xref: /openjdk10/hotspot/src/share/vm/utilities/constantTag.hpp

/*
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 * 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
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// 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_UnresolvedString         = 102,  // Temporary tag until actual use
  JVM_CONSTANT_StringIndex              = 103,  // Temporary tag while constructing constant pool
  JVM_CONSTANT_UnresolvedClassInError   = 104,  // Error tag due to resolution error
  JVM_CONSTANT_Object                   = 105,  // Required for BoundMethodHandle arguments.
  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_klass_index() const       { return _tag == JVM_CONSTANT_ClassIndex; }
  bool is_unresolved_string() const { return _tag == JVM_CONSTANT_UnresolvedString; }
  bool is_string_index() const      { return _tag == JVM_CONSTANT_StringIndex; }

  bool is_object() const            { return _tag == JVM_CONSTANT_Object; }

  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; }

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

  jbyte value()                      { return _tag; }

  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;
};