Filter out $suspendImpl functions from dumps (#271)

* Enable default interface methods generation
* Filter out $suspendImpl methods.

Closes #270

build.gradle.kts

@@ -109,6 +109,7 @@ kotlin {
 tasks.compileTestKotlin {
     compilerOptions {
         languageVersion.set(KotlinVersion.KOTLIN_1_9)
+        freeCompilerArgs.add("-Xjvm-default=all-compatibility")
     }
 }
 

src/main/kotlin/api/KotlinMetadataSignature.kt

@@ -60,6 +60,7 @@ internal data class MethodBinarySignature(
         super.isEffectivelyPublic(classAccess, classVisibility)
                 && !isAccessOrAnnotationsMethod()
                 && !isDummyDefaultConstructor()
+                && !isSuspendImplMethod()
 
     override fun findMemberVisibility(classVisibility: ClassVisibility?): MemberVisibility? {
         return super.findMemberVisibility(classVisibility)
@@ -71,6 +72,14 @@ internal data class MethodBinarySignature(
 
     private fun isDummyDefaultConstructor() =
         access.isSynthetic && name == "<init>" && desc == "(Lkotlin/jvm/internal/DefaultConstructorMarker;)V"
+
+    /**
+     * Kotlin compiler emits special `<originalFunctionName>$suspendImpl` methods for open
+     * suspendable functions. These synthetic functions could only be invoked from original function,
+     * or from a corresponding continuation. They don't constitute class's public ABI, but in some cases
+     * they might be declared public (namely, in case of default interface methods).
+     */
+    private fun isSuspendImplMethod() = access.isSynthetic && name.endsWith("\$suspendImpl")
 }
 
 /**

src/test/kotlin/cases/default/default.txt

@@ -7,7 +7,9 @@ public class cases/default/ClassFunctions {
 
 public abstract interface class cases/default/InterfaceFunctions {
 	public abstract fun withAllDefaults (ILjava/lang/String;)V
+	public static synthetic fun withAllDefaults$default (Lcases/default/InterfaceFunctions;ILjava/lang/String;ILjava/lang/Object;)V
 	public abstract fun withSomeDefaults (ILjava/lang/String;)V
+	public static synthetic fun withSomeDefaults$default (Lcases/default/InterfaceFunctions;ILjava/lang/String;ILjava/lang/Object;)V
 }
 
 public final class cases/default/InterfaceFunctions$DefaultImpls {

src/test/kotlin/cases/interfaces/interfaces.txt

@@ -1,13 +1,13 @@
 public abstract interface class cases/interfaces/BaseWithImpl {
-	public abstract fun foo ()I
+	public fun foo ()I
 }
 
 public final class cases/interfaces/BaseWithImpl$DefaultImpls {
 	public static fun foo (Lcases/interfaces/BaseWithImpl;)I
 }
 
 public abstract interface class cases/interfaces/DerivedWithImpl : cases/interfaces/BaseWithImpl {
-	public abstract fun foo ()I
+	public fun foo ()I
 }
 
 public final class cases/interfaces/DerivedWithImpl$DefaultImpls {

src/test/kotlin/cases/suspend/suspend.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2016-2024 JetBrains s.r.o.
+ * Use of this source code is governed by the Apache 2.0 License that can be found in the LICENSE.txt file.
+ */
+
+package cases.suspend
+
+public interface I {
+    suspend fun openFunction(): Int = 42
+}
+
+public interface II : I {
+    override suspend fun openFunction(): Int {
+        return super.openFunction() + 1
+    }
+}
+
+public open class C : II {
+    override suspend fun openFunction(): Int {
+        return super.openFunction() + 2
+    }
+}

src/test/kotlin/cases/suspend/suspend.txt

@@ -0,0 +1,21 @@
+public class cases/suspend/C : cases/suspend/II {
+	public fun <init> ()V
+	public fun openFunction (Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+}
+
+public abstract interface class cases/suspend/I {
+	public fun openFunction (Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+}
+
+public final class cases/suspend/I$DefaultImpls {
+	public static fun openFunction (Lcases/suspend/I;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+}
+
+public abstract interface class cases/suspend/II : cases/suspend/I {
+	public fun openFunction (Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+}
+
+public final class cases/suspend/II$DefaultImpls {
+	public static fun openFunction (Lcases/suspend/II;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+}
+

src/test/kotlin/tests/CasesPublicAPITest.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2020 JetBrains s.r.o.
+ * Copyright 2016-2024 JetBrains s.r.o.
  * Use of this source code is governed by the Apache 2.0 License that can be found in the LICENSE.txt file.
  */
 
@@ -58,6 +58,8 @@ class CasesPublicAPITest {
 
     @Test fun special() { snapshotAPIAndCompare(testName.methodName) }
 
+    @Test fun suspend() { snapshotAPIAndCompare(testName.methodName) }
+
     @Test fun whenMappings() { snapshotAPIAndCompare(testName.methodName) }
 
     @Test fun enums() { snapshotAPIAndCompare(testName.methodName) }