Holds the state of the program (store and heap) at a given program point. More...

#include "clang/Analysis/FlowSensitive/DataflowEnvironment.h"

Classes
class	ValueModel
	Supplements `Environment` with non-standard comparison and join operations. More...

Public Member Functions
	Environment (DataflowAnalysisContext &DACtx)
	Creates an environment that uses `DACtx` to store objects that encompass the state of a program.

Environment &	operator= (const Environment &Other)=delete

	Environment (Environment &&Other)=default

Environment &	operator= (Environment &&Other)=default

	Environment (DataflowAnalysisContext &DACtx, const DeclContext &DeclCtx)
	Creates an environment that uses `DACtx` to store objects that encompass the state of a program.

Environment	fork () const
	Returns a new environment that is a copy of this one.

Environment	pushCall (const CallExpr *Call) const
	Creates and returns an environment to use for an inline analysis of the callee.

Environment	pushCall (const CXXConstructExpr *Call) const

void	popCall (const CallExpr *Call, const Environment &CalleeEnv)
	Moves gathered information back into `this` from a `CalleeEnv` created via `pushCall`.

void	popCall (const CXXConstructExpr *Call, const Environment &CalleeEnv)

bool	equivalentTo (const Environment &Other, Environment::ValueModel &Model) const
	Returns true if and only if the environment is equivalent to `Other`, i.e the two environments:

LatticeJoinEffect	widen (const Environment &PrevEnv, Environment::ValueModel &Model)
	Widens the environment point-wise, using `PrevEnv` as needed to inform the approximation.

StorageLocation &	createStorageLocation (QualType Type)
	Creates a storage location appropriate for `Type`.

StorageLocation &	createStorageLocation (const ValueDecl &D)
	Creates a storage location for `D`.

StorageLocation &	createStorageLocation (const Expr &E)
	Creates a storage location for `E`.

void	setStorageLocation (const ValueDecl &D, StorageLocation &Loc)
	Assigns `Loc` as the storage location of `D` in the environment.

StorageLocation *	getStorageLocation (const ValueDecl &D) const
	Returns the storage location assigned to `D` in the environment, or null if `D` isn't assigned a storage location in the environment.

void	removeDecl (const ValueDecl &D)
	Removes the location assigned to `D` in the environment (if any).

void	setStorageLocation (const Expr &E, StorageLocation &Loc)
	Assigns `Loc` as the storage location of the glvalue `E` in the environment.

StorageLocation *	getStorageLocation (const Expr &E) const
	Returns the storage location assigned to the glvalue `E` in the environment, or null if `E` isn't assigned a storage location in the environment.

RecordStorageLocation *	getThisPointeeStorageLocation () const
	Returns the storage location assigned to the `this` pointee in the environment or null if the `this` pointee has no assigned storage location in the environment.

RecordStorageLocation &	getResultObjectLocation (const Expr &RecordPRValue)
	Returns the location of the result object for a record-type prvalue.

Value *	getReturnValue () const
	Returns the return value of the current function.

StorageLocation *	getReturnStorageLocation () const
	Returns the storage location for the reference returned by the current function.

void	setReturnValue (Value *Val)
	Sets the return value of the current function.

void	setReturnStorageLocation (StorageLocation *Loc)
	Sets the storage location for the reference returned by the current function.

PointerValue &	getOrCreateNullPointerValue (QualType PointeeType)
	Returns a pointer value that represents a null pointer.

Value *	createValue (QualType Type)
	Creates a value appropriate for `Type`, if `Type` is supported, otherwise returns null.

StorageLocation &	createObject (QualType Ty, const Expr *InitExpr=nullptr)
	Creates an object (i.e.

StorageLocation &	createObject (const VarDecl &D)
	Creates an object for the variable declaration `D`.

StorageLocation &	createObject (const ValueDecl &D, const Expr *InitExpr)
	Creates an object for the variable declaration `D`.

void	setValue (const StorageLocation &Loc, Value &Val)
	Assigns `Val` as the value of `Loc` in the environment.

void	clearValue (const StorageLocation &Loc)
	Clears any association between `Loc` and a value in the environment.

void	setValue (const Expr &E, Value &Val)
	Assigns `Val` as the value of the prvalue `E` in the environment.

Value *	getValue (const StorageLocation &Loc) const
	Returns the value assigned to `Loc` in the environment or null if `Loc` isn't assigned a value in the environment.

Value *	getValue (const ValueDecl &D) const
	Equivalent to `getValue(getStorageLocation(D))` if `D` is assigned a storage location in the environment, otherwise returns null.

