Get rid of excess method in compiled inline class with custom equals

^KT-54501: Fixed

compiler/ir/backend.jvm/lower/src/org/jetbrains/kotlin/backend/jvm/lower/JvmInlineClassLowering.kt

@@ -5,6 +5,7 @@
 
 package org.jetbrains.kotlin.backend.jvm.lower
 
+import org.jetbrains.kotlin.backend.common.lower.MethodsFromAnyGeneratorForLowerings.Companion.isEquals
 import org.jetbrains.kotlin.backend.common.lower.createIrBuilder
 import org.jetbrains.kotlin.backend.common.lower.irBlockBody
 import org.jetbrains.kotlin.backend.common.lower.loops.forLoopsPhase
@@ -28,8 +29,8 @@ import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
 import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.resolve.InlineClassDescriptorResolver
 import org.jetbrains.kotlin.resolve.JVM_INLINE_ANNOTATION_FQ_NAME
-import org.jetbrains.kotlin.util.OperatorNameConventions.EQUALS
 
 val jvmInlineClassPhase = makeIrFilePhase(
     ::JvmInlineClassLowering,
@@ -118,7 +119,7 @@ private class JvmInlineClassLowering(context: JvmBackendContext) : JvmValueClass
         buildPrimaryInlineClassConstructor(declaration, irConstructor)
         buildBoxFunction(declaration)
         buildUnboxFunction(declaration)
-        buildSpecializedEqualsMethod(declaration)
+        buildSpecializedEqualsMethodIfNeeded(declaration)
         addJvmInlineAnnotation(declaration)
     }
 
@@ -479,35 +480,29 @@ private class JvmInlineClassLowering(context: JvmBackendContext) : JvmValueClass
         irClass.declarations += function
     }
 
-    fun buildSpecializedEqualsMethod(valueClass: IrClass) {
+    fun buildSpecializedEqualsMethodIfNeeded(valueClass: IrClass) {
         val function = context.inlineClassReplacements.getSpecializedEqualsMethod(valueClass, context.irBuiltIns)
+        // Return if we have already built specialized equals as static replacement of typed equals
+        if (function.body != null) return
         val left = function.valueParameters[0]
         val right = function.valueParameters[1]
         val type = left.type.unboxInlineClass()
 
-        val typedEqualsStaticReplacement = findStaticReplacementForTypedEquals(valueClass)
-        val untypedEquals = valueClass.functions.single { it.overridesEqualsFromAny }
+        val untypedEquals = valueClass.functions.single { it.isEquals(context) }
 
         function.body = context.createIrBuilder(valueClass.symbol).run {
             irExprBody(
-                if (typedEqualsStaticReplacement == null) {
-                    if (untypedEquals.origin == IrDeclarationOrigin.DEFINED) {
-                        val boxFunction = this@JvmInlineClassLowering.context.inlineClassReplacements.getBoxFunction(valueClass)
+                if (untypedEquals.origin == IrDeclarationOrigin.DEFINED) {
+                    val boxFunction = this@JvmInlineClassLowering.context.inlineClassReplacements.getBoxFunction(valueClass)
 
-                        fun irBox(expr: IrExpression) = irCall(boxFunction).apply { putValueArgument(0, expr) }
+                    fun irBox(expr: IrExpression) = irCall(boxFunction).apply { putValueArgument(0, expr) }
 
-                        irCall(untypedEquals).apply {
-                            dispatchReceiver = irBox(irGet(left))
-                            putValueArgument(0, irBox(irGet(right)))
-                        }
-                    } else {
-                        irEquals(coerceInlineClasses(irGet(left), left.type, type), coerceInlineClasses(irGet(right), right.type, type))
+                    irCall(untypedEquals).apply {
+                        dispatchReceiver = irBox(irGet(left))
+                        putValueArgument(0, irBox(irGet(right)))
                     }
                 } else {
-                    irCall(typedEqualsStaticReplacement).apply {
-                        putValueArgument(0, irGet(left))
-                        putValueArgument(1, irGet(right))
-                    }
+                    irEquals(coerceInlineClasses(irGet(left), left.type, type), coerceInlineClasses(irGet(right), right.type, type))
                 }
             )
         }
@@ -515,15 +510,4 @@ private class JvmInlineClassLowering(context: JvmBackendContext) : JvmValueClass
         valueClass.declarations += function
     }
 
