Merge pull request #185 from jacoco/issue-185

Print warning if class ids differ

29 files changed, 400 insertions, 115 deletions

diff --git a/jacoco-maven-plugin.test/it/it-report-nomatch/nomatch.exec b/jacoco-maven-plugin.test/it/it-report-nomatch/nomatch.exec
new file mode 100644
index 00000000..31cad96f
--- /dev/null
+++ b/jacoco-maven-plugin.test/it/it-report-nomatch/nomatch.exec
diff --git a/jacoco-maven-plugin.test/it/it-report-nomatch/pom.xml b/jacoco-maven-plugin.test/it/it-report-nomatch/pom.xml
new file mode 100644
index 00000000..73b6a096
--- /dev/null
+++ b/jacoco-maven-plugin.test/it/it-report-nomatch/pom.xml
@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+   Copyright (c) 2009, 2014 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
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>jacoco</groupId>
+    <artifactId>setup-parent</artifactId>
+    <version>1.0-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>it-report-nomatch</artifactId>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>@project.groupId@</groupId>
+        <artifactId>jacoco-maven-plugin</artifactId>
+        <executions>
+          <execution>
+            <id>report</id>
+            <phase>prepare-package</phase>
+            <goals>
+              <goal>report</goal>
+            </goals>
+            <configuration>
+              <dataFile>nomatch.exec</dataFile>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+</project>
diff --git a/jacoco-maven-plugin.test/it/it-report-nomatch/src/main/java/Example.java b/jacoco-maven-plugin.test/it/it-report-nomatch/src/main/java/Example.java
new file mode 100644
index 00000000..5d2c1392
--- /dev/null
+++ b/jacoco-maven-plugin.test/it/it-report-nomatch/src/main/java/Example.java
@@ -0,0 +1,14 @@
+/*******************************************************************************
+ * Copyright (c) 2009, 2014 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:
+ *    Marc R. Hoffmann - initial API and implementation
+ *
+ *******************************************************************************/
+public class Example {
+
+}
diff --git a/jacoco-maven-plugin.test/it/it-report-nomatch/verify.bsh b/jacoco-maven-plugin.test/it/it-report-nomatch/verify.bsh
new file mode 100644
index 00000000..e45c9ad7
--- /dev/null
+++ b/jacoco-maven-plugin.test/it/it-report-nomatch/verify.bsh
@@ -0,0 +1,24 @@
+/*******************************************************************************
+ * Copyright (c) 2009, 2014 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
+ *
+ *******************************************************************************/
+import java.io.*;
+import org.codehaus.plexus.util.*;
+
+String buildLog = FileUtils.fileRead( new File( basedir, "build.log" ) );
+if ( buildLog.indexOf( "Classes in bundle 'it-report-nomatch' do no match with execution data." ) < 0 ) {
+    throw new RuntimeException( "Warning 1 was not printed" );
+}
+if ( buildLog.indexOf( "For report generation the same class files must be used as at runtime." ) < 0 ) {
+    throw new RuntimeException( "Warning 2 was not printed" );
+}
+if ( buildLog.indexOf( "Execution data for class Example does not match." ) < 0 ) {
+    throw new RuntimeException( "Warning 3 was not printed" );
+}
diff --git a/jacoco-maven-plugin/src/org/jacoco/maven/AbstractReportMojo.java b/jacoco-maven-plugin/src/org/jacoco/maven/AbstractReportMojo.java
index ac735c17..4c694aa8 100644
--- a/jacoco-maven-plugin/src/org/jacoco/maven/AbstractReportMojo.java
+++ b/jacoco-maven-plugin/src/org/jacoco/maven/AbstractReportMojo.java
@@ -215,7 +215,7 @@ public abstract class AbstractReportMojo extends AbstractMavenReport {
 		final FileFilter fileFilter = new FileFilter(this.getIncludes(),
 				this.getExcludes());
 		final BundleCreator creator = new BundleCreator(this.getProject(),
-				fileFilter);
+				fileFilter, getLog());
 		final IBundleCoverage bundle = creator.createBundle(executionDataStore);
 		final SourceFileCollection locator = new SourceFileCollection(
 				getCompileSourceRoots(), sourceEncoding);
diff --git a/jacoco-maven-plugin/src/org/jacoco/maven/BundleCreator.java b/jacoco-maven-plugin/src/org/jacoco/maven/BundleCreator.java
index 3088399f..e20c4aef 100644
--- a/jacoco-maven-plugin/src/org/jacoco/maven/BundleCreator.java
+++ b/jacoco-maven-plugin/src/org/jacoco/maven/BundleCreator.java
@@ -12,15 +12,20 @@
  *******************************************************************************/
 package org.jacoco.maven;
 
+import static java.lang.String.format;
+
 import java.io.File;
 import java.io.IOException;
+import java.util.Collection;
 import java.util.List;
 
+import org.apache.maven.plugin.logging.Log;
 import org.apache.maven.project.MavenProject;
 import org.codehaus.plexus.util.FileUtils;
 import org.jacoco.core.analysis.Analyzer;
 import org.jacoco.core.analysis.CoverageBuilder;
 import org.jacoco.core.analysis.IBundleCoverage;
+import org.jacoco.core.analysis.IClassCoverage;
 import org.jacoco.core.data.ExecutionDataStore;
 
 /**
@@ -30,6 +35,7 @@ public final class BundleCreator {
 
 	private final MavenProject project;
 	private final FileFilter fileFilter;
+	private final Log log;
 
 	/**
 	 * Construct a new BundleCreator given the MavenProject and FileFilter.
@@ -38,10 +44,14 @@ public final class BundleCreator {
 	 *            the MavenProject
 	 * @param fileFilter
 	 *            the FileFilter
+	 * @param log
+	 *            for log output
 	 */
-	public BundleCreator(final MavenProject project, final FileFilter fileFilter) {
+	public BundleCreator(final MavenProject project,
+			final FileFilter fileFilter, final Log log) {
 		this.project = project;
 		this.fileFilter = fileFilter;
+		this.log = log;
 	}
 
 	/**
@@ -68,6 +78,28 @@ public final class BundleCreator {
 			analyzer.analyzeAll(file);
 		}
 
