1 /* 2 * Copyright (C) 2006 Google Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.inject.internal.util; 18 19 import static com.google.common.base.Preconditions.checkNotNull; 20 21 import com.google.common.base.Preconditions; 22 import com.google.common.collect.Maps; 23 import java.io.IOException; 24 import java.io.InputStream; 25 import java.lang.reflect.Constructor; 26 import java.lang.reflect.Field; 27 import java.lang.reflect.Member; 28 import java.lang.reflect.Method; 29 import java.util.Map; 30 import org.objectweb.asm.AnnotationVisitor; 31 import org.objectweb.asm.ClassReader; 32 import org.objectweb.asm.ClassVisitor; 33 import org.objectweb.asm.FieldVisitor; 34 import org.objectweb.asm.Label; 35 import org.objectweb.asm.MethodVisitor; 36 import org.objectweb.asm.Opcodes; 37 38 /** 39 * Looks up line numbers for classes and their members. 40 * 41 * @author Chris Nokleberg 42 */ 43 final class LineNumbers { 44 45 private final Class type; 46 private final Map<String, Integer> lines = Maps.newHashMap(); 47 private String source; 48 private int firstLine = Integer.MAX_VALUE; 49 50 /** 51 * Reads line number information from the given class, if available. 52 * 53 * @param type the class to read line number information from 54 * @throws IllegalArgumentException if the bytecode for the class cannot be found 55 * @throws java.io.IOException if an error occurs while reading bytecode 56 */ 57 public LineNumbers(Class type) throws IOException { 58 this.type = type; 59 60 if (!type.isArray()) { 61 InputStream in = type.getResourceAsStream("/" + type.getName().replace('.', '/') + ".class"); 62 if (in != null) { 63 try { 64 new ClassReader(in).accept(new LineNumberReader(), ClassReader.SKIP_FRAMES); 65 } finally { 66 try { 67 in.close(); 68 } catch (IOException ignored) { 69 } 70 } 71 } 72 } 73 } 74 75 /** 76 * Get the source file name as read from the bytecode. 77 * 78 * @return the source file name if available, or null 79 */ 80 public String getSource() { 81 return source; 82 } 83 84 /** 85 * Get the line number associated with the given member. 86 * 87 * @param member a field, constructor, or method belonging to the class used during construction 88 * @return the wrapped line number, or null if not available 89 * @throws IllegalArgumentException if the member does not belong to the class used during 90 * construction 91 */ 92 public Integer getLineNumber(Member member) { 93 Preconditions.checkArgument( 94 type == member.getDeclaringClass(), 95 "Member %s belongs to %s, not %s", 96 member, 97 member.getDeclaringClass(), 98 type); 99 return lines.get(memberKey(member)); 100 } 101 102 /** Gets the first line number. */ 103 public int getFirstLine() { 104 return firstLine == Integer.MAX_VALUE ? 1 : firstLine; 105 } 106 107 private String memberKey(Member member) { 108 checkNotNull(member, "member"); 109 110 /*if[AOP]*/ 111 if (member instanceof Field) { 112 return member.getName(); 113 114 } else if (member instanceof Method) { 115 return member.getName() + org.objectweb.asm.Type.getMethodDescriptor((Method) member); 116 117 } else if (member instanceof Constructor) { 118 StringBuilder sb = new StringBuilder().append("<init>("); 119 for (Class param : ((Constructor) member).getParameterTypes()) { 120 sb.append(org.objectweb.asm.Type.getDescriptor(param)); 121 } 122 return sb.append(")V").toString(); 123 124 } else { 125 throw new IllegalArgumentException( 126 "Unsupported implementation class for Member, " + member.getClass()); 127 } 128 /*end[AOP]*/ 129 /*if[NO_AOP] 130 return "<NO_MEMBER_KEY>"; 131 end[NO_AOP]*/ 132 } 133 134 private class LineNumberReader extends ClassVisitor { 135 136 private int line = -1; 137 private String pendingMethod; 138 private String name; 139 140 LineNumberReader() { 141 super(Opcodes.ASM6); 142 } 143 144 @Override 145 public void visit( 146 int version, 147 int access, 148 String name, 149 String signature, 150 String superName, 151 String[] interfaces) { 152 this.name = name; 153 } 154 155 @Override 156 public MethodVisitor visitMethod( 157 int access, String name, String desc, String signature, String[] exceptions) { 158 if ((access & Opcodes.ACC_PRIVATE) != 0) { 159 return null; 160 } 161 pendingMethod = name + desc; 162 line = -1; 163 return new LineNumberMethodVisitor(); 164 } 165 166 @Override 167 public void visitSource(String source, String debug) { 168 LineNumbers.this.source = source; 169 } 170 171 public void visitLineNumber(int line, Label start) { 172 if (line < firstLine) { 173 firstLine = line; 174 } 175 176 this.line = line; 177 if (pendingMethod != null) { 178 lines.put(pendingMethod, line); 179 pendingMethod = null; 180 } 181 } 182 183 @Override 184 public FieldVisitor visitField( 185 int access, String name, String desc, String signature, Object value) { 186 return null; 187 } 188 189 @Override 190 public AnnotationVisitor visitAnnotation(String desc, boolean visible) { 191 return new LineNumberAnnotationVisitor(); 192 } 193 194 public AnnotationVisitor visitParameterAnnotation(int parameter, String desc, boolean visible) { 195 return new LineNumberAnnotationVisitor(); 196 } 197 198 class LineNumberMethodVisitor extends MethodVisitor { 199 LineNumberMethodVisitor() { 200 super(Opcodes.ASM6); 201 } 202 203 @Override 204 public AnnotationVisitor visitAnnotation(String desc, boolean visible) { 205 return new LineNumberAnnotationVisitor(); 206 } 207 208 @Override 209 public AnnotationVisitor visitAnnotationDefault() { 210 return new LineNumberAnnotationVisitor(); 211 } 212 213 @Override 214 public void visitFieldInsn(int opcode, String owner, String name, String desc) { 215 if (opcode == Opcodes.PUTFIELD 216 && LineNumberReader.this.name.equals(owner) 217 && !lines.containsKey(name) 218 && line != -1) { 219 lines.put(name, line); 220 } 221 } 222 223 @Override 224 public void visitLineNumber(int line, Label start) { 225 LineNumberReader.this.visitLineNumber(line, start); 226 } 227 } 228 229 class LineNumberAnnotationVisitor extends AnnotationVisitor { 230 LineNumberAnnotationVisitor() { 231 super(Opcodes.ASM6); 232 } 233 234 @Override 235 public AnnotationVisitor visitAnnotation(String name, String desc) { 236 return this; 237 } 238 239 @Override 240 public AnnotationVisitor visitArray(String name) { 241 return this; 242 } 243 244 public void visitLocalVariable( 245 String name, String desc, String signature, Label start, Label end, int index) {} 246 } 247 } 248 } 249