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

#include <variable.hh>

Public Types
enum	{ flagsdirty = 1, namerepdirty = 2, typedirty = 4, coverdirty = 8, symboldirty = 0x10, copy_in1 = 0x20, copy_in2 = 0x40, type_finalized = 0x80, unmerged = 0x100, intersectdirty = 0x200, extendcoverdirty = 0x400 }
	Dirtiness flags for a HighVariable. More...

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

	~HighVariable (void)
	Destructor.

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

const Cover &	getCover (void) const
	Get cover data for this variable. More...

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

SymbolEntry *	getSymbolEntry (void) const

int4	getSymbolOffset (void) const
	Get the SymbolEntry mapping to this or null. More...

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

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

void	finalizeDatatype (Datatype *tp)
	Set a final datatype for this variable. More...

void	groupWith (int4 off, HighVariable *hi2)
	Put this and another HighVariable in the same intersection group. More...

void	establishGroupSymbolOffset (void)
	Transfer symbol offset of this to the VariableGroup. 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...

int4	getNumMergeClasses (void) const
	Get the number of speculative merges for this.

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.

bool	isProtoPartial (void) const
	Return true if this is a piece concatenated into a larger whole.

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	isUnmerged (void) const
	Return true if this has merge problems.

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.

void	encode (Encoder &encoder) const
	Encode this variable to stream as a <high> element. More...

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...

static int4	markExpression (Varnode vn, vector< HighVariable > &highList)
	Mark and collect variables in expression. 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	updateInternalCover (void) const
	(Re)derive the internal cover of this from the member Varnodes More...

void	updateCover (void) const
	(Re)derive the external cover of this, as a union of internal covers More...

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

void	updateSymbol (void) const
	(Re)derive the Symbol and offset for this from member Varnodes

void	setCopyIn1 (void) const
	Mark the existence of one COPY into this.

void	setCopyIn2 (void) const
	Mark the existence of two COPYs into this.

void	clearCopyIns (void) const
	Clear marks indicating COPYs into this.

bool	hasCopyIn1 (void) const
	Is there at least one COPY into this.

bool	hasCopyIn2 (void) const
	Is there at least two COPYs into this.

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

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

void	merge (HighVariable tv2, HighIntersectTest testCache, bool isspeculative)
	Merge with another HighVariable taking into account groups. More...

void	setSymbol (Varnode *vn) const
	Update Symbol information for this from the given member Varnode. More...

void	setSymbolReference (Symbol *sym, int4 off)
	Attach a reference to a Symbol to this. More...

void	transferPiece (HighVariable *tv2)
	Transfer ownership of another's VariablePiece to this.

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

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

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

void	symbolDirty (void) const
	Mark the symbol as dirty.

void	setUnmerged (void) const
	Mark this as having merge problems.

bool	isCoverDirty (void) const
	Is the cover returned by getCover() up-to-date. 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.

Varnode *	nameRepresentative
	The storage location used to generate a Symbol name.

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

VariablePiece *	piece
	Additional info about intersections with other pieces (if non-null)

Symbol *	symbol
	The Symbol this HighVariable is tied to.

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

Friends
class	Varnode

class	Merge

class	VariablePiece

class	HighIntersectTest

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.
namerepdirty	The name representative for the HighVariable is dirty.
typedirty	The data-type for the HighVariable is dirty.
coverdirty	The cover for the HighVariable is dirty.
symboldirty	The symbol attachment is dirty.
copy_in1	There exists at least 1 COPY into this HighVariable from other HighVariables.
copy_in2	There exists at least 2 COPYs into this HighVariable from other HighVariables.
type_finalized	Set if a final data-type is locked in and dirtying is disabled.
unmerged	Set if part of a multi-entry Symbol but did not get merged with other SymbolEntrys.
intersectdirty	Set if intersections with other HighVariables needs to be recomputed.
extendcoverdirty	Set if extended cover needs to be recomputed.

Constructor & Destructor Documentation

◆ HighVariable()

ghidra::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 ghidra::Varnode::getSymbolEntry(), and ghidra::Varnode::setHigh().

Member Function Documentation

◆ compareJustLoc()

bool ghidra::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 ghidra::Varnode::getAddr().

