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

Class NaryStatement

java.lang.Object

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

it.unive.lisa.program.cfg.statement.NaryStatement

All Implemented Interfaces:

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

Direct Known Subclasses:

BinaryStatement, TernaryStatement, UnaryStatement

public abstract class NaryStatement
extends Statement

A generic statement with n sub-expressions.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	NaryStatement(CFG cfg, CodeLocation location, java.lang.String constructName, EvaluationOrder order, Expression... subExpressions)	Builds the statement, happening at the given location in the program.
protected	NaryStatement(CFG cfg, CodeLocation location, java.lang.String constructName, Expression... subExpressions)	Builds the statement, happening at the given location in the program.

Method Summary

Modifier and Type	Method	Description
<V> boolean	accept(GraphVisitor<CFG,Statement,Edge,V> visitor, V tool)	Accepts the given GraphVisitor.
<A extends AbstractState<A>> AnalysisState<A>	backwardSemantics(AnalysisState<A> exitState, InterproceduralAnalysis<A> interprocedural, StatementStore<A> expressions)	Semantics of an n-ary statements is evaluated by computing the semantics of its sub-expressions, in the specified order, using the analysis state from each sub-expression's computation as entry state for the next one.
<A extends AbstractState<A>> AnalysisState<A>	backwardSemanticsAux(InterproceduralAnalysis<A> interprocedural, AnalysisState<A> state, ExpressionSet[] params, StatementStore<A> expressions)	Computes the backward semantics of the statement, after the semantics of all sub-expressions have been computed.
protected int	compareSameClass(Statement o)	Auxiliary method for Statement.compareTo(Statement) that can safely assume that the two statements happen at the same CodeLocation and are instances of the same class.
protected abstract int	compareSameClassAndParams(Statement o)	Auxiliary method for Statement.compareTo(Statement) that can safely assume that the two statements happen at the same CodeLocation, are instances of the same class, and have the same parameters according to their implementation of Statement.compareTo(Statement).
boolean	equals(java.lang.Object obj)
<A extends AbstractState<A>> AnalysisState<A>	forwardSemantics(AnalysisState<A> entryState, InterproceduralAnalysis<A> interprocedural, StatementStore<A> expressions)	Semantics of an n-ary statements is evaluated by computing the semantics of its sub-expressions, in the specified order, using the analysis state from each sub-expression's computation as entry state for the next one.
abstract <A extends AbstractState<A>> AnalysisState<A>	forwardSemanticsAux(InterproceduralAnalysis<A> interprocedural, AnalysisState<A> state, ExpressionSet[] params, StatementStore<A> expressions)	Computes the forward semantics of the statement, after the semantics of all sub-expressions have been computed.
java.lang.String	getConstructName()	Yields the name of the native construct represented by this statement.
EvaluationOrder	getOrder()	Yields the EvaluationOrder of the sub-expressions.
Statement	getStatementEvaluatedAfter(Statement other)	Yields the Statement that follows the given one, assuming that other is contained into this statement.
Statement	getStatementEvaluatedBefore(Statement other)	Yields the Statement that precedes the given one, assuming that other is contained into this statement.
Expression[]	getSubExpressions()	Yields the sub-expressions of this statement.
int	hashCode()
java.lang.String	toString()

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

compareTo, getCFG, getEvaluationPredecessor, getEvaluationSuccessor, getLocation, stopsExecution, throwsError

Methods inherited from class java.lang.Object

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

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

getProgram

Constructor Detail

NaryStatement

protected NaryStatement(CFG cfg,
                        CodeLocation location,
                        java.lang.String constructName,
                        Expression... subExpressions)

Builds the statement, happening at the given location in the program. The EvaluationOrder is LeftToRightEvaluation.

Parameters:

cfg - the cfg that this expression belongs to

location - the location where the expression is defined within the program

constructName - the name of the construct represented by this expression

subExpressions - the sub-expressions to be evaluated left-to-right

NaryStatement

protected NaryStatement(CFG cfg,
                        CodeLocation location,
                        java.lang.String constructName,
                        EvaluationOrder order,
                        Expression... subExpressions)

Builds the statement, 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 program

constructName - the name of the construct represented by this expression

order - the evaluation order of the sub-expressions

subExpressions - the sub-expressions

Method Detail

getConstructName

public final java.lang.String getConstructName()

Yields the name of the native construct represented by this statement.

Returns:

the name of the construct

getSubExpressions

public final Expression[] getSubExpressions()

Yields the sub-expressions of this statement.

Returns:

the sub-expressions

getOrder

public EvaluationOrder getOrder()

Yields the EvaluationOrder of the sub-expressions.

