1/*
2 * Copyright (c) 2003, 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 "precompiled.hpp"
26#include "classfile/symbolTable.hpp"
27#include "classfile/systemDictionaryShared.hpp"
28#include "classfile/verificationType.hpp"
29#include "classfile/verifier.hpp"
30
31VerificationType VerificationType::from_tag(u1 tag) {
32  switch (tag) {
33    case ITEM_Top:     return bogus_type();
34    case ITEM_Integer: return integer_type();
35    case ITEM_Float:   return float_type();
36    case ITEM_Double:  return double_type();
37    case ITEM_Long:    return long_type();
38    case ITEM_Null:    return null_type();
39    default:
40      ShouldNotReachHere();
41      return bogus_type();
42  }
43}
44
45bool VerificationType::resolve_and_check_assignability(instanceKlassHandle klass, Symbol* name,
46         Symbol* from_name, bool from_field_is_protected, bool from_is_array, bool from_is_object, TRAPS) {
47  Klass* obj = SystemDictionary::resolve_or_fail(
48      name, Handle(THREAD, klass->class_loader()),
49      Handle(THREAD, klass->protection_domain()), true, CHECK_false);
50  if (log_is_enabled(Debug, class, resolve)) {
51    Verifier::trace_class_resolution(obj, klass());
52  }
53
54  KlassHandle this_class(THREAD, obj);
55
56  if (this_class->is_interface() && (!from_field_is_protected ||
57      from_name != vmSymbols::java_lang_Object())) {
58    // If we are not trying to access a protected field or method in
59    // java.lang.Object then, for arrays, we only allow assignability
60    // to interfaces java.lang.Cloneable and java.io.Serializable.
61    // Otherwise, we treat interfaces as java.lang.Object.
62    return !from_is_array ||
63      this_class == SystemDictionary::Cloneable_klass() ||
64      this_class == SystemDictionary::Serializable_klass();
65  } else if (from_is_object) {
66    Klass* from_class = SystemDictionary::resolve_or_fail(
67        from_name, Handle(THREAD, klass->class_loader()),
68        Handle(THREAD, klass->protection_domain()), true, CHECK_false);
69    if (log_is_enabled(Debug, class, resolve)) {
70      Verifier::trace_class_resolution(from_class, klass());
71    }
72    return InstanceKlass::cast(from_class)->is_subclass_of(this_class());
73  }
74
75  return false;
76}
77
78bool VerificationType::is_reference_assignable_from(
79    const VerificationType& from, ClassVerifier* context,
80    bool from_field_is_protected, TRAPS) const {
81  instanceKlassHandle klass = context->current_class();
82  if (from.is_null()) {
83    // null is assignable to any reference
84    return true;
85  } else if (is_null()) {
86    return false;
87  } else if (name() == from.name()) {
88    return true;
89  } else if (is_object()) {
90    // We need check the class hierarchy to check assignability
91    if (name() == vmSymbols::java_lang_Object()) {
92      // any object or array is assignable to java.lang.Object
93      return true;
94    }
95
96    if (DumpSharedSpaces && SystemDictionaryShared::add_verification_constraint(klass(),
97              name(), from.name(), from_field_is_protected, from.is_array(),
98              from.is_object())) {
99      // If add_verification_constraint() returns true, the resolution/check should be
100      // delayed until runtime.
101      return true;
102    }
103
104    return resolve_and_check_assignability(klass(), name(), from.name(),
105          from_field_is_protected, from.is_array(), from.is_object(), THREAD);
106  } else if (is_array() && from.is_array()) {
107    VerificationType comp_this = get_component(context, CHECK_false);
108    VerificationType comp_from = from.get_component(context, CHECK_false);
109    if (!comp_this.is_bogus() && !comp_from.is_bogus()) {
110      return comp_this.is_component_assignable_from(comp_from, context,
111                                          from_field_is_protected, CHECK_false);
112    }
113  }
114  return false;
115}
116
117VerificationType VerificationType::get_component(ClassVerifier *context, TRAPS) const {
118  assert(is_array() && name()->utf8_length() >= 2, "Must be a valid array");
119  Symbol* component;
120  switch (name()->byte_at(1)) {
121    case 'Z': return VerificationType(Boolean);
122    case 'B': return VerificationType(Byte);
123    case 'C': return VerificationType(Char);
124    case 'S': return VerificationType(Short);
125    case 'I': return VerificationType(Integer);
126    case 'J': return VerificationType(Long);
127    case 'F': return VerificationType(Float);
128    case 'D': return VerificationType(Double);
129    case '[':
130      component = context->create_temporary_symbol(
131        name(), 1, name()->utf8_length(),
132        CHECK_(VerificationType::bogus_type()));
133      return VerificationType::reference_type(component);
134    case 'L':
135      component = context->create_temporary_symbol(
136        name(), 2, name()->utf8_length() - 1,
137        CHECK_(VerificationType::bogus_type()));
138      return VerificationType::reference_type(component);
139    default:
140      // Met an invalid type signature, e.g. [X
141      return VerificationType::bogus_type();
142  }
143}
144
145void VerificationType::print_on(outputStream* st) const {
146  switch (_u._data) {
147    case Bogus:            st->print("top"); break;
148    case Category1:        st->print("category1"); break;
149    case Category2:        st->print("category2"); break;
150    case Category2_2nd:    st->print("category2_2nd"); break;
151    case Boolean:          st->print("boolean"); break;
152    case Byte:             st->print("byte"); break;
153    case Short:            st->print("short"); break;
154    case Char:             st->print("char"); break;
155    case Integer:          st->print("integer"); break;
156    case Float:            st->print("float"); break;
157    case Long:             st->print("long"); break;
158    case Double:           st->print("double"); break;
159    case Long_2nd:         st->print("long_2nd"); break;
160    case Double_2nd:       st->print("double_2nd"); break;
161    case Null:             st->print("null"); break;
162    case ReferenceQuery:   st->print("reference type"); break;
163    case Category1Query:   st->print("category1 type"); break;
164    case Category2Query:   st->print("category2 type"); break;
165    case Category2_2ndQuery: st->print("category2_2nd type"); break;
166    default:
167      if (is_uninitialized_this()) {
168        st->print("uninitializedThis");
169      } else if (is_uninitialized()) {
170        st->print("uninitialized %d", bci());
171      } else {
172        name()->print_value_on(st);
173      }
174  }
175}
176