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25 
26 package sun.invoke.util;
27 
28 import java.lang.invoke.MethodType;
29 import java.util.ArrayList;
30 import java.util.List;
31 
32 /**
33  * Utility routines for dealing with bytecode-level signatures.
34  * @author jrose
35  */
36 public class BytecodeDescriptor {
37 
BytecodeDescriptor()38     private BytecodeDescriptor() { }  // cannot instantiate
39 
parseMethod(String bytecodeSignature, ClassLoader loader)40     public static List<Class<?>> parseMethod(String bytecodeSignature, ClassLoader loader) {
41         return parseMethod(bytecodeSignature, 0, bytecodeSignature.length(), loader);
42     }
43 
parseMethod(String bytecodeSignature, int start, int end, ClassLoader loader)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 
parseError(String str, String msg)70     static private void parseError(String str, String msg) {
71         throw new IllegalArgumentException("bad signature: "+str+": "+msg);
72     }
73 
parseSig(String str, int[] i, int end, ClassLoader loader)74     static private 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 
unparse(Class<?> type)97     public static String unparse(Class<?> type) {
98         StringBuilder sb = new StringBuilder();
99         unparseSig(type, sb);
100         return sb.toString();
101     }
102 
unparse(MethodType type)103     public static String unparse(MethodType type) {
104         return unparseMethod(type.returnType(), type.parameterList());
105     }
106 
unparse(Object type)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 
unparseMethod(Class<?> rtype, List<Class<?>> ptypes)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 
unparseSig(Class<?> t, StringBuilder sb)125     static private 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