Reflection: add API for declaration modifiers

#KT-10447 Fixed

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

@@ -62,4 +62,19 @@ public interface KCallable<out R> : KAnnotatedElement {
      * or its type does not match the type of the provided value, an exception is thrown.
      */
     public fun callBy(args: Map<KParameter, Any?>): R
+
+    /**
+     * `true` if this callable is `final`.
+     */
+    public val isFinal: Boolean
+
+    /**
+     * `true` if this callable is `open`.
+     */
+    public val isOpen: Boolean
+
+    /**
+     * `true` if this callable is `abstract`.
+     */
+    public val isAbstract: Boolean
 }

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

@@ -73,6 +73,49 @@ public interface KClass<T : Any> : KDeclarationContainer, KAnnotatedElement, KCl
      */
     public val supertypes: List<KType>
 
+    /**
+     * `true` if this class is `final`.
+     */
+    public val isFinal: Boolean
+
+    /**
+     * `true` if this class is `open`.
+     */
+    public val isOpen: Boolean
+
+    /**
+     * `true` if this class is `abstract`.
+     */
+    public val isAbstract: Boolean
+
+    /**
+     * `true` if this class is `sealed`.
+     * See the [Kotlin language documentation](https://kotlinlang.org/docs/reference/classes.html#sealed-classes)
+     * for more information.
+     */
+    public val isSealed: Boolean
+
+    /**
+     * `true` if this class is a data class.
+     * See the [Kotlin language documentation](https://kotlinlang.org/docs/reference/data-classes.html)
+     * for more information.
+     */
+    public val isData: Boolean
+
+    /**
+     * `true` if this class is an inner class.
+     * See the [Kotlin language documentation](https://kotlinlang.org/docs/reference/nested-classes.html#inner-classes)
+     * for more information.
+     */
+    public val isInner: Boolean
+
+    /**
+     * `true` if this class is a companion object.
+     * See the [Kotlin language documentation](https://kotlinlang.org/docs/reference/object-declarations.html#companion-objects)
+     * for more information.
+     */
+    public val isCompanion: Boolean
+
     /**
      * Returns `true` if [other] is a [KClass] instance representing the same class on a given platform.
      *

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

@@ -19,4 +19,44 @@ package kotlin.reflect
 /**
  * Represents a function with introspection capabilities.
  */
-public interface KFunction<out R> : KCallable<R>, Function<R>
+public interface KFunction<out R> : KCallable<R>, Function<R> {
+    /**
+     * `true` if this function is `inline`.
+     * See the [Kotlin language documentation](https://kotlinlang.org/docs/reference/inline-functions.html)
+     * for more information.
+     */
+    public val isInline: Boolean
+
+    /**
+     * `true` if this function is `external`.
+     * See the [Kotlin language documentation](https://kotlinlang.org/docs/reference/java-interop.html#using-jni-with-kotlin)
+     * for more information.
+     */
+    public val isExternal: Boolean
+
+    /**
+     * `true` if this function is `operator`.
+     * See the [Kotlin language documentation](https://kotlinlang.org/docs/reference/operator-overloading.html)
+     * for more information.
+     */
+    public val isOperator: Boolean
+
+    /**
+     * `true` if this function is `infix`.
+     * See the [Kotlin language documentation](https://kotlinlang.org/docs/reference/functions.html#infix-notation)
+     * for more information.
+     */
+    public val isInfix: Boolean
+
+    /**
+     * `true` if this function is `tailrec`.
+     * See the [Kotlin language documentation](https://kotlinlang.org/docs/reference/functions.html#tail-recursive-functions)
+     * for more information.
+     */
+    public val isTailrec: Boolean
+
+    /**
+     * `true` if this is a suspending function.
+     */
+    public val isSuspend: Boolean
+}

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

@@ -69,4 +69,30 @@ public interface KParameter : KAnnotatedElement {
      * 2. The parameter is declared in a member function and one of the corresponding parameters in the super functions is optional.
      */
     public val isOptional: Boolean
+
+    /**
+     * `true` if this parameter is `vararg`.
+     * See the [Kotlin language documentation](https://kotlinlang.org/docs/reference/functions.html#variable-number-of-arguments-varargs)
+     * for more information.
+     */
+    public val isVararg: Boolean
+
+    /**
+     * `true` if this parameter is `noinline`.
+     * See the [Kotlin language documentation](https://kotlinlang.org/docs/reference/inline-functions.html#noinline)
+     * for more information.
+     */
+    public val isNoinline: Boolean
+
+    /**
+     * `true` if this parameter is `crossinline`.
+     * See the [Kotlin language documentation](https://kotlinlang.org/docs/reference/inline-functions.html#non-local-returns)
+     * for more information.
+     */
+    public val isCrossinline: Boolean
+
+    /**
+     * `true` if this parameter is `coroutine`.
+     */
+    public val isCoroutine: Boolean
 }

