Description

Semantic values for generating C source code ASTs.

Each SValue contains a string representation of a C expression.

Future work is planned to replace the string representation with a C source AST, in which case each SValue will have a pointer to a partly-constructed AST. In general, the parent pointers in these AST nodes are not initialized because many of these nodes are being shared across multiple subtrees. ROSE's instruction semantics framework relies very heavily on node sharing, but the AST was not designed for this. Do not expect AST traversals and analysis to work correctly for ASTs pointed to by an SValue. But never fear, the SValue's AST will be fixed by the time whole function ASTs are generated.

Definition at line 68 of file SourceAstSemantics.h.

#include <Rose/BinaryAnalysis/InstructionSemantics/SourceAstSemantics.h>

Inheritance diagram for Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue:

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Collaboration diagram for Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue:

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Public Types
using	Super = BaseSemantics::SValue
	Base type.

using	Ptr = SValuePtr
	Shared-ownership pointer.

Public Types inherited from Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue
using	Ptr = SValuePtr
	Shared-ownership pointer.

Public Member Functions
virtual BaseSemantics::SValuePtr	bottom_ (size_t nbits) const override
	Data-flow bottom value.

virtual BaseSemantics::SValuePtr	undefined_ (size_t nbits) const override
	Create a new undefined semantic value.

virtual BaseSemantics::SValuePtr	unspecified_ (size_t nbits) const override
	Create a new unspecified semantic value.

virtual BaseSemantics::SValuePtr	number_ (size_t nbits, uint64_t value) const override
	Create a new concrete semantic value.

virtual BaseSemantics::SValuePtr	boolean_ (bool value) const override
	Create a new, Boolean value.

virtual BaseSemantics::SValuePtr	copy (size_t new_width=0) const override
	Create a new value from an existing value, changing the width if `new_width` is non-zero.

virtual Sawyer::Optional< BaseSemantics::SValuePtr >	createOptionalMerge (const BaseSemantics::SValuePtr &, const BaseSemantics::MergerPtr &, const SmtSolverPtr &) const override
	Possibly create a new value by merging two existing values.

virtual bool	isBottom () const override
	Determines whether a value is a data-flow bottom.

virtual void	hash (Combinatorics::Hasher &) const override
	Hash this semantic value.

virtual void	print (std::ostream &, BaseSemantics::Formatter &) const override
	Print a value to a stream using default format.

virtual bool	may_equal (const BaseSemantics::SValuePtr &, const SmtSolverPtr &=SmtSolverPtr()) const override
	Virtual API.

virtual bool	must_equal (const BaseSemantics::SValuePtr &, const SmtSolverPtr &=SmtSolverPtr()) const override
	Virtual API.

virtual void	set_width (size_t) override
	Virtual API.

virtual bool	is_number () const override
	Virtual API.

virtual uint64_t	get_number () const override
	Virtual API.


virtual const std::string &	ctext () const
	C source text associated with this semantic value.

virtual void	ctext (const std::string &)
	C source text associated with this semantic value.

Public Member Functions inherited from Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue
SValuePtr	createMerged (const SValuePtr &other, const MergerPtr &, const SmtSolverPtr &) const
	Create a new value by merging two existing values.

size_t	nBits () const
	Property: value width.

bool	isConcrete () const
	Determines if the value is a concrete number.

Sawyer::Optional< uint64_t >	toUnsigned () const
	Converts a concrete value to a native unsigned integer.

Sawyer::Optional< int64_t >	toSigned () const
	Converts a concrete value to a native signed integer.

bool	mustEqual (const SValuePtr &other, const SmtSolverPtr &solver=SmtSolverPtr()) const
	Tests two values for equality.

bool	mayEqual (const SValuePtr &other, const SmtSolverPtr &solver=SmtSolverPtr()) const
	Tests two values for possible equality.

bool	isTrue () const
	Returns true if concrete non-zero.

bool	isFalse () const
	Returns true if concrete zero.

std::string	toString () const
	Render this symbolic expression as a string.

std::string	comment () const
	Property: Comment.

void	comment (const std::string &) const
	Property: Comment.

void	print (std::ostream &) const
	Print a value to a stream using default format.

WithFormatter	with_format (Formatter &)
	Used for printing values with formatting.

WithFormatter	operator+ (Formatter &)
	Used for printing values with formatting.

WithFormatter	operator+ (const std::string &linePrefix)
	Used for printing values with formatting.

virtual size_t	get_width () const
	Virtual API.

virtual std::string	get_comment () const
	Some subclasses support the ability to add comments to values.

virtual void	set_comment (const std::string &) const
	Some subclasses support the ability to add comments to values.

