* Merged gcj-abi-2-dev-branch to trunk.

(Actual changes too large to list in the commit message;
see ChangeLog.)


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@91270 138bc75d-0d04-0410-961f-82ee72b054a4

5 files changed, 852 insertions, 18 deletions

diff --git a/libjava/gnu/gcj/runtime/PersistentByteMap.java b/libjava/gnu/gcj/runtime/PersistentByteMap.java
new file mode 100644
index 00000000000..90b7d33a8f4
--- /dev/null
+++ b/libjava/gnu/gcj/runtime/PersistentByteMap.java
@@ -0,0 +1,484 @@
+/* Copyright (C) 2004  Free Software Foundation
+
+   This file is part of libgcj.
+
+This software is copyrighted work licensed under the terms of the
+Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
+details.  */
+
+
+
+/*  A PersistentByteMap maps a byte array to another byte array.  It
+uses a file that does not need to be serialized but may be
+memory-mapped and read in-place.  So, even if there are many instances
+of gcj applications running, the can share PersistentByteMaps.
+
+The idea is to make searches as fast as possible: opening a
+PersistentByteMap is cheap and search time doesn't grow with the
+number of entries in the table.  On the other hand, enumerating the
+map is slow, but that is a relatively uncommon operation.
+
+The main use of this class is to provide a way to map the
+MessageDigest of a class file to the location of a DSO that contains
+the compiled version of that class.  It is up the the installer of an
+application to keep the DSO up to date with the jar.  
+
+USAGE:
+        MessageDigest md = MessageDigest.getInstance("MD5");
+        digest = md.digest(bytes);
+
+        PersistentByteMap map 
+          = new PersistentByteMap
+            (fileName, PersistentByteMap.AccessMode.READ_ONLY);
+
+        byte[] soName = map.get(digest);
+        if (soName)
+          {
+            String SharedLibraryName = new String(soName);
+
+BUGS/FEATURES:
+        remove() isn't written yet.
+
+	we can't change the capacity of a PersistentByteMap.
+
+        0x12345678 is a bad choice for the magic number.
+
+        capacity is fixed once the map has been created.
+
+        We use linear probing to resolve collisions.  It might be
+        better to use a scheme that results in fewer probes to
+        determine that an item isn't found.  However, even when the
+        table is half full there are only on average 1.5 probes for a
+        successful search and 2.5 probes for an unsuccessful one.
+
+        We don't use unique strings.  This wastes space.
+
+        capacity should probably be prime, but we don't check that.
+
+	we don't do any locking at all: adding to a PersistentByteMap
+	at runtime is possible, but it requires filesystem locks
+	around get(), put(), and remove().
+*/
+
+package gnu.gcj.runtime;
+
+import java.io.*;
+import java.nio.*;
+import java.nio.channels.*;
+import java.util.*;
+import java.security.MessageDigest;
+
+public class PersistentByteMap
+{
+  private MappedByteBuffer buf;
+
+  static private final int MAGIC = 0;
+  static private final int VERSION = 4;
+  static private final int CAPACITY = 8;
+  static private final int TABLE_BASE = 12;
+  static private final int STRING_BASE = 16;
+  static private final int STRING_SIZE = 20;
+  static private final int FILE_SIZE = 24;
+  static private final int ELEMENTS = 28;
+  
+  static private final int INT_SIZE = 4;
+
+  static private final int TABLE_ENTRY_SIZE = 2 * INT_SIZE;
+
+  private int capacity;   // number of entries
+  private int table_base;   // offset from start of file, in bytes
+  private int string_base;  // offset from start of file, in bytes
+  private int string_size;  // size of string table, in bytes
+  private int file_size;    // size of file, in bytes;
+  private int elements;     // number of elements in table
+
+  private long length;      // the length of the underlying file
+
+  static private final int UNUSED_ENTRY = -1; 
+
+  static public final int KEYS = 0;
+  static public final int VALUES = 1;
+  static public final int ENTRIES = 2;
+
+  static final public class AccessMode
+  {
+    private final FileChannel.MapMode mapMode;
+
+    static
+    {
+      READ_ONLY = new AccessMode(FileChannel.MapMode.READ_ONLY);
+      READ_WRITE = new AccessMode(FileChannel.MapMode.READ_WRITE);
+    }
+
+    public static final AccessMode READ_ONLY;
+    public static final AccessMode READ_WRITE; 
+
+    private AccessMode(FileChannel.MapMode mode)
+    {
+      this.mapMode = mode;
+    }
+  }
+
+  private PersistentByteMap()
+  {
+  }
+
+  public PersistentByteMap(String filename, AccessMode mode)
+    throws IOException 
+  {
+    this(new File(filename), mode);
+  }
+
+  public PersistentByteMap(File f, AccessMode mode)
+    throws IOException 
+  {
+    FileChannel fc;
+
+    if (mode == AccessMode.READ_ONLY)
+      {
+        FileInputStream fis = new FileInputStream(f);
+        fc = fis.getChannel();
+      }
+    else
+      {
+        RandomAccessFile fos = new RandomAccessFile(f, "rw");
+        fc = fos.getChannel();
+      }
+
+    length = fc.size();
+    buf = fc.map(mode.mapMode, 0, length);
+
+    int magic = getWord (MAGIC);
+    if (magic != 0x12345678)
+      throw new IllegalArgumentException(f.getName());
+
+    table_base = getWord (TABLE_BASE);
+    capacity = getWord (CAPACITY);
+    string_base = getWord (STRING_BASE);
+    string_size = getWord (STRING_SIZE);
+    file_size = getWord (FILE_SIZE);
+    elements = getWord (ELEMENTS);
+
+    // FIXME:  Insert a bunch of sanity checks here
+  }
+
+  private void init (PersistentByteMap m, File f, int capacity, int strtabSize)
+    throws IOException 
+  {
+    f.createNewFile();
+    RandomAccessFile raf = new RandomAccessFile(f, "rw");
+        
+    this.capacity = capacity;
+    table_base = 64;
+    string_base = table_base + capacity * TABLE_ENTRY_SIZE;
+    string_size = 0;
+    file_size = string_base;
+    elements = 0;
+
+    int totalFileSize = string_base + strtabSize;
+
+    // Create the file; this rounds up the size of the file to a fixed
+    // number of 4k pages.
+    byte[] _4k = new byte[4096];
+    for (long i = 0; i < totalFileSize; i+= 4096)
+      raf.write(_4k);
+        
+    FileChannel fc = raf.getChannel();
+    buf = fc.map(FileChannel.MapMode.READ_WRITE, 0, raf.length());
+
+    for (int i = 0; i < capacity; i++)
+      putKeyPos(UNUSED_ENTRY, i);
+        
+    putWord(0x12345678, MAGIC);
+    putWord(0x01, VERSION);
+    putWord(capacity, CAPACITY);
+    putWord(table_base, TABLE_BASE);
+    putWord(string_base, STRING_BASE);
+    putWord(file_size, FILE_SIZE);
+    putWord(elements, ELEMENTS);
+    buf.force();
+  }     
+
+  static public PersistentByteMap emptyPersistentByteMap(String filename, 
+                                                         int capacity, int strtabSize)
+    throws IOException 
+  {
+    File f = new File(filename);
+    PersistentByteMap m = new PersistentByteMap();
+    m.init(m, f, capacity, strtabSize);
+    return m;
+  }     
+
+  private int getWord (int index)
+  {
+    buf.position(index);
+    byte[] wordBuf = new byte[4];
+    buf.get(wordBuf);
+
+    int result = (int)wordBuf[0]&0xff;
+    result += ((int)wordBuf[1]&0xff) << 8;
+    result += ((int)wordBuf[2]&0xff) << 16;
+    result += ((int)wordBuf[3]&0xff) << 24;
+    return result;
+  }
+
+  private void putWord (int word, int index)
+  {
+    buf.position(index);
+    byte[] wordBuf = new byte[4];
+    wordBuf[0] = (byte)(word);
+    wordBuf[1] = (byte)(word >>> 8);
+    wordBuf[2] = (byte)(word >>> 16);
+    wordBuf[3] = (byte)(word >>> 24);
+    buf.put(wordBuf);
+  }
+
+  public Set entrySet()
+  {
+    return null;
+  }
+
+  private int getBucket(int n)
+  {
+    return table_base + (2*n * INT_SIZE);
+  }
+
+  private int getKeyPos(int n)
+  {
+    return getWord(getBucket(n));
+  }
+  
+  private int getValuePos(int n)
+  {
+    return getWord(getBucket(n) + INT_SIZE);
+  }
+
+  private void putKeyPos(int index, int n)
+  {
+    putWord(index, getBucket(n));
+  }
+
+  private void putValuePos(int index, int n)
+  {
+    putWord(index, getBucket(n) + INT_SIZE);
+  }
+
+  private byte[] getBytes(int n)
+  {
+    int len = getWord (string_base + n);
+    int base = string_base + n + INT_SIZE;
+    byte[] key = new byte[len];
+    buf.position(base);
+    buf.get(key, 0, len);
+    return key;
+  }
+
+  private int hash (byte[] b)
+  {    
+    // We assume that the message digest is evenly distributed, so we
+    // only need to use a few bytes of it as the hash function.
+    long hashIndex 
+      = ((b[0]&0xffL)
+         + ((b[1]&0xffL)<<8) 
+         + ((b[2]&0xffL)<<16) 
+         + ((b[3]&0xffL)<<24));
+    long result = hashIndex % (long)capacity;
+    return (int)result;
+  }
+        
+  public byte[] get(byte[] digest)
+  {
+    int hashIndex = hash(digest);
+
+    do
+      {
+        int k = getKeyPos(hashIndex);
+        if (k == UNUSED_ENTRY)
+          return null;
+
+        if (Arrays.equals ((byte[])digest, getBytes(k)))
+          return getBytes(getValuePos(hashIndex));
+                
+        // Use linear probing to resolve hash collisions.  This may
+        // not be theoretically as good as open addressing, but it has
+        // good cache behviour.
+        hashIndex++;
+        hashIndex %= capacity;
+      }
+    while (true);
+  }
+
+  public void put(byte[] digest, byte[] value)
+    throws IllegalAccessException
+  {
+    int hashIndex = hash(digest);
+
+    // With the the table 2/3 full there will be on average 2 probes
+    // for a successful search and 5 probes for an unsuccessful one.
