1 /*
2 * Copyright (c) 1999, 2024, 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.
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23 */
24
25 #ifndef SHARE_CI_CIKLASS_HPP
26 #define SHARE_CI_CIKLASS_HPP
27
28 #include "ci/ciType.hpp"
29 #include "oops/klass.hpp"
30
31 // ciKlass
32 //
33 // This class and its subclasses represent Klass*s in the
34 // HotSpot virtual machine. In the vm, each Klass* contains an
35 // embedded Klass object. ciKlass is subclassed to explicitly
36 // represent the kind of Klass embedded in the Klass*. For
37 // example, a Klass* with an embedded ObjArrayKlass object is
38 // represented in the ciObject hierarchy by the class
39 // ciObjArrayKlass.
40 class ciKlass : public ciType {
41 CI_PACKAGE_ACCESS
42 friend class ciEnv;
43 friend class ciField;
44 friend class ciMethod;
45 friend class ciMethodData;
46 friend class ciObjArrayKlass;
47 friend class ciReceiverTypeData;
48 friend class ciSignature;
49 friend class ciFlatArrayKlass;
50 friend class ciArrayKlass;
51
52 private:
53 ciSymbol* _name;
54 jint _layout_helper;
55
56 protected:
57 ciKlass(Klass* k, ciSymbol* name);
58 ciKlass(ciSymbol* name, BasicType bt);
59
60 Klass* get_Klass() const {
61 Klass* k = (Klass*)_metadata;
62 assert(k != nullptr, "illegal use of unloaded klass");
63 return k;
64 }
65
66 // Certain subklasses have an associated class loader.
67 virtual oop loader() { return nullptr; }
68 virtual jobject loader_handle() { return nullptr; }
69
70 virtual oop protection_domain() { return nullptr; }
71 virtual jobject protection_domain_handle() { return nullptr; }
72
73 const char* type_string() { return "ciKlass"; }
74
75 void print_impl(outputStream* st);
76
77 public:
78 ciKlass(Klass* k);
79
80 // What is the name of this klass?
81 ciSymbol* name() const { return _name; }
82
83 // What is its layout helper value?
84 jint layout_helper() { return _layout_helper; }
85
86 bool is_subtype_of(ciKlass* klass);
87 bool is_subclass_of(ciKlass* klass);
88 juint super_depth();
89 juint super_check_offset();
90 ciKlass* super_of_depth(juint i);
91 static juint primary_super_limit() { return Klass::primary_super_limit(); }
92
93 // Is this ciObject the ciInstanceKlass representing java.lang.Object()?
94 virtual bool is_java_lang_Object() const { return false; }
95
96 // Get the shared parent of two klasses.
97 ciKlass* least_common_ancestor(ciKlass* k);
98
99 virtual bool is_interface() {
100 return false;
101 }
102
103 virtual bool is_abstract() {
104 return false;
105 }
106
107 // Does this type (array, class, interface) have no subtypes?
108 virtual bool is_leaf_type() {
109 return false;
110 }
111
112 virtual bool can_be_inline_klass(bool is_exact = false) {
113 return false;
114 }
115
116 virtual bool can_be_inline_array_klass() {
117 return EnableValhalla && is_java_lang_Object();
118 }
119
120 bool is_in_encoding_range() {
121 Klass* k = get_Klass();
122 bool is_in_encoding_range = CompressedKlassPointers::is_encodable(k);
123 assert(is_in_encoding_range || k->is_interface() || k->is_abstract(), "sanity");
124 return is_in_encoding_range;
125 }
126
127 // Attempt to get a klass using this ciKlass's loader.
128 ciKlass* find_klass(ciSymbol* klass_name);
129 // Note: To find a class from its name string, use ciSymbol::make,
130 // but consider adding to vmSymbols.hpp instead.
131
132 // Get the instance of java.lang.Class corresponding to this klass.
133 ciInstance* java_mirror();
134
135 // Fetch Klass::modifier_flags.
136 jint modifier_flags();
137
138 // Fetch Klass::access_flags.
139 jint access_flags();
140
141 markWord prototype_header() const;
142
143 // Fetch Klass::misc_flags.
144 klass_flags_t misc_flags();
145
146 // What kind of ciObject is this?
147 bool is_klass() const { return true; }
148
149 virtual ciKlass* exact_klass() = 0;
150
151 void print_name_on(outputStream* st);
152
153 const char* external_name() const;
154 };
155
156 #endif // SHARE_CI_CIKLASS_HPP