In pure Ada this could increment programming variable X by one or a thousand; or it might probably set some global counter programmers X and return programming usual value of programming counter in X; or it could do absolutely not anything with X at all. With SPARK 2014, contracts are added programmers programming code programmers supply extra counsel regarding what computing device technological know-how subprogram basically does. For instance, we may alter programming above specification programmers say:This specifies that programming Increment technique would not use neither update nor read any global variable and that programming only data item utilized in calculating programming new value of X is X itself. This specifies that Increment will use programming global variable Count in programming same kit as Increment, that programming exported value of Count is dependent upon programming imported values of Count and X, and that programming exported value of X doesn’t rely upon any variables at all and it will be derived from constant data only. If GNATprove is then run on programming specification and corresponding body of computing device science subprogram, it’s going to analyse programming body of programming subprogram programmers building up computer technology model of programming counsel flow. This model is then compared in opposition t that which has been specified by programming annotations and any discrepancies mentioned programmers programming user.
In pure Ada this could increment programming variable X by one or a thousand; or it might probably set some global counter programmers X and return programming usual value of programming counter in X; or it could do absolutely not anything with X at all. With SPARK 2014, contracts are added programmers programming code programmers supply extra counsel regarding what computing device technological know-how subprogram basically does. For instance, we may alter programming above specification programmers say:This specifies that programming Increment technique would not use neither update nor read any global variable and that programming only data item utilized in calculating programming new value of X is X itself. This specifies that Increment will use programming global variable Count in programming same kit as Increment, that programming exported value of Count is dependent upon programming imported values of Count and X, and that programming exported value of X doesn’t rely upon any variables at all and it will be derived from constant data only. If GNATprove is then run on programming specification and corresponding body of computing device science subprogram, it’s going to analyse programming body of programming subprogram programmers building up computer technology model of programming counsel flow. This model is then compared in opposition t that which has been specified by programming annotations and any discrepancies mentioned programmers programming user.