-		return builder.getBundle(this.project.getName());
+		final IBundleCoverage bundle = builder
+				.getBundle(this.project.getName());
+		logBundleInfo(bundle, builder.getNoMatchClasses());
+
+		return bundle;
+	}
+
+	private void logBundleInfo(final IBundleCoverage bundle,
+			final Collection<IClassCoverage> nomatch) {
+		log.info(format("Analyzed bundle '%s' with %s classes",
+				bundle.getName(),
+				Integer.valueOf(bundle.getClassCounter().getTotalCount())));
+		if (!nomatch.isEmpty()) {
+			log.warn(format(
+					"Classes in bundle '%s' do no match with execution data. "
+							+ "For report generation the same class files must be used as at runtime.",
+					bundle.getName()));
+			for (final IClassCoverage c : nomatch) {
+				log.warn(format("Execution data for class %s does not match.",
+						c.getName()));
+			}
+		}
 	}
+
 }
diff --git a/jacoco-maven-plugin/src/org/jacoco/maven/CheckMojo.java b/jacoco-maven-plugin/src/org/jacoco/maven/CheckMojo.java
index 94779c6a..f5f9a55a 100644
--- a/jacoco-maven-plugin/src/org/jacoco/maven/CheckMojo.java
+++ b/jacoco-maven-plugin/src/org/jacoco/maven/CheckMojo.java
@@ -54,10 +54,10 @@ public class CheckMojo extends AbstractJacocoMojo implements IViolationsOutput {
 	 * If a limit refers to a ratio the range is from 0.0 to 1.0 where the
 	 * number of decimal places will also determine the precision in error
 	 * messages.
-	 *
+	 * 
 	 * Note that you <b>must</b> use <tt>implementation</tt> hints for
-	 * <tt>rule</tt> and <tt>limit</tt> when using Maven 2, with Maven 3 you
-	 * do not need to specify the attributes.
+	 * <tt>rule</tt> and <tt>limit</tt> when using Maven 2, with Maven 3 you do
+	 * not need to specify the attributes.
 	 * </p>
 	 * 
 	 * <p>
@@ -137,11 +137,12 @@ public class CheckMojo extends AbstractJacocoMojo implements IViolationsOutput {
 			getLog().info(MSG_SKIPPING + dataFile);
 			return false;
 		}
-		final File classesDirectory = new File(getProject().getBuild().getOutputDirectory());
+		final File classesDirectory = new File(getProject().getBuild()
+				.getOutputDirectory());
 		if (!classesDirectory.exists()) {
 			getLog().info(
-					"Skipping JaCoCo execution due to missing classes directory:" +
-					classesDirectory);
+					"Skipping JaCoCo execution due to missing classes directory:"
+							+ classesDirectory);
 			return false;
 		}
 		return true;
@@ -189,7 +190,7 @@ public class CheckMojo extends AbstractJacocoMojo implements IViolationsOutput {
 		final FileFilter fileFilter = new FileFilter(this.getIncludes(),
 				this.getExcludes());
 		final BundleCreator creator = new BundleCreator(getProject(),
-				fileFilter);
+				fileFilter, getLog());
 		try {
 			final ExecutionDataStore executionData = loadExecutionData();
 			return creator.createBundle(executionData);
diff --git a/org.jacoco.ant.test/src/org/jacoco/ant/ReportTaskTest.xml b/org.jacoco.ant.test/src/org/jacoco/ant/ReportTaskTest.xml
index bed8b2f0..04ab9802 100644
--- a/org.jacoco.ant.test/src/org/jacoco/ant/ReportTaskTest.xml
+++ b/org.jacoco.ant.test/src/org/jacoco/ant/ReportTaskTest.xml
@@ -117,6 +117,24 @@
 		</jacoco:report>
 		<au:assertLogDoesntContain level="warn" text="source code annotation"/>
 	</target>
+
+	<target name="testReportWithNoMatch">
+		<property name="nomatch.file" location="${basedir}/data/nomatch.exec"/>
+		<jacoco:report>
+			<executiondata>
+				<file file="${nomatch.file}"/>
+			</executiondata>
+			<structure name="root">
+				<classfiles>
+					<path location="${org.jacoco.ant.reportTaskTest.classes.dir}"/>
+				</classfiles>
+			</structure>
+		</jacoco:report>
+		<au:assertLogContains level="warn" text="Classes in bundle 'root' do no match with execution data."/>
+		<au:assertLogContains level="warn" text="For report generation the same class files must be used as at runtime."/>
+		<au:assertLogContains level="warn" text="Execution data for class org/jacoco/ant/TestTarget does not match."/>
+	</target>
+
 	
 	<!-- HTML Output -->
 	
@@ -220,7 +238,7 @@
 				<sourcefiles encoding="UTF-8">
 					<fileset dir="${org.jacoco.ant.reportTaskTest.sources.dir}" />
 				</sourcefiles>
-            </structure>
+			</structure>
 			<html destdir="${temp.dir}"/>
 		</jacoco:report>
 		
@@ -239,7 +257,7 @@
 				<sourcefiles encoding="UTF-8" tabwidth="13">
 					<fileset dir="${org.jacoco.ant.reportTaskTest.sources.dir}" />
 				</sourcefiles>
-            </structure>
+			</structure>
 			<html destdir="${temp.dir}"/>
 		</jacoco:report>
 		
@@ -287,7 +305,7 @@
 				<sourcefiles encoding="UTF-8">
 					<fileset dir="${org.jacoco.ant.reportTaskTest.sources.dir}" />
 				</sourcefiles>
-            </structure>
+			</structure>
 			<html destdir="${temp.dir}"/>
 		</jacoco:report>
 		
@@ -304,7 +322,7 @@
 				<sourcefiles encoding="UTF-8">
 					<dirset dir="${org.jacoco.ant.reportTaskTest.sources.dir}/.." includes="src" />
 				</sourcefiles>
-            </structure>
+			</structure>
 			<html destdir="${temp.dir}"/>
 		</jacoco:report>
 		
@@ -323,7 +341,7 @@
 				<sourcefiles encoding="UTF-16">
 					<fileset dir="${temp.dir}" />
 				</sourcefiles>
-            </structure>
+			</structure>
 			<html destdir="${temp.dir}"/>
 		</jacoco:report>
 		
@@ -342,7 +360,7 @@
 				<sourcefiles encoding="UTF-8">
 					<fileset dir="${org.jacoco.ant.reportTaskTest.sources.dir}" />
 				</sourcefiles>
-            </structure>
+			</structure>
 			<html destdir="${temp.dir}" locale="gr"/>
 		</jacoco:report>
 		
@@ -423,7 +441,7 @@
 				<sourcefiles encoding="UTF-8">
 					<fileset dir="${org.jacoco.ant.reportTaskTest.sources.dir}" />
 				</sourcefiles>
-            </structure>
+			</structure>
 			<check>
 				<rule element="CLASS">
 					<limit counter="METHOD" value="MISSEDCOUNT" maximum="100"/>
@@ -442,7 +460,7 @@
 					<sourcefiles encoding="UTF-8">
 						<fileset dir="${org.jacoco.ant.reportTaskTest.sources.dir}" />
 					</sourcefiles>
-            	</structure>
+				</structure>
 				<check>
 					<rule element="BUNDLE">
 						<limit counter="INSTRUCTION" value="COVEREDRATIO" minimum="0.90"/>
@@ -462,7 +480,7 @@
 				<sourcefiles encoding="UTF-8">
 					<fileset dir="${org.jacoco.ant.reportTaskTest.sources.dir}" />
 				</sourcefiles>
-           	</structure>
+			</structure>
 			<check failonviolation="false" violationsproperty="violation">
 				<rule element="BUNDLE">
 					<limit counter="METHOD" value="COVEREDRATIO" minimum="0.50"/>
diff --git a/org.jacoco.ant.test/src/org/jacoco/ant/data/nomatch.exec b/org.jacoco.ant.test/src/org/jacoco/ant/data/nomatch.exec
new file mode 100644
index 00000000..ef7d62ae
--- /dev/null
+++ b/org.jacoco.ant.test/src/org/jacoco/ant/data/nomatch.exec
diff --git a/org.jacoco.ant/src/org/jacoco/ant/ReportTask.java b/org.jacoco.ant/src/org/jacoco/ant/ReportTask.java
index ba58894a..90bad95d 100644
--- a/org.jacoco.ant/src/org/jacoco/ant/ReportTask.java
+++ b/org.jacoco.ant/src/org/jacoco/ant/ReportTask.java
@@ -18,6 +18,7 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Locale;
@@ -32,6 +33,7 @@ import org.apache.tools.ant.util.FileUtils;
 import org.jacoco.core.analysis.Analyzer;
 import org.jacoco.core.analysis.CoverageBuilder;
 import org.jacoco.core.analysis.IBundleCoverage;
+import org.jacoco.core.analysis.IClassCoverage;
 import org.jacoco.core.analysis.ICoverageNode;
 import org.jacoco.core.data.ExecutionDataStore;
 import org.jacoco.core.data.SessionInfoStore;
@@ -543,9 +545,6 @@ public class ReportTask extends Task {
 			}
 		} else {
 			final IBundleCoverage bundle = createBundle(group);
-			log(format("Writing group \"%s\" with %s classes",
-					bundle.getName(),
-					Integer.valueOf(bundle.getClassCounter().getTotalCount())));
 			final SourceFilesElement sourcefiles = group.sourcefiles;
 			final AntResourcesLocator locator = new AntResourcesLocator(
 					sourcefiles.encoding, sourcefiles.tabWidth);
@@ -571,14 +570,32 @@ public class ReportTask extends Task {
 				in.close();
 			}
 		}
-		return builder.getBundle(group.name);
+		final IBundleCoverage bundle = builder.getBundle(group.name);
+		logBundleInfo(bundle, builder.getNoMatchClasses());
+		return bundle;
+	}
+
+	private void logBundleInfo(final IBundleCoverage bundle,
+			final Collection<IClassCoverage> nomatch) {
+		log(format("Writing bundle '%s' with %s classes", bundle.getName(),
+				Integer.valueOf(bundle.getClassCounter().getTotalCount())));
+		if (!nomatch.isEmpty()) {
+			log(format(
+					"Classes in bundle '%s' do no match with execution data. "
+							+ "For report generation the same class files must be used as at runtime.",
+					bundle.getName()), Project.MSG_WARN);
+			for (final IClassCoverage c : nomatch) {
+				log(format("Execution data for class %s does not match.",
+						c.getName()), Project.MSG_WARN);
+			}
+		}
 	}
 
