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/ciConstant.hpp"
26 #include "ci/ciField.hpp"
27 #include "ci/ciInstance.hpp"
28 #include "ci/ciInstanceKlass.hpp"
29 #include "ci/ciNullObject.hpp"
30 #include "ci/ciUtilities.inline.hpp"
31 #include "classfile/javaClasses.inline.hpp"
32 #include "classfile/vmClasses.hpp"
33 #include "oops/oop.inline.hpp"
34
35 // ciInstance
36 //
37 // This class represents an instanceOop in the HotSpot virtual
38 // machine.
39
40 // ------------------------------------------------------------------
41 // ciObject::java_mirror_type
42 ciType* ciInstance::java_mirror_type() {
43 VM_ENTRY_MARK;
44 oop m = get_oop();
45 // Return null if it is not java.lang.Class.
46 if (m == nullptr || m->klass() != vmClasses::Class_klass()) {
47 return nullptr;
48 }
49 // Return either a primitive type or a klass.
50 if (java_lang_Class::is_primitive(m)) {
51 return ciType::make(java_lang_Class::primitive_type(m));
52 } else {
53 Klass* k = java_lang_Class::as_Klass(m);
54 assert(k != nullptr, "");
55 return CURRENT_THREAD_ENV->get_klass(k);
56 }
57 }
58
59 // ------------------------------------------------------------------
60 // ciInstance::field_value_impl
61 ciConstant ciInstance::field_value_impl(BasicType field_btype, int offset) {
62 ciConstant value = check_constant_value_cache(offset, field_btype);
63 if (value.is_valid()) {
64 return value;
65 }
66 VM_ENTRY_MARK;
67 oop obj = get_oop();
68 assert(obj != nullptr, "bad oop");
69 switch(field_btype) {
70 case T_BYTE: value = ciConstant(field_btype, obj->byte_field(offset)); break;
71 case T_CHAR: value = ciConstant(field_btype, obj->char_field(offset)); break;
72 case T_SHORT: value = ciConstant(field_btype, obj->short_field(offset)); break;
73 case T_BOOLEAN: value = ciConstant(field_btype, obj->bool_field(offset)); break;
74 case T_INT: value = ciConstant(field_btype, obj->int_field(offset)); break;
75 case T_FLOAT: value = ciConstant(obj->float_field(offset)); break;
76 case T_DOUBLE: value = ciConstant(obj->double_field(offset)); break;
77 case T_LONG: value = ciConstant(obj->long_field(offset)); break;
78 case T_OBJECT: // fall through
79 case T_ARRAY: {
80 oop o = obj->obj_field(offset);
81
82 // A field will be "constant" if it is known always to be
83 // a non-null reference to an instance of a particular class,
84 // or to a particular array. This can happen even if the instance
85 // or array is not perm. In such a case, an "unloaded" ciArray
86 // or ciInstance is created. The compiler may be able to use
87 // information about the object's class (which is exact) or length.
88
89 if (o == nullptr) {
90 value = ciConstant(field_btype, ciNullObject::make());
91 } else {
92 value = ciConstant(field_btype, CURRENT_ENV->get_object(o));
93 }
94 break;
95 }
96 default:
97 fatal("no field value: %s", type2name(field_btype));
98 }
99 add_to_constant_value_cache(offset, value);
100 return value;
101 }
102
103 // ------------------------------------------------------------------
104 // ciInstance::field_value
105 //
106 // Constant value of a field.
107 ciConstant ciInstance::field_value(ciField* field) {
108 assert(is_loaded(), "invalid access - must be loaded");
109 assert(field->holder()->is_loaded(), "invalid access - holder must be loaded");
110 assert(field->is_static() || klass()->is_subclass_of(field->holder()), "invalid access - must be subclass");
111 return field_value_impl(field->type()->basic_type(), field->offset_in_bytes());
112 }
113
114 // ------------------------------------------------------------------
115 // ciInstance::field_value_by_offset
116 //
117 // Constant value of a field at the specified offset.
118 ciConstant ciInstance::field_value_by_offset(int field_offset) {
119 ciInstanceKlass* ik = klass()->as_instance_klass();
120 ciField* field = ik->get_field_by_offset(field_offset, false);
121 if (field == nullptr)
122 return ciConstant(); // T_ILLEGAL
123 return field_value(field);
124 }
125
126 // ------------------------------------------------------------------
127 // ciInstance::print_impl
128 //
129 // Implementation of the print method.
