1 /*
2 * Copyright (c) 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 package jdk.experimental.bytecode;
25
26 import java.util.Iterator;
27
28 /**
29 * Helper to create and manipulate type descriptors, where type descriptors
30 * are represented as JVM type descriptor strings and symbols are represented
31 * as name strings
32 */
33 public class BasicTypeHelper implements TypeHelper<String, String> {
34
35 @Override
36 public String elemtype(String s) {
37 if (!s.startsWith("[")) {
38 throw new IllegalStateException();
39 }
40 return s.substring(1);
41 }
42
43 @Override
44 public String arrayOf(String s) {
45 return "[" + s;
46 }
47
48 @Override
49 public String type(String s) {
50 return "L" + s + ";";
51 }
52
53
54 @Override
55 public TypeTag tag(String s) {
56 switch (s.charAt(0)) {
57 case '[':
58 case 'L':
59 return TypeTag.A;
60 case 'B':
61 case 'C':
62 case 'Z':
63 case 'S':
64 case 'I':
65 return TypeTag.I;
66 case 'F':
67 return TypeTag.F;
68 case 'J':
69 return TypeTag.J;
70 case 'D':
71 return TypeTag.D;
72 case 'V':
73 return TypeTag.V;
74 default:
75 if (s == nullType()) {
76 return TypeTag.A;
77 }
78 throw new IllegalStateException("Bad type: " + s);
79 }
80 }
81
82 @Override
83 public String nullType() {
84 // Needed in TypedCodeBuilder; ACONST_NULL pushes a 'null' onto the stack,
85 // and stack maps handle null differently
86 return "<null>";
87 }
88
89 @Override
90 public String commonSupertype(String t1, String t2) {
91 if (t1.equals(t2)) {
92 return t1;
93 } else {
94 try {
95 Class<?> c1 = from(t1);
96 Class<?> c2 = from(t2);
97 if (c1.isAssignableFrom(c2)) {
98 return t1;
99 } else if (c2.isAssignableFrom(c1)) {
100 return t2;
101 } else {
102 return "Ljava/lang/Object;";
103 }
104 } catch (Exception e) {
105 return null;
106 }
107 }
108 }
109
110 public Class<?> from(String desc) throws ReflectiveOperationException {
111 if (desc.startsWith("[")) {
112 return Class.forName(desc.replaceAll("/", "."));
113 } else {
114 return Class.forName(symbol(desc).replaceAll("/", "."));
115 }
116 }
117
118 @Override
119 public Iterator<String> parameterTypes(String s) {
120 //TODO: gracefully non-method types
121 return new Iterator<String>() {
122 int ch = 1;
123
124 @Override
125 public boolean hasNext() {
126 return s.charAt(ch) != ')';
127 }
128
129 @Override
130 public String next() {
131 char curr = s.charAt(ch);
132 switch (curr) {
133 case 'C':
134 case 'B':
135 case 'S':
136 case 'I':
137 case 'J':
138 case 'F':
139 case 'D':
140 case 'Z':
141 ch++;
142 return String.valueOf(curr);
143 case '[':
144 ch++;
145 return "[" + next();
146 case 'L':
147 StringBuilder builder = new StringBuilder();
148 while (curr != ';') {
149 builder.append(curr);
150 curr = s.charAt(++ch);
151 }
152 builder.append(';');
153 ch++;
154 return builder.toString();
155 default:
156 throw new AssertionError("cannot parse string: " + s);
157 }
158 }
159 };
160 }
161
162 @Override
163 public String symbolFrom(String s) {
164 return s;
165 }
166
167 @Override
168 public String fromTag(TypeTag tag) {
169 return tag.name();
170 }
171
172 @Override
173 public String symbol(String type) {
174 return (type.startsWith("L") || type.startsWith("Q")) ? type.substring(1, type.length() - 1) : type;
175 }
176
177 @Override
178 public String returnType(String s) {
179 return s.substring(s.indexOf(')') + 1, s.length());
180 }
181
182 }