+    if (elements >= capacity * 2/3)
+      throw new IllegalAccessException("Table Full: " + elements);
+
+    do
+      {
+        int k = getKeyPos(hashIndex);
+        if (k == UNUSED_ENTRY)
+          {
+            int newKey = addBytes(digest);
+            putKeyPos(newKey, hashIndex);
+            int newValue = addBytes(value);
+            putValuePos(newValue, hashIndex);
+            elements++;
+            putWord(elements, ELEMENTS);            
+            return;
+          }
+        else if (Arrays.equals (digest, getBytes(k)))
+          {
+            int newValue = addBytes((byte[])value);
+            putValuePos(newValue, hashIndex);
+            return;
+          }         
+                
+        hashIndex++;
+        hashIndex %= capacity;
+      }
+    while (true);
+  }
+
+  private int addBytes (byte[] data)
+    throws IllegalAccessException
+  {
+    if (data.length + INT_SIZE >= this.length)
+      throw new IllegalAccessException("String table Full");
+
+    int extent = string_base+string_size;
+    int top = extent;
+    putWord(data.length, extent);
+    extent += INT_SIZE;
+    buf.position(extent);
+    buf.put(data, 0, data.length);
+    extent += data.length;
+    extent += INT_SIZE-1;
+    extent &= ~(INT_SIZE-1); // align
+    string_size = extent - string_base;
+    file_size = extent;
+    putWord (string_size, STRING_SIZE);
+    putWord (file_size, FILE_SIZE);
+        
+    return top - string_base;
+  }
+
+  public Iterator iterator(int type)
+  {
+    return new HashIterator(type);
+  }
+
+  public int size()
+  {
+    return elements;
+  }
+
+  public int capacity()
+  {
+    return capacity;
+  }
+
+  private final class HashIterator implements Iterator
+  {
+    /** Current index in the physical hash table. */
+
+    private int idx;
+    private int count;
+    private final int type;
+
+    /**
+     * Construct a new HashIterator with the supplied type.
+     * @param type {@link #KEYS}, {@link #VALUES}, or {@link #ENTRIES}
+     */
+    HashIterator(int type)
+    {
+      this.type = type;
+      count = elements;
+      idx = 0;
+    }
+
+    /**
+     * Returns true if the Iterator has more elements.
+     * @return true if there are more elements
+     * @throws ConcurrentModificationException if the HashMap was modified
+     */
+    public boolean hasNext()
+    {
+      return count > 0;
+    }
+
+    /**
+     * Returns the next element in the Iterator's sequential view.
+     * @return the next element
+     * @throws ConcurrentModificationException if the HashMap was modified
+     * @throws NoSuchElementException if there is none
+     */
+    public Object next()
+    {
+      count--;
+      for (int i = idx; i < capacity; i++)
+        if (getKeyPos(i) != UNUSED_ENTRY)
+          {
+            idx = i+1;
+            if (type == VALUES)
+              return getBytes(getValuePos(i));
+            if (type == KEYS)
+              return getBytes(getKeyPos(i));
+            return new MapEntry(i,
+                                getBytes(getKeyPos(i)),
+                                getBytes(getValuePos(i)));
+          }
+      return null;
+    }    
+
+    /**
+     * Remove from the underlying collection the last element returned
+     * by next (optional operation). This method can be called only
+     * once after each call to <code>next()</code>. It does not affect
+     * what will be returned by subsequent calls to next.
+     *
+     * @throws IllegalStateException if next has not yet been called
+     *         or remove has already been called since the last call
+     *         to next.
+     * @throws UnsupportedOperationException if this Iterator does not
+     *         support the remove operation.
+     */
+     public void remove()
+    {
+      throw new UnsupportedOperationException();
+    }
+  }
+
+  static public final class MapEntry
+  {
+    private final Object key;
+    private final Object value;
+    private final int bucket;
+
+    public MapEntry(int bucket, Object newKey, Object newValue)
+    {
+      this.key = newKey;
+      this.value = newValue;
+      this.bucket = bucket;
+    }
+
+    public final Object getKey()
+    {
+      return key;
+    }
+
+    public final Object getValue()
+    {
+      return value;
+    }
+
+    public final int getBucket()
+    {
+      return bucket;
+    }
+  }
+}
diff --git a/libjava/gnu/gcj/runtime/SharedLibHelper.java b/libjava/gnu/gcj/runtime/SharedLibHelper.java
index 9e170a120be..a0bfe68b83c 100644
--- a/libjava/gnu/gcj/runtime/SharedLibHelper.java
+++ b/libjava/gnu/gcj/runtime/SharedLibHelper.java
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001, 2003  Free Software Foundation
+/* Copyright (C) 2001, 2003, 2004  Free Software Foundation
 