 	private void checkForMissingDebugInformation(final ICoverageNode node) {
 		if (node.getClassCounter().getTotalCount() > 0
 				&& node.getLineCounter().getTotalCount() == 0) {
 			log(format(
-					"To enable source code annotation class files for bundle '%s' have to be compiled with debug information",
+					"To enable source code annotation class files for bundle '%s' have to be compiled with debug information.",
 					node.getName()), Project.MSG_WARN);
 		}
 	}
diff --git a/org.jacoco.core.test/src/org/jacoco/core/analysis/AnalyzerTest.java b/org.jacoco.core.test/src/org/jacoco/core/analysis/AnalyzerTest.java
index 7e5298aa..f287526b 100644
--- a/org.jacoco.core.test/src/org/jacoco/core/analysis/AnalyzerTest.java
+++ b/org.jacoco.core.test/src/org/jacoco/core/analysis/AnalyzerTest.java
@@ -12,6 +12,8 @@
 package org.jacoco.core.analysis;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
@@ -23,8 +25,9 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Set;
+import java.util.Map;
 import java.util.jar.JarInputStream;
 import java.util.jar.Pack200;
 import java.util.zip.GZIPOutputStream;
@@ -32,6 +35,7 @@ import java.util.zip.ZipEntry;
 import java.util.zip.ZipOutputStream;
 
 import org.jacoco.core.data.ExecutionDataStore;
+import org.jacoco.core.internal.data.CRC64;
 import org.jacoco.core.test.TargetLoader;
 import org.junit.Before;
 import org.junit.Rule;
@@ -48,38 +52,61 @@ public class AnalyzerTest {
 
 	private Analyzer analyzer;
 
-	private final Set<String> classes = new HashSet<String>();
+	private Map<String, IClassCoverage> classes;
+
+	private ExecutionDataStore executionData;
 
 	private class EmptyStructureVisitor implements ICoverageVisitor {
 
 		public void visitCoverage(IClassCoverage coverage) {
 			final String name = coverage.getName();
-			assertTrue("Class already processed: " + name, classes.add(name));
+			assertNull("Class already processed: " + name,
+					classes.put(name, coverage));
 		}
 	}
 
 	@Before
 	public void setup() {
-		analyzer = new Analyzer(new ExecutionDataStore(),
-				new EmptyStructureVisitor());
+		classes = new HashMap<String, IClassCoverage>();
+		executionData = new ExecutionDataStore();
+		analyzer = new Analyzer(executionData, new EmptyStructureVisitor());
 	}
 
 	@Test
-	public void testAnalyzeClass1() throws IOException {
+	public void testAnalyzeClassFromStream() throws IOException {
 		analyzer.analyzeClass(TargetLoader.getClassData(AnalyzerTest.class),
 				"Test");
-		assertEquals(
-				Collections.singleton("org/jacoco/core/analysis/AnalyzerTest"),
-				classes);
+		assertClasses("org/jacoco/core/analysis/AnalyzerTest");
+	}
+
+	@Test
+	public void testAnalyzeClassFromByteArray() throws IOException {
+		analyzer.analyzeClass(
+				TargetLoader.getClassDataAsBytes(AnalyzerTest.class), "Test");
+		assertClasses("org/jacoco/core/analysis/AnalyzerTest");
+		assertFalse(classes.get("org/jacoco/core/analysis/AnalyzerTest")
+				.isNoMatch());
 	}
 
 	@Test
-	public void testAnalyzeClass2() throws IOException {
+	public void testAnalyzeClassIdMatch() throws IOException {
+		final byte[] bytes = TargetLoader
+				.getClassDataAsBytes(AnalyzerTest.class);
+		executionData.get(Long.valueOf(CRC64.checksum(bytes)),
+				"org/jacoco/core/analysis/AnalyzerTest", 100);
+		analyzer.analyzeClass(bytes, "Test");
+		assertFalse(classes.get("org/jacoco/core/analysis/AnalyzerTest")
+				.isNoMatch());
+	}
+
+	@Test
+	public void testAnalyzeClassNoIdMatch() throws IOException {
+		executionData.get(Long.valueOf(0),
+				"org/jacoco/core/analysis/AnalyzerTest", 100);
 		analyzer.analyzeClass(
 				TargetLoader.getClassDataAsBytes(AnalyzerTest.class), "Test");
-		assertEquals(
-				Collections.singleton("org/jacoco/core/analysis/AnalyzerTest"),
-				classes);
+		assertTrue(classes.get("org/jacoco/core/analysis/AnalyzerTest")
+				.isNoMatch());
 	}
 
 	@Test
@@ -100,9 +127,7 @@ public class AnalyzerTest {
 		final int count = analyzer.analyzeAll(
 				TargetLoader.getClassData(AnalyzerTest.class), "Test");
 		assertEquals(1, count);
-		assertEquals(
-				Collections.singleton("org/jacoco/core/analysis/AnalyzerTest"),
-				classes);
+		assertClasses("org/jacoco/core/analysis/AnalyzerTest");
 	}
 
 	@Test
@@ -116,9 +141,7 @@ public class AnalyzerTest {
 		final int count = analyzer.analyzeAll(
 				new ByteArrayInputStream(buffer.toByteArray()), "Test");
 		assertEquals(1, count);
-		assertEquals(
-				Collections.singleton("org/jacoco/core/analysis/AnalyzerTest"),
-				classes);
+		assertClasses("org/jacoco/core/analysis/AnalyzerTest");
 	}
 
 	@Test
@@ -151,9 +174,7 @@ public class AnalyzerTest {
 		final int count = analyzer.analyzeAll(new ByteArrayInputStream(
 				pack200buffer.toByteArray()), "Test");
 		assertEquals(1, count);
-		assertEquals(
-				Collections.singleton("org/jacoco/core/analysis/AnalyzerTest"),
-				classes);
+		assertClasses("org/jacoco/core/analysis/AnalyzerTest");
 	}
 
