--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/oops/constantPoolOop.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,1269 @@
+/*
+ * Copyright 1997-2006 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.
+ *
+ */
+
+# include "incls/_precompiled.incl"
+# include "incls/_constantPoolOop.cpp.incl"
+
+klassOop constantPoolOopDesc::klass_at_impl(constantPoolHandle this_oop, int which, TRAPS) {
+  // A resolved constantPool entry will contain a klassOop, otherwise a symbolOop.
+  // It is not safe to rely on the tag bit's here, since we don't have a lock, and the entry and
+  // tag is not updated atomicly.
+  oop entry = *(this_oop->obj_at_addr(which));
+  if (entry->is_klass()) {
+    // Already resolved - return entry.
+    return (klassOop)entry;
+  }
+
+  // Acquire lock on constant oop while doing update. After we get the lock, we check if another object
+  // already has updated the object
+  assert(THREAD->is_Java_thread(), "must be a Java thread");
+  bool do_resolve = false;
+  bool in_error = false;
+
+  symbolHandle name;
+  Handle       loader;
+  { ObjectLocker ol(this_oop, THREAD);
+
+    if (this_oop->tag_at(which).is_unresolved_klass()) {
+      if (this_oop->tag_at(which).is_unresolved_klass_in_error()) {
+        in_error = true;
+      } else {
+        do_resolve = true;
+        name   = symbolHandle(THREAD, this_oop->unresolved_klass_at(which));
+        loader = Handle(THREAD, instanceKlass::cast(this_oop->pool_holder())->class_loader());
+      }
+    }
+  } // unlocking constantPool
+
+
+  // The original attempt to resolve this constant pool entry failed so find the
+  // original error and throw it again (JVMS 5.4.3).
+  if (in_error) {
+    symbolOop error = SystemDictionary::find_resolution_error(this_oop, which);
+    guarantee(error != (symbolOop)NULL, "tag mismatch with resolution error table");
+    ResourceMark rm;
+    // exception text will be the class name
+    const char* className = this_oop->unresolved_klass_at(which)->as_C_string();
+    THROW_MSG_0(error, className);
+  }
+
+  if (do_resolve) {
+    // this_oop must be unlocked during resolve_or_fail
+    oop protection_domain = Klass::cast(this_oop->pool_holder())->protection_domain();
+    Handle h_prot (THREAD, protection_domain);
+    klassOop k_oop = SystemDictionary::resolve_or_fail(name, loader, h_prot, true, THREAD);
+    KlassHandle k;
+    if (!HAS_PENDING_EXCEPTION) {
+      k = KlassHandle(THREAD, k_oop);
+      // Do access check for klasses
+      verify_constant_pool_resolve(this_oop, k, THREAD);
+    }
+
+    // Failed to resolve class. We must record the errors so that subsequent attempts
+    // to resolve this constant pool entry fail with the same error (JVMS 5.4.3).
+    if (HAS_PENDING_EXCEPTION) {
+      ResourceMark rm;
+      symbolHandle error(PENDING_EXCEPTION->klass()->klass_part()->name());
+
+      bool throw_orig_error = false;
+      {
+        ObjectLocker ol (this_oop, THREAD);
+
+        // some other thread has beaten us and has resolved the class.
+        if (this_oop->tag_at(which).is_klass()) {
+          CLEAR_PENDING_EXCEPTION;
+          entry = this_oop->resolved_klass_at(which);
+          return (klassOop)entry;
+        }
+
+        if (!PENDING_EXCEPTION->
+              is_a(SystemDictionary::linkageError_klass())) {
+          // Just throw the exception and don't prevent these classes from
+          // being loaded due to virtual machine errors like StackOverflow
+          // and OutOfMemoryError, etc, or if the thread was hit by stop()
+          // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
+        }
+        else if (!this_oop->tag_at(which).is_unresolved_klass_in_error()) {
+          SystemDictionary::add_resolution_error(this_oop, which, error);
+          this_oop->tag_at_put(which, JVM_CONSTANT_UnresolvedClassInError);
+        } else {
+          // some other thread has put the class in error state.
+          error = symbolHandle(SystemDictionary::find_resolution_error(this_oop, which));
+          assert(!error.is_null(), "checking");
+          throw_orig_error = true;
+        }
+      } // unlocked
+
+      if (throw_orig_error) {
+        CLEAR_PENDING_EXCEPTION;
+        ResourceMark rm;
+        const char* className = this_oop->unresolved_klass_at(which)->as_C_string();
+        THROW_MSG_0(error, className);
+      }
+
+      return 0;
+    }
+
+    if (TraceClassResolution && !k()->klass_part()->oop_is_array()) {
+      // skip resolving the constant pool so that this code get's
+      // called the next time some bytecodes refer to this class.
+      ResourceMark rm;
+      int line_number = -1;
+      const char * source_file = NULL;
+      if (JavaThread::current()->has_last_Java_frame()) {
+        // try to identify the method which called this function.
+        vframeStream vfst(JavaThread::current());
+        if (!vfst.at_end()) {
+          line_number = vfst.method()->line_number_from_bci(vfst.bci());
+          symbolOop s = instanceKlass::cast(vfst.method()->method_holder())->source_file_name();
+          if (s != NULL) {
+            source_file = s->as_C_string();
+          }
+        }
+      }
+      if (k() != this_oop->pool_holder()) {
+        // only print something if the classes are different
+        if (source_file != NULL) {
+          tty->print("RESOLVE %s %s %s:%d\n",
+                     instanceKlass::cast(this_oop->pool_holder())->external_name(),
+                     instanceKlass::cast(k())->external_name(), source_file, line_number);
+        } else {
+          tty->print("RESOLVE %s %s\n",
+                     instanceKlass::cast(this_oop->pool_holder())->external_name(),
+                     instanceKlass::cast(k())->external_name());
+        }
+      }
+      return k();
+    } else {
+      ObjectLocker ol (this_oop, THREAD);
+      // Only updated constant pool - if it is resolved.
