Re: [PATCH] Fortran: rank checking with explicit-/assumed-size arrays and CLASS [PR58331]

[Harald Anlauf via Gcc-patches]

Hi Tobias,

Am 15.03.23 um 10:10 schrieb Tobias Burnus:

Hi Harald,

On 14.03.23 20:38, Harald Anlauf wrote:

The testcase covers only non-coarray cases, as playing with
coarray variants hit pre-exisiting issues in gfortran that
are very likely unrelated to the interface checks.

I concur (but would not rule out additional interface issues).


More testing seems to mostly uncover issues later on in trans*.cc,
e.g. when passing type to class.  I'll open a PR on this as a followup.


I consider this rather as post 13-release stuff.

In any case, the coarray issue can be fixed separately. And I think
post-GCC-13 makes sense.


Good.


Regtested on x86_64-pc-linux-gnu.  OK for mainline?

Thanks – LGTM!

+  formal_as = formal->ts.type == BT_CLASS ? CLASS_DATA (formal)->as
+   : formal->as;
+


(Jakub remarks for such code that some editor (emacs?), he does not use,
mis--auto-indent such a code - and proposes to add a parentheses
around the right-hand side of the assignment.)


Ah, adding parentheses helps!  I've reformatted this block accordingly.
Pushed as:

https://gcc.gnu.org/g:901edd99b44976b3c2b13a7d525d9e315540186a


* * *

I also wonder whether we need some run-time testcase. The interface
check now works and I also tend to write dg-do-compile testcases, but
given what can go wrong with all the array descriptor, class etc
handling, we may want to ensure it works at run time. – Thoughts?


If you comment out the lines with dg-error, the code compiles
and seems to run fine here.  I've even found cases where passing
array sections works correctly here and with current Intel it
does not ;-)

I'd prefer to postpone more elaborate run-time tests until we have
more non-ICEing related code.

Thanks,
Harald


(That's independent of the patch it and could be done as follow up, if
it deemed reasonable. The included testcase is surely compile-only as it
has dg-error checks.)

Tobias

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Re: [PATCH] Fortran: rank checking with explicit-/assumed-size arrays and CLASS [PR58331]

[Tobias Burnus]

Hi Harald,

On 14.03.23 20:38, Harald Anlauf wrote:

The testcase covers only non-coarray cases, as playing with
coarray variants hit pre-exisiting issues in gfortran that
are very likely unrelated to the interface checks.

I concur (but would not rule out additional interface issues).

I consider this rather as post 13-release stuff.

In any case, the coarray issue can be fixed separately. And I think
post-GCC-13 makes sense.

Regtested on x86_64-pc-linux-gnu.  OK for mainline?

Thanks – LGTM!

+  formal_as = formal->ts.type == BT_CLASS ? CLASS_DATA (formal)->as
+   : formal->as;
+


(Jakub remarks for such code that some editor (emacs?), he does not use,
mis--auto-indent such a code - and proposes to add a parentheses
around the right-hand side of the assignment.)

* * *

I also wonder whether we need some run-time testcase. The interface
check now works and I also tend to write dg-do-compile testcases, but
given what can go wrong with all the array descriptor, class etc
handling, we may want to ensure it works at run time. – Thoughts?

(That's independent of the patch it and could be done as follow up, if
it deemed reasonable. The included testcase is surely compile-only as it
has dg-error checks.)

Tobias

-
Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstraße 201, 80634 
München; Gesellschaft mit beschränkter Haftung; Geschäftsführer: Thomas 
Heurung, Frank Thürauf; Sitz der Gesellschaft: München; Registergericht 
München, HRB 106955

[PATCH] Fortran: rank checking with explicit-/assumed-size arrays and CLASS [PR58331]

[Harald Anlauf via Gcc-patches]

Dear all,

the attached patch, which is based on a draft by Tobias, fixes
an old rejects-valid issue with rank checking for CLASS arrays
by using the proper array spec of CLASS variables.

The testcase covers only non-coarray cases, as playing with
coarray variants hit pre-exisiting issues in gfortran that
are very likely unrelated to the interface checks.  I consider
this rather as post 13-release stuff.

Regtested on x86_64-pc-linux-gnu.  OK for mainline?

Thanks,
Harald

From 4453686ae4e70c14a0898c6687db912fa84ece9f Mon Sep 17 00:00:00 2001
From: Harald Anlauf 
Date: Tue, 14 Mar 2023 20:23:06 +0100
Subject: [PATCH] Fortran: rank checking with explicit-/assumed-size arrays and
 CLASS [PR58331]

gcc/fortran/ChangeLog:

	PR fortran/58331
	* interface.cc (compare_parameter): Adjust check of array dummy
	arguments to handle the case of CLASS variables.

gcc/testsuite/ChangeLog:

	PR fortran/58331
	* gfortran.dg/class_dummy_10.f90: New test.

