src/main/java/jp/sourceforge/stigmata/birthmarks/cvfv/ConstantValueOfFieldVariableBirthmarkExtractVisitor.java

   1 package jp.sourceforge.stigmata.birthmarks.cvfv;
   2
   3 /*
   4  * $Id$
   5  */
   6
   7 import java.util.LinkedHashMap;
   8 import java.util.Map;
   9
  10 import jp.sourceforge.stigmata.Birthmark;
  11 import jp.sourceforge.stigmata.BirthmarkContext;
  12 import jp.sourceforge.stigmata.birthmarks.BirthmarkExtractVisitor;
  13
  14 import org.objectweb.asm.ClassVisitor;
  15 import org.objectweb.asm.FieldVisitor;
  16 import org.objectweb.asm.MethodAdapter;
  17 import org.objectweb.asm.MethodVisitor;
  18 import org.objectweb.asm.Opcodes;
  19 import org.objectweb.asm.Type;
  20
  21 /**
  22  *
  23  *
  24  *
  25  * @author Haruaki TAMADA
  26  * @version $Revision$
  27  */
  28 public class ConstantValueOfFieldVariableBirthmarkExtractVisitor extends BirthmarkExtractVisitor{
  29     private Map<String, TypeAndValueBirthmarkElement> elements = new LinkedHashMap<String, TypeAndValueBirthmarkElement>();
  30     private String className;
  31
  32     public ConstantValueOfFieldVariableBirthmarkExtractVisitor(ClassVisitor visitor, Birthmark birthmark, BirthmarkContext context){
  33         super(visitor, birthmark, context);
  34     }
  35
  36     @Override
  37     public void visitEnd(){
  38         for(String key: elements.keySet()){
  39             addElement(elements.get(key));
  40         }
  41         super.visitEnd();
  42     }
  43
  44     @Override
  45     public void visit(int version, int access, String name, String signature,
  46                       String superName, String[] interfaces){
  47         this.className = name;
  48
  49         super.visit(version, access, name, signature, superName, interfaces);
  50     }
  51
  52     @Override
  53     public FieldVisitor visitField(int access, String name, String desc,
  54                                    String signature, Object value){
  55
  56         FieldVisitor visitor = super.visitField(access, name, desc, signature, value);
  57
  58         TypeAndValueBirthmarkElement e = elements.get(name);
  59         if(e == null){
  60             e = new TypeAndValueBirthmarkElement(desc, value);
  61         }
  62         else{
  63             if(value != null){
  64                 e.setValue(value);
  65             }
  66         }
  67         elements.put(name, e);
  68
  69         return visitor;
  70     }
  71
  72     @Override
  73     public MethodVisitor visitMethod(int access, String name, String desc, String signature,
  74                                      String[] exceptions){
  75         MethodVisitor visitor = super.visitMethod(access, name, desc, signature, exceptions);
  76
  77         if(name.equals("<init>") || name.equals("<clinit>")){
  78             visitor = new MethodAdapter(visitor){
  79                 private Object constant = null;
  80
  81                 @Override
  82                 public void visitIntInsn(int opcode, int operand){
  83                     if(opcode == Opcodes.BIPUSH || opcode == Opcodes.SIPUSH){
  84                         constant = new Integer(operand);
  85                     }
  86                     super.visitIntInsn(opcode, operand);
  87                 }
  88
  89                 @Override
  90                 public void visitMethodInsn(int opcode, String owner, String name, String desc){
  91                     Type type = Type.getReturnType(desc);
  92                     if(!type.equals(Type.VOID_TYPE)){
  93                         constant = null;
  94                     }
  95                     super.visitMethodInsn(opcode, owner, name, desc);
  96                 }
  97
  98                 @Override
  99                 public void visitInsn(int opcode){
 100                     if(opcode == Opcodes.ICONST_M1)     constant = new Integer(-1);
 101                     else if(opcode == Opcodes.ICONST_0) constant = new Integer(0);
 102                     else if(opcode == Opcodes.ICONST_1) constant = new Integer(1);
 103                     else if(opcode == Opcodes.ICONST_2) constant = new Integer(2);
 104                     else if(opcode == Opcodes.ICONST_3) constant = new Integer(3);
 105                     else if(opcode == Opcodes.ICONST_4) constant = new Integer(4);
 106                     else if(opcode == Opcodes.ICONST_5) constant = new Integer(5);
 107                     else if(opcode == Opcodes.LCONST_0) constant = new Long(0L);
 108                     else if(opcode == Opcodes.LCONST_1) constant = new Long(1L);
 109                     else if(opcode == Opcodes.DCONST_0) constant = new Double(0D);
 110                     else if(opcode == Opcodes.DCONST_1) constant = new Double(1D);
 111                     else if(opcode == Opcodes.FCONST_0) constant = new Float(0F);
 112                     else if(opcode == Opcodes.FCONST_1) constant = new Float(1F);
 113                     else if(opcode == Opcodes.FCONST_2) constant = new Float(2F);
 114
 115                     super.visitInsn(opcode);
 116                 }
 117
 118                 @Override
 119                 public void visitLdcInsn(Object object){
 120                     constant = object;
 121                     super.visitLdcInsn(object);
 122                 }
 123
 124                 @Override
 125                 public void visitFieldInsn(int opcode, String owner, String name, String desc){
 126                     if(className.equals(owner) && opcode == Opcodes.PUTFIELD){
 127                         TypeAndValueBirthmarkElement e = elements.get(name);
 128                         if(e == null){
 129                             e = new TypeAndValueBirthmarkElement(desc, constant);
 130                         }
 131
 132                         if(e.getValue() == null && constant != null){
 133                             if(!checkCast(desc, constant)){
 134                                 constant = null;
 135                             }
 136                             e.setValue(constant);
 137                         }
 138                     }
 139                     super.visitFieldInsn(opcode, owner, name, desc);
 140                 }
 141             };
 142         }
 143
 144         return visitor;
 145     }
 146
 147     private boolean checkCast(String desc, Object constant){
 148         if(constant instanceof Integer){
 149             return desc.equals("Ljava/lang/Integer;") ||
 150                 desc.equals("I") || desc.equals("S") || desc.equals("Z") ||
 151                 desc.equals("C") || desc.equals("B");
 152         }
 153         else if(constant instanceof Float){
 154             return desc.equals("Ljava/lang/Float;") || desc.equals("F");
 155         }
 156         else if(constant instanceof Double){
 157             return desc.equals("Ljava/lang/Double;") || desc.equals("D");
 158         }
 159         else if(constant instanceof Long){
 160             return desc.equals("Ljava/lang/Long;") || desc.equals("J");
 161         }
 162         else if(constant instanceof String){
 163             return desc.equals("Ljava/lang/String;");
 164         }
 165         return false;
 166     }
 167 }