leola.vm

Class ExceptionStack

java.lang.Object

leola.vm.ExceptionStack

public class ExceptionStack
extends Object

Keeps track of the program counters for jumping during try/catch/finally blocks.

This keeps an internal Stack of the INIT_*_BLOCKS which contain a program counter to the jumping END_BLOCK instruction set (which depending on the type will execute a CATCH or FINALLY block statements).

Author:

Tony

Constructor Summary

Constructors

Constructor and Description
ExceptionStack()

Method Summary

Modifier and Type	Method and Description
boolean	isEmpty()
int	peekAddress()
boolean	peekIsCatch()
boolean	peekIsFinally()
void	pop() Removes the top of the Stack
void	pushCatch(int pc) Push a Try block with a Catch statement on to the stack
void	pushFinally(int pc) Push a Try block with a Finally statement on to the stack

Methods inherited from class java.lang.Object

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

Constructor Detail

ExceptionStack

public ExceptionStack()

Method Detail

isEmpty

public boolean isEmpty()

Returns:

true if there are currently no try statements pushed on to the stack.

pushFinally

public void pushFinally(int pc)

Push a Try block with a Finally statement on to the stack

Parameters:

pc - the program counter (instruction index) to jump to

pushCatch

public void pushCatch(int pc)

Push a Try block with a Catch statement on to the stack

Parameters:

pc - the program counter (instruction index) to jump to

peekIsFinally

public boolean peekIsFinally()

Returns:

peek at the top of the stack to see if there is a Finally block to be executed

peekIsCatch

public boolean peekIsCatch()

Returns:

peek at the top of the stack to see if there is a Catch block to be executed

peekAddress

public int peekAddress()

Returns:

the program counter at the top of the stack

pop

public void pop()

Removes the top of the Stack