[Bug fortran/35831] Type-mismatch check missing for dummy procedure argument

[Bug fortran/35831] Type-mismatch check missing for dummy procedure argument

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35831

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |janus at gcc dot gnu.org

--- Comment #6 from janus at gcc dot gnu.org 2011-09-10 10:18:58 UTC ---
(In reply to comment #0)
> Fortran 2003's "12.4.1.3 Actual arguments associated with dummy procedure
> entities" has about this:
> 
> "If the interface of the dummy argument is explicit, the characteristics listed
> in 12.2 shall be the same for the associated actual argument and the
> corresponding dummy argument, except that a pure actual argument may be
> associated with a dummy argument that is not pure and an elemental intrinsic
> actual procedure may be associated with a dummy procedure (which is prohibited
> from being elemental)."


Note: The same restrictions are already listed in F95's chapter 12.4.1.2, as
well as F08's chapter 12.5.2.9. At first sight there are no differences between
the different versions of the standard in the quoted passage.

[Bug fortran/35831] [F95] Shape mismatch check missing for dummy procedure argument

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35831

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|Shape mismatch check        |[F95] Shape mismatch check
                   |missing for dummy procedure |missing for dummy procedure
                   |argument                    |argument

--- Comment #7 from janus at gcc dot gnu.org 2011-09-10 11:24:02 UTC ---
Some more F08 standard quotes:

"12.5.2.9 Actual arguments associated with dummy procedure entities
If the interface of a dummy procedure is explicit, its characteristics as a
procedure (12.3.1) shall be the same as those of its effective argument, ..."

"12.3.1 Characteristics of procedures
The characteristics of a procedure are the classification of the procedure as a
function or subroutine, whether it is pure, whether it is elemental, whether it
has the BIND attribute, the characteristics of its dummy arguments, ..."

"12.3.2.2 Characteristics of dummy data objects
The characteristics of a dummy data object are its type, its type parameters
(if any), its shape, ...
If a shape, size, or type parameter is assumed or deferred, it is a
characteristic."


Combining the three statements above, F08 clearly demands that the *shape* of
the argument should be the same (meaning that the bounds themselves may
differ).


"1.3.128 shape
array dimensionality of a data entity, represented as a rank-one array whose
size is the rank of the data entity and whose elements are the extents of the
data entity"


So I would conclude that:
 * comment #0 is invalid (as well as the original c.l.f. example)
 * comment #2 is valid (ifort's check seems to be too strict)

[Bug fortran/35831] [F95] Shape mismatch check missing for dummy procedure argument

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35831

--- Comment #8 from janus at gcc dot gnu.org 2011-09-10 11:26:50 UTC ---
(In reply to comment #7)
> "12.3.1 Characteristics of procedures
> The characteristics of a procedure are the classification of the procedure as a
> function or subroutine, whether it is pure, whether it is elemental, whether it
> has the BIND attribute, the characteristics of its dummy arguments, ..."
> 
> "12.3.2.2 Characteristics of dummy data objects
> The characteristics of a dummy data object are its type, its type parameters
> (if any), its shape, ...
> If a shape, size, or type parameter is assumed or deferred, it is a
> characteristic."
> 
> 
> Combining the three statements above, F08 clearly demands that the *shape* of
> the argument should be the same (meaning that the bounds themselves may
> differ).

Note that the same restrictions on dummy characteristics also apply to other
situations, like e.g. overriding type-bound procedures (cf. PR47978).

[Bug fortran/35831] [F95] Shape mismatch check missing for dummy procedure argument

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35831

--- Comment #9 from janus at gcc dot gnu.org 2011-09-11 10:06:03 UTC ---
(In reply to comment #7)
> Combining the three statements above, F08 clearly demands that the *shape* of
> the argument should be the same (meaning that the bounds themselves may
> differ).

However, there is one more sentence which seems to restrict this further:

"If a type parameter of an object or a bound of an array is not a constant
expression, the exact dependence on the entities in the expression is a
characteristic."

Here, the standard talks explicitly about 'bounds of an array' and not just the
'shape'.

Depending on how one reads this, it might mean two things:
 1) for non-constant bounds, the bounds themselves have to match, not only the
shape
 2) for non-constant bounds, the shape expression (i.e. "upper bound minus
lower bound") has to match, including the exact dependence on entities in the
expression

[Bug fortran/35831] [F95] Shape mismatch check missing for dummy procedure argument

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35831

--- Comment #10 from janus at gcc dot gnu.org 2011-09-11 20:12:30 UTC ---
Author: janus
Date: Sun Sep 11 20:12:24 2011
New Revision: 178767

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=178767
Log:
2011-09-11  Janus Weil  <janus@gcc.gnu.org>

    PR fortran/35831
    PR fortran/47978
    * interface.c (check_dummy_characteristics): New function to check the
    characteristics of dummy arguments.
    (gfc_compare_interfaces,gfc_check_typebound_override): Call it here.


