org.objectweb.asm.commons
Class EmptyVisitor

java.lang.Object
  extended by org.objectweb.asm.commons.EmptyVisitor
All Implemented Interfaces:
AnnotationVisitor, ClassVisitor, FieldVisitor, MethodVisitor

public class EmptyVisitor
extends Object
implements ClassVisitor, FieldVisitor, MethodVisitor, AnnotationVisitor

An empty implementation of the ASM visitor interfaces.

Author:
Eric Bruneton

Constructor Summary
EmptyVisitor()
           
 
Method Summary
 void visit(int version, int access, String name, String signature, String superName, String[] interfaces)
          Visits the header of the class.
 void visit(String name, Object value)
          Visits a primitive value of the annotation.
 AnnotationVisitor visitAnnotation(String desc, boolean visible)
          Visits an annotation of the class.
 AnnotationVisitor visitAnnotation(String name, String desc)
          Visits a nested annotation value of the annotation.
 AnnotationVisitor visitAnnotationDefault()
          Visits the default value of this annotation interface method.
 AnnotationVisitor visitArray(String name)
          Visits an array value of the annotation.
 void visitAttribute(Attribute attr)
          Visits a non standard attribute of the class.
 void visitCode()
          Starts the visit of the method's code, if any (i.e. non abstract method).
 void visitEnd()
          Visits the end of the class.
 void visitEnum(String name, String desc, String value)
          Visits an enumeration value of the annotation.
 FieldVisitor visitField(int access, String name, String desc, String signature, Object value)
          Visits a field of the class.
 void visitFieldInsn(int opcode, String owner, String name, String desc)
          Visits a field instruction.
 void visitFrame(int type, int nLocal, Object[] local, int nStack, Object[] stack)
          Visits the current state of the local variables and operand stack elements.
 void visitIincInsn(int var, int increment)
          Visits an IINC instruction.
 void visitInnerClass(String name, String outerName, String innerName, int access)
          Visits information about an inner class.
 void visitInsn(int opcode)
          Visits a zero operand instruction.
 void visitIntInsn(int opcode, int operand)
          Visits an instruction with a single int operand.
 void visitJumpInsn(int opcode, Label label)
          Visits a jump instruction.
 void visitLabel(Label label)
          Visits a label.
 void visitLdcInsn(Object cst)
          Visits a LDC instruction.
 void visitLineNumber(int line, Label start)
          Visits a line number declaration.
 void visitLocalVariable(String name, String desc, String signature, Label start, Label end, int index)
          Visits a local variable declaration.
 void visitLookupSwitchInsn(Label dflt, int[] keys, Label[] labels)
          Visits a LOOKUPSWITCH instruction.
 void visitMaxs(int maxStack, int maxLocals)
          Visits the maximum stack size and the maximum number of local variables of the method.
 MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions)
          Visits a method of the class.
 void visitMethodInsn(int opcode, String owner, String name, String desc)
          Visits a method instruction.
 void visitMultiANewArrayInsn(String desc, int dims)
          Visits a MULTIANEWARRAY instruction.
 void visitOuterClass(String owner, String name, String desc)
          Visits the enclosing class of the class.
 AnnotationVisitor visitParameterAnnotation(int parameter, String desc, boolean visible)
          Visits an annotation of a parameter this method.
 void visitSource(String source, String debug)
          Visits the source of the class.
 void visitTableSwitchInsn(int min, int max, Label dflt, Label[] labels)
          Visits a TABLESWITCH instruction.
 void visitTryCatchBlock(Label start, Label end, Label handler, String type)
          Visits a try catch block.
 void visitTypeInsn(int opcode, String type)
          Visits a type instruction.
 void visitVarInsn(int opcode, int var)
          Visits a local variable instruction.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

EmptyVisitor

public EmptyVisitor()
Method Detail

visit

public void visit(int version,
                  int access,
                  String name,
                  String signature,
                  String superName,
                  String[] interfaces)
Description copied from interface: ClassVisitor
Visits the header of the class.

Specified by:
visit in interface ClassVisitor
Parameters:
version - the class version.
access - the class's access flags (see Opcodes). This parameter also indicates if the class is deprecated.
name - the internal name of the class (see getInternalName).
signature - the signature of this class. May be null if the class is not a generic one, and does not extend or implement generic classes or interfaces.
superName - the internal of name of the super class (see getInternalName). For interfaces, the super class is Object. May be null, but only for the Object class.
interfaces - the internal names of the class's interfaces (see getInternalName). May be null.

visitSource

public void visitSource(String source,
                        String debug)
Description copied from interface: ClassVisitor
Visits the source of the class.

Specified by:
visitSource in interface ClassVisitor
Parameters:
source - the name of the source file from which the class was compiled. May be null.
debug - additional debug information to compute the correspondance between source and compiled elements of the class. May be null.

visitOuterClass

public void visitOuterClass(String owner,
                            String name,
                            String desc)
Description copied from interface: ClassVisitor
Visits the enclosing class of the class. This method must be called only if the class has an enclosing class.

Specified by:
visitOuterClass in interface ClassVisitor
Parameters:
owner - internal name of the enclosing class of the class.
name - the name of the method that contains the class, or null if the class is not enclosed in a method of its enclosing class.
desc - the descriptor of the method that contains the class, or null if the class is not enclosed in a method of its enclosing class.

visitAnnotation

public AnnotationVisitor visitAnnotation(String desc,
                                         boolean visible)
Description copied from interface: ClassVisitor
Visits an annotation of the class.

Specified by:
visitAnnotation in interface ClassVisitor
Specified by:
visitAnnotation in interface FieldVisitor
Specified by:
visitAnnotation in interface MethodVisitor
Parameters:
desc - the class descriptor of the annotation class.
visible - true if the annotation is visible at runtime.
Returns:
a visitor to visit the annotation values, or null if this visitor is not interested in visiting this annotation.

visitAttribute

public void visitAttribute(Attribute attr)
Description copied from interface: ClassVisitor
Visits a non standard attribute of the class.

Specified by:
visitAttribute in interface ClassVisitor
Specified by:
visitAttribute in interface FieldVisitor
Specified by:
visitAttribute in interface MethodVisitor
Parameters:
attr - an attribute.

visitInnerClass

public void visitInnerClass(String name,
                            String outerName,
                            String innerName,
                            int access)
Description copied from interface: ClassVisitor
Visits information about an inner class. This inner class is not necessarily a member of the class being visited.

Specified by:
visitInnerClass in interface ClassVisitor
Parameters:
name - the internal name of an inner class (see getInternalName).
outerName - the internal name of the class to which the inner class belongs (see getInternalName). May be null for not member classes.
innerName - the (simple) name of the inner class inside its enclosing class. May be null for anonymous inner classes.
access - the access flags of the inner class as originally declared in the enclosing class.

visitField

public FieldVisitor visitField(int access,
                               String name,
                               String desc,
                               String signature,
                               Object value)
Description copied from interface: ClassVisitor
Visits a field of the class.

Specified by:
visitField in interface ClassVisitor
Parameters:
access - the field's access flags (see Opcodes). This parameter also indicates if the field is synthetic and/or deprecated.
name - the field's name.
desc - the field's descriptor (see Type).
signature - the field's signature. May be null if the field's type does not use generic types.
value - the field's initial value. This parameter, which may be null if the field does not have an initial value, must be an Integer, a Float, a Long, a Double or a String (for int, float, long or String fields respectively). This parameter is only used for static fields. Its value is ignored for non static fields, which must be initialized through bytecode instructions in constructors or methods.
Returns:
a visitor to visit field annotations and attributes, or null if this class visitor is not interested in visiting these annotations and attributes.

visitMethod

public MethodVisitor visitMethod(int access,
                                 String name,
                                 String desc,
                                 String signature,
                                 String[] exceptions)
Description copied from interface: ClassVisitor
Visits a method of the class. This method must return a new MethodVisitor instance (or null) each time it is called, i.e., it should not return a previously returned visitor.

