[fpc-pascal] Exceptions in Library

[steveg]

On 30/03/15 16:46, leledumbo wrote:
>> As far as I can tell, exceptions propagate through to the main app -
>> (written with Lazarus in this case).
>> I would like to trap them directly within the library.
> // excp.pas
> library excp;
>
> {$mode objfpc}
>
> uses sysutils;
>
> procedure p;
> begin
>    try
>      raise exception.create('an exception')
>    except
>      on e: exception do
>        writeln(e.message);
>    end;
> end;
>
> exports p;
>
> end.
>
> // test.pas
> procedure p; external 'excp';
>
> begin p end.
>
> run with:
> $ LD_LIBRARY_PATH=. ./test
>
> you should get:
> an exception
>
> tested on ManjaroLinux 64-bit.
>
Tested this, and you are correct - it captures it correctly
After further testing - It would seem to capture some but not others ?

(contrived example - I know not to directly call a control within a library)
this doesnt seem to be trapped - drops thru to main app

   try
     Str1 := TControl(0).Name;
   except
     on e: exception do
       writeln(e.message);
   end;

Would this suggest a different signal attachment is necessary ?

Thanks