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 
 75   virtual ciType* unwrap()                  { return this; }
 76   virtual bool is_null_free() const         { return false; }
 77 
 78   const char* name();
 79   virtual void print_name_on(outputStream* st);
 80   void print_name() {
 81     print_name_on(tty);
 82   }
 83 
 84   static ciType* make(BasicType t);
 85 };
 86 
 87 
 88 // ciReturnAddress
 89 //
 90 // This class represents the type of a specific return address in the
 91 // bytecodes.
 92 class ciReturnAddress : public ciType {
 93   CI_PACKAGE_ACCESS
 94 
 95 private:
 96   // The bci of this return address.
 97   int _bci;
 98 
 99   ciReturnAddress(int bci);
100 
101   const char* type_string() { return "ciReturnAddress"; }
102 
103   void print_impl(outputStream* st);
104 
105 public:
106   bool is_return_address() const { return true; }
107 
108   int  bci() { return _bci; }
109 
110   static ciReturnAddress* make(int bci);
111 };
112 
113 // ciWrapper
114 //
115 // This class wraps another type to carry additional information.
116 // Currently it is only used to mark inline klasses as null-free.
117 class ciWrapper : public ciType {
118   CI_PACKAGE_ACCESS
119 
120 private:
121   ciType* _type;
122 
123   ciWrapper(ciType* type) : ciType(type->basic_type()) {
124     assert(type->is_inlinetype()
125           // An unloaded inline type is an instance_klass (see ciEnv::get_klass_by_name_impl())
126           || (type->is_instance_klass() && !type->is_loaded()),
127           "should only be used for inline types");
128     _type = type;
129   }
130 
131   const char* type_string() { return "ciWrapper"; }
132 
133   void print_impl(outputStream* st) { _type->print_impl(st); }
134 
135 public:
136   bool is_wrapper()   const { return true; }
137   ciType* unwrap()          { return _type; }
138   bool is_null_free() const { return true; }
139 };
140 
141 #endif // SHARE_CI_CITYPE_HPP