Package ghidra.program.model.pcode

Class Varnode

java.lang.Object

ghidra.program.model.pcode.Varnode

Direct Known Subclasses:

VarnodeAST, VarnodeOperation

public class Varnode
extends java.lang.Object

Rawest possible Varnode. Just a variable location and size, not part of a syntax tree. A raw varnode is said to be free, it is not attached to any variable.

Constructor Summary

Constructors

Constructor	Description
Varnode(Address a, int sz)
Varnode(Address a, int sz, int symbolKey)

Method Summary

Modifier and Type	Method	Description
static void	appendSpaceOffset(java.lang.StringBuilder buf, Address addr)
void	buildXML(java.lang.StringBuilder buf)
static java.lang.String	buildXMLAddress(Address addr)	Convert an address into an XML document.
static java.lang.String	buildXMLAddress(Varnode[] varnodes, int logicalsize)	Convert a varnode array into an XML document.
static void	buildXMLAddress(java.lang.StringBuilder resBuf, Address addr, int size)	Build an XML document representation of a varnode with the given address and size.
boolean	contains(Address address)	Determine if this varnode contains the specified address
boolean	equals(java.lang.Object o)
Address	getAddress()
PcodeOp	getDef()
java.util.Iterator<PcodeOp>	getDescendants()
HighVariable	getHigh()
PcodeOp	getLoneDescend()	If there is only one PcodeOp taking this varnode as input, return it.
short	getMergeGroup()
long	getOffset()
Address	getPCAddress()	Get the address where this varnode is defined or NO_ADDRESS if this varnode is an input
int	getSize()
int	getSpace()
long	getWordOffset()	Returns the word offset into the address space this is defined within The word size is defined in the Language's .slaspec file with the "WORDSIZE" argument when DEFINEing a memory SPACE (capitalization is for emphasis; the directives are actually lowercase).
int	hashCode()
boolean	intersects(AddressSetView set)	Determine if this varnode intersects the specified address set
boolean	intersects(Varnode varnode)	Determine if this varnode intersects another varnode.
boolean	isAddress()
boolean	isAddrTied()
boolean	isConstant()
boolean	isFree()
boolean	isHash()
boolean	isInput()
boolean	isPersistant()
boolean	isRegister()
boolean	isUnaffected()
boolean	isUnique()
static Varnode	readXML(XmlPullParser parser, PcodeFactory factory)	Build a varnode from a SAX parse tree node
static Address	readXMLAddress(XmlElement el, AddressFactory addrFactory)	Create an address from a SAX parse tree node.
static Address	readXMLAddress(java.lang.String addrstring, AddressFactory addrfactory, AddressSpace refSpace)	Parse an XML containing an address.
static Address	readXMLAddress(java.lang.String localName, org.xml.sax.Attributes attr, AddressFactory addrFactory)
java.lang.String	toString()
java.lang.String	toString(Language language)	Convert this varnode to an alternate String representation based on a specified language.
void	trim()	Trim a varnode in a constant space to the correct starting offset.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Varnode

public Varnode(Address a,
               int sz)

Parameters:

a - location varnode attached to

sz - size of varnode

Varnode

public Varnode(Address a,
               int sz,
               int symbolKey)

Parameters:

a - location varnode attached to

sz - size of varnode

symbolKey - associated symbol key

Method Detail

getSize

public int getSize()

Returns:

size of the varnode in bytes

getSpace

public int getSpace()

Returns:

the space this varnode belongs to (ram, register, ...)

getAddress

public Address getAddress()

Returns:

the address this varnode is attached to

getPCAddress

public Address getPCAddress()

Get the address where this varnode is defined or NO_ADDRESS if this varnode is an input

Returns:

the address

getOffset

public long getOffset()

Returns:

the offset into the address space varnode is defined within

getWordOffset

public long getWordOffset()

Returns the word offset into the address space this is defined within The word size is defined in the Language's .slaspec file with the "WORDSIZE" argument when DEFINEing a memory SPACE (capitalization is for emphasis; the directives are actually lowercase).

Returns:

the word offset into the address space this is defined within

isFree

public boolean isFree()

contains

public boolean contains(Address address)

Determine if this varnode contains the specified address

Parameters:

address - the address for which to check

Returns:

true if this varnode contains the specified address

intersects

public boolean intersects(Varnode varnode)

Determine if this varnode intersects another varnode.

