ciInstance.cpp revision 5776:de6a9e811145
1/*
2 * Copyright (c) 1999, 2013, 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
41ciType* 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
60//
61// Constant value of a field.
62ciConstant ciInstance::field_value(ciField* field) {
63  assert(is_loaded(), "invalid access - must be loaded");
64  assert(field->holder()->is_loaded(), "invalid access - holder must be loaded");
65  assert(klass()->is_subclass_of(field->holder()), "invalid access - must be subclass");
66
67  VM_ENTRY_MARK;
68  ciConstant result;
69  Handle obj = get_oop();
70  assert(!obj.is_null(), "bad oop");
71  BasicType field_btype = field->type()->basic_type();
72  int offset = field->offset();
73
74  switch(field_btype) {
75  case T_BYTE:
76    return ciConstant(field_btype, obj->byte_field(offset));
77    break;
78  case T_CHAR:
79    return ciConstant(field_btype, obj->char_field(offset));
80    break;
81  case T_SHORT:
82    return ciConstant(field_btype, obj->short_field(offset));
83    break;
84  case T_BOOLEAN:
85    return ciConstant(field_btype, obj->bool_field(offset));
86    break;
87  case T_INT:
88    return ciConstant(field_btype, obj->int_field(offset));
89    break;
90  case T_FLOAT:
91    return ciConstant(obj->float_field(offset));
92    break;
93  case T_DOUBLE:
94    return ciConstant(obj->double_field(offset));
95    break;
96  case T_LONG:
97    return ciConstant(obj->long_field(offset));
98    break;
99  case T_OBJECT:
100  case T_ARRAY:
101    {
102      oop o = obj->obj_field(offset);
103
104      // A field will be "constant" if it is known always to be
105      // a non-null reference to an instance of a particular class,
106      // or to a particular array.  This can happen even if the instance
107      // or array is not perm.  In such a case, an "unloaded" ciArray
108      // or ciInstance is created.  The compiler may be able to use
109      // information about the object's class (which is exact) or length.
110
111      if (o == NULL) {
112        return ciConstant(field_btype, ciNullObject::make());
113      } else {
114        return ciConstant(field_btype, CURRENT_ENV->get_object(o));
115      }
116    }
117  }
118  ShouldNotReachHere();
119  // to shut up the compiler
120  return ciConstant();
121}
122
123// ------------------------------------------------------------------
124// ciInstance::field_value_by_offset
125//
126// Constant value of a field at the specified offset.
127ciConstant ciInstance::field_value_by_offset(int field_offset) {
128  ciInstanceKlass* ik = klass()->as_instance_klass();
129  ciField* field = ik->get_field_by_offset(field_offset, false);
130  if (field == NULL)
131    return ciConstant();  // T_ILLEGAL
132  return field_value(field);
133}
134
135// ------------------------------------------------------------------
136// ciInstance::print_impl
137//
138// Implementation of the print method.
139void ciInstance::print_impl(outputStream* st) {
140  st->print(" type=");
141  klass()->print(st);
142}
143
144
145ciKlass* ciInstance::java_lang_Class_klass() {
146  VM_ENTRY_MARK;
147  return CURRENT_ENV->get_metadata(java_lang_Class::as_Klass(get_oop()))->as_klass();
148}
149