BytecodeDescriptor.java revision 12745:f068a4ffddd2 
1/*
2 * Copyright (c) 2008, 2011, 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.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package sun.invoke.util;
27
28import java.lang.invoke.MethodType;
29import java.util.ArrayList;
30import java.util.List;
31
32/**
33 * Utility routines for dealing with bytecode-level signatures.
34 * @author jrose
35 */
36public class BytecodeDescriptor {
37
38    private BytecodeDescriptor() { }  // cannot instantiate
39
40    public static List<Class<?>> parseMethod(String bytecodeSignature, ClassLoader loader) {
41        return parseMethod(bytecodeSignature, 0, bytecodeSignature.length(), loader);
42    }
43
44    static List<Class<?>> parseMethod(String bytecodeSignature,
45            int start, int end, ClassLoader loader) {
46        if (loader == null)
47            loader = ClassLoader.getSystemClassLoader();
48        String str = bytecodeSignature;
49        int[] i = {start};
50        ArrayList<Class<?>> ptypes = new ArrayList<Class<?>>();
51        if (i[0] < end && str.charAt(i[0]) == '(') {
52            ++i[0];  // skip '('
53            while (i[0] < end && str.charAt(i[0]) != ')') {
54                Class<?> pt = parseSig(str, i, end, loader);
55                if (pt == null || pt == void.class)
56                    parseError(str, "bad argument type");
57                ptypes.add(pt);
58            }
59            ++i[0];  // skip ')'
60        } else {
61            parseError(str, "not a method type");
62        }
63        Class<?> rtype = parseSig(str, i, end, loader);
64        if (rtype == null || i[0] != end)
65            parseError(str, "bad return type");
66        ptypes.add(rtype);
67        return ptypes;
68    }
69
70    private static void parseError(String str, String msg) {
71        throw new IllegalArgumentException("bad signature: "+str+": "+msg);
72    }
73
74    private static Class<?> parseSig(String str, int[] i, int end, ClassLoader loader) {
75        if (i[0] == end)  return null;
76        char c = str.charAt(i[0]++);
77        if (c == 'L') {
78            int begc = i[0], endc = str.indexOf(';', begc);
79            if (endc < 0)  return null;
80            i[0] = endc+1;
81            String name = str.substring(begc, endc).replace('/', '.');
82            try {
83                return loader.loadClass(name);
84            } catch (ClassNotFoundException ex) {
85                throw new TypeNotPresentException(name, ex);
86            }
87        } else if (c == '[') {
88            Class<?> t = parseSig(str, i, end, loader);
89            if (t != null)
90                t = java.lang.reflect.Array.newInstance(t, 0).getClass();
91            return t;
92        } else {
93            return Wrapper.forBasicType(c).primitiveType();
94        }
95    }
96
97    public static String unparse(Class<?> type) {
98        StringBuilder sb = new StringBuilder();
99        unparseSig(type, sb);
100        return sb.toString();
101    }
102
103    public static String unparse(MethodType type) {
104        return unparseMethod(type.returnType(), type.parameterList());
105    }
106
107    public static String unparse(Object type) {
108        if (type instanceof Class<?>)
109            return unparse((Class<?>) type);
110        if (type instanceof MethodType)
111            return unparse((MethodType) type);
112        return (String) type;
113    }
114
115    public static String unparseMethod(Class<?> rtype, List<Class<?>> ptypes) {
116        StringBuilder sb = new StringBuilder();
117        sb.append('(');
118        for (Class<?> pt : ptypes)
119            unparseSig(pt, sb);
120        sb.append(')');
121        unparseSig(rtype, sb);
122        return sb.toString();
123    }
124
125    private static void unparseSig(Class<?> t, StringBuilder sb) {
126        char c = Wrapper.forBasicType(t).basicTypeChar();
127        if (c != 'L') {
128            sb.append(c);
129        } else {
130            boolean lsemi = (!t.isArray());
131            if (lsemi)  sb.append('L');
132            sb.append(t.getName().replace('.', '/'));
133            if (lsemi)  sb.append(';');
134        }
135    }
136
137}
138