[Bug c/23087] Misleading warning, "... differ in signedness"

["kst at mib dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #10 from kst at mib dot org  2008-03-30 21:49 -------
(In reply to comment #9)
> >I'd expect the warning to be muted in one of the calls, depending on
> -f{un}signed-char.
>
> No, char is a seperate type from signed char and unsigned char so they are
> always incompatiable when it comes to pointers to them.
>
> Closing as invalid.

Yes, they're incompatible -- but that's not what the warning says.

I'm now using gcc 4.1.3.  (Note that the warning doesn't appear without
"-pedantic".)  Here's the current behavior:
========================================
% cat tmp.c
void foo(void)
{
    signed char   *ps = "signed?";
    unsigned char *pu = "unsigned?";
}
% gcc --version
gcc (GCC) 4.1.3 20070929 (prerelease) (Ubuntu 4.1.2-16ubuntu2)
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

% gcc -c -pedantic tmp.c
tmp.c: In function `foo':
tmp.c:3: warning: pointer targets in initialization differ in signedness
tmp.c:4: warning: pointer targets in initialization differ in signedness
========================================

On my system plain char is signed, so for the initialization of ps,
the pointer targets *don't* differ in signedness.  A warning is
necessary; the warning that's currently printed is incorrect.

Here's what it should do:
========================================
[...]
% gcc -c -pedantic -c tmp.c
tmp.c: In function `foo':
tmp.c:3: warning: initialization from incompatible pointer type
tmp.c:4: warning: initialization from incompatible pointer type
========================================


-- 

kst at mib dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
         Resolution|INVALID                     |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23087