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Re: LMDB test assertion failures on Linux/MIPS

hyc@symas.com said:
> Martin Lucina wrote:
> >martin@lucina.net said:
> >>The only thing which is somewhat unusual is that I use musl libc
> >>(http://www.musl-libc.org/). However I also use this on my x86_64 dev boxes
> >>and everything works fine.
> >>
> >>I'm currently building an eglibc toolchain for MIPS just to rule that
> >>possibility out.
> >
> >Ruled out.
> >
> >Built a toolchain for mips-unknown-linux-gnu, using GCC 4.8.1 (crosstool-NG
> >1.19.0) and configured with eglibc 2.17. mtest still fails with the same
> >symptoms.
> >
> >Martin
> >
> I wouldn't expect the libc to have affected this. I note that
> compiling with -Wcast-align produces no warnings on my x86-64 build,
> so it appears to be compiler-specific and not library specific.

The docs for -Wcast-align say:

  Warn whenever a pointer is cast such that the required alignment of the
  target is increased. For example, warn if a char * is cast to an int * on
  machines where integers can only be accessed at two- or four-byte
  boundaries. 

So the warning is arch-specific and thus will not trigger on x86(-64) which
does not require aligned accesses for integers.

In a previous email you mentioned LMDB works fine on SPARC. That is not
what I see here, with 0.9.11 freshly cloned from gitorious:

$ uname -a
SunOS erzika 5.10 Generic_141414-10 sun4u sparc SUNW,Sun-Blade-100
$ mkdir testdb
$ dbx ./mtest
(...)
(dbx) run   
Running: mtest 
(process id 20724)
Reading libc_psr.so.1
t@1 (l@1) signal SEGV (no mapping at the fault address) in mdb_txn_renew0 at 0x12ea4
0x00012ea4: mdb_txn_renew0+0x01e4:      ld       [%g2 + 76], %g2
(dbx) bt
current thread: t@1
=>[1] mdb_txn_renew0(0x2fa88, 0x0, 0xffffffff, 0x0, 0x2f9f8, 0x2fa88), at 0x12ea4 
  [2] mdb_txn_begin(0xc, 0x0, 0x0, 0xffbff9bc, 0x2fa88, 0x2f9f8), at 0x1425c 
  [3] main(0x2f638, 0xffbff9bc, 0xffbffa34, 0x2f55c, 0x2f9f0, 0xee), at 0x1ded8 

I note that the CSW GCC 4.6.3 I'm using on SPARC also produces warnings
when building mdb with -Wcast-align.

Martin