Package ghidra.pcode.emu.jit

Class JitBytesPcodeExecutorStatePiece.JitBytesPcodeExecutorStateSpace

java.lang.Object

ghidra.pcode.exec.BytesPcodeExecutorStateSpace<Void>

ghidra.pcode.emu.jit.JitBytesPcodeExecutorStatePiece.JitBytesPcodeExecutorStateSpace

Enclosing class:

JitBytesPcodeExecutorStatePiece

public class JitBytesPcodeExecutorStatePiece.JitBytesPcodeExecutorStateSpace
extends BytesPcodeExecutorStateSpace<Void>

An object to manage state for a specific AddressSpace

Field Summary

Fields inherited from class ghidra.pcode.exec.BytesPcodeExecutorStateSpace

backing, bytes, EMPTY, language, space

Constructor Summary

Constructors

Constructor	Description
JitBytesPcodeExecutorStateSpace(Language language, AddressSpace space, Void backing)	Construct a state space

Method Summary

Modifier and Type	Method	Description
byte[]	getDirect(long offset)	Pre-fetch the byte array for the block (page) containing the given offset
byte[]	read(long offset, int size)	Read a variable from this (pre-fetched) state space

Methods inherited from class ghidra.pcode.exec.BytesPcodeExecutorStateSpace

addrRng, addrSet, clear, computeUninitialized, fork, getRegisterValues, getRegs, read, readBytes, readUninitializedFromBacking, spanRng, spanSet, warnAddressSet, warnUninit, write

Methods inherited from class java.lang.Object

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

Constructor Details

JitBytesPcodeExecutorStateSpace

public JitBytesPcodeExecutorStateSpace(Language language,
 AddressSpace space,
 Void backing)

Construct a state space

Parameters:

language - the emulation target language

space - the address space

backing - any extra read-through backing (not used)

Method Details

getDirect

public byte[] getDirect(long offset)

Pre-fetch the byte array for the block (page) containing the given offset

A translated passage is likely to call this several times in its constructor to pre-fetch the byte arrays for variables (ram, register, and unique) that it accesses directly, i.e., with a fixed offset. The generated code will then access the byte array directly to read and write the variable values in the emulator's state.

Parameters:

offset - the offset within this address space.

Returns:

the byte array for the containing block

read

public byte[] read(long offset,
 int size)

Read a variable from this (pre-fetched) state space

A translated passage is likely to call JitBytesPcodeExecutorStatePiece.getForSpace(AddressSpace, boolean) once or twice in its constructor to pre-fetch the per-space backing of any indirect memory variables that it accesses, i.e., variables with a dynamic offset. These are usually required for PcodeOp.LOAD and PcodeOp.STORE ops. The generated code will then invoke this method (and write) passing in the offset to access variables in the emulator's state at runtime.

Parameters:

offset - the offset (known at runtime)

size - the size of the variable

Returns:

the value of the variable as a byte array