+      do_resolve = this_oop->tag_at(which).is_unresolved_klass();
+      if (do_resolve) {
+        this_oop->klass_at_put(which, k());
+      }
+    }
+  }
+
+  entry = this_oop->resolved_klass_at(which);
+  assert(entry->is_klass(), "must be resolved at this point");
+  return (klassOop)entry;
+}
+
+
+// Does not update constantPoolOop - to avoid any exception throwing. Used
+// by compiler and exception handling.  Also used to avoid classloads for
+// instanceof operations. Returns NULL if the class has not been loaded or
+// if the verification of constant pool failed
+klassOop constantPoolOopDesc::klass_at_if_loaded(constantPoolHandle this_oop, int which) {
+  oop entry = *this_oop->obj_at_addr(which);
+  if (entry->is_klass()) {
+    return (klassOop)entry;
+  } else {
+    assert(entry->is_symbol(), "must be either symbol or klass");
+    Thread *thread = Thread::current();
+    symbolHandle name (thread, (symbolOop)entry);
+    oop loader = instanceKlass::cast(this_oop->pool_holder())->class_loader();
+    oop protection_domain = Klass::cast(this_oop->pool_holder())->protection_domain();
+    Handle h_prot (thread, protection_domain);
+    Handle h_loader (thread, loader);
+    klassOop k = SystemDictionary::find(name, h_loader, h_prot, thread);
+
+    if (k != NULL) {
+      // Make sure that resolving is legal
+      EXCEPTION_MARK;
+      KlassHandle klass(THREAD, k);
+      // return NULL if verification fails
+      verify_constant_pool_resolve(this_oop, klass, THREAD);
+      if (HAS_PENDING_EXCEPTION) {
+        CLEAR_PENDING_EXCEPTION;
+        return NULL;
+      }
+      return klass();
+    } else {
+      return k;
+    }
+  }
+}
+
+
+klassOop constantPoolOopDesc::klass_ref_at_if_loaded(constantPoolHandle this_oop, int which) {
+  return klass_at_if_loaded(this_oop, this_oop->klass_ref_index_at(which));
+}
+
+
+// This is an interface for the compiler that allows accessing non-resolved entries
+// in the constant pool - but still performs the validations tests. Must be used
+// in a pre-parse of the compiler - to determine what it can do and not do.
+// Note: We cannot update the ConstantPool from the vm_thread.
+klassOop constantPoolOopDesc::klass_ref_at_if_loaded_check(constantPoolHandle this_oop, int index, TRAPS) {
+  int which = this_oop->klass_ref_index_at(index);
+  oop entry = *this_oop->obj_at_addr(which);
+  if (entry->is_klass()) {
+    return (klassOop)entry;
+  } else {
+    assert(entry->is_symbol(), "must be either symbol or klass");
+    symbolHandle name (THREAD, (symbolOop)entry);
+    oop loader = instanceKlass::cast(this_oop->pool_holder())->class_loader();
+    oop protection_domain = Klass::cast(this_oop->pool_holder())->protection_domain();
+    Handle h_loader(THREAD, loader);
+    Handle h_prot  (THREAD, protection_domain);
+    KlassHandle k(THREAD, SystemDictionary::find(name, h_loader, h_prot, THREAD));
+
+    // Do access check for klasses
+    if( k.not_null() ) verify_constant_pool_resolve(this_oop, k, CHECK_NULL);
+    return k();
+  }
+}
+
+
+symbolOop constantPoolOopDesc::uncached_name_ref_at(int which) {
+  jint ref_index = name_and_type_at(uncached_name_and_type_ref_index_at(which));
+  int name_index = extract_low_short_from_int(ref_index);
+  return symbol_at(name_index);
+}
+
+
+symbolOop constantPoolOopDesc::uncached_signature_ref_at(int which) {
+  jint ref_index = name_and_type_at(uncached_name_and_type_ref_index_at(which));
+  int signature_index = extract_high_short_from_int(ref_index);
+  return symbol_at(signature_index);
+}
+
+
+int constantPoolOopDesc::uncached_name_and_type_ref_index_at(int which) {
+  jint ref_index = field_or_method_at(which, true);
+  return extract_high_short_from_int(ref_index);
+}
+
+
+int constantPoolOopDesc::uncached_klass_ref_index_at(int which) {
+  jint ref_index = field_or_method_at(which, true);
+  return extract_low_short_from_int(ref_index);
+}
+
+
+void constantPoolOopDesc::verify_constant_pool_resolve(constantPoolHandle this_oop, KlassHandle k, TRAPS) {
+ if (k->oop_is_instance() || k->oop_is_objArray()) {
+    instanceKlassHandle holder (THREAD, this_oop->pool_holder());
+    klassOop elem_oop = k->oop_is_instance() ? k() : objArrayKlass::cast(k())->bottom_klass();
+    KlassHandle element (THREAD, elem_oop);
+
+    // The element type could be a typeArray - we only need the access check if it is
+    // an reference to another class
+    if (element->oop_is_instance()) {
+      LinkResolver::check_klass_accessability(holder, element, CHECK);
+    }
+  }
+}
+
+
+int constantPoolOopDesc::klass_ref_index_at(int which) {
+  jint ref_index = field_or_method_at(which, false);
+  return extract_low_short_from_int(ref_index);
+}
+
+
+int constantPoolOopDesc::name_and_type_ref_index_at(int which) {
+  jint ref_index = field_or_method_at(which, false);
+  return extract_high_short_from_int(ref_index);
+}
+
+
+int constantPoolOopDesc::name_ref_index_at(int which) {
+  jint ref_index = name_and_type_at(which);
+  return extract_low_short_from_int(ref_index);
+}
+
+
+int constantPoolOopDesc::signature_ref_index_at(int which) {
+  jint ref_index = name_and_type_at(which);
+  return extract_high_short_from_int(ref_index);
+}
+
+
+klassOop constantPoolOopDesc::klass_ref_at(int which, TRAPS) {
+  return klass_at(klass_ref_index_at(which), CHECK_NULL);
+}
+
+
+symbolOop constantPoolOopDesc::klass_name_at(int which) {
+  assert(tag_at(which).is_unresolved_klass() || tag_at(which).is_klass(),
+         "Corrupted constant pool");
+  // A resolved constantPool entry will contain a klassOop, otherwise a symbolOop.
