Re: (ITS#8034) lmdb-0.9.14 | Undefined symbols for architecture ppc: "_posix_memalign" referenced from _mdb_env_copyfd2 | ld: symbol(s) not found for architecture ppc

[h.b.furuseth@usit.uio.no]

On 23/01/15 18:10, hyc@symas.com wrote:
>> LMDB should not be pulled separately from OpenLDAP.  I.e., only the bundled
>> version of LMDB should be used with a given version of OpenLDAP.
>
> I've already had this conversation with the gentoo maintainers; they
> refuse to listen to reason. It's all their problem now.

Still, memalign() is a problem.  mdb.c defines HAVE_MEMALIGN,
but it may be wrong for the user to -D"HAVE_MEMALIGN" since that
may omit whatever #include file declares it. <malloc/malloc.h>
(some Apple stuff I think), <malloc.h> dunno what else.

We could drop memalign.  malloc(desired space + 1 OS page), then
adjust for alignment.  On machines with a sane linear address
space where we can tell alignment from the address, anyway.

On weirder hosts, you care about them, omit alignment altogether
if posix_memalign is missing.  And omit O_DIRECT/F_NOCACHE in
mdb_env_copy2().  I gather those are why we need alignment.

Branch "mdb/memalign" in <git://git.uio.no/u/hbf/openldap.git>
has draft code.

Daniel: You can try that branch, and configure with
CPPFLAGS="-DMDB_MEMALIGN_METHOD=2".


I guess the preprocessor test should be "defined(a test for
Darwin: __APPLE__, _MACOSX_ or..?)" and not __PPC__.  PowerPC is
an architecture, while features like posix_memalign are defined
by compilers/operating systems.  The macports issue disables mdb
for Darwin.  Or maybe not, I don't know Mac, Darwin, PPC or
Gentoo, or if you just said this has been resolved, so I'll stay
out of of that issue.

-- 
Hallvard