Package it.unive.lisa.program.cfg.statement

Class VariableRef

java.lang.Object

it.unive.lisa.program.cfg.statement.Statement

it.unive.lisa.program.cfg.statement.Expression

it.unive.lisa.program.cfg.statement.VariableRef

All Implemented Interfaces:

ProgramPoint, CodeElement, Node<Statement,Edge,CFG>, java.lang.Comparable<Statement>

public class VariableRef
extends Expression

A reference to a variable of the current CFG, identified by its name.

Field Summary

Fields inherited from class it.unive.lisa.program.cfg.statement.Statement

offset

Constructor Summary

Constructors

Constructor	Description
VariableRef(CFG cfg, CodeLocation location, java.lang.String name, Type type)	Builds the variable reference, identified by its name, happening at the given location in the program.
VariableRef(CFG cfg, java.lang.String name)	Builds the untyped variable reference, identified by its name.
VariableRef(CFG cfg, java.lang.String name, Type type)	Builds a typed variable reference, identified by its name and its type.

Method Summary

Modifier and Type	Method	Description
<V> boolean	accept(GraphVisitor<CFG,Statement,Edge,V> visitor, V tool)	Accepts the given GraphVisitor.
java.lang.String	getName()	Yields the name of this variable.
Variable	getVariable()	Yields a Variable representing the referenced variable.
int	hashCode()
boolean	isEqualTo(Statement st)	Checks if this node is effectively equal to the given one, that is, if they have the same structure while potentially being different instances.
<A extends AbstractState<A,H,V>,H extends HeapDomain<H>,V extends ValueDomain<V>> AnalysisState<A,H,V>	semantics(AnalysisState<A,H,V> entryState, CallGraph callGraph, StatementStore<A,H,V> expressions)	Computes the semantics of the statement, expressing how semantic information is transformed by the execution of this statement.
int	setOffset(int offset)	Sets the offset of this node to the given value, and then proceeds by setting the one of its nested nodes (if any) to subsequent values.
java.lang.String	toString()

Methods inherited from class it.unive.lisa.program.cfg.statement.Expression

getDynamicType, getMetaVariables, getParentStatement, getRootStatement, getRuntimeTypes, getStaticType, setParentStatement, setRuntimeTypes

Methods inherited from class it.unive.lisa.program.cfg.statement.Statement

compareTo, equals, getCFG, getLocation, getOffset, stopsExecution, throwsError

Methods inherited from class java.lang.Object

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

Constructor Detail

VariableRef

public VariableRef(CFG cfg,
                   java.lang.String name)

Builds the untyped variable reference, identified by its name. The location where this variable reference happens is unknown (i.e. no source file/line/column is available) and its type is Untyped.INSTANCE.

Parameters:

cfg - the cfg that this expression belongs to

name - the name of this variable

VariableRef

public VariableRef(CFG cfg,
                   java.lang.String name,
                   Type type)

Builds a typed variable reference, identified by its name and its type. The location where this variable reference happens is unknown (i.e. no source file/line/column is available).

Parameters:

cfg - the cfg that this expression belongs to

name - the name of this variable

type - the type of this variable

VariableRef

public VariableRef(CFG cfg,
                   CodeLocation location,
                   java.lang.String name,
                   Type type)

Builds the variable reference, identified by its name, happening at the given location in the program.

Parameters:

cfg - the cfg that this expression belongs to

location - the location where the expression is defined within the source file. If unknown, use null

name - the name of this variable

type - the type of this variable

Method Detail

setOffset

public int setOffset(int offset)

Description copied from interface: Node

Sets the offset of this node to the given value, and then proceeds by setting the one of its nested nodes (if any) to subsequent values. The last offset used is returned.

Parameters:

offset - the offset to set

Returns:

the last offset used while setting the offsets of nested nodes

getName

public java.lang.String getName()

Yields the name of this variable.

Returns:

the name of this variable

hashCode

public int hashCode()

Overrides:

hashCode in class Expression

isEqualTo

public boolean isEqualTo(Statement st)

Description copied from interface: Node

Checks if this node is effectively equal to the given one, that is, if they have the same structure while potentially being different instances.

Specified by:

isEqualTo in interface Node<Statement,Edge,CFG>

Overrides:

isEqualTo in class Expression

Parameters:

st - the other node

Returns:

true if this node and the given one are effectively equals

toString

public java.lang.String toString()

Specified by:

toString in class Statement

getVariable

public Variable getVariable()

Yields a Variable representing the referenced variable.

Returns:

the expression representing the variable

semantics

public <A extends AbstractState<A,H,V>,H extends HeapDomain<H>,V extends ValueDomain<V>> AnalysisState<A,H,V> semantics(AnalysisState<A,H,V> entryState,
                                                                                                                                                            CallGraph callGraph,
                                                                                                                                                            StatementStore<A,H,V> expressions)
                                                                                                                                                     throws SemanticException

Description copied from class: Statement

Computes the semantics of the statement, expressing how semantic information is transformed by the execution of this statement. This method is also responsible for recursively invoking the Statement.semantics(AnalysisState, CallGraph, StatementStore) of each nested Expression, saving the result of each call in expressions.

Specified by:

semantics in class Statement

Type Parameters:

A - the type of AbstractState

H - the type of the HeapDomain

V - the type of the ValueDomain

Parameters:

entryState - the entry state that represents the abstract values of each program variable and memory location when the execution reaches this statement

callGraph - the call graph of the program to analyze

expressions - the cache where analysis states of intermediate expressions must be stored

Returns:

the AnalysisState representing the abstract result of the execution of this statement

Throws:

SemanticException - if something goes wrong during the computation

accept

public <V> boolean accept(GraphVisitor<CFG,Statement,Edge,V> visitor,
                          V tool)

Description copied from interface: Node

Accepts the given GraphVisitor. Implementors of this method are responsible for invoking GraphVisitor.visit(Object, Graph, Node) on this node after Node.accept(GraphVisitor, Object) has been invoked on all nested nodes, if any. The visiting should stop at the first of such calls that return false.

Type Parameters:

V - the type of auxiliary tool that visitor can use

Parameters:

visitor - the visitor that is visiting the Graph containing this node

tool - the auxiliary tool that visitor can use

Returns:

whether or not the visiting should stop when this call returns, as decided by the visitor itself