-    private fun findStaticReplacementForTypedEquals(valueClass: IrClass): IrFunction? {
-        fun isTypedEquals(irFunction: IrFunction): Boolean {
-            return irFunction.run {
-                name == EQUALS && returnType.isBoolean() && valueParameters.size == 1
-                        && (valueParameters[0].type.classFqName?.run { valueClass.hasEqualFqName(this) } ?: false)
-                        && contextReceiverParametersCount == 0 && extensionReceiverParameter == null
-            }
-        }
-        return valueClass.functions
-            .singleOrNull { context.inlineClassReplacements.originalFunctionForStaticReplacement[it]?.run { isTypedEquals(this) } ?: false }
-    }
 }

compiler/ir/backend.jvm/lower/src/org/jetbrains/kotlin/backend/jvm/lower/JvmValueClassAbstractLowering.kt

@@ -184,6 +184,7 @@ internal abstract class JvmValueClassAbstractLowering(val context: JvmBackendCon
             function,
             replacement,
             when {
+                function.isTypedEquals -> InlineClassAbi.mangledNameFor(function, mangleReturnTypes = false, useOldMangleRules = false)
                 // If the original function has signature which need mangling we still need to replace it with a mangled version.
                 (!function.isFakeOverride || function.findInterfaceImplementation(context.state.jvmDefaultMode) != null) && when (specificMangle) {
                     SpecificMangle.Inline -> function.signatureRequiresMangling(includeInline = true, includeMFVC = false)

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/MemoizedInlineClassReplacements.kt

@@ -64,6 +64,11 @@ class MemoizedInlineClassReplacements(
                 // Mangle all functions in the body of an inline class
                 it.parent.safeAs<IrClass>()?.isSingleFieldValueClass == true ->
                     when {
+                        it.isTypedEquals -> createStaticReplacement(it).also {
+                            it.name = InlineClassDescriptorResolver.SPECIALIZED_EQUALS_NAME
+                            specializedEqualsCache.computeIfAbsent(it.parentAsClass) { it }
+                        }
+
                         it.isRemoveAtSpecialBuiltinStub() ->
                             null
                         it.isValueClassMemberFakeOverriddenFromJvmDefaultInterfaceMethod() ||

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt

@@ -1308,6 +1308,10 @@ fun IrBuiltIns.getKFunctionType(returnType: IrType, parameterTypes: List<IrType>
 fun IdSignature?.isComposite(): Boolean =
     this is IdSignature.CompositeSignature
 
-val IrFunction.overridesEqualsFromAny
-    get() = name == OperatorNameConventions.EQUALS && valueParameters.size == 1 && valueParameters[0].type.isNullableAny()
-            && contextReceiverParametersCount == 0 && extensionReceiverParameter == null
+val IrFunction.isTypedEquals: Boolean
+    get() {
+        val parentClass = parent as? IrClass ?: return false
+        return name == OperatorNameConventions.EQUALS && returnType.isBoolean() && valueParameters.size == 1
+                && (valueParameters[0].type.classFqName?.run { parentClass.hasEqualFqName(this) } ?: false)
+                && contextReceiverParametersCount == 0 && extensionReceiverParameter == null && parentClass.isValue
+    }

compiler/testData/codegen/box/callableReference/kt49526.kt

@@ -1,7 +1,6 @@
 // WITH_STDLIB
 // CHECK_BYTECODE_LISTING
 // FIR_IDENTICAL
-// FIR_IDENTICAL
 
 inline fun <T> useRef(value: T, f: (T) -> Boolean) = f(value)
 

