ghidra::BooleanExpressionMatch Class Reference

A helper class for describing the similarity of the boolean condition between 2 CBRANCH operations. More...

#include <condexe.hh>

Public Member Functions
bool	verifyCondition (PcodeOp *op, PcodeOp *iop)
	Perform the correlation test on two CBRANCH operations.
int4	getMultiSlot (void) const
	Get the MULTIEQUAL slot in the critical path.
bool	getFlip (void) const
	Return true if the expressions are anti-correlated.

Private Types
enum	{ same = 1 , complementary = 2 , uncorrelated = 3 }

Static Private Member Functions
static bool	sameOpComplement (PcodeOp *bin1op, PcodeOp *bin2op)
	Test if two operations with same opcode produce complementary boolean values. More...
static bool	varnodeSame (Varnode *a, Varnode *b)
	Do the given Varnodes hold the same value, possibly as constants. More...
static int4	evaluate (Varnode *vn1, Varnode *vn2, int4 depth)
	Determine if two boolean Varnodes hold related values. More...

Private Attributes
bool	matchflip
	True if the compared CBRANCH keys on the opposite boolean value of the root.

Static Private Attributes
static const int4	maxDepth = 1
	Maximum depth to trace a boolean expression.

Detailed Description

A helper class for describing the similarity of the boolean condition between 2 CBRANCH operations.

This class determines if two CBRANCHs share the same condition. It also determines if the conditions are complements of each other, and/or they are shared along only one path.

Traverse (upto a specific depth) the two boolean expressions consisting of BOOL_AND, BOOL_OR, and BOOL_XOR operations. Leaf operators in the expression can be other operators with boolean output (INT_LESS, INT_SLESS, etc.).

Member Enumeration Documentation

anonymous enum

anonymous enum

private

Enumerator
same	Pair always hold the same value.
complementary	Pair always hold complementary values.
uncorrelated	Pair values are uncorrelated.

Member Function Documentation

evaluate()

int4 ghidra::BooleanExpressionMatch::evaluate ( Varnode *  vn1, Varnode *  vn2, int4  depth  )

staticprivate

Determine if two boolean Varnodes hold related values.

The values may be the same, or opposite of each other (complementary). Otherwise the values are uncorrelated. The trees constructing each Varnode are examined up to a maximum depth. If this is exceeded uncorrelated is returned.

Parameters

vn1	is the first boolean Varnode
vn2	is the second boolean Varnode
depth	is the maximum depth to traverse in the evaluation

Returns

the correlation class

References ghidra::PcodeOp::code(), complementary, ghidra::CPUI_BOOL_AND, ghidra::CPUI_BOOL_NEGATE, ghidra::CPUI_BOOL_OR, ghidra::CPUI_BOOL_XOR, ghidra::CPUI_MAX, evaluate(), ghidra::Varnode::getDef(), ghidra::PcodeOp::getIn(), ghidra::PcodeOp::isBoolOutput(), ghidra::Varnode::isWritten(), same, sameOpComplement(), uncorrelated, and varnodeSame().

Referenced by evaluate(), and verifyCondition().

sameOpComplement()

bool ghidra::BooleanExpressionMatch::sameOpComplement ( PcodeOp *  bin1op, PcodeOp *  bin2op  )

staticprivate

Test if two operations with same opcode produce complementary boolean values.

This only tests for cases where the opcode is INT_LESS or INT_SLESS and one of the inputs is constant.

Parameters

bin1op	is the first p-code op to compare
bin2op	is the second p-code op to compare

Returns

true if the two operations always produce complementary values

References ghidra::PcodeOp::code(), ghidra::CPUI_INT_LESS, ghidra::CPUI_INT_SLESS, ghidra::PcodeOp::getIn(), ghidra::Varnode::getOffset(), ghidra::Varnode::getSize(), ghidra::Varnode::isConstant(), and varnodeSame().

Referenced by evaluate().

varnodeSame()

bool ghidra::BooleanExpressionMatch::varnodeSame ( Varnode *  a, Varnode *  b  )

staticprivate

Do the given Varnodes hold the same value, possibly as constants.

Parameters

a	is the first Varnode to compare
b	is the second Varnode

Returns

true if the Varnodes (always) hold the same value

References ghidra::Varnode::getOffset(), and ghidra::Varnode::isConstant().

Referenced by evaluate(), and sameOpComplement().

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

• condexe.hh
• condexe.cc