src/java_tools/buildjar/java/com/google/devtools/build/buildjar/genclass/GenClass.java - bazel - Git at Google

 // Copyright 2015 The Bazel Authors. All rights reserved.
 //
 // 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 com.google.devtools.build.buildjar.genclass;

 import static com.google.common.collect.ImmutableSet.toImmutableSet;

 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ImmutableSet;
 import com.google.devtools.build.buildjar.jarhelper.JarCreator;
 import com.google.devtools.build.buildjar.proto.JavaCompilation.CompilationUnit;
 import com.google.devtools.build.buildjar.proto.JavaCompilation.Manifest;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.file.FileVisitResult;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.SimpleFileVisitor;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.Arrays;
 import java.util.Enumeration;
 import java.util.List;
 import java.util.function.Predicate;
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
 import java.util.stream.Stream;

 /**
  * GenClass post-processes the output of a Java compilation, and produces a jar containing only the
  * class files for sources that were generated by annotation processors.
  */
 public class GenClass {

   /** Recursively delete a directory. */
   private static void deleteTree(Path directory) throws IOException {
     if (directory.toFile().exists()) {
       Files.walkFileTree(
           directory,
           new SimpleFileVisitor<Path>() {
             @Override
             public FileVisitResult visitFile(Path file, BasicFileAttributes attrs)
                 throws IOException {
               Files.delete(file);
               return FileVisitResult.CONTINUE;
             }

             @Override
             public FileVisitResult postVisitDirectory(Path dir, IOException exc)
                 throws IOException {
               Files.delete(dir);
               return FileVisitResult.CONTINUE;
             }
           });
     }
   }

   public static void main(String[] args) throws IOException {
     GenClassOptions options = GenClassOptionsParser.parse(Arrays.asList(args));
     Manifest manifest = readManifest(options.manifest());

     if (!options.getGeneratedSourceJars().isEmpty()) {
       Manifest generatedJarsManifest = readGeneratedSourceJars(options.getGeneratedSourceJars());
       manifest = Manifest.newBuilder(manifest).mergeFrom(generatedJarsManifest).build();
     }

     deleteTree(options.tempDir());
     Files.createDirectories(options.tempDir());
     extractGeneratedClasses(options.classJar(), manifest, options.tempDir());
     writeOutputJar(options);
   }

   /** Reads the compilation manifest. */
   private static Manifest readManifest(Path path) throws IOException {
     Manifest manifest;
     try (InputStream inputStream = Files.newInputStream(path)) {
       manifest = Manifest.parseFrom(inputStream);
     }
     return manifest;
   }

   /** Reads the list of source jars and generates a Manifest based on the jars' entries. */
   @VisibleForTesting
   static Manifest readGeneratedSourceJars(List<Path> generatedSourceJarPaths) throws IOException {

     Manifest.Builder manifestBuilder = Manifest.newBuilder();
     for (Path generatedSourceJarPath : generatedSourceJarPaths) {

       try (JarFile jar = new JarFile(generatedSourceJarPath.toFile())) {

         Enumeration<JarEntry> entries = jar.entries();
         while (entries.hasMoreElements()) {

           JarEntry entry = entries.nextElement();
           String path = entry.getName();
           if (!path.endsWith(".java")) {
             continue;
           }

           // This assumes that there is only 1 compilation unit in the Java file, and that the Java
           // file's package matches its path in the jar.

           int lastSlash = path.lastIndexOf("/");
           String className = path.substring(lastSlash + 1, path.length() - ".java".length());
           String pkg;
           if (lastSlash == -1) {
             pkg = "";
           } else {
             pkg = path.substring(0, lastSlash).replace('/', '.');
           }
           manifestBuilder.addCompilationUnit(
               CompilationUnit.newBuilder()
                   .setPath(path)
                   .setPkg(pkg)
                   .setGeneratedByAnnotationProcessor(true)
                   .addTopLevel(className)
                   .build());
         }
       }
     }

     return manifestBuilder.build();
   }

   /**
    * For each top-level class in the compilation matching the given predicate, determine the path
    * prefix of classes corresponding to that compilation unit.
    */
   @VisibleForTesting
   static ImmutableSet<String> getPrefixes(Manifest manifest, Predicate<CompilationUnit> p) {
     return manifest
         .getCompilationUnitList()
         .stream()
         .filter(p)
         .flatMap(unit -> getUnitPrefixes(unit))
         .collect(toImmutableSet());
   }

   /**
    * Prefixes are used to correctly handle inner classes, e.g. the top-level class "c.g.Foo" may
    * correspond to "c/g/Foo.class" and also "c/g/Foo$Inner.class" or "c/g/Foo$0.class".
    */
   private static Stream<String> getUnitPrefixes(CompilationUnit unit) {
     String pkg;
     if (unit.hasPkg()) {
       pkg = unit.getPkg().replace('.', '/') + "/";
     } else {
       pkg = "";
     }
     return unit.getTopLevelList().stream().map(toplevel -> pkg + toplevel);
   }

