A high-level variable modeled as a list of low-level variables, each written once. More...

#include <variable.hh>

Public Types
enum	{ flagsdirty = 1, typedirty = 2, coverdirty = 4 }
	Dirtiness flags for a HighVariable. More...

Public Member Functions
	HighVariable (Varnode *vn)
	Construct a HighVariable with a single member Varnode. More...

Datatype *	getType (void) const
	Get the data-type.

void	setSymbol (Symbol *sym, int4 off) const
	Set the Symbol associated with this HighVariable. More...

Symbol *	getSymbol (void) const
	Get the Symbol associated with this.

int4	getSymbolOffset (void) const
	Get the Symbol offset associated with this.

int4	numInstances (void) const
	Get the number of member Varnodes this has.

Varnode *	getInstance (int4 i) const
	Get the i-th member Varnode.

void	flagsDirty (void) const
	Mark the boolean properties as dirty.

void	coverDirty (void) const
	Mark the cover as dirty.

void	typeDirty (void) const
	Mark the data-type as dirty.

void	remove (Varnode *vn)
	Remove a member Varnode from this. More...

void	printCover (ostream &s) const
	Print details of the cover for this (for debug purposes) More...

void	printInfo (ostream &s) const
	Print information about this HighVariable to stream. More...

bool	hasName (void) const
	Check if this HighVariable can be named. More...

Varnode *	getTiedVarnode (void) const
	Find the first address tied member Varnode. More...

Varnode *	getInputVarnode (void) const
	Find (the) input member Varnode. More...

Varnode *	getTypeRepresentative (void) const
	Get a member Varnode with the strongest data-type. More...

Varnode *	getNameRepresentative (void) const
	Get a member Varnode that dictates the naming of this HighVariable. More...

void	merge (HighVariable *tv2, bool isspeculative)
	Merge another HighVariable into this. More...

bool	isMapped (void) const
	Return true if this is mapped.

bool	isPersist (void) const
	Return true if this is a global variable.

bool	isAddrTied (void) const
	Return true if this is address ties.

bool	isInput (void) const
	Return true if this is an input variable.

bool	isImplied (void) const
	Return true if this is an implied variable.

bool	isSpacebase (void) const
	Return true if this is a spacebase.

bool	isConstant (void) const
	Return true if this is a constant.

bool	isUnaffected (void) const
	Return true if this is an unaffected register.

bool	isExtraOut (void) const
	Return true if this is an extra output.

void	setMark (void) const
	Set the mark on this variable.

void	clearMark (void) const
	Clear the mark on this variable.

bool	isMark (void) const
	Return true if this is marked.

bool	hasCover (void) const
	Determine if this HighVariable has an associated cover. More...

bool	isUnattached (void) const
	Return true if this has no member Varnode.

bool	isTypeLock (void) const
	Return true if this is typelocked.

bool	isNameLock (void) const
	Return true if this is namelocked.

Static Public Member Functions
static bool	compareName (Varnode vn1, Varnode vn2)
	Determine which given Varnode is most nameable. More...

static bool	compareJustLoc (const Varnode a, const Varnode b)
	Compare based on storage location. More...

Private Member Functions
int4	instanceIndex (const Varnode *vn) const
	Find the index of a specific Varnode member. More...

void	updateFlags (void) const
	(Re)derive boolean properties of this from the member Varnodes More...

void	updateCover (void) const
	(Re)derive the cover of this from the member Varnodes More...

void	updateType (void) const
	(Re)derive the data-type for this from the member Varnodes More...

Private Attributes
vector< Varnode * >	inst
	The member Varnode objects making up this HighVariable.

int4	numMergeClasses
	Number of different speculative merge classes in this.

uint4	highflags
	Dirtiness flags.

uint4	flags
	Boolean properties inherited from Varnode members.

Datatype *	type
	The data-type for this.

Cover	wholecover
	The ranges of code addresses covered by this HighVariable.

Symbol *	symbol
	The Symbol this HighVariable is tied to.

int4	symboloffset
	-1=perfect symbol match >=0, offset

Friends
class	Merge

Detailed Description

A high-level variable modeled as a list of low-level variables, each written once.

In the Static Single Assignment (SSA) representation of a function's data-flow, the Varnode object represents a variable node. This is a low-level variable: it is written to at most once, and there is 1 or more reads. A high-level variable, in the source language may be written to multiple times. We model this idea as a list of Varnode objects, where a different Varnode holds the value of the variable for different parts of the code. The range(s) of code for which a single Varnode holds the high-level variable's value is the cover or range of that Varnode and is modeled by the class Cover. Within a high-level variable, HighVariable, the covers of member Varnode objects should not intersect, as that represents the variable holding two or more different values at the same place in the code. The HighVariable inherits a cover which is the union of the covers of its Varnodes.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

Dirtiness flags for a HighVariable.

