Find explicit Varnodes: Varnodes that have an explicit token representing them in the output. More...

#include <coreaction.hh>

Inheritance diagram for ActionMarkExplicit:

Classes
struct	OpStackElement
	This class holds a single entry in a stack used to traverse Varnode expressions. More...

Public Member Functions
	ActionMarkExplicit (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 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...

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 void	saveXml (ostream &s) const
	Save specifics of this action to stream.

virtual void	restoreXml (const Element el, Funcdata fd)
	Load specifics of action from XML.

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...

Static Private Member Functions
static int4	baseExplicit (Varnode *vn, int4 maxref)
	Make initial determination if a Varnode should be explicit. More...

static int4	multipleInteraction (vector< Varnode * > &multlist)
	Find multiple descendant chains. More...

static void	processMultiplier (Varnode *vn, int4 max)
	For a given multi-descendant Varnode, decide if it should be explicit. More...

static void	checkNewToConstructor (Funcdata &data, Varnode *vn)
	Set special properties on output of CPUI_NEW. More...

Additional Inherited Members
Public Types inherited from 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 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 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

Find explicit Varnodes: Varnodes that have an explicit token representing them in the output.

In the final output of the syntax tree as source code, all variables are characterized as either

explicit, having a specific identifier in the source code, or
implied, an intermediate result of an expression with no specific identifier

This Action does preliminary scanning of Varnodes to determine which should be explicit in the final output. Basically, if there is symbol information associated, the possibility of aliasing, or if there are too many reads of a Varnode, it should be considered explicit.

Member Function Documentation

◆ apply()

int4 ActionMarkExplicit::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 Action.

References baseExplicit(), Funcdata::beginDef(), checkNewToConstructor(), Action::count, Funcdata::getArch(), Varnode::isMark(), Architecture::max_implied_ref, Architecture::max_term_duplication, multipleInteraction(), processMultiplier(), Varnode::setExplicit(), and Varnode::setMark().

◆ baseExplicit()

int4 ActionMarkExplicit::baseExplicit	(	Varnode *	vn,
		int4	maxref
	)

staticprivate

Make initial determination if a Varnode should be explicit.

If the given Varnode is defined by CPUI_NEW, return -2 indicating it should be explicit and that it needs special printing.

Parameters

vn	is the given Varnode
maxref	is the maximum number of references to consider before forcing explicitness

Returns: -1 if given Varnode should be marked explicit, the number of descendants otherwise

References Varnode::beginDescend(), PcodeOp::code(), Varnode::contains(), CPUI_INT_ZEXT, CPUI_NEW, CPUI_PIECE, CPUI_PTRSUB, CPUI_SUBPIECE, Varnode::endDescend(), Varnode::getDef(), Varnode::getHigh(), PcodeOp::getIn(), Varnode::getOffset(), PcodeOp::getOut(), Varnode::hasNoDescend(), Varnode::isAddrTied(), PcodeOp::isCall(), Varnode::isConstant(), Varnode::isInput(), Varnode::isMapped(), PcodeOp::isMarker(), Varnode::isSpacebase(), PcodeOp::numInput(), HighVariable::numInstances(), and Varnode::overlap().

Referenced by apply().

◆ checkNewToConstructor()

void ActionMarkExplicit::checkNewToConstructor	(	Funcdata &	data,
		Varnode *	vn
	)

staticprivate

Set special properties on output of CPUI_NEW.

Assume vn is produced via a CPUI_NEW operation. If it is immediately fed to a constructor, set special printing flags on the Varnode.

Parameters

data	is the function being analyzed
vn	is the given Varnode

References Varnode::beginDescend(), PcodeOp::code(), CPUI_CALLIND, Varnode::endDescend(), Varnode::getDef(), PcodeOp::getIn(), SeqNum::getOrder(), PcodeOp::getOut(), PcodeOp::getParent(), PcodeOp::getSeqNum(), PcodeOp::isCall(), Varnode::isWritten(), PcodeOp::nonprinting, PcodeOp::numInput(), Funcdata::opSetFlag(), and PcodeOp::special_print.

Referenced by apply().

◆ clone()

virtual Action* ActionMarkExplicit::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 Action.

References ActionMarkExplicit(), ActionGroupList::contains(), and Action::getGroup().

◆ multipleInteraction()

int4 ActionMarkExplicit::multipleInteraction ( vector< Varnode * > & multlist )

staticprivate

Find multiple descendant chains.

Look for certain situations where one Varnode with multiple descendants has one descendant who also has multiple descendants. This routine is handed the list of Varnodes with multiple descendants; These all must already have their mark set. For the situations we can find with one flowing into another, mark the top Varnode as explicit.

Parameters

multlist is the list Varnodes with multiple descendants

Returns: the number Varnodes that were marked as explicit

References Varnode::clearImplied(), Varnode::clearMark(), PcodeOp::code(), CPUI_COPY, CPUI_INT_SEXT, CPUI_INT_ZEXT, CPUI_PTRADD, Varnode::getDef(), PcodeOp::getIn(), PcodeOp::isBoolOutput(), Varnode::isMark(), Varnode::isWritten(), PcodeOp::numInput(), and Varnode::setExplicit().

Referenced by apply().

◆ processMultiplier()

void ActionMarkExplicit::processMultiplier	(	Varnode *	vn,
		int4	max
	)

staticprivate

For a given multi-descendant Varnode, decide if it should be explicit.

Count the number of terms in the expression making up vn. If there are more than max terms, mark vn as explicit. The given Varnode is already assumed to have multiple descendants. We do a depth first traversal along op inputs, to recursively calculate the number of explicit terms in an expression.

Parameters

vn	is the given Varnode
max	is the maximum number of terms to allow

References Varnode::clearImplied(), Varnode::getDef(), PcodeOp::getIn(), Varnode::isExplicit(), Varnode::isMark(), Varnode::isSpacebase(), Varnode::isWritten(), and Varnode::setExplicit().

Referenced by apply().

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

coreaction.hh
coreaction.cc

Classes

Public Member Functions

Static Private Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ apply()

◆ baseExplicit()

◆ checkNewToConstructor()

◆ clone()

◆ multipleInteraction()

◆ processMultiplier()