[Qemacs-devel] Build breakage with gcc 5

[François Revol]

Hi,
It looks like defining __unused__ ourself is a really bad idea, the name
is actually reserved for implementation anyway, and gcc and X11 headers
use it... as alternative argument to __attribute__().

François.

$ gcc --version
gcc (Debian 5.2.1-16) 5.2.1 20150903
Copyright (C) 2015 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.

$ make
make -C libqhtml all
make[1]: Entering directory '/mnt/data/devel/qemacs/qemacs/libqhtml'
make[1]: Nothing to be done for 'all'.
make[1]: Leaving directory '/mnt/data/devel/qemacs/qemacs/libqhtml'
CC -c x11.c
In file included from /usr/include/X11/Xlib.h:47:0,
                 from x11.c:27:
/usr/include/X11/Xfuncproto.h:163:21: error: missing ')' after
"__has_attribute"
 #if __has_attribute(__unused__) \
                     ^
In file included from x11.c:22:0:
qe.h:68:44: error: missing binary operator before token "("
 #define __unused__           __attribute__((unused))
                                            ^
x11.c: In function ‘x11_handle_event’:
x11.c:1288:9: warning: variable ‘shift’ set but not used
[-Wunused-but-set-variable]
     int shift, ctrl, meta, len, key;
         ^
x11.c: In function ‘x11_bmp_unlock’:
x11.c:1791:9: warning: variable ‘ret’ set but not used
[-Wunused-but-set-variable]
     int ret;
         ^
Makefile:250: recipe for target '.objs/x11.o' failed
make: *** [.objs/x11.o] Error 1