   /**
    * Unzip all the class files that correspond to annotation processor- generated sources into the
    * temporary directory.
    */
   private static void extractGeneratedClasses(Path classJar, Manifest manifest, Path tempDir)
       throws IOException {
     ImmutableSet<String> generatedFilePrefixes =
         getPrefixes(manifest, unit -> unit.getGeneratedByAnnotationProcessor());
     ImmutableSet<String> userWrittenFilePrefixes =
         getPrefixes(manifest, unit -> !unit.getGeneratedByAnnotationProcessor());
     try (JarFile jar = new JarFile(classJar.toFile())) {
       Enumeration<JarEntry> entries = jar.entries();
       while (entries.hasMoreElements()) {
         JarEntry entry = entries.nextElement();
         String name = entry.getName();
         if (!name.endsWith(".class")) {
           continue;
         }
         String className = name.substring(0, name.length() - ".class".length());
         if (prefixesContains(generatedFilePrefixes, className)
             // Assume that prefixes that don't correspond to a known hand-written source are
             // generated.
             || !prefixesContains(userWrittenFilePrefixes, className)) {
           Files.createDirectories(tempDir.resolve(name).getParent());
           // InputStream closing: JarFile extends ZipFile, and ZipFile.close() will close all of the
           // input streams previously returned by invocations of the getInputStream method.
           // See https://docs.oracle.com/javase/8/docs/api/java/util/zip/ZipFile.html#close--
           Files.copy(jar.getInputStream(entry), tempDir.resolve(name));
         }
       }
     }
   }

   /**
    * We want to include inner classes for generated source files, but a class whose name contains
    * '$' isn't necessarily an inner class. Check whether any prefix of the class name that ends with
    * '$' matches one of the top-level class names.
    */
   private static boolean prefixesContains(ImmutableSet<String> prefixes, String className) {
     if (prefixes.contains(className)) {
       return true;
     }
     for (int i = className.indexOf('$'); i != -1; i = className.indexOf('$', i + 1)) {
       if (prefixes.contains(className.substring(0, i))) {
         return true;
       }
     }
     return false;
   }

   /** Writes the generated class files to the output jar. */
   private static void writeOutputJar(GenClassOptions options) throws IOException {
     JarCreator output = new JarCreator(options.outputJar().toString());
     output.setCompression(true);
     output.setNormalize(true);
     output.addDirectory(options.tempDir().toString());
     output.execute();
   }
 }
	// Copyright 2015 The Bazel Authors. All rights reserved.
	//
	// 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 com.google.devtools.build.buildjar.genclass;

	import static com.google.common.collect.ImmutableSet.toImmutableSet;

	import com.google.common.annotations.VisibleForTesting;
	import com.google.common.collect.ImmutableSet;
	import com.google.devtools.build.buildjar.jarhelper.JarCreator;
	import com.google.devtools.build.buildjar.proto.JavaCompilation.CompilationUnit;
	import com.google.devtools.build.buildjar.proto.JavaCompilation.Manifest;
	import java.io.IOException;
	import java.io.InputStream;
	import java.nio.file.FileVisitResult;
	import java.nio.file.Files;
	import java.nio.file.Path;
	import java.nio.file.SimpleFileVisitor;
	import java.nio.file.attribute.BasicFileAttributes;
	import java.util.Arrays;
	import java.util.Enumeration;
	import java.util.List;
	import java.util.function.Predicate;
	import java.util.jar.JarEntry;
	import java.util.jar.JarFile;
	import java.util.stream.Stream;

	/**
	* GenClass post-processes the output of a Java compilation, and produces a jar containing only the
	* class files for sources that were generated by annotation processors.
	*/
	public class GenClass {

	/** Recursively delete a directory. */
	private static void deleteTree(Path directory) throws IOException {
	if (directory.toFile().exists()) {
	Files.walkFileTree(
	directory,
	new SimpleFileVisitor<Path>() {
	@Override
	public FileVisitResult visitFile(Path file, BasicFileAttributes attrs)
	throws IOException {
	Files.delete(file);
	return FileVisitResult.CONTINUE;
	}

	@Override
	public FileVisitResult postVisitDirectory(Path dir, IOException exc)
	throws IOException {
	Files.delete(dir);
	return FileVisitResult.CONTINUE;
	}
	});
	}
	}

	public static void main(String[] args) throws IOException {
	GenClassOptions options = GenClassOptionsParser.parse(Arrays.asList(args));
	Manifest manifest = readManifest(options.manifest());

	if (!options.getGeneratedSourceJars().isEmpty()) {
	Manifest generatedJarsManifest = readGeneratedSourceJars(options.getGeneratedSourceJars());
	manifest = Manifest.newBuilder(manifest).mergeFrom(generatedJarsManifest).build();
	}

	deleteTree(options.tempDir());
	Files.createDirectories(options.tempDir());
	extractGeneratedClasses(options.classJar(), manifest, options.tempDir());
	writeOutputJar(options);
	}

