Description

Analysis that looks for no-op equivalents.

Definition at line 13 of file BinaryNoOperation.h.

#include <BinaryNoOperation.h>

Classes
class	StateNormalizer
	Base class for normalizing a state. More...

Public Types
typedef Sawyer::Container::Interval< size_t >	IndexInterval
	An interval of instruction indices. More...

typedef std::vector< IndexInterval >	IndexIntervals
	A vector of instruction indices. More...

Public Member Functions
	NoOperation ()
	Default constructor. More...

	NoOperation (const InstructionSemantics2::BaseSemantics::DispatcherPtr &cpu)
	Construct a new analysis with specified virtual CPU. More...

	NoOperation (BinaryAnalysis::Disassembler *)
	Construct a new analysis for a specific disassembler. More...

bool	isNoop (SgAsmInstruction *) const
	Determines if an instruction is a no-op. More...

bool	isNoop (const std::vector< SgAsmInstruction * > &) const
	Determines if a sequence of instructions is a no-op. More...

IndexIntervals	findNoopSubsequences (const std::vector< SgAsmInstruction * > &) const
	Finds all sequences of instructions that are equivalent to no-operation. More...


StateNormalizer::Ptr	stateNormalizer () const
	Property: state normalizer. More...

void	stateNormalizer (const StateNormalizer::Ptr &f)
	Property: state normalizer. More...


const Sawyer::Optional< rose_addr_t >	initialStackPointer () const
	Property: initial concrete value for stack pointer. More...

void	initialStackPointer (const Sawyer::Optional< rose_addr_t > &v)
	Property: initial concrete value for stack pointer. More...


bool	ignoreTerminalBranches () const
	Property: Whether terminal branches can be no-ops. More...

void	ignoreTerminalBranches (bool b)
	Property: Whether terminal branches can be no-ops. More...

Static Public Member Functions
static IndexIntervals	largestEarliestNonOverlapping (const IndexIntervals &)
	Select certain no-op sequences. More...

static std::vector< bool >	toVector (const IndexIntervals &, size_t size=0)
	Return a boolean vector. More...

static void	initDiagnostics ()
	Initializes and registers disassembler diagnostic streams. More...

Static Public Attributes
static Sawyer::Message::Facility	mlog
	Diagnostic streams. More...

Protected Member Functions
InstructionSemantics2::BaseSemantics::StatePtr	initialState (SgAsmInstruction *firstInsn) const

std::string	normalizeState (const InstructionSemantics2::BaseSemantics::StatePtr &) const

Member Typedef Documentation

typedef Sawyer::Container::Interval<size_t> Rose::BinaryAnalysis::NoOperation::IndexInterval

An interval of instruction indices.

Definition at line 16 of file BinaryNoOperation.h.

typedef std::vector<IndexInterval> Rose::BinaryAnalysis::NoOperation::IndexIntervals

A vector of instruction indices.

Definition at line 19 of file BinaryNoOperation.h.

Constructor & Destructor Documentation

Rose::BinaryAnalysis::NoOperation::NoOperation ( )

inline

Default constructor.

Since this default constructor has no information about the virtual CPU, it will assume that all instructions have an effect.

Definition at line 73 of file BinaryNoOperation.h.

Rose::BinaryAnalysis::NoOperation::NoOperation ( const InstructionSemantics2::BaseSemantics::DispatcherPtr & cpu )

inlineexplicit

Construct a new analysis with specified virtual CPU.

Definition at line 77 of file BinaryNoOperation.h.

Rose::BinaryAnalysis::NoOperation::NoOperation ( BinaryAnalysis::Disassembler * )

explicit

Construct a new analysis for a specific disassembler.

An analysis constructed this way will use the symbolic semantics domain.

Member Function Documentation

StateNormalizer::Ptr Rose::BinaryAnalysis::NoOperation::stateNormalizer ( ) const

inline

Property: state normalizer.

The state normalizer is responsible for normalizing a virtual machine state and turning it into a string. When looking for no-ops, if two state strings compare equal then the instruction(s) that transitioned the machine from one state to the other are effectively a no-op. In particular, the state normalizer should probably not try to compare instruction pointer registers, or memory that was read without being written (i.e., memory that sprang into existence by reading). The default normalizer does both of these things if the register state is derived from InstructionSemantics2::BaseSemantics::RegisterStateGeneric and the memory state is derived from InstructionSemantics2::BaseSemantics::MemoryCellList.

