1 /*
   2  * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_UTILITIES_CONSTANTTAG_HPP
  26 #define SHARE_UTILITIES_CONSTANTTAG_HPP
  27 
  28 #include "jvm.h"
  29 #include "utilities/globalDefinitions.hpp"
  30 
  31 
  32 class outputStream;
  33 
  34 // constant tags in Java .class files
  35 
  36 enum {
  37   // See jvm.h for shared JVM_CONSTANT_XXX tags
  38   // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/utilities/ConstantTag.java
  39   // Hotspot specific tags
  40   JVM_CONSTANT_Invalid                  = 0,    // For bad value initialization
  41   JVM_CONSTANT_InternalMin              = 100,  // First implementation tag (aside from bad value of course)
  42   JVM_CONSTANT_UnresolvedClass          = 100,  // Temporary tag until actual use
  43   JVM_CONSTANT_ClassIndex               = 101,  // Temporary tag while constructing constant pool, class redefinition
  44   JVM_CONSTANT_StringIndex              = 102,  // Temporary tag while constructing constant pool, class redefinition
  45   JVM_CONSTANT_UnresolvedClassInError   = 103,  // Error tag due to resolution error
  46   JVM_CONSTANT_MethodHandleInError      = 104,  // Error tag due to resolution error
  47   JVM_CONSTANT_MethodTypeInError        = 105,  // Error tag due to resolution error
  48   JVM_CONSTANT_DynamicInError           = 106,  // Error tag due to resolution error
  49   JVM_CONSTANT_InternalMax              = 106,  // Last implementation tag
  50   // internal constant tag flags
  51   JVM_CONSTANT_QDescBit                 = (1 << 7) // Separate bit, encode Q type descriptors
  52 };
  53 
  54 class constantTag {
  55  private:
  56   jbyte _tag;
  57  public:
  58   bool is_klass() const             { return value() == JVM_CONSTANT_Class; }
  59   bool is_field () const            { return _tag == JVM_CONSTANT_Fieldref; }
  60   bool is_method() const            { return _tag == JVM_CONSTANT_Methodref; }
  61   bool is_interface_method() const  { return _tag == JVM_CONSTANT_InterfaceMethodref; }
  62   bool is_string() const            { return _tag == JVM_CONSTANT_String; }
  63   bool is_int() const               { return _tag == JVM_CONSTANT_Integer; }
  64   bool is_float() const             { return _tag == JVM_CONSTANT_Float; }
  65   bool is_long() const              { return _tag == JVM_CONSTANT_Long; }
  66   bool is_double() const            { return _tag == JVM_CONSTANT_Double; }
  67   bool is_name_and_type() const     { return _tag == JVM_CONSTANT_NameAndType; }
  68   bool is_utf8() const              { return _tag == JVM_CONSTANT_Utf8; }
  69 
  70   bool is_invalid() const           { return _tag == JVM_CONSTANT_Invalid; }
  71 
  72   bool is_unresolved_klass() const {
  73     return value() == JVM_CONSTANT_UnresolvedClass || value() == JVM_CONSTANT_UnresolvedClassInError;
  74   }
  75 
  76   bool is_unresolved_klass_in_error() const {
  77     return value() == JVM_CONSTANT_UnresolvedClassInError;
  78   }
  79 
  80   bool is_Qdescriptor_klass() const {
  81     return (_tag & JVM_CONSTANT_QDescBit) != 0;
  82   }
  83 
  84   bool is_method_handle_in_error() const {
  85     return _tag == JVM_CONSTANT_MethodHandleInError;
  86   }
  87   bool is_method_type_in_error() const {
  88     return _tag == JVM_CONSTANT_MethodTypeInError;
  89   }
  90 
  91   bool is_dynamic_constant_in_error() const {