+  // It is not safe to rely on the tag bit's here, since we don't have a lock, and the entry and
+  // tag is not updated atomicly.
+  oop entry = *(obj_at_addr(which));
+  if (entry->is_klass()) {
+    // Already resolved - return entry's name.
+    return klassOop(entry)->klass_part()->name();
+  } else {
+    assert(entry->is_symbol(), "must be either symbol or klass");
+    return (symbolOop)entry;
+  }
+}
+
+symbolOop constantPoolOopDesc::klass_ref_at_noresolve(int which) {
+  jint ref_index = klass_ref_index_at(which);
+  return klass_at_noresolve(ref_index);
+}
+
+char* constantPoolOopDesc::string_at_noresolve(int which) {
+  // Test entry type in case string is resolved while in here.
+  oop entry = *(obj_at_addr(which));
+  if (entry->is_symbol()) {
+    return ((symbolOop)entry)->as_C_string();
+  } else {
+    return java_lang_String::as_utf8_string(entry);
+  }
+}
+
+
+symbolOop constantPoolOopDesc::name_ref_at(int which) {
+  jint ref_index = name_and_type_at(name_and_type_ref_index_at(which));
+  int name_index = extract_low_short_from_int(ref_index);
+  return symbol_at(name_index);
+}
+
+
+symbolOop constantPoolOopDesc::signature_ref_at(int which) {
+  jint ref_index = name_and_type_at(name_and_type_ref_index_at(which));
+  int signature_index = extract_high_short_from_int(ref_index);
+  return symbol_at(signature_index);
+}
+
+
+BasicType constantPoolOopDesc::basic_type_for_signature_at(int which) {
+  return FieldType::basic_type(symbol_at(which));
+}
+
+
+void constantPoolOopDesc::resolve_string_constants_impl(constantPoolHandle this_oop, TRAPS) {
+  for (int index = 1; index < this_oop->length(); index++) { // Index 0 is unused
+    if (this_oop->tag_at(index).is_unresolved_string()) {
+      this_oop->string_at(index, CHECK);
+    }
+  }
+}
+
+oop constantPoolOopDesc::string_at_impl(constantPoolHandle this_oop, int which, TRAPS) {
+  oop entry = *(this_oop->obj_at_addr(which));
+  if (entry->is_symbol()) {
+    ObjectLocker ol(this_oop, THREAD);
+    if (this_oop->tag_at(which).is_unresolved_string()) {
+      // Intern string
+      symbolOop sym = this_oop->unresolved_string_at(which);
+      entry = StringTable::intern(sym, CHECK_(constantPoolOop(NULL)));
+      this_oop->string_at_put(which, entry);
+    } else {
+      // Another thread beat us and interned string, read string from constant pool
+      entry = this_oop->resolved_string_at(which);
+    }
+  }
+  assert(java_lang_String::is_instance(entry), "must be string");
+  return entry;
+}
+
+
+bool constantPoolOopDesc::klass_name_at_matches(instanceKlassHandle k,
+                                                int which) {
+  // Names are interned, so we can compare symbolOops directly
+  symbolOop cp_name = klass_name_at(which);
+  return (cp_name == k->name());
+}
+
+
+int constantPoolOopDesc::pre_resolve_shared_klasses(TRAPS) {
+  ResourceMark rm;
+  int count = 0;
+  for (int index = 1; index < tags()->length(); index++) { // Index 0 is unused
+    if (tag_at(index).is_unresolved_string()) {
+      // Intern string
+      symbolOop sym = unresolved_string_at(index);
+      oop entry = StringTable::intern(sym, CHECK_(-1));
+      string_at_put(index, entry);
+    }
+  }
+  return count;
+}
+
+
+// Iterate over symbols which are used as class, field, method names and
+// signatures (in preparation for writing to the shared archive).
+
+void constantPoolOopDesc::shared_symbols_iterate(OopClosure* closure) {
+  for (int index = 1; index < length(); index++) { // Index 0 is unused
+    switch (tag_at(index).value()) {
+
+    case JVM_CONSTANT_UnresolvedClass:
+      closure->do_oop(obj_at_addr(index));
+      break;
+
+    case JVM_CONSTANT_NameAndType:
+      {
+        int i = *int_at_addr(index);
+        closure->do_oop(obj_at_addr((unsigned)i >> 16));
+        closure->do_oop(obj_at_addr((unsigned)i & 0xffff));
+      }
+      break;
+
+    case JVM_CONSTANT_Class:
+    case JVM_CONSTANT_InterfaceMethodref:
+    case JVM_CONSTANT_Fieldref:
+    case JVM_CONSTANT_Methodref:
+    case JVM_CONSTANT_Integer:
+    case JVM_CONSTANT_Float:
+      // Do nothing!  Not an oop.
+      // These constant types do not reference symbols at this point.
+      break;
+
+    case JVM_CONSTANT_String:
+      // Do nothing!  Not a symbol.
