[Bug fortran/51828] New: libgfortran build warnings

[Bug fortran/51828] New: libgfortran build warnings

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51828

             Bug #: 51828
           Summary: libgfortran build warnings
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: burnus@gcc.gnu.org
                CC: jb@gcc.gnu.org, tkoenig@gcc.gnu.org


One currently gets on the 4.7 trunk the following libgfortran build warnings:

libgfortran/intrinsics/unpack_generic.c: In function 'unpack_internal':
libgfortran/intrinsics/unpack_generic.c:149:12: warning: 'rstride[0]' may be
used uninitialized in this function [-Wuninitialized]
libgfortran/intrinsics/unpack_generic.c:150:12: warning: 'fstride[0]' may be
used uninitialized in this function [-Wuninitialized]
libgfortran/intrinsics/unpack_generic.c:151:12: warning: 'mstride[0]' may be
used uninitialized in this function [-Wuninitialized]

[Bug fortran/51828] libgfortran build warnings

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51828

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-01-11
     Ever Confirmed|0                           |1

--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2012-01-11 20:58:30 UTC ---
Confirmed, I also see

../../../work/libgfortran/caf/libcaf.h:80:6: warning: no previous prototype for
'_gfortran_caf_critical' [-Wmissing-prototypes]
../../../work/libgfortran/caf/libcaf.h:81:6: warning: no previous prototype for
'_gfortran_caf_end_critical' [-Wmissing-prototypes]

[Bug fortran/51828] libgfortran build warnings

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51828

--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> 2012-01-11 21:05:01 UTC ---
(In reply to comment #1)
> I also see
> ../../../work/libgfortran/caf/libcaf.h:80:6: warning: no previous prototype for
> '_gfortran_caf_critical' [-Wmissing-prototypes]
> ../../../work/libgfortran/caf/libcaf.h:81:6: warning: no previous prototype for
> '_gfortran_caf_end_critical' [-Wmissing-prototypes]

Ignore that one - _gfortran_caf_critical / _gfortran_caf_end_critical is the
wrong approach for it. It should use internally type(lock_type) but that has
not yet been implemented.

[Bug fortran/51828] libgfortran build warnings

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51828

--- Comment #3 from Tobias Burnus <burnus at gcc dot gnu.org> 2012-01-11 22:32:56 UTC ---
(In reply to comment #0)
> libgfortran/intrinsics/unpack_generic.c: In function 'unpack_internal':

The warnings are bogus - assuming that "dim > 0" - as:

  if (ret->data == NULL)
      dim = GFC_DESCRIPTOR_RANK (mask);
      for (n = 0; n < dim; n++)
          rstride[n] = GFC_DESCRIPTOR_STRIDE_BYTES(ret, n);
  else
      dim = GFC_DESCRIPTOR_RANK (ret);
      for (n = 0; n < dim; n++)
          rstride[n] = GFC_DESCRIPTOR_STRIDE_BYTES(ret, n);

  rstride0 = rstride[0]; /* << may be used uninitialized in this function */

[Bug fortran/51828] libgfortran build warnings

[mikael at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51828

Mikael Morin <mikael at gcc dot gnu.org> changed:

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

--- Comment #4 from Mikael Morin <mikael at gcc dot gnu.org> 2012-02-27 21:17:39 UTC ---
(In reply to comment #3)
> (In reply to comment #0)
> > libgfortran/intrinsics/unpack_generic.c: In function 'unpack_internal':
> 
> The warnings are bogus - assuming that "dim > 0" - as:
> 
>   if (ret->data == NULL)
>       dim = GFC_DESCRIPTOR_RANK (mask);
>       for (n = 0; n < dim; n++)
>           rstride[n] = GFC_DESCRIPTOR_STRIDE_BYTES(ret, n);
>   else
>       dim = GFC_DESCRIPTOR_RANK (ret);
>       for (n = 0; n < dim; n++)
>           rstride[n] = GFC_DESCRIPTOR_STRIDE_BYTES(ret, n);
> 
>   rstride0 = rstride[0]; /* << may be used uninitialized in this function */

rstride0 = GFC_DESCRIPTOR_STRIDE_BYTES(ret, 0);  ?

assert (dim > 0); ?

otherwise -> WONTFIX : the compiler can't know that dim > 0.

[Bug libfortran/51828] libgfortran build warnings

[fxcoudert at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51828

--- Comment #5 from Francois-Xavier Coudert <fxcoudert at gcc dot gnu.org> ---
Author: fxcoudert
Date: Mon Nov 18 09:27:11 2013
New Revision: 204940

URL: http://gcc.gnu.org/viewcvs?rev=204940&root=gcc&view=rev
Log:
    PR libfortran/51828
    * intrinsics/unpack_generic.c (unpack_internal): Let the compiler
    know that dim > 0 to avoid warnings.

Modified:
    trunk/libgfortran/ChangeLog
    trunk/libgfortran/intrinsics/unpack_generic.c

[Bug libfortran/51828] libgfortran build warnings

[fxcoudert at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51828

Francois-Xavier Coudert <fxcoudert at gcc dot gnu.org> changed:

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

--- Comment #6 from Francois-Xavier Coudert <fxcoudert at gcc dot gnu.org> ---
Fixed on trunk.