/*
* Copyright (c) 2009, 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.
*/
import java.io.*;
import java.util.*;
import javax.tools.JavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.StandardLocation;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.DirectoryScanner;
import org.apache.tools.ant.taskdefs.MatchingTask;
import org.apache.tools.ant.types.Path;
import org.apache.tools.ant.types.Reference;
import com.sun.source.tree.CompilationUnitTree;
import com.sun.source.util.JavacTask;
import com.sun.tools.javac.api.JavacTool;
import com.sun.tools.javac.code.Flags;
import com.sun.tools.javac.code.TypeTags;
import com.sun.tools.javac.tree.JCTree;
import com.sun.tools.javac.tree.JCTree.JCCompilationUnit;
import com.sun.tools.javac.tree.JCTree.JCFieldAccess;
import com.sun.tools.javac.tree.JCTree.JCIdent;
import com.sun.tools.javac.tree.JCTree.JCImport;
import com.sun.tools.javac.tree.JCTree.JCLiteral;
import com.sun.tools.javac.tree.JCTree.JCMethodDecl;
import com.sun.tools.javac.tree.JCTree.JCModifiers;
import com.sun.tools.javac.tree.JCTree.JCVariableDecl;
import com.sun.tools.javac.tree.Pretty;
import com.sun.tools.javac.tree.TreeMaker;
import com.sun.tools.javac.tree.TreeScanner;
import com.sun.tools.javac.tree.TreeTranslator;
import com.sun.tools.javac.util.Context;
import com.sun.tools.javac.util.ListBuffer;
import com.sun.tools.javac.util.Name;
import javax.tools.JavaFileManager;
/**
* Generate stub source files by removing implementation details from input files.
*
* This is a special purpose stub generator, specific to the needs of generating
* stub files for JDK 7 API that are needed to compile langtools files that depend
* on that API. The stub generator works by removing as much of the API source code
* as possible without affecting the public signature, in order to reduce the
* transitive closure of the API being referenced. The resulting stubs can be
* put on the langtools sourcepath with -implicit:none to compile the langtools
* files that depend on the JDK 7 API.
*
* Usage:
* genstubs -s <outdir> -sourcepath <path> <classnames>
*
* The specified class names are looked up on the sourcepath, and corresponding
* stubs are written to the source output directory.
*
* Classes are parsed into javac ASTs, then processed with a javac TreeTranslator
* to remove implementation details, and written out in the source output directory.
* Documentation comments and annotations are removed. Method bodies are removed
* and methods are marked native. Private and package-private field definitions
* have their initializers replace with 0, 0.0, false, null as appropriate.
*
* An Ant task, Main$Ant is also provided. Files are specified with an implicit
* fileset, using srcdir as a base directory. The set of files to be included
* is specified with an includes attribute or nested <includes> set. However,
* unlike a normal fileset, an empty includes attribute means "no files" instead
* of "all files". The Ant task also accepts "fork=true" and classpath attribute
* or nested <classpath> element to run GenStubs in a separate VM with the specified
* path. This is likely necessary if a JDK 7 parser is required to read the
* JDK 7 input files.
*/
public class GenStubs {
static class Fault extends Exception {
private static final long serialVersionUID = 0;
Fault(String message) {
super(message);
}
Fault(String message, Throwable cause) {
super(message);
initCause(cause);
}
}
public static void main(String[] args) {
boolean ok = new GenStubs().run(args);
if (!ok)
System.exit(1);
}
boolean run(String... args) {
File outdir = null;
String sourcepath = null;
List<String> classes = new ArrayList<String>();
for (ListIterator<String> iter = Arrays.asList(args).listIterator(); iter.hasNext(); ) {
String arg = iter.next();
if (arg.equals("-s") && iter.hasNext())
outdir = new File(iter.next());
else if (arg.equals("-sourcepath") && iter.hasNext())
sourcepath = iter.next();
else if (arg.startsWith("-"))
throw new IllegalArgumentException(arg);
else {
classes.add(arg);
while (iter.hasNext())
classes.add(iter.next());
}
}
return run(sourcepath, outdir, classes);
}
boolean run(String sourcepath, File outdir, List<String> classes) {
