make/jdk/src/classes/build/tools/depend/Depend.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 package build.tools.depend;

 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.lang.annotation.Documented;
 import java.nio.charset.Charset;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
 import java.util.stream.Collectors;

 import javax.lang.model.element.AnnotationMirror;
 import javax.lang.model.element.AnnotationValue;
 import javax.lang.model.element.AnnotationValueVisitor;
 import javax.lang.model.element.Element;
 import javax.lang.model.element.ElementVisitor;
 import javax.lang.model.element.ExecutableElement;
 import javax.lang.model.element.Modifier;
 import javax.lang.model.element.ModuleElement;
 import javax.lang.model.element.ModuleElement.DirectiveVisitor;
 import javax.lang.model.element.ModuleElement.ExportsDirective;
 import javax.lang.model.element.ModuleElement.OpensDirective;
 import javax.lang.model.element.ModuleElement.ProvidesDirective;
 import javax.lang.model.element.ModuleElement.RequiresDirective;
 import javax.lang.model.element.ModuleElement.UsesDirective;
 import javax.lang.model.element.PackageElement;
 import javax.lang.model.element.QualifiedNameable;
 import javax.lang.model.element.TypeElement;
 import javax.lang.model.element.TypeParameterElement;
 import javax.lang.model.element.VariableElement;
 import javax.lang.model.type.ArrayType;
 import javax.lang.model.type.DeclaredType;
 import javax.lang.model.type.ErrorType;
 import javax.lang.model.type.ExecutableType;
 import javax.lang.model.type.IntersectionType;
 import javax.lang.model.type.NoType;
 import javax.lang.model.type.NullType;
 import javax.lang.model.type.PrimitiveType;
 import javax.lang.model.type.TypeMirror;
 import javax.lang.model.type.TypeVariable;
 import javax.lang.model.type.TypeVisitor;
 import javax.lang.model.type.UnionType;
 import javax.lang.model.type.WildcardType;
 import javax.lang.model.util.ElementFilter;
 import javax.tools.JavaFileObject;

 import com.sun.source.util.JavacTask;
 import com.sun.source.util.Plugin;
 import com.sun.source.util.TaskEvent;
 import com.sun.source.util.TaskEvent.Kind;
 import com.sun.source.util.TaskListener;
 import com.sun.source.util.TreePath;
 import com.sun.source.util.Trees;
 import javax.lang.model.element.ElementKind;

 public class Depend implements Plugin {

     @Override
     public String getName() {
         return "depend";
     }

     @Override
     public void init(JavacTask jt, String... args) {
         jt.addTaskListener(new TaskListener() {
             private final Map<ModuleElement, Set<PackageElement>> apiPackages = new HashMap<>();
             private final MessageDigest apiHash;
             {
                 try {
                     apiHash = MessageDigest.getInstance("MD5");
                 } catch (NoSuchAlgorithmException ex) {
                     throw new IllegalStateException(ex);
                 }
             }
             @Override
             public void started(TaskEvent te) {
             }

             @Override
             public void finished(TaskEvent te) {
                 if (te.getKind() == Kind.ANALYZE) {
                     if (te.getSourceFile().isNameCompatible("module-info", JavaFileObject.Kind.SOURCE)) {
                         ModuleElement mod = (ModuleElement) Trees.instance(jt).getElement(new TreePath(te.getCompilationUnit()));
                         new APIVisitor(apiHash).visit(mod);
                     } else if (te.getSourceFile().isNameCompatible("package-info", JavaFileObject.Kind.SOURCE)) {
                         //ignore - cannot contain important changes (?)
                     } else {
                         TypeElement clazz = te.getTypeElement();
                         ModuleElement mod = jt.getElements().getModuleOf(clazz);
                         Set<PackageElement> thisModulePackages = apiPackages.computeIfAbsent(mod, m -> {
                             return ElementFilter.exportsIn(mod.getDirectives())
                                                 .stream()
                                                 .map(ed -> ed.getPackage())
                                                 .collect(Collectors.toSet());
                         });
                         if (thisModulePackages.contains(jt.getElements().getPackageOf(clazz))) {
                             new APIVisitor(apiHash).visit(clazz);
                         }
                     }
                 }
                 if (te.getKind() == Kind.COMPILATION) {
                     String previousSignature = null;
                     File digestFile = new File(args[0]);
                     try (InputStream in = new FileInputStream(digestFile)) {
                         previousSignature = new String(in.readAllBytes(), "UTF-8");
                     } catch (IOException ex) {
                         //ignore
                     }
                     String currentSignature = Depend.this.toString(apiHash.digest());
                     if (!Objects.equals(previousSignature, currentSignature)) {
                         digestFile.getParentFile().mkdirs();
                         try (OutputStream out = new FileOutputStream(digestFile)) {
                             out.write(currentSignature.getBytes("UTF-8"));
                         } catch (IOException ex) {
                             throw new IllegalStateException(ex);
                         }
                     }
                 }
             }
         });
     }

