Adds utility that checks which classes are implemented in JCL emulation

and produces JSON report

teavm-classlib/pom.xml

@@ -58,6 +58,34 @@
           </execution>
         </executions>
       </plugin>
+      <plugin>
+      <groupId>org.codehaus.mojo</groupId>
+        <artifactId>exec-maven-plugin</artifactId>
+        <version>1.2.1</version>
+        <executions>
+          <execution>
+            <goals>
+              <goal>java</goal>
+            </goals>
+            <phase>process-test-classes</phase>
+          </execution>
+        </executions>
+        <configuration>
+          <mainClass>org.teavm.classlib.impl.JCLComparisonBuilder</mainClass>
+          <arguments>
+            <argument>java.lang</argument>
+            <argument>java.lang.annotation</argument>
+            <argument>java.lang.reflect</argument>
+            <argument>java.io</argument>
+            <argument>java.net</argument>
+            <argument>java.util</argument>
+            <argument>java.util.logging</argument>
+            <argument>java.util.concurrent</argument>
+            <argument>-output</argument>
+            <argument>${project.build.directory}/jcl-report/jcl-comparision.json</argument>
+          </arguments>
+        </configuration>
+      </plugin>
     </plugins>
     <pluginManagement>
       <plugins>

teavm-classlib/src/main/java/org/teavm/classlib/impl/JCLComparisonBuilder.java

@@ -0,0 +1,121 @@
+/*
+ *  Copyright 2014 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.classlib.impl;
+
+import java.io.*;
+import java.net.URL;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.jar.JarEntry;
+import java.util.jar.JarInputStream;
+import org.objectweb.asm.ClassReader;
+import org.teavm.parsing.ClasspathClassHolderSource;
+
+/**
+ *
+ * @author Alexey Andreev
+ */
+public class JCLComparisonBuilder {
+    private static final String JAR_PREFIX = "jar:file:";
+    private static final String JAR_SUFFIX = "!/java/lang/Object.class";
+    private static final String CLASS_SUFFIX = ".class";
+    private Set<String> packages = new HashSet<>();
+    private ClassLoader classLoader = JCLComparisonBuilder.class.getClassLoader();
+    private JCLComparisonVisitor visitor;
+    private String outputFile;
+
+    public ClassLoader getClassLoader() {
+        return classLoader;
+    }
+
+    public void setClassLoader(ClassLoader classLoader) {
+        this.classLoader = classLoader;
+    }
+
+    public Set<String> getPackages() {
+        return packages;
+    }
+
+    public String getOutputFile() {
+        return outputFile;
+    }
+
+    public void setOutputFile(String outputFile) {
+        this.outputFile = outputFile;
+    }
+
+    public static void main(String[] args) throws IOException {
+        if (args.length == 0) {
+            System.err.println("Usage: package.name [package.name2 ...]");
+            System.exit(1);
+        }
+        JCLComparisonBuilder builder = new JCLComparisonBuilder();
+
+        for (int i = 0; i < args.length; ++i) {
+            if (args[i].equals("-output")) {
+                builder.setOutputFile(args[++i]);
+            } else {
+                builder.getPackages().add(args[i].replace('.', '/'));
+            }
+        }
+
+        builder.buildComparisonReport();
+    }
+
+    public void buildComparisonReport() throws IOException {
+        URL url = classLoader.getResource("java/lang/Object" + CLASS_SUFFIX);
+        String path = url.toString();
+        if (!path.startsWith(JAR_PREFIX) || !path.endsWith(JAR_SUFFIX)) {
+            throw new RuntimeException("Can't find JCL classes");
+        }
+        ClasspathClassHolderSource classSource = new ClasspathClassHolderSource(classLoader);
+        path = path.substring(JAR_PREFIX.length(), path.length() - JAR_SUFFIX.length());
+        File outDir = new File(outputFile).getParentFile();
+        if (!outDir.exists()) {
+            outDir.mkdirs();
+        }
+        try (JarInputStream jar = new JarInputStream(new FileInputStream(path));
+             PrintStream out = new PrintStream(new FileOutputStream(outputFile))) {
+            out.println("{");
+            visitor = new JCLComparisonVisitor(classSource, out);
+            while (true) {
+                JarEntry entry = jar.getNextJarEntry();
+                if (entry == null) {
+                    break;
+                }
+                if (validateName(entry.getName())) {
+                    compareClass(jar);
+                }
+                jar.closeEntry();
+            }
+            out.println();
+            out.println("}");
+        }
+    }
+
+    private boolean validateName(String name) {
+        if (!name.endsWith(CLASS_SUFFIX)) {
+            return false;
+        }
+        int slashIndex = name.lastIndexOf('/');
+        return packages.contains(name.substring(0, slashIndex));
+    }
+
+    private void compareClass(InputStream input) throws IOException {
+        ClassReader reader = new ClassReader(input);
+        reader.accept(visitor, 0);
+    }
+}

