[JVM] Fix detection of $DefaultImpl bridges

Namely, we should:

1. Preserve `originalFunctionForDefaultImpl` attribute in
`AddContinuationLowering`

2. Take into account that call in the bridge body might be rerouted
to the synthetic accessor.

Otherwise, we may fail to detect $DefaultImpl bridge. In this case, we
generate excess state machine for the bridge and may end up with
incorrect bytecode.

^KT-79442: Fixed

(cherry picked from commit a5c4b54)

Author: grechkovlad

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLBlackBoxTestGenerated.java

@@ -294,6 +294,13 @@ internal class AddContinuationLowering(context: JvmBackendContext) : SuspendLowe
 
                 val capturesCrossinline = function.isCapturingCrossinline()
                 val view = function.suspendFunctionViewOrStub(context)
+
+                // if X is original for Y, then (view for X) is an original for the (view for Y)
+                function.originalFunctionForDefaultImpl?.let { originalForDefaultImplBridge ->
+                    val viewForOriginal = originalForDefaultImplBridge.suspendFunctionOriginal().viewOfOriginalSuspendFunction
+                    if (viewForOriginal != null) view.originalFunctionForDefaultImpl = viewForOriginal
+                }
+
                 val continuationParameter = view.continuationParameter()
                 val parameterMap = function.parameters.zip(view.parameters.filter { it != continuationParameter }).toMap()
                 view.body = function.moveBodyTo(view, parameterMap)

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLReversedBlackBoxTestGenerated.java

@@ -91,7 +91,7 @@ private fun IrFunction.isDefaultImplsBridgeInJvmDefaultEnableMode(): Boolean =
             (parent as? IrClass)?.origin == JvmLoweredDeclarationOrigin.DEFAULT_IMPLS &&
             // (Note that we could've checked this directly via `context.config.jvmDefaultMode`, but that would require passing `context`
             // to utilities in this file, and all their call sites.)
-            ((body as? IrExpressionBody)?.expression as? IrCall)?.symbol?.owner == originalFunctionForDefaultImpl
+            isBodyBridgeCallTo(originalFunctionForDefaultImpl)
 
 fun IrFunction.shouldContainSuspendMarkers(): Boolean = !isNonBoxingSuspendDelegation() &&
         // These functions also contain a single `suspend` tail call, but if it returns an unboxed inline class value,

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirLightTreeBlackBoxCodegenTestGenerated.java

@@ -529,3 +529,20 @@ fun IrClass.findEnumValuesFunction(context: JvmBackendContext): IrSimpleFunction
 val IrValueParameter.isSkippedInGenericSignature: Boolean
     get() = origin == JvmLoweredDeclarationOrigin.FIELD_FOR_OUTER_THIS ||
             origin == JvmLoweredDeclarationOrigin.ENUM_CONSTRUCTOR_SYNTHETIC_PARAMETER
+
+private fun IrFunction.singleCallOrNull(): IrCall? = when (body) {
+    is IrBlockBody -> {
+        val statements = (body as IrBlockBody).statements
+        (statements.singleOrNull() as? IrReturn)?.value as? IrCall
+    }
+    is IrExpressionBody -> {
+        val expression = (body as IrExpressionBody).expression
+        expression as? IrCall
+    }
+    else -> null
+}
+
+fun IrFunction.isBodyBridgeCallTo(target: IrSimpleFunction?): Boolean {
+    val callee: IrSimpleFunction = singleCallOrNull()?.symbol?.owner ?: return false
+    return callee == target || (callee.origin == IrDeclarationOrigin.SYNTHETIC_ACCESSOR && callee.isBodyBridgeCallTo(target))
+}

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirPsiBlackBoxCodegenTestGenerated.java

@@ -0,0 +1,42 @@
+// Corresponds to KT-79442
+
+// TARGET_BACKEND: JVM
+
+// WITH_STDLIB
+// WITH_COROUTINES
+// JVM_DEFAULT_MODE: enable
+
+// CHECK_BYTECODE_LISTING
+// CHECK_BYTECODE_TEXT
+
+import helpers.*
+import kotlin.coroutines.*
+
+interface Repository {
+    suspend fun get(): Result<String>
+    suspend fun local(): Result<String> = get()
+    suspend fun remote(): Result<String> = get()
+
+}
+
+fun box(): String {
+
+    var res = "Fail 1"
+
+    val x = object : Repository {
+        override suspend fun get(): Result<String> {
+            return Result.success("OK")
+        }
+    }
+
+    suspend {
+        res = x.local().getOrDefault("Fail 2")
+    }.startCoroutine(EmptyContinuation)
+
+    return res
+}
+
+// @Repository$DefaultImpls.class:
+// 0 @Lkotlin/coroutines/jvm/internal/DebugMetadata;
+// 0 L$0
+// 2 ALOAD 1

