Class FoldedState

java.lang.Object

ghidra.pcode.emu.jit.folding.FoldedState

All Implemented Interfaces:

PcodeExecutorState<MaskedBytes>, PcodeExecutorStatePiece<MaskedBytes, MaskedBytes>

public class FoldedState
extends Object
implements PcodeExecutorState<MaskedBytes>

A p-code executor state on MaskedBytes.

This is used as the state for interpretation when computing folded constants. Because the JIT only elides passage through registers and uniques, those are the only spaces we actually store here. Otherwise, this is roughly equivalent to BytesPcodeExecutorState, but we store both the values and masks of the MaskedBytes into the backing byte arrays.

Nested Class Summary

Nested classes/interfaces inherited from interface PcodeExecutorStatePiece

PcodeExecutorStatePiece.Reason

Constructor Summary

Constructors

Constructor	Description
FoldedState(Language language)	Construct a constant-folding state for the given language

Method Summary

Modifier and Type	Method	Description
void	clear()	Erase the entire state or piece
FoldedState	fork()	Fork this state, without callbacks, because they're not supported here.
FoldedState	fork(PcodeStateCallbacks cb)	Create a deep copy of this state
FoldedArithmetic	getArithmetic()	Get the arithmetic used to manipulate values of the type stored by this state
MemBuffer	getConcreteBuffer(Address address, PcodeArithmetic.Purpose purpose)	Bind a buffer of concrete bytes at the given start address
Language	getLanguage()	Get the language defining the address spaces of this state piece
Map<Register, MaskedBytes>	getRegisterValues()	Get all register values known to this state
MaskedBytes	getVar(AddressSpace space, MaskedBytes offset, int size, boolean quantize, PcodeExecutorStatePiece.Reason reason)	Get the value of a variable
MaskedBytes	getVarInternal(AddressSpace space, MaskedBytes offset, int size, PcodeExecutorStatePiece.Reason reason)	Get the value of a variable without issuing callbacks
boolean	intersectInPlace(FoldedState that)	Merge the given state into this one, modifying this state in place
void	setVar(AddressSpace space, MaskedBytes offset, int size, boolean quantize, MaskedBytes val)	Set the value of a variable
void	setVarInternal(AddressSpace space, MaskedBytes offset, int size, MaskedBytes val)	Set the value of a variable without issuing callbacks
Stream<PcodeExecutorStatePiece<?,?>>	streamPieces()	Stream over the pieces within.

Methods inherited from class Object

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

Methods inherited from interface PcodeExecutorState

getAddressArithmetic, paired

Methods inherited from interface PcodeExecutorStatePiece

checkRange, getNextEntryInternal, getNextEntryInternal, getVar, getVar, getVar, getVar, getVarInternal, inspectBigInteger, inspectByte, inspectConcrete, inspectInt, inspectLong, inspectRegisterValue, inspectShort, quantizeOffset, setBigInteger, setByte, setConcrete, setInt, setLong, setRegisterValue, setRegisterValue, setShort, setVar, setVar, setVar, setVar, setVarInternal

Constructor Details

FoldedState

public FoldedState(Language language)

Construct a constant-folding state for the given language

Parameters:

language - the language

Method Details

getLanguage

public Language getLanguage()

Description copied from interface: PcodeExecutorStatePiece

Get the language defining the address spaces of this state piece

Specified by:

getLanguage in interface PcodeExecutorStatePiece<MaskedBytes, MaskedBytes>

Returns:

the language

getArithmetic

public FoldedArithmetic getArithmetic()

Description copied from interface: PcodeExecutorStatePiece

Get the arithmetic used to manipulate values of the type stored by this state

Specified by:

getArithmetic in interface PcodeExecutorStatePiece<MaskedBytes, MaskedBytes>

Returns:

the arithmetic

streamPieces

public Stream<PcodeExecutorStatePiece<?,?>> streamPieces()

Description copied from interface: PcodeExecutorStatePiece

Stream over the pieces within.

If this piece is not a composition of others, then simply stream this piece in a singleton. Otherwise, stream the component pieces. (Do not include the composition itself, just the component pieces.)

