diff --git a/build-common/src/org/jetbrains/kotlin/incremental/LocalFileKotlinClass.kt b/build-common/src/org/jetbrains/kotlin/incremental/LocalFileKotlinClass.kt
index e94c8a3c101..1c7ecab6ca1 100644
--- a/build-common/src/org/jetbrains/kotlin/incremental/LocalFileKotlinClass.kt
+++ b/build-common/src/org/jetbrains/kotlin/incremental/LocalFileKotlinClass.kt
@@ -42,7 +42,8 @@ class LocalFileKotlinClass private constructor(
 
     val className: JvmClassName by lazy { JvmClassName.byClassId(classId) }
 
-    override fun getLocation(): String = file.absolutePath
+    override val location: String
+        get() = file.absolutePath
 
     public override fun getFileContents(): ByteArray = fileContents
 
diff --git a/compiler/frontend.java/src/org/jetbrains/kotlin/load/kotlin/VirtualFileKotlinClass.kt b/compiler/frontend.java/src/org/jetbrains/kotlin/load/kotlin/VirtualFileKotlinClass.kt
index 16fb8de8dfe..31db64c4ed5 100644
--- a/compiler/frontend.java/src/org/jetbrains/kotlin/load/kotlin/VirtualFileKotlinClass.kt
+++ b/compiler/frontend.java/src/org/jetbrains/kotlin/load/kotlin/VirtualFileKotlinClass.kt
@@ -33,7 +33,8 @@ class VirtualFileKotlinClass private constructor(
         innerClasses: FileBasedKotlinClass.InnerClassesInfo
 ) : FileBasedKotlinClass(className, classHeader, innerClasses) {
 
-    override fun getLocation() = file.path
+    override val location: String
+        get() = file.path
 
     override fun getFileContents(): ByteArray {
         try {
diff --git a/compiler/tests-common/org/jetbrains/kotlin/codegen/InlineTestUtil.kt b/compiler/tests-common/org/jetbrains/kotlin/codegen/InlineTestUtil.kt
index 07819129d59..ebac772e89a 100644
--- a/compiler/tests-common/org/jetbrains/kotlin/codegen/InlineTestUtil.kt
+++ b/compiler/tests-common/org/jetbrains/kotlin/codegen/InlineTestUtil.kt
@@ -182,7 +182,8 @@ object InlineTestUtil {
         val klass = FileBasedKotlinClass.create(file.asByteArray()) {
             className, classHeader, innerClasses ->
             object : FileBasedKotlinClass(className, classHeader, innerClasses) {
-                override fun getLocation(): String = throw UnsupportedOperationException()
+                override val location: String
+                    get() = throw UnsupportedOperationException()
                 override fun getFileContents(): ByteArray = throw UnsupportedOperationException()
                 override fun hashCode(): Int = throw UnsupportedOperationException()
                 override fun equals(other: Any?): Boolean = throw UnsupportedOperationException()
diff --git a/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/AbstractBinaryClassAnnotationAndConstantLoader.kt b/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/AbstractBinaryClassAnnotationAndConstantLoader.kt
index a0b39a3ea43..d57e177e2f9 100644
--- a/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/AbstractBinaryClassAnnotationAndConstantLoader.kt
+++ b/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/AbstractBinaryClassAnnotationAndConstantLoader.kt
@@ -146,14 +146,14 @@ abstract class AbstractBinaryClassAnnotationAndConstantLoader<A : Any, C : Any,
 
     override fun loadValueParameterAnnotations(
             container: ProtoContainer,
-            message: MessageLite,
+            callableProto: MessageLite,
             kind: AnnotatedCallableKind,
             parameterIndex: Int,
             proto: ProtoBuf.ValueParameter
     ): List<A> {
-        val methodSignature = getCallableSignature(message, container.nameResolver, container.typeTable, kind)
+        val methodSignature = getCallableSignature(callableProto, container.nameResolver, container.typeTable, kind)
         if (methodSignature != null) {
-            val index = parameterIndex + computeJvmParameterIndexShift(container, message)
+            val index = parameterIndex + computeJvmParameterIndexShift(container, callableProto)
             val paramSignature = MemberSignature.fromMethodSignatureAndParameterIndex(methodSignature, index)
             return findClassAndLoadMemberAnnotations(container, paramSignature)
         }
@@ -176,10 +176,10 @@ abstract class AbstractBinaryClassAnnotationAndConstantLoader<A : Any, C : Any,
 
     override fun loadExtensionReceiverParameterAnnotations(
             container: ProtoContainer,
-            message: MessageLite,
+            proto: MessageLite,
             kind: AnnotatedCallableKind
     ): List<A> {
-        val methodSignature = getCallableSignature(message, container.nameResolver, container.typeTable, kind)
+        val methodSignature = getCallableSignature(proto, container.nameResolver, container.typeTable, kind)
         if (methodSignature != null) {
             val paramSignature = MemberSignature.fromMethodSignatureAndParameterIndex(methodSignature, 0)
             return findClassAndLoadMemberAnnotations(container, paramSignature)
@@ -188,12 +188,12 @@ abstract class AbstractBinaryClassAnnotationAndConstantLoader<A : Any, C : Any,
         return emptyList()
     }
 
