From: Peter Brooks <peter.h.m.brooks@gmail.com>
Subject: Range check for type 'Integer'
Date: Mon, 17 Jun 2013 03:57:26 -0700 (PDT)
Date: 2013-06-17T03:57:26-07:00 [thread overview]
Message-ID: <7f33982d-3bcf-452e-a3b3-3a0a28505ff1@x20g2000vbe.googlegroups.com> (raw)
I may be confused about this, but I don't understand the behaviour of
a very simple Ada program.
Firstly, this program does what I do expect:
"
procedure Compute_Loop is
type fred is range -3276732787230772307 .. 3276732787230772307;
procedure Double(Item : in out fred) is
begin -- procedure Double.
Item := Item * 2;
end Double;
X : fred := 1; -- Local variable X of type fred.
begin -- procedure Compute_loop
loop
Put("This is ");
Put(Integer(X));
New_Line;
Double(X);
end loop;
end Compute_Loop;
"
Output:
...
This is 268435456
This is 536870912
This is 1073741824
This is
raised CONSTRAINT_ERROR : compute_loop.adb:19 range check failed
Exactly the same program, but using type 'Integer' instead for 'fred'
gives:
...
This is 134217728
This is 268435456
This is 536870912
This is 1073741824
This is -2147483648
This is 0
This is 0
This is 0
This is 0
This is 0
This is 0
This is 0
This is 0
..... [forever]
So the 'Integer' has rolled over to negative and then rolled back to 0
- but with no run-time error.
Why is there no range check error on type Integer?
next reply other threads:[~2013-06-17 10:57 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-17 10:57 Peter Brooks [this message]
2013-06-17 11:23 ` Range check for type 'Integer' Simon Clubley
2013-06-17 11:54 ` Simon Wright
2013-06-17 12:55 ` Peter Brooks
2013-06-17 13:28 ` Shark8
2013-06-17 13:45 ` Peter Brooks
2013-06-17 21:16 ` Shark8
2013-06-18 10:48 ` Stephen Leake
2013-06-17 12:46 ` Dmitry A. Kazakov
2013-06-17 13:23 ` Bug in 'gnatmake' (Was: Range check for type 'Integer') Jacob Sparre Andersen
2013-06-17 13:32 ` Bug in 'gnatmake' Jacob Sparre Andersen
2013-06-17 16:50 ` Bug in 'gnatmake' (Was: Range check for type 'Integer') Robert A Duff
2013-06-17 19:15 ` Peter Brooks
2013-06-17 21:09 ` Shark8
2013-06-17 21:22 ` Jeffrey Carter
2013-06-18 1:21 ` Peter Brooks
2013-06-18 6:33 ` Jeffrey Carter
2013-06-18 7:29 ` Georg Bauhaus
2013-06-17 18:49 ` Bug in 'gnatmake' Simon Wright
2013-06-18 9:09 ` Elaboration order handling (Was: Bug in 'gnatmake') Jacob Sparre Andersen
2013-06-18 17:09 ` Robert A Duff
2013-06-18 22:52 ` Adam Beneschan
2013-06-19 1:21 ` Jeffrey Carter
2013-06-19 12:38 ` Robert A Duff
2013-06-19 20:43 ` Georg Bauhaus
2013-06-20 0:37 ` Robert A Duff
2013-06-20 19:56 ` Georg Bauhaus
2013-06-19 12:22 ` Robert A Duff
2013-06-19 15:46 ` Adam Beneschan
2013-06-19 16:41 ` Robert A Duff
2013-06-19 20:47 ` Georg Bauhaus
2013-06-19 21:36 ` Adam Beneschan
2013-06-20 0:57 ` Robert A Duff
2013-06-20 1:09 ` Jeffrey Carter
2013-06-20 2:29 ` Adam Beneschan
2013-06-20 6:08 ` Jeffrey Carter
2013-06-20 15:11 ` Robert A Duff
2013-06-21 5:26 ` Jeffrey Carter
2013-06-21 15:48 ` Adam Beneschan
2013-06-21 18:35 ` Jeffrey Carter
2013-06-21 19:10 ` Robert A Duff
2013-06-21 21:27 ` Jeffrey Carter
2013-06-21 20:43 ` Adam Beneschan
2013-06-21 21:44 ` Jeffrey Carter
2013-06-21 23:47 ` Robert A Duff
2013-06-23 14:43 ` AdaMagica
2013-06-21 18:58 ` null declarative parts (was: Re: Elaboration order handling) Robert A Duff
2013-06-21 20:42 ` null declarative parts Georg Bauhaus
2013-06-20 2:11 ` Elaboration order handling (Was: Bug in 'gnatmake') Adam Beneschan
2013-06-20 14:44 ` Robert A Duff
2013-06-20 11:24 ` G.B.
2013-06-20 15:23 ` Robert A Duff
2013-06-19 21:00 ` Georg Bauhaus
2013-06-19 22:26 ` Randy Brukardt
2013-06-20 0:31 ` Robert A Duff
2013-06-20 21:36 ` Randy Brukardt
2013-06-19 13:07 ` Bill Findlay
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