2011-09-11  Janus Weil  <janus@gcc.gnu.org>

    PR fortran/35831
    PR fortran/47978
    * gfortran.dg/dynamic_dispatch_5.f03: Fix invalid test case.
    * gfortran.dg/proc_decl_26.f90: New.
    * gfortran.dg/typebound_override_2.f90: New.
    * gfortran.dg/typebound_proc_6.f03: Changed wording in error message.

Added:
    trunk/gcc/testsuite/gfortran.dg/proc_decl_26.f90
    trunk/gcc/testsuite/gfortran.dg/typebound_override_2.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/interface.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gfortran.dg/dynamic_dispatch_5.f03
    trunk/gcc/testsuite/gfortran.dg/typebound_proc_6.f03

[Bug fortran/35831] [F95] Shape mismatch check missing for dummy procedure argument

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35831

--- Comment #11 from janus at gcc dot gnu.org 2011-09-11 20:48:40 UTC ---
r178767 implements a check to reject the original c.l.f. test case as well as
the one in comment #0.

At this point I would tend to say that comment #2 is valid, but we also still
fail to reject things like "a(1:2)" vs "a(1:3)".

[Bug fortran/35831] [F95] Shape mismatch check missing for dummy procedure argument

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35831

--- Comment #12 from janus at gcc dot gnu.org 2011-09-29 16:41:13 UTC ---
Here's a link to a c.l.f. thread where I asked about this:

http://groups.google.com/group/comp.lang.fortran/browse_thread/thread/ae6a44043a3b1a95

[Bug fortran/35831] [F95] Shape mismatch check missing for dummy procedure argument

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35831

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
         AssignedTo|unassigned at gcc dot       |janus at gcc dot gnu.org
                   |gnu.org                     |

[Bug fortran/35831] [F95] Shape mismatch check missing for dummy procedure argument

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35831

--- Comment #13 from janus at gcc dot gnu.org 2011-10-04 18:37:22 UTC ---
Author: janus
Date: Tue Oct  4 18:37:13 2011
New Revision: 179520

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=179520
Log:
2011-10-04  Janus Weil  <janus@gcc.gnu.org>

    PR fortran/35831
    * interface.c (check_dummy_characteristics): Check the array shape.


2011-10-04  Janus Weil  <janus@gcc.gnu.org>

    PR fortran/35831
    * gfortran.dg/dummy_procedure_6.f90: New.

Added:
    trunk/gcc/testsuite/gfortran.dg/dummy_procedure_6.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/interface.c
    trunk/gcc/testsuite/ChangeLog

[Bug fortran/35831] [F95] Shape mismatch check missing for dummy procedure argument

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35831

--- Comment #14 from janus at gcc dot gnu.org 2011-10-04 18:52:37 UTC ---
r179520 should pretty much fix the shape checking for dummy arguments.

Related ToDos:
1) check shape of dummy function results (in 'gfc_compare_interfaces')
2) check shape of function results when overriding TBPs (in
'gfc_check_typebound_override')

I wonder if it would make sense to combine both tasks into a new function
'check_result_characteristics' or similar (together with the checks for
type/rank, string length, attributes, etc), cf. F08 chapter 12.3.3.

[Bug fortran/35831] [F95] Shape mismatch check missing for dummy procedure argument

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35831

--- Comment #15 from janus at gcc dot gnu.org 2011-10-05 20:06:33 UTC ---
(In reply to comment #14)
> Related ToDos:
> 1) check shape of dummy function results (in 'gfc_compare_interfaces')
> 2) check shape of function results when overriding TBPs (in
> 'gfc_check_typebound_override')

3) check string length of dummy function results (so far we only have a string
length check when overriding)


Test case (adapted from one of the IRs):



call caller(c1)

contains

  FUNCTION C1(N)
    CHARACTER(N) C1
  END FUNCTION C1

  SUBROUTINE CALLER(c2)
    INTERFACE
      FUNCTION C2(N)
    CHARACTER(2) C2
      END FUNCTION
    END INTERFACE
  end subroutine

end

[Bug fortran/35831] [F95] Shape mismatch check missing for dummy procedure argument

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35831

--- Comment #16 from janus at gcc dot gnu.org 2012-08-06 20:36:23 UTC ---
Author: janus
Date: Mon Aug  6 20:36:16 2012
New Revision: 190187

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=190187
Log:
2012-08-06  Janus Weil  <janus@gcc.gnu.org>

    PR fortran/35831
    * interface.c (check_result_characteristics): New function, which checks
    the characteristics of function results.
    (gfc_compare_interfaces,gfc_check_typebound_override): Call it.

