Check for repeated annotations in type alias expansion.

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

@@ -22,6 +22,7 @@ import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
 import org.jetbrains.kotlin.diagnostics.DiagnosticFactory0
 import org.jetbrains.kotlin.diagnostics.Errors
@@ -32,6 +33,7 @@ import org.jetbrains.kotlin.psi.psiUtil.visibilityModifier
 import org.jetbrains.kotlin.resolve.BindingContext.*
 import org.jetbrains.kotlin.resolve.DescriptorUtils.classCanHaveAbstractMembers
 import org.jetbrains.kotlin.resolve.DescriptorUtils.classCanHaveOpenMembers
+import org.jetbrains.kotlin.resolve.source.KotlinSourceElement
 import org.jetbrains.kotlin.types.*
 import org.jetbrains.kotlin.types.checker.KotlinTypeChecker
 import org.jetbrains.kotlin.types.typeUtil.*
@@ -214,6 +216,11 @@ class DeclarationsChecker(
                 trace.report(UPPER_BOUND_VIOLATED_IN_TYPEALIAS_EXPANSION.on(typeReference, bound, argument, typeParameter))
             }
         }
+
+        override fun repeatedAnnotation(annotation: AnnotationDescriptor) {
+            val annotationEntry = (annotation.source as? KotlinSourceElement)?.psi as? KtAnnotationEntry ?: return
+            trace.report(REPEATED_ANNOTATION.on(annotationEntry))
+        }
     }
 
     private fun checkTypeAliasExpansion(declaration: KtTypeAlias, typeAliasDescriptor: TypeAliasDescriptor) {

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

@@ -18,6 +18,7 @@ package org.jetbrains.kotlin.resolve
 
 import org.jetbrains.kotlin.descriptors.TypeAliasDescriptor
 import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
+import org.jetbrains.kotlin.descriptors.annotations.AnnotationUseSiteTarget
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationsImpl
 import org.jetbrains.kotlin.descriptors.annotations.CompositeAnnotations
@@ -51,8 +52,7 @@ class TypeAliasExpander(
             "Type alias expansion: result for ${typeAliasExpansion.descriptor} is ${expandedProjection.projectionKind}, should be invariant"
         }
 
-        val expandedTypeWithExtraAnnotations = expandedType.replace(
+        val expandedTypeWithExtraAnnotations = combineAnnotations(expandedType, annotations)
-                newAnnotations = CompositeAnnotations(listOf(annotations, expandedType.annotations)))
 
         return if (withAbbreviatedType)
             expandedTypeWithExtraAnnotations.withAbbreviation(typeAliasExpansion.createAbbreviation(originalProjection, annotations))
@@ -60,6 +60,18 @@ class TypeAliasExpander(
             expandedTypeWithExtraAnnotations
     }
 
+    private fun combineAnnotations(type: SimpleType, annotations: Annotations): SimpleType {
+        val existingAnnotationTypes = type.annotations.getAllAnnotations().mapTo(hashSetOf<KotlinType>()) { it.annotation.type }
+
+        for (annotation in annotations) {
+            if (annotation.type in existingAnnotationTypes) {
+                reportStrategy.repeatedAnnotation(annotation)
+            }
+        }
+
+        return type.replace(newAnnotations = CompositeAnnotations(listOf(annotations, type.annotations)))
+    }
+
     private fun TypeAliasExpansion.createAbbreviation(originalProjection: TypeProjection, annotations: Annotations) =
             KotlinTypeFactory.simpleType(
                     annotations,

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

@@ -18,6 +18,7 @@ package org.jetbrains.kotlin.resolve
 
 import org.jetbrains.kotlin.descriptors.TypeAliasDescriptor
 import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
+import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
 import org.jetbrains.kotlin.types.KotlinType
 
 interface TypeAliasExpansionReportStrategy {
@@ -25,11 +26,13 @@ interface TypeAliasExpansionReportStrategy {
     fun conflictingProjection(typeAlias: TypeAliasDescriptor, typeParameter: TypeParameterDescriptor?, substitutedArgument: KotlinType)
     fun recursiveTypeAlias(typeAlias: TypeAliasDescriptor)
     fun boundsViolationInSubstitution(bound: KotlinType, unsubstitutedArgument: KotlinType, argument: KotlinType, typeParameter: TypeParameterDescriptor)
+    fun repeatedAnnotation(annotation: AnnotationDescriptor)
 
     object DO_NOTHING : TypeAliasExpansionReportStrategy {
         override fun wrongNumberOfTypeArguments(typeAlias: TypeAliasDescriptor, numberOfParameters: Int) {}
         override fun conflictingProjection(typeAlias: TypeAliasDescriptor, typeParameter: TypeParameterDescriptor?, substitutedArgument: KotlinType) {}
         override fun recursiveTypeAlias(typeAlias: TypeAliasDescriptor) {}
         override fun boundsViolationInSubstitution(bound: KotlinType, unsubstitutedArgument: KotlinType, argument: KotlinType, typeParameter: TypeParameterDescriptor) {}
+        override fun repeatedAnnotation(annotation: AnnotationDescriptor) {}
     }
 }