◆ compareName()

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

◆ coverDirty()

void ghidra::HighVariable::coverDirty ( void ) const

inlineprivate

Mark the cover as dirty.

The internal cover is marked as dirty. If this is a piece of a VariableGroup, it and all the other HighVariables it intersects with are marked as having a dirty extended cover.

Referenced by ghidra::Merge::inflate().

◆ encode()

void ghidra::HighVariable::encode ( Encoder & encoder ) const

Encode this variable to stream as a <high> element.

Parameters

encoder is the stream encoder

References ghidra::Encoder::closeElement(), ghidra::Symbol::function_parameter, ghidra::Varnode::getCreateIndex(), ghidra::Encoder::openElement(), ghidra::Encoder::writeBool(), ghidra::Encoder::writeSignedInteger(), ghidra::Encoder::writeString(), and ghidra::Encoder::writeUnsignedInteger().

Referenced by ghidra::Funcdata::encodeHigh().

◆ establishGroupSymbolOffset()

void ghidra::HighVariable::establishGroupSymbolOffset ( void )

Transfer symbol offset of this to the VariableGroup.

If this is part of a larger group and has had its symboloffset set, it can be used to calculate the symboloffset of other HighVariables in the same group, by writing it to the common VariableGroup object.

References ghidra::VariableGroup::setSymbolOffset().

Referenced by ghidra::Funcdata::linkProtoPartial().

◆ finalizeDatatype()

void ghidra::HighVariable::finalizeDatatype ( Datatype * tp )

Set a final datatype for this variable.

The data-type its dirtying mechanism is disabled. The data-type will not change, unless this method is called again.

Parameters

tp	is the data-type to set

References ghidra::Datatype::getMetatype(), ghidra::TYPE_PARTIALUNION, ghidra::TYPE_STRUCT, and ghidra::TYPE_UNION.

Referenced by ghidra::Funcdata::syncVarnodesWithSymbol().

◆ getCover()

const Cover & ghidra::HighVariable::getCover ( void ) const

inline

Get cover data for this variable.

The returns the internal cover unless this is part of a VariableGroup, in which case the extended cover is returned.

Returns: the cover associated with this variable

Referenced by ghidra::HighIntersectTest::blockIntersection(), ghidra::Merge::compareHighByBlock(), and ghidra::HighIntersectTest::intersection().

◆ getInputVarnode()

Varnode * ghidra::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

Referenced by ghidra::Merge::mergeTestAdjacent().

◆ getNameRepresentative()

Varnode * ghidra::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

Referenced by ghidra::Funcdata::linkProtoPartial(), ghidra::ActionNameVars::linkSymbols(), and ghidra::PrintLanguage::pushSymbolDetail().

◆ getSymbolEntry()

SymbolEntry * ghidra::HighVariable::getSymbolEntry ( void ) const

Assuming there is a Symbol attached to this, run through the Varnode members until we find one with a SymbolEntry corresponding to the Symbol and return it.

Returns: the SymbolEntry that mapped the Symbol to this or null if no Symbol is attached

References ghidra::SymbolEntry::getSymbol().

Referenced by ghidra::PrintC::pushSymbol().

◆ getSymbolOffset()

int4 ghidra::HighVariable::getSymbolOffset ( void ) const

inline

Get the SymbolEntry mapping to this or null.

Get the Symbol offset associated with this

Referenced by ghidra::ActionNameVars::linkSymbols(), ghidra::Merge::mergeTestRequired(), ghidra::PrintC::opPtrsub(), ghidra::PrintC::opSubpiece(), and ghidra::PrintLanguage::pushSymbolDetail().

◆ getTiedVarnode()

Varnode * ghidra::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

Referenced by ghidra::MapState::gatherHighs(), and ghidra::Merge::mergeTestRequired().

◆ getTypeRepresentative()

Varnode * ghidra::HighVariable::getTypeRepresentative ( void ) const

Get a member Varnode with the strongest data-type.

