Casting strategies that are specific to the C language. More...

#include <cast.hh>

Inheritance diagram for CastStrategyC:

Public Member Functions
virtual int4	localExtensionType (const Varnode *vn) const
	Decide on integer promotion by examining just local properties of the given Varnode. More...

virtual int4	intPromotionType (const Varnode *vn) const
	Calculate the integer promotion code of a given Varnode. More...

virtual bool	checkIntPromotionForCompare (const PcodeOp *op, int4 slot) const
	Check if integer promotion forces a cast for the given comparison op and slot. More...

virtual bool	checkIntPromotionForExtension (const PcodeOp *op) const
	Check if integer promotion forces a cast for the input to the given extension. More...

virtual Datatype *	castStandard (Datatype reqtype, Datatype curtype, bool care_uint_int, bool care_ptr_uint) const
	Does there need to be a visible cast between the given data-types. More...

virtual Datatype *	arithmeticOutputStandard (const PcodeOp *op)
	What is the output data-type produced by the given integer arithmetic operation. More...

virtual bool	isSubpieceCast (Datatype outtype, Datatype intype, uint4 offset) const
	Is truncating an input data-type, producing an output data-type, considered a cast. More...

virtual bool	isSubpieceCastEndian (Datatype outtype, Datatype intype, uint4 offset, bool isbigend) const
	Is the given data-type truncation considered a cast, given endianess concerns. More...

virtual bool	isSextCast (Datatype outtype, Datatype intype) const
	Is sign-extending an input data-type, producing an output data-type, considered a cast. More...

virtual bool	isZextCast (Datatype outtype, Datatype intype) const
	Is zero-extending an input data-type, producing an output data-type, considered a cast. More...

Public Member Functions inherited from CastStrategy
	CastStrategy (void)
	Constructor.

void	setTypeFactory (TypeFactory *t)
	Establish the data-type factory. More...

virtual	~CastStrategy (void)
	Destructor.

Additional Inherited Members
Public Types inherited from CastStrategy
enum	IntPromotionCode { NO_PROMOTION = -1, UNKNOWN_PROMOTION = 0, UNSIGNED_EXTENSION = 1, SIGNED_EXTENSION = 2, EITHER_EXTENSION = 3 }
	Types of integer promotion. More...

Protected Attributes inherited from CastStrategy
TypeFactory *	tlst
	Type factory associated with the Architecture.

int4	promoteSize
	Size of int data-type, (size that integers get promoted to)

Detailed Description

Casting strategies that are specific to the C language.

Member Function Documentation

◆ arithmeticOutputStandard()

Datatype * CastStrategyC::arithmeticOutputStandard ( const PcodeOp * op )

virtual

What is the output data-type produced by the given integer arithmetic operation.

Parameters

op	is the given operation

Returns: the output data-type

Implements CastStrategy.

References TypeFactory::getBase(), Varnode::getHigh(), PcodeOp::getIn(), Datatype::getMetatype(), Datatype::getSize(), HighVariable::getType(), PcodeOp::numInput(), CastStrategy::tlst, TYPE_BOOL, TYPE_INT, and Datatype::typeOrder().

◆ castStandard()

Datatype * CastStrategyC::castStandard	(	Datatype *	reqtype,
		Datatype *	curtype,
		bool	care_uint_int,
		bool	care_ptr_uint
	)		const

virtual

Does there need to be a visible cast between the given data-types.

The cast is from a current data-type to an expected data-type. NULL is returned if no cast is required, otherwise the data-type to cast to (usually the expected data-type) is returned.

Parameters

reqtype	is the expected data-type
curtype	is the current data-type
care_uint_int	is true if we care about a change in signedness
care_ptr_uint	is true if we care about conversions between pointers and unsigned values

Returns: NULL to indicate no cast, or the data-type to cast to

Implements CastStrategy.

Reimplemented in CastStrategyJava.

References Datatype::getMetatype(), Datatype::getSize(), TYPE_BOOL, TYPE_CODE, TYPE_INT, TYPE_PTR, TYPE_UINT, TYPE_UNKNOWN, and TYPE_VOID.

◆ checkIntPromotionForCompare()

bool CastStrategyC::checkIntPromotionForCompare	(	const PcodeOp *	op,
		int4	slot
	)		const

virtual

Check if integer promotion forces a cast for the given comparison op and slot.

