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 bool	isExtensionCastImplied (const PcodeOp op, const PcodeOp readOp) const
	Is the given ZEXT/SEXT cast implied by the expression its in? 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

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().

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(), Datatype::hasSameVariableBase(), Datatype::isVariableLength(), TYPE_BOOL, TYPE_CODE, TYPE_INT, TYPE_PTR, TYPE_UINT, TYPE_UNKNOWN, and TYPE_VOID.

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(), CastStrategy::intPromotionType(), CastStrategy::NO_PROMOTION, and CastStrategy::UNKNOWN_PROMOTION.

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(), CastStrategy::intPromotionType(), CastStrategy::NO_PROMOTION, CastStrategy::SIGNED_EXTENSION, CastStrategy::UNKNOWN_PROMOTION, and CastStrategy::UNSIGNED_EXTENSION.

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(), CastStrategy::localExtensionType(), CastStrategy::NO_PROMOTION, CastStrategy::promoteSize, CastStrategy::SIGNED_EXTENSION, CastStrategy::UNKNOWN_PROMOTION, and CastStrategy::UNSIGNED_EXTENSION.

bool CastStrategyC::isExtensionCastImplied	(	const PcodeOp *	op,
		const PcodeOp *	readOp
	)		const

virtual

Is the given ZEXT/SEXT cast implied by the expression its in?

We've already determined that the given ZEXT or SEXT op can be viewed as a natural cast operation. Determine if the cast is implied by the expression its and doesn't need to be printed.

Parameters

op	is the given ZEXT or SEXT PcodeOp
readOp	is the PcodeOp consuming the output of the extensions (or null)

Returns: true if the op as a cast does not need to be printed

Implements CastStrategy.

References PcodeOp::code(), CPUI_INT_ADD, CPUI_INT_AND, CPUI_INT_DIV, CPUI_INT_EQUAL, CPUI_INT_LESS, CPUI_INT_LESSEQUAL, CPUI_INT_MULT, CPUI_INT_NOTEQUAL, CPUI_INT_OR, CPUI_INT_SLESS, CPUI_INT_SLESSEQUAL, CPUI_INT_SUB, CPUI_INT_XOR, CPUI_PTRADD, Varnode::getHigh(), PcodeOp::getIn(), Datatype::getMetatype(), PcodeOp::getOut(), Varnode::getSize(), PcodeOp::getSlot(), HighVariable::getType(), Varnode::isConstant(), Varnode::isExplicit(), and CastStrategy::promoteSize.

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.

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

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.

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

Implements CastStrategy.

References Datatype::getSize(), and CastStrategy::isSubpieceCast().

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

virtual

Is zero-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_ZEXT operation.

Parameters

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

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

Implements CastStrategy.

Reimplemented in CastStrategyJava.

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

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

virtual

Decide on integer promotion by examining just local properties of the given Varnode.

Parameters

vn	is the given Varnode

Returns: an IntPromotionCode (excluding NO_PROMOTION)

Implements CastStrategy.

References PcodeOp::code(), CPUI_CAST, CPUI_INT_AND, CPUI_LOAD, CastStrategy::EITHER_EXTENSION, Varnode::getDef(), Varnode::getHigh(), PcodeOp::getIn(), Datatype::getMetatype(), Varnode::getOffset(), Varnode::getSize(), HighVariable::getType(), PcodeOp::isBoolOutput(), PcodeOp::isCall(), Varnode::isConstant(), Varnode::isExplicit(), Varnode::isWritten(), signbit_negative(), CastStrategy::SIGNED_EXTENSION, TYPE_BOOL, TYPE_INT, TYPE_UINT, TYPE_UNKNOWN, CastStrategy::UNKNOWN_PROMOTION, and CastStrategy::UNSIGNED_EXTENSION.

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

cast.hh
cast.cc

Public Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation