[Bug fortran/25071] dummy argument larger than actual argument

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

Dominique d'Humieres  changed:

   What|Removed |Added

 Status|NEW |RESOLVED
 Resolution|--- |FIXED

--- Comment #28 from Dominique d'Humieres  ---
Closing.

[Bug fortran/25071] dummy argument larger than actual argument

[dominiq at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

--- Comment #27 from dominiq at gcc dot gnu.org ---
Author: dominiq
Date: Fri Sep 29 13:19:21 2017
New Revision: 253287

URL: https://gcc.gnu.org/viewcvs?rev=253287=gcc=rev
Log:
2017-09-29  Dominique d'Humieres  

PR fortran/25071
* gfortran.dg/argument_checking_3.f90: Change warnings to errors.
* gfortran.dg/argument_checking_4.f90: Likewise.
* gfortran.dg/argument_checking_5.f90: Likewise.
* gfortran.dg/argument_checking_6.f90: Likewise.
* gfortran.dg/argument_checking_10.f90: Likewise.
* gfortran.dg/argument_checking_13.f90: Likewise.
* gfortran.dg/argument_checking_15.f90: Likewise.
* gfortran.dg/argument_checking_18.f90: Likewise.
* gfortran.dg/gomp/udr8.f90: Likewise.
* gfortran.dg/warn_argument_mismatch_1.f90: Add -std=legacy to
the dg-options.


Modified:
trunk/gcc/testsuite/ChangeLog
trunk/gcc/testsuite/gfortran.dg/argument_checking_10.f90
trunk/gcc/testsuite/gfortran.dg/argument_checking_13.f90
trunk/gcc/testsuite/gfortran.dg/argument_checking_15.f90
trunk/gcc/testsuite/gfortran.dg/argument_checking_18.f90
trunk/gcc/testsuite/gfortran.dg/argument_checking_3.f90
trunk/gcc/testsuite/gfortran.dg/argument_checking_4.f90
trunk/gcc/testsuite/gfortran.dg/argument_checking_5.f90
trunk/gcc/testsuite/gfortran.dg/argument_checking_6.f90
trunk/gcc/testsuite/gfortran.dg/gomp/udr8.f90
trunk/gcc/testsuite/gfortran.dg/warn_argument_mismatch_1.f90

[Bug fortran/25071] dummy argument larger than actual argument

[dominiq at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

--- Comment #26 from dominiq at gcc dot gnu.org ---
Author: dominiq
Date: Fri Sep 29 13:15:26 2017
New Revision: 253286

URL: https://gcc.gnu.org/viewcvs?rev=253286=gcc=rev
Log:
2017-09-29  Dominique d'Humieres  

PR fortran/25071
* interface.c (compare_actual_formal): Change warnings to errors
when "Actual argument contains too few elements for dummy
argument", unless -std=legacy is used.


Modified:
trunk/gcc/fortran/ChangeLog
trunk/gcc/fortran/interface.c

[Bug fortran/25071] dummy argument larger than actual argument

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

--- Comment #25 from Dominique d'Humieres  ---
Patch at https://gcc.gnu.org/ml/fortran/2017-09/msg00126.html.

[Bug fortran/25071] dummy argument larger than actual argument

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

Dominique d'Humieres  changed:

   What|Removed |Added

   Assignee|unassigned at gcc dot gnu.org  |dominiq at lps dot 
ens.fr

--- Comment #24 from Dominique d'Humieres  ---
Taking.

[Bug fortran/25071] dummy argument larger than actual argument

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

--- Comment #23 from Dominique d'Humieres  ---
> On the current trunk, the patch produces one failure:
>
> FAIL: gfortran.dg/warn_argument_mismatch_1.f90   -O  (test for excess errors)
>
> Another problem is that it removes the warning for -std=legacy.
>
> Do with it what you will ...

Thanks for the pointers, they will save me some time. I think I can handle the
problems myself.

[Bug fortran/25071] dummy argument larger than actual argument

[janus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

janus at gcc dot gnu.org changed:

   What|Removed |Added

   Assignee|janus at gcc dot gnu.org   |unassigned at gcc dot 
gnu.org

--- Comment #22 from janus at gcc dot gnu.org ---
On the current trunk, the patch produces one failure:

FAIL: gfortran.dg/warn_argument_mismatch_1.f90   -O  (test for excess errors)

Another problem is that it removes the warning for -std=legacy.

Do with it what you will ...

[Bug fortran/25071] dummy argument larger than actual argument

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

--- Comment #21 from Dominique d'Humieres  ---
> Please do if you can, after testing on trunk.

I can do it if Janus unassign himself.

