mingw and other gotchas in gcc 3.1
Mon Jun 24 09:32:00 GMT 2002
Monday, 24 June, 2002 Christopher Faylor firstname.lastname@example.org wrote:
CF> I'm finishing up on the release of gcc 3.1 and I have a few gotchas that
CF> I'd like to discuss:
CF> 1) I was going to take Red Hat's cue and release the new version of
CF> gcc as gcc3. However, this will require manual deinstallation of
CF> gcc (2.95.3-whatever) so this is probably a bad thing. Somehow, I
CF> just think that if we don't still make the older version of gcc
CF> available, there will be many "This used to build on gcc 2.95.3!!!"
CF> So, maybe I should rename the old version to gcc2 or release a version
CF> of 2.95.3 that names the binaries (i686-pc-cygwin-gcc2) differently.
CF> Any thoughts?
This should be ok. There're also libstdc++ header files but,
fortunately, dirs are named differently (g++-3 for 2.95.3 and g++-v3
for 3.*). Can we make sure that this will remain so?
Btw, libstdc++ in gcc 3.* is configured so that classes in std::
namespace are not visible unless one specify std:: via 'using' or
explicitly. I feel this can be the problem that will make most noise.
Cygwin setup is just one example of program affected. I have a patch
that should work with both 2.95.3 and 3.*, and can post it if you're
One more problem is min() and max() macros in windef.h. They conflict
with min and max functions from <std_limits.h>. I've patched
std_limits.h to #undef min and #undef max, but applications which do
#include <windows.h> // even if it's included non-directly
x = max (a, b);
would break. I haven't found better solution for this, other than
mention it in release notes, though.
CF> 2) I'm trying to remove most of the spec file magic that dealt with
CF> mingw and I think I've actually been pretty successful. However,
CF> my new scheme relies on changing the machine name from i686-pc-cygwin
CF> to i686-pc-mingw. That means that the new layout looks like this:
CF> total 0
CF> lrwxrwxrwx 1 cgf None 122 Jun 23 23:41 bin -> ../i686-pc-cygwin/bin
CF> lrwxrwxrwx 1 cgf None 125 Jun 23 23:42 include -> /usr/include/mingw
CF> lrwxrwxrwx 1 cgf None 113 Jun 23 23:42 lib -> /usr/lib/mingw
CF> total 0
CF> drwxr-xr-x 4 cgf None 0 Dec 25 2000 i686-pc-cygwin
CF> lrwxrwxrwx 1 cgf None 108 Jun 23 23:48 i686-pc-mingw -> i686-pc-cygwin
CF> Ideally, the include, lib stuff in /usr/i686-pc-mingw should not be a
CF> symbolic link but should, instead, be the actual directories that they
CF> reference. However, coordinating this will be tricky. I'm thinking that
CF> I should just add a postinstall script that will try to do the right thing
CF> if /usr/i686-pc-mingw doesn't have the right stuff. However, I'd like to
CF> confirm with Earnie/Danny that this new layout makes sense.
Do you think bin/ should contain cygwin->mingw cross-tools instead of
being link to i686-pc-cygwin?
CF> FWIW, I think this is the way I should have laid stuff out originally.
CF> 3) The above layout has a problem. It works ok generating mingw binaries but,
CF> with gcc-3.1, I've configured things using --enable-threads=posix. So, some
CF> binaries don't link successfully. That means that the libgcc.a library is
CF> inappropriate for mingw. So, the above directory layout can potentially
CF> become a little trickier since I'll need to build a libgcc.a (and libstdc++.a,
CF> I guess) for mingw. This seems like a lot of duplication of effort, though,
CF> so maybe I'll try to figure out some way to download the bits that I need
CF> from sourceforge or something. Or,...
CF> 4) Since mingw is becoming so logically separated from gcc, it is possible that
CF> it could become a separate package. So, if "someone" was willing to supply
CF> a gcc-mingw package, it would actually be helpful. I don't think I could
CF> stand the pain of making this optional, so the gcc package would rely on
CF> the gcc-mingw package rather than the other way around. This would allow
CF> updating libgcc.a and libstdc++.a without requiring a new release of gcc.
CF> Hmm. I wonder if I should break libstdc++.a out of the gcc package. Urgh.
CF> Any suckers (cough) want to contribute a separate package?
libstdc++ seems to be a problem, no matter what was passed to
--enable-threads. I agree that libstdc++ (and libgcc in case of
--enable-threads=posix) stuff for mingw should be packaged
separately. I build them by hand and tested cygwin setup with them,
but i still have no automatic script to produce such package.
CF> I've been toiling away at this for some time, so I'd appreciate any
CF> useful suggestions. My next hurdle is updating the gcc cygwin 3.1
CF> branch with the latest changes in the gcc 3.1 branch.
Have you created cygwin branch in gcc repository? I've seen your
question about it in email@example.com but somehow missed the final
Egor. mailto:firstname.lastname@example.org ICQ 5165414 FidoNet 2:5020/496.19
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