Context maintained while parsing a single instruction. More...

#include <context.hh>

Public Types
enum	parse_state { uninitialized = 0 , disassembly = 1 , pcode = 2 }
	Possible states of the ParserContext. More...

Public Member Functions
	ParserContext (ContextCache ccache, Translate trans)
	Constructor. More...

	~ParserContext (void)
	Destructor.

uint1 *	getBuffer (void)
	Get bytes in the stream at the point this instruction is encoded.

void	initialize (AddrSpace *spc, int4 maxstate=INITIAL_STATE_NUM)
	Preallocate nodes for constructor trees. More...

parse_state	getParserState (void) const
	Get the overall state of the parse.

void	setParserState (parse_state st)
	Update the overall parse state.

void	deallocateState (ParserWalkerChange &walker)
	Clear any existing constructor tree. More...

void	allocateOperand (int4 i, ParserWalkerChange &walker)
	Allocate a new child node in the constructor tree. More...

void	setAddr (const Address &ad)
	Set the starting address of the instruction.

void	setNaddr (const Address &ad)
	Set the ending address of the instruction.

void	setCalladdr (const Address &ad)
	Set the address of the call being overridden.

void	addCommit (TripleSymbol sym, int4 num, uintm mask, bool flow, ConstructState point)
	Add a formal SLEIGH context change command. More...

void	clearCommits (void)
	Clear all context commits.

void	applyCommits (void)
	Apply any pending commits to the context cache.

const Address &	getAddr (void) const
	Get the starting address of the current instruction.

const Address &	getNaddr (void) const
	Get the address of the next instruction.

const Address &	getN2addr (void) const
	Get the address of the instruction after the next.

const Address &	getDestAddr (void) const
	Get the destination address (inst_dest) for the overriden call.

const Address &	getRefAddr (void) const
	Get the reference address (inst_ref) for the p-code snippet.

AddrSpace *	getCurSpace (void) const
	Get the address space of the current instruction.

AddrSpace *	getConstSpace (void) const
	Get the address space for constants.

uintm	getInstructionBytes (int4 byteoff, int4 numbytes, uint4 off) const
	Get the specified instruction bytes. More...

uintm	getContextBytes (int4 byteoff, int4 numbytes) const
	Get bytes from the local context. More...

uintm	getInstructionBits (int4 startbit, int4 size, uint4 off) const
	Get the specific range of bits from the instruction stream. More...

uintm	getContextBits (int4 startbit, int4 size) const
	Get the specific range of bits from the local context. More...

void	setContextWord (int4 i, uintm val, uintm mask)
	Modify a context word, using given mask and value.

void	loadContext (void)
	Pull context words associated with the starting address into the local array.

int4	getLength (void) const
	Get the length of the current instruction.

void	setDelaySlot (int4 val)
	Set (the number of instruction bytes) in the delay slot.

int4	getDelaySlot (void) const
	Get the number of instruction bytes in the delay slot.

void	expandState (int4 amount)
	Expand the number of available nodes for the constructor tree. More...

Static Public Attributes
static constexpr int4	MAX_DEPTH = 32
	Maximum subconstructor depth in a single instruction.

static constexpr int4	MAX_OPERAND = 20
	Maximum operands for a single constructor.

static constexpr int4	MAX_INSTRUCTION_LEN = 16
	Maximum number of bytes in a single instruction.

static constexpr int4	INITIAL_STATE_NUM = 64
	Recommended number of initial states.

static constexpr int4	STATE_GROWTH = 64

Private Attributes
Translate *	translate
	The parent instruction parser.

parse_state	parsestate
	Overall state of the parse.

AddrSpace *	const_space
	Address space for constants.

uint1	buf [MAX_INSTRUCTION_LEN]
	Buffer of bytes in the instruction stream.

uintm *	context
	Pointer to local context.

int4	contextsize
	Number of entries in local context array.

ContextCache *	contcache
	Interface for getting/setting context.

vector< ContextSet >	contextcommit
	Changes to SLEIGH context slated by this instruction.

Address	addr
	Address of start of instruction.

Address	naddr
	Address of next instruction.

Address	n2addr
	Address of instruction after the next.

Address	calladdr
	For injections, this is the address of the call being overridden.

vector< ConstructState * >	state
	Available nodes for the constructor tree.

ConstructState *	base_state
	Root node of the constructor tree.

int4	alloc
	Number of unallocated ConstructState nodes remaining.

int4	delayslot
	delayslot depth

Friends
class	ParserWalker

class	ParserWalkerChange

Detailed Description

Context maintained while parsing a single instruction.

This contains:

the bytes encoding the instruction
the tree structure of the SLEIGH Constructors encountered while parsing the instruction
any formal named SLEIGH context values referenced by the instruction

Member Enumeration Documentation

◆ parse_state

enum ghidra::ParserContext::parse_state

Possible states of the ParserContext.

Enumerator
uninitialized	Instruction has not been parsed at all.
disassembly	Instruction is parsed in preparation for disassembly.
pcode	Instruction is parsed in preparation for generating p-code.

Constructor & Destructor Documentation

◆ ParserContext()

ghidra::ParserContext::ParserContext	(	ContextCache *	ccache,
		Translate *	trans
	)

Constructor.

Parameters

ccache	is the cache to use for formal context changes
trans	is the parent parser

References contcache, context, contextsize, ghidra::ContextDatabase::getContextSize(), ghidra::ContextCache::getDatabase(), parsestate, translate, and uninitialized.