 	@Test
@@ -161,7 +182,7 @@ public class AnalyzerTest {
 		final int count = analyzer.analyzeAll(new ByteArrayInputStream(
 				new byte[0]), "Test");
 		assertEquals(0, count);
-		assertEquals(Collections.emptySet(), classes);
+		assertEquals(Collections.emptyMap(), classes);
 	}
 
 	@Test
@@ -169,9 +190,7 @@ public class AnalyzerTest {
 		createClassfile("bin1", AnalyzerTest.class);
 		final int count = analyzer.analyzeAll(folder.getRoot());
 		assertEquals(1, count);
-		assertEquals(
-				Collections.singleton("org/jacoco/core/analysis/AnalyzerTest"),
-				classes);
+		assertClasses("org/jacoco/core/analysis/AnalyzerTest");
 	}
 
 	@Test
@@ -181,10 +200,8 @@ public class AnalyzerTest {
 		String path = "bin1" + File.pathSeparator + "bin2";
 		final int count = analyzer.analyzeAll(path, folder.getRoot());
 		assertEquals(2, count);
-		assertEquals(
-				new HashSet<String>(Arrays.asList(
-						"org/jacoco/core/analysis/Analyzer",
-						"org/jacoco/core/analysis/AnalyzerTest")), classes);
+		assertClasses("org/jacoco/core/analysis/Analyzer",
+				"org/jacoco/core/analysis/AnalyzerTest");
 	}
 
 	@Test(expected = IOException.class)
@@ -231,4 +248,9 @@ public class AnalyzerTest {
 		out.close();
 	}
 
+	private void assertClasses(String... classNames) {
+		assertEquals(new HashSet<String>(Arrays.asList(classNames)),
+				classes.keySet());
+	}
+
 }
diff --git a/org.jacoco.core.test/src/org/jacoco/core/analysis/CoverageBuilderTest.java b/org.jacoco.core.test/src/org/jacoco/core/analysis/CoverageBuilderTest.java
index c2d5a4d3..4a54c702 100644
--- a/org.jacoco.core.test/src/org/jacoco/core/analysis/CoverageBuilderTest.java
+++ b/org.jacoco.core.test/src/org/jacoco/core/analysis/CoverageBuilderTest.java
@@ -49,7 +49,7 @@ public class CoverageBuilderTest {
 		method.increment(CounterImpl.COUNTER_1_0, CounterImpl.COUNTER_0_0, 7);
 		method.increment(CounterImpl.COUNTER_1_0, CounterImpl.COUNTER_0_0, 8);
 		method.incrementMethodCounter();
-		addClass(123L, "Sample", null, method);
+		addClass(123L, false, "Sample", null, method);
 
 		final Collection<IClassCoverage> classes = coverageBuilder.getClasses();
 		assertEquals(1, classes.size());
@@ -81,7 +81,7 @@ public class CoverageBuilderTest {
 		method.increment(CounterImpl.COUNTER_0_1, CounterImpl.COUNTER_0_0, 7);
 		method.increment(CounterImpl.COUNTER_0_1, CounterImpl.COUNTER_0_0, 8);
 		method.incrementMethodCounter();
-		addClass(123L, "Sample", null, method);
+		addClass(123L, false, "Sample", null, method);
 
 		final Collection<IClassCoverage> classes = coverageBuilder.getClasses();
 		assertEquals(1, classes.size());
@@ -109,7 +109,7 @@ public class CoverageBuilderTest {
 	public void testIgnoreClassesWithoutCode() {
 		final MethodCoverageImpl method = new MethodCoverageImpl("doit", "()V",
 				null);
-		addClass(123L, "Sample", null, method);
+		addClass(123L, false, "Sample", null, method);
 
 		final Collection<IClassCoverage> classes = coverageBuilder.getClasses();
 		assertTrue(classes.isEmpty());
@@ -119,24 +119,24 @@ public class CoverageBuilderTest {
 	public void testDuplicateClassNameDifferent() {
 		MethodCoverageImpl method = new MethodCoverageImpl("doit", "()V", null);
 		method.increment(CounterImpl.COUNTER_1_0, CounterImpl.COUNTER_0_0, 3);
-		addClass(123L, "Sample", null, method);
+		addClass(123L, false, "Sample", null, method);
 
 		// Add class with different id must fail:
 		method = new MethodCoverageImpl("doit", "()V", null);
 		method.increment(CounterImpl.COUNTER_1_0, CounterImpl.COUNTER_0_0, 3);
-		addClass(345L, "Sample", null, method);
+		addClass(345L, false, "Sample", null, method);
 	}
 
 	@Test
 	public void testDuplicateClassNameIdentical() {
 		MethodCoverageImpl method = new MethodCoverageImpl("doit", "()V", null);
 		method.increment(CounterImpl.COUNTER_1_0, CounterImpl.COUNTER_0_0, 3);
-		addClass(123L, "Sample", null, method);
+		addClass(123L, false, "Sample", null, method);
 
 		// Add class with same id:
 		method = new MethodCoverageImpl("doit", "()V", null);
 		method.increment(CounterImpl.COUNTER_1_0, CounterImpl.COUNTER_0_0, 3);
-		addClass(123L, "Sample", null, method);
+		addClass(123L, false, "Sample", null, method);
 
 		// Second add must be ignored:
 		final Collection<IClassCoverage> classes = coverageBuilder.getClasses();
@@ -148,12 +148,12 @@ public class CoverageBuilderTest {
 		final MethodCoverageImpl method1 = new MethodCoverageImpl("doit",
 				"()V", null);
 		method1.increment(CounterImpl.COUNTER_1_0, CounterImpl.COUNTER_0_0, 3);
-		addClass(123L, "Sample", "Sample.java", method1);
+		addClass(123L, false, "Sample", "Sample.java", method1);
 
 		final MethodCoverageImpl method2 = new MethodCoverageImpl("doit",
 				"()V", null);
 		method2.increment(CounterImpl.COUNTER_1_0, CounterImpl.COUNTER_0_0, 6);
-		addClass(234L, "Second", "Sample.java", method2);
+		addClass(234L, false, "Second", "Sample.java", method2);
 
 		final Collection<ISourceFileCoverage> sourcefiles = coverageBuilder
 				.getSourceFiles();
@@ -169,17 +169,17 @@ public class CoverageBuilderTest {
 		final MethodCoverageImpl method1 = new MethodCoverageImpl("doit",
 				"()V", null);
 		method1.increment(CounterImpl.COUNTER_1_0, CounterImpl.COUNTER_0_0, 3);
-		addClass(1, "org/jacoco/examples/Sample1", null, method1);
+		addClass(1, false, "org/jacoco/examples/Sample1", null, method1);
 
 		final MethodCoverageImpl method2 = new MethodCoverageImpl("doit",
 				"()V", null);
 		method2.increment(CounterImpl.COUNTER_1_0, CounterImpl.COUNTER_0_0, 6);
-		addClass(2, "org/jacoco/examples/Sample2", null, method2);
+		addClass(2, false, "org/jacoco/examples/Sample2", null, method2);
 
 		final MethodCoverageImpl method3 = new MethodCoverageImpl("doit",
 				"()V", null);
 		method3.increment(CounterImpl.COUNTER_1_0, CounterImpl.COUNTER_0_0, 1);
-		addClass(3, "Sample3", null, method3);
+		addClass(3, false, "Sample3", null, method3);
 
