Do not filter out synthetic constructors that contain values of defau…

…lt arguments in Kotlin (#888)

org.jacoco.core.test.validation.kotlin/src/org/jacoco/core/test/validation/kotlin/targets/KotlinDefaultArgumentsTarget.kt

@@ -27,6 +27,10 @@ object KotlinDefaultArgumentsTarget {
         }
     }
 
+    class Constructor() {
+        constructor(a: Boolean, b: String = if (a) "a" else "b") : this() // assertFullyCovered(0, 2)
+    }
+
     @JvmStatic
     fun main(args: Array<String>) {
         f(a = "a")
@@ -38,6 +42,9 @@ object KotlinDefaultArgumentsTarget {
         branch(true)
 
         Open().f()
+
+        Constructor(false)
+        Constructor(true)
     }
 
 }

org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/KotlinDefaultArgumentsFilterTest.java

@@ -150,4 +150,38 @@ public void should_filter_open_functions() {
 				new Range(m.instructions.get(11), m.instructions.get(11)));
 	}
 
+	/**
+	 * <pre>
+	 * class C(a: Int = 42)
+	 * </pre>
+	 */
+	@Test
+	public void should_filter_constructors() {
+		final MethodNode m = new MethodNode(InstrSupport.ASM_API_VERSION,
+				Opcodes.ACC_SYNTHETIC, "<init>",
+				"(IILkotlin/jvm/internal/DefaultConstructorMarker;)V", null,
+				null);
+		context.classAnnotations
+				.add(KotlinGeneratedFilter.KOTLIN_METADATA_DESC);
+
+		m.visitVarInsn(Opcodes.ILOAD, 2);
+		m.visitInsn(Opcodes.ICONST_1);
+		m.visitInsn(Opcodes.IAND);
+		Label label = new Label();
+		m.visitJumpInsn(Opcodes.IFEQ, label);
+		// default argument
+		m.visitLdcInsn(Integer.valueOf(42));
+		m.visitVarInsn(Opcodes.ISTORE, 1);
+		m.visitLabel(label);
+		m.visitVarInsn(Opcodes.ALOAD, 0);
+		m.visitVarInsn(Opcodes.ILOAD, 1);
+		m.visitMethodInsn(Opcodes.INVOKESPECIAL, "Owner", "<init>", "(I)V",
+				false);
+		m.visitInsn(Opcodes.RETURN);
+
+		filter.filter(m, context, output);
+
+		assertIgnored(new Range(m.instructions.get(3), m.instructions.get(3)));
+	}
+
 }

org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/SyntheticFilterTest.java

@@ -82,6 +82,21 @@ public void should_filter_synthetic_method_with_suffix_default_in_non_kotlin_cla
 		assertMethodIgnored(m);
 	}
 
+	@Test
+	public void should_not_filter_synthetic_constructor_containing_default_arguments_in_kotlin_classes() {
+		final MethodNode m = new MethodNode(InstrSupport.ASM_API_VERSION,
+				Opcodes.ACC_SYNTHETIC, "<init>",
+				"(IILkotlin/jvm/internal/DefaultConstructorMarker;)V", null,
+				null);
+		context.classAnnotations
+				.add(KotlinGeneratedFilter.KOTLIN_METADATA_DESC);
+		m.visitInsn(Opcodes.NOP);
+
+		filter.filter(m, context, output);
+
+		assertIgnored();
+	}
+
 	@Test
 	public void should_not_filter_synthetic_methods_whose_last_argument_is_kotlin_coroutine_continuation() {
 		final MethodNode m = new MethodNode(InstrSupport.ASM_API_VERSION,

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

@@ -38,34 +38,49 @@
  * </pre>
  * 
  * Where <code>maskVar</code> is penultimate argument of synthetic method with
- * suffix "$default". And its value can't be zero - invocation with all
- * arguments uses original non synthetic method, thus <code>IFEQ</code>
- * instructions should be ignored.
+ * suffix "$default" or of synthetic constructor with last argument
+ * "kotlin.jvm.internal.DefaultConstructorMarker". And its value can't be zero -
+ * invocation with all arguments uses original non synthetic method, thus
+ * <code>IFEQ</code> instructions should be ignored.
  */
 public final class KotlinDefaultArgumentsFilter implements IFilter {
 
-	static boolean isDefaultArgumentsMethodName(final String methodName) {
-		return methodName.endsWith("$default");
+	static boolean isDefaultArgumentsMethod(final MethodNode methodNode) {
+		return methodNode.name.endsWith("$default");
+	}
+
+	static boolean isDefaultArgumentsConstructor(final MethodNode methodNode) {
+		if (!"<init>".equals(methodNode.name)) {
+			return false;
+		}
+		final Type[] argumentTypes = Type.getMethodType(methodNode.desc)
+				.getArgumentTypes();
+		if (argumentTypes.length < 2) {
+			return false;
+		}
+		return "kotlin.jvm.internal.DefaultConstructorMarker"
+				.equals(argumentTypes[argumentTypes.length - 1].getClassName());
 	}
 
 	public void filter(final MethodNode methodNode,
 			final IFilterContext context, final IFilterOutput output) {
 		if ((methodNode.access & Opcodes.ACC_SYNTHETIC) == 0) {
 			return;
 		}
-		if (!isDefaultArgumentsMethodName(methodNode.name)) {
-			return;
-		}
 		if (!KotlinGeneratedFilter.isKotlinClass(context)) {
 			return;
 		}
 
-		new Matcher().match(methodNode, output);
+		if (isDefaultArgumentsMethod(methodNode)) {
+			new Matcher().match(methodNode, output, false);
+		} else if (isDefaultArgumentsConstructor(methodNode)) {
+			new Matcher().match(methodNode, output, true);
+		}
 	}
 
 	private static class Matcher extends AbstractMatcher {
 		public void match(final MethodNode methodNode,
-				final IFilterOutput output) {
+				final IFilterOutput output, final boolean constructor) {
 			cursor = methodNode.instructions.getFirst();
 
 			nextIs(Opcodes.IFNULL);
@@ -91,7 +106,7 @@ public void match(final MethodNode methodNode,
 
 			final Set<AbstractInsnNode> ignore = new HashSet<AbstractInsnNode>();
 			final int maskVar = Type.getMethodType(methodNode.desc)
-					.getArgumentTypes().length - 2;
+					.getArgumentTypes().length - (constructor ? 1 : 2);
 			while (true) {
 				if (cursor.getOpcode() != Opcodes.ILOAD) {
 					break;

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

@@ -31,7 +31,12 @@ public void filter(final MethodNode methodNode,
 
 		if (KotlinGeneratedFilter.isKotlinClass(context)) {
 			if (KotlinDefaultArgumentsFilter
-					.isDefaultArgumentsMethodName(methodNode.name)) {
+					.isDefaultArgumentsMethod(methodNode)) {
+				return;
+			}
+
+			if (KotlinDefaultArgumentsFilter
+					.isDefaultArgumentsConstructor(methodNode)) {
 				return;
 			}
 

org.jacoco.doc/docroot/doc/changes.html

@@ -27,6 +27,13 @@ <h3>New Features</h3>
       (GitHub <a href="https://github.com/jacoco/jacoco/issues/887">#887</a>).</li>
 </ul>
 
+<h3>Fixed bugs</h3>
+<ul>
+  <li><code>synthetic</code> constructors that contain values of default arguments
+      in Kotlin should not be ignored
+      (GitHub <a href="https://github.com/jacoco/jacoco/issues/888">#888</a>).</li>
+</ul>
+
 <h2>Release 0.8.4 (2019/05/08)</h2>
 
 <h3>New Features</h3>