//System.err.println("run: sourcepath:" + sourcepath + " outdir:" + outdir + " classes:" + classes);
if (sourcepath == null)
throw new IllegalArgumentException("sourcepath not set");
if (outdir == null)
throw new IllegalArgumentException("source output dir not set");
JavacTool tool = JavacTool.create();
StandardJavaFileManager fm = tool.getStandardFileManager(null, null, null);
try {
fm.setLocation(StandardLocation.SOURCE_OUTPUT, Collections.singleton(outdir));
fm.setLocation(StandardLocation.SOURCE_PATH, splitPath(sourcepath));
List<JavaFileObject> files = new ArrayList<JavaFileObject>();
for (String c: classes) {
JavaFileObject fo = fm.getJavaFileForInput(
StandardLocation.SOURCE_PATH, c, JavaFileObject.Kind.SOURCE);
if (fo == null)
error("class not found: " + c);
else
files.add(fo);
}
JavacTask t = tool.getTask(null, fm, null, null, null, files);
Iterable<? extends CompilationUnitTree> trees = t.parse();
for (CompilationUnitTree tree: trees) {
makeStub(fm, tree);
}
} catch (IOException e) {
error("IO error " + e, e);
}
return (errors == 0);
}
void makeStub(StandardJavaFileManager fm, CompilationUnitTree tree) throws IOException {
CompilationUnitTree tree2 = new StubMaker().translate(tree);
CompilationUnitTree tree3 = new ImportCleaner(fm).removeRedundantImports(tree2);
String className = fm.inferBinaryName(StandardLocation.SOURCE_PATH, tree.getSourceFile());
JavaFileObject fo = fm.getJavaFileForOutput(StandardLocation.SOURCE_OUTPUT,
className, JavaFileObject.Kind.SOURCE, null);
// System.err.println("Writing " + className + " to " + fo.getName());
Writer out = fo.openWriter();
try {
new Pretty(out, true).printExpr((JCTree) tree3);
} finally {
out.close();
}
}
List<File> splitPath(String path) {
List<File> list = new ArrayList<File>();
for (String p: path.split(File.pathSeparator)) {
if (p.length() > 0)
list.add(new File(p));
}
return list;
}
void error(String message) {
System.err.println(message);
errors++;
}
void error(String message, Throwable cause) {
error(message);
}
int errors;
class StubMaker extends TreeTranslator {
CompilationUnitTree translate(CompilationUnitTree tree) {
return super.translate((JCCompilationUnit) tree);
}
/**
* compilation units: remove javadoc comments
* -- required, in order to remove @deprecated tags, since we
* (separately) remove all annotations, including @Deprecated
*/
public void visitTopLevel(JCCompilationUnit tree) {
super.visitTopLevel(tree);
tree.docComments = Collections.emptyMap();
}
/**
* methods: remove method bodies, make methods native
*/
@Override
public void visitMethodDef(JCMethodDecl tree) {
tree.mods = translate(tree.mods);
tree.restype = translate(tree.restype);
tree.typarams = translateTypeParams(tree.typarams);
tree.params = translateVarDefs(tree.params);
tree.thrown = translate(tree.thrown);
if (tree.restype != null && tree.body != null) {
tree.mods.flags |= Flags.NATIVE;
tree.body = null;
}
result = tree;
}
/**
* modifiers: remove annotations
*/
@Override
public void visitModifiers(JCModifiers tree) {
tree.annotations = com.sun.tools.javac.util.List.nil();
result = tree;
}
/**
* field definitions: replace initializers with 0, 0.0, false etc
* when possible -- i.e. leave public, protected initializers alone
*/
@Override
public void visitVarDef(JCVariableDecl tree) {
tree.mods = translate(tree.mods);
tree.vartype = translate(tree.vartype);
if (tree.init != null) {
if ((tree.mods.flags & (Flags.PUBLIC | Flags.PROTECTED)) != 0)
tree.init = translate(tree.init);
else {
String t = tree.vartype.toString();
if (t.equals("boolean"))
tree.init = new JCLiteral(TypeTags.BOOLEAN, 0) { };
else if (t.equals("byte"))
tree.init = new JCLiteral(TypeTags.BYTE, 0) { };
else if (t.equals("char"))
tree.init = new JCLiteral(TypeTags.CHAR, 0) { };
else if (t.equals("double"))
tree.init = new JCLiteral(TypeTags.DOUBLE, 0.d) { };
else if (t.equals("float"))
tree.init = new JCLiteral(TypeTags.FLOAT, 0.f) { };
else if (t.equals("int"))
tree.init = new JCLiteral(TypeTags.INT, 0) { };
else if (t.equals("long"))
tree.init = new JCLiteral(TypeTags.LONG, 0) { };
else if (t.equals("short"))
tree.init = new JCLiteral(TypeTags.SHORT, 0) { };
else