 		IBundleCoverage bundle = coverageBuilder.getBundle("testbundle");
 		assertEquals("testbundle", bundle.getName());
@@ -205,6 +205,27 @@ public class CoverageBuilderTest {
 				getNames(p2.getClasses()));
 	}
 
+	@Test
+	public void testGetNoMatchClasses() {
+		MethodCoverageImpl m = new MethodCoverageImpl("doit", "()V", null);
+		m.increment(CounterImpl.COUNTER_1_0, CounterImpl.COUNTER_0_0, 1);
+		addClass(1, true, "Sample1", null, m);
+
+		m = new MethodCoverageImpl("doit", "()V", null);
+		m.increment(CounterImpl.COUNTER_1_0, CounterImpl.COUNTER_0_0, 2);
+		addClass(2, true, "Sample2", null, m);
+
+		m = new MethodCoverageImpl("doit", "()V", null);
+		m.increment(CounterImpl.COUNTER_1_0, CounterImpl.COUNTER_0_0, 3);
+		addClass(3, false, "Sample3", null, m);
+
+		final Set<String> actual = getNames(coverageBuilder.getNoMatchClasses());
+		final Set<String> expected = new HashSet<String>(Arrays.asList(
+				"Sample1", "Sample2"));
+
+		assertEquals(expected, actual);
+	}
+
 	private Set<String> getNames(Collection<? extends ICoverageNode> nodes) {
 		Set<String> result = new HashSet<String>();
 		for (ICoverageNode n : nodes) {
@@ -213,10 +234,10 @@ public class CoverageBuilderTest {
 		return result;
 	}
 
-	private void addClass(long id, String name, String source,
+	private void addClass(long id, boolean nomatch, String name, String source,
 			MethodCoverageImpl... methods) {
 		final ClassCoverageImpl coverage = new ClassCoverageImpl(name, id,
-				null, "java/lang/Object", new String[0]);
+				nomatch, null, "java/lang/Object", new String[0]);
 		coverage.setSourceFileName(source);
 		for (MethodCoverageImpl m : methods) {
 			coverage.addMethod(m);
diff --git a/org.jacoco.core.test/src/org/jacoco/core/data/ExecutionDataStoreTest.java b/org.jacoco.core.test/src/org/jacoco/core/data/ExecutionDataStoreTest.java
index 83bc8de5..dcf494b9 100644
--- a/org.jacoco.core.test/src/org/jacoco/core/data/ExecutionDataStoreTest.java
+++ b/org.jacoco.core.test/src/org/jacoco/core/data/ExecutionDataStoreTest.java
@@ -46,6 +46,7 @@ public class ExecutionDataStoreTest implements IExecutionDataVisitor {
 	@Test
 	public void testEmpty() {
 		assertNull(store.get(123));
+		assertFalse(store.contains("org/jacoco/example/Foo"));
 		store.accept(this);
 		assertEquals(Collections.emptyMap(), dataOutput);
 	}
@@ -56,6 +57,7 @@ public class ExecutionDataStoreTest implements IExecutionDataVisitor {
 		store.put(new ExecutionData(1000, "Sample", probes));
 		final ExecutionData data = store.get(1000);
 		assertSame(probes, data.getProbes());
+		assertTrue(store.contains("Sample"));
 		store.accept(this);
 		assertEquals(Collections.singletonMap(Long.valueOf(1000), data),
 				dataOutput);
@@ -96,6 +98,7 @@ public class ExecutionDataStoreTest implements IExecutionDataVisitor {
 		assertFalse(data.getProbes()[1]);
 		assertFalse(data.getProbes()[2]);
 		assertSame(data, store.get(id, "Sample", 3));
+		assertTrue(store.contains("Sample"));
 	}
 
 	@Test(expected = IllegalStateException.class)
diff --git a/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/BundleCoverageImplTest.java b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/BundleCoverageImplTest.java
index 00703d9f..63111f11 100644
--- a/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/BundleCoverageImplTest.java
+++ b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/BundleCoverageImplTest.java
@@ -80,10 +80,10 @@ public class BundleCoverageImplTest {
 
 	@Test
 	public void testGroupByPackage() {
-		ClassCoverageImpl ca = new ClassCoverageImpl("p1/A", 1, null,
+		ClassCoverageImpl ca = new ClassCoverageImpl("p1/A", 1, false, null,
 				"java/lang/Object", new String[0]);
 		ca.setSourceFileName("A.java");
-		ClassCoverageImpl cb = new ClassCoverageImpl("p2/B", 2, null,
+		ClassCoverageImpl cb = new ClassCoverageImpl("p2/B", 2, false, null,
 				"java/lang/Object", new String[0]);
 		cb.setSourceFileName("B.java");
 		ISourceFileCoverage sb = new SourceFileCoverageImpl("B.java", "p2");
diff --git a/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/ClassAnalyzerTest.java b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/ClassAnalyzerTest.java
index 7f4f9b25..a1484ef9 100644
--- a/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/ClassAnalyzerTest.java
+++ b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/ClassAnalyzerTest.java
@@ -25,7 +25,7 @@ public class ClassAnalyzerTest {
 
 	@Before
 	public void setup() {
-		analyzer = new ClassAnalyzer(0x0000, null, new StringPool());
+		analyzer = new ClassAnalyzer(0x0000, false, null, new StringPool());
 		analyzer.visit(Opcodes.V1_5, Opcodes.ACC_PUBLIC, "Foo", null,
 				"java/lang/Object", null);
 	}
diff --git a/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/ClassCoverageImplTest.java b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/ClassCoverageImplTest.java
index 1f9cc9bd..39fe29ad 100644
--- a/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/ClassCoverageImplTest.java
+++ b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/ClassCoverageImplTest.java
@@ -12,6 +12,10 @@
 package org.jacoco.core.internal.analysis;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.util.Collections;
 
 import org.jacoco.core.analysis.ICoverageNode;
 import org.jacoco.core.analysis.ISourceNode;
@@ -24,36 +28,45 @@ public class ClassCoverageImplTest {
 
 	@Test
 	public void testProperties() {
-		ClassCoverageImpl data = new ClassCoverageImpl("Sample", 12345,
+		ClassCoverageImpl data = new ClassCoverageImpl("Sample", 12345, false,
 				"LSample;", "java/lang/Object", new String[0]);
 		data.setSourceFileName("Sample.java");
 		assertEquals(ICoverageNode.ElementType.CLASS, data.getElementType());
 		assertEquals("Sample", data.getName());
 		assertEquals(12345, data.getId());
+		assertFalse(data.isNoMatch());
 		assertEquals("LSample;", data.getSignature());
 		assertEquals("java/lang/Object", data.getSuperName());
 		assertEquals(0, data.getInterfaceNames().length);
 		assertEquals("Sample.java", data.getSourceFileName());
+		assertEquals(Collections.emptyList(), data.getMethods());
+	}
+
+	@Test
+	public void testNoMatch() {
+		ClassCoverageImpl data = new ClassCoverageImpl("Sample", 12345, true,
+				"LSample;", "java/lang/Object", new String[0]);
+		assertTrue(data.isNoMatch());
 	}
 
 	@Test
 	public void testGetPackageName1() {
 		ClassCoverageImpl data = new ClassCoverageImpl("ClassInDefaultPackage",
-				0, null, "java/lang/Object", new String[0]);
+				0, false, null, "java/lang/Object", new String[0]);
 		assertEquals("", data.getPackageName());
 	}
 
 	@Test
 	public void testGetPackageName2() {
 		ClassCoverageImpl data = new ClassCoverageImpl(
-				"org/jacoco/examples/Sample", 0, null, "java/lang/Object",
-				new String[0]);
+				"org/jacoco/examples/Sample", 0, false, null,
+				"java/lang/Object", new String[0]);
 		assertEquals("org/jacoco/examples", data.getPackageName());
 	}
 