     private String toString(byte[] digest) {
         StringBuilder result = new StringBuilder();

         for (byte b : digest) {
             result.append(String.format("%X", b));
         }

         return result.toString();
     }

     private static final class APIVisitor implements ElementVisitor<Void, Void>,
                                                      TypeVisitor<Void, Void>,
                                                      AnnotationValueVisitor<Void, Void>,
                                                      DirectiveVisitor<Void, Void> {

         private final MessageDigest apiHash;
         private final Charset utf8;

         public APIVisitor(MessageDigest apiHash) {
             this.apiHash = apiHash;
             utf8 = Charset.forName("UTF-8");
         }

         public Void visit(Iterable<? extends Element> list, Void p) {
             list.forEach(e -> visit(e, p));
             return null;
         }

         private void update(CharSequence data) {
             apiHash.update(data.toString().getBytes(utf8));
         }

         private void visit(Iterable<? extends TypeMirror> types) {
             for (TypeMirror type : types) {
                 visit(type);
             }
         }

         private void updateAnnotation(AnnotationMirror am) {
             update("@");
             visit(am.getAnnotationType());
             am.getElementValues()
               .keySet()
               .stream()
               .sorted((ee1, ee2) -> ee1.getSimpleName().toString().compareTo(ee2.getSimpleName().toString()))
               .forEach(ee -> {
                   visit(ee);
                   visit(am.getElementValues().get(ee));
               });
         }

         private void updateAnnotations(Iterable<? extends AnnotationMirror> annotations) {
             for (AnnotationMirror am : annotations) {
                 if (am.getAnnotationType().asElement().getAnnotation(Documented.class) == null)
                     continue;
                 updateAnnotation(am);
             }
         }

         @Override
         public Void visit(Element e, Void p) {
             if (e.getKind() != ElementKind.MODULE &&
                 !e.getModifiers().contains(Modifier.PUBLIC) &&
                 !e.getModifiers().contains(Modifier.PROTECTED)) {
                 return null;
             }
             update(e.getKind().name());
             update(e.getModifiers().stream()
                                    .map(mod -> mod.name())
                                    .collect(Collectors.joining(",", "[", "]")));
             update(e.getSimpleName());
             updateAnnotations(e.getAnnotationMirrors());
             return e.accept(this, p);
         }

         @Override
         public Void visit(Element e) {
             return visit(e, null);
         }

         @Override
         public Void visitModule(ModuleElement e, Void p) {
             update(String.valueOf(e.isOpen()));
             update(e.getQualifiedName());
             e.getDirectives()
              .stream()
              .forEach(d -> d.accept(this, null));
             return null;
         }

         @Override
         public Void visitPackage(PackageElement e, Void p) {
             throw new UnsupportedOperationException("Should not get here.");
         }

         @Override
         public Void visitType(TypeElement e, Void p) {
             visit(e.getTypeParameters(), p);
             visit(e.getSuperclass());
             visit(e.getInterfaces());
             visit(e.getEnclosedElements(), p);
             return null;
         }

         @Override
         public Void visitVariable(VariableElement e, Void p) {
             visit(e.asType());
             update(String.valueOf(e.getConstantValue()));
             return null;
         }

