Add KParameter.type, KType, KType.isMarkedNullable

core/builtins/src/kotlin/reflect/KParameter.kt

@@ -34,4 +34,9 @@ public interface KParameter {
      * compiled without the debug information, and others.
      */
     public val name: String?
+
+    /**
+     * Type of this parameter.
+     */
+    public val type: KType
 }

core/builtins/src/kotlin/reflect/KType.kt

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package kotlin.reflect
+
+/**
+ * Represents a type. Type is usually either a class with optional type arguments,
+ * or a type parameter of some declaration, plus nullability.
+ */
+public interface KType {
+    /**
+     * `true` if this type was marked nullable in the source code.
+     *
+     * For Kotlin types, it means that `null` value is allowed to be represented by this type.
+     * In practice it means that the type was declared with a question mark at the end.
+     * For non-Kotlin types, it means the type or the symbol which was declared with this type
+     * is annotated with a runtime-retained nullability annotation such as [javax.annotation.Nullable].
+     *
+     * Note that even if [isMarkedNullable] is false, values of the type can still be `null`.
+     * This may happen if it is a type of the type parameter with a nullable upper bound:
+     *
+     * ```
+     * fun foo<T>(t: T) {
+     *     // isMarkedNullable == false for t's type, but t can be null here
+     * }
+     * ```
+     */
+    public val isMarkedNullable: Boolean
+}