comparing of mix,max values of two sub types in Ada using ASIS

Question

I want to compare min, max of values of two subtypes. In Ada language it is possible to assign between two different subtypes, for example

procedure Example_1 is
   subtype Type_1 is Integer range 0 .. 10;
   subtype Type_2 is Integer range 0 .. 30;
   A : Type_1 := 0;
   B : Type_2 := 12;
begin
   A := B;
end Example_1;

At run time A := B can give range overflow error. In ASIS, is it possible to compare subtypes, min/max values of subtypes (integer, real, enumeration types) so that I can identify overflow problem before run-time?

score 2 · Answer 1 · answered Jul 15 '18 at 14:25

2

The compiler detects this problem when compiled with -gnatVa -gnat12

answered Jul 15 '18 at 14:25

Jim Rogers

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score 1 · Answer 2 · answered Jul 21 '18 at 19:22

1

Yes, it is possible to check this with ASIS.

See the answer to this question for how to extract 'First and 'Last for a subtype.

answered Jul 21 '18 at 19:22

Jacob Sparre Andersen

6,733
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Thank you for your answer sir. I getting exception in "sub_constraint" call for enumeration type. Please let me know how to overcome this problem. – Lakshman Naik Jul 24 '18 at 03:43
I can't help you with that without a bit more context. Maybe you should compose a new question, demonstrating how far you've got. - Or just update this one with additional context. – Jacob Sparre Andersen Jul 25 '18 at 12:11

comparing of mix,max values of two sub types in Ada using ASIS

2 Answers2