Specified by:
visitMethod in interface ClassVisitor
Parameters:
access - the method's access flags (see Opcodes). This parameter also indicates if the method is synthetic and/or deprecated.
name - the method's name.
desc - the method's descriptor (see Type).
signature - the method's signature. May be null if the method parameters, return type and exceptions do not use generic types.
exceptions - the internal names of the method's exception classes (see getInternalName). May be null.
Returns:
an object to visit the byte code of the method, or null if this class visitor is not interested in visiting the code of this method.

visitEnd

public void visitEnd()
Description copied from interface: ClassVisitor
Visits the end of the class. This method, which is the last one to be called, is used to inform the visitor that all the fields and methods of the class have been visited.

Specified by:
visitEnd in interface AnnotationVisitor
Specified by:
visitEnd in interface ClassVisitor
Specified by:
visitEnd in interface FieldVisitor
Specified by:
visitEnd in interface MethodVisitor

visitAnnotationDefault

public AnnotationVisitor visitAnnotationDefault()
Description copied from interface: MethodVisitor
Visits the default value of this annotation interface method.

Specified by:
visitAnnotationDefault in interface MethodVisitor
Returns:
a visitor to the visit the actual default value of this annotation interface method, or null if this visitor is not interested in visiting this default value. The 'name' parameters passed to the methods of this annotation visitor are ignored. Moreover, exacly one visit method must be called on this annotation visitor, followed by visitEnd.

visitParameterAnnotation

public AnnotationVisitor visitParameterAnnotation(int parameter,
                                                  String desc,
                                                  boolean visible)
Description copied from interface: MethodVisitor
Visits an annotation of a parameter this method.

Specified by:
visitParameterAnnotation in interface MethodVisitor
Parameters:
parameter - the parameter index.
desc - the class descriptor of the annotation class.
visible - true if the annotation is visible at runtime.
Returns:
a visitor to visit the annotation values, or null if this visitor is not interested in visiting this annotation.

visitCode

public void visitCode()
Description copied from interface: MethodVisitor
Starts the visit of the method's code, if any (i.e. non abstract method).

Specified by:
visitCode in interface MethodVisitor

visitFrame

public void visitFrame(int type,
                       int nLocal,
                       Object[] local,
                       int nStack,
                       Object[] stack)
Description copied from interface: MethodVisitor
Visits the current state of the local variables and operand stack elements. This method must(*) be called just before any instruction i that follows an unconditional branch instruction such as GOTO or THROW, that is the target of a jump instruction, or that starts an exception handler block. The visited types must describe the values of the local variables and of the operand stack elements just before i is executed.

(*) this is mandatory only for classes whose version is greater than or equal to V1_6.

Packed frames are basically "deltas" from the state of the previous frame (very first frame is implicitly defined by the method's parameters and access flags):

Specified by:
visitFrame in interface MethodVisitor
Parameters:
type - the type of this stack map frame. Must be Opcodes.F_NEW for expanded frames, or Opcodes.F_FULL, Opcodes.F_APPEND, Opcodes.F_CHOP, Opcodes.F_SAME or Opcodes.F_APPEND, Opcodes.F_SAME1 for compressed frames.
nLocal - the number of local variables in the visited frame.
local - the local variable types in this frame. This array must not be modified. Primitive types are represented by Opcodes.TOP, Opcodes.INTEGER, Opcodes.FLOAT, Opcodes.LONG, Opcodes.DOUBLE,Opcodes.NULL or Opcodes.UNINITIALIZED_THIS (long and double are represented by a single element). Reference types are represented by String objects (representing internal names), and uninitialized types by Label objects (this label designates the NEW instruction that created this uninitialized value).
nStack - the number of operand stack elements in the visited frame.
stack - the operand stack types in this frame. This array must not be modified. Its content has the same format as the "local" array.

visitInsn

public void visitInsn(int opcode)
Description copied from interface: MethodVisitor
Visits a zero operand instruction.