Find the member Varnode with the most specialized data-type, handling bool specially. Boolean data-types are specialized in the data-type lattice, but not all byte values are boolean values. Within the Varnode/PcodeOp tree, the bool data-type can only propagate to a Varnode if it is verified to only take the boolean values 0 and 1. Since the data-type representative represents the type of all instances, if any instance is not boolean, then the HighVariable cannot be boolean, even though bool is more specialized. This method uses Datatype::typeOrderBool() to implement the special handling.

Returns: the representative member

References ghidra::Varnode::getType(), ghidra::Varnode::isTypeLock(), and ghidra::Datatype::typeOrderBool().

◆ groupWith()

void ghidra::HighVariable::groupWith	(	int4	off,
		HighVariable *	hi2
	)

Put this and another HighVariable in the same intersection group.

If one of the HighVariables is already in a group, the other HighVariable is added to this group.

Parameters

off	is the relative byte offset of this with the other HighVariable
hi2	is the other HighVariable

References ghidra::VariableGroup::combineGroups(), ghidra::VariablePiece::getGroup(), ghidra::VariablePiece::getOffset(), highflags, ghidra::VariablePiece::markIntersectionDirty(), and piece.

Referenced by ghidra::Merge::groupPartialRoot(), and ghidra::Merge::mergeAddrTied().

◆ hasCover()

bool ghidra::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 ghidra::Varnode::annotation, ghidra::Varnode::constant, and ghidra::Varnode::insert.

Referenced by ghidra::Merge::mergeTest().

◆ hasName()

bool ghidra::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 ghidra::Varnode::hasCover(), ghidra::Varnode::isIllegalInput(), ghidra::Varnode::isImplied(), ghidra::Varnode::isIndirectOnly(), and ghidra::Varnode::isSpacebase().

Referenced by ghidra::ActionNameVars::linkSymbols().

◆ instanceIndex()

int4 ghidra::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

◆ isCoverDirty()

bool ghidra::HighVariable::isCoverDirty ( void ) const

inlineprivate

Is the cover returned by getCover() up-to-date.

The cover could either by the internal one or the extended one if this is part of a Variable Group.

Returns: true if the cover needs to be recomputed.

Referenced by ghidra::HighIntersectTest::updateHigh().

◆ markExpression()

int4 ghidra::HighVariable::markExpression	(	Varnode *	vn,
		vector< HighVariable *> &	highList
	)

static

Mark and collect variables in expression.

Given a Varnode at the root of an expression, we collect all the explicit HighVariables involved in the expression. This should only be run after explicit and implicit properties have been computed on Varnodes. The expression is traced back from the root until explicit Varnodes are encountered; then their HighVariable is marked and added to the list. The routine returns a value based on PcodeOps encountered in the expression:

1 for call instructions
2 for LOAD instructions
3 for both call and LOAD
0 for no calls or LOADS

Parameters

vn	is the given root Varnode of the expression
highList	will hold the collected HighVariables

Returns: a value based on call and LOAD instructions in the expression

References ghidra::PcodeOp::code(), ghidra::Varnode::copyShadow(), ghidra::CPUI_LOAD, ghidra::Varnode::getCover(), ghidra::Varnode::getDef(), ghidra::Varnode::getHigh(), ghidra::Cover::intersect(), ghidra::Varnode::isAnnotation(), ghidra::PcodeOp::isCall(), ghidra::Varnode::isExplicit(), isMark(), ghidra::Varnode::isWritten(), ghidra::Cover::merge(), and setMark().

Referenced by ghidra::Funcdata::moveRespectingCover().

◆ merge()

void ghidra::HighVariable::merge	(	HighVariable *	tv2,
		HighIntersectTest *	testCache,
		bool	isspeculative
	)

private

Merge with another HighVariable taking into account groups.

The HighVariables are merged internally as with mergeInternal. If this is part of a VariableGroup, extended covers of the group may be affected. If both HighVariables are part of separate groups, the groups are combined into one, which may induce additional HighVariable pairs within the group to be merged. In all cases, the other HighVariable is deleted.

Parameters

tv2	is the other HighVariable to merge into this
testCache	if non-null is a cache of intersection tests that must be updated to reflect the merge
isspeculative	is true to keep the new members in separate merge classes

References mergeInternal(), ghidra::HighIntersectTest::moveIntersectTests(), and piece.

