ghidra::BitRange Class Reference

An endian aware range of bits contained in a contiguous set of bytes. More...

#include <address.hh>

Public Member Functions
	BitRange (void)
	Construct undefined range.
	BitRange (int4 bOff, int4 bSize, bool bigEndian)
	Construct byte range.
	BitRange (const BitRange &op2, int4 off, int4 sz)
	Constructor, copy range into new container.
	BitRange (int4 bOff, int4 bSize, int4 least, int4 num, bool bigEndian)
	Constructor.
bool	empty (void) const
	Return true if this is an empty bit range (zero bits)
int4	compare (const BitRange &op2) const
	Compare this with another as containers.
int4	translateLSB (const BitRange &op2) const
	Translate the leastSigBit of the given range into this reference frame.
int4	overlapTest (const BitRange &op2) const
	Characterize the type of overlap between this and another range.
void	intersection (const BitRange &op2)
	Replace this with the intersection of this with another BitRange.
void	intersectMask (uintb mask)
	Restrict this with a mask that lines up with the container.
void	shift (int4 leftShiftAmount)
	Replace this with the shifted range.
void	truncateMostSigBytes (int4 num)
	Truncate the most significant bytes in the byte container.
void	truncateLeastSigBytes (int4 num)
	Truncate the least significant bytes in the byte container.
void	extendBytes (int4 num)
	Add most significant bytes to the container.
uintb	getMask (void) const
	Get mask representing this range.
bool	isByteRange (void) const
	Return true if this bit range is also a byte range.
bool	isMostSignificant (void) const
	Return true if the bit range occupies the most significant bits of the container.
void	minimizeContainer (void)
	Shrink the container to fit the bit range.
void	expandToMost (void)
	Expand the bitrange until it includes the most significant bits of the container.

Public Attributes
int4	byteOffset
	Byte offset of the region containing the range.
int4	byteSize
	Size of the region in bytes.
int4	leastSigBit
	Least significant bit of the bit-range within its region.
int4	numBits
	Number of bits in the range.
bool	isBigEndian
	Is the underlying encoding big endian.

Detailed Description

An endian aware range of bits contained in a contiguous set of bytes.

Member Function Documentation

compare()

int4 ghidra::BitRange::compare

(

const BitRange &

op2

)

const

Compare this with another as containers.

Both the byte container and the bit range are compared and must be equal to return 0.

Parameters

op2	is the other bit range to compare with

Returns

-1, 0, or 1 to establish ordering the two ranges

References byteOffset, byteSize, leastSigBit, and numBits.

Referenced by ghidra::TypeBitField::compare(), and ghidra::TypeBitField::compareDependency().

extendBytes()

void ghidra::BitRange::extendBytes

(

int4

num

)

Add most significant bytes to the container.

Only the container is affected, the bit range itself does not change.

Parameters

num	is the number of bytes to add

References byteOffset, byteSize, and isBigEndian.

Referenced by ghidra::BitFieldTransform::findOverwrite(), and ghidra::BitFieldInsertTransform::handleSubpieceBack().

getMask()

uintb ghidra::BitRange::getMask

(

void

)

const

Get mask representing this range.

The bit-mask is aligned with the byte container.

Returns

the bit-mask describing this range

References leastSigBit, and numBits.

Referenced by ghidra::BitFieldInsertTransform::addConstantWrite(), ghidra::BitFieldInsertTransform::handleAddBack(), ghidra::BitFieldInsertTransform::handleAndBack(), ghidra::BitFieldPullTransform::handleAndForward(), ghidra::BitFieldPullTransform::handleEqualForward(), ghidra::BitFieldInsertTransform::handleOrBack(), intersectMask(), and ghidra::BitFieldPullTransform::testConsumed().

intersection()

void ghidra::BitRange::intersection

(

const BitRange &

op2

)

Replace this with the intersection of this with another BitRange.

The byte container for this does not change only leastSigBit and numBits. If the intersection is empty, numBits is set to 0.

Parameters

op2	is the bit range to intersect with this.

References leastSigBit, numBits, and translateLSB().

intersectMask()

void ghidra::BitRange::intersectMask

(

uintb

mask

)

Restrict this with a mask that lines up with the container.