Specified by:
visitInsn in interface MethodVisitor
Parameters:
opcode - the opcode of the instruction to be visited. This opcode is either NOP, ACONST_NULL, ICONST_M1, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4, ICONST_5, LCONST_0, LCONST_1, FCONST_0, FCONST_1, FCONST_2, DCONST_0, DCONST_1, IALOAD, LALOAD, FALOAD, DALOAD, AALOAD, BALOAD, CALOAD, SALOAD, IASTORE, LASTORE, FASTORE, DASTORE, AASTORE, BASTORE, CASTORE, SASTORE, POP, POP2, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, SWAP, IADD, LADD, FADD, DADD, ISUB, LSUB, FSUB, DSUB, IMUL, LMUL, FMUL, DMUL, IDIV, LDIV, FDIV, DDIV, IREM, LREM, FREM, DREM, INEG, LNEG, FNEG, DNEG, ISHL, LSHL, ISHR, LSHR, IUSHR, LUSHR, IAND, LAND, IOR, LOR, IXOR, LXOR, I2L, I2F, I2D, L2I, L2F, L2D, F2I, F2L, F2D, D2I, D2L, D2F, I2B, I2C, I2S, LCMP, FCMPL, FCMPG, DCMPL, DCMPG, IRETURN, LRETURN, FRETURN, DRETURN, ARETURN, RETURN, ARRAYLENGTH, ATHROW, MONITORENTER, or MONITOREXIT.

visitIntInsn

public void visitIntInsn(int opcode,
                         int operand)
Description copied from interface: MethodVisitor
Visits an instruction with a single int operand.

Specified by:
visitIntInsn in interface MethodVisitor
Parameters:
opcode - the opcode of the instruction to be visited. This opcode is either BIPUSH, SIPUSH or NEWARRAY.
operand - the operand of the instruction to be visited.
When opcode is BIPUSH, operand value should be between Byte.MIN_VALUE and Byte.MAX_VALUE.
When opcode is SIPUSH, operand value should be between Short.MIN_VALUE and Short.MAX_VALUE.
When opcode is NEWARRAY, operand value should be one of Opcodes.T_BOOLEAN, Opcodes.T_CHAR, Opcodes.T_FLOAT, Opcodes.T_DOUBLE, Opcodes.T_BYTE, Opcodes.T_SHORT, Opcodes.T_INT or Opcodes.T_LONG.

visitVarInsn

public void visitVarInsn(int opcode,
                         int var)
Description copied from interface: MethodVisitor
Visits a local variable instruction. A local variable instruction is an instruction that loads or stores the value of a local variable.

Specified by:
visitVarInsn in interface MethodVisitor
Parameters:
opcode - the opcode of the local variable instruction to be visited. This opcode is either ILOAD, LLOAD, FLOAD, DLOAD, ALOAD, ISTORE, LSTORE, FSTORE, DSTORE, ASTORE or RET.
var - the operand of the instruction to be visited. This operand is the index of a local variable.

visitTypeInsn

public void visitTypeInsn(int opcode,
                          String type)
Description copied from interface: MethodVisitor
Visits a type instruction. A type instruction is an instruction that takes the internal name of a class as parameter.

Specified by:
visitTypeInsn in interface MethodVisitor
Parameters:
opcode - the opcode of the type instruction to be visited. This opcode is either NEW, ANEWARRAY, CHECKCAST or INSTANCEOF.
type - the operand of the instruction to be visited. This operand must be the internal name of an object or array class (see getInternalName).

visitFieldInsn

public void visitFieldInsn(int opcode,
                           String owner,
                           String name,
                           String desc)
Description copied from interface: MethodVisitor
Visits a field instruction. A field instruction is an instruction that loads or stores the value of a field of an object.