Public Member Functions inherited from Sawyer::SharedObject
	SharedObject ()
	Default constructor.

	SharedObject (const SharedObject &)
	Copy constructor.

virtual	~SharedObject ()
	Virtual destructor.

SharedObject &	operator= (const SharedObject &)
	Assignment.

Public Member Functions inherited from Sawyer::SharedFromThis< SValue >
SharedPointer< SValue >	sharedFromThis ()
	Create a shared pointer from `this`.

SharedPointer< const SValue >	sharedFromThis () const
	Create a shared pointer from `this`.

Static Public Member Functions
static SValuePtr	instance ()
	Instantiate a prototypical SValue.

static SValuePtr	instance_undefined (size_t nbits)
	Instantiate an undefined value.

static SValuePtr	instance_integer (size_t nbits, uint64_t value)
	Instantiate an integer constant.

static SValuePtr	promote (const BaseSemantics::SValuePtr &)
	Promote a base instance to an instance of this class.


static std::string	unsignedTypeNameForSize (size_t nbits)
	Name of integer type used for value.

static std::string	signedTypeNameForSize (size_t nbits)
	Name of integer type used for value.

Static Public Member Functions inherited from Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue
static SValuePtr	promote (const SValuePtr &)

Static Public Member Functions inherited from Sawyer::SmallObject
static SynchronizedPoolAllocator &	poolAllocator ()
	Return the pool allocator for this class.

static void *	operator new (size_t size)

static void	operator delete (void *ptr, size_t size)

Protected Member Functions
	SValue (size_t nbits)

	SValue (size_t nbits, uint64_t number)

	SValue (const SValue &other)

Protected Member Functions inherited from Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue
	SValue (size_t nbits)

	SValue (const SValue &other)

Protected Attributes
std::string	ctext_

Protected Attributes inherited from Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue
size_t	width

Static Protected Attributes
static size_t	nVariables_

Member Typedef Documentation

◆ Super

using Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::Super = BaseSemantics::SValue

Base type.

Definition at line 71 of file SourceAstSemantics.h.

◆ Ptr

using Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::Ptr = SValuePtr

Shared-ownership pointer.

Definition at line 74 of file SourceAstSemantics.h.

Member Function Documentation

◆ instance()

static SValuePtr Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::instance ( )

static

Instantiate a prototypical SValue.

This SValue will be used only for its virtual constructors and will never appear in an expression.

◆ instance_undefined()

static SValuePtr Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::instance_undefined ( size_t nbits )

static

Instantiate an undefined value.

Undefined values are distinct C variables that are never initialized.

◆ bottom_()

virtual BaseSemantics::SValuePtr Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::bottom_ ( size_t nBits ) const

overridevirtual

Data-flow bottom value.

Returns a new value that represents bottom in a data-flow analysis. If a semantic domain can represent a bottom value then the isBottom predicate is true when invoked on this method's return value. If a semantic domain cannot support a bottom value, then it may return some other value.

Implements Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue.

◆ undefined_()

virtual BaseSemantics::SValuePtr Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::undefined_ ( size_t nbits ) const

overridevirtual

Create a new undefined semantic value.

The new semantic value will have the same dynamic type as the value on which this virtual method is called. This is the most common way that a new value is created. The unspecified_ method is closely related.

See also: unspecified_

Implements Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue.

◆ unspecified_()

virtual BaseSemantics::SValuePtr Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::unspecified_ ( size_t nbits ) const

overridevirtual

Create a new unspecified semantic value.

The new semantic value will have the same dynamic type as the value on which this virtual method is called. Undefined (undefined_) and unspecified are closely related. Unspecified values are the same as undefined values except they're instantiated as the result of some machine instruction where the ISA documentation indicates that the value is unspecified (e.g., status flags for x86 shift and rotate instructions).

Most semantic domains make no distinction between undefined and unspecified.

See also: undefined_

Implements Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue.

◆ number_()

virtual BaseSemantics::SValuePtr Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::number_	(	size_t	nbits,
		uint64_t	number
	)		const

overridevirtual

Create a new concrete semantic value.

The new value will represent the specified concrete value and have the same dynamic type as the value on which this virtual method is called. This is the most common way that a new constant is created. The number is truncated to contain nbits bits (higher order bits are cleared).

Implements Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue.

◆ boolean_()

virtual BaseSemantics::SValuePtr Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::boolean_ ( bool value ) const

overridevirtual

Create a new, Boolean value.

