1 /*
  2  * Copyright (c) 2000, 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_CI_CITYPE_HPP
 26 #define SHARE_CI_CITYPE_HPP
 27 
 28 #include "ci/ciMetadata.hpp"
 29 
 30 // ciType
 31 //
 32 // This class represents a Java reference, inline type or primitive type.
 33 
 34 class ciType : public ciMetadata {
 35   CI_PACKAGE_ACCESS
 36   friend class ciKlass;
 37   friend class ciReturnAddress;
 38   friend class ciWrapper;
 39 
 40 private:
 41   BasicType _basic_type;
 42 
 43   ciType(BasicType t);     // for primitive and unloaded types
 44   ciType(Klass* k);        // for subclasses (reference types)
 45 
 46   const char* type_string() { return "ciType"; }
 47 
 48   void print_impl(outputStream* st);
 49 
 50   // Distinguished instances of primitive ciTypes..
 51   static ciType* _basic_types[T_CONFLICT+1];
 52 
 53 public:
 54   BasicType basic_type() const              { return _basic_type; }
 55 
 56   // Returns true iff the types are identical, or if both are klasses
 57   // and the is_subtype_of relation holds between the klasses.
 58   bool is_subtype_of(ciType* type);
 59 
 60   // Get the instance of java.lang.Class corresponding to this type.
 61   // There are mirrors for instance, array, and primitive types (incl. void).
 62   virtual ciInstance*    java_mirror();
 63 
 64   // Returns true if this is not a klass or array (i.e., not a reference type).
 65   bool is_primitive_type() const            { return !is_reference_type(basic_type()); }
 66   int size() const                          { return type2size[basic_type()]; }
 67   bool is_void() const                      { return basic_type() == T_VOID; }
 68   bool is_one_word() const                  { return size() == 1; }
 69   bool is_two_word() const                  { return size() == 2; }
 70 
 71   // What kind of ciObject is this?
 72   bool is_type() const                      { return true; }
 73   bool is_classless() const                 { return is_primitive_type(); }
 74   virtual bool is_wrapper() const           { return false; }
 75 
 76   virtual ciType* unwrap()                  { return this; }
 77   virtual bool is_null_free() const         { return false; }
 78 
 79   const char* name();
 80   virtual void print_name_on(outputStream* st);
 81   void print_name() {
 82     print_name_on(tty);
 83   }
 84 
 85   static ciType* make(BasicType t);
 86 };
 87 
 88 
 89 // ciReturnAddress
 90 //
 91 // This class represents the type of a specific return address in the
 92 // bytecodes.
 93 class ciReturnAddress : public ciType {
 94   CI_PACKAGE_ACCESS
 95 
 96 private:
 97   // The bci of this return address.
 98   int _bci;
 99 
100   ciReturnAddress(int bci);
101 
102   const char* type_string() { return "ciReturnAddress"; }
103 
104   void print_impl(outputStream* st);
105 
106 public:
107   bool is_return_address() const { return true; }
108 
109   int  bci() { return _bci; }
110 
111   static ciReturnAddress* make(int bci);
112 };
113 
114 // ciWrapper
115 //
116 // This class wraps another type to carry additional information.
117 class ciWrapper : public ciType {
118   CI_PACKAGE_ACCESS
119 
120 private:
121   ciType* _type;
122   enum Property {
123     NullFree = 1,
124     EarlyLarval = NullFree << 1,
125   };
126   int _properties;
127 
128   ciWrapper(ciType* type, int properties);
129 
130   const char* type_string() override { return "ciWrapper"; }
131 
132   void print_impl(outputStream* st) override { _type->print_impl(st); }
133 
134 public:
135   ciType* unwrap() override { return _type; }
136   bool is_null_free() const override { return (_properties & (NullFree | EarlyLarval)) != 0; }
137   bool is_early_larval() const override { return (_properties & EarlyLarval) != 0; }
138   bool is_wrapper() const override { return true; }
139 };
140 
141 #endif // SHARE_CI_CITYPE_HPP