Value *	getValue (const Expr &E) const
	Equivalent to `getValue(getStorageLocation(E, SP))` if `E` is assigned a storage location in the environment, otherwise returns null.

template<typename T , typename... Args>
std::enable_if_t< std::is_base_of< Value, T >::value, T & >	create (Args &&...args)
	Creates a `T` (some subclass of `Value`), forwarding `args` to the constructor, and returns a reference to it.

IntegerValue &	getIntLiteralValue (llvm::APInt Value) const
	Returns a symbolic integer value that models an integer literal equal to `Value`

BoolValue &	getBoolLiteralValue (bool Value) const
	Returns a symbolic boolean value that models a boolean literal equal to `Value`

BoolValue &	makeAtomicBoolValue () const
	Returns an atomic boolean value.

BoolValue &	makeTopBoolValue () const
	Returns a unique instance of boolean Top.

BoolValue &	makeAnd (BoolValue &LHS, BoolValue &RHS) const
	Returns a boolean value that represents the conjunction of `LHS` and `RHS`.

BoolValue &	makeOr (BoolValue &LHS, BoolValue &RHS) const
	Returns a boolean value that represents the disjunction of `LHS` and `RHS`.

BoolValue &	makeNot (BoolValue &Val) const
	Returns a boolean value that represents the negation of `Val`.

BoolValue &	makeImplication (BoolValue &LHS, BoolValue &RHS) const
	Returns a boolean value represents `LHS` => `RHS`.

BoolValue &	makeIff (BoolValue &LHS, BoolValue &RHS) const
	Returns a boolean value represents `LHS` <=> `RHS`.

Atom	getFlowConditionToken () const
	Returns a boolean variable that identifies the flow condition (FC).

void	assume (const Formula &)
	Record a fact that must be true if this point in the program is reached.

bool	proves (const Formula &) const
	Returns true if the formula is always true when this point is reached.

bool	allows (const Formula &) const
	Returns true if the formula may be true when this point is reached.

const DeclContext *	getDeclCtx () const
	Returns the `DeclContext` of the block being analysed, if any.

const FunctionDecl *	getCurrentFunc () const
	Returns the function currently being analyzed, or null if the code being analyzed isn't part of a function.

bool	canDescend (unsigned MaxDepth, const DeclContext *Callee) const
	Returns whether this `Environment` can be extended to analyze the given `Callee` (i.e.

DataflowAnalysisContext &	getDataflowAnalysisContext () const
	Returns the `DataflowAnalysisContext` used by the environment.

Arena &	arena () const

LLVM_DUMP_METHOD void	dump () const

LLVM_DUMP_METHOD void	dump (raw_ostream &OS) const

Static Public Member Functions
static Environment	join (const Environment &EnvA, const Environment &EnvB, Environment::ValueModel &Model)
	Joins two environments by taking the intersection of storage locations and values that are stored in them.

Detailed Description

Holds the state of the program (store and heap) at a given program point.

WARNING: Symbolic values that are created by the environment for static local and global variables are not currently invalidated on function calls. This is unsound and should be taken into account when designing dataflow analyses.

Definition at line 54 of file DataflowEnvironment.h.

Constructor & Destructor Documentation

◆ Environment() [1/3]

clang::dataflow::Environment::Environment ( DataflowAnalysisContext & DACtx )

explicit

Creates an environment that uses DACtx to store objects that encompass the state of a program.

Definition at line 406 of file DataflowEnvironment.cpp.

◆ Environment() [2/3]

clang::dataflow::Environment::Environment ( Environment && Other )

default

◆ Environment() [3/3]

clang::dataflow::Environment::Environment	(	DataflowAnalysisContext &	DACtx,
		const DeclContext &	DeclCtx
	)

Creates an environment that uses DACtx to store objects that encompass the state of a program.

If DeclCtx is a function, initializes the environment with symbolic representations of the function parameters.

If DeclCtx is a non-static member function, initializes the environment with a symbolic representation of the this pointee.

Definition at line 416 of file DataflowEnvironment.cpp.

References createObject(), createValue(), clang::FunctionDecl::getBody(), clang::DeclContext::getNonClosureAncestor(), clang::FunctionDecl::parameters(), Parent, and setStorageLocation().

Member Function Documentation

◆ allows()

bool clang::dataflow::Environment::allows ( const Formula & F ) const

Returns true if the formula may be true when this point is reached.

Returns false if the formula is always false when this point is reached (or the flow condition is overly constraining) or if the solver times out.

Definition at line 937 of file DataflowEnvironment.cpp.

References clang::dataflow::DataflowAnalysisContext::flowConditionAllows().