    This file is part of libgcj.
 
@@ -13,6 +13,12 @@ import java.net.MalformedURLException;
 import java.util.HashMap;
 import java.security.*;
 import gnu.gcj.Core;
+import java.util.Set;
+import java.util.Iterator;
+import java.util.HashSet;
+import java.util.HashMap;
+import java.nio.channels.FileChannel;
+import java.io.*;
 
 public class SharedLibHelper
 {
@@ -36,34 +42,82 @@ public class SharedLibHelper
   {
     synchronized (map)
       {
-	WeakReference ref = (WeakReference) map.get(libname);
-	if (ref != null)
-	  return (SharedLibHelper) ref.get();
+	Set s = (Set)map.get(libname);
+	if (s == null)
+	  return null;
+	for (Iterator i=s.iterator(); i.hasNext();)
+	  {
+	    WeakReference ref = (WeakReference)i.next();
+	    if (ref != null)
+	      return (SharedLibHelper) ref.get();
+	  }
 	return null;
       }
   }
 
+  static void copyFile (File in, File out) throws IOException 
+  {
+    FileChannel source = new FileInputStream(in).getChannel();
+    FileChannel destination = new FileOutputStream(out).getChannel();
+    source.transferTo(0, source.size(), destination);
+    source.close();
+    destination.close();
+  }
+
   public static SharedLibHelper findHelper (ClassLoader loader, String libname,
 					    CodeSource source)
   {
     synchronized (map)
       {
 	SharedLibHelper result;
-	WeakReference ref = (WeakReference) map.get(libname);
-	if (ref != null)
+	Set s = (Set)map.get(libname);
+	if (s == null)
+	  {
+	    s = new HashSet();
+	    map.put(libname, s);
+	  }
+	else
 	  {
-	    result = (SharedLibHelper) ref.get();
-	    if (result != null)
+	    for (Iterator i=s.iterator(); i.hasNext();)
 	      {
-		if (result.loader != loader)
-		  // FIXME
-		  throw new UnknownError();
-		return result;
+		WeakReference ref = (WeakReference)i.next();
+		if (ref != null)
+		  {
+		    result = (SharedLibHelper) ref.get();
+		    if (result != null)
+		      {			
+			// A match succeeds if the library is already
+			// loaded by LOADER or any of its ancestors.
+			ClassLoader l = loader;
+			do
+			  {
+			    if (result.loader == l)
+			      return result;
+			    l = l.getParent();
+			  }
+			while (l != null);
+		      }
+		  }
 	      }
-	  }
 
