[FIR] optimize direct allocation of empty ConeTypeProjection arrays

On the snapshot from KTIJ-26260 empty ConeTypeProjection arrays take about 10mb

analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/stubBased/deserialization/StubBasedFirMemberDeserializer.kt

@@ -572,7 +572,7 @@ internal class StubBasedFirMemberDeserializer(
                 withPsiEntry("declaration", declaration)
             }
 
-        val enumType = ConeClassLikeTypeImpl(symbol.toLookupTag(), emptyArray(), false)
+        val enumType = ConeClassLikeTypeImpl(symbol.toLookupTag(), ConeTypeProjection.EMPTY_ARRAY, false)
         val enumEntry = buildEnumEntry {
             source = KtRealPsiSourceElement(declaration)
             this.moduleData = c.moduleData

compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeIntegerLiteralType.kt

@@ -14,7 +14,7 @@ sealed class ConeIntegerLiteralType(
     abstract val possibleTypes: Collection<ConeClassLikeType>
     abstract val supertypes: List<ConeClassLikeType>
 
-    final override val typeArguments: Array<out ConeTypeProjection> = emptyArray()
+    final override val typeArguments: Array<out ConeTypeProjection> get() = EMPTY_ARRAY
     final override val attributes: ConeAttributes get() = ConeAttributes.Empty
 
     abstract fun getApproximatedType(expectedType: ConeKotlinType? = null): ConeClassLikeType

compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeTypeVariableAndStubTypes.kt

@@ -16,7 +16,7 @@ class ConeTypeVariableType(
     override val lookupTag: ConeTypeVariableTypeConstructor,
     override val attributes: ConeAttributes = ConeAttributes.Empty,
 ) : ConeLookupTagBasedType() {
-    override val typeArguments: Array<out ConeTypeProjection> get() = emptyArray()
+    override val typeArguments: Array<out ConeTypeProjection> get() = EMPTY_ARRAY
     override fun equals(other: Any?): Boolean {
         if (this === other) return true
         if (other !is ConeTypeVariableType) return false
@@ -65,7 +65,7 @@ sealed class ConeStubType(val constructor: ConeStubTypeConstructor, override val
     ConeSimpleKotlinType() {
 
     override val typeArguments: Array<out ConeTypeProjection>
-        get() = emptyArray()
+        get() = EMPTY_ARRAY
 
     override val attributes: ConeAttributes
         get() = ConeAttributes.Empty

compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeTypes.kt

@@ -144,7 +144,7 @@ data class ConeCapturedType(
     )
 
     override val typeArguments: Array<out ConeTypeProjection>
-        get() = emptyArray()
+        get() = EMPTY_ARRAY
 
     override fun equals(other: Any?): Boolean {
         if (this === other) return true
@@ -220,7 +220,7 @@ class ConeIntersectionType(
     val alternativeType: ConeKotlinType? = null,
 ) : ConeSimpleKotlinType(), IntersectionTypeConstructorMarker {
     override val typeArguments: Array<out ConeTypeProjection>
-        get() = emptyArray()
+        get() = EMPTY_ARRAY
 
     override val nullability: ConeNullability
         get() = ConeNullability.NOT_NULL

compiler/fir/entrypoint/src/org/jetbrains/kotlin/fir/session/NativeForwardDeclarationsSymbolProvider.kt

@@ -26,6 +26,7 @@ import org.jetbrains.kotlin.fir.resolve.providers.FirSymbolProvider
 import org.jetbrains.kotlin.fir.resolve.providers.FirSymbolProviderInternals
 import org.jetbrains.kotlin.fir.scopes.FirKotlinScopeProvider
 import org.jetbrains.kotlin.fir.symbols.impl.*
+import org.jetbrains.kotlin.fir.types.ConeTypeProjection
 import org.jetbrains.kotlin.fir.types.builder.buildResolvedTypeRef
 import org.jetbrains.kotlin.fir.types.constructClassType
 import org.jetbrains.kotlin.fir.types.toLookupTag
@@ -125,7 +126,7 @@ class NativeForwardDeclarationsSymbolProvider(
                         NativeStandardInteropNames.ExperimentalForeignApi
                     )
                     type = annotationClassId.toLookupTag()
-                        .constructClassType(typeArguments = emptyArray(), isNullable = false)
+                        .constructClassType(typeArguments = ConeTypeProjection.EMPTY_ARRAY, isNullable = false)
                 }
                 argumentMapping = FirEmptyAnnotationArgumentMapping
             }

compiler/fir/fir-deserialization/src/org/jetbrains/kotlin/fir/deserialization/AbstractAnnotationDeserializer.kt

