001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 * 017 */ 018package org.apache.bcel.classfile; 019 020import java.io.ByteArrayInputStream; 021import java.io.DataInput; 022import java.io.DataOutputStream; 023import java.io.IOException; 024import java.nio.charset.StandardCharsets; 025 026import org.apache.bcel.Const; 027 028/** 029 * This class is derived from <em>Attribute</em> and represents a reference to a GJ attribute. 030 * 031 * @see Attribute 032 */ 033public final class Signature extends Attribute { 034 035 /** 036 * Extends ByteArrayInputStream to make 'unreading' chars possible. 037 */ 038 private static final class MyByteArrayInputStream extends ByteArrayInputStream { 039 040 MyByteArrayInputStream(final String data) { 041 super(data.getBytes(StandardCharsets.UTF_8)); 042 } 043 044 String getData() { 045 return new String(buf, StandardCharsets.UTF_8); 046 } 047 048 void unread() { 049 if (pos > 0) { 050 pos--; 051 } 052 } 053 } 054 055 private static boolean identStart(final int ch) { 056 return ch == 'T' || ch == 'L'; 057 } 058 059 // @since 6.0 is no longer final 060 public static boolean isActualParameterList(final String s) { 061 return s.startsWith("L") && s.endsWith(">;"); 062 } 063 064 // @since 6.0 is no longer final 065 public static boolean isFormalParameterList(final String s) { 066 return s.startsWith("<") && s.indexOf(':') > 0; 067 } 068 069 private static void matchGJIdent(final MyByteArrayInputStream in, final StringBuilder buf) { 070 int ch; 071 matchIdent(in, buf); 072 ch = in.read(); 073 if (ch == '<' || ch == '(') { // Parameterized or method 074 // System.out.println("Enter <"); 075 buf.append((char) ch); 076 matchGJIdent(in, buf); 077 while ((ch = in.read()) != '>' && ch != ')') { // List of parameters 078 if (ch == -1) { 079 throw new IllegalArgumentException("Illegal signature: " + in.getData() + " reaching EOF"); 080 } 081 // System.out.println("Still no >"); 082 buf.append(", "); 083 in.unread(); 084 matchGJIdent(in, buf); // Recursive call 085 } 086 // System.out.println("Exit >"); 087 buf.append((char) ch); 088 } else { 089 in.unread(); 090 } 091 ch = in.read(); 092 if (identStart(ch)) { 093 in.unread(); 094 matchGJIdent(in, buf); 095 } else if (ch == ')') { 096 in.unread(); 097 } else if (ch != ';') { 098 throw new IllegalArgumentException("Illegal signature: " + in.getData() + " read " + (char) ch); 099 } 100 } 101 102 private static void matchIdent(final MyByteArrayInputStream in, final StringBuilder buf) { 103 int ch; 104 if ((ch = in.read()) == -1) { 105 throw new IllegalArgumentException("Illegal signature: " + in.getData() + " no ident, reaching EOF"); 106 } 107 // System.out.println("return from ident:" + (char)ch); 108 if (!identStart(ch)) { 109 final StringBuilder buf2 = new StringBuilder(); 110 int count = 1; 111 while (Character.isJavaIdentifierPart((char) ch)) { 112 buf2.append((char) ch); 113 count++; 114 ch = in.read(); 115 } 116 if (ch == ':') { // Ok, formal parameter 117 final int skipExpected = "Ljava/lang/Object".length(); 118 final long skipActual = in.skip(skipExpected); 119 if (skipActual != skipExpected) { 120 throw new IllegalStateException(String.format("Unexpected skip: expected=%,d, actual=%,d", skipExpected, skipActual)); 121 } 122 buf.append(buf2); 123 ch = in.read(); 124 in.unread(); 125 // System.out.println("so far:" + buf2 + ":next:" +(char)ch); 126 } else { 127 for (int i = 0; i < count; i++) { 128 in.unread(); 129 } 130 } 131 return; 132 } 133 final StringBuilder buf2 = new StringBuilder(); 134 ch = in.read(); 135 do { 136 buf2.append((char) ch); 137 ch = in.read(); 138 // System.out.println("within ident:"+ (char)ch); 139 } while (ch != -1 && (Character.isJavaIdentifierPart((char) ch) || ch == '/')); 140 buf.append(Utility.pathToPackage(buf2.toString())); 141 // System.out.println("regular return ident:"+ (char)ch + ":" + buf2); 142 if (ch != -1) { 143 in.unread(); 144 } 145 } 146 147 public static String translate(final String s) { 148 // System.out.println("Sig:" + s); 149 final StringBuilder buf = new StringBuilder(); 150 matchGJIdent(new MyByteArrayInputStream(s), buf); 151 return buf.toString(); 152 } 153 154 private int signatureIndex; 155 156 /** 157 * Construct object from file stream. 158 * 159 * @param name_index Index in constant pool to CONSTANT_Utf8 160 * @param length Content length in bytes 161 * @param input Input stream 162 * @param constant_pool Array of constants 163 * @throws IOException if an I/O error occurs. 164 */ 165 Signature(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool) throws IOException { 166 this(name_index, length, input.readUnsignedShort(), constant_pool); 167 } 168 169 /** 170 * @param name_index Index in constant pool to CONSTANT_Utf8 171 * @param length Content length in bytes 172 * @param signatureIndex Index in constant pool to CONSTANT_Utf8 173 * @param constant_pool Array of constants 174 */ 175 public Signature(final int name_index, final int length, final int signatureIndex, final ConstantPool constant_pool) { 176 super(Const.ATTR_SIGNATURE, name_index, length, constant_pool); 177 this.signatureIndex = signatureIndex; 178 } 179 180 /** 181 * Initialize from another object. Note that both objects use the same references (shallow copy). Use clone() for a 182 * physical copy. 183 */ 184 public Signature(final Signature c) { 185 this(c.getNameIndex(), c.getLength(), c.getSignatureIndex(), c.getConstantPool()); 186 } 187 188 /** 189 * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. 190 * I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects. 191 * 192 * @param v Visitor object 193 */ 194 @Override 195 public void accept(final Visitor v) { 196 // System.err.println("Visiting non-standard Signature object"); 197 v.visitSignature(this); 198 } 199 200 /** 201 * @return deep copy of this attribute 202 */ 203 @Override 204 public Attribute copy(final ConstantPool constantPool) { 205 return (Attribute) clone(); 206 } 207 208 /** 209 * Dump source file attribute to file stream in binary format. 210 * 211 * @param file Output file stream 212 * @throws IOException if an I/O error occurs. 213 */ 214 @Override 215 public void dump(final DataOutputStream file) throws IOException { 216 super.dump(file); 217 file.writeShort(signatureIndex); 218 } 219 220 /** 221 * @return GJ signature. 222 */ 223 public String getSignature() { 224 return super.getConstantPool().getConstantUtf8(signatureIndex).getBytes(); 225 } 226 227 /** 228 * @return Index in constant pool of source file name. 229 */ 230 public int getSignatureIndex() { 231 return signatureIndex; 232 } 233 234 /** 235 * @param signatureIndex the index info the constant pool of this signature 236 */ 237 public void setSignatureIndex(final int signatureIndex) { 238 this.signatureIndex = signatureIndex; 239 } 240 241 /** 242 * @return String representation 243 */ 244 @Override 245 public String toString() { 246 final String s = getSignature(); 247 return "Signature: " + s; 248 } 249}