[Bug fortran/25071] dummy argument larger than actual argument

[jvdelisle at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

Jerry DeLisle  changed:

   What|Removed |Added

 CC||jvdelisle at gcc dot gnu.org

--- Comment #20 from Jerry DeLisle  ---
(In reply to Dominique d'Humieres from comment #19)
> > Any opinions on this?
> 
> So far 2 for, 0 against. May be the patch can be committed?

Please do if you can, after testing on trunk.

[Bug fortran/25071] dummy argument larger than actual argument

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

--- Comment #19 from Dominique d'Humieres  ---
> Any opinions on this?

So far 2 for, 0 against. May be the patch can be committed?

[Bug fortran/25071] dummy argument larger than actual argument

[jb at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

--- Comment #18 from Janne Blomqvist  ---
(In reply to janus from comment #16)
> Any opinions on this?

+1

[Bug fortran/25071] dummy argument larger than actual argument

[janus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

janus at gcc dot gnu.org changed:

   What|Removed |Added

   Assignee|unassigned at gcc dot gnu.org  |janus at gcc dot gnu.org

--- Comment #16 from janus at gcc dot gnu.org ---
(In reply to Dominique d'Humieres from comment #15)
> The errors introduced at r124411 have been changed to warnings by Tobias
> Burnus at r126271

.. but only for the CHARACTER case. For non-character arrays there were never
any errors, and a warning has been added only in the second commit you mention.


> > Legacy code like the one in comment #11 should be allowed with -std=legacy
> > only (if at all).
> 
> If there is an agreement about that, this is something that I can handle.

I'm not sure if there will be any agreement about it, but in any case here is a
patch proposal:


Index: gcc/fortran/interface.c
===
--- gcc/fortran/interface.c (Revision 233007)
+++ gcc/fortran/interface.c (Arbeitskopie)
@@ -2787,10 +2787,10 @@
 f->sym->name, actual_size, formal_size,
 >expr->where);
   else if (where)
-   gfc_warning (0, "Actual argument contains too few "
-"elements for dummy argument %qs (%lu/%lu) at %L",
-f->sym->name, actual_size, formal_size,
->expr->where);
+   gfc_notify_std (GFC_STD_LEGACY, "Actual argument contains too few "
+   "elements for dummy argument %qs (%lu/%lu) at %L",
+   f->sym->name, actual_size, formal_size,
+   >expr->where);
  return  0;
}


On comment 0 this gives a hard error with -std=f95/f2003/f2008, a warning (as
before) with -std=gnu and no diagnostic at all with -std=legacy.

For comment 11 the behavior is almost unchanged, giving a warning for all -std
levels except legacy.

The patch does not trigger any failures in the testsuite, which is certainly a
good sign. It might still break some legacy codes, but they can just use
-std=legacy (which they probably already do). Everyone else will rather benefit
from the stricter diagnostics, I guess. It can catch some rather bad errors.

Any opinions on this?

[Bug fortran/25071] dummy argument larger than actual argument

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

--- Comment #17 from Dominique d'Humieres  ---
> Any opinions on this?

It's fine for me.

[Bug fortran/25071] dummy argument larger than actual argument

[janus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

--- Comment #14 from janus at gcc dot gnu.org ---
Legacy code like the one in comment #11 should be allowed with -std=legacy only
(if at all).

[Bug fortran/25071] dummy argument larger than actual argument

[janus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

--- Comment #13 from janus at gcc dot gnu.org ---
(In reply to Dominique d'Humieres from comment #12)
> AFAICT everything is fixed, but for
> comment 7 preferring an error instead of the warning. Since warnings can be
> turned into errors with -Werror, I don't think this PR should stay opened.

I disagree: Code like comment #0 should give an error by default. That's also
what other compilers do (e.g. ifort & sunf95) and I don't see how this can be a
useful 'extension'. It is certainly problematic code.

[Bug fortran/25071] dummy argument larger than actual argument

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

Dominique d'Humieres  changed:

   What|Removed |Added

 Status|REOPENED|NEW

--- Comment #15 from Dominique d'Humieres  ---
> > AFAICT everything is fixed, but for
> > comment 7 preferring an error instead of the warning. Since warnings can be
> > turned into errors with -Werror, I don't think this PR should stay opened.
>
> I disagree: Code like comment #0 should give an error by default.
> That's also what other compilers do (e.g. ifort & sunf95) and I don't see
> how this can be a useful 'extension'. It is certainly problematic code.

The errors introduced at r124411 have been changed to warnings by Tobias Burnus
at r126271, see the rationale at
https://gcc.gnu.org/ml/fortran/2007-06/msg00519.html.

> Legacy code like the one in comment #11 should be allowed with -std=legacy
> only (if at all).

If there is an agreement about that, this is something that I can handle.

IMO this PR should be closed as FIXED and a new one should be opened for the
warning->error conversion.

