Simplify various conditional move situations. More...

Inheritance diagram for ghidra::RuleConditionalMove:

Collaboration diagram for ghidra::RuleConditionalMove:

Public Member Functions
	RuleConditionalMove (const string &g)
	Constructor.

virtual Rule *	clone (const ActionGroupList &grouplist) const
	Clone the Rule.

virtual void	getOpList (vector< uint4 > &oplist) const
	List of op codes this rule operates on.

virtual int4	applyOp (PcodeOp *op, Funcdata &data)
	Attempt to apply this Rule.

Public Member Functions inherited from ghidra::Rule
	Rule (const string &g, uint4 fl, const string &nm)
	Construct given group, properties name.

virtual	~Rule (void)
	Destructor.

const string &	getName (void) const
	Return the name of this Rule.

const string &	getGroup (void) const
	Return the group this Rule belongs to.

uint4	getNumTests (void)
	Get number of attempted applications.

uint4	getNumApply (void)
	Get number of successful applications.

void	setBreak (uint4 tp)
	Set a breakpoint on this Rule.

void	clearBreak (uint4 tp)
	Clear a breakpoint on this Rule.

void	clearBreakPoints (void)
	Clear all breakpoints on this Rule.

void	turnOnWarnings (void)
	Enable warnings for this Rule.

void	turnOffWarnings (void)
	Disable warnings for this Rule.

bool	isDisabled (void) const
	Return true if this Rule is disabled.

void	setDisable (void)
	Disable this Rule (within its pool)

void	clearDisable (void)
	Enable this Rule (within its pool)

bool	checkActionBreak (void)
	Check if an action breakpoint is turned on.

uint4	getBreakPoint (void) const
	Return breakpoint toggles.

virtual void	reset (Funcdata &data)
	Reset this Rule.

virtual void	resetStats (void)
	Reset Rule statistics.

virtual void	printStatistics (ostream &s) const
	Print statistics for this Rule.

Static Private Member Functions
static Varnode *	checkBoolean (Varnode *vn)
	Check for boolean expression.

static bool	gatherExpression (Varnode vn, vector< PcodeOp > &ops, FlowBlock root, FlowBlock branch)
	Determine if the given expression can be propagated out of the condition.

static Varnode *	constructBool (Varnode vn, PcodeOp insertop, vector< PcodeOp * > &ops, Funcdata &data)
	Construct the expression after the merge.

static bool	compareOp (PcodeOp op0, PcodeOp op1)

Additional Inherited Members
Public Types inherited from ghidra::Rule
enum	typeflags { type_disable = 1 , rule_debug = 2 , warnings_on = 4 , warnings_given = 8 }
	Properties associated with a Rule. More...

Detailed Description

Simplify various conditional move situations.

The simplest situation is when the code looks like

if (boolcond)
  res0 = 1;
else
  res1 = 0;
res = ? res0 : res1

which gets simplified to res = zext(boolcond) The other major variation looks like

if (boolcond)
   res0 = boolcond;
else
   res1 = differentcond;
res = ? res0 : res1

which gets simplified to res = boolcond || differentcond

Member Function Documentation

◆ applyOp()

int4 ghidra::RuleConditionalMove::applyOp	(	PcodeOp *	op,
		Funcdata &	data
	)

virtual

Attempt to apply this Rule.

This method contains the main logic for applying the Rule. It must use a given PcodeOp as the point at which the Rule applies. If it does apply, changes are made directly to the function and 1 (non-zero) is returned, otherwise 0 is returned.

Parameters

op	is the given PcodeOp where the Rule may apply
data	is the function to which to apply

Reimplemented from ghidra::Rule.

References checkBoolean(), ghidra::PcodeOp::code(), constructBool(), ghidra::CPUI_BOOL_AND, ghidra::CPUI_BOOL_NEGATE, ghidra::CPUI_BOOL_OR, ghidra::CPUI_CBRANCH, ghidra::CPUI_COPY, ghidra::CPUI_INT_ZEXT, gatherExpression(), ghidra::Varnode::getDef(), ghidra::FlowBlock::getIn(), ghidra::PcodeOp::getIn(), ghidra::Varnode::getOffset(), ghidra::PcodeOp::getOut(), ghidra::PcodeOp::getParent(), ghidra::Varnode::getSize(), ghidra::FlowBlock::getTrueOut(), ghidra::PcodeOp::isBooleanFlip(), ghidra::Varnode::isConstant(), ghidra::Varnode::isWritten(), ghidra::FlowBlock::lastOp(), ghidra::Funcdata::newConstant(), ghidra::PcodeOp::numInput(), ghidra::Funcdata::opBoolNegate(), ghidra::Funcdata::opInsertBegin(), ghidra::Funcdata::opRemoveInput(), ghidra::Funcdata::opSetInput(), ghidra::Funcdata::opSetOpcode(), ghidra::Funcdata::opUninsert(), ghidra::FlowBlock::sizeIn(), and ghidra::FlowBlock::sizeOut().

◆ checkBoolean()

Varnode * ghidra::RuleConditionalMove::checkBoolean ( Varnode * vn )

staticprivate

Check for boolean expression.

Check if the given Varnode is a boolean value and return the root of the expression. The Varnode is assumed to be an input to a MULTIEQUAL.

Parameters

vn	is the given Varnode

Returns: null if the Varnode is not a boolean value, otherwise return the root Varnode of the expression

References ghidra::PcodeOp::code(), ghidra::CPUI_COPY, ghidra::Varnode::getDef(), ghidra::PcodeOp::getIn(), ghidra::Varnode::getOffset(), ghidra::PcodeOp::isBoolOutput(), ghidra::Varnode::isConstant(), and ghidra::Varnode::isWritten().

Referenced by applyOp().

◆ clone()

virtual Rule * ghidra::RuleConditionalMove::clone ( const ActionGroupList & grouplist ) const

inlinevirtual

Clone the Rule.

If this Rule is a member of one of the groups in the grouplist, this returns a clone of the Rule, otherwise NULL is returned.

Parameters

grouplist is the list of groups being cloned

Returns: the cloned Rule or NULL

Implements ghidra::Rule.

References ghidra::ActionGroupList::contains(), and ghidra::Rule::getGroup().

◆ constructBool()

Varnode * ghidra::RuleConditionalMove::constructBool	(	Varnode *	vn,
		PcodeOp *	insertop,
		vector< PcodeOp * > &	ops,
		Funcdata &	data
	)

staticprivate

Construct the expression after the merge.

Reproduce the bolean expression resulting in the given Varnode. Either reuse the existing Varnode or reconstruct it, making sure the expression does not depend on data in the branch.

Parameters

insertop	is point at which any reconstruction should be inserted
data	is the function being analyzed

Returns: the Varnode representing the boolean expression

References ghidra::CloneBlockOps::cloneExpression().

Referenced by applyOp().

◆ gatherExpression()

bool ghidra::RuleConditionalMove::gatherExpression	(	Varnode *	vn,
		vector< PcodeOp * > &	ops,
		FlowBlock *	root,
		FlowBlock *	branch
	)

staticprivate

Determine if the given expression can be propagated out of the condition.

If p-code ops contributing to the expression are contained in a conditional branch, they are collected in ops to later be pulled out of the branch (via duplication).

Parameters

vn	is the root of the given expression
ops	will hold the set of ops that need to be duplicated
root	is the block that performs the conditional branch
branch	is the conditional branch

Returns: true if the expression can be propagated

References ghidra::Varnode::getDef(), ghidra::PcodeOp::getEvalType(), ghidra::PcodeOp::getIn(), ghidra::PcodeOp::getParent(), ghidra::Varnode::isAddrTied(), ghidra::Varnode::isConstant(), ghidra::Varnode::isFree(), ghidra::Varnode::isWritten(), ghidra::Varnode::loneDescend(), ghidra::PcodeOp::numInput(), and ghidra::PcodeOp::special.

Referenced by applyOp().

◆ getOpList()

void ghidra::RuleConditionalMove::getOpList ( vector< uint4 > & oplist ) const

virtual

List of op codes this rule operates on.

Populate the given array with all possible OpCodes this Rule might apply to. By default, this method returns all possible OpCodes

Parameters

oplist is the array to populate

Reimplemented from ghidra::Rule.

References ghidra::CPUI_MULTIEQUAL.

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

/builds/appsec/reveng-binrw/ghidraplusplus/src/dec/ruleaction.hh
/builds/appsec/reveng-binrw/ghidraplusplus/src/dec/ruleaction.cc

Public Member Functions

Static Private Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ applyOp()

◆ checkBoolean()

◆ clone()

◆ constructBool()

◆ gatherExpression()

◆ getOpList()