130 void ciInstance::print_impl(outputStream* st) {
131 st->print(" type=");
|
1 /*
2 * Copyright (c) 1999, 2026, 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/ciConstant.hpp"
26 #include "ci/ciField.hpp"
27 #include "ci/ciInlineKlass.hpp"
28 #include "ci/ciInstance.hpp"
29 #include "ci/ciInstanceKlass.hpp"
30 #include "ci/ciNullObject.hpp"
31 #include "ci/ciUtilities.inline.hpp"
32 #include "classfile/javaClasses.inline.hpp"
33 #include "classfile/vmClasses.hpp"
34 #include "oops/fieldStreams.hpp"
35 #include "oops/fieldStreams.inline.hpp"
36 #include "oops/oop.inline.hpp"
37 #include "oops/valuePayload.inline.hpp"
38
39 // ciInstance
40 //
41 // This class represents an instanceOop in the HotSpot virtual
42 // machine.
43
44 // ------------------------------------------------------------------
45 // ciObject::java_mirror_type
46 ciType* ciInstance::java_mirror_type() {
47 VM_ENTRY_MARK;
48 oop m = get_oop();
49 // Return null if it is not java.lang.Class.
50 if (m == nullptr || m->klass() != vmClasses::Class_klass()) {
51 return nullptr;
52 }
53 // Return either a primitive type or a klass.
54 if (java_lang_Class::is_primitive(m)) {
55 return ciType::make(java_lang_Class::primitive_type(m));
56 } else {
57 Klass* k = java_lang_Class::as_Klass(m);
58 assert(k != nullptr, "");
59 return CURRENT_THREAD_ENV->get_klass(k);
60 }
61 }
62
63 // ------------------------------------------------------------------
64 // ciInstance::field_value_impl
65 ciConstant ciInstance::field_value_impl(ciField* field) {
66 BasicType field_bt = field->type()->basic_type();
67 int offset = field->offset_in_bytes();
68 ciConstant value = check_constant_value_cache(offset, field_bt);
69 if (value.is_valid()) {
70 return value;
71 }
72 VM_ENTRY_MARK;
73 oop obj = get_oop();
74 assert(obj != nullptr, "bad oop");
75 switch(field_bt) {
76 case T_BYTE: value = ciConstant(field_bt, obj->byte_field(offset)); break;
77 case T_CHAR: value = ciConstant(field_bt, obj->char_field(offset)); break;
78 case T_SHORT: value = ciConstant(field_bt, obj->short_field(offset)); break;
79 case T_BOOLEAN: value = ciConstant(field_bt, obj->bool_field(offset)); break;
80 case T_INT: value = ciConstant(field_bt, obj->int_field(offset)); break;
81 case T_FLOAT: value = ciConstant(obj->float_field(offset)); break;
82 case T_DOUBLE: value = ciConstant(obj->double_field(offset)); break;
83 case T_LONG: value = ciConstant(obj->long_field(offset)); break;
84 case T_OBJECT: // fall through
85 case T_ARRAY: {
86 if (field->is_flat()) {
87 assert(field->is_atomic(), "do not query atomically a non-atomic flat field");
88 InlineKlass* vk = field->type()->as_inline_klass()->get_InlineKlass();
89 FlatValuePayload payload = FlatValuePayload::construct_from_parts(obj, offset, vk, field->layout_kind());
90 oop res = payload.read(THREAD);
91 if (HAS_PENDING_EXCEPTION) {
92 CLEAR_PENDING_EXCEPTION;
93 return ciConstant();
94 }
95 value = ciConstant(field_bt, CURRENT_ENV->get_object(res));
96 } else {
97 oop o = obj->obj_field(offset);
98
99 // A field will be "constant" if it is known always to be
100 // a non-null reference to an instance of a particular class,
101 // or to a particular array. This can happen even if the instance
102 // or array is not perm. In such a case, an "unloaded" ciArray
103 // or ciInstance is created. The compiler may be able to use
104 // information about the object's class (which is exact) or length.
105
106 if (o == nullptr) {
107 value = ciConstant(field_bt, ciNullObject::make());
108 } else {
109 value = ciConstant(field_bt, CURRENT_ENV->get_object(o));
110 }
111 }
112 break;
113 }
114 default:
115 fatal("no field value: %s", type2name(field_bt));
116 }
117 add_to_constant_value_cache(offset, value);
118 return value;
119 }
120
121 // ------------------------------------------------------------------
122 // ciInstance::field_value
123 //
124 // Constant value of a field of any kind: a declared field, or a leaf field.
125 // For a flat declared field, a cached copy of the value object is returned.
126 //
127 // Since stable fields can be treated as "constant" but are not really, we need
128 // to cache the value of fields so that the compiler will observe only one value
129 // per field. We also need to ensure that leaf fields from a single stable
130 // flat declared field will be observed to be consistent with each other.
131 //
132 // To do so, we need to always fetch the whole declared field containing the
133 // desired field. If we want a sub-field of a flat field, we then extract the field
134 // out of the cached copy, using sub_field_value.
135 //
136 // In the case we request a non-flat field, or a declared field (possibly flat), there
137 // is no sub-field to extract and sub_field_value will not be called.
