net.sf.jode.flow
Class IfThenElseBlock

java.lang.Object
  net.sf.jode.flow.StructuredBlock
      net.sf.jode.flow.IfThenElseBlock

public class IfThenElseBlock
extends StructuredBlock

An IfThenElseBlock is the structured block representing an if instruction. The else part may be null.

Constructor Summary

IfThenElseBlock(Expression cond)
Creates a new if then else block.

Method Summary

boolean	doTransformations() Do simple transformation on the structuredBlock.
void	dumpInstruction(TabbedPrintWriter writer) Print the source code for this structured block.
Expression	getCondition() Gets the condition.
Set	getDeclarables()
StructuredBlock	getElseBlock()
StructuredBlock[]	getSubBlocks() Returns all sub block of this structured block.
StructuredBlock	getThenBlock()
boolean	hasElse()
boolean	jumpMayBeChanged() Determines if there is a sub block, that flows through to the end of this block.
void	makeDeclaration(Set done) Make the declarations, i.e.
VariableStack	mapStackToLocal(VariableStack stack) This does take the instr into account and modifies stack accordingly.
void	removePush() This is called after mapStackToLocal to do the stack to local transformation.
boolean	replaceSubBlock(StructuredBlock oldBlock, StructuredBlock newBlock) Replaces the given sub block with a new block.
void	setElseBlock(StructuredBlock elseBlock) Sets the else block.
void	setThenBlock(StructuredBlock thenBlock) Sets the then block.
void	simplify()

Methods inherited from class net.sf.jode.flow.StructuredBlock

appendBlock, checkConsistent, contains, copyJump, dumpSource, fillInGenSet, flowMayBeChanged, getBCELInstructions, getBytecodeInstructions, getNextBlock, getNextBlock, getNextFlowBlock, getNextFlowBlock, isEmpty, isSingleExit, moveJump, needsBraces, prependBlock, propagateUsage, removeBlock, removeJump, removeOnetimeLocals, replace, setFlowBlock, setJump, setSuccessors, swapJump, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

IfThenElseBlock

public IfThenElseBlock(Expression cond)

Creates a new if then else block. The method setThenBlock must be called shortly after the creation.

Method Detail

getCondition

public Expression getCondition()

Gets the condition. The expression returned has boolean type.

setThenBlock

public void setThenBlock(StructuredBlock thenBlock)

Sets the then block.

Parameters:

thenBlock - the then block, must be non null.

getThenBlock

public StructuredBlock getThenBlock()

setElseBlock

public void setElseBlock(StructuredBlock elseBlock)

Sets the else block.

Parameters:

elseBlock - the else block

getElseBlock

public StructuredBlock getElseBlock()

hasElse

public boolean hasElse()

replaceSubBlock

public boolean replaceSubBlock(StructuredBlock oldBlock,
                               StructuredBlock newBlock)

Replaces the given sub block with a new block.

Overrides:

replaceSubBlock in class StructuredBlock

Parameters:

oldBlock - the old sub block.

newBlock - the new sub block.

Returns:

false, if oldBlock wasn't a direct sub block.

mapStackToLocal

public VariableStack mapStackToLocal(VariableStack stack)

This does take the instr into account and modifies stack accordingly. It then calls super.mapStackToLocal.

Overrides:

mapStackToLocal in class StructuredBlock

Parameters:

stack - the stack before the instruction is called

Returns:

stack the stack afterwards.

removePush

public void removePush()

Description copied from class: StructuredBlock

This is called after mapStackToLocal to do the stack to local transformation.

Overrides:

removePush in class StructuredBlock

getDeclarables

public Set getDeclarables()

Overrides:

getDeclarables in class StructuredBlock

makeDeclaration

public void makeDeclaration(Set done)

Make the declarations, i.e. initialize the declare variable to correct values. This will declare every variable that is marked as used, but not done.
This will now also combine locals, that use the same slot, have compatible types and are declared in the same block.

Overrides:

makeDeclaration in class StructuredBlock

Parameters:

done - The set of the already declare variables.

dumpInstruction

public void dumpInstruction(TabbedPrintWriter writer)
                     throws IOException

Print the source code for this structured block. This may be called only once, because it remembers which local variables were declared.

Specified by:

dumpInstruction in class StructuredBlock

Parameters:

writer - The tabbed print writer, where we print to.

Throws:

IOException

getSubBlocks

public StructuredBlock[] getSubBlocks()

Returns all sub block of this structured block.

Overrides:

getSubBlocks in class StructuredBlock

jumpMayBeChanged

public boolean jumpMayBeChanged()

Determines if there is a sub block, that flows through to the end of this block. If this returns true, you know that jump is null.

Overrides:

jumpMayBeChanged in class StructuredBlock

Returns:

true, if the jump may be safely changed.

simplify

public void simplify()

Overrides:

simplify in class StructuredBlock

doTransformations

public boolean doTransformations()

Description copied from class: StructuredBlock

Do simple transformation on the structuredBlock.

Overrides:

doTransformations in class StructuredBlock

Returns:

true, if some transformation was done.