Fix checking repeatablilty of use-site target annotations. KT-26638 fixed

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/Errors.java

@@ -213,6 +213,7 @@ public interface Errors {
     DiagnosticFactory2<KtAnnotationEntry, String, String> WRONG_ANNOTATION_TARGET_WITH_USE_SITE_TARGET = DiagnosticFactory2.create(ERROR);
     DiagnosticFactory1<KtAnnotationEntry, String> WRONG_ANNOTATION_TARGET_WITH_USE_SITE_TARGET_ON_TYPE = DiagnosticFactory1.create(WARNING);
     DiagnosticFactory0<KtAnnotationEntry> REPEATED_ANNOTATION = DiagnosticFactory0.create(ERROR);
+    DiagnosticFactory0<KtAnnotationEntry> REPEATED_ANNOTATION_WARNING = DiagnosticFactory0.create(WARNING);
     DiagnosticFactory0<KtAnnotationEntry> NON_SOURCE_ANNOTATION_ON_INLINED_LAMBDA_EXPRESSION = DiagnosticFactory0.create(ERROR);
 
     // Annotations

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java

@@ -128,6 +128,7 @@ public class DefaultErrorMessages {
         MAP.put(WRONG_ANNOTATION_TARGET_WITH_USE_SITE_TARGET_ON_TYPE,
                 "Use of this annotation with target ''type'' and use site target ''@{0}'' is deprecated", TO_STRING);
         MAP.put(REPEATED_ANNOTATION, "This annotation is not repeatable");
+        MAP.put(REPEATED_ANNOTATION_WARNING, "This annotation is not repeatable");
         MAP.put(NON_SOURCE_ANNOTATION_ON_INLINED_LAMBDA_EXPRESSION, "The lambda expression here is an inlined argument so this annotation cannot be stored anywhere");
 
         MAP.put(INAPPLICABLE_TARGET_ON_PROPERTY, "''@{0}:'' annotations could be applied only to property declarations", TO_STRING);

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

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.resolve
 
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
@@ -16,6 +17,7 @@ import org.jetbrains.kotlin.descriptors.annotations.KotlinRetention
 import org.jetbrains.kotlin.descriptors.annotations.KotlinTarget
 import org.jetbrains.kotlin.descriptors.annotations.KotlinTarget.*
 import org.jetbrains.kotlin.diagnostics.Errors
+import org.jetbrains.kotlin.diagnostics.reportDiagnosticOnce
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.getAnnotationEntries
@@ -36,6 +38,9 @@ class AnnotationChecker(
     fun check(annotated: KtAnnotated, trace: BindingTrace, descriptor: DeclarationDescriptor? = null) {
         val actualTargets = getActualTargetList(annotated, descriptor, trace.bindingContext)
         checkEntries(annotated.annotationEntries, actualTargets, trace, annotated)
+        if (annotated is KtProperty) {
+            checkPropertyUseSiteTargetAnnotations(annotated, trace)
+        }
         if (annotated is KtCallableDeclaration) {
             annotated.typeReference?.let { check(it, trace) }
             annotated.receiverTypeReference?.let { check(it, trace) }
@@ -72,6 +77,33 @@ class AnnotationChecker(
         }
     }
 
+    private fun checkPropertyUseSiteTargetAnnotations(property: KtProperty, trace: BindingTrace) {
+        fun List<KtAnnotationEntry>?.getDescriptors() = this?.mapNotNull { trace.get(BindingContext.ANNOTATION, it)?.annotationClass } ?: listOf()
+
+        val reportError = languageVersionSettings.supportsFeature(LanguageFeature.ProhibitRepeatedUseSiteTargetAnnotations)
+
+        val propertyAnnotations = mapOf(
+            AnnotationUseSiteTarget.PROPERTY_GETTER to property.getter?.annotationEntries.getDescriptors(),
+            AnnotationUseSiteTarget.PROPERTY_SETTER to property.setter?.annotationEntries.getDescriptors(),
+            AnnotationUseSiteTarget.SETTER_PARAMETER to property.setter?.parameter?.annotationEntries.getDescriptors()
+        )
+
+        for (entry in property.annotationEntries) {
+            val descriptor = trace.get(BindingContext.ANNOTATION, entry) ?: continue
+            val classDescriptor = descriptor.annotationClass ?: continue
+
+            val useSiteTarget = entry.useSiteTarget?.getAnnotationUseSiteTarget() ?: property.getDefaultUseSiteTarget(descriptor)
+            val existingAnnotations = propertyAnnotations.get(useSiteTarget) ?: continue
+            if (classDescriptor in existingAnnotations && !classDescriptor.isRepeatableAnnotation()) {
+                if (reportError) {
+                    trace.reportDiagnosticOnce(Errors.REPEATED_ANNOTATION.on(entry))
+                } else {
+                    trace.report(Errors.REPEATED_ANNOTATION_WARNING.on(entry))
+                }
+            }
+        }
+    }
+
     private fun KtAnnotated?.getImplicitUseSiteTargetList(): List<AnnotationUseSiteTarget> = when (this) {
         is KtParameter ->
             if (ownerFunction is KtPrimaryConstructor) UseSiteTargetsList.T_CONSTRUCTOR_PARAMETER else emptyList()

compiler/testData/diagnostics/tests/annotations/withUseSiteTarget/kt26638.kt

@@ -1,21 +1,22 @@
 // !DIAGNOSTICS: -UNUSED_PARAMETER
+// !LANGUAGE: -ProhibitRepeatedUseSiteTargetAnnotations
 
 // Ann is not repeatable
 annotation class Ann(val x: Int)
 