138 ciConstant ciInstance::field_value(ciField* field) {
139 assert(is_loaded(), "invalid access - must be loaded");
140 assert(field->holder()->is_loaded(), "invalid access - holder must be loaded");
141 assert(field->is_static() || field->holder()->is_inlinetype() || klass()->is_subclass_of(field->holder()),
142 "invalid access - must be subclass");
143 ciInstanceKlass* klass = this->klass()->as_instance_klass();
144 int containing_field_idx = klass->field_index_by_offset(field->offset_in_bytes());
145 ciField* containing_field = klass->declared_nonstatic_field_at(containing_field_idx);
146 if (containing_field->is_flat() && !containing_field->is_atomic()) {
147 assert(field != containing_field, "do not ask for a non atomic declared field");
148 return field_value_impl(field);
149 }
150 ciConstant containing_field_value = field_value_impl(containing_field);
151 if (!containing_field_value.is_valid()) {
152 return ciConstant();
153 }
154 if (field->original_holder() == nullptr) {
155 return containing_field_value;
156 }
157 ciObject* obj = containing_field_value.as_object();
158 if (obj->is_instance()) {
159 ciInstance* inst = obj->as_instance();
160 // inst->klass() must be an inline klass since it is the value of a flat field.
161 ciInlineKlass* inst_klass = inst->klass()->as_inline_klass();
162 ciField* field_in_value_klass = inst_klass->get_field_by_offset(inst_klass->payload_offset() + field->offset_in_bytes() - containing_field->offset_in_bytes(), false);
163 return inst->sub_field_value(field_in_value_klass);
164 } else if (obj->is_null_object()) {
165 return ciConstant::make_zero_or_null(field->type()->basic_type());
166 }
167 // obj should not be an array since we are trying to get a field inside it
168 ShouldNotReachHere();
169 return ciConstant();
170 }
171
172 // Extract a leaf field from a value object.
173 //
174 // This is used by field_value when getting the value of a sub-field. field_value
175 // will take care of getting the value of the declared field containing the requested
176 // field, and of caching (see the comment on field_value for why). But if we want the
177 // value of a sub-field, we need to extract it from the value of the declared field
178 // containing the said sub-field. This is what this function does.
179 //
180 // This is meant for internal used only. In particular, this function does not cache
181 // the result and must be called only on already cached values (to ensure consistency).
182 // field_value takes care of that.
183 ciConstant ciInstance::sub_field_value(ciField* field) {
184 precond(klass()->is_inlinetype());
185 precond(!field->is_flat());
186 int offset = field->offset_in_bytes();
187 BasicType field_btype = field->type()->basic_type();
188
189 ciConstant value;
190 VM_ENTRY_MARK;
191 oop obj = get_oop();
192 assert(obj != nullptr, "bad oop");
193 switch(field_btype) {
194 case T_BYTE: value = ciConstant(field_btype, obj->byte_field(offset)); break;
195 case T_CHAR: value = ciConstant(field_btype, obj->char_field(offset)); break;
196 case T_SHORT: value = ciConstant(field_btype, obj->short_field(offset)); break;
197 case T_BOOLEAN: value = ciConstant(field_btype, obj->bool_field(offset)); break;
198 case T_INT: value = ciConstant(field_btype, obj->int_field(offset)); break;
199 case T_FLOAT: value = ciConstant(obj->float_field(offset)); break;
200 case T_DOUBLE: value = ciConstant(obj->double_field(offset)); break;
201 case T_LONG: value = ciConstant(obj->long_field(offset)); break;
202 case T_OBJECT: // fall through
203 case T_ARRAY: {
204 oop o = obj->obj_field(offset);
205
206 // A field will be "constant" if it is known always to be
207 // a non-null reference to an instance of a particular class,
208 // or to a particular array. This can happen even if the instance
209 // or array is not perm. In such a case, an "unloaded" ciArray
210 // or ciInstance is created. The compiler may be able to use
211 // information about the object's class (which is exact) or length.
212
213 if (o == nullptr) {
214 value = ciConstant(field_btype, ciNullObject::make());
215 } else {
216 value = ciConstant(field_btype, CURRENT_ENV->get_object(o));
217 }
218 break;
219 }
220 default:
221 fatal("no field value: %s", type2name(field_btype));
222 }
223 return value;
224 }
225
226 // ------------------------------------------------------------------
227 // ciInstance::field_value_by_offset
228 //
229 // Constant value of a field at the specified offset.
230 ciConstant ciInstance::field_value_by_offset(int field_offset) {
231 ciInstanceKlass* ik = klass()->as_instance_klass();
232 ciField* field = ik->get_field_by_offset(field_offset, false);
233 if (field == nullptr)
234 return ciConstant(); // T_ILLEGAL
235 return field_value(field);
236 }
237
238 // ------------------------------------------------------------------
239 // ciInstance::print_impl
240 //
241 // Implementation of the print method.
242 void ciInstance::print_impl(outputStream* st) {
243 st->print(" type=");
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