Member Function Documentation

◆ addCommit()

void ghidra::ParserContext::addCommit	(	TripleSymbol *	sym,
		int4	num,
		uintm	mask,
		bool	flow,
		ConstructState *	point
	)

Add a formal SLEIGH context change command.

Parameters

sym	is a symbol that resolves to the address where the setting takes effect
num	is the index of the context word being affected
mask	indicates the bits within the context word that are affected
flow	is true if the context change flows forward from the point where it is set
point	is the parse point where the change was made

References context, contextcommit, ghidra::ContextSet::flow, ghidra::ContextSet::mask, ghidra::ContextSet::num, ghidra::ContextSet::point, ghidra::ContextSet::sym, and ghidra::ContextSet::value.

◆ allocateOperand()

void ghidra::ParserContext::allocateOperand	(	int4	i,
		ParserWalkerChange &	walker
	)

inline

Allocate a new child node in the constructor tree.

The next available node is linked to the current active node in the walker at the given operand index. The child node becomes the new active node for the walker. The underlying constructor is not yet assigned.

Parameters

i	is the operand index of the new child
walker	is the walker for the parse

References alloc, ghidra::ParserWalker::breadcrumb, ghidra::ConstructState::ct, ghidra::ParserWalker::depth, expandState(), MAX_DEPTH, MAX_OPERAND, ghidra::ConstructState::parent, ghidra::ParserWalker::point, ghidra::ConstructState::resolve, state, and STATE_GROWTH.

Referenced by ghidra::Sleigh::resolve(), and ghidra::InjectPayloadSleigh::setupParameters().

◆ deallocateState()

void ghidra::ParserContext::deallocateState ( ParserWalkerChange & walker )

inline

Clear any existing constructor tree.

The tree is reset to a single root node and the walker is prepared for a new parse

Parameters

walker is the walker to initialize for a traversal

References alloc, ghidra::ParserWalker::baseState(), ghidra::ParserWalkerChange::context, and state.

Referenced by ghidra::InjectPayloadSleigh::inject(), ghidra::ExecutablePcodeSleigh::inject(), and ghidra::Sleigh::resolve().

◆ expandState()

void ghidra::ParserContext::expandState ( int4 amount )

Expand the number of available nodes for the constructor tree.

This can be called in the middle of a parse to accommodate larger constructor trees.

Parameters

amount is the number of additional nodes to add

References alloc, MAX_OPERAND, and state.

Referenced by allocateOperand().

◆ getContextBits()

uintm ghidra::ParserContext::getContextBits	(	int4	startbit,
		int4	size
	)		const

Get the specific range of bits from the local context.

Parameters

startbit	is the offset of the first bit
size	is the number of bits to return

Returns: the requested range of bits (in the least significant positions and padded out with zero bits)

References context, and contextsize.

Referenced by ghidra::ParserWalker::getContextBits().

◆ getContextBytes()

uintm ghidra::ParserContext::getContextBytes	(	int4	bytestart,
		int4	size
	)		const

Get bytes from the local context.

Parameters

bytestart	is the offset of the first byte to grab
size	is the number of bytes to grab

Returns: the context bytes in a packed value

References context, and contextsize.

Referenced by ghidra::ParserWalker::getContextBytes().

◆ getInstructionBits()

uintm ghidra::ParserContext::getInstructionBits	(	int4	startbit,
		int4	size,
		uint4	off
	)		const

Get the specific range of bits from the instruction stream.

Get bits from the instruction stream assuming big endian encoding.

Parameters

startbit	is the offset of the first bit (within the instruction stream)
size	is the number of bits to grab
off	is the number of bytes in the instruction already read

Returns: the requested range of bits (in the least significant positions and padded out with zero bits)

References buf, and MAX_INSTRUCTION_LEN.

Referenced by ghidra::ParserWalker::getInstructionBits().

◆ getInstructionBytes()

uintm ghidra::ParserContext::getInstructionBytes	(	int4	bytestart,
		int4	size,
		uint4	off
	)		const

Get the specified instruction bytes.

Get bytes from the instruction stream into a packed value assuming a big endian encoding.

Parameters

bytestart	is the number of bytes to skip
size	is the number of bytes to pack
off	is the number of bytes in the instruction already read

Returns: the packed bytes from the instruction

References buf, and MAX_INSTRUCTION_LEN.

Referenced by ghidra::ParserWalker::getInstructionBytes().

◆ initialize()

void ghidra::ParserContext::initialize	(	AddrSpace *	spc,
		int4	maxstate = `INITIAL_STATE_NUM`
	)

Preallocate nodes for constructor trees.

Parameters

spc	is the address space used for constants
maxstate	is the number of nodes to allocate (initially)

References base_state, const_space, MAX_OPERAND, and state.

Referenced by ghidra::DisassemblyCache::initialize(), and ghidra::PcodeInjectLibrarySleigh::parseInject().

Member Data Documentation

◆ STATE_GROWTH

constexpr int4 ghidra::ParserContext::STATE_GROWTH = 64

staticconstexpr

Number of states to add for each expansion

Referenced by allocateOperand().

The documentation for this class was generated from the following files:

context.hh
context.cc

Public Types

Public Member Functions

Static Public Attributes

Private Attributes

Friends

Detailed Description

Member Enumeration Documentation

◆ parse_state

Constructor & Destructor Documentation

◆ ParserContext()

Member Function Documentation

◆ addCommit()

◆ allocateOperand()

◆ deallocateState()

◆ expandState()

◆ getContextBits()

◆ getContextBytes()

◆ getInstructionBits()

◆ getInstructionBytes()

◆ initialize()

Member Data Documentation

◆ STATE_GROWTH