -68,6 +68,7 @@ dependencies {
     }
 
     compileOnly(gradleApi())
+    compileOnly(gradleKotlinDsl())
     compileOnly(localGroovy())
     compileOnly(kotlin("gradle-plugin"))
     compileOnly(kotlin("native-utils"))

gradle-plugins/compose/src/main/kotlin/org/jetbrains/compose/ComposePlugin.kt

@@ -55,6 +55,7 @@ abstract class ComposePlugin : Plugin<Project> {
         project.configureWeb()
 
         project.configureRuntimeLibrariesCompatibilityCheck(dependencyCompatibilityExtension)
+        project.configureSwiftCompatibilityLinking()
 
         project.afterEvaluate {
             configureDesktop(project, desktopExtension)

gradle-plugins/compose/src/main/kotlin/org/jetbrains/compose/SwiftCompatibilityLinking.kt

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2026 JetBrains s.r.o. and respective authors and developers.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE.txt file.
+ */
+
+package org.jetbrains.compose
+
+import org.gradle.api.Project
+import org.gradle.internal.os.OperatingSystem
+import org.gradle.kotlin.dsl.withType
+import org.jetbrains.compose.internal.KOTLIN_MPP_PLUGIN_ID
+import org.jetbrains.compose.internal.mppExt
+import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinNativeTarget
+import org.jetbrains.kotlin.gradle.plugin.mpp.NativeBinary
+import org.jetbrains.kotlin.konan.target.KonanTarget
+import java.io.File
+
+/**
+ * Adds the active Xcode toolchain's Swift library directory to iOS native links.
+ *
+ * Kotlin/Native does not currently add this directory itself (KT-69793). It is resolved from the active
+ * toolchain at final link time; Swift auto-link metadata selects the needed runtime and compatibility libraries.
+ */
+internal fun Project.configureSwiftCompatibilityLinking() {
+    plugins.withId(KOTLIN_MPP_PLUGIN_ID) {
+        mppExt.targets.withType<KotlinNativeTarget>().all { target ->
+            target.configureSwiftCompatibilityLinking()
+        }
+    }
+}
+
+private fun KotlinNativeTarget.configureSwiftCompatibilityLinking() {
+    if (!OperatingSystem.current().isMacOsX) return
+
+    val sdkName =
+        when (konanTarget) {
+            KonanTarget.IOS_ARM64 -> "iphoneos"
+            KonanTarget.IOS_X64,
+            KonanTarget.IOS_SIMULATOR_ARM64 -> "iphonesimulator"
+            else -> return
+        }
+    val swiftCompatibilityLibraryDir =
+        project.providers
+            .exec { spec -> spec.commandLine("xcrun", "--sdk", sdkName, "--show-toolchain-path") }
+            .standardOutput
+            .asText
+            .map { toolchainPath ->
+                File(toolchainPath.trim())
+                    .resolve("usr/lib/swift/$sdkName")
+                    .absolutePath
+            }
+
+    binaries.withType<NativeBinary>().all { binary ->
+        binary.linkTaskProvider.configure { linkTask ->
+            linkTask.toolOptions.freeCompilerArgs.addAll(
+                swiftCompatibilityLibraryDir.map { libraryDir ->
+                    listOf("-linker-option", "-L$libraryDir")
+                }
+            )
+        }
+    }
+}