| /* VMClassLoader.java -- Reference implementation of compiler interface |
| Copyright (C) 2004, 2005, 2006 Free Software Foundation |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| package java.lang; |
| |
| import java.io.File; |
| import java.io.FileOutputStream; |
| import java.io.InputStreamReader; |
| import java.security.MessageDigest; |
| import java.security.ProtectionDomain; |
| import java.security.NoSuchAlgorithmException; |
| import java.util.WeakHashMap; |
| import java.util.HashSet; |
| import java.util.Enumeration; |
| import java.util.StringTokenizer; |
| import java.util.Vector; |
| import gnu.gcj.runtime.SharedLibHelper; |
| import gnu.gcj.runtime.PersistentByteMap; |
| import gnu.java.security.hash.MD5; |
| |
| /** |
| * This class is just a per-VM reflection of java.lang.Compiler. |
| * All methods are defined identically. |
| */ |
| final class VMCompiler |
| { |
| // True if we want to use gcj-jit. |
| public static boolean useCompiler = true; |
| |
| // True if we're able to use gcj-jit. |
| public static final boolean canUseCompiler; |
| |
| // Compiler to use. |
| public static String gcjJitCompiler; |
| |
| // Compiler options. |
| public static String gcjJitCompilerOptions; |
| |
| // Temporary directory to use. |
| public static String gcjJitTmpdir; |
| |
| // This maps a ClassLoader to a set of SharedLibHelper objects that |
| // it has used. We do things this way to ensure that a |
| // SharedLibHelper is collected if and only if the ClassLoader is. |
| private static WeakHashMap sharedHelperMap = new WeakHashMap(); |
| |
| private static Vector precompiledMapFiles; |
| |
| // We create a single MD5 engine and then clone it whenever we want |
| // a new one. |
| |
| // We don't use |
| // |
| // md5Digest = MessageDigest.getInstance("MD5"); |
| // |
| // here because that loads a great deal of security provider code as |
| // interpreted bytecode -- before we're able to use this class to |
| // load precompiled classes. |
| |
| private static final MD5 md5Digest |
| = new gnu.java.security.hash.MD5(); |
| |
| static |
| { |
| gcjJitCompiler = System.getProperty("gnu.gcj.jit.compiler"); |
| if (gcjJitCompiler == null) |
| canUseCompiler = false; |
| else |
| { |
| gcjJitCompilerOptions = System.getProperty("gnu.gcj.jit.options", |
| "-g"); |
| gcjJitTmpdir = System.getProperty("gnu.gcj.jit.cachedir"); |
| // Note that we *don't* choose java.io.tmpdir as a default -- |
| // that would allow easy attacks against the VM. |
| if (gcjJitTmpdir == null) |
| canUseCompiler = false; |
| else |
| canUseCompiler = true; |
| } |
| |
| String prop = System.getProperty ("gnu.gcj.precompiled.db.path"); |
| if (prop != null) |
| { |
| precompiledMapFiles = new Vector(); |
| // Add the |
| StringTokenizer st |
| = new StringTokenizer (prop, |
| System.getProperty ("path.separator", ":")); |
| { |
| while (st.hasMoreElements ()) |
| { |
| String e = st.nextToken (); |
| try |
| { |
| PersistentByteMap map |
| = new PersistentByteMap |
| (e, PersistentByteMap.AccessMode.READ_ONLY); |
| precompiledMapFiles.add(map); |
| } |
| catch (IllegalArgumentException _) |
| { |
| // Not a map file |
| } |
| catch (java.io.IOException _) |
| { |
| } |
| catch (java.nio.BufferUnderflowException _) |
| { |
| // Invalid map file. |
| } |
| } |
| } |
| } |
| } |
| |
| /** |
| * Don't allow new `Compiler's to be made. |
| */ |
| private VMCompiler() |
| { |
| } |
| |
| private static Class loadSharedLibrary(ClassLoader loader, |
| String fileName, |
| ProtectionDomain domain, |
| String className) |
| { |
| Class c = null; |
| SharedLibHelper helper |
| = SharedLibHelper.findHelper (loader, fileName, domain.getCodeSource(), |
| domain, false); |
| c = helper.findClass (className); |
| if (c != null) |
| { |
| HashSet hs = (HashSet) sharedHelperMap.get(loader); |
| if (hs == null) |
| { |
| hs = new HashSet(); |
| sharedHelperMap.put(loader, hs); |
| } |
| hs.add(helper); |
| } |
| return c; |
| } |
| |
| /** |
| * Compile a class given the bytes for it. Returns the Class, or |
| * null if compilation failed or otherwise could not be done. |
| */ |
| public static Class compileClass(ClassLoader loader, |
| String name, byte[] data, |
| int offset, int len, |
| ProtectionDomain domain) |
| { |
| if (precompiledMapFiles == null |
| && (! useCompiler || ! canUseCompiler)) |
| return null; |
| |
| byte digest[]; |
| |
| try |
| { |
| MD5 md = (MD5) md5Digest.clone(); |
| md.update(data); |
| digest = md.digest(); |
| } |
| catch (NullPointerException _) |
| { |
| // If md5Digest==null -- but really this should never happen |
| // either, since the MD5 digest is in libgcj. |
