Don't generate unused class names in metadata section

classlib/src/main/java/org/teavm/classlib/impl/ReflectionDependencyListener.java

@@ -57,6 +57,12 @@ public class ReflectionDependencyListener extends AbstractDependencyListener {
     private MethodReference forName = new MethodReference(Class.class, "forName", String.class, Boolean.class,
             ClassLoader.class, Class.class);
     private MethodReference forNameShort = new MethodReference(Class.class, "forName", String.class, Class.class);
+    private MethodReference fieldGetType = new MethodReference(Field.class, "getType", Class.class);
+    private MethodReference methodGetReturnType = new MethodReference(Method.class, "getReturnType", Class.class);
+    private MethodReference methodGetParameterTypes = new MethodReference(Method.class, "getParameterTypes",
+            Class[].class);
+    private MethodReference constructorGetParameterTypes = new MethodReference(Constructor.class, "getParameterTypes",
+            Class[].class);
     private boolean fieldGetHandled;
     private boolean fieldSetHandled;
     private boolean newInstanceHandled;
@@ -66,6 +72,7 @@ public class ReflectionDependencyListener extends AbstractDependencyListener {
     private Set<String> classesWithReflectableFields = new LinkedHashSet<>();
     private Set<String> classesWithReflectableMethods = new LinkedHashSet<>();
     private DependencyNode allClasses;
+    private DependencyNode typesInReflectableSignaturesNode;
 
     public ReflectionDependencyListener(List<ReflectionSupplier> reflectionSuppliers) {
         this.reflectionSuppliers = reflectionSuppliers;
@@ -74,6 +81,7 @@ public class ReflectionDependencyListener extends AbstractDependencyListener {
     @Override
     public void started(DependencyAgent agent) {
         allClasses = agent.createNode();
+        typesInReflectableSignaturesNode = agent.createNode();
     }
 
     public Set<String> getClassesWithReflectableFields() {
@@ -138,6 +146,13 @@ public class ReflectionDependencyListener extends AbstractDependencyListener {
             });
         } else if (method.getReference().equals(forName) || method.getReference().equals(forNameShort)) {
             allClasses.connect(method.getResult().getClassValueNode());
+        } else if (method.getReference().equals(fieldGetType) || method.getReference().equals(methodGetReturnType)) {
+            method.getResult().propagate(agent.getType("java.lang.Class"));
+            typesInReflectableSignaturesNode.connect(method.getResult().getClassValueNode());
+        } else if (method.getReference().equals(methodGetParameterTypes)
+                || method.getReference().equals(constructorGetParameterTypes)) {
+            method.getResult().getArrayItem().propagate(agent.getType("java.lang.Class"));
+            typesInReflectableSignaturesNode.connect(method.getResult().getArrayItem().getClassValueNode());
         }
     }
 
@@ -251,7 +266,9 @@ public class ReflectionDependencyListener extends AbstractDependencyListener {
             type = ((ValueType.Array) type).getItemType();
         }
         if (type instanceof ValueType.Object) {
-            agent.linkClass(((ValueType.Object) type).getClassName(), null);
+            String className = ((ValueType.Object) type).getClassName();
+            agent.linkClass(className, null);
+            typesInReflectableSignaturesNode.propagate(agent.getType(className));
         }
     }
 

classlib/src/main/java/org/teavm/classlib/java/lang/reflect/TConstructor.java

@@ -80,6 +80,7 @@ public class TConstructor<T> extends TAccessibleObject implements TMember {
             sb.append(' ');
         }
         sb.append(declaringClass.getName().toString()).append('(');
+        TClass<?>[] parameterTypes = getParameterTypes();
         for (int i = 0; i < parameterTypes.length; ++i) {
             if (i > 0) {
                 sb.append(',');

classlib/src/main/java/org/teavm/classlib/java/lang/reflect/TField.java

@@ -81,7 +81,7 @@ public class TField extends TAccessibleObject implements TMember {
         if (sb.length() > 0) {
             sb.append(' ');
         }
-        sb.append(type.getName()).append(' ').append(declaringClass.getName()).append(".").append(name);
+        sb.append(getType().getName()).append(' ').append(declaringClass.getName()).append(".").append(name);
         return sb.toString();
     }
 

classlib/src/main/java/org/teavm/classlib/java/lang/reflect/TMethod.java

@@ -80,8 +80,9 @@ public class TMethod extends TAccessibleObject implements TMember {
         if (sb.length() > 0) {
             sb.append(' ');
         }
-        sb.append(returnType.getName()).append(' ').append(declaringClass.getName()).append('.')
+        sb.append(getReturnType().getName()).append(' ').append(declaringClass.getName()).append('.')
                 .append(name).append('(');
+        TClass<?>[] parameterTypes = getParameterTypes();
         if (parameterTypes.length > 0) {
             sb.append(parameterTypes[0].getName());
             for (int i = 1; i < parameterTypes.length; ++i) {

