Exception

Exception

[TC]

Why if an error is present no one of exception is write?
I create an array index exception for testing.

procedure Testo is
Begin
...
exception
                   when Error : Constraint_Error | Data_Error =>
                   Put ("Si ￜ verificato un errore: ");
                   Put_Line (Ada.Exceptions.Exception_Name(Error));
                   when Error : others=>
                   Put ("Si ￜ verificato un errore: ");
                   Put_Line (Ada.Exceptions.Exception_Name(Error));
                     raise;
end testo;

Re: Exception

[Pascal Obry]

TC a ï¿œcrit :
> Why if an error is present no one of exception is write?
> I create an array index exception for testing.
> 
> procedure Testo is
> Begin
> ....
> exception

Because the special Ada command "..." is equivalent to C "exit(0)", in
other words it says exit now and do not pass through the exception handlers.

Pascal.

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Re: Exception

[Martin Krischik]

TC wrote:

> Why if an error is present no one of exception is write?
> I create an array index exception for testing.


> procedure Testo is
> Begin
> ...
> exception
>                    when Error : Constraint_Error | Data_Error =>
>                    Put ("Si ￜ verificato un errore: ");
>                    Put_Line (Ada.Exceptions.Exception_Name(Error));
>                    when Error : others=>
>                    Put ("Si ￜ verificato un errore: ");
>                    Put_Line (Ada.Exceptions.Exception_Name(Error));
>                      raise;
> end testo;

One possibility: Only exceptions between begin and exception are handled. If
the exception happens between is and being it goes to the caller.

Note: this is especially important when dealing with task types.

Martin
-- 
mailto://krischik@users.sourceforge.net
Ada programming at: http://ada.krischik.com

Re: Exception

[Georg Bauhaus]

TC wrote:
> Why if an error is present no one of exception is write?

Which error is present in your program? Or which error
do you expect to be present?

> I create an array index exception for testing.

Could you give some details like the array's declaration,
how you used it, how you compiled the program (switches,etc.)?

exception

[alex]

How to i treat exception and redirect them inside the program ?

exception

[Pablo Campo]

I am a programmer of ADA and I use the Alsys Active ADA envirotment
version 5.3

I am making a proyect full of tasking and interrupts (for example I
manage the clock interrupt) and my problem is that  my program breaks
down in execution time and the only information  I recive is "Program
terminated. Unhandled exception".
Yesterday, I spent all the morning handling exceptions in all tasks and
subprograms but the result was the same.
�What can I do for obtain more information of the problem?

Nacho - A spanish enginier student.

Re: exception

[Corey Ashford]

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Pablo Campo wrote in message <363992D5.643F343E@biha01.ehu.es>...
>I am a programmer of ADA and I use the Alsys Active ADA envirotment
>version 5.3
>
>I am making a proyect full of tasking and interrupts (for example I
>manage the clock interrupt) and my problem is that  my program breaks
>down in execution time and the only information  I recive is "Program
>terminated. Unhandled exception".
>Yesterday, I spent all the morning handling exceptions in all tasks and
>subprograms but the result was the same.
>�What can I do for obtain more information of the problem?
>
>Nacho - A spanish enginier student.
>

It doesn't even tell you which exception occurred?  Wow... that's not
real helpful.

Perhaps the Alsys debugger has a way of setting a breakpoint when an
exception occurs.  You might look around for that in the debugger
user's manual (if there is one).

- Corey

Re: exception

[Jerry van Dijk]

Pablo Campo (jtacaezp@biha01.ehu.es) wrote:

: I am a programmer of ADA and I use the Alsys Active ADA envirotment
: version 5.3

: I am making a proyect full of tasking and interrupts (for example I
: manage the clock interrupt) and my problem is that  my program breaks
: down in execution time and the only information  I recive is "Program
: terminated. Unhandled exception".

Analyzing the problem requires a lot more information. Can you post a
small example program that shows this behaviour ?

Jerry.
-- 
-- Jerry van Dijk  | email: jdijk@acm.org
-- Leiden, Holland | member Team-Ada
-- Ada & Win32: http://stad.dsl.nl/~jvandyk

Re: exception

[Steve Quinlan]

Pablo Campo wrote:
> 
> I am a programmer of ADA and I use the Alsys Active ADA envirotment
> version 5.3
> 
> I am making a proyect full of tasking and interrupts (for example I
> manage the clock interrupt) and my problem is that  my program breaks
> down in execution time and the only information  I recive is "Program
> terminated. Unhandled exception".
> Yesterday, I spent all the morning handling exceptions in all tasks and
> subprograms but the result was the same.
> �What can I do for obtain more information of the problem?
> 
> Nacho - A spanish enginier student.
I don't understand how people can use some of these implementations
which make it so hard to figure out where an exception came from unless
you are in a debugger. OCS and Aonix for example dump out the exception
and a traceback in human readable format (unit/line #) to stdout if a
program dies with an unhandled exception. That symbol table is a small
price to pay for the ability to do problem determination.  

Best I can suggest is: Does that environment come with a debugger that
you can run the application under? If you've got hanlders in all the
tasks and it's still dying, maybe it's happening at elaboration outside
the scope of the task body handlers. You'd need a debugger that is
capable of breaking on exceptions during elaboration.