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

@@ -25,6 +25,20 @@ package kotlin.reflect
  * @param R the type of the property.
  */
 public interface KProperty<out R> : KCallable<R> {
+    /**
+     * `true` if this property is `lateinit`.
+     * See the [Kotlin language documentation](https://kotlinlang.org/docs/reference/properties.html#late-initialized-properties)
+     * for more information.
+     */
+    public val isLateinit: Boolean
+
+    /**
+     * `true` if this property is `const`.
+     * See the [Kotlin language documentation](https://kotlinlang.org/docs/reference/properties.html#compile-time-constants)
+     * for more information.
+     */
+    public val isConst: Boolean
+
     /** The getter of this property, used to obtain the value of the property. */
     public val getter: Getter<R>
 

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

@@ -40,4 +40,11 @@ public interface KTypeParameter : KClassifier {
      * for more information.
      */
     public val variance: KVariance
+
+    /**
+     * `true` if this type parameter is `reified`.
+     * See the [Kotlin language documentation](https://kotlinlang.org/docs/reference/inline-functions.html#reified-type-parameters)
+     * for more information.
+     */
+    public val isReified: Boolean
 }

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

@@ -17,6 +17,7 @@
 package kotlin.reflect.jvm.internal
 
 import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor
+import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.descriptors.annotations.Annotated
 import java.lang.reflect.Type
 import java.util.*
@@ -62,6 +63,15 @@ internal interface KCallableImpl<out R> : KCallable<R>, KAnnotatedElementImpl {
     override val typeParameters: List<KTypeParameter>
         get() = descriptor.typeParameters.map(::KTypeParameterImpl)
 
+    override val isFinal: Boolean
+        get() = descriptor.modality == Modality.FINAL
+
+    override val isOpen: Boolean
+        get() = descriptor.modality == Modality.OPEN
+
+    override val isAbstract: Boolean
+        get() = descriptor.modality == Modality.ABSTRACT
+
     @Suppress("UNCHECKED_CAST")
     override fun call(vararg args: Any?): R = reflectionCall {
         return caller.call(args) as R

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

@@ -170,6 +170,27 @@ internal class KClassImpl<T : Any>(override val jClass: Class<T>) :
             }
         }
 
+    override val isFinal: Boolean
+        get() = descriptor.modality == Modality.FINAL
+
+    override val isOpen: Boolean
+        get() = descriptor.modality == Modality.OPEN
+
+    override val isAbstract: Boolean
+        get() = descriptor.modality == Modality.ABSTRACT
+
+    override val isSealed: Boolean
+        get() = descriptor.modality == Modality.SEALED
+
+    override val isData: Boolean
+        get() = descriptor.isData
+
+    override val isInner: Boolean
+        get() = descriptor.isInner
+
+    override val isCompanion: Boolean
+        get() = descriptor.isCompanionObject
+
     override fun equals(other: Any?): Boolean =
             other is KClassImpl<*> && jClass == other.jClass
 

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

@@ -109,6 +109,24 @@ internal open class KFunctionImpl protected constructor(
                (if (descriptor.extensionReceiverParameter != null) 1 else 0)
     }
 
+    override val isInline: Boolean
+        get() = descriptor.isInline
+
+    override val isExternal: Boolean
+        get() = descriptor.isExternal
+
+    override val isOperator: Boolean
+        get() = descriptor.isOperator
+
+    override val isInfix: Boolean
+        get() = descriptor.isInfix
+
+    override val isTailrec: Boolean
+        get() = descriptor.isTailrec
+
+    override val isSuspend: Boolean
+        get() = descriptor.isSuspend
+
     override fun equals(other: Any?): Boolean {
         val that = other.asKFunctionImpl() ?: return false
         return container == that.container && name == that.name && signature == that.signature

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

@@ -46,6 +46,18 @@ internal class KParameterImpl(
     override val isOptional: Boolean
         get() = (descriptor as? ValueParameterDescriptor)?.hasDefaultValue() ?: false
 
+    override val isVararg: Boolean
+        get() = descriptor.let { it is ValueParameterDescriptor && it.varargElementType != null }
+
+    override val isNoinline: Boolean
+        get() = descriptor.let { it is ValueParameterDescriptor && it.isNoinline }
+
+    override val isCrossinline: Boolean
+        get() = descriptor.let { it is ValueParameterDescriptor && it.isCrossinline }
+
+    override val isCoroutine: Boolean
+        get() = descriptor.let { it is ValueParameterDescriptor && it.isCoroutine }
+
     override fun equals(other: Any?) =
             other is KParameterImpl && callable == other.callable && descriptor == other.descriptor
 