 	@Test
 	public void testEmptyClass() {
-		ICoverageNode data = new ClassCoverageImpl("Sample", 0, null,
+		ICoverageNode data = new ClassCoverageImpl("Sample", 0, false, null,
 				"java/lang/Object", new String[0]);
 		assertEquals(CounterImpl.COUNTER_0_0, data.getInstructionCounter());
 		assertEquals(CounterImpl.COUNTER_0_0, data.getBranchCounter());
@@ -63,8 +76,8 @@ public class ClassCoverageImplTest {
 
 	@Test
 	public void testAddMethodMissed() {
-		ClassCoverageImpl data = new ClassCoverageImpl("Sample", 0, null,
-				"java/lang/Object", new String[0]);
+		ClassCoverageImpl data = new ClassCoverageImpl("Sample", 0, false,
+				null, "java/lang/Object", new String[0]);
 		data.addMethod(createMethod(false));
 		assertEquals(CounterImpl.COUNTER_1_0, data.getInstructionCounter());
 		assertEquals(CounterImpl.COUNTER_1_0, data.getMethodCounter());
@@ -73,8 +86,8 @@ public class ClassCoverageImplTest {
 
 	@Test
 	public void testAddMethodCovered() {
-		ClassCoverageImpl data = new ClassCoverageImpl("Sample", 0, null,
-				"java/lang/Object", new String[0]);
+		ClassCoverageImpl data = new ClassCoverageImpl("Sample", 0, false,
+				null, "java/lang/Object", new String[0]);
 		data.addMethod(createMethod(true));
 		assertEquals(CounterImpl.COUNTER_0_1, data.getInstructionCounter());
 		assertEquals(CounterImpl.COUNTER_0_1, data.getMethodCounter());
diff --git a/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/PackageCoverageTest.java b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/PackageCoverageTest.java
index e578a80b..2df29176 100644
--- a/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/PackageCoverageTest.java
+++ b/org.jacoco.core.test/src/org/jacoco/core/internal/analysis/PackageCoverageTest.java
@@ -30,8 +30,8 @@ public class PackageCoverageTest {
 	public void testProperties() {
 		Collection<IClassCoverage> classes = Collections
 				.singleton((IClassCoverage) new ClassCoverageImpl(
-						"org/jacoco/test/Sample", 0, null, "java/lang/Object",
-						new String[0]));
+						"org/jacoco/test/Sample", 0, false, null,
+						"java/lang/Object", new String[0]));
 		Collection<ISourceFileCoverage> sourceFiles = Collections
 				.singleton((ISourceFileCoverage) new SourceFileCoverageImpl(
 						"Sample.java", "org/jacoco/test/Sample"));
@@ -47,7 +47,7 @@ public class PackageCoverageTest {
 	public void testCountersWithSources() {
 		// Classes with source reference will not considered for counters:
 		final ClassCoverageImpl classnode = new ClassCoverageImpl(
-				"org/jacoco/test/Sample", 0, null, "java/lang/Object",
+				"org/jacoco/test/Sample", 0, false, null, "java/lang/Object",
 				new String[0]) {
 			{
 				classCounter = CounterImpl.getInstance(9, 0);
@@ -81,7 +81,7 @@ public class PackageCoverageTest {
 	public void testCountersWithoutSources() {
 		// Classes without source reference will be considered for counters:
 		final ClassCoverageImpl classnode = new ClassCoverageImpl(
-				"org/jacoco/test/Sample", 0, null, "java/lang/Object",
+				"org/jacoco/test/Sample", 0, false, null, "java/lang/Object",
 				new String[0]) {
 			{
 				classCounter = CounterImpl.getInstance(1, 0);
diff --git a/org.jacoco.core/src/org/jacoco/core/analysis/Analyzer.java b/org.jacoco.core/src/org/jacoco/core/analysis/Analyzer.java
index f81026d0..de6397dc 100644
--- a/org.jacoco.core/src/org/jacoco/core/analysis/Analyzer.java
+++ b/org.jacoco.core/src/org/jacoco/core/analysis/Analyzer.java
@@ -68,13 +68,24 @@ public class Analyzer {
 	 * 
 	 * @param classid
 	 *            id of the class calculated with {@link CRC64}
+	 * @param className
+	 *            VM name of the class
 	 * @return ASM visitor to write class definition to
 	 */
-	private ClassVisitor createAnalyzingVisitor(final long classid) {
+	private ClassVisitor createAnalyzingVisitor(final long classid,
+			final String className) {
 		final ExecutionData data = executionData.get(classid);
-		final boolean[] probes = data == null ? null : data.getProbes();
-		final ClassAnalyzer analyzer = new ClassAnalyzer(classid, probes,
-				stringPool) {
+		final boolean[] probes;
+		final boolean noMatch;
+		if (data == null) {
+			probes = null;
+			noMatch = executionData.contains(className);
+		} else {
+			probes = data.getProbes();
+			noMatch = false;
+		}
+		final ClassAnalyzer analyzer = new ClassAnalyzer(classid, noMatch,
+				probes, stringPool) {
 			@Override
 			public void visitEnd() {
 				super.visitEnd();
@@ -91,8 +102,8 @@ public class Analyzer {
 	 *            reader with class definitions
 	 */
 	public void analyzeClass(final ClassReader reader) {
-		final ClassVisitor visitor = createAnalyzingVisitor(CRC64
-				.checksum(reader.b));
+		final ClassVisitor visitor = createAnalyzingVisitor(
+				CRC64.checksum(reader.b), reader.getClassName());
 		reader.accept(visitor, 0);
 	}
 
diff --git a/org.jacoco.core/src/org/jacoco/core/analysis/CoverageBuilder.java b/org.jacoco.core/src/org/jacoco/core/analysis/CoverageBuilder.java
index 93db3805..5dad8ea1 100644
--- a/org.jacoco.core/src/org/jacoco/core/analysis/CoverageBuilder.java
+++ b/org.jacoco.core/src/org/jacoco/core/analysis/CoverageBuilder.java
@@ -11,6 +11,7 @@
  *******************************************************************************/
 package org.jacoco.core.analysis;
 
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -78,6 +79,22 @@ public class CoverageBuilder implements ICoverageVisitor {
 				sourcefiles.values());
 	}
 
+	/**
+	 * Returns all classes for which execution data does not match.
+	 * 
+	 * @see IClassCoverage#isNoMatch()
+	 * @return collection of classes with non-matching execution data
+	 */
+	public Collection<IClassCoverage> getNoMatchClasses() {
+		final Collection<IClassCoverage> result = new ArrayList<IClassCoverage>();
+		for (final IClassCoverage c : classes.values()) {
+			if (c.isNoMatch()) {
+				result.add(c);
+			}
+		}
+		return result;
+	}
+
 	// === IStructureVisitor ===
 
 	public void visitCoverage(final IClassCoverage coverage) {
diff --git a/org.jacoco.core/src/org/jacoco/core/analysis/IClassCoverage.java b/org.jacoco.core/src/org/jacoco/core/analysis/IClassCoverage.java
index 4054f632..f05f0daa 100644
--- a/org.jacoco.core/src/org/jacoco/core/analysis/IClassCoverage.java
+++ b/org.jacoco.core/src/org/jacoco/core/analysis/IClassCoverage.java
@@ -30,6 +30,16 @@ public interface IClassCoverage extends ISourceNode {
 	public long getId();
 