         @Override
         public Void visitExecutable(ExecutableElement e, Void p) {
             update("<");
             visit(e.getTypeParameters(), p);
             update(">");
             visit(e.getReturnType());
             update("(");
             visit(e.getParameters(), p);
             update(")");
             visit(e.getThrownTypes());
             update(String.valueOf(e.getDefaultValue()));
             update(String.valueOf(e.isVarArgs()));
             return null;
         }

         @Override
         public Void visitTypeParameter(TypeParameterElement e, Void p) {
             visit(e.getBounds());
             return null;
         }

         @Override
         public Void visitUnknown(Element e, Void p) {
             throw new UnsupportedOperationException("Not supported.");
         }

         @Override
         public Void visit(TypeMirror t, Void p) {
             if (t == null) {
                 update("null");
                 return null;
             }
             update(t.getKind().name());
             updateAnnotations(t.getAnnotationMirrors());
             t.accept(this, p);
             return null;
         }

         @Override
         public Void visitPrimitive(PrimitiveType t, Void p) {
             return null; //done
         }

         @Override
         public Void visitNull(NullType t, Void p) {
             return null; //done
         }

         @Override
         public Void visitArray(ArrayType t, Void p) {
             visit(t.getComponentType());
             update("[]");
             return null;
         }

         @Override
         public Void visitDeclared(DeclaredType t, Void p) {
             update(((QualifiedNameable) t.asElement()).getQualifiedName());
             update("<");
             visit(t.getTypeArguments());
             update(">");
             return null;
         }

         @Override
         public Void visitError(ErrorType t, Void p) {
             return visitDeclared(t, p);
         }

         private final Set<Element> seenVariables = new HashSet<>();

         @Override
         public Void visitTypeVariable(TypeVariable t, Void p) {
             Element decl = t.asElement();
             if (!seenVariables.add(decl)) {
                 return null;
             }
             visit(decl, null);
             visit(t.getLowerBound(), null);
             visit(t.getUpperBound(), null);
             seenVariables.remove(decl);
             return null;
         }

         @Override
         public Void visitWildcard(WildcardType t, Void p) {
             visit(t.getSuperBound());
             visit(t.getExtendsBound());
             return null;
         }

         @Override
         public Void visitExecutable(ExecutableType t, Void p) {
             throw new UnsupportedOperationException("Not supported.");
         }

         @Override
         public Void visitNoType(NoType t, Void p) {
             return null;//done
         }

         @Override
         public Void visitUnknown(TypeMirror t, Void p) {
             throw new UnsupportedOperationException("Not supported.");
         }

         @Override
         public Void visitUnion(UnionType t, Void p) {
             update("(");
             visit(t.getAlternatives());
             update(")");
             return null;
         }

         @Override
         public Void visitIntersection(IntersectionType t, Void p) {
             update("(");
             visit(t.getBounds());
             update(")");
             return null;
         }

         @Override
         public Void visit(AnnotationValue av, Void p) {
             return av.accept(this, p);
         }

         @Override
         public Void visitBoolean(boolean b, Void p) {
             update(String.valueOf(b));
             return null;
         }

         @Override
         public Void visitByte(byte b, Void p) {
             update(String.valueOf(b));
             return null;
         }

         @Override
         public Void visitChar(char c, Void p) {
             update(String.valueOf(c));
             return null;
         }

         @Override
         public Void visitDouble(double d, Void p) {
             update(String.valueOf(d));
             return null;
         }

         @Override
         public Void visitFloat(float f, Void p) {
             update(String.valueOf(f));
             return null;
         }

         @Override
         public Void visitInt(int i, Void p) {
             update(String.valueOf(i));
             return null;
         }

         @Override
         public Void visitLong(long i, Void p) {
             update(String.valueOf(i));
             return null;
         }

         @Override
         public Void visitShort(short s, Void p) {
             update(String.valueOf(s));
             return null;
         }

         @Override
         public Void visitString(String s, Void p) {
             update(s);
             return null;
         }

         @Override
         public Void visitType(TypeMirror t, Void p) {
             return visit(t);
         }