+	    // Oh dear.  We've already mapped this shared library, but
+	    // with a different class loader.  We need to copy it.
+	    try
+	      {
+		File copy 
+		  = File.createTempFile(new File(libname).getName(), 
+					".so", new File ("/tmp"));
+		File src = new File(libname);
+		copyFile (src, copy);
+		libname = copy.getPath();
+	      }
+	    catch (IOException e)
+	      {
+		return null;
+	      }
+	  }
 	result = new SharedLibHelper(libname, loader, source, 0);
-	map.put(libname, new WeakReference(result));
+	s.add(new WeakReference(result));
 	return result;
       }
   }
@@ -73,7 +127,15 @@ public class SharedLibHelper
   public Class findClass(String name)
   {
     ensureInit();
-    return (Class) classMap.get(name);
+    Class result = (Class) classMap.get(name);
+    if (result != null)
+      {
+	// We never want to return a class without its supers linked.
+	// It isn't clear from the spec, but this is what other
+	// implementations do in practice.
+	ensureSupersLinked(result);
+      }
+    return result;
   }
 
   public URL findResource (String name)
@@ -106,6 +168,12 @@ public class SharedLibHelper
 
   native boolean hasResource(String name);
   native void init();
+  native void ensureSupersLinked(Class k);
+
+  public String toString ()
+  {
+    return "shared object " + baseName;
+  }
 
   /** Called during dlopen's processing of the init section. */
   void registerClass(String name, Class cls)
diff --git a/libjava/gnu/gcj/runtime/VMClassLoader.java b/libjava/gnu/gcj/runtime/VMClassLoader.java
index 1fc7081bb78..f9ef872b30a 100644
--- a/libjava/gnu/gcj/runtime/VMClassLoader.java
+++ b/libjava/gnu/gcj/runtime/VMClassLoader.java
@@ -105,7 +105,8 @@ public final class VMClassLoader extends java.net.URLClassLoader
   /** This is overridden to search the internal hash table, which 
    * will only search existing linked-in classes.   This will make
    * the default implementation of loadClass (in ClassLoader) work right.
-   * The implementation of this method is in java/lang/natClassLoader.cc.
+   * The implementation of this method is in
+   * gnu/gcj/runtime/natVMClassLoader.cc.
    */
   protected native Class findClass(String name) 
     throws java.lang.ClassNotFoundException;
diff --git a/libjava/gnu/gcj/runtime/natSharedLibLoader.cc b/libjava/gnu/gcj/runtime/natSharedLibLoader.cc
index 46eef755a09..184692e1040 100644
--- a/libjava/gnu/gcj/runtime/natSharedLibLoader.cc
+++ b/libjava/gnu/gcj/runtime/natSharedLibLoader.cc
@@ -1,6 +1,6 @@
 // natSharedLibLoader.cc - Implementation of SharedLibHelper native methods.
 
-/* Copyright (C) 2001, 2003  Free Software Foundation
+/* Copyright (C) 2001, 2003, 2004  Free Software Foundation
 
    This file is part of libgcj.
 
@@ -12,6 +12,8 @@ details.  */
 
 #include <gcj/cni.h>
 #include <jvm.h>
+#include <execution.h>
+
 #include <gnu/gcj/runtime/SharedLibHelper.h>
 #include <java/io/IOException.h>
 #include <java/lang/UnsupportedOperationException.h>
@@ -30,9 +32,10 @@ typedef void (*CoreHookFunc) (_Jv_core_chain *);
 void
 _Jv_sharedlib_register_hook (jclass cls)
 {
-  curHelper->registerClass(cls->getName(), cls);
   cls->protectionDomain = curHelper->domain;
   cls->loader = curLoader;
+  cls->engine = &_Jv_soleCompiledEngine;
+  curHelper->registerClass(cls->getName(), cls);
 }
 
