JVM_IR: do not handle Nothing in suspend tail call bridges

Else they wouldn't be tail call, would they?

compiler/fir/fir2ir/tests/org/jetbrains/kotlin/codegen/ir/FirBlackBoxCodegenTestGenerated.java

@@ -6706,6 +6706,11 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTestWithPackageReplacement("compiler/testData/codegen/box/coroutines/suspensionInsideSafeCall.kt", "kotlin.coroutines");
         }
 
+        @TestMetadata("tailCallToNothing.kt")
+        public void testTailCallToNothing() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/tailCallToNothing.kt");
+        }
+
         @TestMetadata("tryCatchFinallyWithHandleResult.kt")
         public void testTryCatchFinallyWithHandleResult_1_3() throws Exception {
             runTestWithPackageReplacement("compiler/testData/codegen/box/coroutines/tryCatchFinallyWithHandleResult.kt", "kotlin.coroutines");

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/KotlinNothingValueExceptionLowering.kt

@@ -19,11 +19,13 @@ import org.jetbrains.kotlin.ir.types.isNothing
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
 
-class KotlinNothingValueExceptionLowering(val backendContext: CommonBackendContext) : BodyLoweringPass {
+class KotlinNothingValueExceptionLowering(
+    val backendContext: CommonBackendContext, val skip: (IrDeclaration) -> Boolean = { false }
+) : BodyLoweringPass {
     override fun lower(irBody: IrBody, container: IrDeclaration) {
-        irBody.transformChildrenVoid(
+        if (!skip(container)) {
-            Transformer((container as IrSymbolDeclaration<*>).symbol)
+            irBody.transformChildrenVoid(Transformer((container as IrSymbolDeclaration<*>).symbol))
-        )
+        }
     }
 
     private inner class Transformer(val parent: IrSymbol) : IrElementTransformerVoid() {

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

@@ -11,6 +11,7 @@ import org.jetbrains.kotlin.backend.common.lower.*
 import org.jetbrains.kotlin.backend.common.lower.loops.forLoopsPhase
 import org.jetbrains.kotlin.backend.common.lower.optimizations.foldConstantLoweringPhase
 import org.jetbrains.kotlin.backend.common.phaser.*
+import org.jetbrains.kotlin.backend.jvm.codegen.shouldContainSuspendMarkers
 import org.jetbrains.kotlin.backend.jvm.lower.*
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.descriptors.Visibility
@@ -262,8 +263,8 @@ private val tailrecPhase = makeIrFilePhase(
     description = "Handle tailrec calls"
 )
 
-private val kotlinNothingValueExceptionPhase = makeIrFilePhase(
+private val kotlinNothingValueExceptionPhase = makeIrFilePhase<CommonBackendContext>(
-    ::KotlinNothingValueExceptionLowering,
+    { context -> KotlinNothingValueExceptionLowering(context) { it is IrFunction && !it.shouldContainSuspendMarkers() } },
     name = "KotlinNothingValueException",
     description = "Throw proper exception for calls returning value of type 'kotlin.Nothing'"
 )

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ExpressionCodegen.kt

@@ -449,12 +449,9 @@ class ExpressionCodegen(
         }
 
         return when {
-            expression.type.isNothing() -> {
-                unitValue
-            }
             expression is IrConstructorCall ->
                 MaterialValue(this, asmType, expression.type)
-            expression.type.isUnit() && irFunction.shouldContainSuspendMarkers() -> {
+            (expression.type.isNothing() || expression.type.isUnit()) && irFunction.shouldContainSuspendMarkers() -> {
                 // NewInference allows casting `() -> T` to `() -> Unit`. A CHECKCAST here will fail.
                 // Also, if the callee is a suspend function with a suspending tail call, the next `resumeWith`
                 // will continue from here, but the value passed to it might not have been `Unit`. An exception

