KotlinDefaultArgumentsFilter should not assume that all parameters consume one slot

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

@@ -19,6 +19,9 @@ object KotlinDefaultArgumentsTarget {
     private fun f(a: String = "a", b: String = "b") { // assertFullyCovered(0, 0)
     }
 
+    private fun longParameter(x: Long = 0) { // assertFullyCovered()
+    }
+
     private fun branch(a: Boolean, b: String = if (a) "a" else "b") { // assertFullyCovered(0, 2)
     }
 
@@ -38,6 +41,9 @@ object KotlinDefaultArgumentsTarget {
         /* next invocation doesn't use synthetic method: */
         f("a", "b")
 
+        longParameter()
+        longParameter(1)
+
         branch(false)
         branch(true)
 

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

@@ -184,4 +184,38 @@ public void should_filter_constructors() {
 		assertIgnored(new Range(m.instructions.get(3), m.instructions.get(3)));
 	}
 
+	/**
+	 * <pre>
+	 * data class C(val x: Long = 42)
+	 * </pre>
+	 */
+	@Test
+	public void should_filter_methods_with_parameters_that_consume_two_slots() {
+		final MethodNode m = new MethodNode(InstrSupport.ASM_API_VERSION,
+				Opcodes.ACC_SYNTHETIC, "<init>",
+				"(JILkotlin/jvm/internal/DefaultConstructorMarker;)V", null,
+				null);
+		context.classAnnotations
+				.add(KotlinGeneratedFilter.KOTLIN_METADATA_DESC);
+
+		m.visitVarInsn(Opcodes.ILOAD, 3);
+		m.visitInsn(Opcodes.ICONST_1);
+		m.visitInsn(Opcodes.IAND);
+		final 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>", "(J)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/src/org/jacoco/core/internal/analysis/filter/KotlinDefaultArgumentsFilter.java

@@ -105,8 +105,7 @@ public void match(final MethodNode methodNode,
 			}
 
 			final Set<AbstractInsnNode> ignore = new HashSet<AbstractInsnNode>();
-			final int maskVar = Type.getMethodType(methodNode.desc)
-					.getArgumentTypes().length - (constructor ? 1 : 2);
+			final int maskVar = maskVar(methodNode.desc, constructor);
 			while (true) {
 				if (cursor.getOpcode() != Opcodes.ILOAD) {
 					break;
@@ -129,6 +128,22 @@ public void match(final MethodNode methodNode,
 				output.ignore(i, i);
 			}
 		}
+
+		private static int maskVar(final String desc,
+				final boolean constructor) {
+			int slot = 0;
+			if (constructor) {
+				// one slot for reference to current object
+				slot++;
+			}
+			final Type[] argumentTypes = Type.getMethodType(desc)
+					.getArgumentTypes();
+			final int penultimateArgument = argumentTypes.length - 2;
+			for (int i = 0; i < penultimateArgument; i++) {
+				slot += argumentTypes[i].getSize();
+			}
+			return slot;
+		}
 	}
 
 }

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

@@ -36,6 +36,10 @@ <h3>Fixed bugs</h3>
       (GitHub <a href="https://github.com/jacoco/jacoco/issues/888">#888</a>).</li>
   <li>Instrumentation should update indexes of local variables in annotations
       (GitHub <a href="https://github.com/jacoco/jacoco/issues/894">#894</a>).</li>
+  <li>Branches added by the Kotlin compiler for functions with default arguments
+      and containing arguments of type <code>long</code> or <code>double</code>
+      should be filtered out during generation of report
+      (GitHub <a href="https://github.com/jacoco/jacoco/issues/908">#908</a>).</li>
 </ul>
 
 <h2>Release 0.8.4 (2019/05/08)</h2>