Gilles Chanteperdrix wrote: > Jan Kiszka wrote: > > I just analysed this further: the problem disappears when I manually > > remove any "-I<path-to-kernel-includes>" from the makefiles. Seems to be > > the well-known user space include issue again... ;) > > I tried to compile every kernel arch/i386 has a patch for with gcc 2.95, > 3.3 and 3.4, and I saw no issue with inclusions of kernel headers > from user-space. At all.
I think you were lucky. As far as I remember, it is generally no good idea to include kernel header for userspace compilation as long as you do not _exactly_ know (or test) what they bring with them. Some structures or defines locate in different headers under /usr/include compared to some kernel tree. So, if you are not lucky, you drag those definitions in twice - see below. > > So, there is definitely something you are doing differently from me. > If this issue is different from the '-m32' flag issue, could you please > fill a bug report, and this time, attach the exact procedure you are > following to compile (whether in-tree, or out-of-tree, whether using > configure or Kconfig, everything that would allow someone to ), the > .config and .xeno_config files you used, in order for me to be able to > reproduce the problem you observed ? > As I'm not sure if you can reproduce it easily without my environment (that damn x86_64 gcc4 on SuSE10), I digged a little bit deeper, and here is a new theory: The compilation fails in skins/native/libs/task.c (there exist similar files in other skins as well). The error: structures in <linux>/include/asm/sigcontext.h are being redefined. Unfortunately, gcc does not tell me where the first definition was. But here is my finding: commenting out #include <signal.h> in libs/task.c makes that error disappear. Following the include chain of /usr/include/signal.h (userspace headers...), you get to /usr/include/bits/sigcontext.h. Bingo. On the x86_64 box all structs are defined here according to the target address width. And as /usr/include/bits/sigcontext.h and <linux>/include/asm/sigcontext.h do not exclude each other, we get redefines. To sum up, I still think that kernel headers need to be avoided in userspace. Or we have to work around such issues case-by-case... Jan
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