/*
* Copyright (c) 2015, 2016, 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
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package jdk.nashorn.tools.jjs;
import java.lang.reflect.Modifier;
import java.io.IOException;
import java.io.File;
import java.net.URI;
import java.nio.file.DirectoryStream;
import java.nio.file.Files;
import java.nio.file.FileSystem;
import java.nio.file.FileSystems;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Collections;
import java.util.EnumSet;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import javax.tools.JavaCompiler;
import javax.tools.JavaFileManager.Location;
import javax.tools.JavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.StandardLocation;
import javax.tools.ToolProvider;
import jdk.nashorn.internal.runtime.Context;
/**
* A helper class to compute properties of a Java package object. Properties of
* package object are (simple) top level class names in that java package and
* immediate subpackages of that package.
*/
final class PackagesHelper {
// JavaCompiler may be null on certain platforms (eg. JRE)
private static final JavaCompiler compiler;
static {
// Use javac only if security manager is not around!
compiler = System.getSecurityManager() == null? ToolProvider.getSystemJavaCompiler() : null;
}
/**
* Is javac available?
*
* @return true if javac is available
*/
private static boolean isJavacAvailable() {
return compiler != null;
}
private final Context context;
private final boolean modulePathSet;
private final StandardJavaFileManager fm;
private final Set<JavaFileObject.Kind> fileKinds;
private final FileSystem jrtfs;
/**
* Construct a new PackagesHelper.
*
* @param context the current Nashorn Context
*/
PackagesHelper(final Context context) throws IOException {
this.context = context;
final String modulePath = context.getEnv()._module_path;
this.modulePathSet = modulePath != null && !modulePath.isEmpty();
if (isJavacAvailable()) {
final String classPath = context.getEnv()._classpath;
fm = compiler.getStandardFileManager(null, null, null);
fileKinds = EnumSet.of(JavaFileObject.Kind.CLASS);
if (this.modulePathSet) {
fm.setLocation(StandardLocation.MODULE_PATH, getFiles(modulePath));
}
if (classPath != null && !classPath.isEmpty()) {
fm.setLocation(StandardLocation.CLASS_PATH, getFiles(classPath));
} else {
// no classpath set. Make sure that it is empty and not any default like "."
fm.setLocation(StandardLocation.CLASS_PATH, Collections.<File>emptyList());
}
jrtfs = null;
} else {
// javac is not available - directly use jrt fs
// to support at least platform classes.
fm = null;
fileKinds = null;
jrtfs = FileSystems.getFileSystem(URI.create("jrt:/"));
}
}
// LRU cache for java package properties lists
private final LinkedHashMap<String, List<String>> propsCache =
new LinkedHashMap<String, List<String>>(32, 0.75f, true) {
private static final int CACHE_SIZE = 100;
private static final long serialVersionUID = 1;
@Override
protected boolean removeEldestEntry(final Map.Entry<String, List<String>> eldest) {
return size() > CACHE_SIZE;
}
};
/**
* Return the list of properties of the given Java package or package prefix
*
* @param pkg Java package name or package prefix name
* @return the list of properties of the given Java package or package prefix
*/
List<String> getPackageProperties(final String pkg) {
// check the cache first
if (propsCache.containsKey(pkg)) {
return propsCache.get(pkg);
}
try {
// make sorted list of properties
final List<String> props = new ArrayList<>(listPackage(pkg));
Collections.sort(props);
propsCache.put(pkg, props);
return props;
} catch (final IOException exp) {
if (Main.DEBUG) {
exp.printStackTrace();
}
return Collections.<String>emptyList();
}
}
public void close() throws IOException {
if (fm != null) {
fm.close();
}
}
private Set<String> listPackage(final String pkg) throws IOException {
final Set<String> props = new HashSet<>();
if (fm != null) {
listPackage(StandardLocation.PLATFORM_CLASS_PATH, pkg, props);
if (this.modulePathSet) {
for (Set<Location> locs : fm.listLocationsForModules(StandardLocation.MODULE_PATH)) {
for (Location loc : locs) {
listPackage(loc, pkg, props);
}
}
}
listPackage(StandardLocation.CLASS_PATH, pkg, props);
} else if (jrtfs != null) {
// look for the /packages/<package_name> directory
Path pkgDir = jrtfs.getPath("/packages/" + pkg);
if (Files.exists(pkgDir)) {
String pkgSlashName = pkg.replace('.', '/');
try (DirectoryStream<Path> ds = Files.newDirectoryStream(pkgDir)) {
// it has module links under which this package occurs
for (Path mod : ds) {
// get the package directory under /modules
Path pkgUnderMod = jrtfs.getPath(mod.toString() + "/" + pkgSlashName);
try (DirectoryStream<Path> ds2 = Files.newDirectoryStream(pkgUnderMod)) {
for (Path p : ds2) {
String str = p.getFileName().toString();
// get rid of ".class", if any
if (str.endsWith(".class")) {
final String clsName = str.substring(0, str.length() - ".class".length());
if (clsName.indexOf('$') == -1 && isClassAccessible(pkg + "." + clsName)) {
props.add(str);
}
} else if (isPackageAccessible(pkg + "." + str)) {
props.add(str);
}
}
}
}
}
}
}
return props;
}
private void listPackage(final Location loc, final String pkg, final Set<String> props)
throws IOException {
for (JavaFileObject file : fm.list(loc, pkg, fileKinds, true)) {
final String binaryName = fm.inferBinaryName(loc, file);
// does not start with the given package prefix
if (!binaryName.startsWith(pkg + ".")) {
continue;
}
final int nextDot = binaryName.indexOf('.', pkg.length() + 1);
final int start = pkg.length() + 1;
if (nextDot != -1) {
// subpackage - eg. "regex" for "java.util"
final String pkgName = binaryName.substring(start, nextDot);
if (isPackageAccessible(binaryName.substring(0, nextDot))) {
props.add(binaryName.substring(start, nextDot));
}
} else {
// class - filter out nested, inner, anonymous, local classes.
// Dynalink supported public nested classes as properties of
// StaticClass object anyway. We don't want to expose those
// "$" internal names as properties of package object.
final String clsName = binaryName.substring(start);
if (clsName.indexOf('$') == -1 && isClassAccessible(binaryName)) {
props.add(clsName);
}
}
}
}
// return list of File objects for the given class path
private static List<File> getFiles(final String classPath) {
return Stream.of(classPath.split(File.pathSeparator))
.map(File::new)
.collect(Collectors.toList());
}
private boolean isClassAccessible(final String className) {
try {
final Class<?> clz = context.findClass(className);
return Modifier.isPublic(clz.getModifiers());
} catch (final ClassNotFoundException cnfe) {
}
return false;
}
private boolean isPackageAccessible(final String pkgName) {
try {
Context.checkPackageAccess(pkgName);
return true;
} catch (final SecurityException se) {
return false;
}
}
}