[Bug fortran/25071] dummy argument larger than actual argument

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

--- Comment #12 from Dominique d'Humieres  ---
No activity for more than four years. AFAICT everything is fixed, but for
comment 7 preferring an error instead of the warning. Since warnings can be
turned into errors with -Werror, I don't think this PR should stay opened.

[Bug fortran/25071] dummy argument larger than actual argument

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

--- Comment #10 from Tobias Burnus burnus at gcc dot gnu.org 2011-01-27 
09:16:47 UTC ---
(In reply to comment #7)
 Sorry for being 'a bit' late with comments, but IMHO this should be an error
 and not just a warning, because

 2) Other compilers reject it (so we can't argue that we must support this
 common extension)

Well, ifort and pathscale compile w/o warning and g95 with just a warning the
example at:  gfortran.fortran-torture/execute/st_function.f90

Thus, for compare_actual_formal I would make a distinction between:

  /* Special case for character arguments.  For allocatable, pointer
 and assumed-shape dummies, the string length needs to match
 exactly.  */

where I agree that at least for pointer and allocatable an error should be
printed - but probably also for assumed-shape dummies.

And to
  if (actual_size != 0
 actual_size  formal_size
 a-expr-ts.type != BT_PROCEDURE)

which can be less problematic and where a warning might be sufficient.

[Bug fortran/25071] dummy argument larger than actual argument

[Joost.VandeVondele at pci dot uzh.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

--- Comment #11 from Joost VandeVondele Joost.VandeVondele at pci dot uzh.ch 
2011-01-27 13:22:49 UTC ---
I actually vaguely recall why this should be a warning, and not be checked for
at runtime. This is for legacy codes using real :: a(1) instead of real ::
a(*). Something like

SUBROUTINE S1(a)
  INTEGER :: a(10)
  a(10)=0
END SUBROUTINE

SUBROUTINE S2(a)
  INTEGER :: a(1)
  CALL S1(a)
END SUBROUTINE

INTEGER :: a(10)
CALL S2(a)
END

'works just fine'...

[Bug fortran/25071] dummy argument larger than actual argument

[jb at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

Janne Blomqvist jb at gcc dot gnu.org changed:

   What|Removed |Added

 Status|RESOLVED|REOPENED
 CC||jb at gcc dot gnu.org
 Resolution|FIXED   |

--- Comment #7 from Janne Blomqvist jb at gcc dot gnu.org 2011-01-25 12:01:17 
UTC ---
Reopening..

(In reply to comment #6)
 I believe this is fixed by PR30940.
 
 The first example gives:
 Warnung: Actual argument contains too few elements for dummy argument 'i' 
 (4/6)
 at (1)
 
 The second example:
 Warnung: Character length of actual argument shorter than of dummy argument 
 'y'
 (10/20) at (1)
 
 It currently gives only warnings since I failed to get any comments when an
 error and when only a warning should be given.

Sorry for being 'a bit' late with comments, but IMHO this should be an error
and not just a warning, because

1) The standard says so

2) Other compilers reject it (so we can't argue that we must support this
common extension)

3) Not rejecting it makes it really easy to corrupt memory. Consider

program x
  character(len=10) :: a, b, c
  a = 1234567890
  b = a
  c = a
  call xx2(b)
  print *, '::', a, '::', b, '::', c, '::'
contains
  subroutine xx2(name)
character(len=20), intent(inout) :: name
name = 'hi'
  end subroutine xx2
end program

This prints (gfortran 4.4, x86_64 Linux):

$ ./chardummy2
 ::567890::hi::1234567890::

That is, blanking out the remaining 18 characters at the end of the character b
passed to xx2 overwrites part of the character a (why are only 4 characters
overwritten and not all 10? because they are allocated 4/8/16? byte aligned on
the stack). Note that neither bounds checking nor valgrind detects this error.

 
 Missing is the check for array element designators: PR32616.

I haven't looked, but maybe PR30940 and PR32616 would need to be fixed as well?

[Bug fortran/25071] dummy argument larger than actual argument

[Joost.VandeVondele at pci dot uzh.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

--- Comment #8 from Joost VandeVondele Joost.VandeVondele at pci dot uzh.ch 
2011-01-25 12:12:59 UTC ---
(In reply to comment #7)
 Reopening..

actually, I think this is a kind of error that should be caught at run-time
with -fcheck=arguments (not to say bounds). I guess that's not so easy to
implement, as it seem to imply that additional hidden subroutine arguments need
to be passed around.

[Bug fortran/25071] dummy argument larger than actual argument

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

--- Comment #9 from Tobias Burnus burnus at gcc dot gnu.org 2011-01-25 
12:41:11 UTC ---
(In reply to comment #8)
 actually, I think this is a kind of error that should be caught at run-time
 with -fcheck=arguments (not to say bounds). I guess that's not so easy to
 implement, as it seem to imply that additional hidden subroutine arguments 
 need
 to be passed around.

