Add filter for bytecode that ECJ generates for String in switch (#735)

11 files changed, 350 insertions, 37 deletions

diff --git a/org.jacoco.core.test.validation.java7/src/org/jacoco/core/test/validation/java7/StringSwitchTest.java b/org.jacoco.core.test.validation.java7/src/org/jacoco/core/test/validation/java7/StringSwitchTest.java
index 242a55f5..0a40c010 100644
--- a/org.jacoco.core.test.validation.java7/src/org/jacoco/core/test/validation/java7/StringSwitchTest.java
+++ b/org.jacoco.core.test.validation.java7/src/org/jacoco/core/test/validation/java7/StringSwitchTest.java
@@ -11,7 +11,6 @@
  *******************************************************************************/
 package org.jacoco.core.test.validation.java7;
 
-import org.jacoco.core.test.validation.Source.Line;
 import org.jacoco.core.test.validation.ValidationTestBase;
 import org.jacoco.core.test.validation.java7.targets.StringSwitchTarget;
 
@@ -25,31 +24,4 @@ public class StringSwitchTest extends ValidationTestBase {
 		super(StringSwitchTarget.class);
 	}
 
-	public void assertSwitchCovered(final Line line) {
-		if (isJDKCompiler) {
-			assertFullyCovered(line, 0, 4);
-		} else {
-			// Filtering for ECJ not yet implemented:
-			assertPartlyCovered(line, 2, 7);
-		}
-	}
-
-	public void assertSwitchNotCovered(final Line line) {
-		if (isJDKCompiler) {
-			assertNotCovered(line, 4, 0);
-		} else {
-			// Filtering for ECJ not yet implemented:
-			assertNotCovered(line, 9, 0);
-		}
-	}
-
-	public void assertLookupswitch(final Line line) {
-		if (isJDKCompiler) {
-			assertNotCovered(line, 3, 0);
-		} else {
-			// Filtering for ECJ not yet implemented:
-			assertNotCovered(line, 7, 0);
-		}
-	}
-
 }
diff --git a/org.jacoco.core.test.validation.java7/src/org/jacoco/core/test/validation/java7/targets/StringSwitchTarget.java b/org.jacoco.core.test.validation.java7/src/org/jacoco/core/test/validation/java7/targets/StringSwitchTarget.java
index 7b1bc291..db933f78 100644
--- a/org.jacoco.core.test.validation.java7/src/org/jacoco/core/test/validation/java7/targets/StringSwitchTarget.java
+++ b/org.jacoco.core.test.validation.java7/src/org/jacoco/core/test/validation/java7/targets/StringSwitchTarget.java
@@ -19,7 +19,7 @@ import static org.jacoco.core.test.validation.targets.Stubs.nop;
 public class StringSwitchTarget {
 
 	private static void covered(Object s) {
-		switch (String.valueOf(s)) { // assertSwitchCovered()
+		switch (String.valueOf(s)) { // assertFullyCovered(0, 4)
 		case "a":
 			nop("case a"); // assertFullyCovered()
 			break;
@@ -36,7 +36,7 @@ public class StringSwitchTarget {
 	}
 
 	private static void notCovered(Object s) {
-		switch (String.valueOf(s)) { // assertSwitchNotCovered()
+		switch (String.valueOf(s)) { // assertNotCovered(4, 0)
 		case "a":
 			nop("case a");
 			break;
@@ -88,7 +88,7 @@ public class StringSwitchTarget {
 	 * In this case javac generates <code>LOOKUPSWITCH</code> for second switch.
 	 */
 	private static void lookupswitch(Object s) {
-		switch (String.valueOf(s)) { // assertLookupswitch()
+		switch (String.valueOf(s)) { // assertNotCovered(3, 0)
 		case "a":
 			nop("case a");
 			break;
diff --git a/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/MethodAnalyzerTest.java b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/MethodAnalyzerTest.java
index 114ebb59..de3ec4d9 100644
--- a/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/MethodAnalyzerTest.java
+++ b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/MethodAnalyzerTest.java
@@ -14,6 +14,9 @@ package org.jacoco.core.internal.analysis;
 import static org.junit.Assert.assertEquals;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
 
 import org.jacoco.core.analysis.ILine;
 import org.jacoco.core.analysis.IMethodCoverage;
@@ -449,7 +452,7 @@ public class MethodAnalyzerTest implements IProbeIdGenerator {
 		assertLine(1002, 0, 1, 0, 0);
 	}
 