@@ -187,7 +187,7 @@ abstract class AbstractAnnotationDeserializer(
         val classId = nameResolver.getClassId(proto.id)
         return buildAnnotation {
             annotationTypeRef = buildResolvedTypeRef {
-                type = classId.toLookupTag().constructClassType(emptyArray(), isNullable = false)
+                type = classId.toLookupTag().constructClassType(ConeTypeProjection.EMPTY_ARRAY, isNullable = false)
             }
             session.lazyDeclarationResolver.disableLazyResolveContractChecksInside {
                 this.argumentMapping = createArgumentMapping(proto, classId, nameResolver)

compiler/fir/fir-deserialization/src/org/jetbrains/kotlin/fir/deserialization/ClassDeserialization.kt

@@ -26,6 +26,7 @@ import org.jetbrains.kotlin.fir.symbols.impl.FirEnumEntrySymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirNamedFunctionSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirRegularClassSymbol
 import org.jetbrains.kotlin.fir.types.ConeClassLikeType
+import org.jetbrains.kotlin.fir.types.ConeTypeProjection
 import org.jetbrains.kotlin.fir.types.builder.buildResolvedTypeRef
 import org.jetbrains.kotlin.fir.types.coneTypeSafe
 import org.jetbrains.kotlin.fir.types.impl.ConeClassLikeTypeImpl
@@ -168,7 +169,7 @@ fun deserializeClassToSymbol(
             classProto.enumEntryList.mapNotNull { enumEntryProto ->
                 val enumEntryName = nameResolver.getName(enumEntryProto.name)
 
-                val enumType = ConeClassLikeTypeImpl(symbol.toLookupTag(), emptyArray(), false)
+                val enumType = ConeClassLikeTypeImpl(symbol.toLookupTag(), ConeTypeProjection.EMPTY_ARRAY, false)
                 val property = buildEnumEntry {
                     this.moduleData = moduleData
                     this.origin = FirDeclarationOrigin.Library
@@ -265,7 +266,7 @@ fun FirRegularClassBuilder.addCloneForArrayIfNeeded(classId: ClassId, dispatchRe
     superTypeRefs += buildResolvedTypeRef {
         type = ConeClassLikeTypeImpl(
             StandardClassIds.Cloneable.toLookupTag(),
-            typeArguments = emptyArray(),
+            typeArguments = ConeTypeProjection.EMPTY_ARRAY,
             isNullable = false
         )
     }

compiler/fir/fir-deserialization/src/org/jetbrains/kotlin/fir/deserialization/FirEnumEntryDeserializerAccessUtil.kt

@@ -16,6 +16,7 @@ import org.jetbrains.kotlin.fir.references.builder.buildErrorNamedReference
 import org.jetbrains.kotlin.fir.references.builder.buildResolvedNamedReference
 import org.jetbrains.kotlin.fir.resolve.providers.getClassDeclaredPropertySymbols
 import org.jetbrains.kotlin.fir.resolve.providers.symbolProvider
+import org.jetbrains.kotlin.fir.types.ConeTypeProjection
 import org.jetbrains.kotlin.fir.types.builder.buildResolvedTypeRef
 import org.jetbrains.kotlin.fir.types.impl.ConeClassLikeTypeImpl
 import org.jetbrains.kotlin.fir.types.toLookupTag
@@ -45,7 +46,7 @@ fun FirEnumEntryDeserializedAccessExpression.toQualifiedPropertyAccessExpression
 
         typeRef = buildResolvedTypeRef {
             type = ConeClassLikeTypeImpl(
-                enumClassId.toLookupTag(), emptyArray(), isNullable = false
+                enumClassId.toLookupTag(), ConeTypeProjection.EMPTY_ARRAY, isNullable = false
             )
         }
     }

compiler/fir/fir2ir/jvm-backend/src/org/jetbrains/kotlin/fir/backend/jvm/FirJvmTypeMapper.kt

@@ -49,7 +49,7 @@ import org.jetbrains.org.objectweb.asm.Type
 class FirJvmTypeMapper(val session: FirSession) : FirSessionComponent {
     companion object {
         val NON_EXISTENT_ID = ClassId.topLevel(StandardNames.NON_EXISTENT_CLASS)
-        private val typeForNonExistentClass = NON_EXISTENT_ID.toLookupTag().constructClassType(emptyArray(), isNullable = false)
+        private val typeForNonExistentClass = NON_EXISTENT_ID.toLookupTag().constructClassType(ConeTypeProjection.EMPTY_ARRAY, isNullable = false)
     }
 
     fun mapType(

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/JavaTypeConversion.kt

@@ -217,7 +217,7 @@ private fun JavaClassifierType.toConeKotlinTypeForFlexibleBound(
                 else -> lowerBound?.typeArguments
             }
 
