--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/agent/src/share/classes/sun/jvm/hotspot/interpreter/BytecodeLoadConstant.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,176 @@
+/*
+ * Copyright 2002-2003 Sun Microsystems, Inc.  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.
+ *
+ * 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+package sun.jvm.hotspot.interpreter;
+
+import sun.jvm.hotspot.oops.*;
+import sun.jvm.hotspot.utilities.*;
+
+public class BytecodeLoadConstant extends BytecodeWithCPIndex {
+  BytecodeLoadConstant(Method method, int bci) {
+    super(method, bci);
+  }
+
+  public int index() {
+    return javaCode() == Bytecodes._ldc ?
+                 (int) (0xFF & javaByteAt(1))
+               : (int) (0xFFFF & javaShortAt(1));
+  }
+
+  public void verify() {
+    if (Assert.ASSERTS_ENABLED) {
+      Assert.that(isValid(), "check load constant");
+    }
+  }
+
+  public boolean isValid() {
+    int jcode = javaCode();
+    boolean codeOk = jcode == Bytecodes._ldc || jcode == Bytecodes._ldc_w ||
+           jcode == Bytecodes._ldc2_w;
+    if (! codeOk) return false;
+
+    ConstantTag ctag = method().getConstants().getTagAt(index());
+    if (jcode == Bytecodes._ldc2_w) {
+       // has to be double or long
+       return (ctag.isDouble() || ctag.isLong()) ? true: false;
+    } else {
+       // has to be int or float or String or Klass
+       return (ctag.isUnresolvedString() || ctag.isString()
+               || ctag.isUnresolvedKlass() || ctag.isKlass()
+               || ctag.isInt() || ctag.isFloat())? true: false;
+    }
+  }
+
+  public boolean isKlassConstant() {
+    int jcode = javaCode();
+    if (jcode == Bytecodes._ldc2_w) {
+       return false;
+    }
+
+    ConstantTag ctag = method().getConstants().getTagAt(index());
+    return ctag.isKlass() || ctag.isUnresolvedKlass();
+  }
+
+  // return Symbol (if unresolved) or Klass (if resolved)
+  public Oop getKlass() {
+    if (Assert.ASSERTS_ENABLED) {
+      Assert.that(isKlassConstant(), "not a klass literal");
+    }
+    // tag change from 'unresolved' to 'klass' does not happen atomically.
+    // We just look at the object at the corresponding index and
+    // decide based on the oop type.
+    ConstantPool cpool = method().getConstants();
+    int cpIndex = index();
+    Oop oop = cpool.getObjAt(cpIndex);
+    if (oop.isKlass()) {
+       return (Klass) oop;
+    } else if (oop.isSymbol()) {
+       return (Symbol) oop;
+    } else {
+       throw new RuntimeException("should not reach here");
+    }
+  }
+
+  public static BytecodeLoadConstant at(Method method, int bci) {
+    BytecodeLoadConstant b = new BytecodeLoadConstant(method, bci);
+    if (Assert.ASSERTS_ENABLED) {
+      b.verify();
+    }
+    return b;
+  }
+
+  /** Like at, but returns null if the BCI is not at ldc or ldc_w or ldc2_w  */
+  public static BytecodeLoadConstant atCheck(Method method, int bci) {
+    BytecodeLoadConstant b = new BytecodeLoadConstant(method, bci);
+    return (b.isValid() ? b : null);
+  }
+
+  public static BytecodeLoadConstant at(BytecodeStream bcs) {
+    return new BytecodeLoadConstant(bcs.method(), bcs.bci());
+  }
+
+  public String getConstantValue() {
+    ConstantPool cpool = method().getConstants();
+    int cpIndex = index();
+    ConstantTag ctag = cpool.getTagAt(cpIndex);
+    if (ctag.isInt()) {
+       return "<int " + Integer.toString(cpool.getIntAt(cpIndex)) +">";
+    } else if (ctag.isLong()) {
+       return "<long " + Long.toString(cpool.getLongAt(cpIndex)) + "L>";
+    } else if (ctag.isFloat()) {
+       return "<float " + Float.toString(cpool.getFloatAt(cpIndex)) + "F>";
+    } else if (ctag.isDouble()) {
+       return "<double " + Double.toString(cpool.getDoubleAt(cpIndex)) + "D>";
+    } else if (ctag.isString() || ctag.isUnresolvedString()) {
+       // tag change from 'unresolved' to 'string' does not happen atomically.
+       // We just look at the object at the corresponding index and
+       // decide based on the oop type.
+       Oop obj = cpool.getObjAt(cpIndex);
+       if (obj.isSymbol()) {
+          Symbol sym = (Symbol) obj;
+          return "<String \"" + sym.asString() + "\">";
+       } else if (obj.isInstance()) {
+          return "<String \"" + OopUtilities.stringOopToString(obj) + "\">";
+       } else {
+          throw new RuntimeException("should not reach here");
+       }
+    } else if (ctag.isKlass() || ctag.isUnresolvedKlass()) {
+       // tag change from 'unresolved' to 'klass' does not happen atomically.
+       // We just look at the object at the corresponding index and
+       // decide based on the oop type.
+       Oop obj = cpool.getObjAt(cpIndex);
+       if (obj.isKlass()) {
+          Klass k = (Klass) obj;
+          return "<Class " + k.getName().asString() + "@" + k.getHandle() + ">";
+       } else if (obj.isSymbol()) {
+          Symbol sym = (Symbol) obj;
+          return "<Class " + sym.asString() + ">";
+       } else {
+          throw new RuntimeException("should not reach here");
+       }
+    } else {
+       if (Assert.ASSERTS_ENABLED) {
+         Assert.that(false, "invalid load constant type");
+       }
+       return null;
+    }
+  }
+
+  public String toString() {
+    StringBuffer buf = new StringBuffer();
+    buf.append(getJavaBytecodeName());
+    buf.append(spaces);
+    buf.append('#');
+    buf.append(Integer.toString(index()));
+    buf.append(spaces);
+    buf.append(getConstantValue());
+    if (code() != javaCode()) {
+       buf.append(spaces);
+       buf.append('[');
+       buf.append(getBytecodeName());
+       buf.append(']');
+    }
+    return buf.toString();
+  }
+}