Prohibit type parameters for local variables in LV >= 1.4 & -progressive

#KT-8341 Fixed

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

@@ -954,6 +954,8 @@ public interface Errors {
     DiagnosticFactory0<KtTypeReference> LOCAL_EXTENSION_PROPERTY = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory0<KtPropertyAccessor> LOCAL_VARIABLE_WITH_GETTER = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory0<KtPropertyAccessor> LOCAL_VARIABLE_WITH_SETTER = DiagnosticFactory0.create(ERROR);
+    DiagnosticFactory0<KtTypeParameterList> LOCAL_VARIABLE_WITH_TYPE_PARAMETERS_WARNING = DiagnosticFactory0.create(WARNING);
+    DiagnosticFactory0<KtTypeParameterList> LOCAL_VARIABLE_WITH_TYPE_PARAMETERS = DiagnosticFactory0.create(ERROR);
 
     DiagnosticFactory3<KtExpression, DeclarationDescriptor, Visibility, DeclarationDescriptor> INVISIBLE_SETTER = DiagnosticFactory3.create(ERROR);
 

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

@@ -399,6 +399,8 @@ public class DefaultErrorMessages {
         MAP.put(LOCAL_EXTENSION_PROPERTY, "Local extension properties are not allowed");
         MAP.put(LOCAL_VARIABLE_WITH_GETTER, "Local variables are not allowed to have getters");
         MAP.put(LOCAL_VARIABLE_WITH_SETTER, "Local variables are not allowed to have setters");
+        MAP.put(LOCAL_VARIABLE_WITH_TYPE_PARAMETERS_WARNING, "Type parameters for local variables are deprecated");
+        MAP.put(LOCAL_VARIABLE_WITH_TYPE_PARAMETERS, "Local variables are not allowed to have type parameters");
         MAP.put(VAL_WITH_SETTER, "A 'val'-property cannot have a setter");
 
         MAP.put(DEPRECATED_IDENTITY_EQUALS, "Identity equality for arguments of types {0} and {1} is deprecated", RENDER_TYPE, RENDER_TYPE);

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

@@ -33,7 +33,8 @@ private val DEFAULT_DECLARATION_CHECKERS = listOf(
     PropertiesWithBackingFieldsInsideInlineClass(),
     AnnotationClassTargetAndRetentionChecker(),
     ReservedMembersAndConstructsForInlineClass(),
-    ResultClassInReturnTypeChecker()
+    ResultClassInReturnTypeChecker(),
+    LocalVariableTypeParametersChecker()
 )
 
 private val DEFAULT_CALL_CHECKERS = listOf(

compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/LocalVariableTypeParametersChecker.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2010-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.resolve.checkers
+
+import org.jetbrains.kotlin.config.LanguageFeature
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
+import org.jetbrains.kotlin.descriptors.impl.LocalVariableDescriptor
+import org.jetbrains.kotlin.diagnostics.Errors
+import org.jetbrains.kotlin.psi.KtDeclaration
+import org.jetbrains.kotlin.psi.KtProperty
+
+class LocalVariableTypeParametersChecker : DeclarationChecker {
+    override fun check(declaration: KtDeclaration, descriptor: DeclarationDescriptor, context: DeclarationCheckerContext) {
+        if (declaration !is KtProperty || descriptor !is LocalVariableDescriptor) return
+
+        val typeParameters = declaration.typeParameters
+        val typeParametersList = declaration.typeParameterList
+        if (typeParameters.isEmpty() || typeParametersList == null) return
+
+        val diagnostic =
+            if (context.languageVersionSettings.supportsFeature(LanguageFeature.ProhibitTypeParametersForLocalVariables))
+                Errors.LOCAL_VARIABLE_WITH_TYPE_PARAMETERS
+            else
+                Errors.LOCAL_VARIABLE_WITH_TYPE_PARAMETERS_WARNING
+
+        context.trace.report(diagnostic.on(typeParametersList))
+    }
+}