Compute to what level the given slot has seen integer promotion and if a cast is required before the comparison operator makes sense.

Parameters

op	is the given comparison operator
slot	is the input slot being tested

Returns: true if a cast is required before comparing

Implements CastStrategy.

References PcodeOp::getIn(), intPromotionType(), CastStrategy::NO_PROMOTION, and CastStrategy::UNKNOWN_PROMOTION.

◆ checkIntPromotionForExtension()

bool CastStrategyC::checkIntPromotionForExtension ( const PcodeOp * op ) const

virtual

Check if integer promotion forces a cast for the input to the given extension.

Compute to what level the given slot has seen integer promotion and if a cast is required before the extension operator makes sense.

Parameters

op	is the given extension operator INT_ZEXT or INT_SEXT

Returns: true if a cast is required before extending

Implements CastStrategy.

References PcodeOp::code(), CPUI_INT_SEXT, CPUI_INT_ZEXT, PcodeOp::getIn(), intPromotionType(), CastStrategy::NO_PROMOTION, CastStrategy::SIGNED_EXTENSION, CastStrategy::UNKNOWN_PROMOTION, and CastStrategy::UNSIGNED_EXTENSION.

◆ intPromotionType()

int4 CastStrategyC::intPromotionType ( const Varnode * vn ) const

virtual

Calculate the integer promotion code of a given Varnode.

Recursively examine the expression defining the Varnode as necessary

Parameters

vn	is the given Varnode

Returns: the IntPromotionCode

Implements CastStrategy.

References PcodeOp::code(), CPUI_INT_2COMP, CPUI_INT_ADD, CPUI_INT_AND, CPUI_INT_DIV, CPUI_INT_LEFT, CPUI_INT_MULT, CPUI_INT_NEGATE, CPUI_INT_OR, CPUI_INT_REM, CPUI_INT_RIGHT, CPUI_INT_SDIV, CPUI_INT_SREM, CPUI_INT_SRIGHT, CPUI_INT_SUB, CPUI_INT_XOR, Varnode::getDef(), PcodeOp::getIn(), Varnode::getSize(), Varnode::isConstant(), Varnode::isExplicit(), Varnode::isWritten(), localExtensionType(), CastStrategy::NO_PROMOTION, CastStrategy::promoteSize, CastStrategy::SIGNED_EXTENSION, CastStrategy::UNKNOWN_PROMOTION, and CastStrategy::UNSIGNED_EXTENSION.

Referenced by checkIntPromotionForCompare(), and checkIntPromotionForExtension().

◆ isSextCast()

bool CastStrategyC::isSextCast	(	Datatype *	outtype,
		Datatype *	intype
	)		const

virtual

Is sign-extending an input data-type, producing an output data-type, considered a cast.

Data-types must be provided from the input and output of an INT_SEXT operation.

Parameters

outtype	is the output data-type
intype	is the input data-type

Returns: true if the INT_SEXT should be represented as a cast

Implements CastStrategy.

References Datatype::getMetatype(), TYPE_BOOL, TYPE_INT, and TYPE_UINT.

◆ isSubpieceCast()

bool CastStrategyC::isSubpieceCast	(	Datatype *	outtype,
		Datatype *	intype,
		uint4	offset
	)		const

virtual

Is truncating an input data-type, producing an output data-type, considered a cast.

Data-types must be provided from the input and output of a SUBPIECE operation.

Parameters

outtype	is the output data-type
intype	is the input data-type
offset	is number of bytes truncated by the SUBPIECE

Returns: true if the SUBPIECE should be represented as a cast

Implements CastStrategy.

References Datatype::getMetatype(), TYPE_FLOAT, TYPE_INT, TYPE_PTR, TYPE_UINT, and TYPE_UNKNOWN.

Referenced by isSubpieceCastEndian().

◆ isSubpieceCastEndian()

bool CastStrategyC::isSubpieceCastEndian	(	Datatype *	outtype,
		Datatype *	intype,
		uint4	offset,
		bool	isbigend
	)		const

virtual

Is the given data-type truncation considered a cast, given endianess concerns.

This is equivalent to isSubpieceCast() but where the truncation is accomplished by pulling bytes directly out of memory. We assume the input data-type is layed down in memory, and we pull the output value starting at a given byte offset.

Parameters

outtype	is the output data-type
intype	is the input data-type
offset	is the given byte offset (into the input memory)
isbigend	is true if the address space holding the memory is big endian.