1 /*

     2  * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 import java.io.*;

    27 import java.util.*;

    28 import javax.tools.JavaFileObject;

    29 import javax.tools.StandardJavaFileManager;

    30 import javax.tools.StandardLocation;

    31 

    32 import org.apache.tools.ant.BuildException;

    33 import org.apache.tools.ant.DirectoryScanner;

    34 import org.apache.tools.ant.taskdefs.MatchingTask;

    35 import org.apache.tools.ant.types.Path;

    36 import org.apache.tools.ant.types.Reference;

    37 

    38 

    39 import com.sun.source.tree.CompilationUnitTree;

    40 import com.sun.source.util.JavacTask;

    41 import com.sun.tools.javac.api.JavacTool;

    42 import com.sun.tools.javac.code.Flags;

    43 import com.sun.tools.javac.code.TypeTags;

    44 import com.sun.tools.javac.tree.JCTree;

    45 import com.sun.tools.javac.tree.JCTree.JCCompilationUnit;

    46 import com.sun.tools.javac.tree.JCTree.JCFieldAccess;

    47 import com.sun.tools.javac.tree.JCTree.JCIdent;

    48 import com.sun.tools.javac.tree.JCTree.JCImport;

    49 import com.sun.tools.javac.tree.JCTree.JCLiteral;

    50 import com.sun.tools.javac.tree.JCTree.JCMethodDecl;

    51 import com.sun.tools.javac.tree.JCTree.JCModifiers;

    52 import com.sun.tools.javac.tree.JCTree.JCVariableDecl;

    53 import com.sun.tools.javac.tree.Pretty;

    54 import com.sun.tools.javac.tree.TreeMaker;

    55 import com.sun.tools.javac.tree.TreeScanner;

    56 import com.sun.tools.javac.tree.TreeTranslator;

    57 import com.sun.tools.javac.util.Context;

    58 import com.sun.tools.javac.util.ListBuffer;

    59 import com.sun.tools.javac.util.Name;

    60 import javax.tools.JavaFileManager;

    61 

    62 /**

    63  * Generate stub source files by removing implementation details from input files.

    64  *

    65  * This is a special purpose stub generator, specific to the needs of generating

    66  * stub files for JDK 7 API that are needed to compile langtools files that depend

    67  * on that API. The stub generator works by removing as much of the API source code

    68  * as possible without affecting the public signature, in order to reduce the

    69  * transitive closure of the API being referenced. The resulting stubs can be

    70  * put on the langtools sourcepath with -implicit:none to compile the langtools

    71  * files that depend on the JDK 7 API.

    72  *

    73  * Usage:

    74  *  genstubs -s <outdir> -sourcepath <path> <classnames>

    75  *

    76  * The specified class names are looked up on the sourcepath, and corresponding

    77  * stubs are written to the source output directory.

    78  *

    79  * Classes are parsed into javac ASTs, then processed with a javac TreeTranslator

    80  * to remove implementation details, and written out in the source output directory.

    81  * Documentation comments and annotations are removed. Method bodies are removed

    82  * and methods are marked native. Private and package-private field definitions

    83  * have their initializers replace with 0, 0.0, false, null as appropriate.

    84  *

    85  * An Ant task, Main$Ant is also provided. Files are specified with an implicit

    86  * fileset, using srcdir as a base directory. The set of files to be included

    87  * is specified with an includes attribute or nested <includes> set. However,

    88  * unlike a normal fileset, an empty includes attribute means "no files" instead

    89  * of "all files".  The Ant task also accepts "fork=true" and classpath attribute

    90  * or nested <classpath> element to run GenStubs in a separate VM with the specified

    91  * path. This is likely necessary if a JDK 7 parser is required to read the

    92  * JDK 7 input files.

