Reflection: add KTypeProjection and KType.arguments

#KT-8998 In Progress

compiler/testData/codegen/box/reflection/mapping/types/genericArrayElementType.kt

@@ -0,0 +1,34 @@
+// WITH_REFLECT
+// FULL_JDK
+
+import java.lang.reflect.ParameterizedType
+import kotlin.reflect.jvm.javaType
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+class Bar
+fun arrayOfInvBar(): Array<Bar> = null!!
+fun arrayOfInBar(): Array<in Bar> = null!!
+fun arrayOfOutBar(): Array<out Bar> = null!!
+
+fun arrayOfInvList(): Array<List<String>> = null!!
+fun arrayOfInList(): Array<in List<String>> = null!!
+fun arrayOfOutList(): Array<out List<String>> = null!!
+
+fun box(): String {
+    // NB: in "Array<in X>", Java type of X is always Any::class.java because this is the JVM signature generated by the compiler
+
+    assertEquals(Bar::class.java, ::arrayOfInvBar.returnType.arguments.single().type!!.javaType)
+    assertEquals(Any::class.java, ::arrayOfInBar.returnType.arguments.single().type!!.javaType)
+    assertEquals(Bar::class.java, ::arrayOfOutBar.returnType.arguments.single().type!!.javaType)
+
+    val invList = ::arrayOfInvList.returnType.arguments.single().type!!.javaType
+    assertTrue(invList is ParameterizedType && invList.rawType == List::class.java, invList.toString())
+
+    assertEquals(Any::class.java, ::arrayOfInList.returnType.arguments.single().type!!.javaType)
+
+    val outList = ::arrayOfOutList.returnType.arguments.single().type!!.javaType
+    assertTrue(outList is ParameterizedType && outList.rawType == List::class.java, outList.toString())
+
+    return "OK"
+}

compiler/testData/codegen/box/reflection/mapping/types/parameterizedTypeArgument.kt

@@ -0,0 +1,22 @@
+// WITH_REFLECT
+
+import kotlin.reflect.jvm.javaType
+import kotlin.test.assertEquals
+
+fun listOfStrings(): List<String> = null!!
+
+class Foo<T>
+class Bar
+fun fooOfInvBar(): Foo<Bar> = null!!
+fun fooOfInBar(): Foo<in Bar> = null!!
+fun fooOfOutBar(): Foo<out Bar> = null!!
+
+fun box(): String {
+    assertEquals(String::class.java, ::listOfStrings.returnType.arguments.single().type!!.javaType)
+
+    assertEquals(Bar::class.java, ::fooOfInvBar.returnType.arguments.single().type!!.javaType)
+    assertEquals(Bar::class.java, ::fooOfInBar.returnType.arguments.single().type!!.javaType)
+    assertEquals(Bar::class.java, ::fooOfOutBar.returnType.arguments.single().type!!.javaType)
+
+    return "OK"
+}

compiler/testData/codegen/box/reflection/mapping/types/rawTypeArgument.kt

@@ -0,0 +1,19 @@
+// WITH_REFLECT
+// FILE: J.java
+
+import java.util.List;
+
+public interface J {
+    List foo();
+}
+
+// FILE: K.kt
+
+import kotlin.reflect.jvm.javaType
+import kotlin.test.assertEquals
+
+fun box(): String {
+    assertEquals(Any::class.java, J::foo.returnType.arguments.single().type!!.javaType)
+
+    return "OK"
+}

compiler/testData/codegen/box/reflection/types/typeArguments.kt

@@ -0,0 +1,42 @@
+// WITH_REFLECT
+
+import kotlin.reflect.KTypeProjection
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+fun string(): String = null!!
+
+class Fourple<A, B, C, D>
+fun projections(): Fourple<String, in String, out String, *> = null!!
+
+fun array(): Array<out Number> = null!!
+
+fun list(): List<String> = null!!
+
+fun box(): String {
+    val string = ::string.returnType
+    assertEquals(listOf(), string.arguments)
+
+    assertEquals(
+            listOf(
+                    KTypeProjection.Invariant(string),
+                    KTypeProjection.In(string),
+                    KTypeProjection.Out(string),
+                    KTypeProjection.Star
+            ),
+            ::projections.returnType.arguments
+    )
+    assertEquals(
+            listOf(string, string, string, null),
+            ::projections.returnType.arguments.map(KTypeProjection::type)
+    )
+
+    val outNumber = ::array.returnType.arguments.single()
+    assertTrue(outNumber is KTypeProjection.Out)
+    assertEquals(Number::class, outNumber.type?.classifier)
+
+    // There should be no use-site projection, despite the fact that the corresponding parameter has 'out' variance
+    assertTrue(::list.returnType.arguments.single() is KTypeProjection.Invariant)
+
+    return "OK"
+}

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -12431,6 +12431,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                     doTest(fileName);
                 }
 
+                @TestMetadata("genericArrayElementType.kt")
+                public void testGenericArrayElementType() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/reflection/mapping/types/genericArrayElementType.kt");
+                    doTest(fileName);
+                }
+
                 @TestMetadata("memberFunctions.kt")
                 public void testMemberFunctions() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/reflection/mapping/types/memberFunctions.kt");
@@ -12443,6 +12449,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                     doTest(fileName);
                 }
 
+                @TestMetadata("parameterizedTypeArgument.kt")
+                public void testParameterizedTypeArgument() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/reflection/mapping/types/parameterizedTypeArgument.kt");
+                    doTest(fileName);
+                }
+
                 @TestMetadata("parameterizedTypes.kt")
                 public void testParameterizedTypes() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/reflection/mapping/types/parameterizedTypes.kt");
@@ -12455,6 +12467,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                     doTest(fileName);
                 }
 
+                @TestMetadata("rawTypeArgument.kt")
+                public void testRawTypeArgument() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/reflection/mapping/types/rawTypeArgument.kt");
+                    doTest(fileName);
+                }
+
                 @TestMetadata("topLevelFunctions.kt")
                 public void testTopLevelFunctions() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/reflection/mapping/types/topLevelFunctions.kt");
@@ -12968,6 +12986,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/reflection/types/platformTypeToString.kt");
                 doTest(fileName);
             }
+
+            @TestMetadata("typeArguments.kt")
+            public void testTypeArguments() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/reflection/types/typeArguments.kt");
+                doTest(fileName);
+            }
         }
     }