-    override fun loadTypeAnnotations(type: ProtoBuf.Type, nameResolver: NameResolver): List<A> {
-        return type.getExtension(JvmProtoBuf.typeAnnotation).map { loadTypeAnnotation(it, nameResolver) }
+    override fun loadTypeAnnotations(proto: ProtoBuf.Type, nameResolver: NameResolver): List<A> {
+        return proto.getExtension(JvmProtoBuf.typeAnnotation).map { loadTypeAnnotation(it, nameResolver) }
     }
 
-    override fun loadTypeParameterAnnotations(typeParameter: ProtoBuf.TypeParameter, nameResolver: NameResolver): List<A> {
-        return typeParameter.getExtension(JvmProtoBuf.typeParameterAnnotation).map { loadTypeAnnotation(it, nameResolver) }
+    override fun loadTypeParameterAnnotations(proto: ProtoBuf.TypeParameter, nameResolver: NameResolver): List<A> {
+        return proto.getExtension(JvmProtoBuf.typeParameterAnnotation).map { loadTypeAnnotation(it, nameResolver) }
     }
 
     override fun loadPropertyConstant(container: ProtoContainer, proto: ProtoBuf.Property, expectedType: KotlinType): C? {
diff --git a/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/KotlinJvmBinaryClass.kt b/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/KotlinJvmBinaryClass.kt
index bb0ac876152..d5841b7d3ed 100644
--- a/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/KotlinJvmBinaryClass.kt
+++ b/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/KotlinJvmBinaryClass.kt
@@ -14,74 +14,63 @@
  * limitations under the License.
  */
 
-package org.jetbrains.kotlin.load.kotlin;
+package org.jetbrains.kotlin.load.kotlin
 
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-import org.jetbrains.kotlin.descriptors.SourceElement;
-import org.jetbrains.kotlin.load.kotlin.header.KotlinClassHeader;
-import org.jetbrains.kotlin.name.ClassId;
-import org.jetbrains.kotlin.name.Name;
+import org.jetbrains.kotlin.descriptors.SourceElement
+import org.jetbrains.kotlin.load.kotlin.header.KotlinClassHeader
+import org.jetbrains.kotlin.name.ClassId
+import org.jetbrains.kotlin.name.Name
 
-public interface KotlinJvmBinaryClass {
-    @NotNull
-    ClassId getClassId();
+interface KotlinJvmBinaryClass {
+    val classId: ClassId
 
     /**
      * @return path to the class file (to be reported to the user upon error)
      */
-    @NotNull
-    String getLocation();
+    val location: String
 
-    void loadClassAnnotations(@NotNull AnnotationVisitor visitor);
+    fun loadClassAnnotations(visitor: AnnotationVisitor)
 
-    void visitMembers(@NotNull MemberVisitor visitor);
+    fun visitMembers(visitor: MemberVisitor)
 
-    @NotNull
-    KotlinClassHeader getClassHeader();
+    val classHeader: KotlinClassHeader
 
     interface MemberVisitor {
         // TODO: abstract signatures for methods and fields instead of ASM 'desc' strings?
 
-        @Nullable
-        MethodAnnotationVisitor visitMethod(@NotNull Name name, @NotNull String desc);
+        fun visitMethod(name: Name, desc: String): MethodAnnotationVisitor?
 
-        @Nullable
-        AnnotationVisitor visitField(@NotNull Name name, @NotNull String desc, @Nullable Object initializer);
+        fun visitField(name: Name, desc: String, initializer: Any?): AnnotationVisitor?
     }
 
     interface AnnotationVisitor {
-        @Nullable
-        AnnotationArgumentVisitor visitAnnotation(@NotNull ClassId classId, @NotNull SourceElement source);
+        fun visitAnnotation(classId: ClassId, source: SourceElement): AnnotationArgumentVisitor?
 
-        void visitEnd();
+        fun visitEnd()
     }
 
-    interface MethodAnnotationVisitor extends AnnotationVisitor {
-        @Nullable
-        AnnotationArgumentVisitor visitParameterAnnotation(int index, @NotNull ClassId classId, @NotNull SourceElement source);
+    interface MethodAnnotationVisitor : AnnotationVisitor {
+        fun visitParameterAnnotation(index: Int, classId: ClassId, source: SourceElement): AnnotationArgumentVisitor?
     }
 
     interface AnnotationArgumentVisitor {
         // TODO: class literals
-        void visit(@Nullable Name name, @Nullable Object value);
+        fun visit(name: Name?, value: Any?)
 
