[Bug fortran/44055] New: Warn (-Wconversion*) when converting single to double precision

[Bug fortran/44055] New: Warn (-Wconversion*) when converting single to double precision

[burnus at gcc dot gnu dot org]

With the patch http://gcc.gnu.org/ml/fortran/2010-05/msg00067.html (for PR
27866, PR 35003, PR 42809) the number of conversion warnings has drastically
been cut down by drastically cutting down the number of unintended warnings.
However, it no longer warns for

  real(8) :: sqrt2
  sqrt2 = sqrt(2.0)

where one has the precision loss due to forgetting to use "2.0_8" / "2.0d0"
instead of "2.0"; cf. PR 27866.

The idea is to add another -W* flag which finds those problems. Finding the
corresponding -W* flag will be made easier using PR 44054.

I think both the -Wconversion and the new -Wconversion-* warning should be
enabled with -Wall.


-- 
           Summary: Warn (-Wconversion*) when converting single to double
                    precision
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: burnus at gcc dot gnu dot org
 BugsThisDependsOn: 44054


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44055

[Bug fortran/44055] Warn (-Wconversion*) when converting single to double precision

[dfranke at gcc dot gnu dot org]

------- Comment #1 from dfranke at gcc dot gnu dot org  2010-05-10 17:02 -------
I think -Wconversion-extra would be a good choice.
We could enable -Wconversion with -Wall and -Wconversion-extra with -Wextra?!


-- 

dfranke at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dfranke at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2010-05-10 17:02:05
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44055

[Bug fortran/44055] Warn (-Wconversion*) when converting single to double precision

[dfranke at gcc dot gnu dot org]

------- Comment #2 from dfranke at gcc dot gnu dot org  2010-05-10 22:12 -------
Removed dependence on PR44054, handling those options is not (strictly)
required here. Nice yes,required, no ;)

Assigning to myself, patch is regtesting.


-- 

dfranke at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|44054                       |
         AssignedTo|unassigned at gcc dot gnu   |dfranke at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2010-05-10 17:02:05         |2010-05-10 22:12:07
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44055

[Bug fortran/44055] Warn (-Wconversion*) when converting single to double precision

[dfranke at gcc dot gnu dot org]

------- Comment #3 from dfranke at gcc dot gnu dot org  2010-05-13 12:31 -------
Suggested patch:
    http://gcc.gnu.org/ml/fortran/2010-05/msg00109.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44055

[Bug fortran/44055] Warn (-Wconversion*) when converting single to double precision

[dfranke at gcc dot gnu dot org]

------- Comment #4 from dfranke at gcc dot gnu dot org  2010-05-19 16:36 -------
Subject: Bug 44055

Author: dfranke
Date: Wed May 19 16:35:34 2010
New Revision: 159586

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=159586
Log:
gcc/fortran/:
2010-05-19  Daniel Franke  <franke.daniel@gmail.com>

        PR fortran/44055
        * lang.opt (Wconversion-extra): New option.
        * gfortran.h (gfc_option_t): Add warn_conversion_extra.
        * options.c (gfc_init_options): Disable -Wconversion-extra by default.
        (set_Wall): Enable -Wconversion.
        (gfc_handle_option): Set warn_conversion_extra.
        * intrinsic.c (gfc_convert_type_warn): Ignore kind conditions
        introduced for -Wconversion if -Wconversion-extra is present.
        * invoke.texi: Add -Wconversion to -Wall; document new behaviour of
        -Wconversion; document -Wconversion-extra.

gcc/testsuite/:
2010-05-19  Daniel Franke  <franke.daniel@gmail.com>

        PR fortran/44055
        * gfortran.dg/c_sizeof_2.f90: Add -Wno-conversion to dg-options;
        Fixed scope of C_SIZEOF.
        * gfortran.dg/warn_conversion_2.f90: New.


Added:
    trunk/gcc/testsuite/gfortran.dg/warn_conversion_2.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/gfortran.h
    trunk/gcc/fortran/intrinsic.c
    trunk/gcc/fortran/invoke.texi
    trunk/gcc/fortran/lang.opt
    trunk/gcc/fortran/options.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gfortran.dg/c_sizeof_2.f90


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44055

[Bug fortran/44055] Warn (-Wconversion*) when converting single to double precision

[dfranke at gcc dot gnu dot org]

------- Comment #5 from dfranke at gcc dot gnu dot org  2010-05-19 17:34 -------
Fixed in trunk. Closing.


-- 

dfranke at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.6.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44055