◆ arena()

Arena & clang::dataflow::Environment::arena ( ) const

inline

Definition at line 581 of file DataflowEnvironment.h.

References clang::dataflow::DataflowAnalysisContext::arena().

Referenced by create(), getBoolLiteralValue(), getIntLiteralValue(), makeAnd(), makeAtomicBoolValue(), makeIff(), makeImplication(), makeNot(), makeOr(), makeTopBoolValue(), clang::dataflow::UncheckedOptionalAccessModel::merge(), and clang::dataflow::mergeDistinctValues().

◆ assume()

void clang::dataflow::Environment::assume ( const Formula & F )

Record a fact that must be true if this point in the program is reached.

Definition at line 929 of file DataflowEnvironment.cpp.

References clang::dataflow::DataflowAnalysisContext::addFlowConditionConstraint().

Referenced by clang::dataflow::UncheckedOptionalAccessModel::merge(), and clang::dataflow::mergeDistinctValues().

◆ canDescend()

bool clang::dataflow::Environment::canDescend	(	unsigned	MaxDepth,
		const DeclContext *	Callee
	)		const

Returns whether this Environment can be extended to analyze the given Callee (i.e.

if pushCall can be used), with recursion disallowed and a given MaxDepth.

Definition at line 459 of file DataflowEnvironment.cpp.

◆ clearValue()

void clang::dataflow::Environment::clearValue ( const StorageLocation & Loc )

inline

Clears any association between Loc and a value in the environment.

Definition at line 415 of file DataflowEnvironment.h.

◆ create()

template<typename T , typename... Args>

std::enable_if_t< std::is_base_of< Value, T >::value, T & > clang::dataflow::Environment::create ( Args &&... args )

inline

Creates a T (some subclass of Value), forwarding args to the constructor, and returns a reference to it.

The analysis context takes ownership of the created object. The object will be destroyed when the analysis context is destroyed.

Definition at line 460 of file DataflowEnvironment.h.

References arena(), and clang::dataflow::Arena::create().

Referenced by clang::dataflow::mergeDistinctValues(), and clang::dataflow::refreshRecordValue().

◆ createObject() [1/3]

StorageLocation & clang::dataflow::Environment::createObject	(	const ValueDecl &	D,
		const Expr *	InitExpr
	)

inline

Creates an object for the variable declaration D.

If InitExpr is non-null and has a value associated with it, initializes the object with this value. Otherwise, initializes the object with a value created using createValue(). Uses the storage location returned by DataflowAnalysisContext::getStableStorageLocation(D).

Definition at line 407 of file DataflowEnvironment.h.

References clang::ValueDecl::getType().

◆ createObject() [2/3]

StorageLocation & clang::dataflow::Environment::createObject ( const VarDecl & D )

inline

Creates an object for the variable declaration D.

If D has an initializer and this initializer is associated with a value, initializes the object with this value. Otherwise, initializes the object with a value created using createValue(). Uses the storage location returned by DataflowAnalysisContext::getStableStorageLocation(D).

Definition at line 398 of file DataflowEnvironment.h.

References clang::VarDecl::getInit(), and clang::ValueDecl::getType().

◆ createObject() [3/3]

StorageLocation & clang::dataflow::Environment::createObject	(	QualType	Ty,
		const Expr *	InitExpr = `nullptr`
	)

inline

Creates an object (i.e.

a storage location with an associated value) of type Ty. If InitExpr is non-null and has a value associated with it, initializes the object with this value. Otherwise, initializes the object with a value created using createValue().

Definition at line 389 of file DataflowEnvironment.h.

Referenced by Environment().

◆ createStorageLocation() [1/3]

StorageLocation & clang::dataflow::Environment::createStorageLocation ( const Expr & E )

Creates a storage location for E.

Does not assign the returned storage location to E in the environment. Does not assign a value to the returned storage location in the environment.

Definition at line 677 of file DataflowEnvironment.cpp.

References clang::dataflow::DataflowAnalysisContext::getStableStorageLocation().

◆ createStorageLocation() [2/3]

StorageLocation & clang::dataflow::Environment::createStorageLocation ( const ValueDecl & D )

Creates a storage location for D.

Does not assign the returned storage location to D in the environment. Does not assign a value to the returned storage location in the environment.

Definition at line 670 of file DataflowEnvironment.cpp.

References clang::dataflow::DataflowAnalysisContext::getStableStorageLocation().

◆ createStorageLocation() [3/3]

StorageLocation & clang::dataflow::Environment::createStorageLocation ( QualType Type )

Creates a storage location appropriate for Type.

