A SLEIGH based implementation of the Emulate interface. More...

#include <emulate.hh>

Inheritance diagram for ghidra::EmulatePcodeCache:

Public Member Functions
	EmulatePcodeCache (Translate t, MemoryState s, BreakTable *b)
	Pcode cache emulator constructor. More...

bool	isInstructionStart (void) const
	Return true if we are at an instruction start. More...

int4	numCurrentOps (void) const
	Return number of pcode ops in translation of current instruction. More...

int4	getCurrentOpIndex (void) const
	Get the index of current pcode op within current instruction. More...

PcodeOpRaw *	getOpByIndex (int4 i) const
	Get pcode op in current instruction translation by index. More...

virtual void	setExecuteAddress (const Address &addr)
	Set current execution address. More...

virtual Address	getExecuteAddress (void) const
	Get current execution address. More...

void	executeInstruction (void)
	Execute (the rest of) a single machine instruction. More...

Public Member Functions inherited from ghidra::EmulateMemory
	EmulateMemory (MemoryState *mem)
	Construct given a memory state.

MemoryState *	getMemoryState (void) const
	Get the emulator's memory state. More...

Public Member Functions inherited from ghidra::Emulate
	Emulate (void)
	generic emulator constructor

void	setHalt (bool val)
	Set the halt state of the emulator. More...

bool	getHalt (void) const
	Get the halt state of the emulator. More...

void	executeCurrentOp (void)
	Do a single pcode op step. More...

Protected Member Functions
virtual void	fallthruOp (void)
	Execute fallthru semantics for the pcode cache. More...

virtual void	executeBranch (void)
	Execute branch (including relative branches) More...

virtual void	executeCallother (void)
	Execute breakpoint for this user-defined op. More...

Protected Member Functions inherited from ghidra::EmulateMemory
virtual void	executeUnary (void)
	Execute a unary arithmetic/logical operation.

virtual void	executeBinary (void)
	Execute a binary arithmetic/logical operation.

virtual void	executeLoad (void)
	Standard behavior for a p-code LOAD.

virtual void	executeStore (void)
	Standard behavior for a p-code STORE.

virtual bool	executeCbranch (void)
	Check if the conditional of a CBRANCH is true. More...

virtual void	executeBranchind (void)
	Standard behavior for a BRANCHIND.

virtual void	executeCall (void)
	Standard behavior for a p-code CALL.

virtual void	executeCallind (void)
	Standard behavior for a CALLIND.

virtual void	executeMultiequal (void)
	Standard behavior for a MULTIEQUAL (phi-node)

virtual void	executeIndirect (void)
	Standard behavior for an INDIRECT op.

virtual void	executeSegmentOp (void)
	Behavior for a SEGMENTOP.

virtual void	executeCpoolRef (void)
	Standard behavior for a CPOOLREF (constant pool reference) op.

virtual void	executeNew (void)
	Standard behavior for (low-level) NEW op.

Private Member Functions
void	clearCache (void)
	Clear the p-code cache. More...

void	createInstruction (const Address &addr)
	Cache pcode for instruction at given address. More...

void	establishOp (void)
	Set-up currentOp and currentBehave.

Private Attributes
Translate *	trans
	The SLEIGH translator.

vector< PcodeOpRaw * >	opcache
	The cache of current p-code ops.

vector< VarnodeData * >	varcache
	The cache of current varnodes.

vector< OpBehavior * >	inst
	Map from OpCode to OpBehavior.

BreakTable *	breaktable
	The table of breakpoints.

Address	current_address
	Address of current instruction being executed.

bool	instruction_start
	true if next pcode op is start of instruction

int4	current_op
	Index of current pcode op within machine instruction.

int4	instruction_length
	Length of current instruction in bytes.

Additional Inherited Members
Protected Attributes inherited from ghidra::EmulateMemory
MemoryState *	memstate
	The memory state of the emulator.

PcodeOpRaw *	currentOp
	Current op to execute.

Protected Attributes inherited from ghidra::Emulate
bool	emu_halted
	Set to true if the emulator is halted.

OpBehavior *	currentBehave
	Behavior of the next op to execute.

Detailed Description

A SLEIGH based implementation of the Emulate interface.

This implementation uses a Translate object to translate machine instructions into pcode and caches pcode ops for later use by the emulator. The pcode is cached as soon as the execution address is set, either explicitly, or via branches and fallthrus. There are additional methods for inspecting the pcode ops in the current instruction as a sequence.

Constructor & Destructor Documentation

◆ EmulatePcodeCache()

ghidra::EmulatePcodeCache::EmulatePcodeCache	(	Translate *	t,
		MemoryState *	s,
		BreakTable *	b
	)

Pcode cache emulator constructor.

Parameters

t	is the SLEIGH translator
s	is the MemoryState the emulator should manipulate
b	is the table of breakpoints the emulator should invoke

References breaktable, inst, ghidra::OpBehavior::registerInstructions(), ghidra::BreakTable::setEmulate(), and trans.

Member Function Documentation

◆ clearCache()

void ghidra::EmulatePcodeCache::clearCache ( void )

private

Clear the p-code cache.