tree.init = new JCLiteral(TypeTags.BOT, null) { };
}
}
result = tree;
}
}
class ImportCleaner extends TreeScanner {
private Set<Name> names = new HashSet<Name>();
private TreeMaker m;
ImportCleaner(JavaFileManager fm) {
// ImportCleaner itself doesn't require a filemanager, but instantiating
// a TreeMaker does, indirectly (via ClassReader, sigh)
Context c = new Context();
c.put(JavaFileManager.class, fm);
m = TreeMaker.instance(c);
}
CompilationUnitTree removeRedundantImports(CompilationUnitTree t) {
JCCompilationUnit tree = (JCCompilationUnit) t;
tree.accept(this);
ListBuffer<JCTree> defs = new ListBuffer<JCTree>();
for (JCTree def: tree.defs) {
if (def.getTag() == JCTree.IMPORT) {
JCImport imp = (JCImport) def;
if (imp.qualid.getTag() == JCTree.SELECT) {
JCFieldAccess qualid = (JCFieldAccess) imp.qualid;
if (!qualid.name.toString().equals("*")
&& !names.contains(qualid.name)) {
continue;
}
}
}
defs.add(def);
}
return m.TopLevel(tree.packageAnnotations, tree.pid, defs.toList());
}
@Override
public void visitImport(JCImport tree) { } // ignore names found in imports
@Override
public void visitIdent(JCIdent tree) {
names.add(tree.name);
}
@Override
public void visitSelect(JCFieldAccess tree) {
super.visitSelect(tree);
names.add(tree.name);
}
}
//---------- Ant Invocation ------------------------------------------------
public static class Ant extends MatchingTask {
private File srcDir;
private File destDir;
private boolean fork;
private Path classpath;
private String includes;
public void setSrcDir(File dir) {
this.srcDir = dir;
}
public void setDestDir(File dir) {
this.destDir = dir;
}
public void setFork(boolean v) {
this.fork = v;
}
public void setClasspath(Path cp) {
if (classpath == null)
classpath = cp;
else
classpath.append(cp);
}
public Path createClasspath() {
if (classpath == null) {
classpath = new Path(getProject());
}
return classpath.createPath();
}
public void setClasspathRef(Reference r) {
createClasspath().setRefid(r);
}
public void setIncludes(String includes) {
super.setIncludes(includes);
this.includes = includes;
}
@Override
public void execute() {
if (includes != null && includes.trim().isEmpty())
return;
DirectoryScanner s = getDirectoryScanner(srcDir);
String[] files = s.getIncludedFiles();
// System.err.println("Ant.execute: srcDir " + srcDir);
// System.err.println("Ant.execute: destDir " + destDir);
// System.err.println("Ant.execute: files " + Arrays.asList(files));
files = filter(srcDir, destDir, files);
if (files.length == 0)
return;
System.out.println("Generating " + files.length + " stub files to " + destDir);
List<String> classNames = new ArrayList<String>();
for (String file: files) {
classNames.add(file.replaceAll(".java$", "").replace('/', '.'));
}
if (!fork) {
GenStubs m = new GenStubs();
boolean ok = m.run(srcDir.getPath(), destDir, classNames);
if (!ok)
throw new BuildException("genstubs failed");
} else {
List<String> cmd = new ArrayList<String>();
String java_home = System.getProperty("java.home");
cmd.add(new File(new File(java_home, "bin"), "java").getPath());
if (classpath != null)
cmd.add("-Xbootclasspath/p:" + classpath);
cmd.add(GenStubs.class.getName());
cmd.add("-sourcepath");
cmd.add(srcDir.getPath());
cmd.add("-s");
cmd.add(destDir.getPath());
cmd.addAll(classNames);
//System.err.println("GenStubs exec " + cmd);
ProcessBuilder pb = new ProcessBuilder(cmd);
pb.redirectErrorStream(true);
try {
Process p = pb.start();
BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));
try {
String line;
while ((line = in.readLine()) != null)
System.out.println(line);
} finally {
in.close();
}
int rc = p.waitFor();
if (rc != 0)
throw new BuildException("genstubs failed");
} catch (IOException e) {
throw new BuildException("genstubs failed", e);
} catch (InterruptedException e) {
throw new BuildException("genstubs failed", e);
}
}
}
String[] filter(File srcDir, File destDir, String[] files) {
List<String> results = new ArrayList<String>();
for (String f: files) {
long srcTime = new File(srcDir, f).lastModified();
long destTime = new File(destDir, f).lastModified();
if (srcTime > destTime)
results.add(f);
}
return results.toArray(new String[results.size()]);
}
}
}