[PATCH] PR fortran/99112 - [11 Regression] ICE with runtime diagnostics for SIZE intrinsic function

[Tobias Burnus]

Hi Harald, hi Paul,

On 13.03.21 09:58, Paul Richard Thomas via Fortran wrote:
> I am not sure of the etiquette for this - it looks OK to me :-)

:-)

On Fri, 12 Mar 2021 at 21:20, Harald Anlauf via Fortran 
<fortran@gcc.gnu.org>

> the addition of runtime checks for the SIZE intrinsic created a regression
> that showed up for certain CLASS arguments to procedures.  Paul did most of
> the work (~ 99%), but asked me to dig into an issue with an inappropriately
> selected error message.  This actually turned out to be a simple one-liner
> on top of Paul's patch.
>
> Regtested on x86_64-pc-linux-gnu.  OK for mainline?

The procedure-call patch looks good to me, except for:
> --- a/gcc/fortran/trans-expr.c
> +++ b/gcc/fortran/trans-expr.c
> @@ -6662,6 +6662,7 @@ gfc_conv_procedure_call (gfc_se * se, gfc_symbol * sym,
> [...]
> +	  tree temp;
> ...
> -	      tmp = parmse.expr;
> +	      if (fsym && fsym->ts.type == BT_CLASS)
> +		{
> +		  temp = build_fold_indirect_ref_loc (input_location,
> ...
> +	      else
> +		temp = parmse.expr;
> ...
> -	      if (!POINTER_TYPE_P (TREE_TYPE (parmse.expr)))
> -		tmp = gfc_build_addr_expr (NULL_TREE, tmp);
> +	      if (!POINTER_TYPE_P (TREE_TYPE (temp)))
> +		temp = gfc_build_addr_expr (NULL_TREE, temp);
> ...
> -				      logical_type_node, tmp,
> -				      fold_convert (TREE_TYPE (tmp),
> +				      logical_type_node, temp,
> +				      fold_convert (TREE_TYPE (temp)

I do not see any reason why 'tmp' is replaced by 'temp' in this
code. Also for doing patch archeology, it helps if there are no
changes unless it makes sense. Adding an -e- does not count ;-)

Hence, OK with that change.

  * * *

Regarding the change:
  gfc_conv_intrinsic_size (gfc_se * se, gfc_expr * expr)

It looks as if the pointer/check is done for
   size(dt%foo%bar)
for the 'bar' component' but shouldn't it also be
done for each part ref, if it is a pointer/allocatable?
(i.e. 'dt', 'foo' and 'bar'?

That's independent of the current patch.

Additionally, as there are a lot of special cases for
CLASS – I wonder whether there also needs to be a special
case for
   size(dt%foo%class)
?

In particular, the following does ICE for me:

module m
   type t
     class(*), pointer :: bar(:)
   end type
   type t2
     class(t), allocatable :: my(:)
   end type t2
contains
   function f (x, y) result(z)
     class(t) :: x(:)
     class(t) :: y(size(x(1)%bar))
     type(t)  :: z(size(x(1)%bar))
   end
   function g (x) result(z)
     class(t) :: x(:)
     type(t)  :: z(size(x(1)%bar))
   end
   subroutine s ()
     class(t2), allocatable :: a(:), b(:), c(:), d(:)
     class(t2), pointer     :: p(:)
     c(1)%my = f (a(1)%my, b(1)%my)
     d(1)%my = g (p(1)%my)
   end
end

  * * *
  

> P.S.: I couldn't find a Changelog entry that uses co-authors.  Is the
> version
> below correct?
...
> Co-authored-by: Paul Thomas  <pault@gcc.gnu.org>

I think you have two options: either the GIT way – as you did (although I think the
GIT way usually only has one and not two spaces before the email).

I did not see it in the commit logs, but it is used in the
testcases for the change-log generator, see: contrib/gcc-changelog/test_patches.txt

Alternative way is to specify the authors in the classical
ChangeLog style; latest real-world example is
https://gcc.gnu.org/g:d656bfda2d8316627d0bbb18b10954e6aaf3c88c
but you can also look at the contrib/gcc-changelog/test_patches.txt

Finally, you can also run the script at contrib/gcc-changelog/ yourself
as pre-commit check.
For instance, if you committed but did not yet push it:
  git show -1 | ./contrib/gcc-changelog/git_check_commit.py -p
to errors there, you can use 'git commit --amend' until you have
pushed that commit (then it is too late).

Tobias