backend/tests: add cast_null and unchecked_cast3

backend.native/tests/build.gradle

@@ -212,6 +212,11 @@ task cast_simple(type: RunKonanTest) {
     source = "codegen/basics/cast_simple.kt"
 }
 
+task cast_null(type: RunKonanTest) {
+    goldValue = "Ok\n"
+    source = "codegen/basics/cast_null.kt"
+}
+
 task unchecked_cast1(type: RunKonanTest) {
     goldValue = "17\n17\n42\n42\n"
     source = "codegen/basics/unchecked_cast1.kt"
@@ -223,6 +228,11 @@ task unchecked_cast2(type: RunKonanTest) {
     source = "codegen/basics/unchecked_cast2.kt"
 }
 
+task unchecked_cast3(type: RunKonanTest) {
+    goldValue = "Ok\n"
+    source = "codegen/basics/unchecked_cast3.kt"
+}
+
 task null_check(type: RunKonanTest) {
     source = "codegen/basics/null_check.kt"
 }

backend.native/tests/codegen/basics/cast_null.kt

@@ -0,0 +1,48 @@
+fun main(args: Array<String>) {
+    testCast(null, false)
+    testCastToNullable(null, true)
+    testCastToNullable(Test(), true)
+    testCastToNullable("", false)
+    testCastNotNullableToNullable(Test(), true)
+    testCastNotNullableToNullable("", false)
+
+    println("Ok")
+}
+
+class Test
+
+fun ensure(b: Boolean) {
+    if (!b) {
+        println("Error")
+    }
+}
+
+fun testCast(x: Any?, expectSuccess: Boolean) {
+    try {
+        x as Test
+    } catch (e: Throwable) {
+        ensure(!expectSuccess)
+        return
+    }
+    ensure(expectSuccess)
+}
+
+fun testCastToNullable(x: Any?, expectSuccess: Boolean) {
+    try {
+        x as Test?
+    } catch (e: Throwable) {
+        ensure(!expectSuccess)
+        return
+    }
+    ensure(expectSuccess)
+}
+
+fun testCastNotNullableToNullable(x: Any, expectSuccess: Boolean) {
+    try {
+        x as Test?
+    } catch (e: Throwable) {
+        ensure(!expectSuccess)
+        return
+    }
+    ensure(expectSuccess)
+}

backend.native/tests/codegen/basics/unchecked_cast3.kt

@@ -0,0 +1,35 @@
+fun main(args: Array<String>) {
+    testCast<Test>(Test(), true)
+    testCast<Test>(null, false)
+    testCastToNullable<Test>(null, true)
+
+    println("Ok")
+}
+
+class Test
+
+fun ensure(b: Boolean) {
+    if (!b) {
+        println("Error")
+    }
+}
+
+fun <T : Any> testCast(x: Any?, expectSuccess: Boolean) {
+    try {
+        x as T
+    } catch (e: Throwable) {
+        ensure(!expectSuccess)
+        return
+    }
+    ensure(expectSuccess)
+}
+
+fun <T : Any> testCastToNullable(x: Any?, expectSuccess: Boolean) {
+    try {
+        x as T?
+    } catch (e: Throwable) {
+        ensure(!expectSuccess)
+        return
+    }
+    ensure(expectSuccess)
+}