KotlinCoroutineFilter should filter suspension points that return inline value classes #1871

Godin · 2025-04-04T22:37:09Z

Given src/Utils.kt

suspend fun suspendingFunction(): String = ""
suspend fun suspendingFunctionReturningInlineValueClass(): InlineValueClass = InlineValueClass("")
@JvmInline
value class InlineValueClass(val value: String)
fun beforeSuspensionPoint() = Any()
fun afterSuspensionPoint(a: Any, b: Any) = Unit

compilation of src/Example.kt

import kotlinx.coroutines.runBlocking
fun example() =
    runBlocking {
        afterSuspensionPoint(
            beforeSuspensionPoint(),
            suspendingFunction()
        )
    }

differs from compilation of src/Example.kt

import kotlinx.coroutines.runBlocking
fun example() =
    runBlocking {
        afterSuspensionPoint(
            beforeSuspensionPoint(),
            suspendingFunctionReturningInlineValueClass()
        )
    }

as

index 274d343..1df493e 100644
--- 1/1.txt
+++ 2/2.txt
@@ -66,7 +66,7 @@ final class ExampleKt$example$1 extends kotlin/coroutines/jvm/internal/SuspendLa
     ALOAD 0
     ICONST_1
     PUTFIELD ExampleKt$example$1.label : I
-    INVOKESTATIC UtilsKt.suspendingFunctionReturningInlineValueClass (Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+    INVOKESTATIC UtilsKt.suspendingFunction (Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
     DUP
     ALOAD 3
     IF_ACMPNE L7
@@ -82,15 +82,10 @@ final class ExampleKt$example$1 extends kotlin/coroutines/jvm/internal/SuspendLa
     ALOAD 1
     INVOKESTATIC kotlin/ResultKt.throwOnFailure (Ljava/lang/Object;)V
     ALOAD 1
-    CHECKCAST InlineValueClass
-    INVOKEVIRTUAL InlineValueClass.unbox-impl ()Ljava/lang/String;
    L7
-    LINENUMBER 7 L7
    FRAME FULL [ExampleKt$example$1 java/lang/Object java/lang/Object java/lang/Object] [java/lang/Object]
     ALOAD 2
     SWAP
-    CHECKCAST java/lang/String
-    INVOKESTATIC InlineValueClass.box-impl (Ljava/lang/String;)LInlineValueClass;
    L9
     LINENUMBER 5 L9
     INVOKESTATIC UtilsKt.afterSuspensionPoint (Ljava/lang/Object;Ljava/lang/Object;)V

and

jacoco/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/KotlinCoroutineFilter.java

Lines 130 to 135 in 78d5eff

    
           nextIs(Opcodes.ALOAD); 
        
           nextIsThrowOnFailure(); 
        
           nextIs(Opcodes.ALOAD); 
        
           if (cursor != null && skipNonOpcodes(cursor 
        
           		.getNext()) == continuationAfterLoadedResult) {

does not handle

    CHECKCAST InlineValueClass
    INVOKEVIRTUAL InlineValueClass.unbox-impl ()Ljava/lang/String;

JetBrains/kotlin@ccc5b7a

See #1868 (comment) and #1868 (comment)

leveretka

Looks good

leveretka · 2025-09-22T21:36:05Z

org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/KotlinCoroutineFilter.java

 				}
-
-				for (AbstractInsnNode j = i; j != null; j = j.getNext()) {
-					cursor = j;
-					nextIs(Opcodes.ALOAD);
-					nextIsThrowOnFailure();
-
-					nextIs(Opcodes.ALOAD);
-					if (cursor != null && skipNonOpcodes(cursor
-							.getNext()) == continuationAfterLoadedResult) {
-						ignore.add(i);
-						ignore.add(cursor);
-						suspensionPoint++;
-						break;
-					}
-				}


As discussed offline, the simplified logic here still detects desired generated code, so no need to have a very precise matcher here

Godin self-assigned this Apr 4, 2025

Godin added this to Filtering Apr 4, 2025

github-project-automation bot moved this to Awaiting triage in Filtering Apr 4, 2025

Godin moved this from Awaiting triage to In Progress in Filtering Apr 4, 2025

Godin added this to the 0.8.14 milestone Apr 4, 2025

Godin added component: core.filters language: Kotlin labels Apr 8, 2025

(WIP) add validation test

7caa090

Godin force-pushed the kotlin_suspending_function_returning_inline_value_class branch from 674fd39 to 7caa090 Compare September 19, 2025 19:05

(WIP) add unit test

e0ac08d

Godin changed the title ~~Improve KotlinCoroutineFilter~~ KotlinCoroutineFilter should filter suspension points that return inline value classes Sep 19, 2025

Godin added 2 commits September 19, 2025 21:24

(WIP) fix

9e13361

(WIP) update changelog

8aa9bf6

Godin marked this pull request as ready for review September 19, 2025 19:48

Godin requested a review from leveretka September 19, 2025 19:48

leveretka approved these changes Sep 22, 2025

View reviewed changes

Godin merged commit fd2b323 into jacoco:master Sep 22, 2025
36 checks passed

Godin deleted the kotlin_suspending_function_returning_inline_value_class branch September 22, 2025 21:39

github-project-automation bot moved this from In Progress to Done in Filtering Sep 22, 2025

Godin mentioned this pull request Sep 23, 2025

100% branch coverage cannot be met when the suspend method return value is kotlin.Result #1868

Closed

marcin-arciszewski-gds mentioned this pull request Oct 17, 2025

feat: upgrade jacoco to 0.8.14 govuk-one-login/mobile-android-pipelines#191

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KotlinCoroutineFilter should filter suspension points that return inline value classes #1871

KotlinCoroutineFilter should filter suspension points that return inline value classes #1871

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Godin commented Apr 4, 2025 •

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	nextIs(Opcodes.ALOAD);
	nextIsThrowOnFailure();

	nextIs(Opcodes.ALOAD);
	if (cursor != null && skipNonOpcodes(cursor
	.getNext()) == continuationAfterLoadedResult) {

KotlinCoroutineFilter should filter suspension points that return inline value classes #1871

KotlinCoroutineFilter should filter suspension points that return inline value classes #1871

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Godin commented Apr 4, 2025 •

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