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

@@ -21,6 +21,7 @@ import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.context.TypeLazinessToken
 import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
 import org.jetbrains.kotlin.descriptors.impl.VariableDescriptorImpl
 import org.jetbrains.kotlin.diagnostics.Errors
@@ -42,6 +43,7 @@ import org.jetbrains.kotlin.resolve.scopes.LexicalScope
 import org.jetbrains.kotlin.resolve.scopes.LexicalScopeKind
 import org.jetbrains.kotlin.resolve.scopes.MemberScope
 import org.jetbrains.kotlin.resolve.scopes.utils.findFirstFromMeAndParent
+import org.jetbrains.kotlin.resolve.source.KotlinSourceElement
 import org.jetbrains.kotlin.resolve.source.toSourceElement
 import org.jetbrains.kotlin.storage.LockBasedStorageManager
 import org.jetbrains.kotlin.storage.StorageManager
@@ -519,7 +521,7 @@ class TypeResolver(
 
         override fun conflictingProjection(typeAlias: TypeAliasDescriptor, typeParameter: TypeParameterDescriptor?, substitutedArgument: KotlinType) {
             val argumentElement = typeParameter?.let { mappedArguments[it] }
-            if (argumentElement != null && typeParameter != null) {
+            if (argumentElement != null) {
                 trace.report(CONFLICTING_PROJECTION.on(argumentElement, typeParameter))
             }
             else if (type != null) {
@@ -544,10 +546,13 @@ class TypeResolver(
                 trace.report(UPPER_BOUND_VIOLATED_IN_TYPEALIAS_EXPANSION.on(type, bound, argument, typeParameter))
             }
         }
+
+        override fun repeatedAnnotation(annotation: AnnotationDescriptor) {
+            val annotationEntry = (annotation.source as? KotlinSourceElement)?.psi as? KtAnnotationEntry ?: return
+            trace.report(REPEATED_ANNOTATION.on(annotationEntry))
+        }
     }
 
-
-
     private fun createErrorTypeForTypeConstructor(
             c: TypeResolutionContext,
             arguments: List<KtTypeProjection>,

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/CandidateResolver.kt

@@ -20,6 +20,7 @@ import com.google.common.collect.Lists
 import com.google.common.collect.Sets
 import org.jetbrains.kotlin.builtins.ReflectionTypes
 import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
 import org.jetbrains.kotlin.descriptors.impl.TypeAliasConstructorDescriptor
 import org.jetbrains.kotlin.diagnostics.Errors
 import org.jetbrains.kotlin.diagnostics.Errors.*
@@ -597,15 +598,19 @@ class CandidateResolver(
         private val argumentsMapping = typeAlias.declaredTypeParameters.zip(ktTypeArguments).toMap()
 
         override fun wrongNumberOfTypeArguments(typeAlias: TypeAliasDescriptor, numberOfParameters: Int) {
-            // TODO
+            // can't happen in single-step expansion
         }
 
         override fun conflictingProjection(typeAlias: TypeAliasDescriptor, typeParameter: TypeParameterDescriptor?, substitutedArgument: KotlinType) {
-            // TODO
+            // can't happen in single-step expansion
         }
 
         override fun recursiveTypeAlias(typeAlias: TypeAliasDescriptor) {
-            // can't happen in non-error type
+            // can't happen in single-step expansion
+        }
+
+        override fun repeatedAnnotation(annotation: AnnotationDescriptor) {
+            // can't happen in single-step expansion
         }
 
         override fun boundsViolationInSubstitution(bound: KotlinType, unsubstitutedArgument: KotlinType, argument: KotlinType, typeParameter: TypeParameterDescriptor) {

compiler/testData/diagnostics/tests/typealias/typeAliasExpansionRepeatedAnnotations.kt