-            lookupTag.constructClassType(mappedTypeArguments ?: emptyArray(), isNullable = lowerBound != null, attributes)
+            lookupTag.constructClassType(mappedTypeArguments ?: ConeTypeProjection.EMPTY_ARRAY, isNullable = lowerBound != null, attributes)
         }
 
         is JavaTypeParameter -> {

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/deserialization/FirJvmDeserializationExtension.kt

@@ -10,6 +10,7 @@ import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.builder.FirRegularClassBuilder
 import org.jetbrains.kotlin.fir.deserialization.FirConstDeserializer
 import org.jetbrains.kotlin.fir.deserialization.FirDeserializationExtension
+import org.jetbrains.kotlin.fir.types.ConeTypeProjection
 import org.jetbrains.kotlin.fir.types.builder.buildResolvedTypeRef
 import org.jetbrains.kotlin.fir.types.impl.ConeClassLikeTypeImpl
 import org.jetbrains.kotlin.fir.types.toLookupTag
@@ -43,7 +44,7 @@ class FirJvmDeserializationExtension(session: FirSession) : FirDeserializationEx
         superTypeRefs += buildResolvedTypeRef {
             type = ConeClassLikeTypeImpl(
                 JAVA_IO_SERIALIZABLE.toLookupTag(),
-                typeArguments = emptyArray(),
+                typeArguments = ConeTypeProjection.EMPTY_ARRAY,
                 isNullable = false
             )
         }

compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/TypeExpansionUtils.kt

@@ -106,7 +106,7 @@ private fun mapTypeAliasArguments(
     useSiteSession: FirSession,
 ): ConeKotlinType {
     if (typeAlias.typeParameters.isNotEmpty() && abbreviatedType.typeArguments.isEmpty()) {
-        return resultingType.lookupTag.constructClassType(emptyArray(), resultingType.isNullable)
+        return resultingType.lookupTag.constructClassType(ConeTypeProjection.EMPTY_ARRAY, resultingType.isNullable)
     }
     val typeAliasMap = typeAlias.typeParameters.map { it.symbol }.zip(abbreviatedType.typeArguments).toMap()
 

compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/converter/LightTreeRawFirDeclarationBuilder.kt

@@ -44,6 +44,7 @@ import org.jetbrains.kotlin.fir.scopes.FirScopeProvider
 import org.jetbrains.kotlin.fir.symbols.FirBasedSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.*
 import org.jetbrains.kotlin.fir.types.ConeClassLikeType
+import org.jetbrains.kotlin.fir.types.ConeTypeProjection
 import org.jetbrains.kotlin.fir.types.FirTypeProjection
 import org.jetbrains.kotlin.fir.types.FirTypeRef
 import org.jetbrains.kotlin.fir.types.FirUserTypeRef
@@ -787,7 +788,7 @@ class LightTreeRawFirDeclarationBuilder(
                             delegatedSelfTypeRef = buildResolvedTypeRef {
                                 type = ConeClassLikeTypeImpl(
                                     this@buildAnonymousObject.symbol.toLookupTag(),
-                                    emptyArray(),
+                                    ConeTypeProjection.EMPTY_ARRAY,
                                     isNullable = false
                                 )
                             }.also { registerSelfType(it) },

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/BodyResolveUtils.kt

@@ -104,7 +104,7 @@ fun ConstantValueKind<*>.expectedConeType(session: FirSession): ConeKotlinType {
     fun constructLiteralType(classId: ClassId, isNullable: Boolean = false): ConeKotlinType {
         val symbol = session.symbolProvider.getClassLikeSymbolByClassId(classId)
             ?: return ConeErrorType(ConeSimpleDiagnostic("Missing stdlib class: $classId", DiagnosticKind.MissingStdlibClass))
-        return symbol.toLookupTag().constructClassType(emptyArray(), isNullable)
+        return symbol.toLookupTag().constructClassType(ConeTypeProjection.EMPTY_ARRAY, isNullable)
     }
     return when (this) {
         ConstantValueKind.Null -> session.builtinTypes.nullableNothingType.type

