Package it.unive.lisa.symbolic.value

Class Identifier

java.lang.Object

it.unive.lisa.symbolic.SymbolicExpression

it.unive.lisa.symbolic.value.ValueExpression

it.unive.lisa.symbolic.value.Identifier

All Implemented Interfaces:

ScopedObject<SymbolicExpression>

Direct Known Subclasses:

HeapLocation, MemoryPointer, OutOfScopeIdentifier, Variable

public abstract class Identifier
extends ValueExpression

An identifier of a program variable, representing either a program variable (as an instance of Variable), or a resolved memory location (as an instance of HeapLocation).

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Identifier(Type staticType, java.lang.String name, boolean weak, Annotations annotations, CodeLocation location)	Builds the identifier.

Method Summary

Modifier and Type	Method	Description
void	addAnnotation(Annotation ann)	Adds an annotation to the annotations of this identifier.
abstract boolean	canBeScoped()	Yields true if a call to SymbolicExpression.pushScope(ScopeToken) on this identifier yields a new OutOfScopeIdentifier associated with the given scope, that can then be removed by SymbolicExpression.popScope(ScopeToken).
boolean	equals(java.lang.Object obj)
Annotations	getAnnotations()	Yields the annotations of this identifier.
java.lang.String	getName()	Yields the name of this identifier.
int	hashCode()
boolean	isScopedByCall()	Yields true if this is an OutOfScopeIdentifier whose (i) scope was introduced by a call, or (ii) inner identifier is an OutOfScopeIdentifier such that inner.isScopedByCall() holds.
boolean	isWeak()	Yields whether or not this identifier is weak.
Identifier	lub(Identifier other)	Yields the least upper bounds between two identifiers.
boolean	mightNeedRewriting()	Yields whether or not this expression can be considered safe to be processed by domains that only focus on ValueExpressions, or if it might need rewriting.

Methods inherited from class it.unive.lisa.symbolic.value.ValueExpression

removeNegations

Methods inherited from class it.unive.lisa.symbolic.SymbolicExpression

accept, getCodeLocation, getStaticType, popScope, pushScope, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Identifier

protected Identifier(Type staticType,
                     java.lang.String name,
                     boolean weak,
                     Annotations annotations,
                     CodeLocation location)

Builds the identifier.

Parameters:

staticType - the static type of this expression

name - the name of the identifier

weak - whether or not this identifier is weak, meaning that it should only receive weak assignments

annotations - the annotations of this identifier

location - the code location of the statement that has generated this identifier

Method Detail

getName

public java.lang.String getName()

Yields the name of this identifier.

Returns:

the name

isWeak

public boolean isWeak()

Yields whether or not this identifier is weak. Weak identifiers should only receive weak assignments, that is, the value of the identifier after the assignment should be the least upper bound between its old value and the fresh value being assigned. With strong identifiers instead, the new value corresponds to the freshly provided value.

Returns:

true if this identifier is weak, false otherwise

isScopedByCall

public boolean isScopedByCall()

Yields true if this is an OutOfScopeIdentifier whose (i) scope was introduced by a call, or (ii) inner identifier is an OutOfScopeIdentifier such that inner.isScopedByCall() holds.

Returns:

true if that condition holds

canBeScoped

public abstract boolean canBeScoped()

Yields true if a call to SymbolicExpression.pushScope(ScopeToken) on this identifier yields a new OutOfScopeIdentifier associated with the given scope, that can then be removed by SymbolicExpression.popScope(ScopeToken). If this method returns false, then SymbolicExpression.pushScope(ScopeToken) and SymbolicExpression.popScope(ScopeToken) will always return this identifier instead.

Returns:

true if that condition holds

hashCode

public int hashCode()

Overrides:

hashCode in class SymbolicExpression

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class SymbolicExpression

getAnnotations

public Annotations getAnnotations()

Yields the annotations of this identifier.

Returns:

the annotations of this identifier

addAnnotation

public void addAnnotation(Annotation ann)

Adds an annotation to the annotations of this identifier.

Parameters:

ann - the annotation to be added

lub

public Identifier lub(Identifier other)
               throws SemanticException

Yields the least upper bounds between two identifiers.

Parameters:

other - the other identifier

Returns:

the least upper bounds between two identifiers.

Throws:

SemanticException - if this and other are not equal.

mightNeedRewriting

public boolean mightNeedRewriting()

Description copied from class: SymbolicExpression

Yields whether or not this expression can be considered safe to be processed by domains that only focus on ValueExpressions, or if it might need rewriting. This is a definite answer: if this method returns true, than this expression is sure to not contain anything that deals with, or points to, the memory.

Specified by:

mightNeedRewriting in class SymbolicExpression

Returns:

whether or not this expression might need rewriting