+      break;
+
+    case JVM_CONSTANT_UnresolvedString:
+    case JVM_CONSTANT_Utf8:
+      // These constants are symbols, but unless these symbols are
+      // actually to be used for something, we don't want to mark them.
+      break;
+
+    case JVM_CONSTANT_Long:
+    case JVM_CONSTANT_Double:
+      // Do nothing!  Not an oop. (But takes two pool entries.)
+      ++index;
+      break;
+
+    default:
+      ShouldNotReachHere();
+      break;
+    }
+  }
+}
+
+
+// Iterate over the [one] tags array (in preparation for writing to the
+// shared archive).
+
+void constantPoolOopDesc::shared_tags_iterate(OopClosure* closure) {
+  closure->do_oop(tags_addr());
+}
+
+
+// Iterate over String objects (in preparation for writing to the shared
+// archive).
+
+void constantPoolOopDesc::shared_strings_iterate(OopClosure* closure) {
+  for (int index = 1; index < length(); index++) { // Index 0 is unused
+    switch (tag_at(index).value()) {
+
+    case JVM_CONSTANT_UnresolvedClass:
+    case JVM_CONSTANT_NameAndType:
+      // Do nothing!  Not a String.
+      break;
+
+    case JVM_CONSTANT_Class:
+    case JVM_CONSTANT_InterfaceMethodref:
+    case JVM_CONSTANT_Fieldref:
+    case JVM_CONSTANT_Methodref:
+    case JVM_CONSTANT_Integer:
+    case JVM_CONSTANT_Float:
+      // Do nothing!  Not an oop.
+      // These constant types do not reference symbols at this point.
+      break;
+
+    case JVM_CONSTANT_String:
+      closure->do_oop(obj_at_addr(index));
+      break;
+
+    case JVM_CONSTANT_UnresolvedString:
+    case JVM_CONSTANT_Utf8:
+      // These constants are symbols, but unless these symbols are
+      // actually to be used for something, we don't want to mark them.
+      break;
+
+    case JVM_CONSTANT_Long:
+    case JVM_CONSTANT_Double:
+      // Do nothing!  Not an oop. (But takes two pool entries.)
+      ++index;
+      break;
+
+    default:
+      ShouldNotReachHere();
+      break;
+    }
+  }
+}
+
+
+// Compare this constant pool's entry at index1 to the constant pool
+// cp2's entry at index2.
+bool constantPoolOopDesc::compare_entry_to(int index1, constantPoolHandle cp2,
+       int index2, TRAPS) {
+
+  jbyte t1 = tag_at(index1).value();
+  jbyte t2 = cp2->tag_at(index2).value();
+
+
+  // JVM_CONSTANT_UnresolvedClassInError is equal to JVM_CONSTANT_UnresolvedClass
+  // when comparing
+  if (t1 == JVM_CONSTANT_UnresolvedClassInError) {
+    t1 = JVM_CONSTANT_UnresolvedClass;
+  }
+  if (t2 == JVM_CONSTANT_UnresolvedClassInError) {
+    t2 = JVM_CONSTANT_UnresolvedClass;
+  }
+
+  if (t1 != t2) {
+    // Not the same entry type so there is nothing else to check. Note
+    // that this style of checking will consider resolved/unresolved
+    // class pairs and resolved/unresolved string pairs as different.
+    // From the constantPoolOop API point of view, this is correct
+    // behavior. See constantPoolKlass::merge() to see how this plays
+    // out in the context of constantPoolOop merging.
+    return false;
+  }
+
+  switch (t1) {
+  case JVM_CONSTANT_Class:
+  {
+    klassOop k1 = klass_at(index1, CHECK_false);
+    klassOop k2 = cp2->klass_at(index2, CHECK_false);
+    if (k1 == k2) {
+      return true;
+    }
+  } break;
+
+  case JVM_CONSTANT_ClassIndex:
+  {
+    int recur1 = klass_index_at(index1);
+    int recur2 = cp2->klass_index_at(index2);
+    bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
+    if (match) {
+      return true;
+    }
+  } break;
+
+  case JVM_CONSTANT_Double:
+  {
+    jdouble d1 = double_at(index1);
+    jdouble d2 = cp2->double_at(index2);
+    if (d1 == d2) {
+      return true;
+    }
+  } break;
+
+  case JVM_CONSTANT_Fieldref:
+  case JVM_CONSTANT_InterfaceMethodref:
+  case JVM_CONSTANT_Methodref:
+  {
+    int recur1 = uncached_klass_ref_index_at(index1);
+    int recur2 = cp2->uncached_klass_ref_index_at(index2);
+    bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
+    if (match) {
+      recur1 = uncached_name_and_type_ref_index_at(index1);
+      recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
+      match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
+      if (match) {
+        return true;
+      }
+    }
+  } break;
+
+  case JVM_CONSTANT_Float:
+  {
+    jfloat f1 = float_at(index1);
+    jfloat f2 = cp2->float_at(index2);
+    if (f1 == f2) {
+      return true;
+    }
+  } break;
+
+  case JVM_CONSTANT_Integer:
+  {
+    jint i1 = int_at(index1);
+    jint i2 = cp2->int_at(index2);
+    if (i1 == i2) {
+      return true;
+    }
+  } break;
+
+  case JVM_CONSTANT_Long:
+  {
+    jlong l1 = long_at(index1);
+    jlong l2 = cp2->long_at(index2);
+    if (l1 == l2) {
+      return true;
+    }
+  } break;
+
+  case JVM_CONSTANT_NameAndType:
+  {
+    int recur1 = name_ref_index_at(index1);
+    int recur2 = cp2->name_ref_index_at(index2);
+    bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
+    if (match) {
+      recur1 = signature_ref_index_at(index1);
+      recur2 = cp2->signature_ref_index_at(index2);
+      match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
+      if (match) {
+        return true;
+      }
+    }
+  } break;
+
+  case JVM_CONSTANT_String:
+  {
+    oop s1 = string_at(index1, CHECK_false);
+    oop s2 = cp2->string_at(index2, CHECK_false);
+    if (s1 == s2) {
+      return true;
+    }
+  } break;
+
+  case JVM_CONSTANT_StringIndex:
+  {
+    int recur1 = string_index_at(index1);
+    int recur2 = cp2->string_index_at(index2);
+    bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
+    if (match) {
+      return true;
+    }
+  } break;
+
+  case JVM_CONSTANT_UnresolvedClass:
+  {
+    symbolOop k1 = unresolved_klass_at(index1);
+    symbolOop k2 = cp2->unresolved_klass_at(index2);
+    if (k1 == k2) {
+      return true;
+    }
+  } break;
+
+  case JVM_CONSTANT_UnresolvedString:
+  {
+    symbolOop s1 = unresolved_string_at(index1);
+    symbolOop s2 = cp2->unresolved_string_at(index2);
+    if (s1 == s2) {
+      return true;
+    }
+  } break;
+
+  case JVM_CONSTANT_Utf8:
+  {
+    symbolOop s1 = symbol_at(index1);
+    symbolOop s2 = cp2->symbol_at(index2);
+    if (s1 == s2) {
+      return true;
+    }
+  } break;
+
+  // Invalid is used as the tag for the second constant pool entry
+  // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
+  // not be seen by itself.