Does not assign a value to the returned storage location in the environment.

Requirements:

Type must not be null.

Definition at line 666 of file DataflowEnvironment.cpp.

References clang::dataflow::DataflowAnalysisContext::createStorageLocation().

◆ createValue()

Value * clang::dataflow::Environment::createValue ( QualType Type )

Creates a value appropriate for Type, if Type is supported, otherwise returns null.

If Type is a pointer or reference type, creates all the necessary storage locations and values for indirections until it finds a non-pointer/non-reference type.

If Type is a class, struct, or union type, calls setValue() to associate the RecordValue with its storage location (RecordValue::getLoc()).

If Type is one of the following types, this function will always return a non-null pointer:

bool
Any integer type
Any class, struct, or union type

Requirements:

Type must not be null.

Definition at line 772 of file DataflowEnvironment.cpp.

References clang::dataflow::MaxCompositeValueSize, and Visited.

Referenced by Environment(), clang::dataflow::mergeDistinctValues(), and clang::dataflow::refreshRecordValue().

◆ dump() [1/2]

void clang::dataflow::Environment::dump ( ) const

Definition at line 965 of file DataflowEnvironment.cpp.

References dump().

Referenced by dump(), and clang::dataflow::runTypeErasedDataflowAnalysis().

◆ dump() [2/2]

void clang::dataflow::Environment::dump ( raw_ostream & OS ) const

Definition at line 941 of file DataflowEnvironment.cpp.

References clang::dataflow::DataflowAnalysisContext::dumpFlowCondition(), and V.

◆ equivalentTo()

bool clang::dataflow::Environment::equivalentTo	(	const Environment &	Other,
		Environment::ValueModel &	Model
	)		const

Returns true if and only if the environment is equivalent to Other, i.e the two environments:

have the same mappings from declarations to storage locations,
have the same mappings from expressions to storage locations,
have the same or equivalent (according to Model) values assigned to the same storage locations.

Requirements:

Other and this must use the same DataflowAnalysisContext.

Definition at line 548 of file DataflowEnvironment.cpp.

References clang::dataflow::compareKeyToValueMaps(), and clang::Other.

◆ fork()

Environment clang::dataflow::Environment::fork ( ) const

Returns a new environment that is a copy of this one.

The state of the program is initially the same, but can be mutated without affecting the original.

However the original should not be further mutated, as this may interfere with the fork. (In practice, values are stored independently, but the forked flow condition references the original).

Definition at line 410 of file DataflowEnvironment.cpp.

References clang::Copy, and clang::dataflow::DataflowAnalysisContext::forkFlowCondition().

Referenced by clang::dataflow::TypeErasedDataflowAnalysisState::fork(), and clang::dataflow::runTypeErasedDataflowAnalysis().

◆ getBoolLiteralValue()

BoolValue & clang::dataflow::Environment::getBoolLiteralValue ( bool Value ) const

inline

Returns a symbolic boolean value that models a boolean literal equal to Value

Definition at line 472 of file DataflowEnvironment.h.

References arena(), and clang::dataflow::Arena::makeBoolValue().

Referenced by clang::dataflow::evaluateBooleanEquality().

◆ getCurrentFunc()

const FunctionDecl * clang::dataflow::Environment::getCurrentFunc ( ) const

inline

Returns the function currently being analyzed, or null if the code being analyzed isn't part of a function.

Definition at line 569 of file DataflowEnvironment.h.

References getDeclCtx().

Referenced by getReturnStorageLocation(), getReturnValue(), setReturnStorageLocation(), and setReturnValue().

◆ getDataflowAnalysisContext()

DataflowAnalysisContext & clang::dataflow::Environment::getDataflowAnalysisContext ( ) const

inline

Returns the DataflowAnalysisContext used by the environment.

Definition at line 579 of file DataflowEnvironment.h.

Referenced by clang::dataflow::unpackValue().

◆ getDeclCtx()

const DeclContext * clang::dataflow::Environment::getDeclCtx ( ) const

inline

Returns the DeclContext of the block being analysed, if any.

Otherwise, returns null.

Definition at line 565 of file DataflowEnvironment.h.

Referenced by getCurrentFunc().

◆ getFlowConditionToken()

Atom clang::dataflow::Environment::getFlowConditionToken ( ) const

inline

Returns a boolean variable that identifies the flow condition (FC).

The flow condition is a set of facts that are necessarily true when the program reaches the current point, expressed as boolean formulas. The flow condition token is equivalent to the AND of these facts.

These may e.g. constrain the value of certain variables. A pointer variable may have a consistent modeled PointerValue throughout, but at a given point the Environment may tell us that the value must be non-null.

