Use toolchain clang for runtime tests on mac (#4632)

kotlin-native/build-tools/src/main/kotlin/org/jetbrains/kotlin/ExecClang.kt

@@ -50,6 +50,22 @@ class ExecClang(private val project: Project) {
         }
     }
 
+    fun resolveToolchainExecutable(target: KonanTarget, executableOrNull: String?): String {
+        val executable = executableOrNull ?: "clang"
+
+        if (listOf("clang", "clang++").contains(executable)) {
+            // TODO: This is copied from `BitcodeCompiler`. Consider sharing the code instead.
+            val platform = platformManager.platform(target)
+            return if (target.family.isAppleFamily) {
+                "${platform.absoluteTargetToolchain}/usr/bin/$executable"
+            } else {
+                "${platform.absoluteTargetToolchain}/bin/$executable"
+            }
+        } else {
+            throw GradleException("unsupported clang executable: $executable")
+        }
+    }
+
     // The bare ones invoke clang with system default sysroot.
 
     fun execBareClang(action: Action<in ExecSpec>): ExecResult {
@@ -81,6 +97,30 @@ class ExecClang(private val project: Project) {
         return this.execClang(konanArgs(target), closure)
     }
 
+    // The toolchain ones execute clang from the toolchain.
+
+    fun execToolchainClang(target: String?, action: Action<in ExecSpec>): ExecResult {
+        return this.execToolchainClang(platformManager.targetManager(target).target, action)
+    }
+
+    fun execToolchainClang(target: String?, closure: Closure<in ExecSpec>): ExecResult {
+        return this.execToolchainClang(platformManager.targetManager(target).target, ConfigureUtil.configureUsing(closure))
+    }
+
+    fun execToolchainClang(target: KonanTarget, action: Action<in ExecSpec>): ExecResult {
+        val extendedAction = Action<ExecSpec> { execSpec ->
+            action.execute(execSpec)
+            execSpec.apply {
+                executable = resolveToolchainExecutable(target, executable)
+            }
+        }
+        return project.exec(extendedAction)
+    }
+
+    fun execToolchainClang(target: KonanTarget, closure: Closure<in ExecSpec>): ExecResult {
+        return this.execToolchainClang(target, ConfigureUtil.configureUsing(closure))
+    }
+
     // These ones are private, so one has to choose either Bare or Konan.
 
     private fun execClang(defaultArgs: List<String>, closure: Closure<in ExecSpec>): ExecResult {

kotlin-native/build-tools/src/main/kotlin/org/jetbrains/kotlin/testing/native/NativeTest.kt

@@ -17,10 +17,10 @@ import org.jetbrains.kotlin.konan.target.*
 
 open class CompileNativeTest @Inject constructor(
         @InputFile val inputFile: File,
-        @Input val target: String
+        @Input val target: KonanTarget,
 ) : DefaultTask() {
     @OutputFile
-    var outputFile = project.buildDir.resolve("bin/test/$target/${inputFile.nameWithoutExtension}.o")
+    var outputFile = project.buildDir.resolve("bin/test/${target.name}/${inputFile.nameWithoutExtension}.o")
 
     @Input
     val clangArgs = mutableListOf<String>()
@@ -28,9 +28,16 @@ open class CompileNativeTest @Inject constructor(
     @TaskAction
     fun compile() {
         val plugin = project.convention.getPlugin(ExecClang::class.java)
-        plugin.execBareClang {
-            it.executable = "clang++"
-            it.args = clangArgs + listOf(inputFile.absolutePath, "-o", outputFile.absolutePath)
+        if (target.family.isAppleFamily) {
+            plugin.execToolchainClang(target) {
+                it.executable = "clang++"
+                it.args = clangArgs + listOf(inputFile.absolutePath, "-o", outputFile.absolutePath)
+            }
+        } else {
+            plugin.execBareClang {
+                it.executable = "clang++"
+                it.args = clangArgs + listOf(inputFile.absolutePath, "-o", outputFile.absolutePath)
+            }
         }
     }
 }
@@ -218,7 +225,7 @@ fun createTestTask(
             "${testTaskName}Compile",
             CompileNativeTest::class.java,
             llvmLinkTask.outputFile,
-            target
+            konanTarget,
     ).apply {
         dependsOn(llvmLinkTask)
         clangArgs.addAll(clangFlags.clangFlags)