1 /*
2 * Copyright (c) 2016, 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/ciField.hpp"
26 #include "ci/ciValueKlass.hpp"
27 #include "oops/fieldStreams.hpp"
28 #include "oops/valueKlass.hpp"
29
30 int ciValueKlass::compute_field_index_map() {
31 assert(is_loaded(), "value class must be loaded to compute mapping of field indeces");
32
33 if (_field_index_map != NULL) {
34 return _field_index_map->length();
35 }
36
37 Arena* arena = CURRENT_ENV->arena();
38 guarantee(has_nonstatic_fields(), "value types without fields currently not supported");
39
40 // FIXME: Once it is possible to construct class hierarchies with value types.
41 assert(!super()->has_nonstatic_fields(), "a value type must not inherit fields from its superclass");
42
43 _field_index_map = new (arena) GrowableArray<int>(arena, nof_declared_nonstatic_fields(), 0, 0);
44 GUARDED_VM_ENTRY(
45 valueKlassHandle vklass_h(ValueKlass::cast(get_Klass()));
46 methodHandle factory_h(vklass_h->factory_method());
47 if (factory_h.is_null()) { // Value parameter mapping not defined
48 for (JavaFieldStream fs(vklass_h); !fs.done(); fs.next()) {
49 if (fs.access_flags().is_static()) {
50 continue;
51 }
52 _field_index_map->append(fs.field_descriptor().index());
53 }
54 } else {
55 int valuefactory_length = factory_h->constMethod()->valuefactory_parameter_mapping_length();
56 assert(valuefactory_length == nof_declared_nonstatic_fields(),
57 "value factory length must be the same as the number of nonstatic declared for the value type");
58 for (int i = 0; i < nof_declared_nonstatic_fields(); i++) {
59 _field_index_map->append(factory_h->constMethod()->valuefactory_parameter_mapping_start()[i].data.field_index);
60 }
61 }
62 )
63 return _field_index_map->length();
64 }
65
66 // Number of value type fields
67 int ciValueKlass::field_count() {
68 if (_field_index_map == NULL) {
69 return compute_field_index_map();
70 } else {
71 return _field_index_map->length();
72 }
73 }
74
75 // Size of value type fields in words
76 int ciValueKlass::field_size() {
77 int size = 0;
78 for (int i = 0; i < field_count(); ++i) {
79 size += field_type_by_index(i)->size();
80 }
81 return size;
82 }
83
84 // Returns the index of the field with the given offset. If the field at 'offset'
85 // belongs to a flattened value type field, return the index of the field
86 // in the flattened value type.
87 int ciValueKlass::field_index_by_offset(int offset) {
88 assert(contains_field_offset(offset), "invalid field offset");
89 int best_offset = 0;
90 int best_index = -1;
91 // Search the field with the given offset
92 for (int i = 0; i < field_count(); ++i) {
93 int field_offset = field_offset_by_index(i);
94 if (field_offset == offset) {
95 // Exact match
96 return i;
97 } else if (field_offset < offset && field_offset > best_offset) {
98 // No exact match. Save the index of the field with the closest offset that
99 // is smaller than the given field offset. This index corresponds to the
100 // flattened value type field that holds the field we are looking for.
101 best_offset = field_offset;
102 best_index = i;
103 }
104 }
105 assert(best_index >= 0, "field not found");
106 assert(best_offset == offset || field_type_by_index(best_index)->is_valuetype(), "offset should match for non-VTs");
107 return best_index;
108 }
109
110 // Returns the field offset of the field with the given index
111 int ciValueKlass::field_offset_by_index(int index) {
112 if (_field_index_map == NULL) {
113 compute_field_index_map();
114 }
115 GUARDED_VM_ENTRY(
116 valueKlassHandle vklass_h(ValueKlass::cast(get_Klass()));
117 return vklass_h->field_offset(_field_index_map->at(index));
118 )
119 }
120
121 // Returns the field type of the field with the given index
122 ciType* ciValueKlass::field_type_by_index(int index) {
123 int offset = field_offset_by_index(index);
124 VM_ENTRY_MARK;
125 return get_field_type_by_offset(offset);
126 }
127
128 // Offset of the first field in the value type
129 int ciValueKlass::first_field_offset() const {
130 GUARDED_VM_ENTRY(
131 valueKlassHandle vklass_h(ValueKlass::cast(get_Klass()));
132 return vklass_h()->first_field_offset();
133 )
134 }