2012-08-06  Janus Weil  <janus@gcc.gnu.org>

    PR fortran/35831
    * gfortran.dg/dummy_procedure_5.f90: Modified.
    * gfortran.dg/dummy_procedure_8.f90: New.
    * gfortran.dg/interface_26.f90: Modified.
    * gfortran.dg/proc_ptr_11.f90: Modified.
    * gfortran.dg/proc_ptr_15.f90: Modified.
    * gfortran.dg/proc_ptr_result_5.f90: Modified.
    * gfortran.dg/typebound_override_1.f90: Modified.
    * gfortran.dg/typebound_proc_6.f03: Modified.

Added:
    trunk/gcc/testsuite/gfortran.dg/dummy_procedure_8.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/interface.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gfortran.dg/dummy_procedure_5.f90
    trunk/gcc/testsuite/gfortran.dg/interface_26.f90
    trunk/gcc/testsuite/gfortran.dg/proc_ptr_11.f90
    trunk/gcc/testsuite/gfortran.dg/proc_ptr_15.f90
    trunk/gcc/testsuite/gfortran.dg/proc_ptr_result_5.f90
    trunk/gcc/testsuite/gfortran.dg/typebound_override_1.f90
    trunk/gcc/testsuite/gfortran.dg/typebound_proc_6.f03

[Bug fortran/35831] [F95] Shape mismatch check missing for dummy procedure argument

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35831

--- Comment #17 from janus at gcc dot gnu.org 2012-08-06 21:03:01 UTC ---
(In reply to comment #15)
> (In reply to comment #14)
> > Related ToDos:
> > 1) check shape of dummy function results (in 'gfc_compare_interfaces')
> > 2) check shape of function results when overriding TBPs (in
> > 'gfc_check_typebound_override')
> 
> 3) check string length of dummy function results (so far we only have a string
> length check when overriding)

r190187 does all of this (and basically a complete check of the result
characteristics).

Related TODOs:
 * improve gfc_dep_compare_expr to catch more cases (and/or enable the warnings
in check_result_characteristics and check_dummy_characteristics, marked by
FIXMEs)
 * check more attributes in check_dummy_characteristics (another FIXME)
 * Tobias' remarks at http://gcc.gnu.org/ml/fortran/2012-08/msg00034.html, e.g.
PR54189 and PR54190

[Bug fortran/35831] [F95] Shape mismatch check missing for dummy procedure argument

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35831

--- Comment #18 from janus at gcc dot gnu.org ---
Author: janus
Date: Tue Dec 10 21:41:43 2013
New Revision: 205873

URL: http://gcc.gnu.org/viewcvs?rev=205873&root=gcc&view=rev
Log:
2013-12-10  Janus Weil  <janus@gcc.gnu.org>

    PR fortran/35831
    * interface.c (check_dummy_characteristics): Add checks for several
    attributes.


2013-12-10  Janus Weil  <janus@gcc.gnu.org>

    PR fortran/35831
    * gfortran.dg/c_by_val_5.f90: Modified.
    * gfortran.dg/dummy_procedure_10.f90: New.

Added:
    trunk/gcc/testsuite/gfortran.dg/dummy_procedure_10.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/interface.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gfortran.dg/c_by_val_5.f90

[Bug fortran/35831] [F95] Shape mismatch check missing for dummy procedure argument

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35831

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #19 from janus at gcc dot gnu.org ---
(In reply to janus from comment #17)
> Related TODOs:
>  * improve gfc_dep_compare_expr to catch more cases (and/or enable the
> warnings in check_result_characteristics and check_dummy_characteristics,
> marked by FIXMEs)

This point is still open, but can be tracked e.g. in PR 37222.

>  * check more attributes in check_dummy_characteristics (another FIXME)

This has been implemented in r205873.

>  * Tobias' remarks at http://gcc.gnu.org/ml/fortran/2012-08/msg00034.html,
> e.g. PR54189 and PR54190

I think all of these remarks have been fixed by now (or at least sorted into
PRs).


All in all, I think this PR is ripe to get closed after more than five years
with (almost) everything fixed.