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

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