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=");
132 klass()->print(st);
133 }
134
135
136 ciKlass* ciInstance::java_lang_Class_klass() {
137 VM_ENTRY_MARK;
138 assert(java_lang_Class::as_Klass(get_oop()) != nullptr, "klass is null");
139 return CURRENT_ENV->get_metadata(java_lang_Class::as_Klass(get_oop()))->as_klass();
140 }