1 /*
   2  * Copyright (c) 2000, 2017, 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_VM_CI_CITYPE_HPP
  26 #define SHARE_VM_CI_CITYPE_HPP
  27 
  28 #include "ci/ciMetadata.hpp"
  29 
  30 // ciType
  31 //
  32 // This class represents either a class (T_OBJECT), value (T_VALUETYPE),
  33 // array (T_ARRAY), or one of the primitive types such as T_INT.
  34 class ciType : public ciMetadata {
  35   CI_PACKAGE_ACCESS
  36   friend class ciKlass;
  37   friend class ciReturnAddress;
  38 
  39 private:
  40   BasicType _basic_type;
  41 
  42   ciType(BasicType t);     // for primitive and unloaded types
  43   ciType(Klass* k);        // for subclasses (reference types)
  44 
  45   const char* type_string() { return "ciType"; }
  46 
  47   void print_impl(outputStream* st);
  48 
  49   // Distinguished instances of primitive ciTypes..
  50   static ciType* _basic_types[T_CONFLICT+1];
  51 
  52 public:
  53   BasicType basic_type() const              { return _basic_type; }
  54 
  55   // Returns true iff the types are identical, or if both are klasses
  56   // and the is_subtype_of relation holds between the klasses.
  57   bool is_subtype_of(ciType* type);
  58 
  59   // Get the instance of java.lang.Class corresponding to this type.
  60   // There are mirrors for instance, array, and primitive types (incl. void).
  61   virtual ciInstance*    java_mirror();
  62 
  63   // Get the class which "boxes" (or "wraps") values of this type.
  64   // Example:  short is boxed by java.lang.Short, etc.
  65   // Returns self if it is a reference type.
  66   // Returns NULL for void, since null is used in such cases.
  67   ciKlass*  box_klass();
  68 
  69   // Returns true if this is not a klass or array (i.e., not a reference type).
  70   bool is_primitive_type() const            { return basic_type() != T_OBJECT && basic_type() != T_ARRAY && basic_type() != T_VALUETYPE; }
  71   int size() const                          { return type2size[basic_type()]; }
  72   bool is_void() const                      { return basic_type() == T_VOID; }
  73   bool is_one_word() const                  { return size() == 1; }
  74   bool is_two_word() const                  { return size() == 2; }
  75 
  76   // What kind of ciObject is this?
  77   bool is_type() const                      { return true; }
  78   bool is_classless() const                 { return is_primitive_type(); }
  79 
  80   const char* name();
  81   virtual void print_name_on(outputStream* st);
  82   void print_name() {
  83     print_name_on(tty);
  84   }
  85 
  86   static ciType* make(BasicType t);
  87 };
  88 
  89 
  90 // ciReturnAddress
  91 //
  92 // This class represents the type of a specific return address in the
  93 // bytecodes.
  94 class ciReturnAddress : public ciType {
  95   CI_PACKAGE_ACCESS
  96 
  97 private:
  98   // The bci of this return address.
  99   int _bci;
 100 
 101   ciReturnAddress(int bci);
 102 
 103   const char* type_string() { return "ciReturnAddress"; }
 104 
 105   void print_impl(outputStream* st);
 106 
 107 public:
 108   bool is_return_address() const { return true; }
 109 
 110   int  bci() { return _bci; }
 111 
 112   static ciReturnAddress* make(int bci);
 113 };
 114 
 115 #endif // SHARE_VM_CI_CITYPE_HPP