Report deprecation on typealias companion object for deprecated alias

compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ClassifierUsageChecker.kt

@@ -21,6 +21,7 @@ import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.ClassifierDescriptor
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptorWithSource
+import org.jetbrains.kotlin.descriptors.TypeAliasDescriptor
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.KtNameReferenceExpression
 import org.jetbrains.kotlin.psi.KtReferenceExpression
@@ -28,6 +29,7 @@ import org.jetbrains.kotlin.psi.KtTreeVisitorVoid
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.BindingTrace
 import org.jetbrains.kotlin.resolve.DescriptorUtils
+import org.jetbrains.kotlin.utils.addToStdlib.safeAs
 
 interface ClassifierUsageChecker {
     fun check(
@@ -58,9 +60,12 @@ interface ClassifierUsageChecker {
 
                     runCheckersWithTarget(target, expression)
 
-                    if (isReferenceToCompanionViaOuterClass(expression, target)) {
+                    getReferenceToCompanionViaClassifier(expression, target)?.let { referenceClassifier ->
                         val outerClass = target.containingDeclaration as ClassDescriptor
                         runCheckersWithTarget(outerClass, expression)
+                        if (referenceClassifier is TypeAliasDescriptor) {
+                            runCheckersWithTarget(referenceClassifier, expression)
+                        }
                     }
                 }
 
@@ -84,12 +89,9 @@ interface ClassifierUsageChecker {
                     return targets.filterIsInstance<ClassifierDescriptor>().singleOrNull()
                 }
 
-                /**
-                 * @return true iff [expression] references the companion of a class Foo via the name Foo, e.g. in `Foo.bar()`
-                 */
-                private fun isReferenceToCompanionViaOuterClass(expression: KtReferenceExpression, target: ClassifierDescriptor?): Boolean {
-                    return DescriptorUtils.isCompanionObject(target) &&
-                           trace.get(BindingContext.SHORT_REFERENCE_TO_COMPANION_OBJECT, expression) != null
+                private fun getReferenceToCompanionViaClassifier(expression: KtReferenceExpression, target: ClassifierDescriptor): ClassifierDescriptor? {
+                    if (!DescriptorUtils.isCompanionObject(target)) return null
+                    return trace.get(BindingContext.SHORT_REFERENCE_TO_COMPANION_OBJECT, expression)
                 }
             }
 

compiler/frontend/src/org/jetbrains/kotlin/resolve/deprecationUtil.kt

@@ -24,6 +24,7 @@ import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationUseSiteTarget
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
+import org.jetbrains.kotlin.descriptors.impl.DescriptorDerivedFromTypeAlias
 import org.jetbrains.kotlin.descriptors.impl.TypeAliasConstructorDescriptor
 import org.jetbrains.kotlin.diagnostics.Diagnostic
 import org.jetbrains.kotlin.diagnostics.Errors
@@ -253,7 +254,7 @@ private fun DeclarationDescriptor.getOwnDeprecations(languageVersionSettings: La
         is TypeAliasDescriptor -> {
             expandedType.deprecationsByConstituentTypes(languageVersionSettings).mapTo(result) { it.wrapInTypeAliasExpansion(this) }
         }
-        is TypeAliasConstructorDescriptor -> {
+        is DescriptorDerivedFromTypeAlias -> {
             result.addAll(typeAliasDescriptor.getOwnDeprecations(languageVersionSettings))
         }
         is ConstructorDescriptor -> {

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/util/FakeCallableDescriptorForTypeAliasObject.kt

@@ -17,9 +17,12 @@
 package org.jetbrains.kotlin.resolve.calls.util
 
 import org.jetbrains.kotlin.descriptors.TypeAliasDescriptor
+import org.jetbrains.kotlin.descriptors.impl.DescriptorDerivedFromTypeAlias
 
-class FakeCallableDescriptorForTypeAliasObject(val typeAliasDescriptor: TypeAliasDescriptor) :
-        FakeCallableDescriptorForObject(typeAliasDescriptor.classDescriptor!!) {
+class FakeCallableDescriptorForTypeAliasObject(override val typeAliasDescriptor: TypeAliasDescriptor) :
+        FakeCallableDescriptorForObject(typeAliasDescriptor.classDescriptor!!),
+        DescriptorDerivedFromTypeAlias
+{
     override fun getReferencedDescriptor() =
             typeAliasDescriptor
 

compiler/testData/diagnostics/tests/deprecated/typealiasCompanionObject.kt

@@ -0,0 +1,12 @@
+class Relevant {
+    companion object {
+        val value = ""
+    }
+}
+
+@Deprecated("Use Relevant")
+typealias Obsolete = Relevant
+
+fun test1() = <!DEPRECATION!>Obsolete<!>
+fun test2() = <!DEPRECATION!>Obsolete<!>.value
+fun test3() = <!DEPRECATION!>Obsolete<!>.toString()

compiler/testData/diagnostics/tests/deprecated/typealiasCompanionObject.txt

@@ -0,0 +1,21 @@
+package
+
+public fun test1(): Relevant.Companion
+public fun test2(): kotlin.String
+public fun test3(): kotlin.String
+
+public final class Relevant {
+    public constructor Relevant()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    public companion object Companion {
+        private constructor Companion()
+        public final val value: kotlin.String = ""
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+}
+@kotlin.Deprecated(message = "Use Relevant") public typealias Obsolete = Relevant

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -6619,6 +6619,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("typealiasCompanionObject.kt")
+            public void testTypealiasCompanionObject() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/deprecated/typealiasCompanionObject.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("typealiasConstructor.kt")
             public void testTypealiasConstructor() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/deprecated/typealiasConstructor.kt");

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/DescriptorDerivedFromTypeAlias.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2010-2017 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 org.jetbrains.kotlin.descriptors.impl
+
+import org.jetbrains.kotlin.descriptors.TypeAliasDescriptor
+
+interface DescriptorDerivedFromTypeAlias {
+    val typeAliasDescriptor: TypeAliasDescriptor
+}

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/TypeAliasConstructorDescriptor.kt

@@ -24,9 +24,8 @@ import org.jetbrains.kotlin.storage.StorageManager
 import org.jetbrains.kotlin.storage.getValue
 import org.jetbrains.kotlin.types.*
 
-interface TypeAliasConstructorDescriptor : ConstructorDescriptor {
+interface TypeAliasConstructorDescriptor : ConstructorDescriptor, DescriptorDerivedFromTypeAlias {
     val underlyingConstructorDescriptor: ClassConstructorDescriptor
-    val typeAliasDescriptor: TypeAliasDescriptor
 
     override fun getContainingDeclaration(): TypeAliasDescriptor