Re: [PATCH,FORTRAN 00/29] Move towards stringpool, part 1

[Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>]

Hi all, Janne!

On Wed, 19 Sep 2018 16:40:01 +0200
Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> wrote:
> On Fri, 7 Sep 2018 at 10:07, Bernhard Reutner-Fischer
> <rep.dot.nop@gmail.com> wrote:
> >
> > On Wed, 5 Sep 2018 at 20:57, Janne Blomqvist <blomqvist.janne@gmail.com> wrote:  
> > >
> > > On Wed, Sep 5, 2018 at 5:58 PM Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> wrote:  
> >  
> > >> Bootstrapped and regtested on x86_64-foo-linux.
> > >>
> > >> I'd appreciate if someone could double check for regressions on other
> > >> setups. Git branch:
> > >> https://gcc.gnu.org/git/?p=gcc.git;a=log;h=refs/heads/aldot/fortran-fe-stringpool
> > >>
> > >> Ok for trunk?  
> > >
> > >
> > > Hi,
> > >
> > > this is quite an impressive patch set. I have looked through all the patches, and on the surface they all look ok.  
> >
> > Thanks alot for your appreciation!  
> > >
> > > Unfortunately I don't have any exotic target to test on either, so I think you just have to commit it and check for regression reports. Though I don't see this set doing anything which would work differently on other targets, but you never know..
> > >
> > > I'd say wait a few days in case anybody else wants to comment on it, then commit it to trunk.  

Unfortunately I never got to commit it.

Are you still OK with this series?

Iff so, i will refresh it for gcc-14 stage1. I would formally resubmit
the series for approval then, of course, for good measure.

It will need some small adjustments since coarrays were added
afterwards and a few other spots were changed since then.

Note that after your OK i fixed the problem described below with this
patch
https://inbox.sourceware.org/gcc-patches/20180919225533.20009-1-rep.dot.nop@gmail.com/
and so i think this "[PATCH,FORTRAN v2] Use stringpool on loading
module symbols" was not formally OKed yet, FWIW. I believe that this v2 worked flawlessly.
Note, however, that by adding/changing module names of symbols in the
module files, this will (i think / fear) require a bump of the module
version if we are honest. Ultimately that was the reason why i did not
push the series back then.

Link to the old series:
https://inbox.sourceware.org/gcc-patches/20180905145732.404-1-rep.dot.nop@gmail.com/

