LaneDescription Class Reference

Description of logical lanes within a big Varnode. More...

#include <transform.hh>

Public Member Functions
	LaneDescription (const LaneDescription &op2)
	Copy constructor. More...
	LaneDescription (int4 origSize, int4 sz)
	Construct uniform lanes. More...
	LaneDescription (int4 origSize, int4 lo, int4 hi)
	Construct two lanes of arbitrary size. More...
bool	subset (int4 lsbOffset, int4 size)
	Trim this to a subset of the original lanes. More...
int4	getNumLanes (void) const
	Get the total number of lanes.
int4	getWholeSize (void) const
	Get the size of the region being split.
int4	getSize (int4 i) const
	Get the size of the i-th lane.
int4	getPosition (int4 i) const
	Get the significance offset of the i-th lane.
int4	getBoundary (int4 bytePos) const
	Get index of lane that starts at the given byte position. More...
bool	restriction (int4 numLanes, int4 skipLanes, int4 bytePos, int4 size, int4 &resNumLanes, int4 &resSkipLanes) const
	Decide if a given truncation is natural for this description. More...
bool	extension (int4 numLanes, int4 skipLanes, int4 bytePos, int4 size, int4 &resNumLanes, int4 &resSkipLanes) const
	Decide if a given subset of lanes can be extended naturally for this description. More...

Private Attributes
int4	wholeSize
	Size of the region being split in bytes.
vector< int4 >	laneSize
	Size of lanes in bytes.
vector< int4 >	lanePosition
	Significance positions of lanes in bytes.

Detailed Description

Description of logical lanes within a big Varnode.

A lane is a byte offset and size within a Varnode. Lanes within a Varnode are disjoint. In general, we expect a Varnode to be tiled with lanes all of the same size, but the API allows for possibly non-uniform lanes.

Constructor & Destructor Documentation

LaneDescription::LaneDescription

(

const LaneDescription &

op2

)

Copy constructor.

Parameters

op2	is the lane description to copy from

References lanePosition, laneSize, and wholeSize.

LaneDescription::LaneDescription	(	int4	origSize,
		int4	sz
	)

Construct uniform lanes.

Create lanes that are all the same size

Parameters

origSize	is the size of the whole in bytes
sz	is the size of a lane in bytes

References lanePosition, laneSize, and wholeSize.

LaneDescription::LaneDescription	(	int4	origSize,
		int4	lo,
		int4	hi
	)

Construct two lanes of arbitrary size.

Parameters

origSize	is the size of the whole in bytes
lo	is the size of the least significant lane in bytes
hi	is the size of the most significant lane in bytes

References lanePosition, laneSize, and wholeSize.

Member Function Documentation

bool LaneDescription::extension	(	int4	numLanes,
		int4	skipLanes,
		int4	bytePos,
		int4	size,
		int4 &	resNumLanes,
		int4 &	resSkipLanes
	)		const

Decide if a given subset of lanes can be extended naturally for this description.

A subset of lanes are specified and their position within an extension (given by a byte position). The size in bytes of the extension is also given. If the extension is contained within this description, and the boundaries of the extension don't split any lanes, then return true and pass back the number of lanes and starting lane of the extension.

Parameters

numLanes	is the number of lanes in the original subset
skipLanes	is the starting (least significant) lane index of the original subset
bytePos	is the number of bytes to truncate from the front (least significant portion) of the extension
size	is the number of bytes in the extension
resNumLanes	will hold the number of lanes in the extension
resSkipLanes	will hold the starting lane in the extension

Returns

true if the extension is natural

References getBoundary(), and lanePosition.

int4 LaneDescription::getBoundary

(

int4

bytePos

)

const

Get index of lane that starts at the given byte position.

Position 0 will map to index 0 and a position equal to whole size will map to the number of lanes. Positions that are out of bounds or that do not fall on a lane boundary will return -1.

Parameters

bytePos

is the given byte position to test

Returns

the index of the lane that start at the given position

References lanePosition, and wholeSize.

Referenced by extension(), restriction(), and subset().

bool LaneDescription::restriction	(	int4	numLanes,
		int4	skipLanes,
		int4	bytePos,
		int4	size,
		int4 &	resNumLanes,
		int4 &	resSkipLanes
	)		const

Decide if a given truncation is natural for this description.

A subset of lanes are specified and a truncation (given by a byte position and byte size). If the truncation, relative to the subset, contains at least 1 lane and does not split any lanes, then return true and pass back the number of lanes and starting lane of the truncation.

Parameters

numLanes	is the number of lanes in the original subset
skipLanes	is the starting (least significant) lane index of the original subset
bytePos	is the number of bytes to truncate from the front (least significant portion) of the subset
size	is the number of bytes to include in the truncation
resNumLanes	will hold the number of lanes in the truncation
resSkipLanes	will hold the starting lane in the truncation

Returns

true if the truncation is natural

References getBoundary(), and lanePosition.

bool LaneDescription::subset	(	int4	lsbOffset,
		int4	size
	)

Trim this to a subset of the original lanes.

Given a subrange, specified as an offset into the whole and size, throw out any lanes in this that aren't in the subrange, so that the size of whole is the size of the subrange. If the subrange intersects partially with any of the lanes, return false.

Parameters

lsbOffset	is the number of bytes to remove from the front of the description
size	is the number of bytes in the subrange

Returns

true if this was successfully transformed to the subrange

References getBoundary(), lanePosition, laneSize, and wholeSize.

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

• transform.hh
• transform.cc