         @Override
         public Void visitEnumConstant(VariableElement c, Void p) {
             return visit(c);
         }

         @Override
         public Void visitAnnotation(AnnotationMirror a, Void p) {
             updateAnnotation(a);
             return null;
         }

         @Override
         public Void visitArray(List<? extends AnnotationValue> vals, Void p) {
             update("(");
             for (AnnotationValue av : vals) {
                 visit(av);
             }
             update(")");
             return null;
         }

         @Override
         public Void visitUnknown(AnnotationValue av, Void p) {
             throw new UnsupportedOperationException("Not supported.");
         }

         @Override
         public Void visitRequires(RequiresDirective d, Void p) {
             update("RequiresDirective");
             update(String.valueOf(d.isStatic()));
             update(String.valueOf(d.isTransitive()));
             update(d.getDependency().getQualifiedName());
             return null;
         }

         @Override
         public Void visitExports(ExportsDirective d, Void p) {
             update("ExportsDirective");
             update(d.getPackage().getQualifiedName());
             if (d.getTargetModules() != null) {
                 for (ModuleElement me : d.getTargetModules()) {
                     update(me.getQualifiedName());
                 }
             } else {
                 update("<none>");
             }
             return null;
         }

         @Override
         public Void visitOpens(OpensDirective d, Void p) {
             update("OpensDirective");
             update(d.getPackage().getQualifiedName());
             if (d.getTargetModules() != null) {
                 for (ModuleElement me : d.getTargetModules()) {
                     update(me.getQualifiedName());
                 }
             } else {
                 update("<none>");
             }
             return null;
         }

         @Override
         public Void visitUses(UsesDirective d, Void p) {
             update("UsesDirective");
             update(d.getService().getQualifiedName());
             return null;
         }

         @Override
         public Void visitProvides(ProvidesDirective d, Void p) {
             update("ProvidesDirective");
             update(d.getService().getQualifiedName());
             update("(");
             for (TypeElement impl : d.getImplementations()) {
                 update(impl.getQualifiedName());
             }
             update(")");
             return null;
         }

     }
 }
	/*
	* Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/
	package build.tools.depend;

	import java.io.File;
	import java.io.FileInputStream;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.OutputStream;
	import java.lang.annotation.Documented;
	import java.nio.charset.Charset;
	import java.security.MessageDigest;
	import java.security.NoSuchAlgorithmException;
	import java.util.Arrays;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Map;
	import java.util.Objects;
	import java.util.Set;
	import java.util.stream.Collectors;

	import javax.lang.model.element.AnnotationMirror;
	import javax.lang.model.element.AnnotationValue;
	import javax.lang.model.element.AnnotationValueVisitor;
	import javax.lang.model.element.Element;
	import javax.lang.model.element.ElementVisitor;
	import javax.lang.model.element.ExecutableElement;
	import javax.lang.model.element.Modifier;
	import javax.lang.model.element.ModuleElement;
	import javax.lang.model.element.ModuleElement.DirectiveVisitor;
	import javax.lang.model.element.ModuleElement.ExportsDirective;
	import javax.lang.model.element.ModuleElement.OpensDirective;
	import javax.lang.model.element.ModuleElement.ProvidesDirective;
	import javax.lang.model.element.ModuleElement.RequiresDirective;
	import javax.lang.model.element.ModuleElement.UsesDirective;
	import javax.lang.model.element.PackageElement;
	import javax.lang.model.element.QualifiedNameable;
	import javax.lang.model.element.TypeElement;
	import javax.lang.model.element.TypeParameterElement;
	import javax.lang.model.element.VariableElement;
	import javax.lang.model.type.ArrayType;
	import javax.lang.model.type.DeclaredType;
	import javax.lang.model.type.ErrorType;
	import javax.lang.model.type.ExecutableType;
	import javax.lang.model.type.IntersectionType;
	import javax.lang.model.type.NoType;
	import javax.lang.model.type.NullType;
	import javax.lang.model.type.PrimitiveType;
	import javax.lang.model.type.TypeMirror;
	import javax.lang.model.type.TypeVariable;
	import javax.lang.model.type.TypeVisitor;
	import javax.lang.model.type.UnionType;
	import javax.lang.model.type.WildcardType;
	import javax.lang.model.util.ElementFilter;
	import javax.tools.JavaFileObject;

