Fix clang usage in backend.native:tests

For Apple Silicon targets we need to call Clang
1. From toolchain because the one from our distro is too old.
2. With appropriate flags for setting the sysroot.

kotlin-native/backend.native/tests/build.gradle

@@ -4214,7 +4214,7 @@ if (PlatformInfo.isAppleTarget(project)) {
 
         doBeforeBuild {
             mkdir(buildDir)
-            execKonanClang(project.target) {
+            execClangForCompilerTests(project.target) {
                 args "$projectDir/interop/objc/smoke.m"
                 args "-lobjc", '-fobjc-arc'
                 args '-fPIC', '-shared', '-o', "$buildDir/libobjcsmoke.dylib"
@@ -4240,7 +4240,7 @@ if (PlatformInfo.isAppleTarget(project)) {
 
         doBeforeBuild {
             mkdir(buildDir)
-            execKonanClang(project.target) {
+            execClangForCompilerTests(project.target) {
                 args fileTree("$projectDir/interop/objc/tests/") { include '**/*.m' }
                 args "-lobjc", '-fobjc-arc'
                 args '-fPIC', '-shared', '-o', "$buildDir/libobjctests.dylib"
@@ -4260,7 +4260,7 @@ if (PlatformInfo.isAppleTarget(project)) {
 
         doBeforeBuild {
             mkdir(buildDir)
-            execKonanClang(project.target) {
+            execClangForCompilerTests(project.target) {
                 args "$projectDir/interop/objc_with_initializer/objc_misc.m"
                 args "-lobjc", '-fobjc-arc'
                 args '-fPIC', '-shared', '-o', "$buildDir/libobjcmisc.dylib"
@@ -4277,7 +4277,7 @@ if (PlatformInfo.isAppleTarget(project)) {
 
         doBeforeBuild {
             mkdir(buildDir)
-            execKonanClang(project.target) {
+            execClangForCompilerTests(project.target) {
                 args "$projectDir/interop/objc/msg_send/messaging.m"
                 args "-lobjc", '-fobjc-arc'
                 args '-fPIC', '-shared', '-o', "$buildDir/libobjcmessaging.dylib"
@@ -4295,7 +4295,7 @@ if (PlatformInfo.isAppleTarget(project)) {
 
         doBeforeBuild {
             mkdir(buildDir)
-            execKonanClang(project.target) {
+            execClangForCompilerTests(project.target) {
                 args "$projectDir/interop/objc/foreignException/objc_wrap.m"
                 args "-lobjc", '-fobjc-arc'
                 args '-fPIC', '-shared', '-o', "$buildDir/libobjcexception.dylib"
@@ -4314,7 +4314,7 @@ if (PlatformInfo.isAppleTarget(project)) {
 
         doBeforeBuild {
             mkdir(buildDir)
-            execKonanClang(project.target) {
+            execClangForCompilerTests(project.target) {
                 args "$projectDir/interop/objc/foreignException/objc_wrap.m"
                 args "-lobjc", '-fobjc-arc'
                 args '-fPIC', '-shared', '-o', "$buildDir/libobjcexception.dylib"
@@ -4333,7 +4333,7 @@ if (PlatformInfo.isAppleTarget(project)) {
 
         doBeforeBuild {
             mkdir(buildDir)
-            execKonanClang(project.target) {
+            execClangForCompilerTests(project.target) {
                 args "$projectDir/interop/objc/foreignException/objc_wrap.m"
                 args "-lobjc", '-fobjc-arc'
                 args '-fPIC', '-shared', '-o', "$buildDir/libobjcexception.dylib"
@@ -4372,7 +4372,7 @@ if (PlatformInfo.isAppleTarget(project)) {
 
         doBeforeBuild {
             mkdir(buildDir)
-            execKonanClang(project.target) {
+            execClangForCompilerTests(project.target) {
                 args "$projectDir/interop/objc/kt42172/objclib.m"
                 args "-lobjc", '-fobjc-arc'
                 args '-fPIC', '-shared', '-o', "$buildDir/libobjc_kt42172.dylib"