-@get:Ann(10)
+<!REPEATED_ANNOTATION_WARNING!>@get:Ann(10)<!>
 val a: String
     @Ann(20) get() = "foo"
 
-@set:Ann(10)
+<!REPEATED_ANNOTATION_WARNING!>@set:Ann(10)<!>
 var b: String = ""
     @Ann(20) set(value) { field = value }
 
-@setparam:Ann(10)
+<!REPEATED_ANNOTATION_WARNING!>@setparam:Ann(10)<!>
 var c = " "
     set(@Ann(20) x) {}
 
-@get:Ann(10)
+<!REPEATED_ANNOTATION_WARNING!>@get:Ann(10)<!>
-<!REPEATED_ANNOTATION!>@get:Ann(20)<!>
+<!REPEATED_ANNOTATION, REPEATED_ANNOTATION_WARNING!>@get:Ann(20)<!>
 val d: String
     @Ann(30) <!REPEATED_ANNOTATION!>@Ann(40)<!> get() = "foo"

compiler/testData/diagnostics/tests/annotations/withUseSiteTarget/kt26638.txt

@@ -1,6 +1,9 @@
 package
 
-@setparam:Ann(x = 20) @setparam:Ann(x = 10) public var a: kotlin.String
+@get:Ann(x = 10) @get:Ann(x = 20) public val a: kotlin.String
+@set:Ann(x = 10) @set:Ann(x = 20) public var b: kotlin.String
+@setparam:Ann(x = 20) @setparam:Ann(x = 10) public var c: kotlin.String
+@get:Ann(x = 10) @get:Ann(x = 20) @get:Ann(x = 30) @get:Ann(x = 40) public val d: kotlin.String
 
 public final annotation class Ann : kotlin.Annotation {
     public constructor Ann(/*0*/ x: kotlin.Int)

compiler/testData/diagnostics/tests/annotations/withUseSiteTarget/kt26638_after.kt

@@ -0,0 +1,22 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !LANGUAGE: +ProhibitRepeatedUseSiteTargetAnnotations
+
+// Ann is not repeatable
+annotation class Ann(val x: Int)
+
+<!REPEATED_ANNOTATION!>@get:Ann(10)<!>
+val a: String
+    @Ann(20) get() = "foo"
+
+<!REPEATED_ANNOTATION!>@set:Ann(10)<!>
+var b: String = ""
+    @Ann(20) set(value) { field = value }
+
+<!REPEATED_ANNOTATION!>@setparam:Ann(10)<!>
+var c = " "
+    set(@Ann(20) x) {}
+
+<!REPEATED_ANNOTATION!>@get:Ann(10)<!>
+<!REPEATED_ANNOTATION!>@get:Ann(20)<!>
+val d: String
+    @Ann(30) <!REPEATED_ANNOTATION!>@Ann(40)<!> get() = "foo"

compiler/testData/diagnostics/tests/annotations/withUseSiteTarget/kt26638_after.txt

@@ -0,0 +1,14 @@
+package
+
+@get:Ann(x = 10) @get:Ann(x = 20) public val a: kotlin.String
+@set:Ann(x = 10) @set:Ann(x = 20) public var b: kotlin.String
+@setparam:Ann(x = 20) @setparam:Ann(x = 10) public var c: kotlin.String
+@get:Ann(x = 10) @get:Ann(x = 20) @get:Ann(x = 30) @get:Ann(x = 40) public val d: kotlin.String
+
+public final annotation class Ann : kotlin.Annotation {
+    public constructor Ann(/*0*/ x: kotlin.Int)
+    public final val x: kotlin.Int
+    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
+}

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

@@ -1449,6 +1449,11 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                     runTest("compiler/testData/diagnostics/tests/annotations/withUseSiteTarget/kt26638.kt");
                 }
 
+                @TestMetadata("kt26638_after.kt")
+                public void testKt26638_after() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/annotations/withUseSiteTarget/kt26638_after.kt");
+                }
+
                 @TestMetadata("ParamAnnotations.kt")
                 public void testParamAnnotations() throws Exception {
                     runTest("compiler/testData/diagnostics/tests/annotations/withUseSiteTarget/ParamAnnotations.kt");

compiler/tests/org/jetbrains/kotlin/checkers/javac/DiagnosticsUsingJavacTestGenerated.java

@@ -1444,6 +1444,11 @@ public class DiagnosticsUsingJavacTestGenerated extends AbstractDiagnosticsUsing
                     runTest("compiler/testData/diagnostics/tests/annotations/withUseSiteTarget/kt26638.kt");
                 }
 
+                @TestMetadata("kt26638_after.kt")
+                public void testKt26638_after() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/annotations/withUseSiteTarget/kt26638_after.kt");
+                }
+
                 @TestMetadata("ParamAnnotations.kt")
                 public void testParamAnnotations() throws Exception {
                     runTest("compiler/testData/diagnostics/tests/annotations/withUseSiteTarget/ParamAnnotations.kt");

compiler/util/src/org/jetbrains/kotlin/config/LanguageVersionSettings.kt

@@ -98,6 +98,7 @@ enum class LanguageFeature(
     ProhibitJvmOverloadsOnConstructorsOfAnnotationClasses(KOTLIN_1_4, kind = BUG_FIX),
     ProhibitTypeParametersInAnonymousObjects(KOTLIN_1_4, kind = BUG_FIX),
     ProperInlineFromHigherPlatformDiagnostic(KOTLIN_1_4, kind = BUG_FIX),
+    ProhibitRepeatedUseSiteTargetAnnotations(KOTLIN_1_4, kind = BUG_FIX),
 
     ProperVisibilityForCompanionObjectInstanceField(sinceVersion = null, kind = BUG_FIX),
     // Temporarily disabled, see KT-27084/KT-22379