Report deprecation on usage of type alias expanded to a deprecated class

 #KT-15243 Fixed

Author: dnpetrov

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

@@ -37,6 +37,8 @@ import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
 import org.jetbrains.kotlin.serialization.deserialization.descriptors.DeserializedClassDescriptor
 import org.jetbrains.kotlin.serialization.deserialization.descriptors.DeserializedMemberDescriptor
 import org.jetbrains.kotlin.serialization.deserialization.descriptors.SinceKotlinInfo
+import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.TypeUtils
 import org.jetbrains.kotlin.utils.SmartList
 
 private val JAVA_DEPRECATED = FqName("java.lang.Deprecated")
@@ -143,6 +145,16 @@ fun DeclarationDescriptor.getDeprecations(languageVersionSettings: LanguageVersi
     return emptyList()
 }
 
+private fun KotlinType.deprecationsByConstituentTypes(languageVersionSettings: LanguageVersionSettings): List<Deprecation> =
+        SmartList<Deprecation>().also { deprecations ->
+            TypeUtils.contains(this) { type ->
+                type.constructor.declarationDescriptor?.run {
+                    deprecations.addAll(getDeprecations(languageVersionSettings))
+                }
+                false
+            }
+        }
+
 private fun deprecationByOverridden(root: CallableMemberDescriptor, languageVersionSettings: LanguageVersionSettings): Deprecation? {
     val visited = HashSet<CallableMemberDescriptor>()
     val deprecations = LinkedHashSet<Deprecation>()
@@ -177,13 +189,6 @@ private fun deprecationByOverridden(root: CallableMemberDescriptor, languageVers
 }
 
 private fun DeclarationDescriptor.getOwnDeprecations(languageVersionSettings: LanguageVersionSettings): List<Deprecation> {
-    if (this is TypeAliasConstructorDescriptor) {
-        // Constructor of type alias has no annotations by itself, all its annotations come from the aliased constructor
-        // and from the typealias declaration
-        return underlyingConstructorDescriptor.getOwnDeprecations(languageVersionSettings) +
-               typeAliasDescriptor.getOwnDeprecations(languageVersionSettings)
-    }
-
     // The problem is that declaration `mod` in built-ins has @Deprecated annotation but actually it was deprecated only in version 1.1
     if (this is FunctionDescriptor && this.isOperatorMod() && this.hasSubpackageOfKotlin()) {
         if (!shouldWarnAboutDeprecatedModFromBuiltIns(languageVersionSettings)) {
@@ -227,6 +232,12 @@ private fun DeclarationDescriptor.getOwnDeprecations(languageVersionSettings: La
     addUseSiteTargetedDeprecationIfPresent(this, AnnotationUseSiteTarget.getAssociatedUseSiteTarget(this))
 
     when (this) {
+        is TypeAliasDescriptor -> {
+            result.addAll(expandedType.deprecationsByConstituentTypes(languageVersionSettings))
+        }
+        is TypeAliasConstructorDescriptor -> {
+            result.addAll(typeAliasDescriptor.getOwnDeprecations(languageVersionSettings))
+        }
         is ConstructorDescriptor -> {
             addDeprecationIfPresent(containingDeclaration)
         }

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

@@ -8,7 +8,10 @@ open class WithDeprecatedCtor(val x: Int) {
 
 typealias DeprecatedClassAlias = <!DEPRECATION!>DeprecatedClass<!>
 typealias WithDeprecatedCtorAlias = WithDeprecatedCtor
+typealias ArrayListOfDeprecatedClass = ArrayList<<!DEPRECATION!>DeprecatedClass<!>>
 
 class Test1 : <!DEPRECATION!>DeprecatedClassAlias<!>()
 
-class Test2 : <!DEPRECATION!>WithDeprecatedCtorAlias<!>()
+class Test2 : <!DEPRECATION!>WithDeprecatedCtorAlias<!>()
+
+val test3 = <!DEPRECATION!>ArrayListOfDeprecatedClass<!>()

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

@@ -1,5 +1,7 @@
 package
 
+public val test3: ArrayListOfDeprecatedClass /* = java.util.ArrayList<DeprecatedClass> */
+
 @kotlin.Deprecated(message = "Deprecated class") public open class DeprecatedClass {
     public constructor DeprecatedClass()
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
@@ -30,5 +32,6 @@ public open class WithDeprecatedCtor {
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }
+public typealias ArrayListOfDeprecatedClass = kotlin.collections.ArrayList<DeprecatedClass>
 public typealias DeprecatedClassAlias = DeprecatedClass
 public typealias WithDeprecatedCtorAlias = WithDeprecatedCtor

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

@@ -0,0 +1,10 @@
+@Deprecated("")
+class Foo
+
+typealias Test1 = <!DEPRECATION!>Foo<!>
+typealias Test2 = List<<!DEPRECATION!>Foo<!>>
+typealias Test3 = List<<!DEPRECATION!>Test2<!>>
+
+fun use1(b: <!DEPRECATION!>Test1<!>) = b
+fun use2(b: <!DEPRECATION!>Test2<!>) = b
+fun use3(b: <!DEPRECATION!>Test3<!>) = b

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

@@ -0,0 +1,15 @@
+package
+
+public fun use1(/*0*/ b: Test1 /* = Foo */): Test1 /* = Foo */
+public fun use2(/*0*/ b: Test2 /* = kotlin.collections.List<Foo> */): Test2 /* = kotlin.collections.List<Foo> */
+public fun use3(/*0*/ b: Test3 /* = kotlin.collections.List<Test2 /* = kotlin.collections.List<Foo> */> */): Test3 /* = kotlin.collections.List<Test2 /* = kotlin.collections.List<Foo> */> */
+
+@kotlin.Deprecated(message = "") public final class Foo {
+    public constructor Foo()
+    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 typealias Test1 = Foo
+public typealias Test2 = kotlin.collections.List<Foo>
+public typealias Test3 = kotlin.collections.List<Test2>

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

@@ -6607,6 +6607,12 @@ public void testTypealiasConstructor() throws Exception {
                 doTest(fileName);
             }
 
+            @TestMetadata("typealiasForDeprecatedClass.kt")
+            public void testTypealiasForDeprecatedClass() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/deprecated/typealiasForDeprecatedClass.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("typealiasUsage.kt")
             public void testTypealiasUsage() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/deprecated/typealiasUsage.kt");