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

@@ -42,10 +42,40 @@ internal interface KPropertyImpl<out R> : KProperty<R>, KCallableImpl<R> {
 
     override val defaultCaller: FunctionCaller<*>? get() = getter.defaultCaller
 
+    override val isLateinit: Boolean
+        get() = descriptor.isLateInit
+
+    override val isConst: Boolean
+        get() = descriptor.isConst
+
     abstract class Accessor<out R> : KProperty.Accessor<R> {
         abstract override val property: KPropertyImpl<R>
 
         internal abstract val descriptor: PropertyAccessorDescriptor
+
+        @Suppress("unused") // Used as an implementation of KFunction#isInline in subclasses
+        val isInline: Boolean
+            get() = descriptor.isInline
+
+        @Suppress("unused")
+        val isExternal: Boolean
+            get() = descriptor.isExternal
+
+        @Suppress("unused")
+        val isOperator: Boolean
+            get() = descriptor.isOperator
+
+        @Suppress("unused")
+        val isInfix: Boolean
+            get() = descriptor.isInfix
+
+        @Suppress("unused")
+        val isTailrec: Boolean
+            get() = descriptor.isTailrec
+
+        @Suppress("unused")
+        val isSuspend: Boolean
+            get() = descriptor.isSuspend
     }
 
     abstract class Getter<out R> : Accessor<R>(), KProperty.Getter<R>, KCallableImpl<R> {

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

@@ -40,6 +40,9 @@ internal class KTypeParameterImpl(override val descriptor: TypeParameterDescript
             Variance.OUT_VARIANCE -> KVariance.OUT
         }
 
+    override val isReified: Boolean
+        get() = descriptor.isReified
+
     override fun equals(other: Any?) =
             other is KTypeParameterImpl && descriptor == other.descriptor
 

core/runtime.jvm/src/kotlin/jvm/internal/CallableReference.java

@@ -99,6 +99,21 @@ public abstract class CallableReference implements KCallable {
         return getReflected().callBy(args);
     }
 
+    @Override
+    public boolean isFinal() {
+        return getReflected().isFinal();
+    }
+
+    @Override
+    public boolean isOpen() {
+        return getReflected().isOpen();
+    }
+
+    @Override
+    public boolean isAbstract() {
+        return getReflected().isAbstract();
+    }
+
     public KCallable compute() {
         if (reflected == null) {
             reflected = computeReflected();

core/runtime.jvm/src/kotlin/jvm/internal/ClassReference.kt

@@ -48,6 +48,27 @@ class ClassReference(override val jClass: Class<*>) : KClass<Any>, ClassBasedDec
     override val supertypes: List<KType>
         get() = error()
 
+    override val isFinal: Boolean
+        get() = error()
+
+    override val isOpen: Boolean
+        get() = error()
+
+    override val isAbstract: Boolean
+        get() = error()
+
+    override val isSealed: Boolean
+        get() = error()
+
+    override val isData: Boolean
+        get() = error()
+
+    override val isInner: Boolean
+        get() = error()
+
+    override val isCompanion: Boolean
+        get() = error()
+
     private fun error(): Nothing = throw KotlinReflectionNotSupportedError()
 
     override fun equals(other: Any?) =

core/runtime.jvm/src/kotlin/jvm/internal/FunctionReference.java

@@ -84,6 +84,51 @@ public class FunctionReference extends FunctionImpl implements KFunction {
         return getReflected().callBy(args);
     }
 
+    @Override
+    public boolean isFinal() {
+        return getReflected().isFinal();
+    }
+
+    @Override
+    public boolean isOpen() {
+        return getReflected().isOpen();
+    }
+
+    @Override
+    public boolean isAbstract() {
+        return getReflected().isAbstract();
+    }
+
+    @Override
+    public boolean isInline() {
+        return getReflected().isInline();
+    }
+
+    @Override
+    public boolean isExternal() {
+        return getReflected().isExternal();
+    }
+
+    @Override
+    public boolean isOperator() {
+        return getReflected().isOperator();
+    }
+
+    @Override
+    public boolean isInfix() {
+        return getReflected().isInfix();
+    }
+
+    @Override
+    public boolean isTailrec() {
+        return getReflected().isTailrec();
+    }
+
+    @Override
+    public boolean isSuspend() {
+        return getReflected().isSuspend();
+    }
+
     @Override
     public boolean equals(Object obj) {
         if (obj == this) return true;

core/runtime.jvm/src/kotlin/jvm/internal/PropertyReference.java

@@ -19,6 +19,21 @@ package kotlin.jvm.internal;
 import kotlin.reflect.KProperty;
 
 public abstract class PropertyReference extends CallableReference implements KProperty {
+    @Override
+    protected KProperty getReflected() {
+        return (KProperty) super.getReflected();
+    }
+
+    @Override
+    public boolean isLateinit() {
+        return getReflected().isLateinit();
+    }
+
+    @Override
+    public boolean isConst() {
+        return getReflected().isConst();
+    }
+
     @Override
     public boolean equals(Object obj) {
         if (obj == this) return true;