Correct diagnostics and quick-fix for T::class with non-reified type parameter #KT-9590 fixed

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/checkers/ReifiedTypeParameterSubstitutionChecker.java

@@ -50,7 +50,7 @@ public class ReifiedTypeParameterSubstitutionChecker implements CallChecker {
 
             if (argumentDeclarationDescriptor instanceof TypeParameterDescriptor &&
                 !((TypeParameterDescriptor) argumentDeclarationDescriptor).isReified()) {
-                context.getTrace().report(Errors.TYPE_PARAMETER_AS_REIFIED.on(reportErrorOn, parameter));
+                context.getTrace().report(Errors.TYPE_PARAMETER_AS_REIFIED.on(reportErrorOn, (TypeParameterDescriptor) argumentDeclarationDescriptor));
             }
             else if (TypeUtilsKt.cannotBeReified(argument)) {
                 context.getTrace().report(Errors.REIFIED_TYPE_FORBIDDEN_SUBSTITUTION.on(reportErrorOn, argument));

compiler/frontend/src/org/jetbrains/kotlin/types/expressions/DoubleColonExpressionResolver.kt

@@ -48,12 +48,11 @@ import org.jetbrains.kotlin.resolve.scopes.receivers.ExpressionReceiver
 import org.jetbrains.kotlin.resolve.scopes.receivers.Receiver
 import org.jetbrains.kotlin.resolve.scopes.receivers.TransientReceiver
 import org.jetbrains.kotlin.resolve.source.toSourceElement
-import org.jetbrains.kotlin.types.ErrorUtils
-import org.jetbrains.kotlin.types.KotlinType
-import org.jetbrains.kotlin.types.KotlinTypeFactory
-import org.jetbrains.kotlin.types.TypeUtils
+import org.jetbrains.kotlin.types.*
 import org.jetbrains.kotlin.types.TypeUtils.NO_EXPECTED_TYPE
 import org.jetbrains.kotlin.types.expressions.typeInfoFactory.createTypeInfo
+import org.jetbrains.kotlin.types.typeUtil.isTypeParameter
+import java.lang.UnsupportedOperationException
 import javax.inject.Inject
 
 sealed class DoubleColonLHS(val type: KotlinType) {
@@ -119,7 +118,12 @@ class DoubleColonExpressionResolver(
             reportError = !isAllowedInClassLiteral(type)
         }
 
-        if (type.isMarkedNullable || reportError) {
+
+        val typeParameterDescriptor = TypeUtils.getTypeParameterDescriptorOrNull(type)
+        if (type is SimpleType && !type.isMarkedNullable && typeParameterDescriptor != null && !typeParameterDescriptor.isReified) {
+            c.trace.report(TYPE_PARAMETER_AS_REIFIED.on(expression, typeParameterDescriptor))
+        }
+        else if (type.isMarkedNullable || reportError) {
             c.trace.report(CLASS_LITERAL_LHS_NOT_A_CLASS.on(expression))
         }
     }

compiler/testData/diagnostics/tests/classLiteral/nonClassesOnLHS.kt

@@ -9,7 +9,7 @@ val l1 = <!CLASS_LITERAL_LHS_NOT_A_CLASS!>List<String>?::class<!>
 val l2 = <!CLASS_LITERAL_LHS_NOT_A_CLASS!>List?::class<!>
 
 fun <T : Any> foo() {
-    val t1 = <!CLASS_LITERAL_LHS_NOT_A_CLASS!>T::class<!>
+    val t1 = <!TYPE_PARAMETER_AS_REIFIED!>T::class<!>
     val t2 = <!CLASS_LITERAL_LHS_NOT_A_CLASS!>T?::class<!>
 }
 

compiler/testData/diagnostics/tests/generics/tpAsReified/ClassDereference.kt

@@ -0,0 +1,3 @@
+
+fun <T: Any> dereferenceClass(): Any =
+        <!TYPE_PARAMETER_AS_REIFIED!>T::class<!>

compiler/testData/diagnostics/tests/generics/tpAsReified/ClassDereference.txt

@@ -0,0 +1,3 @@
+package
+
+public fun </*0*/ T : kotlin.Any> dereferenceClass(): kotlin.Any

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

@@ -8339,6 +8339,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                     doTest(fileName);
                 }
 
+                @TestMetadata("ClassDereference.kt")
+                public void testClassDereference() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/generics/tpAsReified/ClassDereference.kt");
+                    doTest(fileName);
+                }
+
                 @TestMetadata("Conventions.kt")
                 public void testConventions() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/generics/tpAsReified/Conventions.kt");