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.
22 *
23 */
24
25 #include "ci/ciInstanceKlass.hpp"
26 #include "ci/ciObjArrayKlass.hpp"
27 #include "ci/ciSymbol.hpp"
28 #include "ci/ciUtilities.inline.hpp"
29 #include "oops/inlineKlass.inline.hpp"
30 #include "oops/objArrayKlass.hpp"
31 #include "runtime/signature.hpp"
32
33 // ciObjArrayKlass
34 //
35 // This class represents a Klass* in the HotSpot virtual machine
36 // whose Klass part is an ObjArrayKlass.
37
38 // ------------------------------------------------------------------
39 // ciObjArrayKlass::ciObjArrayKlass
40 //
41 // Constructor for loaded object array klasses.
42 ciObjArrayKlass::ciObjArrayKlass(Klass* k) : ciArrayKlass(k) {
43 assert(get_Klass()->is_objArray_klass(), "wrong type");
44 Klass* element_Klass = get_ObjArrayKlass()->bottom_klass();
45 _base_element_klass = CURRENT_ENV->get_klass(element_Klass);
46 assert(_base_element_klass->is_instance_klass() ||
47 _base_element_klass->is_type_array_klass(), "bad base klass");
48 if (dimension() == 1) {
49 _element_klass = _base_element_klass;
50 } else {
51 _element_klass = nullptr;
52 }
53 if (!ciObjectFactory::is_initialized()) {
54 assert(_element_klass->is_java_lang_Object(), "only arrays of object are shared");
55 }
56 }
57
58 // ------------------------------------------------------------------
59 // ciObjArrayKlass::ciObjArrayKlass
60 //
61 // Constructor for unloaded object array klasses.
62 ciObjArrayKlass::ciObjArrayKlass(ciSymbol* array_name,
63 ciKlass* base_element_klass,
64 int dimension)
65 : ciArrayKlass(array_name,
66 dimension, T_OBJECT) {
67 _base_element_klass = base_element_klass;
68 assert(_base_element_klass->is_instance_klass() ||
69 _base_element_klass->is_type_array_klass() ||
70 _base_element_klass->is_flat_array_klass(), "bad base klass");
71 if (dimension == 1) {
72 _element_klass = base_element_klass;
73 } else {
74 _element_klass = nullptr;
75 }
76 }
77
78 // ------------------------------------------------------------------
79 // ciObjArrayKlass::element_klass
80 //
81 // What is the one-level element type of this array?
82 ciKlass* ciObjArrayKlass::element_klass() {
83 if (_element_klass == nullptr) {
84 assert(dimension() > 1, "_element_klass should not be null");
85 // Produce the element klass.
86 if (is_loaded()) {
87 VM_ENTRY_MARK;
88 Klass* element_Klass = get_ObjArrayKlass()->element_klass();
89 _element_klass = CURRENT_THREAD_ENV->get_klass(element_Klass);
90 } else {
91 VM_ENTRY_MARK;
92 // We are an unloaded array klass. Attempt to fetch our
93 // element klass by name.
94 _element_klass = CURRENT_THREAD_ENV->get_klass_by_name_impl(
95 this,
96 constantPoolHandle(),
97 construct_array_name(base_element_klass()->name(),
98 dimension() - 1),
99 false);
100 }
101 }
102 return _element_klass;
103 }
104
105 // ------------------------------------------------------------------
106 // ciObjArrayKlass::construct_array_name
107 //
108 // Build an array name from an element name and a dimension.
109 ciSymbol* ciObjArrayKlass::construct_array_name(ciSymbol* element_name,
110 int dimension) {
111 EXCEPTION_CONTEXT;
112 int element_len = element_name->utf8_length();
113 int buflen = dimension + element_len + 3; // '['+ + 'L'? + (element) + ';'? + '\0'
114 char* name = CURRENT_THREAD_ENV->name_buffer(buflen);
115 int pos = 0;
116 for ( ; pos < dimension; pos++) {
117 name[pos] = JVM_SIGNATURE_ARRAY;
118 }
119 Symbol* base_name_sym = element_name->get_symbol();
120 if (Signature::is_array(base_name_sym) ||
121 Signature::has_envelope(base_name_sym)) {
122 strncpy(&name[pos], (char*)element_name->base(), element_len);
123 name[pos + element_len] = '\0';
124 } else {
125 name[pos++] = JVM_SIGNATURE_CLASS;
126 strncpy(&name[pos], (char*)element_name->base(), element_len);
127 name[pos + element_len] = JVM_SIGNATURE_ENDCLASS;
128 name[pos + element_len + 1] = '\0';
129 }
130 return ciSymbol::make(name);
131 }
132
133 // ------------------------------------------------------------------
134 // ciObjArrayKlass::make_impl
135 //
136 // Implementation of make.
137 ciObjArrayKlass* ciObjArrayKlass::make_impl(ciKlass* element_klass) {
138 if (element_klass->is_loaded()) {
139 EXCEPTION_CONTEXT;
140 // The element klass is loaded
141 Klass* array = element_klass->get_Klass()->array_klass(THREAD);
142 if (HAS_PENDING_EXCEPTION) {
143 CLEAR_PENDING_EXCEPTION;
144 CURRENT_THREAD_ENV->record_out_of_memory_failure();
145 return ciEnv::unloaded_ciobjarrayklass();
146 }
147 return CURRENT_THREAD_ENV->get_obj_array_klass(array);
148 }
149
150 // The array klass was unable to be made or the element klass was not loaded.
151 ciSymbol* array_name = construct_array_name(element_klass->name(), 1);
152 if (array_name == ciEnv::unloaded_cisymbol()) {
153 return ciEnv::unloaded_ciobjarrayklass();
154 }
155 return
156 CURRENT_ENV->get_unloaded_klass(element_klass, array_name)
157 ->as_obj_array_klass();
158 }
159
160 // ------------------------------------------------------------------
161 // ciObjArrayKlass::make
162 //
163 // Make an array klass corresponding to the specified primitive type.
164 ciObjArrayKlass* ciObjArrayKlass::make(ciKlass* element_klass) {
165 GUARDED_VM_ENTRY(return make_impl(element_klass);)
166 }
167
168 ciObjArrayKlass* ciObjArrayKlass::make(ciKlass* element_klass, int dims) {
169 ciKlass* klass = element_klass;
170 for (int i = 0; i < dims; i++) {
171 klass = ciObjArrayKlass::make(klass);
172 }
173 return klass->as_obj_array_klass();
174 }
175
176 ciKlass* ciObjArrayKlass::exact_klass() {
177 if (!is_loaded()) {
178 return nullptr;
179 }
180 ciType* base = base_element_type();
181 if (base->is_instance_klass()) {
182 ciInstanceKlass* ik = base->as_instance_klass();
183 // Even though MyValue is final, [LMyValue is only exact if the array
184 // is null-free due to null-free [LMyValue <: null-able [LMyValue.
185 if (ik->is_inlinetype() && !is_elem_null_free()) {
186 return nullptr;
187 }
188 if (ik->exact_klass() != nullptr) {
189 return this;
190 }
191 } else if (base->is_primitive_type()) {
192 return this;
193 }
194 return nullptr;
195 }