-        void visitEnum(@NotNull Name name, @NotNull ClassId enumClassId, @NotNull Name enumEntryName);
+        fun visitEnum(name: Name, enumClassId: ClassId, enumEntryName: Name)
 
-        @Nullable
-        AnnotationArgumentVisitor visitAnnotation(@NotNull Name name, @NotNull ClassId classId);
+        fun visitAnnotation(name: Name, classId: ClassId): AnnotationArgumentVisitor?
 
-        @Nullable
-        AnnotationArrayArgumentVisitor visitArray(@NotNull Name name);
+        fun visitArray(name: Name): AnnotationArrayArgumentVisitor?
 
-        void visitEnd();
+        fun visitEnd()
     }
 
     interface AnnotationArrayArgumentVisitor {
-        void visit(@Nullable Object value);
+        fun visit(value: Any?)
 
-        void visitEnum(@NotNull ClassId enumClassId, @NotNull Name enumEntryName);
+        fun visitEnum(enumClassId: ClassId, enumEntryName: Name)
 
-        void visitEnd();
+        fun visitEnd()
     }
 }
diff --git a/core/descriptors.runtime/src/org/jetbrains/kotlin/load/kotlin/reflect/ReflectKotlinClass.kt b/core/descriptors.runtime/src/org/jetbrains/kotlin/load/kotlin/reflect/ReflectKotlinClass.kt
index 38455677731..df71b7e6d3d 100644
--- a/core/descriptors.runtime/src/org/jetbrains/kotlin/load/kotlin/reflect/ReflectKotlinClass.kt
+++ b/core/descriptors.runtime/src/org/jetbrains/kotlin/load/kotlin/reflect/ReflectKotlinClass.kt
@@ -22,6 +22,7 @@ import org.jetbrains.kotlin.load.java.structure.reflect.isEnumClassOrSpecialized
 import org.jetbrains.kotlin.load.kotlin.KotlinJvmBinaryClass
 import org.jetbrains.kotlin.load.kotlin.header.KotlinClassHeader
 import org.jetbrains.kotlin.load.kotlin.header.ReadKotlinClassHeaderAnnotationVisitor
+import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.Name
 import java.lang.reflect.Constructor
 import java.lang.reflect.Field
@@ -41,7 +42,7 @@ private val TYPES_ELIGIBLE_FOR_SIMPLE_VISIT = setOf<Class<*>>(
 
 class ReflectKotlinClass private constructor(
         val klass: Class<*>,
-        private val classHeader: KotlinClassHeader
+        override val classHeader: KotlinClassHeader
 ) : KotlinJvmBinaryClass {
 
     companion object Factory {
@@ -53,11 +54,11 @@ class ReflectKotlinClass private constructor(
         }
     }
 
-    override fun getLocation() = klass.name.replace('.', '/') + ".class"
+    override val location: String
+        get() = klass.name.replace('.', '/') + ".class"
 
-    override fun getClassId() = klass.classId
-
-    override fun getClassHeader() = classHeader
+    override val classId: ClassId
+        get() = klass.classId
 
     override fun loadClassAnnotations(visitor: KotlinJvmBinaryClass.AnnotationVisitor) {
         ReflectClassStructure.loadClassAnnotations(klass, visitor)
diff --git a/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/AnnotationAndConstantLoader.kt b/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/AnnotationAndConstantLoader.kt
index c8c1f8ca94a..4d1dda930e2 100644
--- a/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/AnnotationAndConstantLoader.kt
+++ b/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/AnnotationAndConstantLoader.kt
@@ -14,70 +14,58 @@
  * limitations under the License.
  */
 
-package org.jetbrains.kotlin.serialization.deserialization;
+package org.jetbrains.kotlin.serialization.deserialization
 
-import com.google.protobuf.MessageLite;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-import org.jetbrains.kotlin.serialization.ProtoBuf;
-import org.jetbrains.kotlin.types.KotlinType;
-
-import java.util.List;
+import com.google.protobuf.MessageLite
+import org.jetbrains.kotlin.serialization.ProtoBuf
+import org.jetbrains.kotlin.types.KotlinType
 
 // The MessageLite instance everywhere should be Constructor, Function or Property
 // TODO: simplify this interface
-public interface AnnotationAndConstantLoader<A, C, T> {
-    @NotNull
-    List<A> loadClassAnnotations(
-            @NotNull ProtoBuf.Class classProto,
-            @NotNull NameResolver nameResolver
-    );
+interface AnnotationAndConstantLoader<A : Any, C : Any, T : Any> {
+    fun loadClassAnnotations(
+            classProto: ProtoBuf.Class,
+            nameResolver: NameResolver
+    ): List<A>
 