Co-authored-by: Tobias Burnus 
---
 gcc/fortran/interface.cc | 27 +++---
 gcc/testsuite/gfortran.dg/class_dummy_10.f90 | 56 
 2 files changed, 76 insertions(+), 7 deletions(-)
 create mode 100644 gcc/testsuite/gfortran.dg/class_dummy_10.f90

diff --git a/gcc/fortran/interface.cc b/gcc/fortran/interface.cc
index dafe41753b7..1d0f8bb5915 100644
--- a/gcc/fortran/interface.cc
+++ b/gcc/fortran/interface.cc
@@ -2349,6 +2349,7 @@ compare_parameter (gfc_symbol *formal, gfc_expr *actual,
   char err[200];
   gfc_component *ppc;
   bool codimension = false;
+  gfc_array_spec *formal_as;

   /* If the formal arg has type BT_VOID, it's to one of the iso_c_binding
  procs c_f_pointer or c_f_procpointer, and we need to accept most
@@ -2540,6 +2541,9 @@ compare_parameter (gfc_symbol *formal, gfc_expr *actual,
   return false;
 }

+  formal_as = formal->ts.type == BT_CLASS ? CLASS_DATA (formal)->as
+	  : formal->as;
+
   if (codimension && formal->attr.allocatable)
 {
   gfc_ref *last = NULL;
@@ -2650,10 +2654,10 @@ compare_parameter (gfc_symbol *formal, gfc_expr *actual,
   if (symbol_rank (formal) == actual->rank || symbol_rank (formal) == -1)
 return true;

-  rank_check = where != NULL && !is_elemental && formal->as
-	   && (formal->as->type == AS_ASSUMED_SHAPE
-		   || formal->as->type == AS_DEFERRED)
-	   && actual->expr_type != EXPR_NULL;
+  rank_check = where != NULL && !is_elemental && formal_as
+&& (formal_as->type == AS_ASSUMED_SHAPE
+	|| formal_as->type == AS_DEFERRED)
+&& actual->expr_type != EXPR_NULL;

   /* Skip rank checks for NO_ARG_CHECK.  */
   if (formal->attr.ext_attr & (1 << EXT_ATTR_NO_ARG_CHECK))
@@ -2662,14 +2666,20 @@ compare_parameter (gfc_symbol *formal, gfc_expr *actual,
   /* Scalar & coindexed, see: F2008, Section 12.5.2.4.  */
   if (rank_check || ranks_must_agree
   || (formal->attr.pointer && actual->expr_type != EXPR_NULL)
-  || (actual->rank != 0 && !(is_elemental || formal->attr.dimension))
+  || (actual->rank != 0
+	  && !(is_elemental || formal->attr.dimension
+	   || (formal->ts.type == BT_CLASS
+		   && CLASS_DATA (formal)->attr.dimension)))
   || (actual->rank == 0
 	  && ((formal->ts.type == BT_CLASS
 	   && CLASS_DATA (formal)->as->type == AS_ASSUMED_SHAPE)
 	  || (formal->ts.type != BT_CLASS
 		   && formal->as->type == AS_ASSUMED_SHAPE))
 	  && actual->expr_type != EXPR_NULL)
-  || (actual->rank == 0 && formal->attr.dimension
+  || (actual->rank == 0
+	  && (formal->attr.dimension
+	  || (formal->ts.type == BT_CLASS
+		  && CLASS_DATA (formal)->attr.dimension))
 	  && gfc_is_coindexed (actual))
   /* Assumed-rank actual argument; F2018 C838.  */
   || actual->rank == -1)
@@ -2690,7 +2700,10 @@ compare_parameter (gfc_symbol *formal, gfc_expr *actual,
 	}
   return false;
 }
-  else if (actual->rank != 0 && (is_elemental || formal->attr.dimension))
+  else if (actual->rank != 0
+	   && (is_elemental || formal->attr.dimension
+	   || (formal->ts.type == BT_CLASS
+		   && CLASS_DATA (formal)->attr.dimension)))
 return true;

   /* At this point, we are considering a scalar passed to an array.   This
diff --git a/gcc/testsuite/gfortran.dg/class_dummy_10.f90 b/gcc/testsuite/gfortran.dg/class_dummy_10.f90
new file mode 100644
index 000..cee5d4d82b2
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/class_dummy_10.f90
@@ -0,0 +1,56 @@
+! { dg-do compile }
+! PR fortran/58331 - rank checking for CLASS dummy arguments
+
+module mymod
+  implicit none
+contains
+  subroutine mysub(a, n)
+integer,  intent(in) :: n
+class(*), intent(in) :: a(n)
+
+