Package org.apache.bcel.verifier.structurals

Interface InstructionContext

public interface InstructionContext

An InstructionContext offers convenient access to information like control flow successors and such.

Method Summary

Modifier and Type	Method	Description
boolean	execute(Frame inFrame, ArrayList<InstructionContext> executionPredecessors, InstConstraintVisitor icv, ExecutionVisitor ev)	This method symbolically executes the Instruction held in the InstructionContext.
ExceptionHandler[]	getExceptionHandlers()	Returns the exception handlers that protect this instruction.
Frame	getInFrame()
InstructionHandle	getInstruction()	Returns the InstructionHandle this InstructionContext is wrapped around.
Frame	getOutFrame(ArrayList<InstructionContext> executionPredecessors)	This method returns the outgoing execution frame situation; therefore it has to be calculated by execute(Frame, ArrayList) first.
InstructionContext[]	getSuccessors()	Returns the usual control flow successors.
int	getTag()	The getTag and setTag methods may be used for temporary flagging, such as graph colouring.
void	setTag(int tag)	The getTag and setTag methods may be used for temporary flagging, such as graph colouring.

Method Details

getTag

int getTag()

The getTag and setTag methods may be used for temporary flagging, such as graph colouring. Nothing in the InstructionContext object depends on the value of the tag. JustIce does not use it.

See Also:

• setTag(int tag)

setTag

void setTag(int tag)

The getTag and setTag methods may be used for temporary flagging, such as graph colouring. Nothing in the InstructionContext object depends on the value of the tag. JustIce does not use it.

See Also:

• getTag()

execute

boolean execute(Frame inFrame,
 ArrayList<InstructionContext> executionPredecessors,
 InstConstraintVisitor icv,
 ExecutionVisitor ev)

This method symbolically executes the Instruction held in the InstructionContext. It "merges in" the incoming execution frame situation (see The Java Virtual Machine Specification, 2nd edition, page 146). By so doing, the outgoing execution frame situation is calculated. This method is JustIce-specific and is usually of no sense for users of the ControlFlowGraph class. They should use getInstruction().accept(Visitor), possibly in conjunction with the ExecutionVisitor.

Returns:

true - if and only if the "outgoing" frame situation changed from the one before execute()ing.

See Also:

• ControlFlowGraph
• ExecutionVisitor
• getOutFrame(ArrayList)

getInFrame

Frame getInFrame()

getOutFrame

Frame getOutFrame(ArrayList<InstructionContext> executionPredecessors)

This method returns the outgoing execution frame situation; therefore it has to be calculated by execute(Frame, ArrayList) first.

See Also:

• execute(Frame, ArrayList, InstConstraintVisitor, ExecutionVisitor)

getInstruction

InstructionHandle getInstruction()

Returns the InstructionHandle this InstructionContext is wrapped around.

Returns:

The InstructionHandle this InstructionContext is wrapped around.

getSuccessors

InstructionContext[] getSuccessors()

Returns the usual control flow successors.

See Also:

• getExceptionHandlers()

getExceptionHandlers

ExceptionHandler[] getExceptionHandlers()

Returns the exception handlers that protect this instruction. They are special control flow successors.