KT-14282 No error on unused type alias with -language-version 1.0

Always resolve descriptors for type aliases.

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

@@ -123,7 +123,6 @@ public interface Errors {
     DiagnosticFactory0<KtParameter> REIFIED_TYPE_IN_CATCH_CLAUSE = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory0<KtTypeParameterList> GENERIC_THROWABLE_SUBCLASS = DiagnosticFactory0.create(ERROR);
 
-    DiagnosticFactory0<PsiElement> UNSUPPORTED_TYPEALIAS = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory1<KtElement, ClassifierDescriptor> RECURSIVE_TYPEALIAS_EXPANSION = DiagnosticFactory1.create(ERROR);
     DiagnosticFactory3<KtElement, KotlinType, KotlinType, ClassifierDescriptor> UPPER_BOUND_VIOLATED_IN_TYPEALIAS_EXPANSION =
             DiagnosticFactory3.create(ERROR);

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

@@ -425,7 +425,6 @@ public class DefaultErrorMessages {
         MAP.put(USELESS_ELVIS_RIGHT_IS_NULL, "Right operand of elvis operator (?:) is useless if it is null");
         MAP.put(CONFLICTING_UPPER_BOUNDS, "Upper bounds of {0} have empty intersection", NAME);
 
-        MAP.put(UNSUPPORTED_TYPEALIAS, "Type aliases are unsupported (min Kotlin language level: 1.1)");
         MAP.put(RECURSIVE_TYPEALIAS_EXPANSION, "Recursive type alias in expansion: {0}", NAME);
         MAP.put(UPPER_BOUND_VIOLATED_IN_TYPEALIAS_EXPANSION,
                 "Type argument resulting from type alias expansion is not within required bounds for ''{2}'': " +

compiler/frontend/src/org/jetbrains/kotlin/resolve/DescriptorResolver.java

@@ -667,7 +667,7 @@ public class DescriptorResolver {
         else if (!languageVersionSettings.supportsFeature(LanguageFeature.TypeAliases)) {
             typeResolver.resolveAbbreviatedType(scopeWithTypeParameters, typeReference, trace);
             PsiElement typeAliasKeyword = typeAlias.getTypeAliasKeyword();
-            trace.report(UNSUPPORTED_TYPEALIAS.on(typeAliasKeyword != null ? typeAliasKeyword : typeAlias));
+            trace.report(UNSUPPORTED_FEATURE.on(typeAliasKeyword != null ? typeAliasKeyword : typeAlias, LanguageFeature.TypeAliases));
             typeAliasDescriptor.initialize(
                     typeParameterDescriptors,
                     ErrorUtils.createErrorType(name.asString()),

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

@@ -19,7 +19,6 @@ package org.jetbrains.kotlin.resolve
 import com.google.common.collect.HashMultimap
 import com.google.common.collect.Multimap
 import com.intellij.psi.PsiElement
-import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.diagnostics.Errors.*
@@ -229,8 +228,6 @@ class LazyTopDownAnalyzer(
     }
 
     private fun createTypeAliasDescriptors(c: TopDownAnalysisContext, topLevelFqNames: Multimap<FqName, KtElement>, typeAliases: List<KtTypeAlias>) {
-        if (!languageVersionSettings.supportsFeature(LanguageFeature.TypeAliases)) return
-
         for (typeAlias in typeAliases) {
             val descriptor = lazyDeclarationResolver.resolveToDescriptor(typeAlias) as TypeAliasDescriptor
 

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

@@ -456,7 +456,7 @@ class TypeResolver(
             return createErrorTypeForTypeConstructor(c, projectionFromAllQualifierParts, typeConstructor)
         }
         if (!languageVersionSettings.supportsFeature(LanguageFeature.TypeAliases)) {
-            c.trace.report(UNSUPPORTED_TYPEALIAS.on(type))
+            c.trace.report(UNSUPPORTED_FEATURE.on(type, LanguageFeature.TypeAliases))
             return createErrorTypeForTypeConstructor(c, projectionFromAllQualifierParts, typeConstructor)
         }
 

compiler/testData/cli/jvm/unsupportedTypeAlias.args

@@ -0,0 +1,5 @@
+-language-version
+1.0
+$TESTDATA_DIR$/unsupportedTypeAlias.kt
+-d
+$TEMP_DIR$

compiler/testData/cli/jvm/unsupportedTypeAlias.kt

@@ -0,0 +1,3 @@
+package test
+
+typealias Unused = String

compiler/testData/cli/jvm/unsupportedTypeAlias.out

@@ -0,0 +1,4 @@
+compiler/testData/cli/jvm/unsupportedTypeAlias.kt:3:1: error: the feature is only available since Kotlin 1.1: type aliases
+typealias Unused = String
+^
+COMPILATION_ERROR

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

@@ -2,12 +2,13 @@
 
 class C
 
-<!UNSUPPORTED_TYPEALIAS!>typealias<!> S = String
+<!UNSUPPORTED_FEATURE!>typealias<!> S = String
-<!UNSUPPORTED_TYPEALIAS!>typealias<!> L<T> = List<T>
+<!UNSUPPORTED_FEATURE!>typealias<!> L<T> = List<T>
-<!UNSUPPORTED_TYPEALIAS!>typealias<!> CA = C
+<!UNSUPPORTED_FEATURE!>typealias<!> CA = C
+<!UNSUPPORTED_FEATURE!>typealias<!> Unused = Any
 
-val test1: <!UNSUPPORTED_TYPEALIAS!>S<!> = ""
+val test1: <!UNSUPPORTED_FEATURE!>S<!> = ""
 
-fun test2(x: <!UNSUPPORTED_TYPEALIAS!>L<<!UNSUPPORTED_TYPEALIAS!>S<!>><!>) = <!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>x<!>
+fun test2(x: <!UNSUPPORTED_FEATURE!>L<<!UNSUPPORTED_FEATURE!>S<!>><!>) = <!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>x<!>
 
-class Test3 : <!UNSUPPORTED_TYPEALIAS!>CA<!>()
+class Test3 : <!UNSUPPORTED_FEATURE!>CA<!>()

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

@@ -19,3 +19,4 @@ public final class Test3 {
 public typealias CA = [ERROR : CA]
 public typealias L</*0*/ T>  = [ERROR : L]
 public typealias S = [ERROR : S]
+public typealias Unused = [ERROR : Unused]

compiler/tests/org/jetbrains/kotlin/cli/CliTestGenerated.java

@@ -271,6 +271,12 @@ public class CliTestGenerated extends AbstractCliTest {
             doJvmTest(fileName);
         }
 
+        @TestMetadata("unsupportedTypeAlias.args")
+        public void testUnsupportedTypeAlias() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/cli/jvm/unsupportedTypeAlias.args");
+            doJvmTest(fileName);
+        }
+
         @TestMetadata("version.args")
         public void testVersion() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/cli/jvm/version.args");