The new semantic value will have the same dynamic type as the value on which this virtual method is called. This is how 1-bit flag register values (among others) are created. The base implementation uses number_() to construct a 1-bit value whose bit is zero (false) or one (true).

Reimplemented from Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue.

◆ copy()

virtual BaseSemantics::SValuePtr Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::copy ( size_t new_width = 0 ) const

overridevirtual

Create a new value from an existing value, changing the width if new_width is non-zero.

Increasing the width logically adds zero bits to the most significant side of the value; decreasing the width logically removes bits from the most significant side of the value.

Implements Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue.

◆ createOptionalMerge()

virtual Sawyer::Optional< BaseSemantics::SValuePtr > Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::createOptionalMerge	(	const BaseSemantics::SValuePtr &	other,
		const BaseSemantics::MergerPtr &	merger,
		const SmtSolverPtr &	solver
	)		const

overridevirtual

Possibly create a new value by merging two existing values.

This method optionally returns a new semantic value as the data-flow merge of this and other. If the two inputs are "equal" in some sense of the dataflow implementation then nothing is returned, otherwise a new value is returned. Typical usage is like this:

 if (SValuePtr merged = v1->createOptionalMerge(v2).orDefault()) {
     std::cout <<"v1 and v2 were merged to " <<*merged <<"\n";
 } else {
     std::cout <<"no merge is necessary\n";
 }
 
 or
 
@code
 SValuePtr merge;
 if (v1->createOptionalMerge(v2).assignTo(merged)) {
     std::cout <<"v1 and v2 were merged to " <<*merged <<"\n";
 } else {
     std::cout <<"v1 and v2 are equal in some sense (no merge necessary)\n";
 }

If you always want a copy regardless of whether the merge is necessary, then use the createMerged convenience function instead.

Implements Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue.

◆ isBottom()

virtual bool Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::isBottom ( ) const

overridevirtual

Determines whether a value is a data-flow bottom.

Returns true if this value represents a bottom value for data-flow analysis. Any RiscOperation performed on an operand whose isBottom predicate returns true will itself return a bottom value. This includes operations like "xor x x" which would normally return zero.

Implements Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue.

◆ hash()

virtual void Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::hash ( Combinatorics::Hasher & ) const

overridevirtual

Hash this semantic value.

Hashes the value by appending it to the specified hasher.

Implements Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue.

◆ print()

virtual void Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::print	(	std::ostream &	,
		BaseSemantics::Formatter &
	)		const

overridevirtual

Print a value to a stream using default format.

The value will normally occupy a single line and not contain leading space or line termination. See also, with_format().

Implements Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue.

◆ may_equal()

virtual bool Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::may_equal	(	const BaseSemantics::SValuePtr &	other,
		const SmtSolverPtr &	solver = `SmtSolverPtr()`
	)		const

overridevirtual

Virtual API.

See mayEqual.

Implements Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue.

◆ must_equal()

virtual bool Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::must_equal	(	const BaseSemantics::SValuePtr &	other,
		const SmtSolverPtr &	solver = `SmtSolverPtr()`
	)		const

overridevirtual

Virtual API.

See mustEqual.

Implements Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue.

◆ set_width()

virtual void Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::set_width ( size_t nbits )

overridevirtual

Virtual API.

See nBits.

Reimplemented from Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue.

◆ is_number()

virtual bool Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::is_number ( ) const

overridevirtual

Virtual API.

See isConcrete.

Implements Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue.

◆ get_number()

virtual uint64_t Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::get_number ( ) const

overridevirtual

Virtual API.

See toUnsigned and toSigned.

Implements Rose::BinaryAnalysis::InstructionSemantics::BaseSemantics::SValue.

Member Data Documentation

◆ nVariables_

size_t Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::nVariables_

staticprotected

Definition at line 77 of file SourceAstSemantics.h.

◆ ctext_

std::string Rose::BinaryAnalysis::InstructionSemantics::SourceAstSemantics::SValue::ctext_

protected

Definition at line 78 of file SourceAstSemantics.h.

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

SourceAstSemantics.h

Description

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Static Protected Attributes

Member Typedef Documentation

◆ Super

◆ Ptr

Member Function Documentation

◆ instance()

◆ instance_undefined()

◆ bottom_()

◆ undefined_()

◆ unspecified_()

◆ number_()

◆ boolean_()

◆ copy()

◆ createOptionalMerge()

◆ isBottom()

◆ hash()

◆ print()

◆ may_equal()

◆ must_equal()

◆ set_width()

◆ is_number()

◆ get_number()

Member Data Documentation

◆ nVariables_

◆ ctext_