	import com.sun.source.util.JavacTask;
	import com.sun.source.util.Plugin;
	import com.sun.source.util.TaskEvent;
	import com.sun.source.util.TaskEvent.Kind;
	import com.sun.source.util.TaskListener;
	import com.sun.source.util.TreePath;
	import com.sun.source.util.Trees;
	import javax.lang.model.element.ElementKind;

	public class Depend implements Plugin {

	@Override
	public String getName() {
	return "depend";
	}

	@Override
	public void init(JavacTask jt, String... args) {
	jt.addTaskListener(new TaskListener() {
	private final Map<ModuleElement, Set<PackageElement>> apiPackages = new HashMap<>();
	private final MessageDigest apiHash;
	{
	try {
	apiHash = MessageDigest.getInstance("MD5");
	} catch (NoSuchAlgorithmException ex) {
	throw new IllegalStateException(ex);
	}
	}
	@Override
	public void started(TaskEvent te) {
	}

	@Override
	public void finished(TaskEvent te) {
	if (te.getKind() == Kind.ANALYZE) {
	if (te.getSourceFile().isNameCompatible("module-info", JavaFileObject.Kind.SOURCE)) {
	ModuleElement mod = (ModuleElement) Trees.instance(jt).getElement(new TreePath(te.getCompilationUnit()));
	new APIVisitor(apiHash).visit(mod);
	} else if (te.getSourceFile().isNameCompatible("package-info", JavaFileObject.Kind.SOURCE)) {
	//ignore - cannot contain important changes (?)
	} else {
	TypeElement clazz = te.getTypeElement();
	ModuleElement mod = jt.getElements().getModuleOf(clazz);
	Set<PackageElement> thisModulePackages = apiPackages.computeIfAbsent(mod, m -> {
	return ElementFilter.exportsIn(mod.getDirectives())
	.stream()
	.map(ed -> ed.getPackage())
	.collect(Collectors.toSet());
	});
	if (thisModulePackages.contains(jt.getElements().getPackageOf(clazz))) {
	new APIVisitor(apiHash).visit(clazz);
	}
	}
	}
	if (te.getKind() == Kind.COMPILATION) {
	String previousSignature = null;
	File digestFile = new File(args[0]);
	try (InputStream in = new FileInputStream(digestFile)) {
	previousSignature = new String(in.readAllBytes(), "UTF-8");
	} catch (IOException ex) {
	//ignore
	}
	String currentSignature = Depend.this.toString(apiHash.digest());
	if (!Objects.equals(previousSignature, currentSignature)) {
	digestFile.getParentFile().mkdirs();
	try (OutputStream out = new FileOutputStream(digestFile)) {
	out.write(currentSignature.getBytes("UTF-8"));
	} catch (IOException ex) {
	throw new IllegalStateException(ex);
	}
	}
	}
	}
	});
	}

	private String toString(byte[] digest) {
	StringBuilder result = new StringBuilder();

	for (byte b : digest) {
	result.append(String.format("%X", b));
	}

	return result.toString();
	}

	private static final class APIVisitor implements ElementVisitor<Void, Void>,
	TypeVisitor<Void, Void>,
	AnnotationValueVisitor<Void, Void>,
	DirectiveVisitor<Void, Void> {

	private final MessageDigest apiHash;
	private final Charset utf8;

	public APIVisitor(MessageDigest apiHash) {
	this.apiHash = apiHash;
	utf8 = Charset.forName("UTF-8");
	}

	public Void visit(Iterable<? extends Element> list, Void p) {
	list.forEach(e -> visit(e, p));
	return null;
	}

	private void update(CharSequence data) {
	apiHash.update(data.toString().getBytes(utf8));
	}

	private void visit(Iterable<? extends TypeMirror> types) {
	for (TypeMirror type : types) {
	visit(type);
	}
	}

	private void updateAnnotation(AnnotationMirror am) {
	update("@");
	visit(am.getAnnotationType());
	am.getElementValues()
	.keySet()
	.stream()
	.sorted((ee1, ee2) -> ee1.getSimpleName().toString().compareTo(ee2.getSimpleName().toString()))
	.forEach(ee -> {
	visit(ee);
	visit(am.getElementValues().get(ee));
	});
	}

	private void updateAnnotations(Iterable<? extends AnnotationMirror> annotations) {
	for (AnnotationMirror am : annotations) {
	if (am.getAnnotationType().asElement().getAnnotation(Documented.class) == null)
	continue;
	updateAnnotation(am);
	}
	}