Specified by:
visitFieldInsn in interface MethodVisitor
Parameters:
opcode - the opcode of the type instruction to be visited. This opcode is either GETSTATIC, PUTSTATIC, GETFIELD or PUTFIELD.
owner - the internal name of the field's owner class (see getInternalName).
name - the field's name.
desc - the field's descriptor (see Type).

visitMethodInsn

public void visitMethodInsn(int opcode,
                            String owner,
                            String name,
                            String desc)
Description copied from interface: MethodVisitor
Visits a method instruction. A method instruction is an instruction that invokes a method.

Specified by:
visitMethodInsn in interface MethodVisitor
Parameters:
opcode - the opcode of the type instruction to be visited. This opcode is either INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC, INVOKEINTERFACE or INVOKEDYNAMIC.
owner - the internal name of the method's owner class (see getInternalName) or Opcodes.INVOKEDYNAMIC_OWNER.
name - the method's name.
desc - the method's descriptor (see Type).

visitJumpInsn

public void visitJumpInsn(int opcode,
                          Label label)
Description copied from interface: MethodVisitor
Visits a jump instruction. A jump instruction is an instruction that may jump to another instruction.

Specified by:
visitJumpInsn in interface MethodVisitor
Parameters:
opcode - the opcode of the type instruction to be visited. This opcode is either IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE, IF_ICMPEQ, IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ACMPEQ, IF_ACMPNE, GOTO, JSR, IFNULL or IFNONNULL.
label - the operand of the instruction to be visited. This operand is a label that designates the instruction to which the jump instruction may jump.

visitLabel

public void visitLabel(Label label)
Description copied from interface: MethodVisitor
Visits a label. A label designates the instruction that will be visited just after it.

Specified by:
visitLabel in interface MethodVisitor
Parameters:
label - a Label object.

visitLdcInsn

public void visitLdcInsn(Object cst)
Description copied from interface: MethodVisitor
Visits a LDC instruction.

Specified by:
visitLdcInsn in interface MethodVisitor
Parameters:
cst - the constant to be loaded on the stack. This parameter must be a non null Integer, a Float, a Long, a Double a String (or a Type for .class constants, for classes whose version is 49.0 or more).

visitIincInsn

public void visitIincInsn(int var,
                          int increment)
Description copied from interface: MethodVisitor
Visits an IINC instruction.

Specified by:
visitIincInsn in interface MethodVisitor
Parameters:
var - index of the local variable to be incremented.
increment - amount to increment the local variable by.

visitTableSwitchInsn

public void visitTableSwitchInsn(int min,
                                 int max,
                                 Label dflt,
                                 Label[] labels)
Description copied from interface: MethodVisitor
Visits a TABLESWITCH instruction.

Specified by:
visitTableSwitchInsn in interface MethodVisitor
Parameters:
min - the minimum key value.
max - the maximum key value.
dflt - beginning of the default handler block.
labels - beginnings of the handler blocks. labels[i] is the beginning of the handler block for the min + i key.

visitLookupSwitchInsn

public void visitLookupSwitchInsn(Label dflt,
                                  int[] keys,
                                  Label[] labels)
Description copied from interface: MethodVisitor
Visits a LOOKUPSWITCH instruction.

Specified by:
visitLookupSwitchInsn in interface MethodVisitor
Parameters:
dflt - beginning of the default handler block.
keys - the values of the keys.
labels - beginnings of the handler blocks. labels[i] is the beginning of the handler block for the keys[i] key.

visitMultiANewArrayInsn

public void visitMultiANewArrayInsn(String desc,
                                    int dims)
Description copied from interface: MethodVisitor
Visits a MULTIANEWARRAY instruction.

