Package ghidra.app.plugin.processors.sleigh

Class ParserWalker

java.lang.Object

ghidra.app.plugin.processors.sleigh.ParserWalker

public class ParserWalker
extends java.lang.Object

Class for walking the Sleigh Parser tree. The nodes of the tree are the Sleigh Constructors arranged for a particular instruction. This tree is walked for various purposes:

• SleighInstructionPrototype.resolve - initial parsing of instruction and building the tree
• SleighInstructionPrototype.resolveHandles - filling in Varnode values for all the Constructor exports
• PcodeEmit - for weaving together p-code for an instruction

Constructor Summary

Constructors

Constructor	Description
ParserWalker(SleighParserContext c)
ParserWalker(SleighParserContext c, SleighParserContext cross)	For use with pcode cross-build

Method Summary

Modifier and Type	Method	Description
void	allocateOperand()
void	baseState()	Initialize a walk of the tree
void	calcCurrentLength(int minLength, int numopers)	Calculate the length of the current constructor state assuming all its operands are constructed
Address	getAddr()
Constructor	getConstructor()
AddressSpace	getConstSpace()
int	getContextBits(int startbit, int size)
int	getContextBytes(int byteoff, int numbytes)
int	getCurrentLength()
java.lang.String	getCurrentSubtableName()
AddressSpace	getCurSpace()
FixedHandle	getFixedHandle(int i)
Address	getFlowDestAddr()
Address	getFlowRefAddr()
int	getInstructionBits(int startbit, int size)
int	getInstructionBytes(int byteoff, int numbytes)
Address	getNaddr()
int	getOffset(int i)	Get the offset into the instruction for the current node (i=-1) or one of the current node's children
int	getOperand()	Find the next child that needs to be traversed
FixedHandle	getParentHandle()
SleighParserContext	getParserContext()
ConstructState	getState()
boolean	isState()	Are we at the end of the tree walk
void	popOperand()	Move to the parent of the current node
void	pushOperand(int i)	Move down to a particular child of the current node.
void	setConstructor(Constructor ct)
void	setCurrentLength(int len)
void	setOffset(int off)
void	setOutOfBandState(Constructor ct, int index, ConstructState tempstate, ParserWalker otherwalker)
void	snippetState()	Create state suitable for parsing a just a p-code semantics snippet
void	subTreeState(ConstructState subtree)

Methods inherited from class java.lang.Object

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

Constructor Detail

ParserWalker

public ParserWalker(SleighParserContext c)

ParserWalker

public ParserWalker(SleighParserContext c,
                    SleighParserContext cross)

For use with pcode cross-build

Parameters:

c - context

cross - cross context

Method Detail

getParserContext

public SleighParserContext getParserContext()

baseState

public void baseState()

Initialize a walk of the tree

subTreeState

public void subTreeState(ConstructState subtree)

snippetState

public void snippetState()

Create state suitable for parsing a just a p-code semantics snippet

isState

public boolean isState()

Are we at the end of the tree walk

Returns:

true if there is more walk to go

getState

public ConstructState getState()

pushOperand

public void pushOperand(int i)

Move down to a particular child of the current node. Store what would be the next sibling to walk

Parameters:

i - is the index of the desired child

allocateOperand

public void allocateOperand()
                     throws UnknownInstructionException

Throws:

UnknownInstructionException

popOperand

public void popOperand()

Move to the parent of the current node

getOperand

public int getOperand()

Find the next child that needs to be traversed

Returns:

the index of the child

getFixedHandle

public FixedHandle getFixedHandle(int i)

getParentHandle

public FixedHandle getParentHandle()

getOffset

public int getOffset(int i)

Get the offset into the instruction for the current node (i=-1) or one of the current node's children

Parameters:

i - selects the desired child of the current node

Returns:

the offset (in bytes) for the selected node

setOffset

public void setOffset(int off)

getCurrentLength

public int getCurrentLength()

setCurrentLength

public void setCurrentLength(int len)

calcCurrentLength

public void calcCurrentLength(int minLength,
                              int numopers)

Calculate the length of the current constructor state assuming all its operands are constructed

getConstructor

public Constructor getConstructor()

Returns:

the Constructor for the current node in the walk

setConstructor

public void setConstructor(Constructor ct)

getAddr

public Address getAddr()

getNaddr

public Address getNaddr()

getCurSpace

public AddressSpace getCurSpace()

getConstSpace

public AddressSpace getConstSpace()

getFlowRefAddr

public Address getFlowRefAddr()

getFlowDestAddr

public Address getFlowDestAddr()

getInstructionBytes

public int getInstructionBytes(int byteoff,
                               int numbytes)
                        throws MemoryAccessException

Throws:

MemoryAccessException

getContextBytes

public int getContextBytes(int byteoff,
                           int numbytes)

getInstructionBits

public int getInstructionBits(int startbit,
                              int size)
                       throws MemoryAccessException

Throws:

MemoryAccessException

getContextBits

public int getContextBits(int startbit,
                          int size)

setOutOfBandState

public void setOutOfBandState(Constructor ct,
                              int index,
                              ConstructState tempstate,
                              ParserWalker otherwalker)

getCurrentSubtableName

public java.lang.String getCurrentSubtableName()