move proxy and annotation code from C++ to Java

This allows code shrinkers to remove it if it's not used by the application.

classpath/avian/SystemClassLoader.java

@@ -10,10 +10,23 @@
 
 package avian;
 
+import static avian.Stream.read1;
+import static avian.Stream.read2;
+
+import java.lang.reflect.Method;
+import java.lang.reflect.Field;
 import java.net.URL;
 import java.net.MalformedURLException;
+import java.io.InputStream;
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
 
 public class SystemClassLoader extends ClassLoader {
+  private static final int LinkFlag = 1 << 8;
+
+  public static native Class defineClass
+    (ClassLoader loader, byte[] b, int offset, int length);
+
   protected native Class findClass(String name) throws ClassNotFoundException;
 
   protected native Class findLoadedClass(String name);
@@ -28,4 +41,225 @@ public class SystemClassLoader extends ClassLoader {
     }
     return null;
   }
+
+  private static Class loadClass(ClassLoader loader,
+                                 byte[] nameBytes, int offset, int length)
+  {
+    String name = new String(nameBytes, offset, length, false);
+    try {
+      return loader.loadClass(name);
+    } catch (ClassNotFoundException e) {
+      NoClassDefFoundError error = new NoClassDefFoundError(name);
+      error.initCause(e);
+      throw error;
+    }
+  }
+
+  private static Object parseAnnotationValue(ClassLoader loader,
+                                             Object pool,
+                                             InputStream in)
+    throws IOException
+  {
+    switch (read1(in)) {
+    case 'Z':
+      return Boolean.valueOf(Singleton.getInt(pool, read2(in) - 1) != 0);
+
+    case 'B':
+      return Byte.valueOf((byte) Singleton.getInt(pool, read2(in) - 1));
+
+    case 'C':
+      return Character.valueOf((char) Singleton.getInt(pool, read2(in) - 1));
+
+    case 'S':
+      return Short.valueOf((short) Singleton.getInt(pool, read2(in) - 1));
+
+    case 'I':
+      return Integer.valueOf(Singleton.getInt(pool, read2(in) - 1));
+
+    case 'F':
+      return Float.valueOf
+        (Float.intBitsToFloat(Singleton.getInt(pool, read2(in) - 1)));
+
+    case 'J': {
+      return Long.valueOf(Singleton.getLong(pool, read2(in) - 1));
+    }
+
+    case 'D': {
+      return Double.valueOf
+        (Double.longBitsToDouble(Singleton.getLong(pool, read2(in) - 1)));
+    }
+
+    case 's': {
+      byte[] data = (byte[]) Singleton.getObject(pool, read2(in) - 1);
+
+      return new String(data, 0, data.length - 1, false);
+    }
+
+    case 'e': {
+      byte[] typeName = (byte[]) Singleton.getObject(pool, read2(in) - 1);
+      byte[] name = (byte[]) Singleton.getObject(pool, read2(in) - 1);
+
+      return Enum.valueOf
+        (loadClass(loader, typeName, 1, typeName.length - 3),
+         new String(name, 0, name.length - 1, false));
+    }
+
+    case 'c':{
+      byte[] name = (byte[]) Singleton.getObject(pool, read2(in) - 1);
+
+      return loadClass(loader, name, 1, name.length - 3);
+    }
+
+    case '@':
+      return parseAnnotation(loader, pool, in);
+
+    case '[': {
+      Object[] array = new Object[read2(in)];
+      for (int i = 0; i < array.length; ++i) {
+        array[i] = parseAnnotationValue(loader, pool, in);
+      }
+      return array;
+    }    
+
+    default: throw new AssertionError();
+    }
+  }
+
+  private static Object[] parseAnnotation(ClassLoader loader,
+                                          Object pool,
+                                          InputStream in)
+    throws IOException
+  {
+    byte[] typeName = (byte[]) Singleton.getObject(pool, read2(in) - 1);
+    Object[] annotation = new Object[(read2(in) + 1) * 2];
+    annotation[1] = loadClass(loader, typeName, 1, typeName.length - 3);
+
+    for (int i = 2; i < annotation.length; i += 2) {
+      byte[] name = (byte[]) Singleton.getObject(pool, read2(in) - 1);
+      annotation[i] = new String(name, 0, name.length - 1, false);
+      annotation[i + 1] = parseAnnotationValue(loader, pool, in);
+    }
+
+    return annotation;
+  }
+
+  private static Object[] parseAnnotationTable(ClassLoader loader,
+                                               Object pool,
+                                               InputStream in)
+    throws IOException
+  {
+    Object[] table = new Object[read2(in)];
+    for (int i = 0; i < table.length; ++i) {
+      table[i] = parseAnnotation(loader, pool, in);
+    }
+    return table;
+  }
+
+  private static void parseAnnotationTable(ClassLoader loader,
+                                           Addendum addendum)
+  {
+    if (addendum != null && addendum.annotationTable != null) {
+      try {
+        addendum.annotationTable = parseAnnotationTable
+          (loader, addendum.pool, new ByteArrayInputStream
+           ((byte[]) addendum.annotationTable));
+      } catch (IOException e) {
+        AssertionError error = new AssertionError();
+        error.initCause(e);
+        throw error;
+      }
+
+      addendum.pool = null;
+    }
+  }
+
+  private static int resolveSpec(ClassLoader loader, byte[] spec, int start) {
+    int result;
+    int end;
+    switch (spec[start]) {
+    case 'L':
+      ++ start;
+      end = start;
+      while (spec[end] != ';') ++ end;
+      result = end + 1;
+      break;
+
+    case '[':
+      end = start + 1;
+      while (spec[end] == '[') ++ end;
+      switch (spec[end]) {
+      case 'L':
+        ++ end;
+        while (spec[end] != ';') ++ end;
+        ++ end;
+        break;
+        
+      default:
+        ++ end;
+      }
+      result = end;
+      break;
+
+    default:
+      return start + 1;
+    }
+
+    loadClass(loader, spec, start, end - start);
+
+    return result;
+  }
+
+  private static native void acquireClassLock();
+
+  private static native void releaseClassLock();
+
+  public static void link(Class c, ClassLoader loader) {
+    acquireClassLock();
+    try {
+      if ((c.vmFlags & LinkFlag) == 0) {
+        if (c.super_ != null) {
+          link(c.super_, loader);
+        }
+
+        parseAnnotationTable(loader, c.addendum);
+
+        if (c.interfaceTable != null) {
+          int stride = (c.isInterface() ? 1 : 2);
+          for (int i = 0; i < c.interfaceTable.length; i += stride) {
+            link((Class) c.interfaceTable[i], loader);
+          }
+        }
+
+        if (c.methodTable != null) {
+          for (int i = 0; i < c.methodTable.length; ++i) {
+            Method m = c.methodTable[i];
+
+            for (int j = 1; j < m.spec.length;) {
+              j = resolveSpec(loader, m.spec, j);
+            }
+
+            parseAnnotationTable(loader, m.addendum);
+          }
+        }
+
+        if (c.fieldTable != null) {
+          for (int i = 0; i < c.fieldTable.length; ++i) {
+            Field f = c.fieldTable[i];
+
+            resolveSpec(loader, f.spec, 0);
+
+            parseAnnotationTable(loader, f.addendum);
+          }
+        }
+
+        c.vmFlags |= LinkFlag;
+      }
+    } finally {
+      releaseClassLock();
+    }
+  }
+
+  public static void link(Class c) {
+    link(c, c.getClassLoader());
+  }
 }