Returns:

the evaluation order

accept

public final <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

toString

public java.lang.String toString()

Specified by:

toString in class Statement

getStatementEvaluatedBefore

public Statement getStatementEvaluatedBefore(Statement other)

Description copied from class: Statement

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

Overrides:

getStatementEvaluatedBefore in class Statement

Parameters:

other - the other statement

Returns:

the previous statement, or null

getStatementEvaluatedAfter

public Statement getStatementEvaluatedAfter(Statement other)

Description copied from class: Statement

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

Overrides:

getStatementEvaluatedAfter in class Statement

Parameters:

other - the other statement

Returns:

the next statement, or null

hashCode

public int hashCode()

Overrides:

hashCode in class Statement

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class Statement

compareSameClass

protected int compareSameClass(Statement o)

Description copied from class: Statement

Auxiliary method for Statement.compareTo(Statement) that can safely assume that the two statements happen at the same CodeLocation and are instances of the same class.

Specified by:

compareSameClass in class Statement

Parameters:

o - the other statement

Returns:

a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object

compareSameClassAndParams

protected abstract int compareSameClassAndParams(Statement o)

Auxiliary method for Statement.compareTo(Statement) that can safely assume that the two statements happen at the same CodeLocation, are instances of the same class, and have the same parameters according to their implementation of Statement.compareTo(Statement).

Parameters:

o - the other statement

Returns:

a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object

forwardSemantics

public <A extends AbstractState<A>> AnalysisState<A> forwardSemantics(AnalysisState<A> entryState,
                                                                      InterproceduralAnalysis<A> interprocedural,
                                                                      StatementStore<A> expressions)
                                                               throws SemanticException

Semantics of an n-ary statements is evaluated by computing the semantics of its sub-expressions, in the specified order, using the analysis state from each sub-expression's computation as entry state for the next one. Then, the semantics of the statement itself is evaluated.

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

Specified by:

forwardSemantics in class Statement

Type Parameters:

A - the type of AbstractState

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

forwardSemanticsAux

public abstract <A extends AbstractState<A>> AnalysisState<A> forwardSemanticsAux(InterproceduralAnalysis<A> interprocedural,
                                                                                  AnalysisState<A> state,
                                                                                  ExpressionSet[] params,
                                                                                  StatementStore<A> expressions)
                                                                           throws SemanticException

Computes the forward semantics of the statement, after the semantics of all sub-expressions have been computed. Meta variables from the sub-expressions will be forgotten after this call returns.

Type Parameters:

A - the type of AbstractState

Parameters:

interprocedural - the interprocedural analysis of the program to analyze

state - the state where the statement is to be evaluated

params - the symbolic expressions representing the computed values of the sub-expressions of this statement

expressions - the cache where analysis states of intermediate expressions are stored and that can be accessed to query for post-states of parameters expressions

Returns:

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

Throws:

SemanticException - if something goes wrong during the computation

backwardSemantics

public <A extends AbstractState<A>> AnalysisState<A> backwardSemantics(AnalysisState<A> exitState,
                                                                       InterproceduralAnalysis<A> interprocedural,
                                                                       StatementStore<A> expressions)
                                                                throws SemanticException

Semantics of an n-ary statements is evaluated by computing the semantics of its sub-expressions, in the specified order, using the analysis state from each sub-expression's computation as entry state for the next one. Then, the semantics of the statement itself is evaluated.

Computes the backward 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.forwardSemantics(AnalysisState, InterproceduralAnalysis, StatementStore) of each nested Expression, saving the result of each call in expressions. By default, this method delegates to Statement.forwardSemantics(AnalysisState, InterproceduralAnalysis, StatementStore), as it is fine for most atomic statements. One should redefine this method if a statement's semantics is composed of a series of smaller operations.

Overrides:

backwardSemantics in class Statement

Type Parameters:

A - the type of AbstractState

Parameters:

exitState - the exit 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

backwardSemanticsAux

public <A extends AbstractState<A>> AnalysisState<A> backwardSemanticsAux(InterproceduralAnalysis<A> interprocedural,
                                                                          AnalysisState<A> state,
                                                                          ExpressionSet[] params,
                                                                          StatementStore<A> expressions)
                                                                   throws SemanticException

Computes the backward semantics of the statement, after the semantics of all sub-expressions have been computed. Meta variables from the sub-expressions will be forgotten after this call returns. By default, this method delegates to forwardSemanticsAux(InterproceduralAnalysis, AnalysisState, ExpressionSet[], StatementStore), as it is fine for most atomic statements. One should redefine this method if a statement's semantics is composed of a series of smaller operations.

Type Parameters:

A - the type of AbstractState

Parameters:

interprocedural - the interprocedural analysis of the program to analyze

state - the state where the statement is to be evaluated

params - the symbolic expressions representing the computed values of the sub-expressions of this statement

expressions - the cache where analysis states of intermediate expressions are stored and that can be accessed to query for post-states of parameters expressions

Returns:

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

Throws:

SemanticException - if something goes wrong during the computation