Specified by:

streamPieces in interface PcodeExecutorStatePiece<MaskedBytes, MaskedBytes>

Returns:

the stream

setVar

public void setVar(AddressSpace space,
 MaskedBytes offset,
 int size,
 boolean quantize,
 MaskedBytes val)

Description copied from interface: PcodeExecutorStatePiece

Set the value of a variable

Specified by:

setVar in interface PcodeExecutorStatePiece<MaskedBytes, MaskedBytes>

Parameters:

space - the address space

offset - the offset within the space

size - the size of the variable

quantize - true to quantize to the language's "addressable unit"

val - the value

setVarInternal

public void setVarInternal(AddressSpace space,
 MaskedBytes offset,
 int size,
 MaskedBytes val)

Description copied from interface: PcodeExecutorStatePiece

Set the value of a variable without issuing callbacks

Specified by:

setVarInternal in interface PcodeExecutorStatePiece<MaskedBytes, MaskedBytes>

Parameters:

space - the address space

offset - the offset within the space

size - the size of the variable

val - the value

getVar

public MaskedBytes getVar(AddressSpace space,
 MaskedBytes offset,
 int size,
 boolean quantize,
 PcodeExecutorStatePiece.Reason reason)

Description copied from interface: PcodeExecutorStatePiece

Get the value of a variable

Specified by:

getVar in interface PcodeExecutorStatePiece<MaskedBytes, MaskedBytes>

Parameters:

space - the address space

offset - the offset within the space

size - the size of the variable

quantize - true to quantize to the language's "addressable unit"

reason - the reason for reading the variable

Returns:

the value

getVarInternal

public MaskedBytes getVarInternal(AddressSpace space,
 MaskedBytes offset,
 int size,
 PcodeExecutorStatePiece.Reason reason)

Description copied from interface: PcodeExecutorStatePiece

Get the value of a variable without issuing callbacks

Specified by:

getVarInternal in interface PcodeExecutorStatePiece<MaskedBytes, MaskedBytes>

Parameters:

space - the address space

offset - the offset within the space

size - the size of the variable

reason - the reason for reading the variable

Returns:

the value

getRegisterValues

public Map<Register, MaskedBytes> getRegisterValues()

Description copied from interface: PcodeExecutorStatePiece

Get all register values known to this state

When the state acts as a cache, it should only return those cached.

Specified by:

getRegisterValues in interface PcodeExecutorStatePiece<MaskedBytes, MaskedBytes>

Returns:

a map of registers and their values

getConcreteBuffer

public MemBuffer getConcreteBuffer(Address address,
 PcodeArithmetic.Purpose purpose)

Description copied from interface: PcodeExecutorStatePiece

Bind a buffer of concrete bytes at the given start address

Specified by:

getConcreteBuffer in interface PcodeExecutorStatePiece<MaskedBytes, MaskedBytes>

Parameters:

address - the start address

purpose - the reason why the emulator needs a concrete value

Returns:

a buffer

clear

public void clear()

Description copied from interface: PcodeExecutorStatePiece

Erase the entire state or piece

This is generally only useful when the state is itself a cache to another object. This will ensure the state is reading from that object rather than a stale cache. If this is not a cache, this could in fact clear the whole state, and the machine using it will be left in the dark.

Specified by:

clear in interface PcodeExecutorStatePiece<MaskedBytes, MaskedBytes>

fork

public FoldedState fork()

Fork this state, without callbacks, because they're not supported here.

Returns:

the copy

fork

public FoldedState fork(PcodeStateCallbacks cb)

Description copied from interface: PcodeExecutorStatePiece

Create a deep copy of this state

Specified by:

fork in interface PcodeExecutorState<MaskedBytes>

Specified by:

fork in interface PcodeExecutorStatePiece<MaskedBytes, MaskedBytes>

Parameters:

cb - callbacks to receive emulation events

Returns:

the copy

intersectInPlace

public boolean intersectInPlace(FoldedState that)

Merge the given state into this one, modifying this state in place

This is the merging operation used by FoldRevalidator. Where we have known values (1-bits in the mask) the other must also have known values, or else we erase our mask (and value) bits. If the other also has known values at the same offset, the values must match, or else we erase. These checks and erasures are applied with bit-level granularity. Any erasure results in a return of true (without short circuiting).

Parameters:

that - the other state

Returns:

true if this state changed as a result of this intersection