[Bug fortran/31461] warn about entities in USE, ONLY statement not later used

[Bug fortran/31461] warn about entities in USE, ONLY statement not later used

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31461

Tobias Burnus <burnus at gcc dot gnu.org> changed:

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

--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-08-17 13:27:05 UTC ---
That's simpler than I though. Draft patch:

--- a/gcc/fortran/trans-decl.c
+++ b/gcc/fortran/trans-decl.c
@@ -4453,6 +4453,9 @@ generate_local_decl (gfc_symbol * sym)
                    || sym->attr.in_namelist))
        gfc_warning ("Unused variable '%s' declared at %L", sym->name,
                     &sym->declared_at);
+      else if (warn_unused_variable && sym->attr.use_only)
+       gfc_warning ("Unused module variable '%s' which has been explicitly "
+                    "imported at %L", sym->name, &sym->declared_at);

       /* For variable length CHARACTER parameters, the PARM_DECL already
         references the length variable, so force gfc_get_symbol_decl

[Bug fortran/31461] warn about entities in USE, ONLY statement not later used

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31461

--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-08-17 16:31:20 UTC ---
Author: burnus
Date: Wed Aug 17 16:31:10 2011
New Revision: 177833

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=177833
Log:
2011-08-17  Tobias Burnus  <burnus@net-b.de>

        PR fortran/31461
        * trans-decl.c (generate_local_decl): Warn about
        unused explicitly imported module variables/parameters.

2011-08-17  Tobias Burnus  <burnus@net-b.de>

        PR fortran/31461
        * gfortran.dg/warn_unused_var_2.f90: New.
        * gfortran.dg/warn_unused_var_3.f90: New.


Added:
    trunk/gcc/testsuite/gfortran.dg/warn_unused_var_2.f90
    trunk/gcc/testsuite/gfortran.dg/warn_unused_var_3.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/trans-decl.c
    trunk/gcc/testsuite/ChangeLog

[Bug fortran/31461] warn about entities in USE, ONLY statement not later used

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31461

Tobias Burnus <burnus at gcc dot gnu.org> changed:

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

--- Comment #3 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-08-17 16:32:30 UTC ---
FIXED on the trunk (GCC 4.7).

Thanks for the suggestion - and sorry for taking 4 years to implement it.

[Bug fortran/31461] New: warn about entities in USE, ONLY statement not later used

[vivekrao4 at yahoo dot com]

I request that gfortran optionally warn about entities appearing in a USE, ONLY
statement that are not later referenced in the program block where the USE
appears. For example, for the code

module util_mod
integer :: i,j
end module util_mod

program main
use util_mod, only: i,j
j = 1
print*,"j=",j
end program main

g95 -Wall -Wextra -c 

says

In file xunused_simple.f90:6

use util_mod, only: i,j
                      1
Warning (136): Module variable 'i' at (1) is never used
In file xunused_simple.f90:6

use util_mod, only: i,j
                      1
Warning (109): ONLY variable 'i' USE-d at (1) is never used or set


-- 
           Summary: warn about entities in USE, ONLY statement not later
                    used
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: vivekrao4 at yahoo dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31461

[Bug fortran/31461] warn about entities in USE, ONLY statement not later used

[fxcoudert at gcc dot gnu dot org]

-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2007-04-18 07:08:30
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31461