Minor, make CompanionObjectMapping a singleton

compiler/backend/src/org/jetbrains/kotlin/codegen/FieldInfo.java

@@ -27,24 +27,20 @@ import org.jetbrains.org.objectweb.asm.Type;
 import static org.jetbrains.kotlin.resolve.DescriptorUtils.isNonCompanionObject;
 
 public class FieldInfo {
-
-    private static final CompanionObjectMapping COMPANION_OBJECT_MAPPING = new CompanionObjectMapping();
-
     @NotNull
     public static FieldInfo createForSingleton(@NotNull ClassDescriptor classDescriptor, @NotNull KotlinTypeMapper typeMapper) {
         if (!classDescriptor.getKind().isSingleton() || DescriptorUtils.isEnumEntry(classDescriptor)) {
             throw new UnsupportedOperationException("Can't create singleton field for class: " + classDescriptor);
         }
 
-        if (isNonCompanionObject(classDescriptor) || COMPANION_OBJECT_MAPPING.hasMappingToObject(classDescriptor)) {
+        if (isNonCompanionObject(classDescriptor) || CompanionObjectMapping.INSTANCE.hasMappingToObject(classDescriptor)) {
             return createSingletonViaInstance(classDescriptor, typeMapper);
         }
-        else {
+
-            ClassDescriptor ownerDescriptor = DescriptorUtils.getParentOfType(classDescriptor, ClassDescriptor.class);
+        ClassDescriptor ownerDescriptor = DescriptorUtils.getParentOfType(classDescriptor, ClassDescriptor.class);
-            assert ownerDescriptor != null : "Owner not found for class: " + classDescriptor;
+        assert ownerDescriptor != null : "Owner not found for class: " + classDescriptor;
-            Type ownerType = typeMapper.mapType(ownerDescriptor);
+        Type ownerType = typeMapper.mapType(ownerDescriptor);
-            return new FieldInfo(ownerType, typeMapper.mapType(classDescriptor), classDescriptor.getName().asString(), true);
+        return new FieldInfo(ownerType, typeMapper.mapType(classDescriptor), classDescriptor.getName().asString(), true);
-        }
     }
 
     @NotNull

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/JvmAbi.java

@@ -18,6 +18,7 @@ package org.jetbrains.kotlin.load.java;
 
 import kotlin.text.Regex;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.kotlin.builtins.CompanionObjectMapping;
 import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor;
 import org.jetbrains.kotlin.descriptors.ClassDescriptor;
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor;
@@ -25,7 +26,6 @@ import org.jetbrains.kotlin.descriptors.PropertyDescriptor;
 import org.jetbrains.kotlin.name.ClassId;
 import org.jetbrains.kotlin.name.FqName;
 import org.jetbrains.kotlin.name.Name;
-import org.jetbrains.kotlin.platform.JavaToKotlinClassMap;
 import org.jetbrains.kotlin.util.capitalizeDecapitalize.CapitalizeDecapitalizeKt;
 
 import static org.jetbrains.kotlin.resolve.DescriptorUtils.isClassOrEnumClass;
@@ -103,7 +103,6 @@ public final class JvmAbi {
     public static boolean isCompanionObjectWithBackingFieldsInOuter(@NotNull DeclarationDescriptor companionObject) {
         return isCompanionObject(companionObject) &&
                isClassOrEnumClass(companionObject.getContainingDeclaration()) &&
-               !JavaToKotlinClassMap.INSTANCE.isMappedCompanion((ClassDescriptor) companionObject);
+               !CompanionObjectMapping.INSTANCE.hasMappingToObject((ClassDescriptor) companionObject);
     }
 }
-

core/descriptor.loader.java/src/org/jetbrains/kotlin/platform/JavaToKotlinClassMap.java

@@ -43,7 +43,6 @@ public class JavaToKotlinClassMap implements PlatformToKotlinClassMap {
 
     private final Map<FqNameUnsafe, FqName> mutableToReadOnly = new HashMap<FqNameUnsafe, FqName>();
     private final Map<FqNameUnsafe, FqName> readOnlyToMutable = new HashMap<FqNameUnsafe, FqName>();
-    private final CompanionObjectMapping companionObjectMapping;
 
     private JavaToKotlinClassMap() {
         add(Object.class, FQ_NAMES.any);
@@ -69,8 +68,7 @@ public class JavaToKotlinClassMap implements PlatformToKotlinClassMap {
             add(ClassId.topLevel(jvmType.getWrapperFqName()), KotlinBuiltIns.getPrimitiveFqName(jvmType.getPrimitiveType()));
         }
 
-        companionObjectMapping = new CompanionObjectMapping();
+        for (FqName fqName : CompanionObjectMapping.INSTANCE.allClassesWithIntrinsicCompanions()) {
-        for (FqName fqName : companionObjectMapping.allClassesWithIntrinsicCompanions()) {
             add(ClassId.topLevel(
                     new FqName("kotlin.jvm.internal." + fqName.shortName().asString() + "CompanionObject")),
                     fqName.child(SpecialNames.DEFAULT_NAME_FOR_COMPANION_OBJECT));
@@ -119,10 +117,6 @@ public class JavaToKotlinClassMap implements PlatformToKotlinClassMap {
         return kotlinToJava.get(kotlinFqName);
     }
 
-    public boolean isMappedCompanion(@NotNull ClassDescriptor descriptor) {
-        return companionObjectMapping.hasMappingToObject(descriptor);
-    }
-
     private void add(
             @NotNull Class<?> javaClass,
             @NotNull FqName kotlinReadOnlyFqName,

core/descriptors/src/org/jetbrains/kotlin/builtins/CompanionObjectMapping.kt

@@ -21,7 +21,7 @@ import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.resolve.DescriptorUtils
 import java.util.*
 
-class CompanionObjectMapping {
+object CompanionObjectMapping {
     private val classesFqNames = linkedSetOf<FqName>()
 
     init {

js/js.translator/src/org/jetbrains/kotlin/js/translate/intrinsic/objects/objectsIntrinsics.kt

@@ -33,10 +33,8 @@ class DefaultClassObjectIntrinsic(val fqName: FqName): ObjectIntrinsic {
 }
 
 class ObjectIntrinsics {
-    private val companionObjectMapping = CompanionObjectMapping()
-
     fun getIntrinsic(classDescriptor: ClassDescriptor): ObjectIntrinsic {
-        if (!companionObjectMapping.hasMappingToObject(classDescriptor)) return NO_OBJECT_INTRINSIC
+        if (!CompanionObjectMapping.hasMappingToObject(classDescriptor)) return NO_OBJECT_INTRINSIC
 
         val containingDeclaration = classDescriptor.containingDeclaration
         val name = Name.identifier(containingDeclaration.name.asString() + "CompanionObject")