+  case JVM_CONSTANT_Invalid: // fall through
+
+  default:
+    ShouldNotReachHere();
+    break;
+  }
+
+  return false;
+} // end compare_entry_to()
+
+
+// Copy this constant pool's entries at start_i to end_i (inclusive)
+// to the constant pool to_cp's entries starting at to_i. A total of
+// (end_i - start_i) + 1 entries are copied.
+void constantPoolOopDesc::copy_cp_to(int start_i, int end_i,
+       constantPoolHandle to_cp, int to_i, TRAPS) {
+
+  int dest_i = to_i;  // leave original alone for debug purposes
+
+  for (int src_i = start_i; src_i <= end_i; /* see loop bottom */ ) {
+    copy_entry_to(src_i, to_cp, dest_i, CHECK);
+
+    switch (tag_at(src_i).value()) {
+    case JVM_CONSTANT_Double:
+    case JVM_CONSTANT_Long:
+      // double and long take two constant pool entries
+      src_i += 2;
+      dest_i += 2;
+      break;
+
+    default:
+      // all others take one constant pool entry
+      src_i++;
+      dest_i++;
+      break;
+    }
+  }
+} // end copy_cp_to()
+
+
+// Copy this constant pool's entry at from_i to the constant pool
+// to_cp's entry at to_i.
+void constantPoolOopDesc::copy_entry_to(int from_i, constantPoolHandle to_cp,
+       int to_i, TRAPS) {
+
+  switch (tag_at(from_i).value()) {
+  case JVM_CONSTANT_Class:
+  {
+    klassOop k = klass_at(from_i, CHECK);
+    to_cp->klass_at_put(to_i, k);
+  } break;
+
+  case JVM_CONSTANT_ClassIndex:
+  {
+    jint ki = klass_index_at(from_i);
+    to_cp->klass_index_at_put(to_i, ki);
+  } break;
+
+  case JVM_CONSTANT_Double:
+  {
+    jdouble d = double_at(from_i);
+    to_cp->double_at_put(to_i, d);
+    // double takes two constant pool entries so init second entry's tag
+    to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
+  } break;
+
+  case JVM_CONSTANT_Fieldref:
+  {
+    int class_index = uncached_klass_ref_index_at(from_i);
+    int name_and_type_index = uncached_name_and_type_ref_index_at(from_i);
+    to_cp->field_at_put(to_i, class_index, name_and_type_index);
+  } break;
+
+  case JVM_CONSTANT_Float:
+  {
+    jfloat f = float_at(from_i);
+    to_cp->float_at_put(to_i, f);
+  } break;
+
+  case JVM_CONSTANT_Integer:
+  {
+    jint i = int_at(from_i);
+    to_cp->int_at_put(to_i, i);
+  } break;
+
+  case JVM_CONSTANT_InterfaceMethodref:
+  {
+    int class_index = uncached_klass_ref_index_at(from_i);
+    int name_and_type_index = uncached_name_and_type_ref_index_at(from_i);
+    to_cp->interface_method_at_put(to_i, class_index, name_and_type_index);
+  } break;
+
+  case JVM_CONSTANT_Long:
+  {
+    jlong l = long_at(from_i);
+    to_cp->long_at_put(to_i, l);
+    // long takes two constant pool entries so init second entry's tag
+    to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
+  } break;
+
+  case JVM_CONSTANT_Methodref:
+  {
+    int class_index = uncached_klass_ref_index_at(from_i);
+    int name_and_type_index = uncached_name_and_type_ref_index_at(from_i);
+    to_cp->method_at_put(to_i, class_index, name_and_type_index);
+  } break;
+
+  case JVM_CONSTANT_NameAndType:
+  {
+    int name_ref_index = name_ref_index_at(from_i);
+    int signature_ref_index = signature_ref_index_at(from_i);
+    to_cp->name_and_type_at_put(to_i, name_ref_index, signature_ref_index);
+  } break;
+
+  case JVM_CONSTANT_String:
+  {
+    oop s = string_at(from_i, CHECK);
+    to_cp->string_at_put(to_i, s);
+  } break;
+
+  case JVM_CONSTANT_StringIndex:
+  {
+    jint si = string_index_at(from_i);
+    to_cp->string_index_at_put(to_i, si);
+  } break;
+
+  case JVM_CONSTANT_UnresolvedClass:
+  {
+    symbolOop k = unresolved_klass_at(from_i);
+    to_cp->unresolved_klass_at_put(to_i, k);
+  } break;
+
+  case JVM_CONSTANT_UnresolvedClassInError:
+  {
+    symbolOop k = unresolved_klass_at(from_i);
+    to_cp->unresolved_klass_at_put(to_i, k);
+    to_cp->tag_at_put(to_i, JVM_CONSTANT_UnresolvedClassInError);
+  } break;
+
+
+  case JVM_CONSTANT_UnresolvedString:
+  {
+    symbolOop s = unresolved_string_at(from_i);
+    to_cp->unresolved_string_at_put(to_i, s);
+  } break;
+
+  case JVM_CONSTANT_Utf8:
+  {
+    symbolOop s = symbol_at(from_i);
+    to_cp->symbol_at_put(to_i, s);
+  } break;
+
+  // Invalid is used as the tag for the second constant pool entry
+  // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
+  // not be seen by itself.