| return null; |
| } |
| |
| // We use lookaside cache files to determine whether these bytes |
| // correspond to a class file that is part of a precompiled DSO. |
| if (precompiledMapFiles != null) |
| { |
| try |
| { |
| Enumeration elements = precompiledMapFiles.elements(); |
| while (elements.hasMoreElements()) |
| { |
| PersistentByteMap map = (PersistentByteMap)elements.nextElement(); |
| byte[] soName = map.get(digest); |
| if (soName != null) |
| return loadSharedLibrary(loader, |
| new String(soName), |
| domain, name); |
| } |
| } |
| catch (Exception _) |
| { |
| } |
| catch (UnknownError _) |
| { |
| // SharedLibHelper will throw UnknownError if the dlopen |
| // fails for some reason. We ignore it and continue on. |
| } |
| } |
| |
| if (! useCompiler || ! canUseCompiler) |
| return null; |
| |
| try |
| { |
| // FIXME: Make sure that the class represented by the |
| // bytes in DATA really is the class named in NAME. Make |
| // sure it's not "java.*". |
| StringBuffer hexBytes = new StringBuffer(gcjJitTmpdir); |
| hexBytes.append(File.separatorChar); |
| int digestLength = digest.length; |
| for (int i = 0; i < digestLength; ++i) |
| hexBytes.append(Integer.toHexString(digest[i] & 0xff)); |
| |
| // FIXME: use System.mapLibraryName? |
| // I'm thinking we should use that, plus a class specified |
| // via a property that determines lookup policy. |
| File soFile = new File(hexBytes + ".so"); |
| if (soFile.isFile()) |
| return loadSharedLibrary (loader, soFile.toString(), domain, |
| name); |
| |
| File classFile = new File(hexBytes + ".class"); |
| classFile.delete(); |
| if (classFile.createNewFile() != true) |
| return null; |
| |
| FileOutputStream f = new FileOutputStream (classFile); |
| // FIXME: race condition if bytes change... ? |
| f.write(data, offset, len); |
| |
| // Invoke the compiler. |
| StringBuffer command = new StringBuffer(gcjJitCompiler); |
| command.append(" "); |
| command.append(classFile); |
| command.append(" "); |
| command.append(gcjJitCompilerOptions); |
| // These options are required. |
| command.append(" -findirect-dispatch -fjni -shared -fPIC -o "); |
| command.append(soFile); |
| Process p = Runtime.getRuntime().exec(command.toString()); |
| |
| // Read the process' stderr into a string. |
| StringBuffer err = new StringBuffer(); |
| InputStreamReader stderr = new InputStreamReader (p.getErrorStream()); |
| char[] inBuf = new char[500]; |
| int bytesRead; |
| while ((bytesRead = stderr.read (inBuf)) != -1) |
| err.append(inBuf, 0, bytesRead); |
| |
| if (p.waitFor() != 0) |
| { |
| // FIXME: we could log err.toString() somewhere... |
| return null; |
| } |
| |
| return loadSharedLibrary(loader, soFile.toString(), domain, name); |
| } |
| catch (Exception _) |
| { |
| return null; |
| } |
| } |
| |
| /** |
| * Compile the class named by <code>oneClass</code>. |
| * |
| * @param oneClass the class to compile |
| * @return <code>false</code> if no compiler is available or |
| * compilation failed, <code>true</code> if compilation succeeded |
| * @throws NullPointerException if oneClass is null |
| */ |
| public static boolean compileClass(Class oneClass) |
| { |
| // Never succeed. |
| return false; |
| } |
| |
| /** |
| * Compile the classes whose name matches <code>classNames</code>. |
| * |
| * @param classNames the name of classes to compile |
| * @return <code>false</code> if no compiler is available or |
| * compilation failed, <code>true</code> if compilation succeeded |
| * @throws NullPointerException if classNames is null |
| */ |
| public static boolean compileClasses(String classNames) |
| { |
| // Note the incredibly lame interface. Always fail. |
| return false; |
| } |
| |
| /** |
| * This method examines the argument and performs an operation |
| * according to the compilers documentation. No specific operation |
| * is required. |
| * |
| * @param arg a compiler-specific argument |
| * @return a compiler-specific value, including null |
| * @throws NullPointerException if the compiler doesn't like a null arg |
| */ |
| public static Object command(Object arg) |
| { |
| // Our implementation defines this to a no-op. |
| return null; |
| } |
| |
| /** |
| * Calling <code>Compiler.enable()</code> will cause the compiler |
| * to resume operation if it was previously disabled; provided that a |
| * compiler even exists. |
| */ |
| public static void enable() |
| { |
| useCompiler = true; |
| } |
| |
| /** |
| * Calling <code>Compiler.disable()</code> will cause the compiler |
| * to be suspended; provided that a compiler even exists. |
| */ |
| public static void disable() |
| { |
| useCompiler = false; |
| } |
| } |