The FC is necessary but not sufficient for this point to be reachable. In particular, where the FC token appears in flow conditions of successor environments, it means "point X may have been reached", not "point X was reached".

Definition at line 542 of file DataflowEnvironment.h.

Referenced by clang::dataflow::mergeDistinctValues().

◆ getIntLiteralValue()

IntegerValue & clang::dataflow::Environment::getIntLiteralValue ( llvm::APInt Value ) const

inline

Returns a symbolic integer value that models an integer literal equal to Value

Definition at line 466 of file DataflowEnvironment.h.

References arena(), and clang::dataflow::Arena::makeIntLiteral().

◆ getOrCreateNullPointerValue()

PointerValue & clang::dataflow::Environment::getOrCreateNullPointerValue ( QualType PointeeType )

Returns a pointer value that represents a null pointer.

Calls with PointeeType that are canonically equivalent will return the same result.

Definition at line 734 of file DataflowEnvironment.cpp.

References clang::dataflow::DataflowAnalysisContext::getOrCreateNullPointerValue().

◆ getResultObjectLocation()

RecordStorageLocation & clang::dataflow::Environment::getResultObjectLocation ( const Expr & RecordPRValue )

Returns the location of the result object for a record-type prvalue.

In C++, prvalues of record type serve only a limited purpose: They can only be used to initialize a result object (e.g. a variable or a temporary). This function returns the location of that result object.

When creating a prvalue of record type, we already need the storage location of the result object to pass in this, even though prvalues are otherwise not associated with storage locations.

FIXME: Currently, this simply returns a stable storage location for E, but this doesn't do the right thing in scenarios like the following:

MyClass c = some_condition()? MyClass(foo) : MyClass(bar);

c

__device__ __2f16 float c

Definition: __clang_hip_libdevice_declares.h:304

Here, MyClass(foo) and MyClass(bar) will have two different storage locations, when in fact their storage locations should be the same. Eventually, we want to propagate storage locations from result objects down to the prvalues that initialize them, similar to the way that this is done in Clang's CodeGen.

Requirements: E must be a prvalue of record type.

Definition at line 722 of file DataflowEnvironment.cpp.

References clang::dataflow::DataflowAnalysisContext::getStableStorageLocation(), clang::Expr::getType(), clang::Expr::isPRValue(), and clang::Type::isRecordType().

◆ getReturnStorageLocation()

StorageLocation * clang::dataflow::Environment::getReturnStorageLocation ( ) const

inline

Returns the storage location for the reference returned by the current function.

This can be null if function doesn't return a single consistent reference.

Requirements: The current function must have a reference return type.

Definition at line 332 of file DataflowEnvironment.h.

References getCurrentFunc().

◆ getReturnValue()

Value * clang::dataflow::Environment::getReturnValue ( ) const

inline

Returns the return value of the current function.

This can be null if:

The function has a void return type
No return value could be determined for the function, for example because it calls a function without a body.

Requirements: The current function must have a non-reference return type.

Definition at line 320 of file DataflowEnvironment.h.

References getCurrentFunc().

◆ getStorageLocation() [1/2]

StorageLocation * clang::dataflow::Environment::getStorageLocation ( const Expr & E ) const

Returns the storage location assigned to the glvalue E in the environment, or null if E isn't assigned a storage location in the environment.

Requirements: E must be a glvalue or a BuiltinType::BuiltinFn

Definition at line 710 of file DataflowEnvironment.cpp.

References clang::Expr::getType(), clang::Expr::isGLValue(), and clang::Type::isSpecificBuiltinType().

◆ getStorageLocation() [2/2]

StorageLocation * clang::dataflow::Environment::getStorageLocation ( const ValueDecl & D ) const

Returns the storage location assigned to D in the environment, or null if D isn't assigned a storage location in the environment.

Definition at line 689 of file DataflowEnvironment.cpp.

Referenced by clang::dataflow::builtinTransferInitializer(), clang::dataflow::getBaseObjectLocation(), clang::dataflow::getImplicitObjectLocation(), getValue(), clang::dataflow::maybeUnpackLValueExpr(), clang::dataflow::propagateStorageLocation(), pushCall(), and clang::dataflow::refreshRecordValue().

◆ getThisPointeeStorageLocation()

RecordStorageLocation * clang::dataflow::Environment::getThisPointeeStorageLocation ( ) const

Returns the storage location assigned to the this pointee in the environment or null if the this pointee has no assigned storage location in the environment.

Definition at line 717 of file DataflowEnvironment.cpp.

