Disallow arrays as upper bounds of type parameters

#KT-9189 Fixed

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/DefaultErrorMessagesJvm.java

@@ -24,8 +24,6 @@ import org.jetbrains.kotlin.diagnostics.rendering.Renderers;
 import org.jetbrains.kotlin.renderer.DescriptorRenderer;
 import org.jetbrains.kotlin.renderer.Renderer;
 
-import static org.jetbrains.kotlin.diagnostics.rendering.Renderers.STRING;
-
 public class DefaultErrorMessagesJvm implements DefaultErrorMessages.Extension {
 
     private static final Renderer<ConflictingJvmDeclarationsData> CONFLICTING_JVM_DECLARATIONS_DATA = new Renderer<ConflictingJvmDeclarationsData>() {
@@ -86,6 +84,8 @@ public class DefaultErrorMessagesJvm implements DefaultErrorMessages.Extension {
                 "Java type mismatch expected {1} but found {0}. Use explicit cast", Renderers.RENDER_TYPE, Renderers.RENDER_TYPE);
 
         MAP.put(ErrorsJvm.DUPLICATE_CLASS_NAMES, "Duplicate JVM class name ''{0}'' generated from: {1}", Renderers.TO_STRING, Renderers.TO_STRING);
+
+        MAP.put(ErrorsJvm.UPPER_BOUND_CANNOT_BE_ARRAY, "Upper bound of a type parameter cannot be an array");
     }
 
     @NotNull

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/ErrorsJvm.java

@@ -71,6 +71,8 @@ public interface ErrorsJvm {
 
     DiagnosticFactory2<PsiElement, String, String> DUPLICATE_CLASS_NAMES = DiagnosticFactory2.create(ERROR);
 
+    DiagnosticFactory0<PsiElement> UPPER_BOUND_CANNOT_BE_ARRAY = DiagnosticFactory0.create(ERROR);
+
     enum NullabilityInformationSource {
         KOTLIN {
             @NotNull

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/platform/JvmPlatformConfigurator.kt

@@ -16,6 +16,8 @@
 
 package org.jetbrains.kotlin.resolve.jvm.platform
 
+import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.builtins.KotlinBuiltIns.isArray
 import org.jetbrains.kotlin.cfg.WhenChecker
 import org.jetbrains.kotlin.container.StorageComponentContainer
 import org.jetbrains.kotlin.container.useImpl
@@ -70,7 +72,8 @@ public object JvmPlatformConfigurator : PlatformConfigurator(
                 ReifiedTypeParameterAnnotationChecker(),
                 NativeFunChecker(),
                 OverloadsAnnotationChecker(),
-                PublicFieldAnnotationChecker()
+                PublicFieldAnnotationChecker(),
+                TypeParameterBoundIsNotArrayChecker()
         ),
 
         additionalCallCheckers = listOf(
@@ -268,6 +271,26 @@ public class PublicFieldAnnotationChecker: DeclarationChecker {
     }
 }
 
+public class TypeParameterBoundIsNotArrayChecker : DeclarationChecker {
+    override fun check(
+            declaration: JetDeclaration,
+            descriptor: DeclarationDescriptor,
+            diagnosticHolder: DiagnosticSink,
+            bindingContext: BindingContext
+    ) {
+        val typeParameters = (descriptor as? CallableDescriptor)?.typeParameters
+                             ?: (descriptor as? ClassDescriptor)?.typeConstructor?.parameters
+                             ?: return
+
+        for (typeParameter in typeParameters) {
+            if (typeParameter.upperBounds.any { KotlinBuiltIns.isArray(it) || KotlinBuiltIns.isPrimitiveArray(it) }) {
+                val element = DescriptorToSourceUtils.descriptorToDeclaration(typeParameter) ?: declaration
+                diagnosticHolder.report(ErrorsJvm.UPPER_BOUND_CANNOT_BE_ARRAY.on(element))
+            }
+        }
+    }
+}
+
 public class ReifiedTypeParameterAnnotationChecker : DeclarationChecker {
 