-	// === Scenario: table switch ===
+	// === Scenario: table switch with and without replace filtering ===
 
 	private void createTableSwitch() {
 		final Label l0 = new Label();
@@ -494,6 +497,41 @@ public class MethodAnalyzerTest implements IProbeIdGenerator {
 		assertEquals(4, nextProbeId);
 	}
 
+	private static final IFilter SWITCH_FILTER = new IFilter() {
+		public void filter(final MethodNode methodNode,
+				final IFilterContext context, final IFilterOutput output) {
+			final AbstractInsnNode i = methodNode.instructions.get(3);
+			assertEquals(Opcodes.TABLESWITCH, i.getOpcode());
+			final AbstractInsnNode t1 = methodNode.instructions.get(6);
+			assertEquals(Opcodes.BIPUSH, t1.getOpcode());
+			final AbstractInsnNode t2 = methodNode.instructions.get(13);
+			assertEquals(Opcodes.BIPUSH, t2.getOpcode());
+
+			final Set<AbstractInsnNode> newTargets = new HashSet<AbstractInsnNode>();
+			newTargets.add(t1);
+			newTargets.add(t2);
+			output.replaceBranches(i, newTargets);
+		}
+	};
+
+	@Test
+	public void table_switch_with_filter_should_show_2_branches_when_original_replaced() {
+		createTableSwitch();
+		runMethodAnalzer(SWITCH_FILTER);
+
+		assertLine(1001, 2, 0, 2, 0);
+	}
+
+	@Test
+	public void table_switch_with_filter_should_show_full_branch_coverage_when_new_targets_covered() {
+		createTableSwitch();
+		probes[0] = true;
+		probes[1] = true;
+		runMethodAnalzer(SWITCH_FILTER);
+
+		assertLine(1001, 0, 2, 0, 2);
+	}
+
 	@Test
 	public void table_switch_should_show_missed_when_no_probes_are_executed() {
 		createTableSwitch();
diff --git a/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/FilterTestBase.java b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/FilterTestBase.java
index 50bb59f3..12064123 100644
--- a/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/FilterTestBase.java
+++ b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/FilterTestBase.java
@@ -16,6 +16,7 @@ import static org.junit.Assert.fail;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
 
 import org.objectweb.asm.tree.AbstractInsnNode;
 import org.objectweb.asm.tree.MethodNode;
@@ -42,6 +43,11 @@ public abstract class FilterTestBase {
 				final AbstractInsnNode i2) {
 			fail();
 		}
+
+		public void replaceBranches(final AbstractInsnNode source,
+				final Set<AbstractInsnNode> newTargets) {
+			fail();
+		}
 	};
 
 	final void assertIgnored(Range... ranges) {
diff --git a/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/FinallyFilterTest.java b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/FinallyFilterTest.java
index 987f3398..843790ec 100644
--- a/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/FinallyFilterTest.java
+++ b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/FinallyFilterTest.java
@@ -421,4 +421,9 @@ public class FinallyFilterTest implements IFilterOutput {
 		}
 	}
 
