Package ghidra.program.model.pcode

Class DynamicHash

java.lang.Object

ghidra.program.model.pcode.DynamicHash

public class DynamicHash
extends java.lang.Object

A hash utility to uniquely identify a temporary Varnode in data-flow Most Varnodes can be identified within the data-flow graph by their storage address and the address of the PcodeOp that defines them. For temporary registers, this does not work because the storage address is ephemeral. This class allows Varnodes like temporary registers (and constants) to be robustly identified by hashing details of the local data-flow. This class, when presented with a Varnode (via constructor), calculates a hash (getHash()) and an address (getAddress()) of the PcodeOp most closely associated with the Varnode, either the defining op or the op directly reading the Varnode. There are actually four hash variants that can be calculated, labeled 0, 1, 2, or 3, which incrementally hash in a larger portion of data-flow.

Field Summary

Fields

Modifier and Type	Field	Description
static int[]	transtable

Constructor Summary

Constructors

Constructor	Description
DynamicHash(PcodeOp op, int inputIndex)	Construct a level 0 hash on the input Varnode to the given PcodeOp The PcodeOp can be raw, no linked into a PcodeSyntaxTree
DynamicHash(Varnode root, int method)	Construct a hash of the given Varnode with a specific hash method.
DynamicHash(Varnode root, PcodeSyntaxTree fd)	Construct a unique hash for the given Varnode, which must be in a syntax tree.

Method Summary

Modifier and Type	Method	Description
static long[]	calcConstantHash(Instruction instr, long value)	Given a constant value accessed as an operand by a particular instruction, calculate a (level 0) hash for (any) corresponding constant varnode
static long	clearTotalPosition(long h)
static Varnode	findVarnode(PcodeSyntaxTree fd, Address addr, long h)
static void	gatherFirstLevelVars(java.util.ArrayList<Varnode> varlist, PcodeSyntaxTree fd, Address addr, long h)
Address	getAddress()
long	getHash()
static boolean	getIsNotAttached(long h)
static int	getMethodFromHash(long h)
static int	getOpCodeFromHash(long h)
static int	getPositionFromHash(long h)
static int	getSlotFromHash(long h)
static int	getTotalFromHash(long h)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

transtable

public static final int[] transtable

Constructor Detail

DynamicHash

public DynamicHash(Varnode root,
                   int method)

Construct a hash of the given Varnode with a specific hash method.

Parameters:

root - is the given Varnode

method - is the method (0, 1, 2, 3)

DynamicHash

public DynamicHash(Varnode root,
                   PcodeSyntaxTree fd)

Construct a unique hash for the given Varnode, which must be in a syntax tree. The hash method is cycled into a uniquely identifying one is found.

Parameters:

root - is the given Varnode

fd - is the PcodeSyntaxTree containing the Varnode

DynamicHash

public DynamicHash(PcodeOp op,
                   int inputIndex)

Construct a level 0 hash on the input Varnode to the given PcodeOp The PcodeOp can be raw, no linked into a PcodeSyntaxTree

Parameters:

op - is the given PcodeOp

inputIndex - is the index of the input Varnode to hash

Method Detail

getHash

public long getHash()

getAddress

public Address getAddress()

findVarnode

public static Varnode findVarnode(PcodeSyntaxTree fd,
                                  Address addr,
                                  long h)

gatherFirstLevelVars

public static void gatherFirstLevelVars(java.util.ArrayList<Varnode> varlist,
                                        PcodeSyntaxTree fd,
                                        Address addr,
                                        long h)

getSlotFromHash

public static int getSlotFromHash(long h)

getMethodFromHash

public static int getMethodFromHash(long h)

getOpCodeFromHash

public static int getOpCodeFromHash(long h)

getPositionFromHash

public static int getPositionFromHash(long h)

getTotalFromHash

public static int getTotalFromHash(long h)

getIsNotAttached

public static boolean getIsNotAttached(long h)

clearTotalPosition

public static long clearTotalPosition(long h)

calcConstantHash

public static long[] calcConstantHash(Instruction instr,
                                      long value)

Given a constant value accessed as an operand by a particular instruction, calculate a (level 0) hash for (any) corresponding constant varnode

Parameters:

instr - is the instruction referencing the constant

value - of the constant

Returns:

array of hash values (may be zero length)