Well, that assumes that one compiles all files with the checking option. I like
the idea better to have a global (static, SAVE) derived-type (struct) variable
which contains the arguments and a function pointer. If loc(current function)
== loc(function pointer) then the argument checking is done - else it is for a
different function and no checking is done.

[Bug fortran/25071] dummy argument larger than actual argument

[burnus at gcc dot gnu dot org]

--- Comment #6 from burnus at gcc dot gnu dot org  2007-07-24 09:42 ---
I believe this is fixed by PR30940.

The first example gives:
Warnung: Actual argument contains too few elements for dummy argument 'i' (4/6)
at (1)

The second example:
Warnung: Character length of actual argument shorter than of dummy argument 'y'
(10/20) at (1)

It currently gives only warnings since I failed to get any comments when an
error and when only a warning should be given.

Missing is the check for array element designators: PR32616.


-- 

burnus at gcc dot gnu dot org changed:

   What|Removed |Added

 CC||burnus at gcc dot gnu dot
   ||org
 Status|NEW |RESOLVED
 Resolution||FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

[Bug fortran/25071] dummy argument larger than actual argument

[burnus at gcc dot gnu dot org]

--- Comment #4 from burnus at gcc dot gnu dot org  2007-05-04 08:54 ---
Subject: Bug 25071

Author: burnus
Date: Fri May  4 07:54:06 2007
New Revision: 124411

URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=124411
Log:
2007-05-04  Tobias Burnus  [EMAIL PROTECTED]

PR fortran/25071
* interface.c (compare_actual_formal): Check character length.

2007-05-04  Tobias Burnus  [EMAIL PROTECTED]

PR fortran/25071
* gfortran.dg/char_length_3.f90: New test.
* gfortran.dg/char_result_2.f90: Fix test.


Added:
trunk/gcc/testsuite/gfortran.dg/char_length_3.f90
Modified:
trunk/gcc/fortran/ChangeLog
trunk/gcc/fortran/interface.c
trunk/gcc/testsuite/ChangeLog
trunk/gcc/testsuite/gfortran.dg/char_result_2.f90


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

[Bug fortran/25071] dummy argument larger than actual argument

[burnus at gcc dot gnu dot org]

--- Comment #5 from burnus at gcc dot gnu dot org  2007-05-04 08:55 ---
Note: Only the string length problem is fixed; the array storage extend still
needs to be fixed.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

[Bug fortran/25071] dummy argument larger than actual argument

[patchapp at dberlin dot org]

--- Comment #3 from patchapp at dberlin dot org  2007-05-03 20:50 ---
Subject: Bug number PR25071

A patch for this bug has been added to the patch tracker.
The mailing list url for the patch is
http://gcc.gnu.org/ml/gcc-patches/2007-05/msg00186.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

[Bug fortran/25071] dummy argument larger than actual argument

[burnus at gcc dot gnu dot org]

--- Comment #2 from burnus at gcc dot gnu dot org  2007-04-19 16:16 ---
Analogously for character lengths:

program test
   character(len=10) :: x
   call foo(x)
   write(*,*) 'X=',x
contains
subroutine foo(y)
   character(len=20) :: y
   y = 'hello world'
end subroutine
   end

Taken from: http://ftp.aset.psu.edu/pub/ger/fortran/test/ test17.f90 (slightly
modified).

g95: Actual character argument at (1) is shorter in length than the formal
argument

NAG f95: Character length too short for arg Y (no. 1) of FOO

ifort: Character length argument mismatch. [X]


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071

[Bug fortran/25071] dummy argument larger than actual argument

[fxcoudert at gcc dot gnu dot org]

--- Comment #1 from fxcoudert at gcc dot gnu dot org  2005-11-26 19:48 
---
## g95 ##
In file foo.f90:2

CALL TST(I)
  1
Error: Array argument at (1) is smaller than the dummy size
## Intel ##
fortcom: Error: foo.f90, line 2: The storage extent of the dummy argument
exceeds that of the actual argument.   [I]
CALL TST(I)
-^
fortcom: Info: foo.f90, line 4: This variable has not been used.   [I]
 SUBROUTINE TST(I)
^
compilation aborted for foo.f90 (code 1)
## Portland ##
## Sun ##

CALL TST(I)
 ^
foo.f90, Line = 2, Column = 10: ERROR: The overall size of the dummy argument
array is greater than the size of this actual argument.


-- 

fxcoudert at gcc dot gnu dot org changed:

   What|Removed |Added

 Status|UNCONFIRMED |NEW
 Ever Confirmed|0   |1
   Keywords||accepts-invalid
   Last reconfirmed|-00-00 00:00:00 |2005-11-26 19:48:38
   date||
Summary|better diagnostic needed|dummy argument larger than
   ||actual argument


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25071