Referenced by clang::dataflow::builtinTransferInitializer().

◆ getValue() [1/3]

Value * clang::dataflow::Environment::getValue ( const Expr & E ) const

Equivalent to getValue(getStorageLocation(E, SP)) if E is assigned a storage location in the environment, otherwise returns null.

Definition at line 760 of file DataflowEnvironment.cpp.

References getValue(), clang::dataflow::ignoreCFGOmittedNodes(), and clang::Expr::isPRValue().

◆ getValue() [2/3]

Value * clang::dataflow::Environment::getValue ( const StorageLocation & Loc ) const

Returns the value assigned to Loc in the environment or null if Loc isn't assigned a value in the environment.

Definition at line 749 of file DataflowEnvironment.cpp.

Referenced by clang::dataflow::builtinTransferInitializer(), clang::dataflow::evaluateBooleanEquality(), clang::dataflow::getBaseObjectLocation(), clang::dataflow::getImplicitObjectLocation(), getValue(), clang::dataflow::maybeUnpackLValueExpr(), popCall(), clang::dataflow::propagateValue(), clang::dataflow::recordsEqual(), and clang::dataflow::refreshRecordValue().

◆ getValue() [3/3]

Value * clang::dataflow::Environment::getValue ( const ValueDecl & D ) const

Equivalent to getValue(getStorageLocation(D)) if D is assigned a storage location in the environment, otherwise returns null.

Definition at line 753 of file DataflowEnvironment.cpp.

References getStorageLocation(), and getValue().

◆ join()

Environment clang::dataflow::Environment::join	(	const Environment &	EnvA,
		const Environment &	EnvB,
		Environment::ValueModel &	Model
	)

static

Joins two environments by taking the intersection of storage locations and values that are stored in them.

Distinct values that are assigned to the same storage locations in EnvA and EnvB are merged using Model.

Requirements:

EnvA and EnvB must use the same DataflowAnalysisContext.

Definition at line 610 of file DataflowEnvironment.cpp.

References clang::dataflow::areEquivalentValues(), clang::Func, clang::dataflow::intersectDeclToLoc(), clang::dataflow::DataflowAnalysisContext::joinFlowConditions(), clang::dataflow::joinLocToVal(), and clang::dataflow::mergeDistinctValues().

◆ makeAnd()

BoolValue & clang::dataflow::Environment::makeAnd	(	BoolValue &	LHS,
		BoolValue &	RHS
	)		const

inline

Returns a boolean value that represents the conjunction of LHS and RHS.

Subsequent calls with the same arguments, regardless of their order, will return the same result. If the given boolean values represent the same value, the result will be the value itself.

Definition at line 490 of file DataflowEnvironment.h.

References arena(), clang::dataflow::BoolValue::formula(), makeAnd(), and clang::dataflow::Arena::makeBoolValue().

Referenced by makeAnd().

◆ makeAtomicBoolValue()

BoolValue & clang::dataflow::Environment::makeAtomicBoolValue ( ) const

inline

Returns an atomic boolean value.

Definition at line 477 of file DataflowEnvironment.h.

References arena(), and clang::dataflow::Arena::makeAtomValue().

Referenced by clang::dataflow::evaluateBooleanEquality(), and clang::dataflow::UncheckedOptionalAccessModel::merge().

◆ makeIff()

BoolValue & clang::dataflow::Environment::makeIff	(	BoolValue &	LHS,
		BoolValue &	RHS
	)		const

inline

Returns a boolean value represents LHS <=> RHS.

Subsequent calls with the same arguments, regardless of their order, will return the same result. If the given boolean values represent the same value, the result will be a value that represents the true boolean literal.

Definition at line 523 of file DataflowEnvironment.h.

References arena(), clang::dataflow::BoolValue::formula(), and clang::dataflow::Arena::makeBoolValue().

Referenced by clang::dataflow::evaluateBooleanEquality().

◆ makeImplication()

BoolValue & clang::dataflow::Environment::makeImplication	(	BoolValue &	LHS,
		BoolValue &	RHS
	)		const

inline

Returns a boolean value represents LHS => RHS.

Subsequent calls with the same arguments, will return the same result. If the given boolean values represent the same value, the result will be a value that represents the true boolean literal.

Definition at line 514 of file DataflowEnvironment.h.

References arena(), clang::dataflow::BoolValue::formula(), and clang::dataflow::Arena::makeBoolValue().

◆ makeNot()

BoolValue & clang::dataflow::Environment::makeNot ( BoolValue & Val ) const

inline

Returns a boolean value that represents the negation of Val.

Subsequent calls with the same argument will return the same result.