core/src/main/java/org/teavm/backend/javascript/JavaScriptTarget.java

@@ -266,7 +266,8 @@ public class JavaScriptTarget implements TeaVMTarget, TeaVMJavaScriptHost {
         }
         RenderingContext renderingContext = new RenderingContext(debugEmitterToUse,
                 controller.getUnprocessedClassSource(), classes,
-                controller.getClassLoader(), controller.getServices(), controller.getProperties(), naming);
+                controller.getClassLoader(), controller.getServices(), controller.getProperties(), naming,
+                controller.getDependencyInfo());
         renderingContext.setMinifying(minifying);
         Renderer renderer = new Renderer(sourceWriter, asyncMethods, asyncFamilyMethods,
                 controller.getDiagnostics(), renderingContext);

core/src/main/java/org/teavm/backend/javascript/rendering/Renderer.java

@@ -19,6 +19,7 @@ import com.carrotsearch.hppc.ObjectIntHashMap;
 import com.carrotsearch.hppc.ObjectIntMap;
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Properties;
@@ -41,6 +42,7 @@ import org.teavm.backend.javascript.spi.GeneratorContext;
 import org.teavm.common.ServiceRepository;
 import org.teavm.debugging.information.DebugInformationEmitter;
 import org.teavm.debugging.information.DummyDebugInformationEmitter;
+import org.teavm.dependency.MethodDependencyInfo;
 import org.teavm.diagnostics.Diagnostics;
 import org.teavm.model.ClassReader;
 import org.teavm.model.ClassReaderSource;
@@ -485,6 +487,19 @@ public class Renderer implements RenderingManager {
     }
 
     private void renderClassMetadata(List<ClassNode> classes) {
+        Set<String> classesRequiringName = new HashSet<>();
+        MethodDependencyInfo getNameMethod = context.getDependencyInfo().getMethod(
+                new MethodReference(Class.class, "getName", String.class));
+        if (getNameMethod != null) {
+            classesRequiringName.addAll(Arrays.asList(getNameMethod.getVariable(0).getClassValueNode().getTypes()));
+        }
+        MethodDependencyInfo getSimpleNameMethod = context.getDependencyInfo().getMethod(
+                new MethodReference(Class.class, "getSimpleName", String.class));
+        if (getSimpleNameMethod != null) {
+            classesRequiringName.addAll(Arrays.asList(
+                    getSimpleNameMethod.getVariable(0).getClassValueNode().getTypes()));
+        }
+
         int start = writer.getOffset();
         try {
             writer.append("$rt_metadata([");
@@ -495,7 +510,14 @@ public class Renderer implements RenderingManager {
                 }
                 first = false;
                 writer.appendClass(cls.getName()).append(",").ws();
-                writer.append("\"").append(RenderingUtil.escapeString(cls.getName())).append("\",").ws();
+
+                if (classesRequiringName.contains(cls.getName())) {
+                    writer.append("\"").append(RenderingUtil.escapeString(cls.getName())).append("\"");
+                } else {
+                    writer.append("0");
+                }
+                writer.append(",").ws();
+
                 if (cls.getParentName() != null) {
                     writer.appendClass(cls.getParentName());
                 } else {

core/src/main/java/org/teavm/backend/javascript/rendering/RenderingContext.java

@@ -30,6 +30,7 @@ import org.teavm.backend.javascript.spi.InjectedBy;
 import org.teavm.backend.javascript.spi.Injector;
 import org.teavm.common.ServiceRepository;
 import org.teavm.debugging.information.DebugInformationEmitter;
+import org.teavm.dependency.DependencyInfo;
 import org.teavm.interop.PlatformMarker;
 import org.teavm.model.AnnotationReader;
 import org.teavm.model.ClassReader;
@@ -48,6 +49,7 @@ public class RenderingContext {
     private ServiceRepository services;
     private Properties properties;
     private NamingStrategy naming;
+    private DependencyInfo dependencyInfo;
     private final Deque<LocationStackEntry> locationStack = new ArrayDeque<>();
     private final Map<String, Integer> stringPoolMap = new HashMap<>();
     private final List<String> stringPool = new ArrayList<>();
@@ -58,7 +60,7 @@ public class RenderingContext {
     public RenderingContext(DebugInformationEmitter debugEmitter,
             ClassReaderSource initialClassSource, ListableClassReaderSource classSource,
             ClassLoader classLoader, ServiceRepository services, Properties properties,
-            NamingStrategy naming) {
+            NamingStrategy naming, DependencyInfo dependencyInfo) {
         this.debugEmitter = debugEmitter;
         this.initialClassSource = initialClassSource;
         this.classSource = classSource;
@@ -66,6 +68,7 @@ public class RenderingContext {
         this.services = services;
         this.properties = properties;
         this.naming = naming;
+        this.dependencyInfo = dependencyInfo;
     }
 
     public ClassReaderSource getInitialClassSource() {
@@ -92,6 +95,10 @@ public class RenderingContext {
         return naming;
     }
 
+    public DependencyInfo getDependencyInfo() {
+        return dependencyInfo;
+    }
+
     public void setMinifying(boolean minifying) {
         this.minifying = minifying;
     }

core/src/main/resources/org/teavm/backend/javascript/runtime.js

@@ -433,7 +433,8 @@ function $rt_metadata(data) {
         var cls = data[i];
         cls.$meta = {};
         var m = cls.$meta;
-        m.name = data[i + 1];
+        var className = data[i + 1];
+        m.name = className !== 0 ? className : null;
         m.binaryName = "L" + m.name + ";";
         var superclass = data[i + 2];
         m.superclass = superclass !== 0 ? superclass : null;