net.sf.jode.flow
Class CreateIfThenElseOperator

java.lang.Object
  net.sf.jode.flow.CreateIfThenElseOperator

public class CreateIfThenElseOperator

extends java.lang.Object

Constructor Summary

CreateIfThenElseOperator()

Method Summary

static boolean	create(InstructionContainer ic, StructuredBlock last) This handles the normal form of the ?
static boolean	createFunny(ConditionalBlock cb, StructuredBlock last) This handles the more complicated form of the ?

Methods inherited from class java.lang.Object

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

Constructor Detail

CreateIfThenElseOperator

public CreateIfThenElseOperator()

Method Detail

createFunny

public static boolean createFunny(ConditionalBlock cb,
                                  StructuredBlock last)

This handles the more complicated form of the ?-:-operator used in a conditional block. The simplest case is:

   if (cond)
       PUSH e1
   else {
       IF (c2)
           GOTO flow_2_
       PUSH false
   }
 ->IF (stack_0 == 0)
     GOTO flow_1_
   GOTO flow_2_
 

is transformed to

   push cond ? e1 : c2
 ->IF (stack_0 == 0)
     GOTO flow_1_
   GOTO flow_2_
 

The -> points to the lastModified block. Note that both the if and the then part may contain this condition+push0-block. There may be even stack if-then-else-blocks for very complicated nested ?-:-Operators.

Also note that the produced code is suboptimal: The push-0 could sometimes be better replaced with a correct jump.

create

public static boolean create(InstructionContainer ic,
                             StructuredBlock last)

This handles the normal form of the ?-:-operator:

   if (cond)
       push e1
       GOTO flow_1_
 ->push e2
   GOTO flow_2
 

is transformed to

 ->push cond ? e1 : e2
 

The -> points to the lastModified block.