+	public void replaceBranches(final AbstractInsnNode source,
+			final Set<AbstractInsnNode> newTargets) {
+		fail();
+	}
+
 }
diff --git a/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/StringSwitchEcjFilterTest.java b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/StringSwitchEcjFilterTest.java
new file mode 100644
index 00000000..e1bfcb82
--- /dev/null
+++ b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/filter/StringSwitchEcjFilterTest.java
@@ -0,0 +1,141 @@
+/*******************************************************************************
+ * Copyright (c) 2009, 2018 Mountainminds GmbH & Co. KG and Contributors
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Evgeny Mandrikov - initial API and implementation
+ *
+ *******************************************************************************/
+package org.jacoco.core.internal.analysis.filter;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.fail;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import org.jacoco.core.internal.instr.InstrSupport;
+import org.junit.Test;
+import org.objectweb.asm.Label;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.tree.AbstractInsnNode;
+import org.objectweb.asm.tree.MethodNode;
+
+/**
+ * Unit tests for {@link StringSwitchEcjFilter}.
+ */
+public class StringSwitchEcjFilterTest {
+
+	private final IFilter filter = new StringSwitchEcjFilter();
+
+	private final FilterContextMock context = new FilterContextMock();
+
+	private AbstractInsnNode fromInclusive;
+	private AbstractInsnNode toInclusive;
+
+	private AbstractInsnNode source;
+	private Set<AbstractInsnNode> newTargets;
+
+	private final IFilterOutput output = new IFilterOutput() {
+		public void ignore(final AbstractInsnNode fromInclusive,
+				final AbstractInsnNode toInclusive) {
+			assertNull(StringSwitchEcjFilterTest.this.fromInclusive);
+			StringSwitchEcjFilterTest.this.fromInclusive = fromInclusive;
+			StringSwitchEcjFilterTest.this.toInclusive = toInclusive;
+		}
+
+		public void merge(final AbstractInsnNode i1,
+				final AbstractInsnNode i2) {
+			fail();
+		}
+
+		public void replaceBranches(final AbstractInsnNode source,
+				final Set<AbstractInsnNode> newTargets) {
+			assertNull(StringSwitchEcjFilterTest.this.source);
+			StringSwitchEcjFilterTest.this.source = source;
+			StringSwitchEcjFilterTest.this.newTargets = newTargets;
+		}
+	};
+
+	@Test
+	public void should_filter() {
+		final Set<AbstractInsnNode> expectedNewTargets = new HashSet<AbstractInsnNode>();
+
+		final MethodNode m = new MethodNode(InstrSupport.ASM_API_VERSION, 0,
+				"name", "()V", null, null);
+
+		final Label case1 = new Label();
+		final Label case2 = new Label();
+		final Label case3 = new Label();
+		final Label caseDefault = new Label();
+		final Label h1 = new Label();
+		final Label h2 = new Label();
+
+		m.visitVarInsn(Opcodes.ALOAD, 1);
+
+		m.visitVarInsn(Opcodes.ASTORE, 2);
+		m.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/String", "hashCode",
+				"()I", false);
+		m.visitTableSwitchInsn(97, 98, caseDefault, h1, h2);
+
+		m.visitLabel(h1);
+		final AbstractInsnNode expectedFromInclusive = m.instructions.getLast();
+
+		m.visitVarInsn(Opcodes.ALOAD, 2);
+		m.visitLdcInsn("a");
+		m.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/String", "equals",
+				"(Ljava/lang/Object;)Z", false);
+		// if equal "a", then goto its case
+		m.visitJumpInsn(Opcodes.IFNE, case1);
+
+		m.visitVarInsn(Opcodes.ALOAD, 2);
+		m.visitLdcInsn("\0a");
+		m.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/String", "equals",
+				"(Ljava/lang/Object;)Z", false);
+		// if equal "\0a", then goto its case
+		m.visitJumpInsn(Opcodes.IFNE, case2);
+
+		// goto default case
+		m.visitJumpInsn(Opcodes.GOTO, caseDefault);
+
+		m.visitLabel(h2);
+
+		m.visitVarInsn(Opcodes.ALOAD, 2);
+		m.visitLdcInsn("b");
+		m.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/String", "equals",
+				"(Ljava/lang/Object;)Z", false);
+		// if equal "b", then goto its case
+		m.visitJumpInsn(Opcodes.IFNE, case3);
+
+		// goto default case
+		m.visitJumpInsn(Opcodes.GOTO, caseDefault);
+		final AbstractInsnNode expectedToInclusive = m.instructions.getLast();
+
+		m.visitLabel(caseDefault);
+		m.visitInsn(Opcodes.RETURN);
+		expectedNewTargets.add(m.instructions.getLast());
+		m.visitLabel(case1);
+		m.visitInsn(Opcodes.RETURN);
+		expectedNewTargets.add(m.instructions.getLast());
+		m.visitLabel(case2);
+		m.visitInsn(Opcodes.RETURN);
+		expectedNewTargets.add(m.instructions.getLast());
+		m.visitLabel(case3);
+		m.visitInsn(Opcodes.RETURN);
+		expectedNewTargets.add(m.instructions.getLast());
+
+		filter.filter(m, context, output);
+
+		assertEquals(expectedFromInclusive.getPrevious(), source);
+		assertEquals(expectedNewTargets, newTargets);
+		assertEquals(expectedFromInclusive, fromInclusive);
+		assertEquals(expectedToInclusive, toInclusive);
+	}
+
+}
diff --git a/org.jacoco.core/src/org/jacoco/core/internal/analysis/MethodAnalyzer.java b/org.jacoco.core/src/org/jacoco/core/internal/analysis/MethodAnalyzer.java
index ba862adc..82b97466 100644
--- a/org.jacoco.core/src/org/jacoco/core/internal/analysis/MethodAnalyzer.java
+++ b/org.jacoco.core/src/org/jacoco/core/internal/analysis/MethodAnalyzer.java
@@ -173,6 +173,13 @@ public class MethodAnalyzer extends MethodProbesVisitor
 		}
 	}
 
