1 /*
2 * Copyright (c) 1999, 2023, 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 #include "precompiled.hpp"
26 #include "ci/ciKlass.hpp"
27 #include "ci/ciSymbol.hpp"
28 #include "ci/ciUtilities.inline.hpp"
29 #include "oops/klass.inline.hpp"
30 #include "oops/oop.inline.hpp"
31
32 // ciKlass
33 //
34 // This class represents a Klass* in the HotSpot virtual
35 // machine.
36
37 // ------------------------------------------------------------------
38 // ciKlass::ciKlass
39 ciKlass::ciKlass(Klass* k) : ciType(k) {
40 assert(get_Klass()->is_klass(), "wrong type");
41 Klass* klass = get_Klass();
42 _layout_helper = klass->layout_helper();
43 Symbol* klass_name = klass->name();
44 assert(klass_name != nullptr, "wrong ciKlass constructor");
45 _name = CURRENT_ENV->get_symbol(klass_name);
46 }
47
48 // ------------------------------------------------------------------
49 // ciKlass::ciKlass
50 //
51 // Nameless klass variant.
52 ciKlass::ciKlass(Klass* k, ciSymbol* name) : ciType(k) {
53 assert(get_Klass()->is_klass(), "wrong type");
54 _name = name;
55 _layout_helper = Klass::_lh_neutral_value;
56 }
57
58 // ------------------------------------------------------------------
59 // ciKlass::ciKlass
60 //
61 // Unloaded klass variant.
62 ciKlass::ciKlass(ciSymbol* name, BasicType bt) : ciType(bt) {
63 _name = name;
64 _layout_helper = Klass::_lh_neutral_value;
65 }
66
67 // ------------------------------------------------------------------
68 // ciKlass::is_subtype_of
69 bool ciKlass::is_subtype_of(ciKlass* that) {
70 assert(this->is_loaded(), "must be loaded: %s", this->name()->as_quoted_ascii());
71 assert(that->is_loaded(), "must be loaded: %s", that->name()->as_quoted_ascii());
72
73 // Check to see if the klasses are identical.
74 if (this == that) {
75 return true;
76 }
77
78 bool is_subtype;
79 GUARDED_VM_ENTRY(is_subtype = get_Klass()->is_subtype_of(that->get_Klass());)
80
81 // Ensure consistency with ciInstanceKlass::has_subklass().
82 assert(!that->is_instance_klass() || // array klasses are irrelevant
83 that->is_interface() || // has_subklass is always false for interfaces
84 !is_subtype || that->as_instance_klass()->has_subklass(), "inconsistent");
85
86 return is_subtype;
87 }
88
89 // ------------------------------------------------------------------
90 // ciKlass::is_subclass_of
91 bool ciKlass::is_subclass_of(ciKlass* that) {
92 assert(this->is_loaded(), "must be loaded: %s", this->name()->as_quoted_ascii());
93 assert(that->is_loaded(), "must be loaded: %s", that->name()->as_quoted_ascii());
94
95 // Check to see if the klasses are identical.
96 if (this == that) {
97 return true;
98 }
99
100 bool is_subclass;
101 GUARDED_VM_ENTRY(is_subclass = get_Klass()->is_subclass_of(that->get_Klass());)
102
103 // Ensure consistency with ciInstanceKlass::has_subklass().
104 assert(!that->is_instance_klass() || // array klasses are irrelevant
105 that->is_interface() || // has_subklass is always false for interfaces
106 !is_subclass || that->as_instance_klass()->has_subklass(), "inconsistent");
107
108 return is_subclass;
109 }
110
111 // ------------------------------------------------------------------
112 // ciKlass::super_depth
113 juint ciKlass::super_depth() {
114 assert(is_loaded(), "must be loaded");
115
116 VM_ENTRY_MARK;
117 Klass* this_klass = get_Klass();
118 return this_klass->super_depth();
119 }
120
121 // ------------------------------------------------------------------
122 // ciKlass::super_check_offset
123 juint ciKlass::super_check_offset() {
124 assert(is_loaded(), "must be loaded");
125
126 VM_ENTRY_MARK;
127 Klass* this_klass = get_Klass();
128 return this_klass->super_check_offset();
129 }
130
131 // ------------------------------------------------------------------
132 // ciKlass::super_of_depth
133 ciKlass* ciKlass::super_of_depth(juint i) {
134 assert(is_loaded(), "must be loaded");
135
136 VM_ENTRY_MARK;
137 Klass* this_klass = get_Klass();
138 Klass* super = this_klass->primary_super_of_depth(i);
139 return (super != nullptr) ? CURRENT_THREAD_ENV->get_klass(super) : nullptr;
140 }
141
142 // ------------------------------------------------------------------
143 // ciKlass::least_common_ancestor
144 //
145 // Get the shared parent of two klasses.