The range of bits is intersected with the 1-bits of the mask. The resulting range is the minimal cover of the bits in the intersection.

Parameters

mask	is the mask to intersect with

References getMask(), leastSigBit, and numBits.

Referenced by ghidra::BitFieldTransform::findOverwrite(), ghidra::BitFieldInsertTransform::handleAndBack(), and ghidra::BitFieldInsertTransform::processBackward().

isByteRange()

bool ghidra::BitRange::isByteRange

(

void

)

const

Return true if this bit range is also a byte range.

Returns

true if the beginning and end of the range fall on byte boundaries

References leastSigBit, and numBits.

Referenced by ghidra::TypeStruct::decodeBitField().

isMostSignificant()

bool ghidra::BitRange::isMostSignificant

(

void

)

const

Return true if the bit range occupies the most significant bits of the container.

Returns

true if the most significant bit of the field and the container are the same

References byteSize, leastSigBit, and numBits.

Referenced by ghidra::BitFieldNodeState::BitFieldNodeState(), ghidra::BitFieldPullTransform::handleAndForward(), ghidra::BitFieldPullTransform::handleLeftForward(), ghidra::BitFieldPullTransform::handleLessForward(), and ghidra::BitFieldPullTransform::handleMultForward().

overlapTest()

int4 ghidra::BitRange::overlapTest

(

const BitRange &

op2

)

const

Characterize the type of overlap between this and another range.

Return:

• -1 if this should come before (no intersection)
• 0 if this and op2 are the same bitrange
• 1 if this should come after (no intersection)
• 2 if this is contained in op2
• 3 if op2 is contained in this
• 4 if partial overlap

Parameters

op2	is the other range to compare

Returns

the intersection code

this contained in op2

op2 contained in this

References isBigEndian, leastSigBit, numBits, and translateLSB().

Referenced by ghidra::TypeStruct::collectBitFields(), ghidra::BitFieldTransform::establishFields(), ghidra::TypeStruct::findMatchingBitField(), and ghidra::TypeStruct::hasBitFieldsInRange().

shift()

void ghidra::BitRange::shift

(

int4

leftShiftAmount

)

Replace this with the shifted range.

The bit range is shifted to the left by the given amount.

Parameters

leftShiftAmount

is the amount to shift the range by

References byteSize, leastSigBit, and numBits.

Referenced by ghidra::BitFieldTransform::findOverwrite(), ghidra::BitFieldInsertTransform::handleLeftBack(), ghidra::BitFieldPullTransform::handleLeftForward(), ghidra::BitFieldInsertTransform::handleMultBack(), ghidra::BitFieldPullTransform::handleMultForward(), ghidra::BitFieldInsertTransform::handleRightBack(), ghidra::BitFieldPullTransform::handleRightForward(), and ghidra::BitFieldInsertTransform::handleSubpieceBack().

translateLSB()

int4 ghidra::BitRange::translateLSB

(

const BitRange &

op2

)

const

Translate the leastSigBit of the given range into this reference frame.

The returned result is directly comparable with leastSigBit for determining order/overlap.

Parameters

op2	is the other BitRange to translate into this frame

Returns

the translated value of op2.leastSigBit

References byteOffset, byteSize, isBigEndian, and leastSigBit.

Referenced by BitRange(), ghidra::BitFieldTransform::establishFields(), intersection(), and overlapTest().

truncateLeastSigBytes()

void ghidra::BitRange::truncateLeastSigBytes

(

int4

num

)

Truncate the least significant bytes in the byte container.

Parameters

num	is the number of bytes to truncate

References byteOffset, byteSize, isBigEndian, leastSigBit, and numBits.

Referenced by ghidra::BitFieldPullTransform::handleSubpieceForward().

truncateMostSigBytes()

void ghidra::BitRange::truncateMostSigBytes

(

int4

num

)

Truncate the most significant bytes in the byte container.

The number of bits may be affected.

Parameters

num	is the number of bytes to truncate

References byteOffset, byteSize, isBigEndian, leastSigBit, and numBits.

Referenced by ghidra::BitFieldPullTransform::handleSubpieceForward(), and ghidra::BitFieldInsertTransform::handleZextBack().

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

• address.hh
• address.cc