1 /*
2 * Copyright (c) 1999, 2021, 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/ciInstanceKlass.hpp"
27 #include "ci/ciObjArrayKlass.hpp"
28 #include "ci/ciSymbol.hpp"
29 #include "ci/ciUtilities.inline.hpp"
30 #include "oops/inlineKlass.inline.hpp"
31 #include "oops/objArrayKlass.hpp"
32 #include "runtime/signature.hpp"
33
34 // ciObjArrayKlass
35 //
36 // This class represents a Klass* in the HotSpot virtual machine
37 // whose Klass part is an ObjArrayKlass.
38
39 // ------------------------------------------------------------------
40 // ciObjArrayKlass::ciObjArrayKlass
41 //
42 // Constructor for loaded object array klasses.
43 ciObjArrayKlass::ciObjArrayKlass(Klass* k) : ciArrayKlass(k) {
44 assert(get_Klass()->is_objArray_klass(), "wrong type");
45 Klass* element_Klass = get_ObjArrayKlass()->bottom_klass();
46 _base_element_klass = CURRENT_ENV->get_klass(element_Klass);
47 assert(_base_element_klass->is_instance_klass() ||
48 _base_element_klass->is_type_array_klass(), "bad base klass");
49 if (dimension() == 1) {
50 _element_klass = _base_element_klass;
51 } else {
52 _element_klass = NULL;
53 }
54 if (!ciObjectFactory::is_initialized()) {
55 assert(_element_klass->is_java_lang_Object(), "only arrays of object are shared");
56 }
57 _null_free = k->name()->is_Q_array_signature() && k->name()->char_at(1) == JVM_SIGNATURE_PRIMITIVE_OBJECT;
58 }
59
60 // ------------------------------------------------------------------
61 // ciObjArrayKlass::ciObjArrayKlass
62 //
63 // Constructor for unloaded object array klasses.
64 ciObjArrayKlass::ciObjArrayKlass(ciSymbol* array_name,
65 ciKlass* base_element_klass,
66 int dimension)
67 : ciArrayKlass(array_name,
68 dimension, T_OBJECT) {
69 _base_element_klass = base_element_klass;
70 assert(_base_element_klass->is_instance_klass() ||
71 _base_element_klass->is_type_array_klass() ||
72 _base_element_klass->is_flat_array_klass(), "bad base klass");
73 if (dimension == 1) {
74 _element_klass = base_element_klass;
75 } else {
76 _element_klass = NULL;
77 }
78 _null_free = array_name->is_Q_array_signature() && array_name->char_at(1) == JVM_SIGNATURE_PRIMITIVE_OBJECT;
79 }
80
81 // ------------------------------------------------------------------
82 // ciObjArrayKlass::element_klass
83 //
84 // What is the one-level element type of this array?
85 ciKlass* ciObjArrayKlass::element_klass() {
86 if (_element_klass == NULL) {
87 assert(dimension() > 1, "_element_klass should not be NULL");
88 // Produce the element klass.
89 if (is_loaded()) {
90 VM_ENTRY_MARK;
91 Klass* element_Klass = get_ObjArrayKlass()->element_klass();
92 _element_klass = CURRENT_THREAD_ENV->get_klass(element_Klass);
93 } else {
94 VM_ENTRY_MARK;
95 // We are an unloaded array klass. Attempt to fetch our
96 // element klass by name.
97 _element_klass = CURRENT_THREAD_ENV->get_klass_by_name_impl(
98 this,
99 constantPoolHandle(),
100 construct_array_name(base_element_klass()->name(),
101 dimension() - 1),
102 false);
103 }
104 }
105 return _element_klass;
106 }
107
108 // ------------------------------------------------------------------
109 // ciObjArrayKlass::construct_array_name
110 //
111 // Build an array name from an element name and a dimension.
112 ciSymbol* ciObjArrayKlass::construct_array_name(ciSymbol* element_name,
113 int dimension) {
114 EXCEPTION_CONTEXT;
115 int element_len = element_name->utf8_length();
116 int buflen = dimension + element_len + 3; // '['+ + 'L'? + (element) + ';'? + '\0'
117 char* name = CURRENT_THREAD_ENV->name_buffer(buflen);
118 int pos = 0;
119 for ( ; pos < dimension; pos++) {
120 name[pos] = JVM_SIGNATURE_ARRAY;
121 }
122 Symbol* base_name_sym = element_name->get_symbol();
123 assert(base_name_sym->char_at(0) != JVM_SIGNATURE_PRIMITIVE_OBJECT, "unloaded array klass element should not have Q-type");
124 if (Signature::is_array(base_name_sym) ||
125 Signature::has_envelope(base_name_sym)) {
126 strncpy(&name[pos], (char*)element_name->base(), element_len);
127 name[pos + element_len] = '\0';
128 } else {
129 name[pos++] = JVM_SIGNATURE_CLASS;
130 strncpy(&name[pos], (char*)element_name->base(), element_len);
131 name[pos + element_len] = JVM_SIGNATURE_ENDCLASS;
132 name[pos + element_len + 1] = '\0';
133 }
134 return ciSymbol::make(name);
135 }
136
137 // ------------------------------------------------------------------
138 // ciObjArrayKlass::make_impl
139 //
140 // Implementation of make.
141 ciObjArrayKlass* ciObjArrayKlass::make_impl(ciKlass* element_klass) {
142 if (element_klass->is_loaded()) {
143 EXCEPTION_CONTEXT;
144 // The element klass is loaded
145 Klass* array = element_klass->get_Klass()->array_klass(THREAD);
146 if (HAS_PENDING_EXCEPTION) {
147 CLEAR_PENDING_EXCEPTION;
148 CURRENT_THREAD_ENV->record_out_of_memory_failure();
149 return ciEnv::unloaded_ciobjarrayklass();
150 }
151 return CURRENT_THREAD_ENV->get_obj_array_klass(array);
152 }
153
154 // The array klass was unable to be made or the element klass was not loaded.
155 ciSymbol* array_name = construct_array_name(element_klass->name(), 1);
156 if (array_name == ciEnv::unloaded_cisymbol()) {
157 return ciEnv::unloaded_ciobjarrayklass();
158 }
159 return
160 CURRENT_ENV->get_unloaded_klass(element_klass, array_name)
161 ->as_obj_array_klass();
162 }
163
164 // ------------------------------------------------------------------
165 // ciObjArrayKlass::make
166 //
167 // Make an array klass corresponding to the specified primitive type.
168 ciObjArrayKlass* ciObjArrayKlass::make(ciKlass* element_klass) {
169 GUARDED_VM_ENTRY(return make_impl(element_klass);)
170 }
171
172 ciObjArrayKlass* ciObjArrayKlass::make(ciKlass* element_klass, int dims) {
173 ciKlass* klass = element_klass;
174 for (int i = 0; i < dims; i++) {
175 klass = ciObjArrayKlass::make(klass);
176 }
177 return klass->as_obj_array_klass();
178 }
179
180 ciKlass* ciObjArrayKlass::exact_klass() {
181 // Even if MyValue is exact, [LMyValue is not exact due to [QMyValue <: [LMyValue.
182 if (!is_elem_null_free() && (!is_loaded() || element_klass()->is_inlinetype())) {
183 return NULL;
184 }
185 ciType* base = base_element_type();
186 if (base->is_instance_klass()) {
187 ciInstanceKlass* ik = base->as_instance_klass();
188 if (ik->exact_klass() != NULL) {
189 return this;
190 }
191 } else if (base->is_primitive_type()) {
192 return this;
193 }
194 return NULL;
195 }