thanks and cheers,

> >
> > Upon further testing i encountered a regression in module writing,
> > manifesting itself in a failure to compile ieee_8.f90 (and only this).  
> 
> > Sorry for that, I'll have another look during the weekend.  
> 
> so in free_pi_tree we should not free true_name nor module:
> 
> @@ -239,12 +239,6 @@ free_pi_tree (pointer_info *p)
>    free_pi_tree (p->left);
>    free_pi_tree (p->right);
> 
> -  if (iomode == IO_INPUT)
> -    {
> -      XDELETEVEC (p->u.rsym.true_name);
> -      XDELETEVEC (p->u.rsym.module);
> -    }
> -
>    free (p);
>  }
> 
> This fixes the module writing but leaks, obviously.
> Now the reason why i initially did not use mio_pool_string for both
> rsym.module and rsym.true_name was that mio_pool_string sets the name
> to NULL if the string is empty.
> Currently these are read by read_string() [which we should get rid of
> entirely, the 2 mentioned fields are the last two who use
> read_string()] which does not nullify the empty string but returns
> just the pointer. For e.g. ieee_8.f90 using mio_pool_string gives us a
> NULL module which leads to gfc_use_module -> load_needed ->
> gfc_find_symbol -> gfc_find_sym_tree -> gfc_find_symtree which tries
> to c = strcmp (name, st->name); where name is NULL.
> 
> The main culprits seem to be class finalization wrapper variables so
> i'm adding modules to those now.
> Which leaves me with regressions like allocate_with_source_14.f03.
> "Fixing" these by falling back to gfc_current_ns->proc_name->name in
> load_needed for !ns->proc_name if the rsym->module is NULL seems to
> work.
> 
> Now there are a number of issues with names of fixups. Like the 9 in e.g.:
> 
> $ zcat /tmp/n/m.mod | egrep -v "^(\(\)|\(\(\)|$)"
> GFORTRAN module version '15' created from generic_27.f90
> (('testif' 'm' 2 3))
> (4 'm' 'm' '' 1 ((MODULE UNKNOWN-INTENT UNKNOWN-PROC UNKNOWN UNKNOWN 0 0)
> 3 'test1' 'm' '' 1 ((PROCEDURE UNKNOWN-INTENT MODULE-PROC DECL UNKNOWN 0
> 0 FUNCTION) () (REAL 4 0 0 0 REAL ()) 5 0 (6) () 3 () () () 0 0)
> 2 'test2' 'm' '' 1 ((PROCEDURE UNKNOWN-INTENT MODULE-PROC DECL UNKNOWN 0
> 0 FUNCTION ARRAY_OUTER_DEPENDENCY) () (REAL 4 0 0 0 REAL ()) 7 0 (8) ()
> 2 () () () 0 0)
> 6 'obj' '' '' 5 ((VARIABLE UNKNOWN-INTENT UNKNOWN-PROC UNKNOWN UNKNOWN 0
> 0 DUMMY) () (REAL 4 0 0 0 REAL ()) 0 0 () () 0 () () () 0 0)
> 8 'pr' '' '' 7 ((PROCEDURE UNKNOWN-INTENT DUMMY-PROC UNKNOWN UNKNOWN 0 0
> EXTERNAL DUMMY FUNCTION PROCEDURE ARRAY_OUTER_DEPENDENCY) () (REAL 4 9 0
> 0 REAL ()) 0 0 () () 8 () () () 0 0)
> 9 '' '' '' 7 ((PROCEDURE UNKNOWN-INTENT UNKNOWN-PROC UNKNOWN UNKNOWN 0 0
> FUNCTION) () (REAL 4 0 0 0 REAL ()) 0 0 () () 0 () () () 0 0)
> )
> ('m' 0 4 'test1' 0 3 'test2' 0 2)
> 
> which is a bit of a complication since we need them to verify proper
> interface types and attributes etc, etc.
> generic_27.f90 would then warn in check_proc_interface() that
> "Interface %qs at %L must be explicit".
> To bypass this warning i suggest to flag these as artificial like so:
> @@ -6679,10 +6683,12 @@ match_procedure_decl (void)
>             return MATCH_ERROR;
>           sym->ts.interface = gfc_new_symbol ("", gfc_current_ns);
>           sym->ts.interface->ts = current_ts;
>           sym->ts.interface->attr.flavor = FL_PROCEDURE;
>           sym->ts.interface->attr.function = 1;
> +         /* Suppress warnings about explicit interface */
> +         sym->ts.interface->attr.artificial = 1;
>           sym->attr.function = 1;
>           sym->attr.if_source = IFSRC_UNKNOWN;
>         }
> 
>        if (gfc_match (" =>") == MATCH_YES)
> @@ -6818,10 +6824,12 @@ match_ppc_decl (void)
>           c->ts.interface = gfc_new_symbol ("", gfc_current_ns);
>           c->ts.interface->result = c->ts.interface;
>           c->ts.interface->ts = ts;
>           c->ts.interface->attr.flavor = FL_PROCEDURE;
>           c->ts.interface->attr.function = 1;
> +         /* Suppress warnings about explicit interface */
> +         c->ts.interface->attr.artificial = 1;
>           c->attr.function = 1;
>           c->attr.if_source = IFSRC_UNKNOWN;
>         }
> 
>        if (gfc_match (" =>") == MATCH_YES)
> 
> and then not exclude ""-names but attr.artificial for the "must be
> explicit" warning. This works fine.
> 
> Another spot where we encounter trouble with NULL module in the sym is
> generic_1.f90 where we would be unable to distinguish interface sub
> arguments during true_name lookup.
> We find x in true names and consequently use this one sym for both the
> REAL as well as the INTEGER variable which of course doesn't work when
> resolving.
> As it turns out we get away with punting true_name lookup if the module is NULL.
> 
> The next hintch are unlimited polymorphic component class containers
> as in select_type_36.f03 when used in module context.
> gfc_find_gsymbol() around the "upe" really wants a module that is
> non-NULL which we luckily have at hand. This just extends the
> proc_name-hack.
> 
> @@ -4061,6 +4061,10 @@ gfc_match_decl_type_spec (gfc_typespec *ts, int
> implicit_flag)
>               upe->refs++;
>               upe->ts.type = BT_VOID;
>               upe->attr.unlimited_polymorphic = 1;
> +             /* Make sure gfc_find_gsymbol sees a (non-NULL) name to
> +              * search for by plugging in some module name.  */
> +             if (gfc_current_ns->proc_name != NULL)
> +               upe->module = gfc_current_ns->proc_name->name;
>               /* This is essential to force the construction of
>                  unlimited polymorphic component class containers.  */
>               upe->attr.zero_comp = 1;
> 
> The area of true_name and pi_root handling is a bit unpleasant to work
> with, i must admit. But then i do not volunteer to rip it all out ;)
> I think we will be able to remove some of these proc_name-hacks as
> soon as we switch the symbol finding to pointer comparison, at least.
> 
> I'm cleaning up the above for a final test and will send it as
> alternative, extended approach intended to replace the
> "[PATCH,FORTRAN 25/29] Use stringpool on loading module symbols" (
> https://gcc.gnu.org/ml/fortran/2018-09/msg00039.html )
> 
> patch, fwiw.
> 
> thanks,