+  case JVM_CONSTANT_Invalid: // fall through
+
+  default:
+  {
+    jbyte bad_value = tag_at(from_i).value(); // leave a breadcrumb
+    ShouldNotReachHere();
+  } break;
+  }
+} // end copy_entry_to()
+
+
+// Search constant pool search_cp for an entry that matches this
+// constant pool's entry at pattern_i. Returns the index of a
+// matching entry or zero (0) if there is no matching entry.
+int constantPoolOopDesc::find_matching_entry(int pattern_i,
+      constantPoolHandle search_cp, TRAPS) {
+
+  // index zero (0) is not used
+  for (int i = 1; i < search_cp->length(); i++) {
+    bool found = compare_entry_to(pattern_i, search_cp, i, CHECK_0);
+    if (found) {
+      return i;
+    }
+  }
+
+  return 0;  // entry not found; return unused index zero (0)
+} // end find_matching_entry()
+
+
+#ifndef PRODUCT
+
+const char* constantPoolOopDesc::printable_name_at(int which) {
+
+  constantTag tag = tag_at(which);
+
+  if (tag.is_unresolved_string() || tag.is_string()) {
+    return string_at_noresolve(which);
+  } else if (tag.is_klass() || tag.is_unresolved_klass()) {
+    return klass_name_at(which)->as_C_string();
+  } else if (tag.is_symbol()) {
+    return symbol_at(which)->as_C_string();
+  }
+  return "";
+}
+
+#endif // PRODUCT
+
+
+// JVMTI GetConstantPool support
+
+// For temporary use until code is stable.
+#define DBG(code)
+
+static const char* WARN_MSG = "Must not be such entry!";
+
+static void print_cpool_bytes(jint cnt, u1 *bytes) {
+  jint size = 0;
+  u2   idx1, idx2;
+
+  for (jint idx = 1; idx < cnt; idx++) {
+    jint ent_size = 0;
+    u1   tag  = *bytes++;
+    size++;                       // count tag
+
+    printf("const #%03d, tag: %02d ", idx, tag);
+    switch(tag) {
+      case JVM_CONSTANT_Invalid: {
+        printf("Invalid");
+        break;
+      }
+      case JVM_CONSTANT_Unicode: {
+        printf("Unicode      %s", WARN_MSG);
+        break;
+      }
+      case JVM_CONSTANT_Utf8: {
+        u2 len = Bytes::get_Java_u2(bytes);
+        char str[128];
+        if (len > 127) {
+           len = 127;
+        }
+        strncpy(str, (char *) (bytes+2), len);
+        str[len] = '\0';
+        printf("Utf8          \"%s\"", str);
+        ent_size = 2 + len;
+        break;
+      }
+      case JVM_CONSTANT_Integer: {
+        u4 val = Bytes::get_Java_u4(bytes);
+        printf("int          %d", *(int *) &val);
+        ent_size = 4;
+        break;
+      }
+      case JVM_CONSTANT_Float: {
+        u4 val = Bytes::get_Java_u4(bytes);
+        printf("float        %5.3ff", *(float *) &val);
+        ent_size = 4;
+        break;
+      }
+      case JVM_CONSTANT_Long: {
+        u8 val = Bytes::get_Java_u8(bytes);
+        printf("long         %lldl", *(jlong *) &val);
+        ent_size = 8;
+        idx++; // Long takes two cpool slots
+        break;
+      }
+      case JVM_CONSTANT_Double: {
+        u8 val = Bytes::get_Java_u8(bytes);
+        printf("double       %5.3fd", *(jdouble *)&val);
+        ent_size = 8;
+        idx++; // Double takes two cpool slots
+        break;
+      }
+      case JVM_CONSTANT_Class: {
+        idx1 = Bytes::get_Java_u2(bytes);
+        printf("class        #%03d", idx1);
+        ent_size = 2;
+        break;
+      }
+      case JVM_CONSTANT_String: {
+        idx1 = Bytes::get_Java_u2(bytes);
+        printf("String       #%03d", idx1);
+        ent_size = 2;
+        break;
+      }
+      case JVM_CONSTANT_Fieldref: {
+        idx1 = Bytes::get_Java_u2(bytes);
+        idx2 = Bytes::get_Java_u2(bytes+2);
+        printf("Field        #%03d, #%03d", (int) idx1, (int) idx2);
+        ent_size = 4;
+        break;
+      }
+      case JVM_CONSTANT_Methodref: {
+        idx1 = Bytes::get_Java_u2(bytes);
+        idx2 = Bytes::get_Java_u2(bytes+2);
+        printf("Method       #%03d, #%03d", idx1, idx2);
+        ent_size = 4;
+        break;
+      }
+      case JVM_CONSTANT_InterfaceMethodref: {
+        idx1 = Bytes::get_Java_u2(bytes);
+        idx2 = Bytes::get_Java_u2(bytes+2);
+        printf("InterfMethod #%03d, #%03d", idx1, idx2);
+        ent_size = 4;
+        break;
+      }
+      case JVM_CONSTANT_NameAndType: {
+        idx1 = Bytes::get_Java_u2(bytes);
+        idx2 = Bytes::get_Java_u2(bytes+2);
+        printf("NameAndType  #%03d, #%03d", idx1, idx2);
+        ent_size = 4;
+        break;
+      }
+      case JVM_CONSTANT_ClassIndex: {
+        printf("ClassIndex  %s", WARN_MSG);
+        break;
+      }
+      case JVM_CONSTANT_UnresolvedClass: {
+        printf("UnresolvedClass: %s", WARN_MSG);
+        break;
+      }
+      case JVM_CONSTANT_UnresolvedClassInError: {
+        printf("UnresolvedClassInErr: %s", WARN_MSG);
+        break;
+      }
+      case JVM_CONSTANT_StringIndex: {
+        printf("StringIndex: %s", WARN_MSG);
+        break;
+      }
+      case JVM_CONSTANT_UnresolvedString: {
+        printf("UnresolvedString: %s", WARN_MSG);
+        break;
+      }
+    }
+    printf(";\n");
+    bytes += ent_size;
+    size  += ent_size;
+  }
+  printf("Cpool size: %d\n", size);
+  fflush(0);
+  return;
+} /* end print_cpool_bytes */
+
+
+// Returns size of constant pool entry.