 	/**
+	 * Returns if the the analyzed class does match the execution data provided.
+	 * More precisely if execution data is available for a class with the same
+	 * qualified name but with a different class id.
+	 * 
+	 * @return <code>true</code> if this class does not match to the provided
+	 *         execution data.
+	 */
+	public boolean isNoMatch();
+
+	/**
 	 * Returns the VM signature of the class.
 	 * 
 	 * @return VM signature of the class (may be <code>null</code>)
diff --git a/org.jacoco.core/src/org/jacoco/core/data/ExecutionDataStore.java b/org.jacoco.core/src/org/jacoco/core/data/ExecutionDataStore.java
index d73ce6d2..705f453c 100644
--- a/org.jacoco.core/src/org/jacoco/core/data/ExecutionDataStore.java
+++ b/org.jacoco.core/src/org/jacoco/core/data/ExecutionDataStore.java
@@ -13,7 +13,9 @@ package org.jacoco.core.data;
 
 import java.util.Collection;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Map;
+import java.util.Set;
 
 /**
  * In-memory data store for execution data. The data can be added through its
@@ -27,6 +29,8 @@ public final class ExecutionDataStore implements IExecutionDataVisitor {
 
 	private final Map<Long, ExecutionData> entries = new HashMap<Long, ExecutionData>();
 
+	private final Set<String> names = new HashSet<String>();
+
 	/**
 	 * Adds the given {@link ExecutionData} object into the store. If there is
 	 * already execution data with this same class id, this structure is merged
@@ -44,6 +48,7 @@ public final class ExecutionDataStore implements IExecutionDataVisitor {
 		final ExecutionData entry = entries.get(id);
 		if (entry == null) {
 			entries.put(id, data);
+			names.add(data.getName());
 		} else {
 			entry.merge(data);
 		}
@@ -96,6 +101,19 @@ public final class ExecutionDataStore implements IExecutionDataVisitor {
 	}
 
 	/**
+	 * Checks whether execution data for classes with the given name are
+	 * contained in the store.
+	 * 
+	 * @param name
+	 *            VM name
+	 * @return <code>true</code> if at least one class with the name is
+	 *         contained.
+	 */
+	public boolean contains(final String name) {
+		return names.contains(name);
+	}
+
+	/**
 	 * Returns the coverage data for the class with the given identifier. If
 	 * there is no data available under the given id a new entry is created.
 	 * 
@@ -113,6 +131,7 @@ public final class ExecutionDataStore implements IExecutionDataVisitor {
 		if (entry == null) {
 			entry = new ExecutionData(id.longValue(), name, probecount);
 			entries.put(id, entry);
+			names.add(name);
 		} else {
 			entry.assertCompatibility(id.longValue(), name, probecount);
 		}
diff --git a/org.jacoco.core/src/org/jacoco/core/internal/analysis/ClassAnalyzer.java b/org.jacoco.core/src/org/jacoco/core/internal/analysis/ClassAnalyzer.java
index 74d5da5c..8508ab18 100644
--- a/org.jacoco.core/src/org/jacoco/core/internal/analysis/ClassAnalyzer.java
+++ b/org.jacoco.core/src/org/jacoco/core/internal/analysis/ClassAnalyzer.java
@@ -24,6 +24,7 @@ import org.objectweb.asm.Opcodes;
 public class ClassAnalyzer extends ClassProbesVisitor {
 
 	private final long classid;
+	private final boolean noMatch;
 	private final boolean probes[];
 	private final StringPool stringPool;
 
@@ -34,14 +35,18 @@ public class ClassAnalyzer extends ClassProbesVisitor {
 	 * 
 	 * @param classid
 	 *            id of the class
+	 * @param noMatch
+	 *            <code>true</code> if class id does not match with execution
+	 *            data
 	 * @param probes
 	 *            execution data for this class or <code>null</code>
 	 * @param stringPool
 	 *            shared pool to minimize the number of {@link String} instances
 	 */
-	public ClassAnalyzer(final long classid, final boolean[] probes,
-			final StringPool stringPool) {
+	public ClassAnalyzer(final long classid, final boolean noMatch,
+			final boolean[] probes, final StringPool stringPool) {
 		this.classid = classid;
+		this.noMatch = noMatch;
 		this.probes = probes;
 		this.stringPool = stringPool;
 	}
@@ -61,7 +66,7 @@ public class ClassAnalyzer extends ClassProbesVisitor {
 			final String signature, final String superName,
 			final String[] interfaces) {
 		this.coverage = new ClassCoverageImpl(stringPool.get(name), classid,
-				stringPool.get(signature), stringPool.get(superName),
+				noMatch, stringPool.get(signature), stringPool.get(superName),
 				stringPool.get(interfaces));
 	}
 
diff --git a/org.jacoco.core/src/org/jacoco/core/internal/analysis/ClassCoverageImpl.java b/org.jacoco.core/src/org/jacoco/core/internal/analysis/ClassCoverageImpl.java
index 3ee8667c..1a29f24e 100644
--- a/org.jacoco.core/src/org/jacoco/core/internal/analysis/ClassCoverageImpl.java
+++ b/org.jacoco.core/src/org/jacoco/core/internal/analysis/ClassCoverageImpl.java
@@ -23,6 +23,7 @@ import org.jacoco.core.analysis.IMethodCoverage;
 public class ClassCoverageImpl extends SourceNodeImpl implements IClassCoverage {
 
 	private final long id;
+	private final boolean noMatch;
 	private final String signature;
 	private final String superName;
 	private final String[] interfaces;
@@ -36,6 +37,9 @@ public class ClassCoverageImpl extends SourceNodeImpl implements IClassCoverage
 	 *            vm name of the class
 	 * @param id
 	 *            class identifier
+	 * @param noMatch
+	 *            <code>true</code>, if class id does not match with execution
+	 *            data
 	 * @param signature
 	 *            vm signature of the class
 	 * @param superName
@@ -44,10 +48,11 @@ public class ClassCoverageImpl extends SourceNodeImpl implements IClassCoverage
 	 *            vm names of interfaces of this class
 	 */
 	public ClassCoverageImpl(final String name, final long id,
-			final String signature, final String superName,
-			final String[] interfaces) {
+			final boolean noMatch, final String signature,
+			final String superName, final String[] interfaces) {
 		super(ElementType.CLASS, name);
 		this.id = id;
+		this.noMatch = noMatch;
 		this.signature = signature;
 		this.superName = superName;
 		this.interfaces = interfaces;
@@ -87,6 +92,10 @@ public class ClassCoverageImpl extends SourceNodeImpl implements IClassCoverage
 		return id;
 	}
 
+	public boolean isNoMatch() {
+		return noMatch;
+	}
+
 	public String getSignature() {
 		return signature;
 	}
diff --git a/org.jacoco.doc/docroot/doc/changes.html b/org.jacoco.doc/docroot/doc/changes.html
index 14787b70..417f11e3 100644
--- a/org.jacoco.doc/docroot/doc/changes.html
+++ b/org.jacoco.doc/docroot/doc/changes.html
@@ -21,13 +21,18 @@
 <h2>Snapshot Build @qualified.bundle.version@ (@build.date@)</h2>
 
 <h3>New Features</h3>
+<ul>
+  <li>Warnings are logged during report generation if different versions of
+      classes are used than at runtime (GitHub <a href="https://github.com/jacoco/jacoco/issues/185">#185</a>).</li>
+</ul>
 