    93  */

    94 

    95 public class GenStubs {

    96     static class Fault extends Exception {

    97         private static final long serialVersionUID = 0;

    98         Fault(String message) {

    99             super(message);

   100         }

   101         Fault(String message, Throwable cause) {

   102             super(message);

   103             initCause(cause);

   104         }

   105     }

   106 

   107     public static void main(String[] args) {

   108         boolean ok = new GenStubs().run(args);

   109         if (!ok)

   110             System.exit(1);

   111     }

   112 

   113     boolean run(String... args) {

   114         File outdir = null;

   115         String sourcepath = null;

   116         List<String> classes = new ArrayList<String>();

   117         for (ListIterator<String> iter = Arrays.asList(args).listIterator(); iter.hasNext(); ) {

   118             String arg = iter.next();

   119             if (arg.equals("-s") && iter.hasNext())

   120                 outdir = new File(iter.next());

   121             else if (arg.equals("-sourcepath") && iter.hasNext())

   122                 sourcepath = iter.next();

   123             else if (arg.startsWith("-"))

   124                 throw new IllegalArgumentException(arg);

   125             else {

   126                 classes.add(arg);

   127                 while (iter.hasNext())

   128                     classes.add(iter.next());

   129             }

   130         }

   131 

   132         return run(sourcepath, outdir, classes);

   133     }

   134 

   135     boolean run(String sourcepath, File outdir, List<String> classes) {

   136         //System.err.println("run: sourcepath:" + sourcepath + " outdir:" + outdir + " classes:" + classes);

   137         if (sourcepath == null)

   138             throw new IllegalArgumentException("sourcepath not set");

   139         if (outdir == null)

   140             throw new IllegalArgumentException("source output dir not set");

   141 

   142         JavacTool tool = JavacTool.create();

   143         StandardJavaFileManager fm = tool.getStandardFileManager(null, null, null);

   144 

   145         try {

   146             fm.setLocation(StandardLocation.SOURCE_OUTPUT, Collections.singleton(outdir));

   147             fm.setLocation(StandardLocation.SOURCE_PATH, splitPath(sourcepath));

   148             List<JavaFileObject> files = new ArrayList<JavaFileObject>();

   149             for (String c: classes) {

   150                 JavaFileObject fo = fm.getJavaFileForInput(

   151                         StandardLocation.SOURCE_PATH, c, JavaFileObject.Kind.SOURCE);

   152                 if (fo == null)

   153                     error("class not found: " + c);

   154                 else

   155                     files.add(fo);

   156             }

   157 

   158             JavacTask t = tool.getTask(null, fm, null, null, null, files);

   159             Iterable<? extends CompilationUnitTree> trees = t.parse();

   160             for (CompilationUnitTree tree: trees) {

   161                 makeStub(fm, tree);

   162             }

   163         } catch (IOException e) {

   164             error("IO error " + e, e);

   165         }

   166 

   167         return (errors == 0);

   168     }

   169 

   170     void makeStub(StandardJavaFileManager fm, CompilationUnitTree tree) throws IOException {

   171         CompilationUnitTree tree2 = new StubMaker().translate(tree);

   172         CompilationUnitTree tree3 = new ImportCleaner(fm).removeRedundantImports(tree2);

   173 

   174         String className = fm.inferBinaryName(StandardLocation.SOURCE_PATH, tree.getSourceFile());

   175         JavaFileObject fo = fm.getJavaFileForOutput(StandardLocation.SOURCE_OUTPUT,

   176                 className, JavaFileObject.Kind.SOURCE, null);

   177         // System.err.println("Writing " + className + " to " + fo.getName());

   178         Writer out = fo.openWriter();

   179         try {

   180             new Pretty(out, true).printExpr((JCTree) tree3);

   181         } finally {

   182             out.close();

   183         }

   184     }

   185 

   186     List<File> splitPath(String path) {

   187         List<File> list = new ArrayList<File>();

   188         for (String p: path.split(File.pathSeparator)) {

   189             if (p.length() > 0)

   190                 list.add(new File(p));

   191         }

   192         return list;

   193     }

   194 

   195     void error(String message) {

   196         System.err.println(message);

   197         errors++;

   198     }

   199 

   200     void error(String message, Throwable cause) {

   201         error(message);

   202     }

   203 

   204     int errors;

   205 

   206     class StubMaker extends TreeTranslator {

   207         CompilationUnitTree translate(CompilationUnitTree tree) {

   208             return super.translate((JCCompilationUnit) tree);

   209         }

   210 

   211         /**

   212          * compilation units: remove javadoc comments

   213          * -- required, in order to remove @deprecated tags, since we

   214          * (separately) remove all annotations, including @Deprecated

   215          */

   216         public void visitTopLevel(JCCompilationUnit tree) {

   217             super.visitTopLevel(tree);

   218             tree.docComments = Collections.emptyMap();