 static void
@@ -122,3 +125,9 @@ gnu::gcj::runtime::SharedLibHelper::finalize()
   dlclose (handler);
 #endif
 }
+
+void
+gnu::gcj::runtime::SharedLibHelper::ensureSupersLinked(jclass k)
+{
+  _Jv_Linker::wait_for_state (k, JV_STATE_LOADING);
+}
diff --git a/libjava/gnu/gcj/tools/gcj_dbtool/Main.java b/libjava/gnu/gcj/tools/gcj_dbtool/Main.java
new file mode 100644
index 00000000000..a478f934297
--- /dev/null
+++ b/libjava/gnu/gcj/tools/gcj_dbtool/Main.java
@@ -0,0 +1,272 @@
+/* Copyright (C) 2004  Free Software Foundation
+
+   This file is part of libgcj.
+
+This software is copyrighted work licensed under the terms of the
+Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
+details.  */
+
+package gnu.gcj.tools.gcj_dbtool;
+
+
+import gnu.gcj.runtime.PersistentByteMap;
+import java.io.*;
+import java.util.*;
+import java.util.jar.*;
+import java.security.MessageDigest;
+import java.math.BigInteger;
+
+public class Main
+{
+  public static void main (String[] s)
+  {
+    insist (s.length >= 1);
+    if (s[0].equals("-v"))
+      {
+	insist (s.length == 1);
+	System.out.println("jv-dbtool ("
+			   + System.getProperty("java.vm.name")
+			   + ") "
+			   + System.getProperty("java.vm.version"));
+	System.out.println();
+	System.out.println("Copyright 2004 Free Software Foundation, Inc.");
+	System.out.println("This is free software; see the source for copying conditions.  There is NO");
+	System.out.println("warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.");
+	return;
+      }
+
+    if (s[0].equals("-n"))
+      {
+	insist (s.length >= 2 && s.length <= 3);
+
+	int capacity = 32749;
+
+	if (s.length == 3)
+	  {
+	    // The user has explicitly provided a size for the table.
+	    // We're going to make that size prime.  This isn't
+	    // strictly necessary but it can't hurt.
+
+	    BigInteger size = new BigInteger(s[2], 10);
+	    BigInteger two = BigInteger.ONE.add(BigInteger.ONE);
+
+	    if (size.getLowestSetBit() != 0) // A hard way to say isEven()
+	      size = size.add(BigInteger.ONE);
+
+	    while (! size.isProbablePrime(10))
+	      size = size.add(two);
+
+	    capacity = size.intValue();
+
+	    if (capacity <= 2)
+	      {
+		usage();
+		System.exit(1);
+	      }
+	  }
+	    
+	try
+	  {
+	    PersistentByteMap b 
+	      = PersistentByteMap.emptyPersistentByteMap (s[1], capacity, capacity*64);
+	  }
+	catch (Exception e)
+	  {
+	    System.err.println ("error: could not create " 
+				+ s[1] + ": " + e.toString());
+	    System.exit(2);
+	  }
+	return;
+      }
+
+    if (s[0].equals("-a"))
+      {
+	try
+	  {
+	    insist (s.length == 4);
+	    File jar = new File(s[2]);
+	    PersistentByteMap b 
+	      = new PersistentByteMap(new File(s[1]), 
+				      PersistentByteMap.AccessMode.READ_WRITE);
+	    File soFile = new File(s[3]);
+	    if (! soFile.isFile())
+	      throw new IllegalArgumentException(s[3] + " is not a file");
+	    
+	    addJar(jar, b, soFile);
+	  }
+	catch (Exception e)
+	  {
+	    System.err.println ("error: could not update " + s[1] 
+				+ ": " + e.toString());
+	    System.exit(2);
+	  }
+	return;
+      }
+
+    if (s[0].equals("-t"))
+      {
+	try
+	  {
+	    insist (s.length == 2);
+	    PersistentByteMap b 
+	      = new PersistentByteMap(new File(s[1]),
+				      PersistentByteMap.AccessMode.READ_ONLY);
+	    Iterator iterator = b.iterator(PersistentByteMap.ENTRIES);
+	
+	    while (iterator.hasNext())
+	      {
+		PersistentByteMap.MapEntry entry 
+		  = (PersistentByteMap.MapEntry)iterator.next();
+		byte[] key = (byte[])entry.getKey();
+		byte[] value = (byte[])b.get(key);
+		if (! Arrays.equals (value, (byte[])entry.getValue()))
+		  {
+		    String err 
