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

Class Statement

java.lang.Object

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

All Implemented Interfaces:

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

Direct Known Subclasses:

Expression, NoOp, Ret, UnaryStatement

public abstract class Statement
extends java.lang.Object
implements CodeNode<CFG,Statement,Edge>, ProgramPoint, java.lang.Comparable<Statement>

A statement of the program to analyze.

Field Summary

Fields

Modifier and Type	Field	Description
protected int	offset	The offset of the statement within the cfg.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Statement(CFG cfg, CodeLocation location)	Builds a statement happening at the given source location.

Method Summary

Modifier and Type	Method	Description
int	compareTo(Statement o)
boolean	equals(java.lang.Object obj)
CFG	getCFG()	Yields the CFG that this program point belongs to.
Statement	getEvaluationPredecessor()	Yields the Statement that is evaluated right before this one, such that querying for the entry state of this expression is equivalent to querying the exit state of the returned one.
CodeLocation	getLocation()	Yields the location where this code element appears in the program.
int	getOffset()	Yields the offset of this node relative to its containing graph.
Statement	getStatementEvaluatedBefore(Statement other)	Yields the Statement that precedes the given one, assuming that other is contained into this expression.
int	hashCode()
abstract <A extends AbstractState<A,H,V,T>,H extends HeapDomain<H>,V extends ValueDomain<V>,T extends TypeDomain<T>> AnalysisState<A,H,V,T>	semantics(AnalysisState<A,H,V,T> entryState, InterproceduralAnalysis<A,H,V,T> interprocedural, StatementStore<A,H,V,T> 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.
boolean	throwsError()	Whether or not this statement throws an error, halting the normal execution of the containing cfg.
abstract java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface it.unive.lisa.util.datastructures.graph.code.CodeNode

setOffset

Methods inherited from interface it.unive.lisa.util.datastructures.graph.Node

accept

Methods inherited from interface it.unive.lisa.program.cfg.ProgramPoint

getProgram

Field Detail

offset

protected int offset

The offset of the statement within the cfg.

Constructor Detail

Statement

protected Statement(CFG cfg,
                    CodeLocation location)

Builds a statement happening at the given source location.

Parameters:

cfg - the cfg that this statement belongs to

location - the location where this statement is defined within the program

Method Detail

getCFG

public final CFG getCFG()

Description copied from interface: ProgramPoint

Yields the CFG that this program point belongs to.

Specified by:

getCFG in interface ProgramPoint

Returns:

the containing cfg

getOffset

public final int getOffset()

Description copied from interface: CodeNode

Yields the offset of this node relative to its containing graph.

Specified by:

getOffset in interface CodeNode<CFG,Statement,Edge>

Returns:

the offset

stopsExecution

public boolean stopsExecution()

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 throwsError().

Returns:

true only if that condition holds

throwsError

public boolean throwsError()

Whether or not this statement throws an error, halting the normal execution of the containing cfg.

Returns:

true only if that condition holds

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

toString

public abstract java.lang.String toString()

Overrides:

toString in class java.lang.Object

semantics

public abstract <A extends AbstractState<A,H,V,T>,H extends HeapDomain<H>,V extends ValueDomain<V>,T extends TypeDomain<T>> AnalysisState<A,H,V,T> semantics(AnalysisState<A,H,V,T> entryState,
                                                                                                                                                                                                                   InterproceduralAnalysis<A,H,V,T> interprocedural,
                                                                                                                                                                                                                   StatementStore<A,H,V,T> expressions)
                                                                                                                                                                                                            throws SemanticException

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 semantics(AnalysisState, InterproceduralAnalysis, StatementStore) of each nested Expression, saving the result of each call in expressions.

Type Parameters:

A - the type of AbstractState

H - the type of the HeapDomain

V - the type of the ValueDomain

T - the type of TypeDomain

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

getLocation

public CodeLocation getLocation()

Description copied from interface: CodeElement

Yields the location where this code element appears in the program.

Specified by:

getLocation in interface CodeElement

Returns:

the location where this code element appears in the program

compareTo

public int compareTo(Statement o)

Specified by:

compareTo in interface java.lang.Comparable<Statement>

getEvaluationPredecessor

public final Statement getEvaluationPredecessor()

Yields the Statement that is evaluated right before this one, such that querying for the entry state of this expression is equivalent to querying the exit state of the returned one. If this method returns null, then this is the first expression evaluated when an entire statement is evaluated.

Returns:

the previous statement, or null

getStatementEvaluatedBefore

public Statement getStatementEvaluatedBefore(Statement other)

Yields the Statement that precedes the given one, assuming that other is contained into this expression. If this method returns null, then other is the first expression evaluated when this statement is evaluated.

Parameters:

other - the other statement

Returns:

the previous statement, or null