-    @NotNull
-    List<T> loadCallableAnnotations(
-            @NotNull ProtoContainer container,
-            @NotNull MessageLite message,
-            @NotNull AnnotatedCallableKind kind
-    );
+    fun loadCallableAnnotations(
+            container: ProtoContainer,
+            proto: MessageLite,
+            kind: AnnotatedCallableKind
+    ): List<T>
 
-    @NotNull
-    List<A> loadEnumEntryAnnotations(
-            @NotNull ProtoContainer container,
-            @NotNull ProtoBuf.EnumEntry proto
-    );
+    fun loadEnumEntryAnnotations(
+            container: ProtoContainer,
+            proto: ProtoBuf.EnumEntry
+    ): List<A>
 
-    @NotNull
-    List<A> loadValueParameterAnnotations(
-            @NotNull ProtoContainer container,
-            @NotNull MessageLite message,
-            @NotNull AnnotatedCallableKind kind,
-            int parameterIndex,
-            @NotNull ProtoBuf.ValueParameter proto
-    );
+    fun loadValueParameterAnnotations(
+            container: ProtoContainer,
+            callableProto: MessageLite,
+            kind: AnnotatedCallableKind,
+            parameterIndex: Int,
+            proto: ProtoBuf.ValueParameter
+    ): List<A>
 
-    @NotNull
-    List<A> loadExtensionReceiverParameterAnnotations(
-            @NotNull ProtoContainer container,
-            @NotNull MessageLite message,
-            @NotNull AnnotatedCallableKind kind
-    );
+    fun loadExtensionReceiverParameterAnnotations(
+            container: ProtoContainer,
+            proto: MessageLite,
+            kind: AnnotatedCallableKind
+    ): List<A>
 
-    @NotNull
-    List<A> loadTypeAnnotations(
-            @NotNull ProtoBuf.Type type,
-            @NotNull NameResolver nameResolver
-    );
+    fun loadTypeAnnotations(
+            proto: ProtoBuf.Type,
+            nameResolver: NameResolver
+    ): List<A>
 
-    @NotNull
-    List<A> loadTypeParameterAnnotations(
-            @NotNull ProtoBuf.TypeParameter typeParameter,
-            @NotNull NameResolver nameResolver
-    );
+    fun loadTypeParameterAnnotations(
+            proto: ProtoBuf.TypeParameter,
+            nameResolver: NameResolver
+    ): List<A>
 
-    @Nullable
-    C loadPropertyConstant(
-            @NotNull ProtoContainer container,
-            @NotNull ProtoBuf.Property proto,
-            @NotNull KotlinType expectedType
-    );
+    fun loadPropertyConstant(
+            container: ProtoContainer,
+            proto: ProtoBuf.Property,
+            expectedType: KotlinType
+    ): C?
 }
diff --git a/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/AnnotationAndConstantLoaderImpl.kt b/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/AnnotationAndConstantLoaderImpl.kt
index a132a26f36f..410f1fa441a 100644
--- a/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/AnnotationAndConstantLoaderImpl.kt
+++ b/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/AnnotationAndConstantLoaderImpl.kt
@@ -64,7 +64,7 @@ class AnnotationAndConstantLoaderImpl(
 
     override fun loadValueParameterAnnotations(
             container: ProtoContainer,
-            message: MessageLite,
+            callableProto: MessageLite,
             kind: AnnotatedCallableKind,
             parameterIndex: Int,
             proto: ProtoBuf.ValueParameter
@@ -75,7 +75,7 @@ class AnnotationAndConstantLoaderImpl(
 
     override fun loadExtensionReceiverParameterAnnotations(
             container: ProtoContainer,
-            message: MessageLite,
+            proto: MessageLite,
             kind: AnnotatedCallableKind
     ): List<AnnotationDescriptor> = emptyList()
 
diff --git a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/common/AnnotationLoaderForStubBuilderImpl.kt b/idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/common/AnnotationLoaderForStubBuilderImpl.kt
index bdfc015941b..a62d52ce181 100644
--- a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/common/AnnotationLoaderForStubBuilderImpl.kt
+++ b/idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/common/AnnotationLoaderForStubBuilderImpl.kt
@@ -57,7 +57,7 @@ class AnnotationLoaderForStubBuilderImpl(
 
     override fun loadValueParameterAnnotations(
             container: ProtoContainer,
-            message: MessageLite,
+            callableProto: MessageLite,
             kind: AnnotatedCallableKind,
             parameterIndex: Int,
             proto: ProtoBuf.ValueParameter
@@ -66,7 +66,7 @@ class AnnotationLoaderForStubBuilderImpl(
 
     override fun loadExtensionReceiverParameterAnnotations(
             container: ProtoContainer,
-            message: MessageLite,
+            proto: MessageLite,
             kind: AnnotatedCallableKind
     ): List<ClassId> = emptyList()