+		      = ("Key " + bytesToString(key) + " at bucket " 
+			 + entry.getBucket());
+		  
+		    throw new RuntimeException(err);
+		  }
+	      }
+	  }
+	catch (Exception e)
+	  {
+	    e.printStackTrace();
+	    System.exit(3);
+	  }
+	return;
+      }
+	 
+    if (s[0].equals("-l"))
+      {
+	insist (s.length == 2);
+	try
+	  {
+	    PersistentByteMap b 
+	      = new PersistentByteMap(new File(s[1]),
+				      PersistentByteMap.AccessMode.READ_ONLY);
+
+	    System.out.println ("Capacity: " + b.capacity());
+	    System.out.println ("Size: " + b.size());
+	    System.out.println ();
+
+	    System.out.println ("Elements: ");
+	    Iterator iterator = b.iterator(PersistentByteMap.ENTRIES);
+    
+	    while (iterator.hasNext())
+	      {
+		PersistentByteMap.MapEntry entry 
+		  = (PersistentByteMap.MapEntry)iterator.next();
+		byte[] digest = (byte[])entry.getKey();
+		System.out.print ("[" + entry.getBucket() + "] " 
+				  + bytesToString(digest)
+				  + " -> ");
+		System.out.println (new String((byte[])entry.getValue()));
+	      }
+	  }
+	catch (Exception e)
+	  {
+	    System.err.println ("error: could not list " 
+				+ s[1] + ": " + e.toString());
+	    System.exit(2);
+	  }
+	return;
+      }
+
+    if (s[0].equals("-d"))
+      {
+	insist (s.length == 2);
+	try
+	  {    
+	    MessageDigest md = MessageDigest.getInstance("MD5");
+	    PersistentByteMap b 
+	      = new PersistentByteMap(new File(s[1]), 
+				      PersistentByteMap.AccessMode.READ_WRITE);
+	    int N = b.capacity();
+	    byte[] bytes = new byte[1];
+	    byte digest[] = md.digest(bytes);
+	    for (int i = 0; i < N; i++)
+	      {
+		digest = md.digest(digest);
+		b.put(digest, digest);
+	      }
+	  }
+	catch (Exception e)
+	  {
+	    e.printStackTrace();
+	    System.exit(3);
+	  }	    
+	return;
+      }
+    
+    usage();
+    System.exit(1);	    
+  }
+
+  private static void insist(boolean ok)
+  {
+    if (! ok)
+      {
+	usage();
+	System.exit(1);
+      }	    
+  }
+
+  private static void usage()
+  {
+    System.err.println
+      ("jv-dbtool: Manipulate gcj map database files\n"
+       + "\n"
+       + "  Usage: \n"
+       + "    jv-dbtool -n file.gcjdb [size]     - Create a new gcj map database\n"
+       + "    jv-dbtool -a file.gcjdb file.jar file.so\n"
+       + "            - Add the contents of file.jar to the database\n"
+       + "    jv-dbtool -t file.gcjdb            - Test a gcj map database\n"
+       + "    jv-dbtool -l file.gcjdb            - List a gcj map database\n");
+  }
+      
+
+  private static void addJar(File f, PersistentByteMap b, File soFile)
+   throws Exception
+  {
+    MessageDigest md = MessageDigest.getInstance("MD5");
+
+    JarFile jar = new JarFile (f);
+    Enumeration entries = jar.entries();
+
+    while (entries.hasMoreElements())
+      {
+	JarEntry classfile = (JarEntry)entries.nextElement();
+	if (classfile.getName().endsWith(".class"))
+	  {
+	    InputStream str = jar.getInputStream(classfile);
+	    long length = classfile.getSize();
+	    if (length == -1)
+	      throw new EOFException();
+
+	    byte[] data = new byte[length];
+	    int pos = 0;
+	    while (length - pos > 0)
+	      {
+		int len = str.read(data, pos, (int)(length - pos));
+		if (len == -1)
+		  throw new EOFException("Not enough data reading from: "
+					 + classfile.getName());
+		pos += len;
+	      }
+	    b.put(md.digest(data), 
+		  soFile.getCanonicalPath().getBytes());
+	  }
+      }	      
+  }    
+
+  static String bytesToString(byte[] b)
+  {
+    StringBuffer hexBytes = new StringBuffer();
+    int length = b.length;
+    for (int i = 0; i < length; ++i)
+      hexBytes.append(Integer.toHexString(b[i] & 0xff));
+    return hexBytes.toString();
+  }
+}
+