Description of problem:

Original problem can be found at https://bugzilla.gnome.org/show_bug.cgi?id=666081

This can be reduced to:

typedef int Foo;
typedef int Foo;

which on RHEL 6.2 gives

$ LC_ALL=C gcc -c typedef.c
typedef.c:2: error: redefinition of typedef 'Foo'
typedef.c:1: note: previous declaration of 'Foo' was here

The same program compiles with no errors nor warnings (-Wall -Wextra) on Fedora 16


https://bugzilla.gnome.org/show_bug.cgi?id=666081#c1 says:

"Dodji Seketeli [developer] 2011-12-13 12:59:18 UTC

Although the re-definition is unfortunate and should trigger a
warning, I think the code is valid, so this is a GCC issue.  I
believe this code is accepted in recent GCCs.  AIUI, the part of
the code in the C front-end in GCC that deals with this (in
trunk) is, in gcc/c-decl.c:

static bool
diagnose_mismatched_decls (tree newdecl, tree olddecl,
               tree *newtypep, tree *oldtypep)
{
[...]
      else if (pedantic && !flag_isoc1x)
    {
      pedwarn (input_location, OPT_pedantic,
           "redefinition of typedef %q+D", newdecl);
      locate_old_decl (olddecl);
    }
[...]
}"


Version-Release number of selected component (if applicable):

$ gcc --version
gcc (GCC) 4.4.6 20110731 (Red Hat 4.4.6-3)

$ rpm -q gcc
gcc-4.4.6-3.el6.x86_64