Propagate conditional constants. More...

#include <coreaction.hh>

Inheritance diagram for ghidra::ActionConditionalConst:

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

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

virtual int4	apply (Funcdata &data)
	Make a single attempt to apply this Action. More...

Public Member Functions inherited from ghidra::Action
	Action (uint4 f, const string &nm, const string &g)
	Base constructor for an Action. More...

virtual	~Action (void)
	Destructor.

virtual void	printStatistics (ostream &s) const
	Dump statistics to stream. More...

int4	perform (Funcdata &data)
	Perform this action (if necessary) More...

bool	setBreakPoint (uint4 tp, const string &specify)
	Set a breakpoint on this action. More...

virtual void	clearBreakPoints (void)
	Clear all breakpoints set on this Action.

bool	setWarning (bool val, const string &specify)
	Set a warning on this action. More...

bool	disableRule (const string &specify)
	Disable a specific Rule within this. More...

bool	enableRule (const string &specify)
	Enable a specific Rule within this. More...

const string &	getName (void) const
	Get the Action's name.

const string &	getGroup (void) const
	Get the Action's group.

uint4	getStatus (void) const
	Get the current status of this Action.

uint4	getNumTests (void)
	Get the number of times apply() was invoked.

uint4	getNumApply (void)

virtual void	reset (Funcdata &data)
	Reset the Action for a new function. More...

virtual void	resetStats (void)
	Reset all the counts to zero. More...

virtual int4	print (ostream &s, int4 num, int4 depth) const
	Print a description of this Action to stream. More...

virtual void	printState (ostream &s) const
	Print status to stream. More...

virtual Action *	getSubAction (const string &specify)
	Retrieve a specific sub-action by name. More...

virtual Rule *	getSubRule (const string &specify)
	Retrieve a specific sub-rule by name. More...

Private Member Functions
void	handlePhiNodes (Varnode varVn, Varnode constVn, vector< PcodeOpNode > &phiNodeEdges, Funcdata &data)
	Replace MULTIEQUAL edges with constant if there is no alternate flow. More...

void	propagateConstant (Varnode varVn, Varnode constVn, FlowBlock *constBlock, bool useMultiequal, Funcdata &data)
	Replace reads of a given Varnode with a constant. More...

Static Private Member Functions
static void	clearMarks (const vector< PcodeOp *> &opList)
	Clear all marks on the given list of PcodeOps. More...

static void	collectReachable (Varnode vn, vector< PcodeOpNode > &phiNodeEdges, vector< PcodeOp > &reachable)
	Collect COPY, INDIRECT, and MULTIEQUAL ops reachable from the given Varnode, without going thru excised edges. More...

static bool	flowToAlternatePath (PcodeOp *op)
	Does the output of the given op reunite with the alternate flow. More...

static bool	flowTogether (const vector< PcodeOpNode > &edges, int4 i, vector< int4 > &result)
	Test if flow from a specific edge is disjoint from other edges. More...

static Varnode *	placeCopy (PcodeOp op, BlockBasic bl, Varnode *constVn, Funcdata &data)
	Place a COPY of a constant at the end of a basic block. More...

static void	placeMultipleConstants (vector< PcodeOpNode > &phiNodeEdges, vector< int4 > &marks, Varnode *constVn, Funcdata &data)
	Place a single COPY assignment shared by multiple MULTIEQUALs. More...

Additional Inherited Members
Public Types inherited from ghidra::Action
enum	ruleflags { rule_repeatapply = 4, rule_onceperfunc = 8, rule_oneactperfunc = 16, rule_debug = 32, rule_warnings_on = 64, rule_warnings_given = 128 }
	Boolean behavior properties governing this particular Action. More...

enum	statusflags { status_start =1, status_breakstarthit =2, status_repeat =4, status_mid =8, status_end =16, status_actionbreak =32 }
	Boolean properties describing the status of an action. More...

enum	breakflags { break_start = 1, tmpbreak_start = 2, break_action = 4, tmpbreak_action = 8 }
	Break points associated with an Action. More...

Protected Member Functions inherited from ghidra::Action
void	issueWarning (Architecture *glb)
	Warn that this Action has applied. More...

bool	checkStartBreak (void)
	Check start breakpoint. More...

bool	checkActionBreak (void)
	Check action breakpoint. More...

void	turnOnWarnings (void)
	Enable warnings for this Action.

void	turnOffWarnings (void)
	Disable warnings for this Action.

Protected Attributes inherited from ghidra::Action
int4	lcount
	Changes not including last call to apply()

int4	count
	Number of changes made by this action so far.

uint4	status
	Current status.

uint4	breakpoint
	Breakpoint properties.

uint4	flags
	Behavior properties.

uint4	count_tests
	Number of times apply() has been called.

uint4	count_apply
	Number of times apply() made changes.

string	name
	Name of the action.

string	basegroup
	Base group this action belongs to.

Detailed Description

Propagate conditional constants.

Member Function Documentation

◆ apply()

int4 ghidra::ActionConditionalConst::apply ( Funcdata & data )

virtual

Make a single attempt to apply this Action.

This is the main entry point for applying changes to a function that are specific to this Action. The method can inspect whatever it wants to decide if the Action does or does not apply. Changes are indicated by incrementing the count field.

Parameters

data	is the function to inspect/modify

Returns: 0 for a complete application, -1 for a partial completion (due to breakpoint)

Implements ghidra::Action.

References ghidra::PcodeOp::code(), ghidra::CPUI_BOOL_NEGATE, ghidra::CPUI_CBRANCH, ghidra::CPUI_INT_EQUAL, ghidra::CPUI_INT_NOTEQUAL, ghidra::Funcdata::getArch(), ghidra::Funcdata::getBasicBlocks(), ghidra::Varnode::getDef(), ghidra::PcodeOp::getIn(), ghidra::FlowBlock::getOut(), ghidra::AddrSpaceManager::getStackSpace(), ghidra::PcodeOp::isBooleanFlip(), ghidra::Varnode::isConstant(), ghidra::Varnode::isWritten(), ghidra::FlowBlock::lastOp(), ghidra::Funcdata::numHeritagePasses(), and ghidra::FlowBlock::restrictedByConditional().

◆ clearMarks()

void ghidra::ActionConditionalConst::clearMarks ( const vector< PcodeOp *> & opList )

staticprivate

Clear all marks on the given list of PcodeOps.

Parameters

opList is the given list

◆ clone()

virtual Action* ghidra::ActionConditionalConst::clone ( const ActionGroupList & grouplist ) const

inlinevirtual

Clone the Action.

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

Parameters

grouplist is the list of groups being cloned

Returns: the cloned Action or NULL

Implements ghidra::Action.

References ghidra::ActionStart::apply(), ghidra::ActionGroupList::contains(), and ghidra::Action::getGroup().

◆ collectReachable()

void ghidra::ActionConditionalConst::collectReachable	(	Varnode *	vn,
		vector< PcodeOpNode > &	phiNodeEdges,
		vector< PcodeOp *> &	reachable
	)

staticprivate

Collect COPY, INDIRECT, and MULTIEQUAL ops reachable from the given Varnode, without going thru excised edges.

If data-flow from the Varnode does not go through excised edges and reaches the op via other MULTIEQUALs, INDIRECTs, and COPYs, the op is put in a list, and its mark is set

Parameters

vn	is the given Varnode
phiNodeEdges	is the list of edges to excise
reachable	will hold the list ops that have been reached

References ghidra::Varnode::beginDescend(), ghidra::PcodeOp::code(), ghidra::CPUI_COPY, ghidra::CPUI_INDIRECT, ghidra::CPUI_MULTIEQUAL, ghidra::Varnode::endDescend(), ghidra::Varnode::getDef(), ghidra::PcodeOp::getIn(), ghidra::PcodeOp::isMark(), ghidra::Varnode::isWritten(), ghidra::PcodeOp::numInput(), ghidra::PcodeOp::setMark(), and ghidra::PcodeOpNode::slot.

◆ flowToAlternatePath()

bool ghidra::ActionConditionalConst::flowToAlternatePath ( PcodeOp * op )

staticprivate

Does the output of the given op reunite with the alternate flow.

Assuming alternate flows have been marked, follow the flow of the given op forward through MULTIEQUAL, INDIRECT, and COPY ops. If it hits the alternate flow, return true.

Parameters

op	is the given PcodeOp

Returns: true is there is an alternate path

References ghidra::Varnode::beginDescend(), ghidra::PcodeOp::code(), ghidra::CPUI_COPY, ghidra::CPUI_INDIRECT, ghidra::CPUI_MULTIEQUAL, ghidra::Varnode::endDescend(), ghidra::PcodeOp::getOut(), ghidra::PcodeOp::isMark(), ghidra::Varnode::isMark(), and ghidra::Varnode::setMark().

◆ flowTogether()

bool ghidra::ActionConditionalConst::flowTogether	(	const vector< PcodeOpNode > &	edges,
		int4	i,
		vector< int4 > &	result
	)

staticprivate

Test if flow from a specific edge is disjoint from other edges.

All MULTIEQUAL and COPY ops reachable from the edge are marked. If any other edge is in this marked set, mark both edges in the result set.

Parameters

edges	is the set of edges
i	is the index of the specific edge to test
result	is the array of marks to be returned

Returns: true if the selected edge flows together with any other edge

◆ handlePhiNodes()

void ghidra::ActionConditionalConst::handlePhiNodes	(	Varnode *	varVn,
		Varnode *	constVn,
		vector< PcodeOpNode > &	phiNodeEdges,
		Funcdata &	data
	)

private

Replace MULTIEQUAL edges with constant if there is no alternate flow.

A given Varnode is known to be constant along a set of MULTIEQUAL edges. If these edges are excised from the data-flow, and the output of a MULTIEQUAL does not rejoin with the Varnode along an alternate path, then that edge is replaced with a constant.

Parameters

varVn	is the given Varnode
constVn	is the constant to replace it with
phiNodeEdges	is the set of edges the Varnode is known to be constant on
data	is the function containing this data-flow

References ghidra::FlowBlock::getIn(), ghidra::PcodeOp::getParent(), and ghidra::Funcdata::opSetInput().

◆ placeCopy()

Varnode * ghidra::ActionConditionalConst::placeCopy	(	PcodeOp *	op,
		BlockBasic *	bl,
		Varnode *	constVn,
		Funcdata &	data
	)

staticprivate

Place a COPY of a constant at the end of a basic block.

Parameters

op	is an alternate "last" op
bl	is the basic block
constVn	is the constant to be assigned
data	is the function containing the block

Returns: the new output Varnode of the COPY

References ghidra::CPUI_COPY, ghidra::BlockBasic::endOp(), ghidra::PcodeOp::getAddr(), ghidra::PcodeOp::getBasicIter(), ghidra::Varnode::getSize(), ghidra::PcodeOp::isBranch(), ghidra::BlockBasic::lastOp(), ghidra::Funcdata::newOp(), ghidra::Funcdata::newUniqueOut(), ghidra::Funcdata::opInsert(), ghidra::Funcdata::opSetInput(), and ghidra::Funcdata::opSetOpcode().

◆ placeMultipleConstants()

void ghidra::ActionConditionalConst::placeMultipleConstants	(	vector< PcodeOpNode > &	phiNodeEdges,
		vector< int4 > &	marks,
		Varnode *	constVn,
		Funcdata &	data
	)

staticprivate

Place a single COPY assignment shared by multiple MULTIEQUALs.

Find the common ancestor block among all MULTIEQUALs marked as flowing together. Place a COPY assigning a constant at the bottom of this block. Replace all the input edge Varnodes on the MULTIEQUALs with the output of this COPY.

Parameters

phiNodeEdges	is the list of MULTIEQUALs and their incoming edges
marks	are the marks applied to the MULTIEQUALs (2 == flowtogether)
constVn	is the constant being assigned by the COPY
data	is the function

References ghidra::FlowBlock::findCommonBlock(), ghidra::FlowBlock::getIn(), ghidra::PcodeOp::getParent(), and ghidra::Funcdata::opSetInput().

◆ propagateConstant()

void ghidra::ActionConditionalConst::propagateConstant	(	Varnode *	varVn,
		Varnode *	constVn,
		FlowBlock *	constBlock,
		bool	useMultiequal,
		Funcdata &	data
	)

private

Replace reads of a given Varnode with a constant.

For each read op, check that is in or dominated by a specific block we known the Varnode is constant in.

Parameters

varVn	is the given Varnode
constVn	is the constant Varnode to replace with
constBlock	is the block which dominates ops reading the constant value
useMultiequal	is true if conditional constants can be applied to MULTIEQUAL ops
data	is the function being analyzed

References ghidra::Varnode::beginDescend(), ghidra::PcodeOp::code(), ghidra::CPUI_COPY, ghidra::CPUI_INDIRECT, ghidra::CPUI_MULTIEQUAL, ghidra::FlowBlock::dominates(), ghidra::Varnode::endDescend(), ghidra::Varnode::getAddr(), ghidra::PcodeOp::getIn(), ghidra::FlowBlock::getIn(), ghidra::PcodeOp::getOut(), ghidra::PcodeOp::getParent(), ghidra::PcodeOp::getSlot(), ghidra::Varnode::isAddrTied(), ghidra::PcodeOp::isMarker(), ghidra::Varnode::loneDescend(), ghidra::PcodeOp::numInput(), and ghidra::Funcdata::opSetInput().

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

coreaction.hh
coreaction.cc

Public Member Functions

Private Member Functions

Static Private Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ apply()

◆ clearMarks()

◆ clone()

◆ collectReachable()

◆ flowToAlternatePath()

◆ flowTogether()

◆ handlePhiNodes()

◆ placeCopy()

◆ placeMultipleConstants()

◆ propagateConstant()