ghidra::SplitDatatype::RootPointer Class Reference

A helper class describing the pointer being passed to a LOAD or STORE. More...

Public Member Functions
bool	find (PcodeOp *op, Datatype *valueType)
	Locate root pointer for underlying LOAD or STORE. More...
void	freePointerChain (Funcdata &data)
	Remove unused pointer calculations. More...

Private Member Functions
bool	backUpPointer (void)
	Follow flow of pointer back thru INT_ADD or PTRSUB. More...

Private Attributes
PcodeOp *	loadStore
	LOAD or STORE op.
TypePointer *	ptrType
	Base pointer data-type of LOAD or STORE.
Varnode *	firstPointer
	Direct pointer input for LOAD or STORE.
Varnode *	pointer
	The root pointer.
int4	baseOffset
	Offset of the LOAD or STORE relative to root pointer.

Friends
class	SplitDatatype

Detailed Description

A helper class describing the pointer being passed to a LOAD or STORE.

It makes distinction between the immediate pointer to the LOAD or STORE and a root pointer to the main structure or array, which the immediate pointer may be at an offset from.

Member Function Documentation

backUpPointer()

bool ghidra::SplitDatatype::RootPointer::backUpPointer ( void  )

private

Follow flow of pointer back thru INT_ADD or PTRSUB.

If pointer Varnode is written by an INT_ADD, PTRSUB, or PTRADD from a another pointer to a structure or array, update pointer Varnode, baseOffset, and ptrType to this.

Returns

true if pointer was successfully updated

References ghidra::SplitFlow::addOp(), ghidra::AddrSpace::addressToByteInt(), ghidra::PcodeOp::code(), ghidra::CPUI_INT_ADD, ghidra::CPUI_PTRADD, ghidra::CPUI_PTRSUB, ghidra::PcodeOp::getIn(), ghidra::Datatype::getMetatype(), ghidra::Varnode::getOffset(), ghidra::Varnode::getTypeReadFacing(), ghidra::Varnode::isConstant(), ghidra::TYPE_ARRAY, ghidra::TYPE_PTR, and ghidra::TYPE_STRUCT.

find()

bool ghidra::SplitDatatype::RootPointer::find	(	PcodeOp *	op,
		Datatype *	valueType
	)

Locate root pointer for underlying LOAD or STORE.

The LOAD or STORE pointer Varnode is examined. If it is a pointer to the given data-type, the root pointer is returned. If not, we try to recursively walk back through either PTRSUB or INT_ADD instructions, until a pointer Varnode matching the data-type is found. Any accumulated offset, relative to the original LOAD or STORE pointer is recorded in the baseOffset. If a matching pointer is not found, false is returned.

Parameters

op	is the LOAD or STORE
valueType	is the specific data-type to match

Returns

true if the root pointer is found

References ghidra::PcodeOp::getIn(), ghidra::Datatype::getMetatype(), ghidra::TYPE_PARTIALSTRUCT, and ghidra::TYPE_PTR.

Referenced by ghidra::SplitDatatype::splitLoad(), and ghidra::SplitDatatype::splitStore().

freePointerChain()

void ghidra::SplitDatatype::RootPointer::freePointerChain

(

Funcdata &

data

)

Remove unused pointer calculations.

If the pointer Varnode is no longer used, recursively check and remove the op producing it, which will be either an INT_ADD or PTRSUB, until the root pointer is reached or a Varnode still being used is encountered.

Parameters

data	is the containing function

References ghidra::PcodeOp::getIn(), and ghidra::Funcdata::opDestroy().

Referenced by ghidra::SplitDatatype::splitLoad(), and ghidra::SplitDatatype::splitStore().

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

• subflow.hh
• subflow.cc