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

Class RightToLeftEvaluation

java.lang.Object

it.unive.lisa.program.cfg.statement.evaluation.RightToLeftEvaluation

All Implemented Interfaces:

EvaluationOrder

public class RightToLeftEvaluation
extends java.lang.Object
implements EvaluationOrder

A right-to-left EvaluationOrder, evaluating expressions in reversed order.

Field Summary

Fields

Modifier and Type	Field	Description
static RightToLeftEvaluation	INSTANCE	The singleton instance of this class.

Method Summary

Modifier and Type	Method	Description
<A extends AbstractState<A>> AnalysisState<A>	bwdEvaluate(Expression[] subExpressions, AnalysisState<A> entryState, InterproceduralAnalysis<A> interprocedural, StatementStore<A> expressions, ExpressionSet[] computed)	Evaluates the given sub-expressions according to this order, but in reverse order and using the backward semantics.
<A extends AbstractState<A>> AnalysisState<A>	evaluate(Expression[] subExpressions, AnalysisState<A> entryState, InterproceduralAnalysis<A> interprocedural, StatementStore<A> expressions, ExpressionSet[] computed)	Evaluates the given sub-expressions according to this order.
int	first(int len)	Yields the index of the first sub-expression that has to be evaluated.
int	last(int len)	Yields the index of the last sub-expression that has to be evaluated.
int	next(int pos, int len)	Assuming that pos is the index of a sub-expression, yields the index of the sub-expression that has to be evaluated after the given one.
int	previous(int pos, int len)	Assuming that pos is the index of a sub-expression, yields the index of the sub-expression that has to be evaluated before the given one.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

INSTANCE

public static final RightToLeftEvaluation INSTANCE

The singleton instance of this class.

Method Detail

evaluate

public <A extends AbstractState<A>> AnalysisState<A> evaluate(Expression[] subExpressions,
                                                              AnalysisState<A> entryState,
                                                              InterproceduralAnalysis<A> interprocedural,
                                                              StatementStore<A> expressions,
                                                              ExpressionSet[] computed)
                                                       throws SemanticException

Description copied from interface: EvaluationOrder

Evaluates the given sub-expressions according to this order. This method will fill computed and subStates such that subStates[i] = subExpressions[i].semantics(); computed[i] = subStates[i].computedExpressions, while also setting the runtime types for the expressions left on the stack.

Specified by:

evaluate in interface EvaluationOrder

Type Parameters:

A - the type of AbstractState

Parameters:

subExpressions - the sub-expressions to evaluate

entryState - the state to use as starting point for the evaluation

interprocedural - the interprocedural analysis of the program to analyze

expressions - the cache where analysis states of intermediate expressions must be stored (this method is responsible for storing the results of the sub-expressions)

computed - an array containing, for each sub-expression, the symbolic expressions produced by its evaluation

Returns:

the last computed state, where the source expression can be evaluated

Throws:

SemanticException - if something goes wrong during the evaluation

bwdEvaluate

public <A extends AbstractState<A>> AnalysisState<A> bwdEvaluate(Expression[] subExpressions,
                                                                 AnalysisState<A> entryState,
                                                                 InterproceduralAnalysis<A> interprocedural,
                                                                 StatementStore<A> expressions,
                                                                 ExpressionSet[] computed)
                                                          throws SemanticException

Description copied from interface: EvaluationOrder

Evaluates the given sub-expressions according to this order, but in reverse order and using the backward semantics.

Specified by:

bwdEvaluate in interface EvaluationOrder

Type Parameters:

A - the type of AbstractState

Parameters:

subExpressions - the sub-expressions to evaluate

entryState - the state to use as starting point for the evaluation

interprocedural - the interprocedural analysis of the program to analyze

expressions - the cache where analysis states of intermediate expressions must be stored (this method is responsible for storing the results of the sub-expressions)

computed - an array containing, for each sub-expression, the symbolic expressions produced by its evaluation

Returns:

the last computed state, where the source expression can be evaluated

Throws:

SemanticException - if something goes wrong during the evaluation

previous

public int previous(int pos,
                    int len)

Description copied from interface: EvaluationOrder

Assuming that pos is the index of a sub-expression, yields the index of the sub-expression that has to be evaluated before the given one.

Specified by:

previous in interface EvaluationOrder

Parameters:

pos - the index of a sub-expression

len - the total number of sub-expressions

Returns:

the previous index (a negative value means that there is no previous sub-expression, that is, pos is the first that needs to be evaluated)

next

public int next(int pos,
                int len)

Description copied from interface: EvaluationOrder

Assuming that pos is the index of a sub-expression, yields the index of the sub-expression that has to be evaluated after the given one.

Specified by:

next in interface EvaluationOrder

Parameters:

pos - the index of a sub-expression

len - the total number of sub-expressions

Returns:

the next index (a negative value means that there is no next sub-expression, that is, pos is the last that needs to be evaluated)

first

public int first(int len)

Description copied from interface: EvaluationOrder

Yields the index of the first sub-expression that has to be evaluated.

Specified by:

first in interface EvaluationOrder

Parameters:

len - the total number of sub-expressions

Returns:

the index of the first expression to evaluate

last

public int last(int len)

Description copied from interface: EvaluationOrder

Yields the index of the last sub-expression that has to be evaluated.

Specified by:

last in interface EvaluationOrder

Parameters:

len - the total number of sub-expressions

Returns:

the index of the last expression to evaluate