[Bug c++/43454] New: warning with -Wall despite __attribute__ ((__unused__))

["bruno at clisp dot org" <gcc-bugzilla at gcc dot gnu dot org>]

The attached program gives a warning about 'check_moo' being unused,
despite the variable being declared with __attribute__ ((__unused__)).

================================= bug.cc ==================================
extern "C" int c_foo (void);
namespace gnulib { static int (*foo) (void) = ::c_foo; }
static int (* __attribute__ ((__unused__)) check_foo) (void) = gnulib::foo;

extern "C" int c_moo (void);
namespace gnulib { static int (*const moo) (void) = ::c_moo; }
static int (* __attribute__ ((__unused__)) check_moo) (void) = gnulib::moo;
===========================================================================
$ g++ -Wall -S bug.cc
bug.cc:7: warning: 'check_moo' defined but not used

The warning is present in all g++ version of 3.x and 4.x that I tested,
except in g++ 4.0.2. I.e. "Known to work" = 4.0.2, "Known to fail" =
4.0.4, 4.1.2, 4.2.4, 4.3.4, 4.4.3.

The only difference between check_foo (which does not elicit a warning)
and check_moo is the 'const'ness of the initializer.


-- 
           Summary: warning with -Wall despite __attribute__ ((__unused__))
           Product: gcc
           Version: 4.4.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: bruno at clisp dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43454