The HighVariable inherits its Cover, its data-type, and other boolean properties from its Varnodes. The object holds these explicitly, but the values may become stale as the data-flow transforms. So we keep track of when these inherited values are dirty

Enumerator
flagsdirty	Boolean properties for the HighVariable are dirty.
typedirty	The data-type for the HighVariable is dirty.
coverdirty	The cover for the HighVariable is dirty.

Constructor & Destructor Documentation

◆ HighVariable()

HighVariable::HighVariable ( Varnode * vn )

Construct a HighVariable with a single member Varnode.

The new instance starts off with no associate Symbol and all properties marked as dirty.

Parameters

vn	is the single Varnode member

References coverdirty, flags, flagsdirty, highflags, inst, numMergeClasses, Varnode::setHigh(), symbol, symboloffset, type, and typedirty.

Member Function Documentation

◆ compareJustLoc()

bool HighVariable::compareJustLoc	(	const Varnode *	a,
		const Varnode *	b
	)

static

Compare based on storage location.

Compare two Varnode objects based just on their storage address

Parameters

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

Returns: true if the first Varnode should be ordered before the second

References Varnode::getAddr().

Referenced by merge(), and remove().

◆ compareName()

bool HighVariable::compareName	(	Varnode *	vn1,
		Varnode *	vn2
	)

static

Determine which given Varnode is most nameable.

Given two Varnode (members), sort them based on naming properties:

A Varnode with an assigned name is preferred
An unaffected Varnode is preferred
A global Varnode is preferred
An input Varnode is preferred
An address tied Varnode is preferred
A non-temporary Varnode is preferred
A written Varnode is preferred
An earlier Varnode is preferred

Returns: true if the second Varnode's name would override the first's

References Varnode::getDef(), Varnode::getSpace(), PcodeOp::getTime(), AddrSpace::getType(), IPTR_INTERNAL, Varnode::isAddrTied(), Varnode::isInput(), Varnode::isNameLock(), Varnode::isPersist(), Varnode::isUnaffected(), and Varnode::isWritten().

Referenced by getNameRepresentative().

◆ getInputVarnode()

Varnode * HighVariable::getInputVarnode ( void ) const

Find (the) input member Varnode.

This should only be called if isInput() returns true. If there is no input member, this will throw an exception.

Returns: the input Varnode member

References inst, and isInput().

Referenced by hasName(), and Merge::mergeTestAdjacent().

◆ getNameRepresentative()

Varnode * HighVariable::getNameRepresentative ( void ) const

Get a member Varnode that dictates the naming of this HighVariable.

Members are scored based the properties that are most dominating in choosing a name.

Returns: the highest scoring Varnode member

References compareName(), and inst.

Referenced by ActionNameVars::apply(), PrintLanguage::pushVnExplicit(), PrintLanguage::pushVnLHS(), and Funcdata::saveXmlHigh().

◆ getTiedVarnode()

Varnode * HighVariable::getTiedVarnode ( void ) const

Find the first address tied member Varnode.

This should only be called if isAddrTied() returns true. If there is no address tied member, this will throw an exception.

Returns: the first address tied member

References inst, and isAddrTied().

Referenced by ActionCopyMarker::apply(), and Merge::mergeTestRequired().

◆ getTypeRepresentative()

Varnode * HighVariable::getTypeRepresentative ( void ) const

Get a member Varnode with the strongest data-type.

Using Datatype::typeOrder, find the member Varnode with the most specific data-type.

Returns: the representative member

References Varnode::getType(), inst, Varnode::isTypeLock(), and Datatype::typeOrder().

Referenced by updateType().

◆ hasCover()

bool HighVariable::hasCover ( void ) const

inline

Determine if this HighVariable has an associated cover.

Constant and annotation variables do not have a cover

Returns: true if this has a cover

References Varnode::annotation, Varnode::constant, flags, Varnode::insert, and updateFlags().

Referenced by Merge::mergeTest(), and updateCover().

◆ hasName()

bool HighVariable::hasName ( void ) const

Check if this HighVariable can be named.

All Varnode objects are assigned a HighVariable, including those that don't get names like indirect variables, constants, and annotations. Determine if this, as inherited from its member Varnodes, can have a name.

Returns: true if this can have a name

References getInputVarnode(), Varnode::hasCover(), inst, Varnode::isIllegalInput(), Varnode::isImplied(), Varnode::isIndirectOnly(), isInput(), Varnode::isSpacebase(), and isUnaffected().

