Package ghidra.program.model.correlate

Class Block

java.lang.Object

ghidra.program.model.correlate.Block

public class Block
extends java.lang.Object

This class holds basic-block information for matching algorithms. It is used as a node to traverse the control-flow graph. It serves as a container for hashing information associated with Instructions in the block. It holds disambiguating hashes (calculated primarily from basic-block parent/child relationships) to help separate identical or near identical sequences of Instructions within one function.

Field Summary

Fields

Change	Modifier and Type	Field	Description
NEW	protected InstructHash[]	instList
NEW	protected boolean	isMatched
NEW	protected boolean	isVisited
NEW	protected CodeBlock	origBlock

Constructor Summary

Constructors

Change	Constructor	Description
Block(CodeBlock codeBlock)

Method Summary

Change	Modifier and Type	Method	Description
NEW	protected boolean	allUnknown(int startindex, int length)	If the indicated n-gram, within this block, consists of unmatched instructions
NEW	protected void	calcHashes(int minLength, int maxLength, boolean wholeBlock, boolean matchOnly, HashCalculator hashCalc)	Calculate n-gram hashes used for matching (for Instructions in this basic-block).
NEW	protected void	clearSort()	Clear out structures associated with main sort
	int	getMatchHash()
	int	hashGram(int gramSize, InstructHash instHash, HashCalculator hashCalc)	Calculate an n-gram hash, given a particular hash function
NEW	protected void	setMatched(int index)	Set up block match deconfliction value matchHash.

Methods inherited from class java.lang.Object

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

Field Detail

isMatched NEW

protected boolean isMatched

isVisited NEW

protected boolean isVisited

origBlock NEW

protected CodeBlock origBlock

instList NEW

protected InstructHash[] instList

Constructor Detail

Block

public Block(CodeBlock codeBlock)

Method Detail

clearSort NEW

protected void clearSort()

Clear out structures associated with main sort

setMatched NEW

protected void setMatched(int index)

Set up block match deconfliction value matchHash. This is fed into the n-gram hashes for Instructions contained by this block to uniquely associate the n-grams with this block (and the matching block on the other side)

Parameters:

index - is the 1-up index used to uniquely label this block

getMatchHash

public int getMatchHash()

Returns:

the main deconfliction hash feed

allUnknown NEW

protected boolean allUnknown(int startindex,
                             int length)

If the indicated n-gram, within this block, consists of unmatched instructions

Parameters:

startindex - is the index of the first Instruction in the n-gram

length - is the number of instructions in the n-gram

Returns:

true if all Instructions in the n-gram are not matched, false otherwise.

hashGram

public int hashGram(int gramSize,
                    InstructHash instHash,
                    HashCalculator hashCalc)
             throws MemoryAccessException

Calculate an n-gram hash, given a particular hash function

Parameters:

gramSize - is the size of the n-gram

instHash - is the first Instruction in the n-gram

hashCalc - is the hash function

Returns:

the final 32-bit hash

Throws:

MemoryAccessException

calcHashes NEW

protected void calcHashes(int minLength,
                          int maxLength,
                          boolean wholeBlock,
                          boolean matchOnly,
                          HashCalculator hashCalc)
                   throws MemoryAccessException

Calculate n-gram hashes used for matching (for Instructions in this basic-block). The exact hashes generated can be changed to get different looks at the data over multiple matching passes.

Parameters:

minLength - is the minimum length of an n-gram to calculate

maxLength - is the maximum length of an n-gram

wholeBlock - , true indicates a hash of the whole block should be calculated even if its size is below minLength

matchOnly - , true indicates hashes should only be calculated for previously matched, or small, blocks

hashCalc - is the hash function for this matching pass

Throws:

MemoryAccessException