compiler/testData/codegen/box/inlineClasses/inlineClassEqualsOverride.fir.txt

@@ -0,0 +1,88 @@
+@kotlin.Metadata
+public interface I {
+    // source: 'inlineClassEqualsOverride.kt'
+    public abstract method equals-ACFGG4I(p0: int): boolean
+}
+
+@kotlin.jvm.JvmInline
+@kotlin.Metadata
+public final class IC1 {
+    // source: 'inlineClassEqualsOverride.kt'
+    private final field value: double
+    private synthetic method <init>(p0: double): void
+    public synthetic final static method box-impl(p0: double): IC1
+    public static method constructor-impl(p0: double): double
+    public method equals(p0: java.lang.Object): boolean
+    public static method equals-impl(p0: double, p1: java.lang.Object): boolean
+    public final static method equals-impl0(p0: double, p1: double): boolean
+    public final method getValue(): double
+    public method hashCode(): int
+    public static method hashCode-impl(p0: double): int
+    public method toString(): java.lang.String
+    public static method toString-impl(p0: double): java.lang.String
+    public synthetic final method unbox-impl(): double
+}
+
+@kotlin.jvm.JvmInline
+@kotlin.Metadata
+public final class IC2 {
+    // source: 'inlineClassEqualsOverride.kt'
+    private final field value: int
+    private synthetic method <init>(p0: int): void
+    public synthetic final static method box-impl(p0: int): IC2
+    public static method constructor-impl(p0: int): int
+    public method equals(p0: java.lang.Object): boolean
+    public final method equals-ACFGG4I(p0: int): boolean
+    public static method equals-impl(p0: int, p1: java.lang.Object): boolean
+    public final static method equals-impl0(p0: int, p1: int): boolean
+    public final method getValue(): int
+    public method hashCode(): int
+    public static method hashCode-impl(p0: int): int
+    public method toString(): java.lang.String
+    public static method toString-impl(p0: int): java.lang.String
+    public synthetic final method unbox-impl(): int
+}
+
+@kotlin.jvm.JvmInline
+@kotlin.Metadata
+public final class IC3 {
+    // source: 'inlineClassEqualsOverride.kt'
+    private final field value: int
+    private synthetic method <init>(p0: int): void
+    public synthetic final static method box-impl(p0: int): IC3
+    public static method constructor-impl(p0: int): int
+    public method equals(p0: java.lang.Object): boolean
+    public static method equals-impl(p0: int, p1: java.lang.Object): boolean
+    public final static method equals-impl0(p0: int, p1: int): boolean
+    public final method getValue(): int
+    public method hashCode(): int
+    public static method hashCode-impl(p0: int): int
+    public method toString(): java.lang.String
+    public static method toString-impl(p0: int): java.lang.String
+    public synthetic final method unbox-impl(): int
+}
+
+@kotlin.jvm.JvmInline
+@kotlin.Metadata
+public final class IC4 {
+    // source: 'inlineClassEqualsOverride.kt'
+    private final field value: int
+    private synthetic method <init>(p0: int): void
+    public synthetic final static method box-impl(p0: int): IC4
+    public static method constructor-impl(p0: int): int
+    public final @org.jetbrains.annotations.NotNull method equals(@org.jetbrains.annotations.Nullable p0: java.lang.Object): java.lang.Void
+    public final static @org.jetbrains.annotations.NotNull method equals-impl(p0: int, @org.jetbrains.annotations.Nullable p1: java.lang.Object): java.lang.Void
+    public final static method equals-impl0(p0: int, p1: int): boolean
+    public final method getValue(): int
+    public method hashCode(): int
+    public static method hashCode-impl(p0: int): int
+    public method toString(): java.lang.String
+    public static method toString-impl(p0: int): java.lang.String
+    public synthetic final method unbox-impl(): int
+}
+
+@kotlin.Metadata
+public final class InlineClassEqualsOverrideKt {
+    // source: 'inlineClassEqualsOverride.kt'
+    public final static @org.jetbrains.annotations.NotNull method box(): java.lang.String
+}

compiler/testData/codegen/box/inlineClasses/inlineClassEqualsOverride.kt

@@ -2,6 +2,7 @@
 // WORKS_WHEN_VALUE_CLASS
 // LANGUAGE: +ValueClasses, +CustomEqualsInInlineClasses
 // TARGET_BACKEND: JVM_IR
+// CHECK_BYTECODE_LISTING
 