Definition at line 506 of file DataflowEnvironment.h.

References arena(), clang::dataflow::BoolValue::formula(), clang::dataflow::Arena::makeBoolValue(), and makeNot().

Referenced by makeNot().

◆ makeOr()

BoolValue & clang::dataflow::Environment::makeOr	(	BoolValue &	LHS,
		BoolValue &	RHS
	)		const

inline

Returns a boolean value that represents the disjunction of LHS and RHS.

Subsequent calls with the same arguments, regardless of their order, will return the same result. If the given boolean values represent the same value, the result will be the value itself.

Definition at line 499 of file DataflowEnvironment.h.

References arena(), clang::dataflow::BoolValue::formula(), clang::dataflow::Arena::makeBoolValue(), and makeOr().

Referenced by makeOr().

◆ makeTopBoolValue()

BoolValue & clang::dataflow::Environment::makeTopBoolValue ( ) const

inline

Returns a unique instance of boolean Top.

Definition at line 482 of file DataflowEnvironment.h.

References arena(), and clang::dataflow::Arena::makeTopValue().

Referenced by clang::dataflow::UncheckedOptionalAccessModel::widen(), and clang::dataflow::widenDistinctValues().

◆ operator=() [1/2]

Environment & clang::dataflow::Environment::operator= ( const Environment & Other )

delete

◆ operator=() [2/2]

Environment & clang::dataflow::Environment::operator= ( Environment && Other )

default

◆ popCall() [1/2]

void clang::dataflow::Environment::popCall	(	const CallExpr *	Call,
		const Environment &	CalleeEnv
	)

Moves gathered information back into this from a CalleeEnv created via pushCall.

Definition at line 517 of file DataflowEnvironment.cpp.

References clang::Call, setStorageLocation(), and setValue().

◆ popCall() [2/2]

void clang::dataflow::Environment::popCall	(	const CXXConstructExpr *	Call,
		const Environment &	CalleeEnv
	)

Definition at line 537 of file DataflowEnvironment.cpp.

References clang::Call, getValue(), and setValue().

◆ proves()

bool clang::dataflow::Environment::proves ( const Formula & F ) const

Returns true if the formula is always true when this point is reached.

Returns false if the formula may be false (or the flow condition isn't sufficiently precise to prove that it is true) or if the solver times out.

Note that there is an asymmetry between this function and allows() in that they both return false if the solver times out. The assumption is that if proves() or allows() returns true, this will result in a diagnostic, and we want to bias towards false negatives in the case where the solver times out.

Definition at line 933 of file DataflowEnvironment.cpp.

References clang::dataflow::DataflowAnalysisContext::flowConditionImplies().

◆ pushCall() [1/2]

Environment clang::dataflow::Environment::pushCall ( const CallExpr * Call ) const

Creates and returns an environment to use for an inline analysis of the callee.

Uses the storage location from each argument in the Call as the storage location for the corresponding parameter in the callee.

Requirements:

The callee of Call must be a FunctionDecl.

The body of the callee must not reference globals.

The arguments of Call must map 1:1 to the callee's parameters.

Definition at line 464 of file DataflowEnvironment.cpp.

References clang::Call, Env, and getStorageLocation().

◆ pushCall() [2/2]

Environment clang::dataflow::Environment::pushCall ( const CXXConstructExpr * Call ) const

Definition at line 483 of file DataflowEnvironment.cpp.

References clang::Call, and Env.

◆ removeDecl()

void clang::dataflow::Environment::removeDecl ( const ValueDecl & D )

Removes the location assigned to D in the environment (if any).

Definition at line 699 of file DataflowEnvironment.cpp.

◆ setReturnStorageLocation()

void clang::dataflow::Environment::setReturnStorageLocation ( StorageLocation * Loc )

inline

Sets the storage location for the reference returned by the current function.

Requirements: The current function must have a reference return type.

Definition at line 353 of file DataflowEnvironment.h.

References getCurrentFunc().

◆ setReturnValue()

void clang::dataflow::Environment::setReturnValue ( Value * Val )

inline

Sets the return value of the current function.

Requirements: The current function must have a non-reference return type.

Definition at line 342 of file DataflowEnvironment.h.

References getCurrentFunc().

◆ setStorageLocation() [1/2]

void clang::dataflow::Environment::setStorageLocation	(	const Expr &	E,
		StorageLocation &	Loc
	)

Assigns Loc as the storage location of the glvalue E in the environment.

Requirements:

E must not be assigned a storage location in the environment. E must be a glvalue or a BuiltinType::BuiltinFn

Definition at line 701 of file DataflowEnvironment.cpp.

