Class for splitting up Varnodes that hold 2 logical variables. More...

#include <subflow.hh>

Inheritance diagram for SplitFlow:

Public Member Functions
	SplitFlow (Funcdata f, Varnode root, int4 lowSize)
	Constructor.

bool	doTrace (void)
	Trace split through data-flow, constructing transform. More...

Public Member Functions inherited from TransformManager
	TransformManager (Funcdata *f)
	Constructor.

virtual	~TransformManager (void)
	Destructor.

virtual bool	preserveAddress (Varnode *vn, int4 bitSize, int4 lsbOffset) const
	Should the address of the given Varnode be preserved when constructing a piece. More...

Funcdata *	getFunction (void) const
	Get function being transformed.

void	clearVarnodeMarks (void)
	Clear mark for all Varnodes in the map.

TransformVar *	newPreexistingVarnode (Varnode *vn)
	Make placeholder for preexisting Varnode. More...

TransformVar *	newUnique (int4 size)
	Make placeholder for new unique space Varnode. More...

TransformVar *	newConstant (int4 size, int4 lsbOffset, uintb val)
	Make placeholder for constant Varnode. More...

TransformVar *	newIop (Varnode *vn)
	Make placeholder for special iop constant. More...

TransformVar *	newPiece (Varnode *vn, int4 bitSize, int4 lsbOffset)
	Make placeholder for piece of a Varnode. More...

TransformVar *	newSplit (Varnode *vn, const LaneDescription &description)
	Create placeholder nodes splitting a Varnode into its lanes. More...

TransformVar *	newSplit (Varnode *vn, const LaneDescription &description, int4 numLanes, int4 startLane)
	Create placeholder nodes splitting a Varnode into a subset of lanes in the given description. More...

TransformOp *	newOpReplace (int4 numParams, OpCode opc, PcodeOp *replace)
	Create a new placeholder op intended to replace an existing op. More...

TransformOp *	newOp (int4 numParams, OpCode opc, TransformOp *follow)
	Create a new placeholder op that will not replace an existing op. More...

TransformOp *	newPreexistingOp (int4 numParams, OpCode opc, PcodeOp *originalOp)
	Create a new placeholder op for an existing PcodeOp. More...

TransformVar *	getPreexistingVarnode (Varnode *vn)
	Get (or create) placeholder for preexisting Varnode. More...

TransformVar *	getPiece (Varnode *vn, int4 bitSize, int4 lsbOffset)
	Get (or create) placeholder piece. More...

TransformVar *	getSplit (Varnode *vn, const LaneDescription &description)
	Find (or create) placeholder nodes splitting a Varnode into its lanes. More...

TransformVar *	getSplit (Varnode *vn, const LaneDescription &description, int4 numLanes, int4 startLane)
	Find (or create) placeholder nodes splitting a Varnode into a subset of lanes from a description. More...

void	opSetInput (TransformOp rop, TransformVar rvn, int4 slot)
	Mark given variable as input to given op. More...

void	opSetOutput (TransformOp rop, TransformVar rvn)
	Mark given variable as output of given op. More...

void	apply (void)
	Apply the full transform to the function.

Private Member Functions
TransformVar *	setReplacement (Varnode *vn)
	Find or build the placeholder objects for a Varnode that needs to be split. More...

bool	addOp (PcodeOp op, TransformVar rvn, int4 slot)
	Split given op into its lanes. More...

bool	traceForward (TransformVar *rvn)
	Try to trace the pair of logical values, forward, through ops that read them. More...

bool	traceBackward (TransformVar *rvn)
	Try to trace the pair of logical values, backward, through the defining op. More...

bool	processNextWork (void)
	Process the next logical value on the worklist. More...

Private Attributes
LaneDescription	laneDescription
	Description of how to split Varnodes.

vector< TransformVar * >	worklist
	Pending work list of Varnodes to push the split through.

Additional Inherited Members
Static Public Member Functions inherited from TransformManager
static bool	preexistingGuard (int4 slot, TransformVar *rvn)
	Should newPreexistingOp be called. More...

Detailed Description

Class for splitting up Varnodes that hold 2 logical variables.

Starting from a root Varnode provided to the constructor, this class looks for data-flow that consistently holds 2 logical values in a single Varnode. If doTrace() returns true, a consistent view has been created and invoking apply() will split all Varnodes and PcodeOps involved in the data-flow into their logical pieces.