   219         }

   220 

   221         /**

   222          * methods: remove method bodies, make methods native

   223          */

   224         @Override

   225         public void visitMethodDef(JCMethodDecl tree) {

   226             tree.mods = translate(tree.mods);

   227             tree.restype = translate(tree.restype);

   228             tree.typarams = translateTypeParams(tree.typarams);

   229             tree.params = translateVarDefs(tree.params);

   230             tree.thrown = translate(tree.thrown);

   231             if (tree.restype != null && tree.body != null) {

   232                 tree.mods.flags |= Flags.NATIVE;

   233                 tree.body = null;

   234             }

   235             result = tree;

   236         }

   237 

   238         /**

   239          * modifiers: remove annotations

   240          */

   241         @Override

   242         public void visitModifiers(JCModifiers tree) {

   243             tree.annotations = com.sun.tools.javac.util.List.nil();

   244             result = tree;

   245         }

   246 

   247         /**

   248          * field definitions: replace initializers with 0, 0.0, false etc

   249          * when possible -- i.e. leave public, protected initializers alone

   250          */

   251         @Override

   252         public void visitVarDef(JCVariableDecl tree) {

   253             tree.mods = translate(tree.mods);

   254             tree.vartype = translate(tree.vartype);

   255             if (tree.init != null) {

   256                 if ((tree.mods.flags & (Flags.PUBLIC | Flags.PROTECTED)) != 0)

   257                     tree.init = translate(tree.init);

   258                 else {

   259                     String t = tree.vartype.toString();

   260                     if (t.equals("boolean"))

   261                         tree.init = new JCLiteral(TypeTags.BOOLEAN, 0) { };

   262                     else if (t.equals("byte"))

   263                         tree.init = new JCLiteral(TypeTags.BYTE, 0) { };

   264                     else if (t.equals("char"))

   265                         tree.init = new JCLiteral(TypeTags.CHAR, 0) { };

   266                     else if (t.equals("double"))

   267                         tree.init = new JCLiteral(TypeTags.DOUBLE, 0.d) { };

   268                     else if (t.equals("float"))

   269                         tree.init = new JCLiteral(TypeTags.FLOAT, 0.f) { };

   270                     else if (t.equals("int"))

   271                         tree.init = new JCLiteral(TypeTags.INT, 0) { };

   272                     else if (t.equals("long"))

   273                         tree.init = new JCLiteral(TypeTags.LONG, 0) { };

   274                     else if (t.equals("short"))

   275                         tree.init = new JCLiteral(TypeTags.SHORT, 0) { };

   276                     else

   277                         tree.init = new JCLiteral(TypeTags.BOT, null) { };

   278                 }

   279             }

   280             result = tree;

   281         }

   282     }

   283 

   284     class ImportCleaner extends TreeScanner {

   285         private Set<Name> names = new HashSet<Name>();

   286         private TreeMaker m;

   287 

   288         ImportCleaner(JavaFileManager fm) {

   289             // ImportCleaner itself doesn't require a filemanager, but instantiating

   290             // a TreeMaker does, indirectly (via ClassReader, sigh)

   291             Context c = new Context();

   292             c.put(JavaFileManager.class, fm);

   293             m = TreeMaker.instance(c);

   294         }

   295 

   296         CompilationUnitTree removeRedundantImports(CompilationUnitTree t) {

   297             JCCompilationUnit tree = (JCCompilationUnit) t;

   298             tree.accept(this);

   299             ListBuffer<JCTree> defs = new ListBuffer<JCTree>();

   300             for (JCTree def: tree.defs) {

   301                 if (def.getTag() == JCTree.IMPORT) {

   302                     JCImport imp = (JCImport) def;

   303                     if (imp.qualid.getTag() == JCTree.SELECT) {

   304                         JCFieldAccess qualid = (JCFieldAccess) imp.qualid;

   305                         if (!qualid.name.toString().equals("*")

   306                                 && !names.contains(qualid.name)) {

   307                             continue;

   308                         }

   309                     }

   310                 }

   311                 defs.add(def);

   312             }

   313             return m.TopLevel(tree.packageAnnotations, tree.pid, defs.toList());

   314         }

   315 

   316         @Override

   317         public void visitImport(JCImport tree) { } // ignore names found in imports

   318 

   319         @Override

   320         public void visitIdent(JCIdent tree) {

   321             names.add(tree.name);

