Changeset ea562ee9 in rtems for c/src/exec/score

Patch from Ralf Corsepius <corsepiu@…>:

After upgrading my linux box to the brand new SuSE 6.2 release, which is
glibc-2.1 based, I came across a bug in RTEMS - IIRC, I even warned you
about it about 1/2 a year ago, but nothing has been done since then :-.

The *.m4 macros to check for SYSV/IPC are broken for linux/glibc2.1,
because they assume that linux always defines union semun, which isn't
true anymore for glibc2.1 (the manpage for semctl states _X_OPEN
specifies it this way). Therefore I have tried to implement a more
general approach for handling SYSV for unix/posix which checks for
presence of struct semun, instead of trying to evaluate OS specific
preprocessor symbols.

This approach is a bit adventureous, because I only tested it with
linux/glibc2.1 and linux/libc5, but not under other Unix variants RTEMS
supports. I am quite confident it will work on other hosts, too, but who
knows :-.

[FYI: I think this might also is the cause of some problems with RedHat?
6.X / Mandrake linux recently reported on the rtems list -- rtems-4.0.0
can not be build for posix on any glibc2.1 based host]

Furthermore the patch below contains a couple of minor fixes and
configuration cleanups, which IMO should be applied before releasing a
new snapshot.

To apply this patch:

cd <source-tree>
patch -p1 < rtems-rc-19990709-8.diff
./autogen