Definition at line 96 of file BinaryNoOperation.h.

void Rose::BinaryAnalysis::NoOperation::stateNormalizer ( const StateNormalizer::Ptr & f )

inline

Property: state normalizer.

The state normalizer is responsible for normalizing a virtual machine state and turning it into a string. When looking for no-ops, if two state strings compare equal then the instruction(s) that transitioned the machine from one state to the other are effectively a no-op. In particular, the state normalizer should probably not try to compare instruction pointer registers, or memory that was read without being written (i.e., memory that sprang into existence by reading). The default normalizer does both of these things if the register state is derived from InstructionSemantics2::BaseSemantics::RegisterStateGeneric and the memory state is derived from InstructionSemantics2::BaseSemantics::MemoryCellList.

Definition at line 97 of file BinaryNoOperation.h.

const Sawyer::Optional<rose_addr_t> Rose::BinaryAnalysis::NoOperation::initialStackPointer ( ) const

inline

Property: initial concrete value for stack pointer.

A concrete initial value for the stack pointer can be used to help decide whether memory addresses are recently popped. It may be possible to do this without a concrete value also, depending on the semantic domain.

Definition at line 106 of file BinaryNoOperation.h.

void Rose::BinaryAnalysis::NoOperation::initialStackPointer ( const Sawyer::Optional< rose_addr_t > & v )

inline

Property: initial concrete value for stack pointer.

A concrete initial value for the stack pointer can be used to help decide whether memory addresses are recently popped. It may be possible to do this without a concrete value also, depending on the semantic domain.

Definition at line 107 of file BinaryNoOperation.h.

bool Rose::BinaryAnalysis::NoOperation::ignoreTerminalBranches ( ) const

inline

Property: Whether terminal branches can be no-ops.

If set (the default) then branch instructions that appear as the last instruction of a basic block, and which have one constant, known successor which is not the fall-through address are not considered to be part of any no-op sequence.

Definition at line 116 of file BinaryNoOperation.h.

void Rose::BinaryAnalysis::NoOperation::ignoreTerminalBranches ( bool b )

inline

Property: Whether terminal branches can be no-ops.

If set (the default) then branch instructions that appear as the last instruction of a basic block, and which have one constant, known successor which is not the fall-through address are not considered to be part of any no-op sequence.

Definition at line 117 of file BinaryNoOperation.h.

bool Rose::BinaryAnalysis::NoOperation::isNoop ( SgAsmInstruction * ) const

Determines if an instruction is a no-op.

bool Rose::BinaryAnalysis::NoOperation::isNoop ( const std::vector< SgAsmInstruction * > & ) const

Determines if a sequence of instructions is a no-op.

IndexIntervals Rose::BinaryAnalysis::NoOperation::findNoopSubsequences ( const std::vector< SgAsmInstruction * > & ) const

Finds all sequences of instructions that are equivalent to no-operation.

static IndexIntervals Rose::BinaryAnalysis::NoOperation::largestEarliestNonOverlapping ( const IndexIntervals & )

static

Select certain no-op sequences.

Given a list of no-op sequences, such as returned by findNoopSubsequences, process the list so that the largest non-overlapping sequences are returned. If sequence A is larger than sequence B, then B is discarded. If A and B are the same size and overlap and A starts before B then B is discarded.

The return value is sorted by decreasing size and contains non-overlapping intervals.

static std::vector<bool> Rose::BinaryAnalysis::NoOperation::toVector	(	const IndexIntervals &	,
		size_t	size = `0`
	)

static

Return a boolean vector.

Returns a vector with one element per instruction. The element is true if the instruction is part of one of the specified index intervals. The returned vector will contain at least size elements.

static void Rose::BinaryAnalysis::NoOperation::initDiagnostics ( )

static

Initializes and registers disassembler diagnostic streams.

See Diagnostics::initialize().

Member Data Documentation

Sawyer::Message::Facility Rose::BinaryAnalysis::NoOperation::mlog

static

Diagnostic streams.

Definition at line 66 of file BinaryNoOperation.h.

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

BinaryNoOperation.h

Description

Classes

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Member Functions

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation