Support KClass.simpleName and built-in class literals

compiler/backend/src/org/jetbrains/kotlin/codegen/ExpressionCodegen.java

@@ -2719,8 +2719,9 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> implem
             @Override
             public Unit invoke(InstructionAdapter v) {
                 Type classAsmType = typeMapper.mapClass(descriptor);
-                if (descriptor instanceof JavaClassDescriptor) {
-                    v.aconst(classAsmType);
+                ModuleDescriptor module = DescriptorUtils.getContainingModule(descriptor);
+                if (descriptor instanceof JavaClassDescriptor || module == module.getBuiltIns().getBuiltInsModule()) {
+                    putJavaLangClassInstance(v, classAsmType);
                     v.invokestatic(REFLECTION, "foreignKotlinClass", Type.getMethodDescriptor(K_CLASS_TYPE, getType(Class.class)), false);
                 }
                 else {

compiler/testData/codegen/boxAgainstJava/reflection/classLiterals/javaClassLiteral.java

@@ -0,0 +1,2 @@
+public class javaClassLiteral {
+}

compiler/testData/codegen/boxAgainstJava/reflection/classLiterals/javaClassLiteral.kt

@@ -0,0 +1,8 @@
+import javaClassLiteral as J
+
+fun box(): String {
+    val j = J::class
+    if (j.simpleName != "javaClassLiteral") return "Fail: ${j.simpleName}"
+
+    return "OK"
+}

compiler/testData/codegen/boxWithStdlib/reflection/classLiterals/builtinClassLiterals.kt

@@ -0,0 +1,22 @@
+import kotlin.test.assertEquals
+
+fun box(): String {
+    assertEquals("Any", Any::class.simpleName)
+    assertEquals("String", String::class.simpleName)
+    assertEquals("CharSequence", CharSequence::class.simpleName)
+    assertEquals("Number", Number::class.simpleName)
+    assertEquals("Int", Int::class.simpleName)
+    assertEquals("Long", Long::class.simpleName)
+
+    assertEquals("Default", Int.Default::class.simpleName)
+    assertEquals("Default", Double.Default::class.simpleName)
+
+    assertEquals("IntRange", IntRange::class.simpleName)
+
+    assertEquals("List", List::class.simpleName)
+
+    // TODO: this is wrong but should be fixed
+    assertEquals("List", MutableList::class.simpleName)
+
+    return "OK"
+}

compiler/testData/codegen/boxWithStdlib/reflection/classLiterals/classSimpleName.kt

@@ -0,0 +1,14 @@
+class Klass
+
+fun box(): String {
+    val x = Klass::class
+    if (x.simpleName != "Klass") return "Fail x: ${x.simpleName}"
+
+    val y = java.util.Date::class
+    if (y.simpleName != "Date") return "Fail y: ${y.simpleName}"
+
+    val z = kotlin.jvm.internal.KotlinSyntheticClass.Kind::class
+    if (z.simpleName != "Kind") return "Fail z: ${z.simpleName}"
+
+    return "OK"
+}

compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxAgainstJavaCodegenTestGenerated.java

@@ -331,6 +331,7 @@ public class BlackBoxAgainstJavaCodegenTestGenerated extends AbstractBlackBoxCod
     @TestMetadata("compiler/testData/codegen/boxAgainstJava/reflection")
     @TestDataPath("$PROJECT_ROOT")
     @InnerTestClasses({
+            Reflection.ClassLiterals.class,
             Reflection.Mapping.class,
             Reflection.Properties.class,
     })
@@ -340,6 +341,21 @@ public class BlackBoxAgainstJavaCodegenTestGenerated extends AbstractBlackBoxCod
             JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/boxAgainstJava/reflection"), Pattern.compile("^(.+)\\.kt$"), true);
         }
 
+        @TestMetadata("compiler/testData/codegen/boxAgainstJava/reflection/classLiterals")
+        @TestDataPath("$PROJECT_ROOT")
+        @RunWith(JUnit3RunnerWithInners.class)
+        public static class ClassLiterals extends AbstractBlackBoxCodegenTest {
+            public void testAllFilesPresentInClassLiterals() throws Exception {
+                JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/boxAgainstJava/reflection/classLiterals"), Pattern.compile("^(.+)\\.kt$"), true);
+            }
+
+            @TestMetadata("javaClassLiteral.kt")
+            public void testJavaClassLiteral() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxAgainstJava/reflection/classLiterals/javaClassLiteral.kt");
+                doTestAgainstJava(fileName);
+            }
+        }
+
         @TestMetadata("compiler/testData/codegen/boxAgainstJava/reflection/mapping")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)

compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxWithStdlibCodegenTestGenerated.java

@@ -2545,6 +2545,18 @@ public class BlackBoxWithStdlibCodegenTestGenerated extends AbstractBlackBoxCode
                 JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/boxWithStdlib/reflection/classLiterals"), Pattern.compile("^(.+)\\.kt$"), true);
             }
 
+            @TestMetadata("builtinClassLiterals.kt")
+            public void testBuiltinClassLiterals() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithStdlib/reflection/classLiterals/builtinClassLiterals.kt");
+                doTestWithStdlib(fileName);
+            }
+
+            @TestMetadata("classSimpleName.kt")
+            public void testClassSimpleName() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithStdlib/reflection/classLiterals/classSimpleName.kt");
+                doTestWithStdlib(fileName);
+            }
+
             @TestMetadata("simpleClassLiteral.kt")
             public void testSimpleClassLiteral() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithStdlib/reflection/classLiterals/simpleClassLiteral.kt");

core/reflection.jvm/src/kotlin/reflect/jvm/internal/KClassImpl.kt

@@ -38,6 +38,11 @@ class KClassImpl<T>(override val jClass: Class<T>) : KCallableContainerImpl(), K
 
     override val scope: JetScope get() = descriptor.getDefaultType().getMemberScope()
 
+    override val simpleName: String? get() {
+        val name = descriptor.getName()
+        return if (name.isSpecial()) null else name.asString()
+    }
+
     override fun getProperties(): Collection<KMemberProperty<T, *>> {
         return scope.getAllDescriptors().stream()
                 .filterIsInstance<PropertyDescriptor>()

core/reflection/src/kotlin/reflect/KClass.kt

@@ -17,6 +17,8 @@
 package kotlin.reflect
 
 public trait KClass<T> {
+    public val simpleName: String?
+
     public fun getProperties(): Collection<KMemberProperty<T, *>>
 
     public fun getExtensionProperties(): Collection<KMemberExtensionProperty<T, *, *>>