@@ -0,0 +1,16 @@
+@Target(AnnotationTarget.TYPE)
+annotation class A
+
+typealias AInt = @A Int
+typealias AI = AInt
+
+typealias Test1 = <!REPEATED_ANNOTATION!>@A<!> AInt
+typealias Test2 = <!REPEATED_ANNOTATION!>@A<!> AI
+typealias Test3 = List<<!REPEATED_ANNOTATION!>@A<!> AInt>
+typealias Test4 = List<<!REPEATED_ANNOTATION!>@A<!> AI>
+
+val testProperty1: <!REPEATED_ANNOTATION!>@A<!> AInt = 0
+val testProperty2: <!REPEATED_ANNOTATION!>@A<!> AI = 0
+
+fun testFunction1(x: <!REPEATED_ANNOTATION!>@A<!> AInt): <!REPEATED_ANNOTATION!>@A<!> AInt = x
+fun testFunction2(x: <!REPEATED_ANNOTATION!>@A<!> AI): <!REPEATED_ANNOTATION!>@A<!> AI = x

compiler/testData/diagnostics/tests/typealias/typeAliasExpansionRepeatedAnnotations.txt

@@ -0,0 +1,19 @@
+package
+
+public val testProperty1: @A AInt /* = @A @A kotlin.Int */ = 0
+public val testProperty2: @A AI /* = @A @A kotlin.Int */ = 0
+public fun testFunction1(/*0*/ x: @A AInt /* = @A @A kotlin.Int */): @A AInt /* = @A @A kotlin.Int */
+public fun testFunction2(/*0*/ x: @A AI /* = @A @A kotlin.Int */): @A AI /* = @A @A kotlin.Int */
+
+@kotlin.annotation.Target(allowedTargets = {AnnotationTarget.TYPE}) public final annotation class A : kotlin.Annotation {
+    public constructor A()
+    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 AI = AInt
+public typealias AInt = @A kotlin.Int
+public typealias Test1 = @A AInt
+public typealias Test2 = @A AI
+public typealias Test3 = kotlin.collections.List<@A AInt>
+public typealias Test4 = kotlin.collections.List<@A AI>

compiler/testData/diagnostics/tests/typealias/typealiasRhsAnnotations.kt

@@ -14,8 +14,3 @@ fun test2(a: Alias3) = a
 
 typealias LA1 = List<@Ann2 Alias1>
 fun test3(la1: LA1) = la1
-
-// see KT-14318
-typealias AliasRepeated = @Ann1 Alias1
-fun test4(a: AliasRepeated) = a
-fun test4a(a: @Ann1 Alias1) = a

compiler/testData/diagnostics/tests/typealias/typealiasRhsAnnotations.txt

@@ -3,8 +3,6 @@ package
 public fun test1(/*0*/ a: Alias2 /* = @Ann2 @Ann1 kotlin.String */): Alias2 /* = @Ann2 @Ann1 kotlin.String */
 public fun test2(/*0*/ a: Alias3 /* = @kotlin.ExtensionFunctionType @Ann1 kotlin.String */): Alias3 /* = @kotlin.ExtensionFunctionType @Ann1 kotlin.String */
 public fun test3(/*0*/ la1: LA1 /* = kotlin.collections.List<@Ann2 Alias1 /* = @Ann2 @Ann1 kotlin.String */> */): LA1 /* = kotlin.collections.List<@Ann2 Alias1 /* = @Ann2 @Ann1 kotlin.String */> */
-public fun test4(/*0*/ a: AliasRepeated /* = @Ann1 @Ann1 kotlin.String */): AliasRepeated /* = @Ann1 @Ann1 kotlin.String */
-public fun test4a(/*0*/ a: @Ann1 Alias1 /* = @Ann1 @Ann1 kotlin.String */): @Ann1 Alias1 /* = @Ann1 @Ann1 kotlin.String */
 
 @kotlin.annotation.Target(allowedTargets = {AnnotationTarget.TYPE}) public final annotation class Ann1 : kotlin.Annotation {
     public constructor Ann1()
@@ -22,5 +20,4 @@ public fun test4a(/*0*/ a: @Ann1 Alias1 /* = @Ann1 @Ann1 kotlin.String */): @Ann
 public typealias Alias1 = @Ann1 kotlin.String
 public typealias Alias2 = @Ann2 Alias1
 public typealias Alias3 = @kotlin.ExtensionFunctionType Alias1
-public typealias AliasRepeated = @Ann1 Alias1
 public typealias LA1 = kotlin.collections.List<@Ann2 Alias1>

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

@@ -20868,6 +20868,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("typeAliasExpansionRepeatedAnnotations.kt")
+            public void testTypeAliasExpansionRepeatedAnnotations() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/typealias/typeAliasExpansionRepeatedAnnotations.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("typeAliasInAnonymousObjectType.kt")
             public void testTypeAliasInAnonymousObjectType() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/typealias/typeAliasInAnonymousObjectType.kt");