References clang::Expr::getType(), clang::Expr::isGLValue(), and clang::Type::isSpecificBuiltinType().

◆ setStorageLocation() [2/2]

void clang::dataflow::Environment::setStorageLocation	(	const ValueDecl &	D,
		StorageLocation &	Loc
	)

Assigns Loc as the storage location of D in the environment.

Requirements:

D must not already have a storage location in the environment.

Definition at line 684 of file DataflowEnvironment.cpp.

Referenced by Environment(), popCall(), clang::dataflow::propagateStorageLocation(), and clang::dataflow::refreshRecordValue().

◆ setValue() [1/2]

void clang::dataflow::Environment::setValue	(	const Expr &	E,
		Value &	Val
	)

Assigns Val as the value of the prvalue E in the environment.

If E is not yet associated with a storage location, associates it with a newly created storage location. In any case, associates the storage location of E with Val.

Once the migration to strict handling of value categories is complete (see https://discourse.llvm.org/t/70086), this function will be renamed to setValue(). At this point, prvalue expressions will be associated directly with Values, and the legacy behavior of associating prvalue expressions with storage locations (as described above) will be eliminated.

Requirements:

E must be a prvalue If Val is a RecordValue, its RecordStorageLocation must be the same as that of any RecordValue that has already been associated with E. This is to guarantee that the result object initialized by a prvalue RecordValue has a durable storage location.

Definition at line 744 of file DataflowEnvironment.cpp.

References clang::Expr::isPRValue().

◆ setValue() [2/2]

void clang::dataflow::Environment::setValue	(	const StorageLocation &	Loc,
		Value &	Val
	)

Assigns Val as the value of Loc in the environment.

Definition at line 738 of file DataflowEnvironment.cpp.

Referenced by clang::dataflow::builtinTransferInitializer(), clang::dataflow::maybeUnpackLValueExpr(), popCall(), clang::dataflow::propagateValue(), and clang::dataflow::refreshRecordValue().

◆ widen()

LatticeJoinEffect clang::dataflow::Environment::widen	(	const Environment &	PrevEnv,
		Environment::ValueModel &	Model
	)

Widens the environment point-wise, using PrevEnv as needed to inform the approximation.

Requirements:

PrevEnv must be the immediate previous version of the environment. PrevEnv and this must use the same DataflowAnalysisContext.

Definition at line 576 of file DataflowEnvironment.cpp.

References clang::dataflow::Changed, clang::dataflow::Unchanged, and clang::dataflow::widenKeyToValueMap().

Referenced by clang::dataflow::runTypeErasedDataflowAnalysis().

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

include/clang/Analysis/FlowSensitive/DataflowEnvironment.h
lib/Analysis/FlowSensitive/DataflowEnvironment.cpp

Classes

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ Environment() [1/3]

◆ Environment() [2/3]

◆ Environment() [3/3]

Member Function Documentation

◆ allows()

◆ arena()

◆ assume()

◆ canDescend()

◆ clearValue()

◆ create()

◆ createObject() [1/3]

◆ createObject() [2/3]

◆ createObject() [3/3]

◆ createStorageLocation() [1/3]

◆ createStorageLocation() [2/3]

◆ createStorageLocation() [3/3]

◆ createValue()

◆ dump() [1/2]

◆ dump() [2/2]

◆ equivalentTo()

◆ fork()

◆ getBoolLiteralValue()

◆ getCurrentFunc()

◆ getDataflowAnalysisContext()

◆ getDeclCtx()

◆ getFlowConditionToken()

◆ getIntLiteralValue()

◆ getOrCreateNullPointerValue()

◆ getResultObjectLocation()

◆ getReturnStorageLocation()

◆ getReturnValue()

◆ getStorageLocation() [1/2]

◆ getStorageLocation() [2/2]

◆ getThisPointeeStorageLocation()

◆ getValue() [1/3]

◆ getValue() [2/3]

◆ getValue() [3/3]

◆ join()

◆ makeAnd()

◆ makeAtomicBoolValue()

◆ makeIff()

◆ makeImplication()

◆ makeNot()

◆ makeOr()

◆ makeTopBoolValue()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ popCall() [1/2]

◆ popCall() [2/2]

◆ proves()

◆ pushCall() [1/2]

◆ pushCall() [2/2]

◆ removeDecl()

◆ setReturnStorageLocation()

◆ setReturnValue()

◆ setStorageLocation() [1/2]

◆ setStorageLocation() [2/2]

◆ setValue() [1/2]

◆ setValue() [2/2]

◆ widen()