1 /*
2 * Copyright (c) 1999, 2017, 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/ciConstant.hpp"
27 #include "ci/ciField.hpp"
28 #include "ci/ciInstance.hpp"
29 #include "ci/ciInstanceKlass.hpp"
30 #include "ci/ciUtilities.hpp"
31 #include "classfile/systemDictionary.hpp"
32 #include "oops/oop.inline.hpp"
33
34 // ciInstance
35 //
36 // This class represents an instanceOop in the HotSpot virtual
37 // machine.
38
39 // ------------------------------------------------------------------
40 // ciObject::java_mirror_type
41 ciType* ciInstance::java_mirror_type() {
42 VM_ENTRY_MARK;
43 oop m = get_oop();
44 // Return NULL if it is not java.lang.Class.
45 if (m == NULL || m->klass() != SystemDictionary::Class_klass()) {
46 return NULL;
47 }
48 // Return either a primitive type or a klass.
49 if (java_lang_Class::is_primitive(m)) {
50 return ciType::make(java_lang_Class::primitive_type(m));
51 } else {
52 Klass* k = java_lang_Class::as_Klass(m);
53 assert(k != NULL, "");
54 return CURRENT_THREAD_ENV->get_klass(k);
55 }
56 }
57
58 // ------------------------------------------------------------------
59 // ciInstance::field_value_impl
60 ciConstant ciInstance::field_value_impl(BasicType field_btype, int offset) {
61 oop obj = get_oop();
62 assert(obj != NULL, "bad oop");
63 switch(field_btype) {
64 case T_BYTE: return ciConstant(field_btype, obj->byte_field(offset));
65 case T_CHAR: return ciConstant(field_btype, obj->char_field(offset));
66 case T_SHORT: return ciConstant(field_btype, obj->short_field(offset));
67 case T_BOOLEAN: return ciConstant(field_btype, obj->bool_field(offset));
68 case T_INT: return ciConstant(field_btype, obj->int_field(offset));
69 case T_FLOAT: return ciConstant(obj->float_field(offset));
70 case T_DOUBLE: return ciConstant(obj->double_field(offset));
71 case T_LONG: return ciConstant(obj->long_field(offset));
72 case T_OBJECT: // fall through
73 case T_ARRAY: {
74 oop o = obj->obj_field(offset);
75
76 // A field will be "constant" if it is known always to be
77 // a non-null reference to an instance of a particular class,
78 // or to a particular array. This can happen even if the instance
79 // or array is not perm. In such a case, an "unloaded" ciArray
80 // or ciInstance is created. The compiler may be able to use
81 // information about the object's class (which is exact) or length.
82
83 if (o == NULL) {
84 return ciConstant(field_btype, ciNullObject::make());
85 } else {
86 return ciConstant(field_btype, CURRENT_ENV->get_object(o));
87 }
88 }
89 default:
90 fatal("no field value: %s", type2name(field_btype));
91 return ciConstant();
92 }
93 }
94
95 // ------------------------------------------------------------------
96 // ciInstance::field_value
97 //
98 // Constant value of a field.
99 ciConstant ciInstance::field_value(ciField* field) {
100 assert(is_loaded(), "invalid access - must be loaded");
101 assert(field->holder()->is_loaded(), "invalid access - holder must be loaded");
102 assert(field->is_static() || klass()->is_subclass_of(field->holder()), "invalid access - must be subclass");
103
104 GUARDED_VM_ENTRY(return field_value_impl(field->type()->basic_type(), field->offset());)
105 }
106
107 // ------------------------------------------------------------------
108 // ciInstance::field_value_by_offset
109 //
110 // Constant value of a field at the specified offset.
111 ciConstant ciInstance::field_value_by_offset(int field_offset) {
112 ciInstanceKlass* ik = klass()->as_instance_klass();
113 ciField* field = ik->get_field_by_offset(field_offset, false);
114 if (field == NULL)
115 return ciConstant(); // T_ILLEGAL
116 return field_value(field);
117 }
118
119 // ------------------------------------------------------------------
120 // ciInstance::print_impl
121 //
122 // Implementation of the print method.
123 void ciInstance::print_impl(outputStream* st) {
124 st->print(" type=");
125 klass()->print(st);
126 }
127
128
129 ciKlass* ciInstance::java_lang_Class_klass() {
130 VM_ENTRY_MARK;
131 return CURRENT_ENV->get_metadata(java_lang_Class::as_Klass(get_oop()))->as_klass();
132 }