1 /*
   2  * Copyright (c) 2000, 2010, 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/ciObject.hpp"
  29 #include "oops/klassOop.hpp"
  30 
  31 // ciType
  32 //
  33 // This class represents either a class (T_OBJECT), array (T_ARRAY),
  34 // or one of the primitive types such as T_INT.
  35 class ciType : public ciObject {
  36   CI_PACKAGE_ACCESS
  37   friend class ciKlass;
  38   friend class ciReturnAddress;
  39 
  40 private:
  41   BasicType _basic_type;
  42 
  43   ciType(BasicType t);     // for the primitive types only
  44   ciType(KlassHandle k);   // for subclasses (reference types)
  45   ciType(ciKlass* klass);  // for unloaded types
  46 
  47   const char* type_string() { return "ciType"; }
  48 
  49   void print_impl(outputStream* st);
  50 
  51   // Distinguished instances of primitive ciTypes..
  52   static ciType* _basic_types[T_CONFLICT+1];
  53 
  54 public:
  55   BasicType basic_type() const              { return _basic_type; }
  56 
  57   // Returns true iff the types are identical, or if both are klasses
  58   // and the is_subtype_of relation holds between the klasses.
  59   bool is_subtype_of(ciType* type);
  60 
  61   // Get the instance of java.lang.Class corresponding to this type.
  62   // There are mirrors for instance, array, and primitive types (incl. void).
  63   virtual ciInstance*    java_mirror();
  64 
  65   // Get the class which "boxes" (or "wraps") values of this type.
  66   // Example:  short is boxed by java.lang.Short, etc.
  67   // Returns self if it is a reference type.
  68   // Returns NULL for void, since null is used in such cases.
  69   ciKlass*  box_klass();
  70 
  71   // Returns true if this is not a klass or array (i.e., not a reference type).
  72   bool is_primitive_type() const            { return basic_type() != T_OBJECT && basic_type() != T_ARRAY; }
  73   int size() const                          { return type2size[basic_type()]; }
  74   bool is_void() const                      { return basic_type() == T_VOID; }
  75   bool is_one_word() const                  { return size() == 1; }
  76   bool is_two_word() const                  { return size() == 2; }
  77 
  78   // What kind of ciObject is this?
  79   bool is_type()                            { return true; }
  80   bool is_classless() const                 { return is_primitive_type(); }
  81 
  82   virtual void print_name_on(outputStream* st);
  83   void print_name() {
  84     print_name_on(tty);
  85   }
  86 
  87   static ciType* make(BasicType t);
  88 };
  89 
  90 
  91 // ciReturnAddress
  92 //
  93 // This class represents the type of a specific return address in the
  94 // bytecodes.
  95 class ciReturnAddress : public ciType {
  96   CI_PACKAGE_ACCESS
  97 
  98 private:
  99   // The bci of this return address.
 100   int _bci;
 101 
 102   ciReturnAddress(int bci);
 103 
 104   const char* type_string() { return "ciReturnAddress"; }
 105 
 106   void print_impl(outputStream* st);
 107 
 108 public:
 109   bool is_return_address()  { return true; }
 110 
 111   int  bci() { return _bci; }
 112 
 113   static ciReturnAddress* make(int bci);
 114 };
 115 
 116 #endif // SHARE_VM_CI_CITYPE_HPP