+jint constantPoolOopDesc::cpool_entry_size(jint idx) {
+  switch(tag_at(idx).value()) {
+    case JVM_CONSTANT_Invalid:
+    case JVM_CONSTANT_Unicode:
+      return 1;
+
+    case JVM_CONSTANT_Utf8:
+      return 3 + symbol_at(idx)->utf8_length();
+
+    case JVM_CONSTANT_Class:
+    case JVM_CONSTANT_String:
+    case JVM_CONSTANT_ClassIndex:
+    case JVM_CONSTANT_UnresolvedClass:
+    case JVM_CONSTANT_UnresolvedClassInError:
+    case JVM_CONSTANT_StringIndex:
+    case JVM_CONSTANT_UnresolvedString:
+      return 3;
+
+    case JVM_CONSTANT_Integer:
+    case JVM_CONSTANT_Float:
+    case JVM_CONSTANT_Fieldref:
+    case JVM_CONSTANT_Methodref:
+    case JVM_CONSTANT_InterfaceMethodref:
+    case JVM_CONSTANT_NameAndType:
+      return 5;
+
+    case JVM_CONSTANT_Long:
+    case JVM_CONSTANT_Double:
+      return 9;
+  }
+  assert(false, "cpool_entry_size: Invalid constant pool entry tag");
+  return 1;
+} /* end cpool_entry_size */
+
+
+// SymbolHashMap is used to find a constant pool index from a string.
+// This function fills in SymbolHashMaps, one for utf8s and one for
+// class names, returns size of the cpool raw bytes.
+jint constantPoolOopDesc::hash_entries_to(SymbolHashMap *symmap,
+                                          SymbolHashMap *classmap) {
+  jint size = 0;
+
+  for (u2 idx = 1; idx < length(); idx++) {
+    u2 tag = tag_at(idx).value();
+    size += cpool_entry_size(idx);
+
+    switch(tag) {
+      case JVM_CONSTANT_Utf8: {
+        symbolOop sym = symbol_at(idx);
+        symmap->add_entry(sym, idx);
+        DBG(printf("adding symbol entry %s = %d\n", sym->as_utf8(), idx));
+        break;
+      }
+      case JVM_CONSTANT_Class:
+      case JVM_CONSTANT_UnresolvedClass:
+      case JVM_CONSTANT_UnresolvedClassInError: {
+        symbolOop sym = klass_name_at(idx);
+        classmap->add_entry(sym, idx);
+        DBG(printf("adding class entry %s = %d\n", sym->as_utf8(), idx));
+        break;
+      }
+      case JVM_CONSTANT_Long:
+      case JVM_CONSTANT_Double: {
+        idx++; // Both Long and Double take two cpool slots
+        break;
+      }
+    }
+  }
+  return size;
+} /* end hash_utf8_entries_to */
+
+
+// Copy cpool bytes.
