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

Class Return

java.lang.Object

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

it.unive.lisa.program.cfg.statement.UnaryStatement

it.unive.lisa.program.cfg.statement.Return

All Implemented Interfaces:

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

public class Return
extends UnaryStatement
implements MetaVariableCreator

Returns an expression to the caller CFG, terminating the execution of the CFG where this statement lies. For terminating CFGs that do not return any value, use Ret.

Field Summary

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

offset

Constructor Summary

Constructors

Constructor	Description
Return(CFG cfg, CodeLocation location, Expression expression)	Builds the return, returning expression to the caller CFG, happening at the given location in the program.

Method Summary

Modifier and Type	Method	Description
Identifier	getMetaVariable()	Yields the meta variable that is introduced during the evaluation of the semantics of this object to store information about the value produced by this object.
<A extends AbstractState<A,H,V>,H extends HeapDomain<H>,V extends ValueDomain<V>> AnalysisState<A,H,V>	semantics(AnalysisState<A,H,V> entryState, InterproceduralAnalysis<A,H,V> interprocedural, StatementStore<A,H,V> expressions)	Computes the semantics of the statement, expressing how semantic information is transformed by the execution of this statement.
boolean	stopsExecution()	Whether or not this statement stops the execution of the containing cfg, either by throwing an error or returning a value.
java.lang.String	toString()

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

accept, equals, getExpression, hashCode, setOffset

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

compareTo, getCFG, getLocation, getOffset, throwsError

Methods inherited from class java.lang.Object

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

Constructor Detail

Return

public Return(CFG cfg,
              CodeLocation location,
              Expression expression)

Builds the return, returning expression to the caller CFG, happening at the given location in the program.

Parameters:

cfg - the cfg that this statement belongs to

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

expression - the expression to return

Method Detail

toString

public final java.lang.String toString()

Specified by:

toString in class Statement

stopsExecution

public boolean stopsExecution()

Description copied from class: Statement

Whether or not this statement stops the execution of the containing cfg, either by throwing an error or returning a value. To distinguish error-raising halting statements and normal ones, use Statement.throwsError().

Overrides:

stopsExecution in class Statement

Returns:

true only if that condition holds

getMetaVariable

public final Identifier getMetaVariable()

Description copied from interface: MetaVariableCreator

Yields the meta variable that is introduced during the evaluation of the semantics of this object to store information about the value produced by this object. Since the meta variable simulates a value pushed on the stack, it should be forgotten after it is consumed.

Specified by:

getMetaVariable in interface MetaVariableCreator

Returns:

the meta variable introduced by this object

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,
                                                                                                                                                            InterproceduralAnalysis<A,H,V> interprocedural,
                                                                                                                                                            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, InterproceduralAnalysis, 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

interprocedural - the interprocedural analysis 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