JVM IR: Use inline SAM wrappers inside of inline lambdas

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

@@ -4324,6 +4324,11 @@ public class FirBytecodeTextTestGenerated extends AbstractFirBytecodeTextTest {
             runTest("compiler/testData/codegen/bytecodeText/sam/samWrapperForNullableInitialization.kt");
         }
 
+        @TestMetadata("samWrapperInInlineLambda.kt")
+        public void testSamWrapperInInlineLambda() throws Exception {
+            runTest("compiler/testData/codegen/bytecodeText/sam/samWrapperInInlineLambda.kt");
+        }
+
         @TestMetadata("samWrapperOfLambda.kt")
         public void testSamWrapperOfLambda() throws Exception {
             runTest("compiler/testData/codegen/bytecodeText/sam/samWrapperOfLambda.kt");

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

@@ -12,11 +12,13 @@ import org.jetbrains.kotlin.backend.jvm.JvmBackendContext
 import org.jetbrains.kotlin.backend.jvm.ir.erasedUpperBound
 import org.jetbrains.kotlin.descriptors.DescriptorVisibilities
 import org.jetbrains.kotlin.ir.declarations.IrDeclarationOrigin
+import org.jetbrains.kotlin.ir.declarations.IrFunction
 import org.jetbrains.kotlin.ir.expressions.IrTypeOperatorCall
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.types.getClass
 import org.jetbrains.kotlin.ir.util.defaultType
 import org.jetbrains.kotlin.load.java.JavaDescriptorVisibilities
+import org.jetbrains.kotlin.utils.addToStdlib.safeAs
 
 internal val singleAbstractMethodPhase = makeIrFilePhase(
     ::JvmSingleAbstractMethodLowering,
@@ -25,6 +27,15 @@ internal val singleAbstractMethodPhase = makeIrFilePhase(
 )
 
 private class JvmSingleAbstractMethodLowering(context: JvmBackendContext) : SingleAbstractMethodLowering(context) {
+    // The JVM BE produces inline SAM wrappers both in the scope of an inline function as well as in the scope
+    // of an inline lambda. Compare with `SamWrapperClasses.getSamWrapperClass`.
+    override val inInlineFunctionScope: Boolean
+        get() = allScopes.any { scope ->
+            scope.irElement.safeAs<IrFunction>()?.let {
+                it.isInline || it.origin == IrDeclarationOrigin.LOCAL_FUNCTION_FOR_LAMBDA
+            } ?: false
+        }
+
     override fun getWrapperVisibility(expression: IrTypeOperatorCall, scopes: List<ScopeWithIr>) =
         if (inInlineFunctionScope) DescriptorVisibilities.PUBLIC else JavaDescriptorVisibilities.PACKAGE_VISIBILITY
 

compiler/testData/codegen/bytecodeText/sam/samWrapperInInlineLambda.kt

@@ -0,0 +1,18 @@
+// FILE: J.java
+
+public class J {
+    public static void g(Runnable r) {
+        r.run();
+    }
+}
+
+// FILE: test.kt
+
+fun box(): String {
+    var result = "Fail"
+    val setter = { result = "OK" }
+    1.apply { J.g(setter) }
+    return result
+}
+
+// 1 INVOKESPECIAL TestKt\$sam\$i\$java_lang_Runnable\$0.<init> \(Lkotlin/jvm/functions/Function0;\)V

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

@@ -4396,6 +4396,11 @@ public class BytecodeTextTestGenerated extends AbstractBytecodeTextTest {
             runTest("compiler/testData/codegen/bytecodeText/sam/samWrapperForNullableInitialization.kt");
         }
 
+        @TestMetadata("samWrapperInInlineLambda.kt")
+        public void testSamWrapperInInlineLambda() throws Exception {
+            runTest("compiler/testData/codegen/bytecodeText/sam/samWrapperInInlineLambda.kt");
+        }
+
         @TestMetadata("samWrapperOfLambda.kt")
         public void testSamWrapperOfLambda() throws Exception {
             runTest("compiler/testData/codegen/bytecodeText/sam/samWrapperOfLambda.kt");

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

@@ -4324,6 +4324,11 @@ public class IrBytecodeTextTestGenerated extends AbstractIrBytecodeTextTest {
             runTest("compiler/testData/codegen/bytecodeText/sam/samWrapperForNullableInitialization.kt");
         }
 
+        @TestMetadata("samWrapperInInlineLambda.kt")
+        public void testSamWrapperInInlineLambda() throws Exception {
+            runTest("compiler/testData/codegen/bytecodeText/sam/samWrapperInInlineLambda.kt");
+        }
+
         @TestMetadata("samWrapperOfLambda.kt")
         public void testSamWrapperOfLambda() throws Exception {
             runTest("compiler/testData/codegen/bytecodeText/sam/samWrapperOfLambda.kt");