1 /*
2 * Copyright (c) 1999, 2025, 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 #include "runtime/arguments.hpp"
31
32 // ciKlass
33 //
34 // This class and its subclasses represent Klass*s in the
35 // HotSpot virtual machine. In the vm, each Klass* contains an
36 // embedded Klass object. ciKlass is subclassed to explicitly
37 // represent the kind of Klass embedded in the Klass*. For
38 // example, a Klass* with an embedded ObjArrayKlass object is
39 // represented in the ciObject hierarchy by the class
40 // ciObjArrayKlass.
41 class ciKlass : public ciType {
42 CI_PACKAGE_ACCESS
43 friend class ciEnv;
44 friend class ciField;
45 friend class ciMethod;
46 friend class ciMethodData;
47 friend class ciObjArrayKlass;
48 friend class ciReceiverTypeData;
49 friend class ciSignature;
50 friend class ciFlatArrayKlass;
51 friend class ciArrayKlass;
52
53 private:
54 ciSymbol* _name;
55 jint _layout_helper;
56
57 protected:
58 ciKlass(Klass* k, ciSymbol* name);
59 ciKlass(ciSymbol* name, BasicType bt);
60
61 Klass* get_Klass() const {
62 Klass* k = (Klass*)_metadata;
63 assert(k != nullptr, "illegal use of unloaded klass");
64 return k;
65 }
66
67 // Certain subklasses have an associated class loader.
68 virtual oop loader() { return nullptr; }
69 virtual jobject loader_handle() { return nullptr; }
70
71 const char* type_string() { return "ciKlass"; }
72
73 void print_impl(outputStream* st);
74
75 public:
76 ciKlass(Klass* k);
77
78 // What is the name of this klass?
79 ciSymbol* name() const { return _name; }
80
81 // What is its layout helper value?
82 jint layout_helper() { return _layout_helper; }
83
84 bool is_subtype_of(ciKlass* klass);
85 bool is_subclass_of(ciKlass* klass);
86 juint super_depth();
87 juint super_check_offset();
88 ciKlass* super_of_depth(juint i);
89 static juint primary_super_limit() { return Klass::primary_super_limit(); }
90
91 // Is this ciObject the ciInstanceKlass representing java.lang.Object()?
92 virtual bool is_java_lang_Object() const { return false; }
93
94 // Get the shared parent of two klasses.
95 ciKlass* least_common_ancestor(ciKlass* k);
96
97 virtual bool is_interface() {
98 return false;
99 }
100
101 virtual bool is_abstract() {
102 return false;
103 }
104
105 // Does this type (array, class, interface) have no subtypes?
106 virtual bool is_leaf_type() {
107 return false;
108 }
109
110 virtual bool can_be_inline_klass(bool is_exact = false) {
111 return false;
112 }
113
114 virtual bool can_be_inline_array_klass() {
115 return Arguments::is_valhalla_enabled() && is_java_lang_Object();
116 }
117
118 bool is_in_encoding_range() {
119 Klass* k = get_Klass();
120 bool is_in_encoding_range = CompressedKlassPointers::is_encodable(k);
121 assert(is_in_encoding_range, "sanity");
122 return is_in_encoding_range;
123 }
124
125 // Attempt to get a klass using this ciKlass's loader.
126 ciKlass* find_klass(ciSymbol* klass_name);
127 // Note: To find a class from its name string, use ciSymbol::make,
128 // but consider adding to vmSymbols.hpp instead.
129
130 // Get the instance of java.lang.Class corresponding to this klass.
131 ciInstance* java_mirror();
132
133 // Fetch modifier flags.
134 jint modifier_flags();
135
136 markWord prototype_header() const;
137
138 // Fetch Klass::misc_flags.
139 klass_flags_t misc_flags();
140
141 // What kind of ciObject is this?
142 bool is_klass() const { return true; }
143
144 virtual ciKlass* exact_klass() = 0;
145
146 void print_name_on(outputStream* st);
147
148 const char* external_name() const;
149
150 juint prototype_header_offset();
151 uintptr_t prototype_header();
152 };
153
154 #endif // SHARE_CI_CIKLASS_HPP