compiler/fir/tree/src/org/jetbrains/kotlin/fir/EnumClassUtils.kt

@@ -26,6 +26,7 @@ import org.jetbrains.kotlin.fir.expressions.builder.buildEmptyExpressionBlock
 import org.jetbrains.kotlin.fir.symbols.impl.FirNamedFunctionSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirPropertySymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirValueParameterSymbol
+import org.jetbrains.kotlin.fir.types.ConeTypeProjection
 import org.jetbrains.kotlin.fir.types.builder.buildResolvedTypeRef
 import org.jetbrains.kotlin.fir.types.impl.ConeClassLikeTypeImpl
 import org.jetbrains.kotlin.fir.types.toLookupTag
@@ -50,7 +51,11 @@ fun FirRegularClassBuilder.generateValuesFunction(
             type = ConeClassLikeTypeImpl(
                 StandardClassIds.Array.toLookupTag(),
                 arrayOf(
-                    ConeClassLikeTypeImpl(this@generateValuesFunction.symbol.toLookupTag(), emptyArray(), isNullable = false)
+                    ConeClassLikeTypeImpl(
+                        this@generateValuesFunction.symbol.toLookupTag(),
+                        ConeTypeProjection.EMPTY_ARRAY,
+                        isNullable = false
+                    )
                 ),
                 isNullable = false
             )
@@ -145,7 +150,7 @@ fun FirRegularClassBuilder.generateEntriesGetter(
             type = ConeClassLikeTypeImpl(
                 StandardClassIds.EnumEntries.toLookupTag(),
                 arrayOf(
-                    ConeClassLikeTypeImpl(this@generateEntriesGetter.symbol.toLookupTag(), emptyArray(), isNullable = false)
+                    ConeClassLikeTypeImpl(this@generateEntriesGetter.symbol.toLookupTag(), ConeTypeProjection.EMPTY_ARRAY, isNullable = false)
                 ),
                 isNullable = false
             )

compiler/fir/tree/src/org/jetbrains/kotlin/fir/Primitives.kt

@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.fir.declarations.FirClass
 import org.jetbrains.kotlin.fir.declarations.utils.classId
 import org.jetbrains.kotlin.fir.symbols.impl.FirClassSymbol
 import org.jetbrains.kotlin.fir.types.ConeClassLikeType
+import org.jetbrains.kotlin.fir.types.ConeTypeProjection
 import org.jetbrains.kotlin.fir.types.impl.ConeClassLikeTypeImpl
 import org.jetbrains.kotlin.fir.types.toLookupTag
 import org.jetbrains.kotlin.name.ClassId
@@ -29,7 +30,7 @@ object StandardTypes {
 }
 
 private fun ClassId.createType(isNullable: Boolean = false): ConeClassLikeType =
-    ConeClassLikeTypeImpl(this.toLookupTag(), emptyArray(), isNullable)
+    ConeClassLikeTypeImpl(this.toLookupTag(), ConeTypeProjection.EMPTY_ARRAY, isNullable)
 
 fun ConeClassLikeType.isDouble(): Boolean = lookupTag.classId == StandardClassIds.Double
 fun ConeClassLikeType.isFloat(): Boolean = lookupTag.classId == StandardClassIds.Float

compiler/fir/tree/src/org/jetbrains/kotlin/fir/types/ConeIntegerLiteralTypeImpl.kt

@@ -84,7 +84,7 @@ class ConeIntegerLiteralConstantTypeImpl(
         }
 
         private fun createType(classId: ClassId): ConeClassLikeType {
-            return ConeClassLikeTypeImpl(classId.toLookupTag(), emptyArray(), false)
+            return ConeClassLikeTypeImpl(classId.toLookupTag(), EMPTY_ARRAY, false)
         }
 
         private val INT_RANGE = Int.MIN_VALUE.toLong()..Int.MAX_VALUE.toLong()
@@ -147,7 +147,7 @@ private object ConeIntegerLiteralTypeExtensions {
     }
 
     fun createClassLikeType(classId: ClassId): ConeClassLikeType {
-        return ConeClassLikeTypeImpl(classId.toLookupTag(), emptyArray(), false)
+        return ConeClassLikeTypeImpl(classId.toLookupTag(), ConeTypeProjection.EMPTY_ARRAY, false)
     }
 
     fun ConeIntegerLiteralType.getApproximatedTypeImpl(expectedType: ConeKotlinType?): ConeClassLikeType {

plugins/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/types/FirNumberSignAttributeExtension.kt

@@ -43,7 +43,7 @@ class FirNumberSignAttributeExtension(session: FirSession) : FirTypeAttributeExt
             annotationTypeRef = buildResolvedTypeRef {
                 type = ConeClassLikeTypeImpl(
                     classId.toLookupTag(),
-                    emptyArray(),
+                    ConeTypeProjection.EMPTY_ARRAY,
                     isNullable = false
                 )
             }

plugins/parcelize/parcelize-compiler/parcelize.k2/src/org/jetbrains/kotlin/parcelize/fir/diagnostics/FirParcelizeClassChecker.kt

@@ -78,7 +78,7 @@ object FirParcelizeClassChecker : FirClassChecker() {
             val superType = superTypeRef.coneType
             val parcelableType = ConeClassLikeTypeImpl(
                 PARCELABLE_ID.toLookupTag(),
-                emptyArray(),
+                ConeTypeProjection.EMPTY_ARRAY,
                 isNullable = false
             )
             if (superType.isSubtypeOf(parcelableType, context.session)) {