Referenced by ghidra::Merge::buildDominantCopy(), and ghidra::Merge::merge().

◆ mergeInternal()

void ghidra::HighVariable::mergeInternal	(	HighVariable *	tv2,
		bool	isspeculative
	)

private

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 ghidra::Varnode::getMergeGroup(), highflags, inst, internalCover, numMergeClasses, ghidra::Varnode::setHigh(), symbol, and symboloffset.

Referenced by merge().

◆ printCover()

void ghidra::HighVariable::printCover ( ostream & s ) const

inline

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

Parameters

s	is the output stream

References coverdirty, and ghidra::Cover::print().

Referenced by ghidra::IfcPrintCover::execute(), and ghidra::IfcVarnodehighCover::execute().

◆ printInfo()

void ghidra::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 ghidra::Varnode::getMergeGroup(), and ghidra::Varnode::printInfo().

Referenced by ghidra::IfcPrintHigh::execute(), and ghidra::IfcPrintVarnode::execute().

◆ remove()

void ghidra::HighVariable::remove ( Varnode * vn )

private

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 ghidra::Varnode::getSymbolEntry().

Referenced by ghidra::Merge::buildDominantCopy(), and ghidra::Varnode::~Varnode().

◆ setSymbol()

void ghidra::HighVariable::setSymbol ( Varnode * vn ) const

private

Update Symbol information for this from the given member Varnode.

The given Varnode must be a member and must have a non-null SymbolEntry.

References ghidra::Symbol::equate, ghidra::SymbolEntry::getAddr(), ghidra::Varnode::getAddr(), ghidra::Symbol::getName(), ghidra::SymbolEntry::getOffset(), ghidra::Varnode::getSize(), ghidra::SymbolEntry::getSymbol(), ghidra::Varnode::getSymbolEntry(), ghidra::SymbolEntry::isDynamic(), ghidra::SymbolEntry::isPiece(), ghidra::Varnode::isProtoPartial(), ghidra::Address::overlapJoin(), and ghidra::TYPE_PARTIALUNION.

◆ setSymbolReference()

void ghidra::HighVariable::setSymbolReference	(	Symbol *	sym,
		int4	off
	)

private

Attach a reference to a Symbol to this.

Link information to this from a Symbol that is not attached to a member Varnode. This only works for a HighVariable with a constant member Varnode. This used when there is a constant address reference to the Symbol and the Varnode holds the reference, not the actual value of the Symbol.

Parameters

sym	is the given Symbol to attach
off	is the byte offset into the Symbol of the reference

◆ updateCover()

void ghidra::HighVariable::updateCover ( void ) const

private

(Re)derive the external cover of this, as a union of internal covers

This is only called by the Merge class which knows when to call it properly.

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

◆ updateFlags()

void ghidra::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 ghidra::Varnode::directwrite, ghidra::Varnode::mark, and ghidra::Varnode::typelock.

◆ updateInternalCover()

void ghidra::HighVariable::updateInternalCover ( void ) const

private

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

Only update if the cover is marked as dirty. Merge the covers of all Varnode instances.

Referenced by ghidra::VariablePiece::updateCover().

◆ updateType()

void ghidra::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 ghidra::Datatype::getMetatype(), ghidra::Varnode::getType(), ghidra::Varnode::isTypeLock(), ghidra::TYPE_PARTIALUNION, ghidra::TYPE_STRUCT, ghidra::TYPE_UNION, and ghidra::Varnode::typelock.

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()

◆ coverDirty()

◆ encode()

◆ establishGroupSymbolOffset()

◆ finalizeDatatype()

◆ getCover()

◆ getInputVarnode()

◆ getNameRepresentative()

◆ getSymbolEntry()

◆ getSymbolOffset()

◆ getTiedVarnode()

◆ getTypeRepresentative()

◆ groupWith()

◆ hasCover()

◆ hasName()

◆ instanceIndex()

◆ isCoverDirty()

◆ markExpression()

◆ merge()

◆ mergeInternal()

◆ printCover()

◆ printInfo()

◆ remove()

◆ setSymbol()

◆ setSymbolReference()

◆ updateCover()

◆ updateFlags()

◆ updateInternalCover()

◆ updateType()