[Scilab-Dev] [Fwd: Re: Debug de Scipad]

[Enrico Segre]

                              From: 
fvogelnew1 at free.fr
                                To: 
Sylvestre Ledru
<sylvestre.ledru at inria.fr>
                                Cc: 
Bruno JOFRET
<bruno.jofret at inria.fr>, @free.fr,
Enrico Segre
<enrico.segre at weizmann.ac.il>
                           Subject: 
Re: Debug de Scipad
                              Date: 
Wed, 14 May 2008 23:38:26 +0200
(Thu, 00:38 IDT)


Selon Sylvestre Ledru <sylvestre.ledru at inria.fr>:
> A priori, on va pas remettre en place la réentrance du TCL (trop
> compliqué et pose trop de pb annexe).

Could you please develop your reasons? The above sounds quite short.
I can assure you that working around the new limitation introduced in
Scilab 5
is also very very complicated in Scipad.


> On va l'indiquer dans le CHANGES
> et proposer une solution alternative.
>
> Bruno a decrit sur le wiki comment le remplacer:
>
http://wiki.scilab.org/Tcl_Thread#head-e76a052af725f97db7a6bac94e3d88958fc10f77

As stated in previous emails, I already had a try in the past but I gave
up.
It's just toot difficult to do on a line by line basis.

Enrico has correctly explained why we had to use reentrance. In
particular,
there are very complex reentrant structures, needed to guarantee the
correct
execution order of ScilabEvaled instructions *mixed* with Scilab code.
Sync seq
does not help in this case, at least it didn't with the previous
interface.

I have already pointed you to proc checkendofdebug_bp in
SCI/modules/scipad/tcl/db_states.tcl for a nice example of the
gymnastics I had
to do, did you have a look? Really, did you? Please do. Now, how is this
translatable into non reentrant code? I'm not proficient enough to tell.

Honestly, handling this is a big big work. You're more or less asking
for a
rewrite of the debugger from scratch, because changing things on a per
line
basis copied/pasted on the wiki example will just not work.
I would probably need months to have only partial features in the
debugger if no
reentrant call would be available.
This is certainly not what you were hoping to hear, but this is just the
raw
truth.


> Est ce que tu pense que ca réglerait les pbs du débugger ?
> Si ça n'est pas le cas, tu aurais besoin de quoi pour pouvoir le
> régler ?

Enrico's proposal is a good idea I think.
Basically, being able to restore the reentrance behaviour of Scilab4 by
a
command would probably help.

Otherwise, I don't know. On one hand I tend to agree with the new
interface
being cleaner than the previous one, but on the other hand complying
with the
new limitation of this interface really is a huge work, believe me.

Your forgetting about reeentrance will also break existing features, see
a
recent example here:
http://groups.google.fr/group/comp.soft-sys.math.scilab/browse_thread/thread/d13da70c713b925a


> Sorry de t'envoyer ça des semaines après.

No problem, I have all my time.


Aside from the technical issue discussed here, I would like to move this
thread
to the dev mailing list. Other people may very well have useful ideas,
andit's a
good occasion to share and consult, isn't it?
Anybody having a concern with moving the discussion to a public place,
please
speak now.

Francois