Re: [Patch, Fortran] PR fortran/44709: Clean up local variables with try-finally

[Mikael Morin <mikael dot morin at sfr dot fr>]

Le 15.07.2010 11:07, Daniel Kraft a écrit :
> Hi all,
>
> the attached patch does what I wrote about in
> http://gcc.gnu.org/ml/fortran/2010-07/msg00058.html. Briefly, I modified
> gfc_trans_deferred_vars and its callees such that init and cleanup code
> (like memory allocation / deallocation) is collected seperately rather
> than wrapped around the function body directly; this is then used to do
> the clean-up with a try-finally middle-end expression, so that all exits
> safely do the cleanup automagically. Which fixes the wrong-code /
> memory-leak part of PR 44709.
>
> Currently, multiple returns from procedures are handled via a jump to a
> label at the end of the function, from which on the cleanup was done
> before (in order to work around the problem in the PR for BLOCKs). I
> think that this may no longer be needed in fact now (am I right? Or is
> there another reason why we want only a single exit point from all
> procedures?).
The testsuite will tell ;-)

> I'll work on a second patch to remove this (if it works
> out) as follow-up. Hopefully this can help the middle-end a little bit
> and make the code-structure clearer to it.
>
> Most of the attached patch are more or less mechanical changes (except
> the code directly working with gfc_wrapped_block); I used to introduce a
> mistake there (which was fortunately caught by a lot of regressions),
> but please take a careful look at all those.
I don't swear I haven't overlooked anything, but from my point of view, 
it looks good.
> No regressions on GNU/Linux-x86-32, and additionally valgrind shows no
> longer any memory leaks for code like that in the PR (and the tree-dump
> also looks fine). This was with SVN trunk some days ago, though, so I'm
> at the moment building and testing with a fresh update.
>
> Ok for trunk if no failures with that, either?
I guess there is no way to test this in the testsuite.
OK then.

Thanks for it,
Mikael