Package it.unive.lisa.symbolic.value

Class PushInv

java.lang.Object

it.unive.lisa.symbolic.SymbolicExpression

it.unive.lisa.symbolic.value.ValueExpression

it.unive.lisa.symbolic.value.PushInv

All Implemented Interfaces:

ScopedObject<SymbolicExpression>

public class PushInv
extends ValueExpression

An expression that pushes an invalid value on the stack. This is useful to represent bottom values.

Constructor Summary

Constructors

Constructor	Description
PushInv(Type staticType, CodeLocation location)	Builds the push invalid.

Method Summary

Modifier and Type	Method	Description
<T> T	accept(ExpressionVisitor<T> visitor, java.lang.Object... params)	Accepts an ExpressionVisitor, visiting this expression recursively.
boolean	equals(java.lang.Object obj)
int	hashCode()
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.
SymbolicExpression	popScope(ScopeToken token)	Pops the scope identified by the given token from the expression.
SymbolicExpression	pushScope(ScopeToken token)	Pushes a new scope, identified by the give token, in the expression.
java.lang.String	toString()

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

removeNegations

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

getCodeLocation, getStaticType

Methods inherited from class java.lang.Object

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

Constructor Detail

PushInv

public PushInv(Type staticType,
               CodeLocation location)

Builds the push invalid.

Parameters:

staticType - the static type of this expression

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

Method Detail

hashCode

public int hashCode()

Overrides:

hashCode in class SymbolicExpression

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class SymbolicExpression

toString

public java.lang.String toString()

Specified by:

toString in class SymbolicExpression

pushScope

public SymbolicExpression pushScope(ScopeToken token)

Description copied from class: SymbolicExpression

Pushes a new scope, identified by the give token, in the expression. This causes all Identifiers where Identifier.canBeScoped() holds to become OutOfScopeIdentifiers associated with the given token.

Specified by:

pushScope in interface ScopedObject<SymbolicExpression>

Specified by:

pushScope in class SymbolicExpression

Parameters:

token - the token identifying the scope to push

Returns:

a copy of this expression where the local variables have gone out of scope

popScope

public SymbolicExpression popScope(ScopeToken token)
                            throws SemanticException

Description copied from class: SymbolicExpression

Pops the scope identified by the given token from the expression. This causes all the invisible variables (i.e. OutOfScopeIdentifiers) mapped to the given scope to become visible (e.g. Variables) again. Note that invoking this method on Identifiers where Identifier.canBeScoped() holds will return null if (i) the identifier is not scoped, or (ii) the identifier is scoped by a different token.

Specified by:

popScope in interface ScopedObject<SymbolicExpression>

Specified by:

popScope in class SymbolicExpression

Parameters:

token - the token of the scope to be restored

Returns:

a copy of this expression where the local variables associated with the given scope are visible again

Throws:

SemanticException - if an error occurs during the computation

accept

public <T> T accept(ExpressionVisitor<T> visitor,
                    java.lang.Object... params)
             throws SemanticException

Description copied from class: SymbolicExpression

Accepts an ExpressionVisitor, visiting this expression recursively.

Specified by:

accept in class SymbolicExpression

Type Parameters:

T - the type of value produced by the visiting callbacks

Parameters:

visitor - the visitor

params - additional optional parameters to pass to each visiting callback

Returns:

the value produced by the visiting operation

Throws:

SemanticException - if an error occurs during the visiting

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