  92     return _tag == JVM_CONSTANT_DynamicInError;
  93   }
  94 
  95   bool is_klass_index() const       { return _tag == JVM_CONSTANT_ClassIndex; }
  96   bool is_string_index() const      { return _tag == JVM_CONSTANT_StringIndex; }
  97 
  98   bool is_klass_reference() const   { return is_klass_index() || is_unresolved_klass(); }
  99   bool is_klass_or_reference() const{ return is_klass() || is_klass_reference(); }
 100   bool is_field_or_method() const   { return is_field() || is_method() || is_interface_method(); }
 101   bool is_symbol() const            { return is_utf8(); }
 102 
 103   bool is_method_type() const       { return _tag == JVM_CONSTANT_MethodType; }
 104   bool is_method_handle() const     { return _tag == JVM_CONSTANT_MethodHandle; }
 105   bool is_dynamic_constant() const  { return _tag == JVM_CONSTANT_Dynamic; }
 106   bool is_invoke_dynamic() const    { return _tag == JVM_CONSTANT_InvokeDynamic; }
 107 
 108   bool has_bootstrap() const {
 109     return (_tag == JVM_CONSTANT_Dynamic ||
 110             _tag == JVM_CONSTANT_DynamicInError ||
 111             _tag == JVM_CONSTANT_InvokeDynamic);
 112   }
 113 
 114   bool is_loadable_constant() const {
 115     return ((_tag >= JVM_CONSTANT_Integer && _tag <= JVM_CONSTANT_String) ||
 116             is_method_type() || is_method_handle() || is_dynamic_constant() ||
 117             is_unresolved_klass());
 118   }
 119 
 120   constantTag() {
 121     _tag = JVM_CONSTANT_Invalid;
 122   }
 123   constantTag(jbyte tag) {
 124     jbyte entry_tag = tag & ~JVM_CONSTANT_QDescBit;
 125     assert((((tag & JVM_CONSTANT_QDescBit) == 0) && (entry_tag >= 0 && entry_tag <= JVM_CONSTANT_NameAndType) ||
 126            (entry_tag >= JVM_CONSTANT_MethodHandle && entry_tag <= JVM_CONSTANT_InvokeDynamic) ||
 127            (entry_tag >= JVM_CONSTANT_InternalMin && entry_tag <= JVM_CONSTANT_InternalMax))
 128            || (((tag & JVM_CONSTANT_QDescBit) != 0) && (entry_tag == JVM_CONSTANT_Class ||
 129                entry_tag == JVM_CONSTANT_UnresolvedClass || entry_tag == JVM_CONSTANT_UnresolvedClassInError
 130                || entry_tag == JVM_CONSTANT_ClassIndex))
 131                , "Invalid constant tag");
 132     _tag = tag;
 133   }
 134 
 135   static constantTag ofBasicType(BasicType bt) {
 136     if (is_subword_type(bt))  bt = T_INT;
 137     switch (bt) {
 138       case T_OBJECT: return constantTag(JVM_CONSTANT_String);
 139       case T_INT:    return constantTag(JVM_CONSTANT_Integer);
 140       case T_LONG:   return constantTag(JVM_CONSTANT_Long);
 141       case T_FLOAT:  return constantTag(JVM_CONSTANT_Float);
 142       case T_DOUBLE: return constantTag(JVM_CONSTANT_Double);
 143       default:       break;
 144     }
 145     assert(false, "bad basic type for tag");
 146     return constantTag();
 147   }
 148 
 149   jbyte value() const                { return _tag & ~JVM_CONSTANT_QDescBit; }
 150   jbyte tag() const                  { return _tag; }
 151   jbyte error_value() const;
 152   jbyte non_error_value() const;
 153 
 154   BasicType basic_type() const;        // if used with ldc, what kind of value gets pushed?
 155 
 156   const char* internal_name() const;  // for error reporting
 157 
 158   void print_on(outputStream* st) const PRODUCT_RETURN;
 159 };
 160 
 161 #endif // SHARE_UTILITIES_CONSTANTTAG_HPP