Package org.hotswap.agent.javassist.bytecode.stackmap

Class Tracer

java.lang.Object

org.hotswap.agent.javassist.bytecode.stackmap.Tracer

All Implemented Interfaces:

TypeTag

Direct Known Subclasses:

MapMaker

public abstract class Tracer
extends Object
implements TypeTag

Field Summary

Fields

Modifier and Type	Field	Description
protected ClassPool	classPool
protected ConstPool	cpool
protected TypeData[]	localsTypes
protected String	returnType
protected int	stackTop
protected TypeData[]	stackTypes

Fields inherited from interface org.hotswap.agent.javassist.bytecode.stackmap.TypeTag

DOUBLE, FLOAT, INTEGER, LONG, TOP, TOP_TYPE

Constructor Summary

Constructors

Constructor	Description
Tracer(Tracer t)
Tracer(ClassPool classes, ConstPool cp, int maxStack, int maxLocals, String retType)

Method Summary

Modifier and Type	Method	Description
protected int	doOpcode(int pos, byte[] code)	Does abstract interpretation on the given bytecode instruction.
protected void	visitBranch(int pos, byte[] code, int offset)
protected void	visitGoto(int pos, byte[] code, int offset)
protected void	visitJSR(int pos, byte[] code)	Invoked when the visited instruction is jsr.
protected void	visitLookupSwitch(int pos, byte[] code, int n, int pairsPos, int defaultOffset)
protected void	visitRET(int pos, byte[] code)	Invoked when the visited instruction is ret or wide ret.
protected void	visitReturn(int pos, byte[] code)
protected void	visitTableSwitch(int pos, byte[] code, int n, int offsetPos, int defaultOffset)
protected void	visitThrow(int pos, byte[] code)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

classPool

protected ClassPool classPool

cpool

protected ConstPool cpool

returnType

protected String returnType

stackTop

protected int stackTop

stackTypes

protected TypeData[] stackTypes

localsTypes

protected TypeData[] localsTypes

Constructor Detail

Tracer

public Tracer(ClassPool classes,
              ConstPool cp,
              int maxStack,
              int maxLocals,
              String retType)

Tracer

public Tracer(Tracer t)

Method Detail

doOpcode

protected int doOpcode(int pos,
                       byte[] code)
                throws BadBytecode

Does abstract interpretation on the given bytecode instruction. It records whether or not a local variable (i.e. register) is accessed. If the instruction requires that a local variable or a stack element has a more specific type, this method updates the type of it.

Parameters:

pos - the position of the instruction.

Returns:

the size of the instruction at POS.

Throws:

BadBytecode

visitBranch

protected void visitBranch(int pos,
                           byte[] code,
                           int offset)
                    throws BadBytecode

Throws:

BadBytecode

visitGoto

protected void visitGoto(int pos,
                         byte[] code,
                         int offset)
                  throws BadBytecode

Throws:

BadBytecode

visitReturn

protected void visitReturn(int pos,
                           byte[] code)
                    throws BadBytecode

Throws:

BadBytecode

visitThrow

protected void visitThrow(int pos,
                          byte[] code)
                   throws BadBytecode

Throws:

BadBytecode

visitTableSwitch

protected void visitTableSwitch(int pos,
                                byte[] code,
                                int n,
                                int offsetPos,
                                int defaultOffset)
                         throws BadBytecode

Parameters:

pos - the position of TABLESWITCH

code - bytecode

n - the number of case labels

offsetPos - the position of the branch-target table.

defaultOffset - the offset to the default branch target.

Throws:

BadBytecode

visitLookupSwitch

protected void visitLookupSwitch(int pos,
                                 byte[] code,
                                 int n,
                                 int pairsPos,
                                 int defaultOffset)
                          throws BadBytecode

Parameters:

pos - the position of LOOKUPSWITCH

code - bytecode

n - the number of case labels

pairsPos - the position of the table of pairs of a value and a branch target.

defaultOffset - the offset to the default branch target.

Throws:

BadBytecode

visitJSR

protected void visitJSR(int pos,
                        byte[] code)
                 throws BadBytecode

Invoked when the visited instruction is jsr. Java6 or later does not allow using RET.

Throws:

BadBytecode

visitRET

protected void visitRET(int pos,
                        byte[] code)
                 throws BadBytecode

Invoked when the visited instruction is ret or wide ret. Java6 or later does not allow using RET.

Throws:

BadBytecode