Specified by:
visitMultiANewArrayInsn in interface MethodVisitor
Parameters:
desc - an array type descriptor (see Type).
dims - number of dimensions of the array to allocate.

visitTryCatchBlock

public void visitTryCatchBlock(Label start,
                               Label end,
                               Label handler,
                               String type)
Description copied from interface: MethodVisitor
Visits a try catch block.

Specified by:
visitTryCatchBlock in interface MethodVisitor
Parameters:
start - beginning of the exception handler's scope (inclusive).
end - end of the exception handler's scope (exclusive).
handler - beginning of the exception handler's code.
type - internal name of the type of exceptions handled by the handler, or null to catch any exceptions (for "finally" blocks).

visitLocalVariable

public void visitLocalVariable(String name,
                               String desc,
                               String signature,
                               Label start,
                               Label end,
                               int index)
Description copied from interface: MethodVisitor
Visits a local variable declaration.

Specified by:
visitLocalVariable in interface MethodVisitor
Parameters:
name - the name of a local variable.
desc - the type descriptor of this local variable.
signature - the type signature of this local variable. May be null if the local variable type does not use generic types.
start - the first instruction corresponding to the scope of this local variable (inclusive).
end - the last instruction corresponding to the scope of this local variable (exclusive).
index - the local variable's index.

visitLineNumber

public void visitLineNumber(int line,
                            Label start)
Description copied from interface: MethodVisitor
Visits a line number declaration.

Specified by:
visitLineNumber in interface MethodVisitor
Parameters:
line - a line number. This number refers to the source file from which the class was compiled.
start - the first instruction corresponding to this line number.

visitMaxs

public void visitMaxs(int maxStack,
                      int maxLocals)
Description copied from interface: MethodVisitor
Visits the maximum stack size and the maximum number of local variables of the method.

Specified by:
visitMaxs in interface MethodVisitor
Parameters:
maxStack - maximum stack size of the method.
maxLocals - maximum number of local variables for the method.

visit

public void visit(String name,
                  Object value)
Description copied from interface: AnnotationVisitor
Visits a primitive value of the annotation.

Specified by:
visit in interface AnnotationVisitor
Parameters:
name - the value name.
value - the actual value, whose type must be Byte, Boolean, Character, Short, Integer, Long, Float, Double, String or Type. This value can also be an array of byte, boolean, short, char, int, long, float or double values (this is equivalent to using visitArray and visiting each array element in turn, but is more convenient).

visitEnum

public void visitEnum(String name,
                      String desc,
                      String value)
Description copied from interface: AnnotationVisitor
Visits an enumeration value of the annotation.

Specified by:
visitEnum in interface AnnotationVisitor
Parameters:
name - the value name.
desc - the class descriptor of the enumeration class.
value - the actual enumeration value.

visitAnnotation

public AnnotationVisitor visitAnnotation(String name,
                                         String desc)
Description copied from interface: AnnotationVisitor
Visits a nested annotation value of the annotation.

Specified by:
visitAnnotation in interface AnnotationVisitor
Parameters:
name - the value name.
desc - the class descriptor of the nested annotation class.
Returns:
a visitor to visit the actual nested annotation value, or null if this visitor is not interested in visiting this nested annotation. The nested annotation value must be fully visited before calling other methods on this annotation visitor.

visitArray

public AnnotationVisitor visitArray(String name)
Description copied from interface: AnnotationVisitor
Visits an array value of the annotation. Note that arrays of primitive types (such as byte, boolean, short, char, int, long, float or double) can be passed as value to visit. This is what ClassReader does.

Specified by:
visitArray in interface AnnotationVisitor
Parameters:
name - the value name.
Returns:
a visitor to visit the actual array value elements, or null if this visitor is not interested in visiting these values. The 'name' parameters passed to the methods of this visitor are ignored. All the array values must be visited before calling other methods on this annotation visitor.