146 //
147 // Implementation note: this method currently goes "over the wall"
148 // and does all of the work on the VM side. It could be rewritten
149 // to use the super() method and do all of the work (aside from the
150 // lazy computation of super()) in native mode. This may be
151 // worthwhile if the compiler is repeatedly requesting the same lca
152 // computation or possibly if most of the superklasses have already
153 // been created as ciObjects anyway. Something to think about...
154 ciKlass*
155 ciKlass::least_common_ancestor(ciKlass* that) {
156 assert(is_loaded() && that->is_loaded(), "must be loaded");
157 // Check to see if the klasses are identical.
158 if (this == that) {
159 return this;
160 }
161
162 VM_ENTRY_MARK;
163 Klass* this_klass = get_Klass();
164 Klass* that_klass = that->get_Klass();
165 Klass* lca = this_klass->LCA(that_klass);
166
167 // Many times the LCA will be either this_klass or that_klass.
168 // Treat these as special cases.
169 if (lca == that_klass) {
170 assert(this->is_subtype_of(that), "sanity");
171 return that;
172 }
173 if (this_klass == lca) {
174 assert(that->is_subtype_of(this), "sanity");
175 return this;
176 }
177
178 // Create the ciInstanceKlass for the lca.
179 ciKlass* result =
180 CURRENT_THREAD_ENV->get_klass(lca);
181
182 assert(this->is_subtype_of(result) && that->is_subtype_of(result), "sanity");
183 return result;
184 }
185
186 // ------------------------------------------------------------------
187 // ciKlass::find_klass
188 //
189 // Find a klass using this klass's class loader.
190 ciKlass* ciKlass::find_klass(ciSymbol* klass_name) {
191 assert(is_loaded(), "cannot find_klass through an unloaded klass");
192 return CURRENT_ENV->get_klass_by_name(this,
193 klass_name, false);
194 }
195
196 // ------------------------------------------------------------------
197 // ciKlass::java_mirror
198 //
199 // Get the instance of java.lang.Class corresponding to this klass.
200 // If it is an unloaded instance or array klass, return an unloaded
201 // mirror object of type Class.
202 ciInstance* ciKlass::java_mirror() {
203 GUARDED_VM_ENTRY(
204 if (!is_loaded())
205 return ciEnv::current()->get_unloaded_klass_mirror(this);
206 oop java_mirror = get_Klass()->java_mirror();
207 return CURRENT_ENV->get_instance(java_mirror);
208 )
209 }
210
211 // ------------------------------------------------------------------
212 // ciKlass::modifier_flags
213 jint ciKlass::modifier_flags() {
214 assert(is_loaded(), "not loaded");
215 GUARDED_VM_ENTRY(
216 return get_Klass()->modifier_flags();
217 )
218 }
219
220 // ------------------------------------------------------------------
221 // ciKlass::access_flags
222 jint ciKlass::access_flags() {
223 assert(is_loaded(), "not loaded");
224 GUARDED_VM_ENTRY(
225 return get_Klass()->access_flags().as_int();
226 )
227 }
228
229 // ------------------------------------------------------------------
230 // ciKlass::print_impl
231 //
232 // Implementation of the print method
233 void ciKlass::print_impl(outputStream* st) {
234 st->print(" name=");
235 print_name_on(st);
236 st->print(" loaded=%s", (is_loaded() ? "true" : "false"));
237 }
238
239 // ------------------------------------------------------------------
240 // ciKlass::print_name
241 //
242 // Print the name of this klass
243 void ciKlass::print_name_on(outputStream* st) {
244 name()->print_symbol_on(st);
245 }
246
247 const char* ciKlass::external_name() const {
248 GUARDED_VM_ENTRY(
249 return get_Klass()->external_name();
250 )
251 }