 <h3>Fixed Bugs</h3>
 <ul>
   <li>Skip jacoco instrumentation for mvn modules with package type ear (GitHub <a href="https://github.com/jacoco/jacoco/issues/169">#169</a>).</li>
-  <li>Align skip conditions and messages for Maven goals and give reasons (GitHub <a href="https://github.com/jacoco/jacoco/issues/171">#171</a>).
-  This includes removal of the specific skip condition for packages e.g. POMs and instead checks existence of <tt>target/classes</tt> in appropriate
-  goals.</li>
+  <li>Align skip conditions and messages for Maven goals and give reasons. This
+      includes removal of the specific skip condition for packages e.g. POMs and
+      instead checks existence of <tt>target/classes</tt> in appropriate goals
+      (GitHub <a href="https://github.com/jacoco/jacoco/issues/171">#171</a>).</li>
 </ul>
 
 <h3>API Changes</h3>
diff --git a/org.jacoco.report.test/src/org/jacoco/report/ReportStructureTestDriver.java b/org.jacoco.report.test/src/org/jacoco/report/ReportStructureTestDriver.java
index c338312c..3631ea18 100644
--- a/org.jacoco.report.test/src/org/jacoco/report/ReportStructureTestDriver.java
+++ b/org.jacoco.report.test/src/org/jacoco/report/ReportStructureTestDriver.java
@@ -74,8 +74,8 @@ public class ReportStructureTestDriver {
 		methodCoverage = m;
 
 		final ClassCoverageImpl classCoverageImpl = new ClassCoverageImpl(
-				"org/jacoco/example/FooClass", 1001, null, "java/lang/Object",
-				new String[0]);
+				"org/jacoco/example/FooClass", 1001, false, null,
+				"java/lang/Object", new String[0]);
 		classCoverageImpl.setSourceFileName("FooClass.java");
 		classCoverageImpl.addMethod(methodCoverage);
 		classCoverage = classCoverageImpl;
diff --git a/org.jacoco.report.test/src/org/jacoco/report/check/BundleCheckerTest.java b/org.jacoco.report.test/src/org/jacoco/report/check/BundleCheckerTest.java
index 743e784d..db40045e 100644
--- a/org.jacoco.report.test/src/org/jacoco/report/check/BundleCheckerTest.java
+++ b/org.jacoco.report.test/src/org/jacoco/report/check/BundleCheckerTest.java
@@ -134,8 +134,8 @@ public class BundleCheckerTest implements IViolationsOutput {
 		m.incrementMethodCounter();
 
 		final ClassCoverageImpl c = new ClassCoverageImpl(
-				"org/jacoco/example/FooClass", 1001, null, "java/lang/Object",
-				new String[0]);
+				"org/jacoco/example/FooClass", 1001, false, null,
+				"java/lang/Object", new String[0]);
 		c.setSourceFileName("FooClass.java");
 		c.addMethod(m);
 
diff --git a/org.jacoco.report.test/src/org/jacoco/report/csv/ClassRowWriterTest.java b/org.jacoco.report.test/src/org/jacoco/report/csv/ClassRowWriterTest.java
index ca80fd36..50d6e281 100644
--- a/org.jacoco.report.test/src/org/jacoco/report/csv/ClassRowWriterTest.java
+++ b/org.jacoco.report.test/src/org/jacoco/report/csv/ClassRowWriterTest.java
@@ -74,7 +74,7 @@ public class ClassRowWriterTest {
 	@Test
 	public void TestRow() throws Exception {
 		IClassCoverage node = new ClassCoverageImpl("test/package/Foo", 123,
-				null, "java/lang/Object", null) {
+				false, null, "java/lang/Object", null) {
 			{
 				instructionCounter = CounterImpl.getInstance(1, 11);
 				branchCounter = CounterImpl.getInstance(2, 22);
diff --git a/org.jacoco.report.test/src/org/jacoco/report/internal/html/page/ClassPageTest.java b/org.jacoco.report.test/src/org/jacoco/report/internal/html/page/ClassPageTest.java
index 7e2ccc73..c1ed05cf 100644
--- a/org.jacoco.report.test/src/org/jacoco/report/internal/html/page/ClassPageTest.java
+++ b/org.jacoco.report.test/src/org/jacoco/report/internal/html/page/ClassPageTest.java
@@ -35,8 +35,8 @@ public class ClassPageTest extends PageTestBase {
 	@Override
 	public void setup() throws Exception {
 		super.setup();
-		node = new ClassCoverageImpl("org/jacoco/example/Foo", 123, null,
-				"java/lang/Object", null);
+		node = new ClassCoverageImpl("org/jacoco/example/Foo", 123, false,
+				null, "java/lang/Object", null);
 		node.addMethod(new MethodCoverageImpl("a", "()V", null));
 		node.addMethod(new MethodCoverageImpl("b", "()V", null));
 		node.addMethod(new MethodCoverageImpl("c", "()V", null));
@@ -66,8 +66,8 @@ public class ClassPageTest extends PageTestBase {
 
 	@Test
 	public void testGetFileNameDefault() throws IOException {
-		IClassCoverage defaultNode = new ClassCoverageImpl("Foo", 123, null,
-				"java/lang/Object", null);
+		IClassCoverage defaultNode = new ClassCoverageImpl("Foo", 123, false,
+				null, "java/lang/Object", null);
 		page = new ClassPage(defaultNode, null, null, rootFolder, context);
 		assertEquals("Foo.html", page.getFileName());
 	}
diff --git a/org.jacoco.report.test/src/org/jacoco/report/internal/html/page/PackagePageTest.java b/org.jacoco.report.test/src/org/jacoco/report/internal/html/page/PackagePageTest.java
index af74ae4b..dd3258f1 100644
--- a/org.jacoco.report.test/src/org/jacoco/report/internal/html/page/PackagePageTest.java
+++ b/org.jacoco.report.test/src/org/jacoco/report/internal/html/page/PackagePageTest.java
@@ -59,11 +59,11 @@ public class PackagePageTest extends PageTestBase {
 	@Test
 	public void testContentsWithSource() throws Exception {
 		IClassCoverage class1 = new ClassCoverageImpl(
-				"org/jacoco/example/Foo1", 0x1000, null, "java/lang/Object",
-				null);
+				"org/jacoco/example/Foo1", 0x1000, false, null,
+				"java/lang/Object", null);
 		IClassCoverage class2 = new ClassCoverageImpl(
-				"org/jacoco/example/Foo2", 0x2000, null, "java/lang/Object",
-				null);
+				"org/jacoco/example/Foo2", 0x2000, false, null,
+				"java/lang/Object", null);
 		ISourceFileCoverage src1 = new SourceFileCoverageImpl("Src1.java",
 				"org/jacoco/example");
 		node = new PackageCoverageImpl("org/jacoco/example", Arrays.asList(
@@ -96,11 +96,11 @@ public class PackagePageTest extends PageTestBase {
 	@Test
 	public void testContentsNoSource() throws Exception {
 		IClassCoverage class1 = new ClassCoverageImpl(
-				"org/jacoco/example/Foo1", 0x1000, null, "java/lang/Object",
-				null);
+				"org/jacoco/example/Foo1", 0x1000, false, null,
+				"java/lang/Object", null);
 		IClassCoverage class2 = new ClassCoverageImpl(
-				"org/jacoco/example/Foo2", 0x2000, null, "java/lang/Object",
-				null);
+				"org/jacoco/example/Foo2", 0x2000, false, null,
+				"java/lang/Object", null);
 		node = new PackageCoverageImpl("org/jacoco/example", Arrays.asList(
 				class1, class2), Collections.<ISourceFileCoverage> emptyList());