Parameters:

varnode - other varnode

Returns:

true if this varnode intersects the specified varnode

intersects

public boolean intersects(AddressSetView set)

Determine if this varnode intersects the specified address set

Parameters:

set - address set

Returns:

true if this varnode intersects the specified address set

isAddress

public boolean isAddress()

Returns:

true if this varnode exists in a Memory space (vs. register etc...). Keep in mind this varnode may also correspond to a defined register if true is returned and isRegister() return false. Memory-based registers may be indirectly addressed which leads to the distinction with registers within the register space.

isRegister

public boolean isRegister()

Returns:

true if this varnode exists in a Register type space. If false is returned, keep in mind this varnode may still correspond to a defined register within a memory space. Memory-based registers may be indirectly addressed which leads to the distinction with registers within the register space.

isConstant

public boolean isConstant()

Returns:

true if this varnode is just a constant number

isUnique

public boolean isUnique()

Returns:

true if this varnode doesn't exist anywhere. A temporary variable.

isHash

public boolean isHash()

isInput

public boolean isInput()

Returns:

is input to a pcode op

isPersistant

public boolean isPersistant()

Returns:

is persistant

isAddrTied

public boolean isAddrTied()

Returns:

is mapped to an address

isUnaffected

public boolean isUnaffected()

getDef

public PcodeOp getDef()

Returns:

get the pcode op this varnode belongs to

getDescendants

public java.util.Iterator<PcodeOp> getDescendants()

Returns:

iterator to all PcodeOp s that take this as input

getLoneDescend

public PcodeOp getLoneDescend()

If there is only one PcodeOp taking this varnode as input, return it. Otherwise return null

Returns:

the lone descendant PcodeOp

getHigh

public HighVariable getHigh()

Returns:

the high level variable this varnode represents

getMergeGroup

public short getMergeGroup()

Returns:

the index of the group, within the high containing this, that are forced merged with this

buildXML

public void buildXML(java.lang.StringBuilder buf)

Parameters:

buf - is the builder to which to append XML

buildXMLAddress

public static void buildXMLAddress(java.lang.StringBuilder resBuf,
                                   Address addr,
                                   int size)

Build an XML document representation of a varnode with the given address and size.

Parameters:

resBuf - is the builder to which to append the XML

addr - location varnode is defined at

size - size of the varnode.

buildXMLAddress

public static java.lang.String buildXMLAddress(Address addr)

Convert an address into an XML document.

Parameters:

addr - -- Address to convert to XML

Returns:

XML string

buildXMLAddress

public static java.lang.String buildXMLAddress(Varnode[] varnodes,
                                               int logicalsize)

Convert a varnode array into an XML document.

Parameters:

varnodes - sequence of storage varnodes

logicalsize - the logical size value of the varnode

Returns:

XML string

appendSpaceOffset

public static void appendSpaceOffset(java.lang.StringBuilder buf,
                                     Address addr)

readXML

public static Varnode readXML(XmlPullParser parser,
                              PcodeFactory factory)
                       throws PcodeXMLException

Build a varnode from a SAX parse tree node

Parameters:

parser - the parser

factory - pcode factory used to create valid pcode

Returns:

new varnode element based on info in the XML.

Throws:

PcodeXMLException

trim

public void trim()

Trim a varnode in a constant space to the correct starting offset. Constant handles may contain constants of indeterminate size. This is where the size gets fixed, i.e. we mask off the constant to its proper size. A varnode that is ends up in pcode should call this method to ensure that varnodes always contains raw data. On the other hand, varnodes in handles are allowed to have offsets that violate size restrictions.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

toString

public java.lang.String toString(Language language)

Convert this varnode to an alternate String representation based on a specified language.

Parameters:

language -

Returns:

string representation

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

readXMLAddress

public static Address readXMLAddress(XmlElement el,
                                     AddressFactory addrFactory)

Create an address from a SAX parse tree node.

Parameters:

el - SAX parse tree element

addrFactory - address factory used to create valid addresses

Returns:

Address created from XML info

readXMLAddress

public static Address readXMLAddress(java.lang.String localName,
                                     org.xml.sax.Attributes attr,
                                     AddressFactory addrFactory)

readXMLAddress

public static Address readXMLAddress(java.lang.String addrstring,
                                     AddressFactory addrfactory,
                                     AddressSpace refSpace)
                              throws PcodeXMLException

Parse an XML containing an address. The format options are simple enough that we don't try to invoke an actual XML parser but just walk the string

Parameters:

addrstring - is the string containing the XML tag

addrfactory - is the factory that can produce addresses

refSpace - can be null but is otherwise the reference AddressSpace from which the request is sent.

Returns:

the created Address or Address.NO_ADDRESS in some special cases

Throws:

PcodeXMLException