expression.hh File Reference

Classes to collect, analyze, and match expressions within p-code data-flow. More...

#include "op.hh"

Classes
struct	ghidra::PcodeOpNode
	An edge in a data-flow path or graph. More...
struct	ghidra::TraverseNode
	Node for a forward traversal of a Varnode expression. More...
class	ghidra::BooleanMatch
	Static methods for determining if two boolean expressions are the same or complementary. More...
class	ghidra::BooleanExpressionMatch
	A helper class for describing the similarity of the boolean condition between 2 CBRANCH operations. More...
class	ghidra::AdditiveEdge
	Class representing a term in an additive expression. More...
class	ghidra::TermOrder
	A class for ordering Varnode terms in an additive expression. More...
class	ghidra::AddExpression
	Class for lightweight matching of two additive expressions. More...
class	ghidra::AddExpression::Term
	A term in the expression. More...
class	ghidra::BitFieldExpression
	A container for an expression manipulating a bitfield. More...
class	ghidra::InsertExpression
	A write to a bitfield stored in an explicit Varnode. More...
class	ghidra::InsertStoreExpression
	A write to a bitfield through a STORE op. More...
class	ghidra::PullExpression
	A read of a bitfield via a ZPULL or SPULL operator. More...

Functions
int4	ghidra::functionalEqualityLevel (Varnode *vn1, Varnode *vn2, Varnode **res1, Varnode **res2)
	Try to determine if vn1 and vn2 contain the same value.
bool	ghidra::functionalEquality (Varnode *vn1, Varnode *vn2)
	Determine if two Varnodes hold the same value.
bool	ghidra::functionalDifference (Varnode *vn1, Varnode *vn2, int4 depth)
	Return true if vn1 and vn2 are verifiably different values.
Varnode *	ghidra::rootPointer (Varnode *vn, uintb &offset)
	Back-track as far as possible from a pointer Varnode thru PTRSUB, INT_ADD, and COPY collecting offsets.
bool	ghidra::pointerEquality (Varnode *vn1, Varnode *vn2)
	Determine if two pointer Varnodes always hold the same value.

Detailed Description

Classes to collect, analyze, and match expressions within p-code data-flow.

Function Documentation

functionalDifference()

bool ghidra::functionalDifference	(	Varnode *	vn1,
		Varnode *	vn2,
		int4	depth
	)

Return true if vn1 and vn2 are verifiably different values.

This is actually a rather speculative test

Parameters

vn1	is the first Varnode to compare
vn2	is the second Varnode
depth	is the maximum level to recurse while testing

Returns

true if they are different

functionalEquality()

bool ghidra::functionalEquality	(	Varnode *	vn1,
		Varnode *	vn2
	)

Determine if two Varnodes hold the same value.

Only return true if it can be immediately determined they are equivalent

Parameters

vn1	is the first Varnode
vn2	is the second Varnode

Returns

true if they are provably equal

functionalEqualityLevel()

int4 ghidra::functionalEqualityLevel	(	Varnode *	vn1,
		Varnode *	vn2,
		Varnode **	res1,
		Varnode **	res2
	)

Try to determine if vn1 and vn2 contain the same value.

Return:

• -1, if they do not, or if it can't be immediately verified
• 0, if they do hold the same value
• >0, if the result is contingent on additional varnode pairs having the same value In the last case, the varnode pairs are returned as (res1[i],res2[i]), where the return value is the number of pairs.

  Parameters

  vn1	is the first Varnode to compare
  vn2	is the second Varnode
  res1	is a reference to the first returned Varnode
  res2	is a reference to the second returned Varnode

  Returns

  the result of the comparison

pointerEquality()

bool ghidra::pointerEquality	(	Varnode *	vn1,
		Varnode *	vn2
	)

Determine if two pointer Varnodes always hold the same value.

Parameters

vn1	is the first pointer to compare
vn2	is the second pointer to compare

rootPointer()

Varnode * ghidra::rootPointer	(	Varnode *	vn,
		uintb &	offset
	)

Back-track as far as possible from a pointer Varnode thru PTRSUB, INT_ADD, and COPY collecting offsets.

The pointer that is reached by back-tracking is returned, and any accumulated offset is passed back.

Parameters

vn	is the pointer Varnode
offset	passes back the accumulated offset

Returns

the reached Varnode pointer