Referenced by ActionNameVars::apply().

◆ instanceIndex()

int4 HighVariable::instanceIndex ( const Varnode * vn ) const

private

Find the index of a specific Varnode member.

Find the index, for use with getInstance(), that will retrieve the given Varnode member

Parameters

vn	is the given Varnode member

Returns: the index of the member or -1 if it is not a member

References inst.

◆ merge()

void HighVariable::merge	(	HighVariable *	tv2,
		bool	isspeculative
	)

Merge another HighVariable into this.

The lists of members are merged and the other HighVariable is deleted.

Parameters

tv2	is the other HighVariable to merge into this
isspeculative	is true to keep the new members in separate merge classes

References compareJustLoc(), coverdirty, flagsdirty, Varnode::getMergeGroup(), highflags, inst, Cover::merge(), numMergeClasses, Varnode::setHigh(), typedirty, and wholecover.

Referenced by Merge::merge().

◆ printCover()

void HighVariable::printCover ( ostream & s ) const

inline

Print details of the cover for this (for debug purposes)

Parameters

s	is the output stream

References coverdirty, highflags, Cover::print(), and wholecover.

◆ printInfo()

void HighVariable::printInfo ( ostream & s ) const

Print information about this HighVariable to stream.

This is generally used for debug purposes.

Parameters

s	is the output stream

References Varnode::getMergeGroup(), Symbol::getName(), inst, Varnode::printInfo(), Datatype::printRaw(), symbol, symboloffset, type, and updateType().

◆ remove()

void HighVariable::remove ( Varnode * vn )

Remove a member Varnode from this.

Search for the given Varnode and cut it out of the list, marking all properties as dirty.

Parameters

vn	is the given Varnode member to remove

References compareJustLoc(), coverdirty, flagsdirty, highflags, inst, and typedirty.

Referenced by Varnode::~Varnode().

◆ setSymbol()

void HighVariable::setSymbol	(	Symbol *	sym,
		int4	off
	)		const

inline

Set the Symbol associated with this HighVariable.

This HighVariable does not need to be associated with the whole symbol. It can be associated with a part, like a sub-field, if the size of the member Varnodes and the Symbol don't match. In this case a non-zero offset may be passed in with the Symbol to indicate what part is represented by the this.

Parameters

sym	is the Symbol to associate with this
off	is the offset in bytes, relative to the Symbol, where this HighVariable starts

References symbol, and symboloffset.

Referenced by ActionDynamicSymbols::apply(), Funcdata::buildDynamicSymbol(), and Funcdata::linkSymbol().

◆ updateCover()

void HighVariable::updateCover ( void ) const

private

(Re)derive the cover of this from the member Varnodes

Only update if the cover is marked as dirty. Merge the covers of all Varnode instances. This is only called by the Merge class which knows when to call it properly.

References Cover::clear(), coverdirty, hasCover(), highflags, inst, Cover::merge(), and wholecover.

Referenced by Merge::merge(), and Merge::updateHigh().

◆ updateFlags()

void HighVariable::updateFlags ( void ) const

private

(Re)derive boolean properties of this from the member Varnodes

Only update if flags are marked as dirty. Generally if any member Varnode possesses the property, this HighVariable should inherit it. The Varnode::typelock field is not set here, but in updateType().

References Varnode::directwrite, flags, flagsdirty, highflags, inst, Varnode::mark, and Varnode::typelock.

Referenced by hasCover(), isAddrTied(), isConstant(), isExtraOut(), isImplied(), isInput(), isMapped(), isNameLock(), isPersist(), isSpacebase(), and isUnaffected().

◆ updateType()

void HighVariable::updateType ( void ) const

private

(Re)derive the data-type for this from the member Varnodes

Only update if the data-type is marked as dirty. Get the most locked, most specific data-type from member Varnode objects.

References flags, Varnode::getType(), getTypeRepresentative(), highflags, Varnode::isTypeLock(), type, typedirty, and Varnode::typelock.

Referenced by getType(), isTypeLock(), and printInfo().

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

variable.hh
variable.cc

Public Types

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Friends

Detailed Description

Member Enumeration Documentation

◆ anonymous enum

Constructor & Destructor Documentation

◆ HighVariable()

Member Function Documentation

◆ compareJustLoc()

◆ compareName()

◆ getInputVarnode()

◆ getNameRepresentative()

◆ getTiedVarnode()

◆ getTypeRepresentative()

◆ hasCover()

◆ hasName()

◆ instanceIndex()

◆ merge()

◆ printCover()

◆ printInfo()

◆ remove()

◆ setSymbol()

◆ updateCover()

◆ updateFlags()

◆ updateType()