     override fun check(

compiler/testData/diagnostics/tests/typeParameters/upperBoundCannotBeArray.kt

@@ -0,0 +1,18 @@
+fun <<!UPPER_BOUND_CANNOT_BE_ARRAY!>A : Array<Any><!>> f1() {}
+fun <T, <!UPPER_BOUND_CANNOT_BE_ARRAY!>A : Array<out T><!>> f2() {}
+fun <S, T : S, <!UPPER_BOUND_CANNOT_BE_ARRAY!>A : Array<out S><!>> f3() where A : Array<out T> {}
+
+fun <<!UPPER_BOUND_CANNOT_BE_ARRAY!>T : <!FINAL_UPPER_BOUND!>IntArray<!><!>> f4() {}
+
+fun <<!UPPER_BOUND_CANNOT_BE_ARRAY!>T<!>> f5() where T : Array<Any> {}
+
+val <<!UPPER_BOUND_CANNOT_BE_ARRAY!>T : Array<Any?><!>> v = ""
+
+class C2<T, <!UPPER_BOUND_CANNOT_BE_ARRAY!>A : Array<out T><!>>
+interface C3<S, T : S, <!UPPER_BOUND_CANNOT_BE_ARRAY!>A : Array<out S><!>> where A : Array<out T>
+
+fun foo() {
+    class C1<<!UPPER_BOUND_CANNOT_BE_ARRAY!>A : Array<Any><!>> {
+        fun <<!UPPER_BOUND_CANNOT_BE_ARRAY!>A : Array<Any><!>, <!UPPER_BOUND_CANNOT_BE_ARRAY!>B : Array<Any><!>, C : A> f() {}
+    }
+}

compiler/testData/diagnostics/tests/typeParameters/upperBoundCannotBeArray.txt

@@ -0,0 +1,22 @@
+package
+
+public val </*0*/ T : kotlin.Array<kotlin.Any?>> v: kotlin.String = ""
+public fun </*0*/ A : kotlin.Array<kotlin.Any>> f1(): kotlin.Unit
+public fun </*0*/ T, /*1*/ A : kotlin.Array<out T>> f2(): kotlin.Unit
+public fun </*0*/ S, /*1*/ T : S, /*2*/ A : kotlin.Array<out S>> f3(): kotlin.Unit where A : kotlin.Array<out T>
+public fun </*0*/ T : kotlin.IntArray> f4(): kotlin.Unit
+public fun </*0*/ T : kotlin.Array<kotlin.Any>> f5(): kotlin.Unit
+public fun foo(): kotlin.Unit
+
+public final class C2</*0*/ T, /*1*/ A : kotlin.Array<out T>> {
+    public constructor C2</*0*/ T, /*1*/ A : kotlin.Array<out T>>()
+    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 interface C3</*0*/ S, /*1*/ T : S, /*2*/ A : kotlin.Array<out S>> where A : kotlin.Array<out T> {
+    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/JetDiagnosticsTestGenerated.java

@@ -15151,6 +15151,21 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
             }
         }
 
+        @TestMetadata("compiler/testData/diagnostics/tests/typeParameters")
+        @TestDataPath("$PROJECT_ROOT")
+        @RunWith(JUnit3RunnerWithInners.class)
+        public static class TypeParameters extends AbstractJetDiagnosticsTest {
+            public void testAllFilesPresentInTypeParameters() throws Exception {
+                JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/diagnostics/tests/typeParameters"), Pattern.compile("^(.+)\\.kt$"), true);
+            }
+
+            @TestMetadata("upperBoundCannotBeArray.kt")
+            public void testUpperBoundCannotBeArray() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/typeParameters/upperBoundCannotBeArray.kt");
+                doTest(fileName);
+            }
+        }
+
         @TestMetadata("compiler/testData/diagnostics/tests/typedefs")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)