compiler/testData/codegen/box/coroutines/tailCallToNothing.kt

@@ -0,0 +1,34 @@
+// IGNORE_BACKEND_FIR: JVM_IR
+// WITH_RUNTIME
+// WITH_COROUTINES
+import helpers.*
+import kotlin.coroutines.*
+import kotlin.coroutines.intrinsics.*
+
+suspend fun suspendThenThrow(): Nothing {
+    suspendCoroutineUninterceptedOrReturn<Unit> {
+        it.resume(Unit)
+        COROUTINE_SUSPENDED
+    }
+    throw RuntimeException()
+}
+
+suspend fun foo(x: Int = 1): Nothing = suspendThenThrow()
+
+interface I {
+    suspend fun bar(): Nothing
+}
+
+class C : I by (object : I {
+    override suspend fun bar(): Nothing = suspendThenThrow()
+})
+
+var result = ""
+
+fun box(): String {
+    suspend {
+        try { foo() } catch (e: RuntimeException) { result += "O" }
+        try { C().bar() } catch (e: RuntimeException) { result += "K" }
+    }.startCoroutine(EmptyContinuation)
+    return result
+}

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -7136,6 +7136,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTestWithPackageReplacement("compiler/testData/codegen/box/coroutines/suspensionInsideSafeCall.kt", "kotlin.coroutines");
         }
 
+        @TestMetadata("tailCallToNothing.kt")
+        public void testTailCallToNothing() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/tailCallToNothing.kt");
+        }
+
         @TestMetadata("tryCatchFinallyWithHandleResult.kt")
         public void testTryCatchFinallyWithHandleResult_1_2() throws Exception {
             runTestWithPackageReplacement("compiler/testData/codegen/box/coroutines/tryCatchFinallyWithHandleResult.kt", "kotlin.coroutines.experimental");

compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -7136,6 +7136,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTestWithPackageReplacement("compiler/testData/codegen/box/coroutines/suspensionInsideSafeCall.kt", "kotlin.coroutines");
         }
 
+        @TestMetadata("tailCallToNothing.kt")
+        public void testTailCallToNothing() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/tailCallToNothing.kt");
+        }
+
         @TestMetadata("tryCatchFinallyWithHandleResult.kt")
         public void testTryCatchFinallyWithHandleResult_1_2() throws Exception {
             runTestWithPackageReplacement("compiler/testData/codegen/box/coroutines/tryCatchFinallyWithHandleResult.kt", "kotlin.coroutines.experimental");

compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -6706,6 +6706,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTestWithPackageReplacement("compiler/testData/codegen/box/coroutines/suspensionInsideSafeCall.kt", "kotlin.coroutines");
         }
 
+        @TestMetadata("tailCallToNothing.kt")
+        public void testTailCallToNothing() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/tailCallToNothing.kt");
+        }
+
         @TestMetadata("tryCatchFinallyWithHandleResult.kt")
         public void testTryCatchFinallyWithHandleResult_1_3() throws Exception {
             runTestWithPackageReplacement("compiler/testData/codegen/box/coroutines/tryCatchFinallyWithHandleResult.kt", "kotlin.coroutines");

js/js.tests/test/org/jetbrains/kotlin/js/test/ir/semantics/IrJsCodegenBoxTestGenerated.java

@@ -5656,6 +5656,11 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
             runTestWithPackageReplacement("compiler/testData/codegen/box/coroutines/suspensionInsideSafeCall.kt", "kotlin.coroutines");
         }
 
+        @TestMetadata("tailCallToNothing.kt")
+        public void testTailCallToNothing() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/tailCallToNothing.kt");
+        }
+
         @TestMetadata("tryCatchFinallyWithHandleResult.kt")
         public void testTryCatchFinallyWithHandleResult_1_3() throws Exception {
             runTestWithPackageReplacement("compiler/testData/codegen/box/coroutines/tryCatchFinallyWithHandleResult.kt", "kotlin.coroutines");

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -5656,6 +5656,11 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             runTestWithPackageReplacement("compiler/testData/codegen/box/coroutines/suspensionInsideSafeCall.kt", "kotlin.coroutines");
         }
 
+        @TestMetadata("tailCallToNothing.kt")
+        public void testTailCallToNothing() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/tailCallToNothing.kt");
+        }
+
         @TestMetadata("tryCatchFinallyWithHandleResult.kt")
         public void testTryCatchFinallyWithHandleResult_1_3() throws Exception {
             runTestWithPackageReplacement("compiler/testData/codegen/box/coroutines/tryCatchFinallyWithHandleResult.kt", "kotlin.coroutines");