Support introspection of parameter names and indices in reflection

compiler/testData/codegen/boxWithStdlib/reflection/parameters/functionParameterNameAndIndex.kt

@@ -0,0 +1,27 @@
+import kotlin.reflect.*
+import kotlin.test.assertEquals
+
+fun foo(bar: String): Int = bar.length()
+
+class A(val c: String) {
+    fun foz(baz: Int) {}
+}
+
+fun Int.qux(zux: String) {}
+
+fun checkParameters(f: KFunction<*>, names: List<String?>) {
+    val params = f.parameters
+    assertEquals(names, params.map { it.name })
+    assertEquals((0..params.size() - 1).toList(), params.mapIndexed { index, element -> index })
+}
+
+fun box(): String {
+    checkParameters(::box, listOf())
+    checkParameters(::foo, listOf("bar"))
+    checkParameters(A::foz, listOf(null, "baz"))
+    checkParameters(Int::qux, listOf(null, "zux"))
+
+    checkParameters(::A, listOf("c"))
+
+    return "OK"
+}

compiler/testData/codegen/boxWithStdlib/reflection/parameters/propertySetter.kt

@@ -0,0 +1,24 @@
+import kotlin.reflect.*
+import kotlin.test.assertEquals
+
+var default: Int = 0
+
+var defaultAnnotated: Int = 0
+    public set
+
+var custom: Int = 0
+    set(myName: Int) {}
+
+fun checkPropertySetterParam(property: KMutableProperty<*>, name: String?) {
+    val parameter = property.setter.parameters.single()
+    assertEquals(0, parameter.index)
+    assertEquals(name, parameter.name)
+}
+
+fun box(): String {
+    checkPropertySetterParam(::default, null)
+    checkPropertySetterParam(::defaultAnnotated, null)
+    checkPropertySetterParam(::custom, "myName")
+
+    return "OK"
+}

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

@@ -3196,6 +3196,27 @@ public class BlackBoxWithStdlibCodegenTestGenerated extends AbstractBlackBoxCode
             }
         }
 
+        @TestMetadata("compiler/testData/codegen/boxWithStdlib/reflection/parameters")
+        @TestDataPath("$PROJECT_ROOT")
+        @RunWith(JUnit3RunnerWithInners.class)
+        public static class Parameters extends AbstractBlackBoxCodegenTest {
+            public void testAllFilesPresentInParameters() throws Exception {
+                JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/boxWithStdlib/reflection/parameters"), Pattern.compile("^(.+)\\.kt$"), true);
+            }
+
+            @TestMetadata("functionParameterNameAndIndex.kt")
+            public void testFunctionParameterNameAndIndex() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithStdlib/reflection/parameters/functionParameterNameAndIndex.kt");
+                doTestWithStdlib(fileName);
+            }
+
+            @TestMetadata("propertySetter.kt")
+            public void testPropertySetter() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithStdlib/reflection/parameters/propertySetter.kt");
+                doTestWithStdlib(fileName);
+            }
+        }
+
         @TestMetadata("compiler/testData/codegen/boxWithStdlib/reflection/properties")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)