verificationType.cpp revision 3557:4ee06e614636 
1/*
2 * Copyright (c) 2003, 2012, 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.
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23 */
24
25#include "precompiled.hpp"
26#include "classfile/symbolTable.hpp"
27#include "classfile/verificationType.hpp"
28#include "classfile/verifier.hpp"
29
30VerificationType VerificationType::from_tag(u1 tag) {
31  switch (tag) {
32    case ITEM_Top:     return bogus_type();
33    case ITEM_Integer: return integer_type();
34    case ITEM_Float:   return float_type();
35    case ITEM_Double:  return double_type();
36    case ITEM_Long:    return long_type();
37    case ITEM_Null:    return null_type();
38    default:
39      ShouldNotReachHere();
40      return bogus_type();
41  }
42}
43
44bool VerificationType::is_reference_assignable_from(
45    const VerificationType& from, ClassVerifier* context, TRAPS) const {
46  instanceKlassHandle klass = context->current_class();
47  if (from.is_null()) {
48    // null is assignable to any reference
49    return true;
50  } else if (is_null()) {
51    return false;
52  } else if (name() == from.name()) {
53    return true;
54  } else if (is_object()) {
55    // We need check the class hierarchy to check assignability
56    if (name() == vmSymbols::java_lang_Object()) {
57      // any object or array is assignable to java.lang.Object
58      return true;
59    }
60    klassOop obj = SystemDictionary::resolve_or_fail(
61        name(), Handle(THREAD, klass->class_loader()),
62        Handle(THREAD, klass->protection_domain()), true, CHECK_false);
63    KlassHandle this_class(THREAD, obj);
64
65    if (this_class->is_interface()) {
66      // We treat interfaces as java.lang.Object, including
67      // java.lang.Cloneable and java.io.Serializable
68      return true;
69    } else if (from.is_object()) {
70      klassOop from_class = SystemDictionary::resolve_or_fail(
71          from.name(), Handle(THREAD, klass->class_loader()),
72          Handle(THREAD, klass->protection_domain()), true, CHECK_false);
73      return instanceKlass::cast(from_class)->is_subclass_of(this_class());
74    }
75  } else if (is_array() && from.is_array()) {
76    VerificationType comp_this = get_component(context, CHECK_false);
77    VerificationType comp_from = from.get_component(context, CHECK_false);
78    if (!comp_this.is_bogus() && !comp_from.is_bogus()) {
79      return comp_this.is_assignable_from(comp_from, context, CHECK_false);
80    }
81  }
82  return false;
83}
84
85VerificationType VerificationType::get_component(ClassVerifier *context, TRAPS) const {
86  assert(is_array() && name()->utf8_length() >= 2, "Must be a valid array");
87  Symbol* component;
88  switch (name()->byte_at(1)) {
89    case 'Z': return VerificationType(Boolean);
90    case 'B': return VerificationType(Byte);
91    case 'C': return VerificationType(Char);
92    case 'S': return VerificationType(Short);
93    case 'I': return VerificationType(Integer);
94    case 'J': return VerificationType(Long);
95    case 'F': return VerificationType(Float);
96    case 'D': return VerificationType(Double);
97    case '[':
98      component = context->create_temporary_symbol(
99        name(), 1, name()->utf8_length(),
100        CHECK_(VerificationType::bogus_type()));
101      return VerificationType::reference_type(component);
102    case 'L':
103      component = context->create_temporary_symbol(
104        name(), 2, name()->utf8_length() - 1,
105        CHECK_(VerificationType::bogus_type()));
106      return VerificationType::reference_type(component);
107    default:
108      // Met an invalid type signature, e.g. [X
109      return VerificationType::bogus_type();
110  }
111}
112
113void VerificationType::print_on(outputStream* st) const {
114  switch (_u._data) {
115    case Bogus:            st->print("top"); break;
116    case Category1:        st->print("category1"); break;
117    case Category2:        st->print("category2"); break;
118    case Category2_2nd:    st->print("category2_2nd"); break;
119    case Boolean:          st->print("boolean"); break;
120    case Byte:             st->print("byte"); break;
121    case Short:            st->print("short"); break;
122    case Char:             st->print("char"); break;
123    case Integer:          st->print("integer"); break;
124    case Float:            st->print("float"); break;
125    case Long:             st->print("long"); break;
126    case Double:           st->print("double"); break;
127    case Long_2nd:         st->print("long_2nd"); break;
128    case Double_2nd:       st->print("double_2nd"); break;
129    case Null:             st->print("null"); break;
130    case ReferenceQuery:   st->print("reference type"); break;
131    case Category1Query:   st->print("category1 type"); break;
132    case Category2Query:   st->print("category2 type"); break;
133    case Category2_2ndQuery: st->print("category2_2nd type"); break;
134    default:
135      if (is_uninitialized_this()) {
136        st->print("uninitializedThis");
137      } else if (is_uninitialized()) {
138        st->print("uninitialized %d", bci());
139      } else {
140        name()->print_value_on(st);
141      }
142  }
143}
144