On Tue, 27 Apr 2004, Carlo Florendo wrote:
> Igor Pechtchanski wrote:
>
> >On Mon, 26 Apr 2004, Carlo Florendo wrote:
> >
> >
> >>Larry Hall wrote:
> >>
> >>
> >>>At 11:28 PM 4/25/2004, you wrote:
> >>>
> >>>
> >>>>Hi,
> >>>>
> >>>>Now, upon running ./configure on blackbox, all was ok. When I started make,
> >>>>this is the error I got:
> >>>>
> >>>>Making all in src
> >>>>Window.cc:1396: error: `assert' undeclared (first use this function)
> >>>>Window.cc:3234: error: `assert' undeclared (first use this function)
> >>>>
> >>>>
> >>>Clearly the problem is that you're missing "#include <assert.h>". That's
> >>>likely the result of a configure problem but I didn't investigate to any
> >>>great extent so I might be wrong.
> >>>
> >>>
> >>Right! When I added "#include <assert.h>", blackbox compiled clearly.
> >>How come it didn't complain in the past cygwin? I compiled the same
> >>blackbox at a linux box (without my added "#include <assert.h>") and the
> >>thing built perfectly. How come the new cygwin behaves differently?
> >>
> >>Thanks!
> >>
> >>Best Regards,
> >>Carlo
> >>
> >>
> >
> >Well, as a WAG, assert.h could have been #included in some standard header
> >file before, and isn't now. This indicates buggy software, BTW: it
> >shouldn't rely on anything else including the needed functionality --
> >that's what the double include guards are for. The rule of thumb is:
> >"when in doubt, include it". You might want to submit a patch to the
> >blackbox maintainers.
> > Igor
>
> I installed the exact blackbox version as last time which is the latest
> official release. This latest official release has one file that calls
> assert() but does not #include it. I checked its include tree and, as
> far as I looked, have not found the #include <assert.h> anywhere on the
> tree.
Yes, because it expects <assert.h> to be included from one of the system
headers.
> Other files that call assert have the header included in them. The
> strangest thing is that the same version compiles under the current
> linux that I have (Redhat 9.0), the former cygwin, but *not* the latest
> cygwin.
That's because some Cygwin system headers got changed to not include
<assert.h> where they previously did.
> It compiles with the latest cygwin if I #include <assert.h> on
> the file in question.
>
> Does this mean that there is a problem with gcc? or configure? I'm
> confused now whether the problem resides in the packaging of blackbox,
> in the way ./configure runs on the old cygwin, or on the way ./configure
> runs on the new cygwin, or in Linux or even in gcc. Why doesn't gcc
> complain in the old cygwin and in Linux?
The problem is with blackbox. Apparently, some of the Linux system
headers[*] include <assert.h>, and so did some of the Cygwin ones. So
this particular file in blackbox relied on a needed header (<assert.h>) to
be inluded from elsewhere (another header). This is a bug. Cygwin's
headers got changed, and <assert.h> is no longer in the include chain, so
blackbox broke. The fix is to #include <assert.h> in the file that calls
assert(). It may also be possible to do this through some configure magic
if the project maintainers *really* want to avoid including <assert.h>
twice in the project code, but why bother?
> I could submit a patch to the blackbox maintainers but will have to tell
> them that the reason for it is so that it will compile with the latest
> cygwin. Or could it be that ./configure needs to be patched?
>
> Thanks a lot!
> Best Regards,
> Carlo
The reason for the patch is portability. Sure, it will compile on the
current Linux, but POSIX doesn't require any other header to include
<assert.h>, so blackbox should do it itself. As I said above, I don't
think you should bother with patching configure.
Igor
[*] If you want to find out which header includes <assert.h> on Linux,
simply preprocess the broken file on Linux using gcc -E and see where
"assert.h" got included from.
--
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