Member Function Documentation

bool SplitFlow::addOp	(	PcodeOp *	op,
		TransformVar *	rvn,
		int4	slot
	)

private

Split given op into its lanes.

We assume op is a logical operation, or a COPY, or an INDIRECT. It must have an output. All inputs and output have their placeholders generated and added to the worklist if appropriate.

Parameters

op	is the given op
rvn	is a known parameter of the op
slot	is the incoming slot of the known parameter (-1 means parameter is output)

Returns: true if the op is successfully split

References PcodeOp::code(), CPUI_INDIRECT, TransformVar::getDef(), PcodeOp::getIn(), PcodeOp::getOut(), PcodeOp::numInput(), and SubvariableFlow::setReplacement().

bool SplitFlow::doTrace ( void )

Trace split through data-flow, constructing transform.

Push the logical split around, setting up the explicit transforms as we go. If at any point, the split cannot be naturally pushed, return false.

Returns: true if a full transform has been constructed that can perform the split

References TransformManager::clearVarnodeMarks(), processNextWork(), and worklist.

Referenced by RuleSplitFlow::applyOp().

bool SplitFlow::processNextWork ( void )

private

Process the next logical value on the worklist.

Returns: true if the logical split was successfully pushed through its local operators

References SubvariableFlow::traceBackward(), SubvariableFlow::traceForward(), and SubvariableFlow::worklist.

Referenced by doTrace().

TransformVar * SplitFlow::setReplacement ( Varnode * vn )

private

Find or build the placeholder objects for a Varnode that needs to be split.

Mark the Varnode so it doesn't get revisited. Decide if the Varnode needs to go into the worklist.

Parameters

vn	is the Varnode that needs to be split

Returns: the array of placeholders describing the split or null

References Varnode::isConstant(), Varnode::isFree(), Varnode::isInput(), Varnode::isMark(), Varnode::isTypeLock(), Varnode::setMark(), and SubvariableFlow::worklist.

Referenced by SplitFlow(), SubfloatFlow::traceBackward(), and SubfloatFlow::traceForward().

bool SplitFlow::traceBackward ( TransformVar * rvn )

private

Try to trace the pair of logical values, backward, through the defining op.

Create part of transform related to the defining op, and update the worklist as necessary.

Parameters

rvn	is the logical value to examine

Returns: false if the trace is not possible

References PcodeOp::code(), CPUI_COPY, CPUI_INDIRECT, CPUI_INT_AND, CPUI_INT_LEFT, CPUI_INT_OR, CPUI_INT_XOR, CPUI_INT_ZEXT, CPUI_MULTIEQUAL, CPUI_PIECE, Varnode::getDef(), PcodeOp::getIn(), Varnode::getOffset(), TransformVar::getOriginal(), PcodeOp::getOut(), Varnode::getSize(), Varnode::isConstant(), Varnode::isFree(), and Varnode::isWritten().

Referenced by SubfloatFlow::processNextWork().

bool SplitFlow::traceForward ( TransformVar * rvn )

private

Try to trace the pair of logical values, forward, through ops that read them.

Try to trace pieces of TransformVar pair forward, through reading ops, update worklist

Parameters

rvn	is the TransformVar pair to trace, as an array

Returns: true if logical pieces can be naturally traced, false otherwise

References Varnode::beginDescend(), PcodeOp::code(), CPUI_COPY, CPUI_INDIRECT, CPUI_INT_AND, CPUI_INT_LEFT, CPUI_INT_OR, CPUI_INT_RIGHT, CPUI_INT_SEXT, CPUI_INT_SRIGHT, CPUI_INT_XOR, CPUI_INT_ZEXT, CPUI_MULTIEQUAL, CPUI_SUBPIECE, Varnode::endDescend(), PcodeOp::getIn(), Varnode::getOffset(), TransformVar::getOriginal(), TransformOp::getOut(), PcodeOp::getOut(), Varnode::getSize(), PcodeOp::getSlot(), Varnode::isConstant(), and Varnode::isMark().

Referenced by SubfloatFlow::processNextWork().

The documentation for this class was generated from the following files:

subflow.hh
subflow.cc

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Member Function Documentation