+	private final Map<AbstractInsnNode, Set<AbstractInsnNode>> replacements = new HashMap<AbstractInsnNode, Set<AbstractInsnNode>>();
+
+	public void replaceBranches(final AbstractInsnNode source,
+			final Set<AbstractInsnNode> newTargets) {
+		replacements.put(source, newTargets);
+	}
+
 	@Override
 	public void visitLabel(final Label label) {
 		currentLabel.add(label);
@@ -362,6 +369,7 @@ public class MethodAnalyzer extends MethodProbesVisitor
 		for (final CoveredProbe p : coveredProbes) {
 			p.instruction.setCovered(p.branch);
 		}
+
 		// Merge:
 		for (final Instruction i : instructions) {
 			final AbstractInsnNode m = i.getNode();
@@ -371,6 +379,7 @@ public class MethodAnalyzer extends MethodProbesVisitor
 				nodeToInstruction.get(r).merge(i);
 			}
 		}
+
 		// Report result:
 		coverage.ensureCapacity(firstLine, lastLine);
 		for (final Instruction i : instructions) {
@@ -378,8 +387,23 @@ public class MethodAnalyzer extends MethodProbesVisitor
 				continue;
 			}
 
-			final int total = i.getBranches();
-			final int covered = i.getCoveredBranches();
+			final int total;
+			final int covered;
+			final Set<AbstractInsnNode> r = replacements.get(i.getNode());
+			if (r != null) {
+				int cb = 0;
+				for (AbstractInsnNode b : r) {
+					if (nodeToInstruction.get(b).getCoveredBranches() > 0) {
+						cb++;
+					}
+				}
+				total = r.size();
+				covered = cb;
+			} else {
+				total = i.getBranches();
+				covered = i.getCoveredBranches();
+			}
+
 			final ICounter instrCounter = covered == 0 ? CounterImpl.COUNTER_1_0
 					: CounterImpl.COUNTER_0_1;
 			final ICounter branchCounter = total > 1
diff --git a/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/Filters.java b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/Filters.java
index b235cfb8..bdb0854b 100644
--- a/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/Filters.java
+++ b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/Filters.java
@@ -31,9 +31,10 @@ public final class Filters implements IFilter {
 			new TryWithResourcesJavac11Filter(),
 			new TryWithResourcesJavacFilter(), new TryWithResourcesEcjFilter(),
 			new FinallyFilter(), new PrivateEmptyNoArgConstructorFilter(),
-			new StringSwitchJavacFilter(), new EnumEmptyConstructorFilter(),
-			new AnnotationGeneratedFilter(), new KotlinGeneratedFilter(),
-			new KotlinLateinitFilter(), new KotlinWhenSealedFilter());
+			new StringSwitchJavacFilter(), new StringSwitchEcjFilter(),
+			new EnumEmptyConstructorFilter(), new AnnotationGeneratedFilter(),
+			new KotlinGeneratedFilter(), new KotlinLateinitFilter(),
+			new KotlinWhenSealedFilter());
 
 	private final IFilter[] filters;
 
diff --git a/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/IFilterOutput.java b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/IFilterOutput.java
index 4ca9b814..bbcbf00e 100644
--- a/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/IFilterOutput.java
+++ b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/IFilterOutput.java
@@ -11,6 +11,8 @@
  *******************************************************************************/
 package org.jacoco.core.internal.analysis.filter;
 
+import java.util.Set;
+
 import org.objectweb.asm.tree.AbstractInsnNode;
 
 /**
@@ -41,4 +43,16 @@ public interface IFilterOutput {
 	 */
 	void merge(AbstractInsnNode i1, AbstractInsnNode i2);
 