	@Override
	public Void visit(Element e, Void p) {
	if (e.getKind() != ElementKind.MODULE &&
	!e.getModifiers().contains(Modifier.PUBLIC) &&
	!e.getModifiers().contains(Modifier.PROTECTED)) {
	return null;
	}
	update(e.getKind().name());
	update(e.getModifiers().stream()
	.map(mod -> mod.name())
	.collect(Collectors.joining(",", "[", "]")));
	update(e.getSimpleName());
	updateAnnotations(e.getAnnotationMirrors());
	return e.accept(this, p);
	}

	@Override
	public Void visit(Element e) {
	return visit(e, null);
	}

	@Override
	public Void visitModule(ModuleElement e, Void p) {
	update(String.valueOf(e.isOpen()));
	update(e.getQualifiedName());
	e.getDirectives()
	.stream()
	.forEach(d -> d.accept(this, null));
	return null;
	}

	@Override
	public Void visitPackage(PackageElement e, Void p) {
	throw new UnsupportedOperationException("Should not get here.");
	}

	@Override
	public Void visitType(TypeElement e, Void p) {
	visit(e.getTypeParameters(), p);
	visit(e.getSuperclass());
	visit(e.getInterfaces());
	visit(e.getEnclosedElements(), p);
	return null;
	}

	@Override
	public Void visitVariable(VariableElement e, Void p) {
	visit(e.asType());
	update(String.valueOf(e.getConstantValue()));
	return null;
	}

	@Override
	public Void visitExecutable(ExecutableElement e, Void p) {
	update("<");
	visit(e.getTypeParameters(), p);
	update(">");
	visit(e.getReturnType());
	update("(");
	visit(e.getParameters(), p);
	update(")");
	visit(e.getThrownTypes());
	update(String.valueOf(e.getDefaultValue()));
	update(String.valueOf(e.isVarArgs()));
	return null;
	}

	@Override
	public Void visitTypeParameter(TypeParameterElement e, Void p) {
	visit(e.getBounds());
	return null;
	}

	@Override
	public Void visitUnknown(Element e, Void p) {
	throw new UnsupportedOperationException("Not supported.");
	}

	@Override
	public Void visit(TypeMirror t, Void p) {
	if (t == null) {
	update("null");
	return null;
	}
	update(t.getKind().name());
	updateAnnotations(t.getAnnotationMirrors());
	t.accept(this, p);
	return null;
	}

	@Override
	public Void visitPrimitive(PrimitiveType t, Void p) {
	return null; //done
	}

	@Override
	public Void visitNull(NullType t, Void p) {
	return null; //done
	}

	@Override
	public Void visitArray(ArrayType t, Void p) {
	visit(t.getComponentType());
	update("[]");
	return null;
	}

	@Override
	public Void visitDeclared(DeclaredType t, Void p) {
	update(((QualifiedNameable) t.asElement()).getQualifiedName());
	update("<");
	visit(t.getTypeArguments());
	update(">");
	return null;
	}

	@Override
	public Void visitError(ErrorType t, Void p) {
	return visitDeclared(t, p);
	}

	private final Set<Element> seenVariables = new HashSet<>();

	@Override
	public Void visitTypeVariable(TypeVariable t, Void p) {
	Element decl = t.asElement();
	if (!seenVariables.add(decl)) {
	return null;
	}
	visit(decl, null);
	visit(t.getLowerBound(), null);
	visit(t.getUpperBound(), null);
	seenVariables.remove(decl);
	return null;
	}