+// Returns:
+//    0, in case of OutOfMemoryError
+//   -1, in case of internal error
+//  > 0, count of the raw cpool bytes that have been copied
+int constantPoolOopDesc::copy_cpool_bytes(int cpool_size,
+                                          SymbolHashMap* tbl,
+                                          unsigned char *bytes) {
+  u2   idx1, idx2;
+  jint size  = 0;
+  jint cnt   = length();
+  unsigned char *start_bytes = bytes;
+
+  for (jint idx = 1; idx < cnt; idx++) {
+    u1   tag      = tag_at(idx).value();
+    jint ent_size = cpool_entry_size(idx);
+
+    assert(size + ent_size <= cpool_size, "Size mismatch");
+
+    *bytes = tag;
+    DBG(printf("#%03hd tag=%03hd, ", idx, tag));
+    switch(tag) {
+      case JVM_CONSTANT_Invalid: {
+        DBG(printf("JVM_CONSTANT_Invalid"));
+        break;
+      }
+      case JVM_CONSTANT_Unicode: {
+        assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode");
+        DBG(printf("JVM_CONSTANT_Unicode"));
+        break;
+      }
+      case JVM_CONSTANT_Utf8: {
+        symbolOop sym = symbol_at(idx);
+        char*     str = sym->as_utf8();
+        // Warning! It's crashing on x86 with len = sym->utf8_length()
+        int       len = (int) strlen(str);
+        Bytes::put_Java_u2((address) (bytes+1), (u2) len);
+        for (int i = 0; i < len; i++) {
+            bytes[3+i] = (u1) str[i];
+        }
+        DBG(printf("JVM_CONSTANT_Utf8: %s ", str));
+        break;
+      }
+      case JVM_CONSTANT_Integer: {
+        jint val = int_at(idx);
+        Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
+        break;
+      }
+      case JVM_CONSTANT_Float: {
+        jfloat val = float_at(idx);
+        Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
+        break;
+      }
+      case JVM_CONSTANT_Long: {
+        jlong val = long_at(idx);
+        Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
+        idx++;             // Long takes two cpool slots
+        break;
+      }
+      case JVM_CONSTANT_Double: {
+        jdouble val = double_at(idx);
+        Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
+        idx++;             // Double takes two cpool slots
+        break;
+      }
+      case JVM_CONSTANT_Class:
+      case JVM_CONSTANT_UnresolvedClass:
+      case JVM_CONSTANT_UnresolvedClassInError: {
+        *bytes = JVM_CONSTANT_Class;
+        symbolOop sym = klass_name_at(idx);
+        idx1 = tbl->symbol_to_value(sym);
+        assert(idx1 != 0, "Have not found a hashtable entry");
+        Bytes::put_Java_u2((address) (bytes+1), idx1);
+        DBG(printf("JVM_CONSTANT_Class: idx=#%03hd, %s", idx1, sym->as_utf8()));
+        break;
+      }
+      case JVM_CONSTANT_String: {
+        unsigned int hash;
+        char *str = string_at_noresolve(idx);
+        symbolOop sym = SymbolTable::lookup_only(str, (int) strlen(str), hash);
+        idx1 = tbl->symbol_to_value(sym);
+        assert(idx1 != 0, "Have not found a hashtable entry");
+        Bytes::put_Java_u2((address) (bytes+1), idx1);
+        DBG(printf("JVM_CONSTANT_String: idx=#%03hd, %s", idx1, str));
+        break;
+      }
+      case JVM_CONSTANT_UnresolvedString: {
+        *bytes = JVM_CONSTANT_String;
+        symbolOop sym = unresolved_string_at(idx);
+        idx1 = tbl->symbol_to_value(sym);
+        assert(idx1 != 0, "Have not found a hashtable entry");
+        Bytes::put_Java_u2((address) (bytes+1), idx1);
+        DBG(char *str = sym->as_utf8());
+        DBG(printf("JVM_CONSTANT_UnresolvedString: idx=#%03hd, %s", idx1, str));
+        break;
+      }
+      case JVM_CONSTANT_Fieldref:
+      case JVM_CONSTANT_Methodref:
+      case JVM_CONSTANT_InterfaceMethodref: {
+        idx1 = uncached_klass_ref_index_at(idx);
+        idx2 = uncached_name_and_type_ref_index_at(idx);
+        Bytes::put_Java_u2((address) (bytes+1), idx1);
+        Bytes::put_Java_u2((address) (bytes+3), idx2);
+        DBG(printf("JVM_CONSTANT_Methodref: %hd %hd", idx1, idx2));
+        break;
+      }
+      case JVM_CONSTANT_NameAndType: {
+        idx1 = name_ref_index_at(idx);
+        idx2 = signature_ref_index_at(idx);
+        Bytes::put_Java_u2((address) (bytes+1), idx1);
+        Bytes::put_Java_u2((address) (bytes+3), idx2);
+        DBG(printf("JVM_CONSTANT_NameAndType: %hd %hd", idx1, idx2));
+        break;
+      }
+      case JVM_CONSTANT_ClassIndex: {
+        *bytes = JVM_CONSTANT_Class;
+        idx1 = klass_index_at(idx);
+        Bytes::put_Java_u2((address) (bytes+1), idx1);
+        DBG(printf("JVM_CONSTANT_ClassIndex: %hd", idx1));
+        break;
+      }
+      case JVM_CONSTANT_StringIndex: {
+        *bytes = JVM_CONSTANT_String;
+        idx1 = string_index_at(idx);
+        Bytes::put_Java_u2((address) (bytes+1), idx1);
+        DBG(printf("JVM_CONSTANT_StringIndex: %hd", idx1));
+        break;
+      }
+    }
+    DBG(printf("\n"));
+    bytes += ent_size;
+    size  += ent_size;
+  }
+  assert(size == cpool_size, "Size mismatch");
+
+  // Keep temorarily for debugging until it's stable.
+  DBG(print_cpool_bytes(cnt, start_bytes));
+  return (int)(bytes - start_bytes);
+} /* end copy_cpool_bytes */
+
+
+void SymbolHashMap::add_entry(symbolOop sym, u2 value) {
+  char *str = sym->as_utf8();
+  unsigned int hash = compute_hash(str, sym->utf8_length());
+  unsigned int index = hash % table_size();
+
+  // check if already in map
+  // we prefer the first entry since it is more likely to be what was used in
+  // the class file
+  for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
+    assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
+    if (en->hash() == hash && en->symbol() == sym) {
+        return;  // already there
+    }
+  }
+
+  SymbolHashMapEntry* entry = new SymbolHashMapEntry(hash, sym, value);
+  entry->set_next(bucket(index));
+  _buckets[index].set_entry(entry);
+  assert(entry->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
+}
+
+SymbolHashMapEntry* SymbolHashMap::find_entry(symbolOop sym) {
+  assert(sym != NULL, "SymbolHashMap::find_entry - symbol is NULL");
+  char *str = sym->as_utf8();
+  int   len = sym->utf8_length();
+  unsigned int hash = SymbolHashMap::compute_hash(str, len);
+  unsigned int index = hash % table_size();
+  for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
+    assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
+    if (en->hash() == hash && en->symbol() == sym) {
+      return en;
+    }
+  }
+  return NULL;
+}