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 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 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 // Get the class which "boxes" (or "wraps") values of this type.
65 // Example: short is boxed by java.lang.Short, etc.
66 // Returns self if it is a reference type.
67 // Returns NULL for void, since null is used in such cases.
68 ciKlass* box_klass();
69
70 // Returns true if this is not a klass or array (i.e., not a reference type).
71 bool is_primitive_type() const { return basic_type() != T_OBJECT && basic_type() != T_ARRAY && basic_type() != T_VALUETYPE; }
72 int size() const { return type2size[basic_type()]; }
73 bool is_void() const { return basic_type() == T_VOID; }
74 bool is_one_word() const { return size() == 1; }
75 bool is_two_word() const { return size() == 2; }
76
77 // What kind of ciObject is this?
78 bool is_type() const { return true; }
79 bool is_classless() const { return is_primitive_type(); }
80
81 virtual ciType* unwrap() { return this; }
82 virtual bool is_never_null() const { return false; }
83
84 const char* name();
85 virtual void print_name_on(outputStream* st);
86 void print_name() {
87 print_name_on(tty);
88 }
89
90 static ciType* make(BasicType t);
91 };
92
93
94 // ciReturnAddress
95 //
96 // This class represents the type of a specific return address in the
97 // bytecodes.
98 class ciReturnAddress : public ciType {
99 CI_PACKAGE_ACCESS
100
101 private:
102 // The bci of this return address.
103 int _bci;
104
105 ciReturnAddress(int bci);
106
107 const char* type_string() { return "ciReturnAddress"; }
108
109 void print_impl(outputStream* st);
110
111 public:
112 bool is_return_address() const { return true; }
113
114 int bci() { return _bci; }
115
116 static ciReturnAddress* make(int bci);
117 };
118
119 // ciWrapper
120 //
121 // This class wraps another type to carry additional information like nullability.
122 // Should only be instantiated and used by ciTypeFlow and ciSignature.
123 class ciWrapper : public ciType {
124 CI_PACKAGE_ACCESS
125
126 private:
127 ciType* _type;
128 bool _never_null;
129
130 ciWrapper(ciType* type, bool never_null) : ciType(type->basic_type()) {
131 assert(type->is_valuetype(), "should only be used for value types");
132 _type = type;
133 _never_null = never_null;
134 }
135
136 const char* type_string() { return "ciWrapper"; }
137
138 void print_impl(outputStream* st) { _type->print_impl(st); }
139
140 public:
141 bool equals(ciMetadata* obj) const {
142 return obj->is_wrapper() &&
143 obj->as_wrapper()->unwrap()->equals(_type) &&
144 obj->as_wrapper()->is_never_null() == _never_null;
145 }
146
147 bool is_wrapper() const { return true; }
148
149 ciType* unwrap() { return _type; }
150 bool is_never_null() const { return _never_null; }
151 };
152
153 #endif // SHARE_CI_CITYPE_HPP