[Bug fortran/30438] Set but never used variable should raise warning

[dfranke at gcc dot gnu dot org]

------- Comment #5 from dfranke at gcc dot gnu dot org  2010-05-01 12:39 -------
With gcc version 4.6.0 20100501 (experimental) (GCC)

$ cat unused.c
int main() {
  int i;
  i = 42;
  return 0;
}

$ gcc-svn -Wall unused.c
unused.c: In function 'main':
unused.c:2:7: warning: variable 'i' set but not used
[-Wunused-but-set-variable]

Gfortran does not issue any warning with a similar fortran testcase.


Strangely, grepping the sources for use of the flag
'warn_unused_but_set_variable', I only find:

$ grep -r warn_unused_but_set_variable *
ChangeLog:      * toplev.c (warn_unused_but_set_variable): Default to
warn_unused.
common.opt:Common Var(warn_unused_but_set_variable) Init(-1) Warning
toplev.c:  if (warn_unused_but_set_variable == -1)
toplev.c:    warn_unused_but_set_variable = warn_unused;

which is slightly less than expected - where/how is this flag used?!


-- 

dfranke at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dfranke at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30438