   322         }

   323 

   324         @Override

   325         public void visitSelect(JCFieldAccess tree) {

   326             super.visitSelect(tree);

   327             names.add(tree.name);

   328         }

   329     }

   330 

   331     //---------- Ant Invocation ------------------------------------------------

   332 

   333     public static class Ant extends MatchingTask {

   334         private File srcDir;

   335         private File destDir;

   336         private boolean fork;

   337         private Path classpath;

   338         private String includes;

   339 

   340         public void setSrcDir(File dir) {

   341             this.srcDir = dir;

   342         }

   343 

   344         public void setDestDir(File dir) {

   345             this.destDir = dir;

   346         }

   347 

   348         public void setFork(boolean v) {

   349             this.fork = v;

   350         }

   351 

   352         public void setClasspath(Path cp) {

   353             if (classpath == null)

   354                 classpath = cp;

   355             else

   356                 classpath.append(cp);

   357         }

   358 

   359         public Path createClasspath() {

   360             if (classpath == null) {

   361                 classpath = new Path(getProject());

   362             }

   363             return classpath.createPath();

   364         }

   365 

   366         public void setClasspathRef(Reference r) {

   367             createClasspath().setRefid(r);

   368         }

   369 

   370         public void setIncludes(String includes) {

   371             super.setIncludes(includes);

   372             this.includes = includes;

   373         }

   374 

   375         @Override

   376         public void execute() {

   377             if (includes != null && includes.trim().isEmpty())

   378                 return;

   379 

   380             DirectoryScanner s = getDirectoryScanner(srcDir);

   381             String[] files = s.getIncludedFiles();

   382 //            System.err.println("Ant.execute: srcDir " + srcDir);

   383 //            System.err.println("Ant.execute: destDir " + destDir);

   384 //            System.err.println("Ant.execute: files " + Arrays.asList(files));

   385 

   386             files = filter(srcDir, destDir, files);

   387             if (files.length == 0)

   388                 return;

   389             System.out.println("Generating " + files.length + " stub files to " + destDir);

   390 

   391             List<String> classNames = new ArrayList<String>();

   392             for (String file: files) {

   393                 classNames.add(file.replaceAll(".java$", "").replace('/', '.'));

   394             }

   395 

   396             if (!fork) {

   397                 GenStubs m = new GenStubs();

   398                 boolean ok = m.run(srcDir.getPath(), destDir, classNames);

   399                 if (!ok)

   400                     throw new BuildException("genstubs failed");

   401             } else {

   402                 List<String> cmd = new ArrayList<String>();

   403                 String java_home = System.getProperty("java.home");

   404                 cmd.add(new File(new File(java_home, "bin"), "java").getPath());

   405                 if (classpath != null)

   406                     cmd.add("-Xbootclasspath/p:" + classpath);

   407                 cmd.add(GenStubs.class.getName());

   408                 cmd.add("-sourcepath");

   409                 cmd.add(srcDir.getPath());

   410                 cmd.add("-s");

   411                 cmd.add(destDir.getPath());

   412                 cmd.addAll(classNames);

   413                 //System.err.println("GenStubs exec " + cmd);

   414                 ProcessBuilder pb = new ProcessBuilder(cmd);

   415                 pb.redirectErrorStream(true);

   416                 try {

   417                     Process p = pb.start();

   418                     BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));

   419                     try {

   420                         String line;

   421                         while ((line = in.readLine()) != null)

   422                             System.out.println(line);

   423                     } finally {

   424                         in.close();

   425                     }

   426                     int rc = p.waitFor();

   427                     if (rc != 0)

   428                         throw new BuildException("genstubs failed");

   429                 } catch (IOException e) {

   430                     throw new BuildException("genstubs failed", e);

   431                 } catch (InterruptedException e) {

   432                     throw new BuildException("genstubs failed", e);

   433                 }

   434             }

   435         }

   436 

   437         String[] filter(File srcDir, File destDir, String[] files) {

   438             List<String> results = new ArrayList<String>();

   439             for (String f: files) {

   440                 long srcTime = new File(srcDir, f).lastModified();

   441                 long destTime = new File(destDir, f).lastModified();

   442                 if (srcTime > destTime)

   443                     results.add(f);

   444             }

   445             return results.toArray(new String[results.size()]);

   446         }

   447     }

   448 }