1 /*
2 * Copyright (c) 1997, 2018, 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 #ifndef SHARE_VM_RUNTIME_FIELDDESCRIPTOR_HPP
26 #define SHARE_VM_RUNTIME_FIELDDESCRIPTOR_HPP
27
28 #include "oops/constantPool.hpp"
29 #include "oops/fieldInfo.hpp"
30 #include "oops/instanceKlass.hpp"
31 #include "oops/symbol.hpp"
32 #include "runtime/fieldType.hpp"
33 #include "utilities/accessFlags.hpp"
34 #include "utilities/constantTag.hpp"
35
36 // A fieldDescriptor describes the attributes of a single field (instance or class variable).
37 // It needs the class constant pool to work (because it only holds indices into the pool
38 // rather than the actual info).
39
40 class fieldDescriptor {
41 private:
42 AccessFlags _access_flags;
43 int _index; // the field index
44 constantPoolHandle _cp;
45
46 // update the access_flags for the field in the klass
47 void update_klass_field_access_flag() {
48 InstanceKlass* ik = field_holder();
49 ik->field(index())->set_access_flags(_access_flags.as_short());
50 }
51
52 FieldInfo* field() const {
53 InstanceKlass* ik = field_holder();
54 return ik->field(_index);
55 }
56
57 public:
58 fieldDescriptor() {
59 DEBUG_ONLY(_index = badInt);
60 }
61 fieldDescriptor(InstanceKlass* ik, int index) {
62 DEBUG_ONLY(_index = badInt);
63 reinitialize(ik, index);
64 }
65 Symbol* name() const {
66 return field()->name(_cp());
67 }
68 Symbol* signature() const {
69 return field()->signature(_cp());
70 }
71 InstanceKlass* field_holder() const { return _cp->pool_holder(); }
72 ConstantPool* constants() const { return _cp(); }
73 AccessFlags access_flags() const { return _access_flags; }
74 oop loader() const;
75 // Offset (in words) of field from start of instanceOop / Klass*
76 int offset() const { return field()->offset(); }
77 Symbol* generic_signature() const;
78 int index() const { return _index; }
79 AnnotationArray* annotations() const;
80 AnnotationArray* type_annotations() const;
81
82 // Initial field value
83 bool has_initial_value() const { return field()->initval_index() != 0; }
84 int initial_value_index() const { return field()->initval_index(); }
85 constantTag initial_value_tag() const; // The tag will return true on one of is_int(), is_long(), is_single(), is_double()
86 jint int_initial_value() const;
87 jlong long_initial_value() const;
88 jfloat float_initial_value() const;
89 jdouble double_initial_value() const;
90 oop string_initial_value(TRAPS) const;
91
92 // Field signature type
93 BasicType field_type() const { return FieldType::basic_type(signature()); }
94
95 // Access flags
96 bool is_public() const { return access_flags().is_public(); }
97 bool is_private() const { return access_flags().is_private(); }
98 bool is_protected() const { return access_flags().is_protected(); }
99 bool is_package_private() const { return !is_public() && !is_private() && !is_protected(); }
100
101 bool is_static() const { return access_flags().is_static(); }
102 bool is_final() const { return access_flags().is_final(); }
103 bool is_volatile() const { return access_flags().is_volatile(); }
104 bool is_transient() const { return access_flags().is_transient(); }
105
106 bool is_synthetic() const { return access_flags().is_synthetic(); }
107
108 bool is_field_access_watched() const { return access_flags().is_field_access_watched(); }
109 bool is_field_modification_watched() const
110 { return access_flags().is_field_modification_watched(); }
111 bool has_initialized_final_update() const { return access_flags().has_field_initialized_final_update(); }
112 bool has_generic_signature() const { return access_flags().field_has_generic_signature(); }
113
114 void set_is_field_access_watched(const bool value) {
115 _access_flags.set_is_field_access_watched(value);
116 update_klass_field_access_flag();
117 }
118
119 void set_is_field_modification_watched(const bool value) {
120 _access_flags.set_is_field_modification_watched(value);
121 update_klass_field_access_flag();
122 }
123
124 void set_has_initialized_final_update(const bool value) {
125 _access_flags.set_has_field_initialized_final_update(value);
126 update_klass_field_access_flag();
127 }
128
129 // Initialization
130 void reinitialize(InstanceKlass* ik, int index);
131
132 // Print
133 void print() { print_on(tty); }
134 void print_on(outputStream* st) const PRODUCT_RETURN;
135 void print_on_for(outputStream* st, oop obj) PRODUCT_RETURN;
136 void verify() const PRODUCT_RETURN;
137 };
138
139 #endif // SHARE_VM_RUNTIME_FIELDDESCRIPTOR_HPP