Free all the VarnodeData and PcodeOpRaw objects and clear the cache.

References inst, opcache, and varcache.

Referenced by createInstruction().

◆ createInstruction()

void ghidra::EmulatePcodeCache::createInstruction ( const Address & addr )

private

Cache pcode for instruction at given address.

This is a private routine which does the work of translating a machine instruction into pcode, putting it into the cache, and setting up the iterators

Parameters

addr	is the address of the instruction to translate

References clearCache(), current_op, inst, instruction_length, instruction_start, ghidra::Translate::oneInstruction(), opcache, trans, and varcache.

Referenced by fallthruOp(), and setExecuteAddress().

◆ executeBranch()

void ghidra::EmulatePcodeCache::executeBranch ( void )

protectedvirtual

Execute branch (including relative branches)

Since the full instruction is cached, we can do relative branches properly.

Reimplemented from ghidra::EmulateMemory.

References current_op, ghidra::EmulateMemory::currentOp, fallthruOp(), ghidra::VarnodeData::getAddr(), ghidra::PcodeOpRaw::getInput(), ghidra::Address::getOffset(), opcache, and setExecuteAddress().

◆ executeCallother()

void ghidra::EmulatePcodeCache::executeCallother ( void )

protectedvirtual

Execute breakpoint for this user-defined op.

Look for a breakpoint for the given user-defined op and invoke it. If it doesn't exist, or doesn't replace the action, throw an exception

Reimplemented from ghidra::EmulateMemory.

References breaktable, ghidra::EmulateMemory::currentOp, ghidra::BreakTable::doPcodeOpBreak(), and fallthruOp().

◆ executeInstruction()

void ghidra::EmulatePcodeCache::executeInstruction ( void )

Execute (the rest of) a single machine instruction.

This routine executes an entire machine instruction at once, as a conventional debugger step function would do. If execution is at the start of an instruction, the breakpoints are checked and invoked as needed for the current address. If this routine is invoked while execution is in the middle of a machine instruction, execution is continued until the current instruction completes.

References breaktable, current_address, ghidra::BreakTable::doAddressBreak(), ghidra::Emulate::executeCurrentOp(), and instruction_start.

◆ fallthruOp()

void ghidra::EmulatePcodeCache::fallthruOp ( void )

protectedvirtual

Execute fallthru semantics for the pcode cache.

Update the iterator into the current pcode cache, and if necessary, generate the pcode for the fallthru instruction and reset the iterator.

Implements ghidra::Emulate.

References createInstruction(), current_address, current_op, establishOp(), instruction_length, instruction_start, and opcache.

Referenced by executeBranch(), and executeCallother().

◆ getCurrentOpIndex()

int4 ghidra::EmulatePcodeCache::getCurrentOpIndex ( void ) const

inline

Get the index of current pcode op within current instruction.

This routine can be used to determine where, within the sequence of ops in the translation of the entire machine instruction, the currently executing op is.

Returns: the index of the current (next) pcode op.

◆ getExecuteAddress()

Address ghidra::EmulatePcodeCache::getExecuteAddress ( void ) const

inlinevirtual

Get current execution address.

Returns: the currently executing machine address

Implements ghidra::Emulate.

◆ getOpByIndex()

PcodeOpRaw * ghidra::EmulatePcodeCache::getOpByIndex ( int4 i ) const

inline

Get pcode op in current instruction translation by index.

This routine can be used to examine ops other than the currently executing op in the machine instruction's translation sequence.

Parameters

i	is the desired op index

Returns: the pcode op at the indicated index

◆ isInstructionStart()

bool ghidra::EmulatePcodeCache::isInstructionStart ( void ) const

inline

Return true if we are at an instruction start.

Since the emulator can single step through individual pcode operations, the machine state may be halted in the middle of a single machine instruction, unlike conventional debuggers. This routine can be used to determine if execution is actually at the beginning of a machine instruction.

Returns: true if the next pcode operation is at the start of the instruction translation

◆ numCurrentOps()

int4 ghidra::EmulatePcodeCache::numCurrentOps ( void ) const

inline

Return number of pcode ops in translation of current instruction.

A typical machine instruction translates into a sequence of pcode ops.

Returns: the number of ops in the sequence

◆ setExecuteAddress()

void ghidra::EmulatePcodeCache::setExecuteAddress ( const Address & addr )

virtual

Set current execution address.

Set the current execution address and cache the pcode translation of the machine instruction at that address

Parameters

addr	is the address where execution should continue

Implements ghidra::Emulate.

References createInstruction(), current_address, and establishOp().

Referenced by executeBranch().

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

emulate.hh
emulate.cc

Public Member Functions

Protected Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ EmulatePcodeCache()

Member Function Documentation

◆ clearCache()

◆ createInstruction()

◆ executeBranch()

◆ executeCallother()

◆ executeInstruction()

◆ fallthruOp()

◆ getCurrentOpIndex()

◆ getExecuteAddress()

◆ getOpByIndex()

◆ isInstructionStart()

◆ numCurrentOps()

◆ setExecuteAddress()