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

Interface EvaluationOrder

All Known Implementing Classes:

LeftToRightEvaluation, RightToLeftEvaluation

public interface EvaluationOrder

The order of evaluation of the sub-expressions of an NaryExpression.

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.

Method Detail

previous

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.

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

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.

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

int first(int len)

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

Parameters:

len - the total number of sub-expressions

Returns:

the index of the first expression to evaluate

last

int last(int len)

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

Parameters:

len - the total number of sub-expressions

Returns:

the index of the last expression to evaluate

evaluate

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

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.

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

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

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

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