teavm-classlib/src/main/java/org/teavm/classlib/impl/JCLComparisonVisitor.java

@@ -0,0 +1,143 @@
+/*
+ *  Copyright 2014 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.classlib.impl;
+
+import java.io.PrintStream;
+import org.objectweb.asm.*;
+import org.teavm.model.*;
+import org.teavm.model.ClassReader;
+
+/**
+ *
+ * @author Alexey Andreev
+ */
+class JCLComparisonVisitor implements ClassVisitor {
+    private PrintStream out;
+    private ClassReaderSource classSource;
+    private boolean first = true;
+    private boolean firstItem;
+    private boolean pass;
+    private boolean ended;
+    private ClassReader classReader;
+
+    public JCLComparisonVisitor(ClassReaderSource classSource, PrintStream out) {
+        this.classSource = classSource;
+        this.out = out;
+    }
+
+    @Override
+    public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
+        if ((access & Opcodes.ACC_PUBLIC) == 0) {
+            return;
+        }
+        String javaName = name.replace('/', '.');
+        if (!first) {
+            out.println(",");
+        }
+        first = false;
+        out.println("    \"" + javaName + "\" : {");
+        classReader = classSource.get(javaName);
+        if (classReader == null) {
+            out.println("        \"implemented\" : false");
+            pass = true;
+        } else {
+            out.println("        \"implemented\" : true,");
+            out.println("        \"items\" : [");
+            pass = false;
+        }
+        ended = false;
+        firstItem = true;
+    }
+
+    @Override
+    public FieldVisitor visitField(int access, String name, String desc, String signature, Object value) {
+        if (pass) {
+            return null;
+        }
+        if ((access & (Opcodes.ACC_PUBLIC | Opcodes.ACC_PROTECTED)) == 0) {
+            return null;
+        }
+        if (!firstItem) {
+            out.println(",");
+        }
+        firstItem = false;
+        out.println("            {");
+        out.println("                 \"type\" : \"field\",");
+        out.println("                 \"name\" : \"" + name + "\",");
+        out.println("                 \"descriptor\" : \"" + desc + "\",");
+        FieldReader field = classReader.getField(name);
+        out.println("                 \"implemented\" : \"" + (field != null ? "true" : "false") + "\",");
+        out.print("            }");
+        return null;
+    }
+
+    @Override
+    public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
+        if (pass) {
+            return null;
+        }
+        if ((access & (Opcodes.ACC_PUBLIC | Opcodes.ACC_PROTECTED)) == 0) {
+            return null;
+        }
+        if (!firstItem) {
+            out.println(",");
+        }
+        firstItem = false;
+        out.println("            {");
+        out.println("                 \"type\" : \"method\",");
+        out.println("                 \"name\" : \"" + name + "\",");
+        out.println("                 \"descriptor\" : \"" + desc + "\",");
+        MethodReader method = classReader.getMethod(MethodDescriptor.parse(name + desc));
+        out.println("                 \"implemented\" : \"" + (method != null ? "true" : "false") + "\",");
+        out.print("            }");
+        return null;
+    }
+
+    @Override
+    public void visitSource(String source, String debug) {
+    }
+
+    @Override
+    public void visitOuterClass(String owner, String name, String desc) {
+    }
+
+    @Override
+    public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
+        return null;
+    }
+
+    @Override
+    public void visitAttribute(Attribute attr) {
+    }
+
+    @Override
+    public void visitInnerClass(String name, String outerName, String innerName, int access) {
+    }
+
+    @Override
+    public void visitEnd() {
+        if (!ended) {
+            if (!pass) {
+                if (!firstItem) {
+                    out.println();
+                }
+                out.println("        ]");
+            }
+            out.print("    }");
+            ended = true;
+        }
+    }
+}

teavm-core/src/main/java/org/teavm/parsing/ClasspathResourceMapper.java

@@ -93,7 +93,7 @@ public class ClasspathResourceMapper implements Mapper<String, ClassHolder> {
             if (name.startsWith(transformation.packageName)) {
                 int index = name.lastIndexOf('.');
                 String className = name.substring(index + 1);
-                String packageName = name.substring(0, index);
+                String packageName = index > 0 ? name.substring(0, index) : "";
                 ClassHolder classHolder = innerMapper.map(transformation.packagePrefix + packageName +
                         "." + transformation.classPrefix + className);
                 if (classHolder != null) {