	@Override
	public Void visitWildcard(WildcardType t, Void p) {
	visit(t.getSuperBound());
	visit(t.getExtendsBound());
	return null;
	}

	@Override
	public Void visitExecutable(ExecutableType t, Void p) {
	throw new UnsupportedOperationException("Not supported.");
	}

	@Override
	public Void visitNoType(NoType t, Void p) {
	return null;//done
	}

	@Override
	public Void visitUnknown(TypeMirror t, Void p) {
	throw new UnsupportedOperationException("Not supported.");
	}

	@Override
	public Void visitUnion(UnionType t, Void p) {
	update("(");
	visit(t.getAlternatives());
	update(")");
	return null;
	}

	@Override
	public Void visitIntersection(IntersectionType t, Void p) {
	update("(");
	visit(t.getBounds());
	update(")");
	return null;
	}

	@Override
	public Void visit(AnnotationValue av, Void p) {
	return av.accept(this, p);
	}

	@Override
	public Void visitBoolean(boolean b, Void p) {
	update(String.valueOf(b));
	return null;
	}

	@Override
	public Void visitByte(byte b, Void p) {
	update(String.valueOf(b));
	return null;
	}

	@Override
	public Void visitChar(char c, Void p) {
	update(String.valueOf(c));
	return null;
	}

	@Override
	public Void visitDouble(double d, Void p) {
	update(String.valueOf(d));
	return null;
	}

	@Override
	public Void visitFloat(float f, Void p) {
	update(String.valueOf(f));
	return null;
	}

	@Override
	public Void visitInt(int i, Void p) {
	update(String.valueOf(i));
	return null;
	}

	@Override
	public Void visitLong(long i, Void p) {
	update(String.valueOf(i));
	return null;
	}

	@Override
	public Void visitShort(short s, Void p) {
	update(String.valueOf(s));
	return null;
	}

	@Override
	public Void visitString(String s, Void p) {
	update(s);
	return null;
	}

	@Override
	public Void visitType(TypeMirror t, Void p) {
	return visit(t);
	}

	@Override
	public Void visitEnumConstant(VariableElement c, Void p) {
	return visit(c);
	}

	@Override
	public Void visitAnnotation(AnnotationMirror a, Void p) {
	updateAnnotation(a);
	return null;
	}

	@Override
	public Void visitArray(List<? extends AnnotationValue> vals, Void p) {
	update("(");
	for (AnnotationValue av : vals) {
	visit(av);
	}
	update(")");
	return null;
	}

	@Override
	public Void visitUnknown(AnnotationValue av, Void p) {
	throw new UnsupportedOperationException("Not supported.");
	}

	@Override
	public Void visitRequires(RequiresDirective d, Void p) {
	update("RequiresDirective");
	update(String.valueOf(d.isStatic()));
	update(String.valueOf(d.isTransitive()));
	update(d.getDependency().getQualifiedName());
	return null;
	}

	@Override
	public Void visitExports(ExportsDirective d, Void p) {
	update("ExportsDirective");
	update(d.getPackage().getQualifiedName());
	if (d.getTargetModules() != null) {
	for (ModuleElement me : d.getTargetModules()) {
	update(me.getQualifiedName());
	}
	} else {
	update("<none>");
	}
	return null;
	}

	@Override
	public Void visitOpens(OpensDirective d, Void p) {
	update("OpensDirective");
	update(d.getPackage().getQualifiedName());
	if (d.getTargetModules() != null) {
	for (ModuleElement me : d.getTargetModules()) {
	update(me.getQualifiedName());
	}
	} else {
	update("<none>");
	}
	return null;
	}

	@Override
	public Void visitUses(UsesDirective d, Void p) {
	update("UsesDirective");
	update(d.getService().getQualifiedName());
	return null;
	}

	@Override
	public Void visitProvides(ProvidesDirective d, Void p) {
	update("ProvidesDirective");
	update(d.getService().getQualifiedName());
	update("(");
	for (TypeElement impl : d.getImplementations()) {
	update(impl.getQualifiedName());
	}
	update(")");
	return null;
	}

	}
	}