+	/**
+	 * Marks instruction whose outgoing branches should be replaced during
+	 * computation of coverage.
+	 *
+	 * @param source
+	 *            instruction which branches should be replaced
+	 * @param newTargets
+	 *            new targets of branches
+	 */
+	void replaceBranches(AbstractInsnNode source,
+			Set<AbstractInsnNode> newTargets);
+
 }
diff --git a/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/StringSwitchEcjFilter.java b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/StringSwitchEcjFilter.java
new file mode 100644
index 00000000..cbd2a216
--- /dev/null
+++ b/org.jacoco.core/src/org/jacoco/core/internal/analysis/filter/StringSwitchEcjFilter.java
@@ -0,0 +1,108 @@
+/*******************************************************************************
+ * Copyright (c) 2009, 2018 Mountainminds GmbH & Co. KG and Contributors
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Evgeny Mandrikov - initial API and implementation
+ *
+ *******************************************************************************/
+package org.jacoco.core.internal.analysis.filter;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.tree.AbstractInsnNode;
+import org.objectweb.asm.tree.JumpInsnNode;
+import org.objectweb.asm.tree.LabelNode;
+import org.objectweb.asm.tree.LookupSwitchInsnNode;
+import org.objectweb.asm.tree.MethodNode;
+import org.objectweb.asm.tree.TableSwitchInsnNode;
+
+/**
+ * Filters code that is generated by ECJ for a <code>switch</code> statement
+ * with a <code>String</code>.
+ */
+public final class StringSwitchEcjFilter implements IFilter {
+
+	public void filter(final MethodNode methodNode,
+			final IFilterContext context, final IFilterOutput output) {
+		final Matcher matcher = new Matcher();
+		for (AbstractInsnNode i = methodNode.instructions
+				.getFirst(); i != null; i = i.getNext()) {
+			matcher.match(i, output);
+		}
+	}
+
+	private static class Matcher extends AbstractMatcher {
+		public void match(final AbstractInsnNode start,
+				final IFilterOutput output) {
+
+			cursor = start;
+
+			nextIsVar(Opcodes.ASTORE, "s");
+			nextIsInvokeVirtual("java/lang/String", "hashCode");
+			nextIsSwitch();
+			if (cursor == null) {
+				return;
+			}
+
+			final AbstractInsnNode s = cursor;
+			final int hashCodes;
+			final LabelNode defaultLabel;
+			if (s.getOpcode() == Opcodes.LOOKUPSWITCH) {
+				final LookupSwitchInsnNode lookupSwitch = (LookupSwitchInsnNode) cursor;
+				defaultLabel = lookupSwitch.dflt;
+				hashCodes = lookupSwitch.labels.size();
+			} else {
+				final TableSwitchInsnNode tableSwitch = (TableSwitchInsnNode) cursor;
+				defaultLabel = tableSwitch.dflt;
+				hashCodes = tableSwitch.labels.size();
+			}
+
+			final Set<AbstractInsnNode> replacements = new HashSet<AbstractInsnNode>();
+			replacements.add(instructionAfterLabel(defaultLabel));
+
+			for (int i = 0; i < hashCodes; i++) {
+				while (true) {
+					nextIsVar(Opcodes.ALOAD, "s");
+					nextIs(Opcodes.LDC);
+					nextIsInvokeVirtual("java/lang/String", "equals");
+					// jump to case
+					nextIs(Opcodes.IFNE);
+					if (cursor == null) {
+						return;
+					}
+
+					replacements.add(instructionAfterLabel(
+							((JumpInsnNode) cursor).label));
+
+					if (cursor.getNext().getOpcode() == Opcodes.GOTO) {
+						// end of comparisons for same hashCode
+						// jump to default
+						nextIs(Opcodes.GOTO);
+						break;
+					}
+				}
+			}
+
+			output.ignore(s.getNext(), cursor);
+			output.replaceBranches(s, replacements);
+		}
+	}
+
+	private static AbstractInsnNode instructionAfterLabel(
+			final LabelNode label) {
+		AbstractInsnNode i = label.getNext();
+		while (i.getType() == AbstractInsnNode.FRAME
+				|| i.getType() == AbstractInsnNode.LABEL
+				|| i.getType() == AbstractInsnNode.LINE) {
+			i = i.getNext();
+		}
+		return i;
+	}
+
+}
diff --git a/org.jacoco.doc/docroot/doc/changes.html b/org.jacoco.doc/docroot/doc/changes.html
index 35c61284..46208992 100644
--- a/org.jacoco.doc/docroot/doc/changes.html
+++ b/org.jacoco.doc/docroot/doc/changes.html
@@ -31,6 +31,10 @@
       (GitHub <a href="https://github.com/jacoco/jacoco/issues/669">#669</a>).</li>
   <li>Synthetic classes are filtered out during generation of report
       (GitHub <a href="https://github.com/jacoco/jacoco/issues/668">#668</a>).</li>
+  <li>Part of bytecode generated by ECJ for <code>switch</code> statements on
+      <code>java.lang.String</code> values is filtered out during generation of
+      report
+      (GitHub <a href="https://github.com/jacoco/jacoco/issues/735">#735</a>).</li>
   <li>Methods added by the Kotlin compiler are filtered out during generation
       of report. Idea and implementation by Nikolay Krasko
       (GitHub <a href="https://github.com/jacoco/jacoco/issues/689">#689</a>).</li>