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

@@ -0,0 +1,90 @@
+@kotlin.coroutines.jvm.internal.DebugMetadata
+@kotlin.Metadata
+final class InterfaceWithTwoDefaultFunsReturnValueTypeKt$box$1 {
+    // source: 'interfaceWithTwoDefaultFunsReturnValueType.kt'
+    enclosing method InterfaceWithTwoDefaultFunsReturnValueTypeKt.box()Ljava/lang/String;
+    synthetic final field $res: kotlin.jvm.internal.Ref$ObjectRef
+    synthetic final field $x: InterfaceWithTwoDefaultFunsReturnValueTypeKt$box$x$1
+    field L$0: java.lang.Object
+    field label: int
+    inner (anonymous) class InterfaceWithTwoDefaultFunsReturnValueTypeKt$box$1
+    inner (anonymous) class InterfaceWithTwoDefaultFunsReturnValueTypeKt$box$x$1
+    method <init>(p0: kotlin.jvm.internal.Ref$ObjectRef, p1: InterfaceWithTwoDefaultFunsReturnValueTypeKt$box$x$1, p2: kotlin.coroutines.Continuation): void
+    public final method create(p0: kotlin.coroutines.Continuation): kotlin.coroutines.Continuation
+    public synthetic bridge method invoke(p0: java.lang.Object): java.lang.Object
+    public final method invoke(p0: kotlin.coroutines.Continuation): java.lang.Object
+    public final method invokeSuspend(p0: java.lang.Object): java.lang.Object
+    public final inner class kotlin/jvm/internal/Ref$ObjectRef
+}
+
+@kotlin.Metadata
+public final class InterfaceWithTwoDefaultFunsReturnValueTypeKt$box$x$1 {
+    // source: 'interfaceWithTwoDefaultFunsReturnValueType.kt'
+    enclosing method InterfaceWithTwoDefaultFunsReturnValueTypeKt.box()Ljava/lang/String;
+    inner (anonymous) class InterfaceWithTwoDefaultFunsReturnValueTypeKt$box$x$1
+    method <init>(): void
+    public method get-IoAF18A(p0: kotlin.coroutines.Continuation): java.lang.Object
+    public method local-IoAF18A(p0: kotlin.coroutines.Continuation): java.lang.Object
+    public method remote-IoAF18A(p0: kotlin.coroutines.Continuation): java.lang.Object
+    public final inner class kotlin/Result$Companion
+}
+
+@kotlin.Metadata
+public final class InterfaceWithTwoDefaultFunsReturnValueTypeKt {
+    // source: 'interfaceWithTwoDefaultFunsReturnValueType.kt'
+    inner (anonymous) class InterfaceWithTwoDefaultFunsReturnValueTypeKt$box$1
+    inner (anonymous) class InterfaceWithTwoDefaultFunsReturnValueTypeKt$box$x$1
+    public final static @org.jetbrains.annotations.NotNull method box(): java.lang.String
+    public final inner class kotlin/jvm/internal/Ref$ObjectRef
+}
+
+@kotlin.Metadata
+public final class Repository$DefaultImpls {
+    // source: 'interfaceWithTwoDefaultFunsReturnValueType.kt'
+    public deprecated static @java.lang.Deprecated @org.jetbrains.annotations.Nullable method local-IoAF18A(@org.jetbrains.annotations.NotNull p0: Repository, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.Continuation): java.lang.Object
+    public deprecated static @java.lang.Deprecated @org.jetbrains.annotations.Nullable method remote-IoAF18A(@org.jetbrains.annotations.NotNull p0: Repository, @org.jetbrains.annotations.NotNull p1: kotlin.coroutines.Continuation): java.lang.Object
+    public final inner class Repository$DefaultImpls
+}
+
+@kotlin.coroutines.jvm.internal.DebugMetadata
+@kotlin.Metadata
+final class Repository$local$1 {
+    // source: 'interfaceWithTwoDefaultFunsReturnValueType.kt'
+    enclosing method Repository.local-IoAF18A$suspendImpl(LRepository;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+    field L$0: java.lang.Object
+    field label: int
+    synthetic field result: java.lang.Object
+    synthetic final field this$0: Repository
+    inner (anonymous) class Repository$local$1
+    method <init>(p0: Repository, p1: kotlin.coroutines.Continuation): void
+    public final @org.jetbrains.annotations.Nullable method invokeSuspend(@org.jetbrains.annotations.NotNull p0: java.lang.Object): java.lang.Object
+}
+
+@kotlin.coroutines.jvm.internal.DebugMetadata
+@kotlin.Metadata
+final class Repository$remote$1 {
+    // source: 'interfaceWithTwoDefaultFunsReturnValueType.kt'
+    enclosing method Repository.remote-IoAF18A$suspendImpl(LRepository;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+    field L$0: java.lang.Object
+    field label: int
+    synthetic field result: java.lang.Object
+    synthetic final field this$0: Repository
+    inner (anonymous) class Repository$remote$1
+    method <init>(p0: Repository, p1: kotlin.coroutines.Continuation): void
+    public final @org.jetbrains.annotations.Nullable method invokeSuspend(@org.jetbrains.annotations.NotNull p0: java.lang.Object): java.lang.Object
+}
+
+@kotlin.Metadata
+public interface Repository {
+    // source: 'interfaceWithTwoDefaultFunsReturnValueType.kt'
+    inner (anonymous) class Repository$local$1
+    inner (anonymous) class Repository$remote$1
+    public synthetic static method access$local-IoAF18A$jd(p0: Repository, p1: kotlin.coroutines.Continuation): java.lang.Object
+    public synthetic static method access$remote-IoAF18A$jd(p0: Repository, p1: kotlin.coroutines.Continuation): java.lang.Object
+    public abstract @org.jetbrains.annotations.Nullable method get-IoAF18A(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.Continuation): java.lang.Object
+    public synthetic static method local-IoAF18A$suspendImpl(p0: Repository, p1: kotlin.coroutines.Continuation): java.lang.Object
+    public @org.jetbrains.annotations.Nullable method local-IoAF18A(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.Continuation): java.lang.Object
+    public synthetic static method remote-IoAF18A$suspendImpl(p0: Repository, p1: kotlin.coroutines.Continuation): java.lang.Object
+    public @org.jetbrains.annotations.Nullable method remote-IoAF18A(@org.jetbrains.annotations.NotNull p0: kotlin.coroutines.Continuation): java.lang.Object
+    public final inner class Repository$DefaultImpls
+}