	/** Reads the compilation manifest. */
	private static Manifest readManifest(Path path) throws IOException {
	Manifest manifest;
	try (InputStream inputStream = Files.newInputStream(path)) {
	manifest = Manifest.parseFrom(inputStream);
	}
	return manifest;
	}

	/** Reads the list of source jars and generates a Manifest based on the jars' entries. */
	@VisibleForTesting
	static Manifest readGeneratedSourceJars(List<Path> generatedSourceJarPaths) throws IOException {

	Manifest.Builder manifestBuilder = Manifest.newBuilder();
	for (Path generatedSourceJarPath : generatedSourceJarPaths) {

	try (JarFile jar = new JarFile(generatedSourceJarPath.toFile())) {

	Enumeration<JarEntry> entries = jar.entries();
	while (entries.hasMoreElements()) {

	JarEntry entry = entries.nextElement();
	String path = entry.getName();
	if (!path.endsWith(".java")) {
	continue;
	}

	// This assumes that there is only 1 compilation unit in the Java file, and that the Java
	// file's package matches its path in the jar.

	int lastSlash = path.lastIndexOf("/");
	String className = path.substring(lastSlash + 1, path.length() - ".java".length());
	String pkg;
	if (lastSlash == -1) {
	pkg = "";
	} else {
	pkg = path.substring(0, lastSlash).replace('/', '.');
	}
	manifestBuilder.addCompilationUnit(
	CompilationUnit.newBuilder()
	.setPath(path)
	.setPkg(pkg)
	.setGeneratedByAnnotationProcessor(true)
	.addTopLevel(className)
	.build());
	}
	}
	}

	return manifestBuilder.build();
	}

	/**
	* For each top-level class in the compilation matching the given predicate, determine the path
	* prefix of classes corresponding to that compilation unit.
	*/
	@VisibleForTesting
	static ImmutableSet<String> getPrefixes(Manifest manifest, Predicate<CompilationUnit> p) {
	return manifest
	.getCompilationUnitList()
	.stream()
	.filter(p)
	.flatMap(unit -> getUnitPrefixes(unit))
	.collect(toImmutableSet());
	}

	/**
	* Prefixes are used to correctly handle inner classes, e.g. the top-level class "c.g.Foo" may
	* correspond to "c/g/Foo.class" and also "c/g/Foo$Inner.class" or "c/g/Foo$0.class".
	*/
	private static Stream<String> getUnitPrefixes(CompilationUnit unit) {
	String pkg;
	if (unit.hasPkg()) {
	pkg = unit.getPkg().replace('.', '/') + "/";
	} else {
	pkg = "";
	}
	return unit.getTopLevelList().stream().map(toplevel -> pkg + toplevel);
	}

	/**
	* Unzip all the class files that correspond to annotation processor- generated sources into the
	* temporary directory.
	*/
	private static void extractGeneratedClasses(Path classJar, Manifest manifest, Path tempDir)
	throws IOException {
	ImmutableSet<String> generatedFilePrefixes =
	getPrefixes(manifest, unit -> unit.getGeneratedByAnnotationProcessor());
	ImmutableSet<String> userWrittenFilePrefixes =
	getPrefixes(manifest, unit -> !unit.getGeneratedByAnnotationProcessor());
	try (JarFile jar = new JarFile(classJar.toFile())) {
	Enumeration<JarEntry> entries = jar.entries();
	while (entries.hasMoreElements()) {
	JarEntry entry = entries.nextElement();
	String name = entry.getName();
	if (!name.endsWith(".class")) {
	continue;
	}
	String className = name.substring(0, name.length() - ".class".length());
	if (prefixesContains(generatedFilePrefixes, className)
	// Assume that prefixes that don't correspond to a known hand-written source are
	// generated.
	\|\| !prefixesContains(userWrittenFilePrefixes, className)) {
	Files.createDirectories(tempDir.resolve(name).getParent());
	// InputStream closing: JarFile extends ZipFile, and ZipFile.close() will close all of the
	// input streams previously returned by invocations of the getInputStream method.
	// See https://docs.oracle.com/javase/8/docs/api/java/util/zip/ZipFile.html#close--
	Files.copy(jar.getInputStream(entry), tempDir.resolve(name));
	}
	}
	}
	}

	/**
	* We want to include inner classes for generated source files, but a class whose name contains
	* '$' isn't necessarily an inner class. Check whether any prefix of the class name that ends with
	* '$' matches one of the top-level class names.
	*/
	private static boolean prefixesContains(ImmutableSet<String> prefixes, String className) {
	if (prefixes.contains(className)) {
	return true;
	}
	for (int i = className.indexOf('$'); i != -1; i = className.indexOf('$', i + 1)) {
	if (prefixes.contains(className.substring(0, i))) {
	return true;
	}
	}
	return false;
	}

	/** Writes the generated class files to the output jar. */
	private static void writeOutputJar(GenClassOptions options) throws IOException {
	JarCreator output = new JarCreator(options.outputJar().toString());
	output.setCompression(true);
	output.setNormalize(true);
	output.addDirectory(options.tempDir().toString());
	output.execute();
	}
	}