Java example source code file (constantTag.hpp)

This example Java source code file (constantTag.hpp) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

error, jvm_constant_classindex, jvm_constant_internalmax, jvm_constant_internalmin, jvm_constant_invalid, jvm_constant_invokedynamic, jvm_constant_methodhandle, jvm_constant_methodhandleinerror, jvm_constant_methodtypeinerror, jvm_constant_nameandtype, jvm_constant_string, jvm_constant_unresolvedclassinerror, share_vm_utilities_constanttag_hpp, temporary

The constantTag.hpp Java example source code

/*
 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#ifndef SHARE_VM_UTILITIES_CONSTANTTAG_HPP
#define SHARE_VM_UTILITIES_CONSTANTTAG_HPP

#include "prims/jvm.h"
#include "utilities/top.hpp"

// constant tags in Java .class files


enum {
  // See jvm.h for shared JVM_CONSTANT_XXX tags
  // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/utilities/ConstantTag.java
  // Hotspot specific tags
  JVM_CONSTANT_Invalid                  = 0,    // For bad value initialization
  JVM_CONSTANT_InternalMin              = 100,  // First implementation tag (aside from bad value of course)
  JVM_CONSTANT_UnresolvedClass          = 100,  // Temporary tag until actual use
  JVM_CONSTANT_ClassIndex               = 101,  // Temporary tag while constructing constant pool
  JVM_CONSTANT_StringIndex              = 102,  // Temporary tag while constructing constant pool
  JVM_CONSTANT_UnresolvedClassInError   = 103,  // Error tag due to resolution error
  JVM_CONSTANT_MethodHandleInError      = 104,  // Error tag due to resolution error
  JVM_CONSTANT_MethodTypeInError        = 105,  // Error tag due to resolution error
  JVM_CONSTANT_InternalMax              = 105   // Last implementation tag
};


class constantTag VALUE_OBJ_CLASS_SPEC {
 private:
  jbyte _tag;
 public:
  bool is_klass() const             { return _tag == JVM_CONSTANT_Class; }
  bool is_field () const            { return _tag == JVM_CONSTANT_Fieldref; }
  bool is_method() const            { return _tag == JVM_CONSTANT_Methodref; }
  bool is_interface_method() const  { return _tag == JVM_CONSTANT_InterfaceMethodref; }
  bool is_string() const            { return _tag == JVM_CONSTANT_String; }
  bool is_int() const               { return _tag == JVM_CONSTANT_Integer; }
  bool is_float() const             { return _tag == JVM_CONSTANT_Float; }
  bool is_long() const              { return _tag == JVM_CONSTANT_Long; }
  bool is_double() const            { return _tag == JVM_CONSTANT_Double; }
  bool is_name_and_type() const     { return _tag == JVM_CONSTANT_NameAndType; }
  bool is_utf8() const              { return _tag == JVM_CONSTANT_Utf8; }

  bool is_invalid() const           { return _tag == JVM_CONSTANT_Invalid; }

  bool is_unresolved_klass() const {
    return _tag == JVM_CONSTANT_UnresolvedClass || _tag == JVM_CONSTANT_UnresolvedClassInError;
  }

  bool is_unresolved_klass_in_error() const {
    return _tag == JVM_CONSTANT_UnresolvedClassInError;
  }

  bool is_method_handle_in_error() const {
    return _tag == JVM_CONSTANT_MethodHandleInError;
  }
  bool is_method_type_in_error() const {
    return _tag == JVM_CONSTANT_MethodTypeInError;
  }

  bool is_klass_index() const       { return _tag == JVM_CONSTANT_ClassIndex; }
  bool is_string_index() const      { return _tag == JVM_CONSTANT_StringIndex; }

  bool is_klass_reference() const   { return is_klass_index() || is_unresolved_klass(); }
  bool is_klass_or_reference() const{ return is_klass() || is_klass_reference(); }
  bool is_field_or_method() const   { return is_field() || is_method() || is_interface_method(); }
  bool is_symbol() const            { return is_utf8(); }

  bool is_method_type() const              { return _tag == JVM_CONSTANT_MethodType; }
  bool is_method_handle() const            { return _tag == JVM_CONSTANT_MethodHandle; }
  bool is_invoke_dynamic() const           { return _tag == JVM_CONSTANT_InvokeDynamic; }

  bool is_loadable_constant() const {
    return ((_tag >= JVM_CONSTANT_Integer && _tag <= JVM_CONSTANT_String) ||
            is_method_type() || is_method_handle() ||
            is_unresolved_klass());
  }

  constantTag() {
    _tag = JVM_CONSTANT_Invalid;
  }
  constantTag(jbyte tag) {
    assert((tag >= 0 && tag <= JVM_CONSTANT_NameAndType) ||
           (tag >= JVM_CONSTANT_MethodHandle && tag <= JVM_CONSTANT_InvokeDynamic) ||
           (tag >= JVM_CONSTANT_InternalMin && tag <= JVM_CONSTANT_InternalMax), "Invalid constant tag");
    _tag = tag;
  }

  jbyte value() const                { return _tag; }
  jbyte non_error_value() const;

  BasicType basic_type() const;        // if used with ldc, what kind of value gets pushed?

  const char* internal_name() const;  // for error reporting

  void print_on(outputStream* st) const PRODUCT_RETURN;
};

#endif // SHARE_VM_UTILITIES_CONSTANTTAG_HPP