 import kotlin.math.abs
 

compiler/testData/codegen/box/inlineClasses/inlineClassEqualsOverride.txt

@@ -0,0 +1,88 @@
+@kotlin.Metadata
+public interface I {
+    // source: 'inlineClassEqualsOverride.kt'
+    public abstract method equals-ACFGG4I(p0: int): boolean
+}
+
+@kotlin.jvm.JvmInline
+@kotlin.Metadata
+public final class IC1 {
+    // source: 'inlineClassEqualsOverride.kt'
+    private final field value: double
+    private synthetic method <init>(p0: double): void
+    public synthetic final static method box-impl(p0: double): IC1
+    public static method constructor-impl(p0: double): double
+    public method equals(p0: java.lang.Object): boolean
+    public static method equals-impl(p0: double, p1: java.lang.Object): boolean
+    public final static method equals-impl0(p0: double, p1: double): boolean
+    public final method getValue(): double
+    public method hashCode(): int
+    public static method hashCode-impl(p0: double): int
+    public method toString(): java.lang.String
+    public static method toString-impl(p0: double): java.lang.String
+    public synthetic final method unbox-impl(): double
+}
+
+@kotlin.jvm.JvmInline
+@kotlin.Metadata
+public final class IC2 {
+    // source: 'inlineClassEqualsOverride.kt'
+    private final field value: int
+    private synthetic method <init>(p0: int): void
+    public synthetic final static method box-impl(p0: int): IC2
+    public static method constructor-impl(p0: int): int
+    public method equals(p0: java.lang.Object): boolean
+    public method equals-ACFGG4I(p0: int): boolean
+    public static method equals-impl(p0: int, p1: java.lang.Object): boolean
+    public static method equals-impl0(p0: int, p1: int): boolean
+    public final method getValue(): int
+    public method hashCode(): int
+    public static method hashCode-impl(p0: int): int
+    public method toString(): java.lang.String
+    public static method toString-impl(p0: int): java.lang.String
+    public synthetic final method unbox-impl(): int
+}
+
+@kotlin.jvm.JvmInline
+@kotlin.Metadata
+public final class IC3 {
+    // source: 'inlineClassEqualsOverride.kt'
+    private final field value: int
+    private synthetic method <init>(p0: int): void
+    public synthetic final static method box-impl(p0: int): IC3
+    public static method constructor-impl(p0: int): int
+    public method equals(p0: java.lang.Object): boolean
+    public static method equals-impl(p0: int, p1: java.lang.Object): boolean
+    public final static method equals-impl0(p0: int, p1: int): boolean
+    public final method getValue(): int
+    public method hashCode(): int
+    public static method hashCode-impl(p0: int): int
+    public method toString(): java.lang.String
+    public static method toString-impl(p0: int): java.lang.String
+    public synthetic final method unbox-impl(): int
+}
+
+@kotlin.jvm.JvmInline
+@kotlin.Metadata
+public final class IC4 {
+    // source: 'inlineClassEqualsOverride.kt'
+    private final field value: int
+    private synthetic method <init>(p0: int): void
+    public synthetic final static method box-impl(p0: int): IC4
+    public static method constructor-impl(p0: int): int
+    public @org.jetbrains.annotations.NotNull method equals(@org.jetbrains.annotations.Nullable p0: java.lang.Object): java.lang.Void
+    public static @org.jetbrains.annotations.NotNull method equals-impl(p0: int, @org.jetbrains.annotations.Nullable p1: java.lang.Object): java.lang.Void
+    public final static method equals-impl0(p0: int, p1: int): boolean
+    public final method getValue(): int
+    public method hashCode(): int
+    public static method hashCode-impl(p0: int): int
+    public method toString(): java.lang.String
+    public static method toString-impl(p0: int): java.lang.String
+    public synthetic final method unbox-impl(): int
+}
+
+@kotlin.Metadata
+public final class InlineClassEqualsOverrideKt {
+    // source: 'inlineClassEqualsOverride.kt'
+    public final static @org.jetbrains.annotations.NotNull method box(): java.lang.String
+}