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

@@ -65,7 +65,7 @@ open class GenerateCompilationDatabase @Inject constructor(@Input val target: St
     fun run() {
         val plugin = project.convention.getPlugin(ExecClang::class.java)
         val executable = plugin.resolveExecutable(executable)
-        val args = listOf(executable) + compilerFlags + plugin.konanArgs(target)
+        val args = listOf(executable) + compilerFlags + plugin.clangArgsForCppRuntime(target)
         val entries: List<Entry> = files.map { Entry.create(srcRoot, it, args, outputDir) }
         Entry.writeListTo(outputFile, entries)
     }

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

@@ -30,13 +30,13 @@ class ExecClang(private val project: Project) {
 
     private val platformManager = project.project(":kotlin-native").findProperty("platformManager") as PlatformManager
 
-    private fun konanArgs(target: KonanTarget): List<String> {
+    private fun clangArgsForCppRuntime(target: KonanTarget): List<String> {
         return platformManager.platform(target).clang.clangArgsForKonanSources.asList()
     }
 
-    fun konanArgs(targetName: String?): List<String> {
+    fun clangArgsForCppRuntime(targetName: String?): List<String> {
         val target = platformManager.targetManager(targetName).target
-        return konanArgs(target)
+        return clangArgsForCppRuntime(target)
     }
 
     fun resolveExecutable(executableOrNull: String?): String {
@@ -82,21 +82,46 @@ class ExecClang(private val project: Project) {
     // (nullable, which means host) target name.
 
     fun execKonanClang(target: String?, action: Action<in ExecSpec>): ExecResult {
-        return this.execClang(konanArgs(target), action)
+        return this.execClang(clangArgsForCppRuntime(target), action)
     }
 
     fun execKonanClang(target: KonanTarget, action: Action<in ExecSpec>): ExecResult {
-        return this.execClang(konanArgs(target), action)
+        return this.execClang(clangArgsForCppRuntime(target), action)
     }
 
     fun execKonanClang(target: String?, closure: Closure<in ExecSpec>): ExecResult {
-        return this.execClang(konanArgs(target), closure)
+        return this.execClang(clangArgsForCppRuntime(target), closure)
     }
 
     fun execKonanClang(target: KonanTarget, closure: Closure<in ExecSpec>): ExecResult {
-        return this.execClang(konanArgs(target), closure)
+        return this.execClang(clangArgsForCppRuntime(target), closure)
     }
 
+    /**
+     * Execute Clang the way that produced object file is compatible with
+     * the one that produced by Kotlin/Native for given [target]. It means:
+     * 1. We pass flags that set sysroot.
+     * 2. We call Clang from toolchain in case of Apple target.
+     */
+    fun execClangForCompilerTests(target: KonanTarget, action: Action<in ExecSpec>): ExecResult {
+        val defaultArgs = platformManager.platform(target).clang.clangArgs
+        return project.exec(Action<ExecSpec> {
+            action.execute(this)
+            executable = if (target.family.isAppleFamily) {
+                resolveToolchainExecutable(target, executable)
+            } else {
+                resolveExecutable(executable)
+            }
+            args = defaultArgs + args
+        })
+    }
+
+    /**
+     * @see execClangForCompilerTests
+     */
+    fun execClangForCompilerTests(target: KonanTarget, closure: Closure<in ExecSpec>): ExecResult =
+            execClangForCompilerTests(target, ConfigureUtil.configureUsing(closure))
+
     // The toolchain ones execute clang from the toolchain.
 
     fun execToolchainClang(target: String?, action: Action<in ExecSpec>): ExecResult {
@@ -119,8 +144,6 @@ class ExecClang(private val project: Project) {
         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 {
         return this.execClang(defaultArgs, ConfigureUtil.configureUsing(closure))
     }

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

@@ -376,11 +376,8 @@ fun Project.buildStaticLibrary(cSources: Collection<File>, output: File, objDir:
     val platform = platformManager.platform(testTarget)
 
     objDir.mkdirs()
-    exec {
-        commandLine(platform.clang.clangC(
-                "-c",
-                *cSources.map { it.absolutePath }.toTypedArray()
-        ))
+    ExecClang(project).execClangForCompilerTests(testTarget) {
+        args = listOf("-c", *cSources.map { it.absolutePath }.toTypedArray())
         workingDir(objDir)
     }