*PING* Re: [PATCH] PR fortran/100950 - ICE in output_constructor_regular_field, at varasm.c:5514

[Harald Anlauf <anlauf@gmx.de>]

*Ping*

> Gesendet: Dienstag, 03. August 2021 um 23:17 Uhr
> Von: "Harald Anlauf" <anlauf@gmx.de>
> An: "Harald Anlauf" <anlauf@gmx.de>
> Cc: "Tobias Burnus" <Tobias_Burnus@mentor.com>, "Bernhard Reutner-Fischer" <rep.dot.nop@gmail.com>, "Harald Anlauf via Gcc-patches" <gcc-patches@gcc.gnu.org>, "fortran" <fortran@gcc.gnu.org>
> Betreff: Re: [PATCH] PR fortran/100950 - ICE in output_constructor_regular_field, at varasm.c:5514
>
> Here's now my third attempt to fix this PR, taking into account
> the comments by Tobias and Bernhard.
> 
> > > On 10.06.21 20:52, Harald Anlauf via Fortran wrote:
> > > > +static bool
> > > > +substring_has_constant_len (gfc_expr *e)
> > > > +{
> > > > +  ptrdiff_t istart, iend;
> > > > +  size_t length;
> > > > +  bool equal_length = false;
> > > > +
> > > > +  if (e->ts.type != BT_CHARACTER
> > > > +      || !e->ref
> > > > +      || e->ref->type != REF_SUBSTRING
> > > 
> > > Is there a reason why you do not handle:
> > > 
> > > type t
> > >    character(len=5) :: str1
> > >    character(len=:), allocatable :: str2
> > > end type
> > > type(t) :: x
> > > 
> > > allocate(x%str2, source="abd")
> > > if (len (x%str)) /= 1) ...
> > > if (len (x%str2(1:2) /= 2) ...
> > > etc.
> > > 
> > > Namely: Search the last_ref = expr->ref->next->next ...?
> > > and then check that lastref?
> 
> The mentioned search is now implemented.
> 
> Note, however, that gfc_simplify_len still won't handle neither
> deferred strings nor their substrings.
> 
> I think there is nothing to simplify at compile time here.  Otherwise
> there would be a conflict/inconsistency with type parameter inquiry,
> see F2018:9.4.5(2):
> 
> "A deferred type parameter of a pointer that is not associated or
> of an unallocated allocatable variable shall not be inquired about."
> 
> > >    * * *
> > > 
> > > Slightly unrelated: I think the following does not violate
> > > F2018's R916 / C923 – but is rejected, namely:
> > >    R916  type-param-inquiry  is  designator % type-param-name
> > > the latter is 'len' or 'kind' for intrinsic types. And:
> > >    R901  designator is ...
> > >                     or substring
> > > But
> > > 
> > > character(len=5) :: str
> > > print *, str(1:3)%len
> > > end
> > > 
> > > fails with
> > > 
> > >      2 | print *, str(1:3)%len
> > >        |                  1
> > > Error: Syntax error in PRINT statement at (1)
> > > 
> > > 
> > > Assuming you don't want to handle it, can you open a new PR?
> > > Thanks!
> 
> I tried to look into this, but there appear to be several unrelated
> issues requiring a separate treatment.  I therefore opened:
> 
>   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101735
> 
> > > > +  istart = gfc_mpz_get_hwi (e->ref->u.ss.start->value.integer);
> > > > +  iend = gfc_mpz_get_hwi (e->ref->u.ss.end->value.integer);
> > > > +  length = gfc_mpz_get_hwi (e->ref->u.ss.length->length->value.integer);
> > > > +
> > > > +  if (istart <= iend)
> > > > +    {
> > > > +      if (istart < 1)
> > > > +     {
> > > > +       gfc_error ("Substring start index (%ld) at %L below 1",
> > > > +                  (long) istart, &e->ref->u.ss.start->where);
> > > 
> > > As mentioned by Bernhard, you could use HOST_WIDE_INT_PRINT_DEC.
> > > 
> > > (It probably only matters on Windows which uses long == int = 32bit for
> > > strings longer than INT_MAX.)
> 
> Done.
> 
> The updated patch regtests fine.  OK?
> 
> Thanks,
> Harald
> 
> 
> Fortran - simplify length of substring with constant bounds
> 
> gcc/fortran/ChangeLog:
> 
> 	PR fortran/100950
> 	* simplify.c (substring_has_constant_len): New.
> 	(gfc_simplify_len): Handle case of substrings with constant
> 	bounds.
> 
> gcc/testsuite/ChangeLog:
> 
> 	PR fortran/100950
> 	* gfortran.dg/pr100950.f90: New test.
> 
>