serp.bytecode
Class StackInstruction

java.lang.Object
  serp.bytecode.Instruction
      serp.bytecode.TypedInstruction
          serp.bytecode.StackInstruction

All Implemented Interfaces:

BCEntity, VisitAcceptor

public class StackInstruction
extends TypedInstruction

Represents an instruction that manipulates the stack of the current frame. Using the setType(java.lang.String) methods is a hint about the type being manipulated that might cause this instruction to use the wide version of the opcode it represents (if manipulating a long or double). This saves the developer from having to decide at compile time whether to use pop or pop2, etc.

Author:

Abe White

Method Summary

void	acceptVisit(BCVisitor visit) Accept a visit from a BCVisitor, calling the appropriate methods to notify the visitor that it has entered this entity, and to provide it with the proper callbacks for each sub-entity owned by this one.
int	getStackChange() Return the number of stack positions this instruction pushes or pops during its execution.
String	getTypeName() This method will always return null; use isWide() to determine if this is pop2, dup2, etc.
boolean	isWide() Return whether to use the wide form of the current opcode for operations on longs or doubles.
TypedInstruction	setType(String type) Set the type of this instruction.
StackInstruction	setWide(boolean wide) Set whether to use the wide form of the current opcode for operations on longs or doubles.

Methods inherited from class serp.bytecode.TypedInstruction

getType, getTypeBC, setType, setType

Methods inherited from class serp.bytecode.Instruction

equalsInstruction, getByteIndex, getClassLoader, getCode, getLineNumber, getLogicalStackChange, getName, getOpcode, getPool, getProject, isValid

Methods inherited from class java.lang.Object

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

Method Detail

getStackChange

public int getStackChange()

Description copied from class: Instruction

Return the number of stack positions this instruction pushes or pops during its execution.

Overrides:

getStackChange in class Instruction

Returns:

0 if the stack is not affected by this instruction, a positive number if it pushes onto the stack, and a negative number if it pops from the stack

getTypeName

public String getTypeName()

This method will always return null; use isWide() to determine if this is pop2, dup2, etc.

Specified by:

getTypeName in class TypedInstruction

setType

public TypedInstruction setType(String type)

Description copied from class: TypedInstruction

Set the type of this instruction. Types that have no direct support will be converted accordingly.

Specified by:

setType in class TypedInstruction

Returns:

this instruction, for method chaining

isWide

public boolean isWide()

Return whether to use the wide form of the current opcode for operations on longs or doubles.

setWide

public StackInstruction setWide(boolean wide)

Set whether to use the wide form of the current opcode for operations on longs or doubles.

Returns:

this instruction, for method chaining

acceptVisit

public void acceptVisit(BCVisitor visit)

Description copied from interface: VisitAcceptor

Accept a visit from a BCVisitor, calling the appropriate methods to notify the visitor that it has entered this entity, and to provide it with the proper callbacks for each sub-entity owned by this one.

Specified by:

acceptVisit in interface VisitAcceptor

Overrides:

acceptVisit in class Instruction