Re: [Monotone-devel] illegal instruction again [was: Re: monotone 0.11 test failures]

[Jonathan Matthew]

On Tue, Apr 06, 2004 at 12:11:37PM -0400, graydon hoare wrote:

> for reasons which aren't totally clear to me at the moment, configure 
> with CXXFLAGS set to some explicit value on the command line fails in an 
> unfortunate way. I'm obviously twiddling these flags wrong, so the above 
> is the best fix I understand how to do at the moment.

This appears to be because of the AC_CHECK_HEADERS bit inside an 'if'.
If the 'if' is not taken, the configure script was skipping somewhere
around 15 tests, resulting in all kinds of broken weirdness.

Changing this:

if test "z$CXXFLAGS" = "z"
then
    CXXFLAGS="-O2 -fno-strict-aliasing"
    # we have some sse2 code in cryptopp which is worth
    # enabling if we're on a system which can build it
    AC_CHECK_HEADERS(emmintrin.h, [CXXFLAGS="$CXXFLAGS -msse2"])
fi


to this:  (modulo a few comments, of course)

AC_CHECK_HEADERS(emmintrin.h, [CXXFLAGS_MSSE2="-msse2"])
test "z$CXXFLAGS" = "z" && CXXFLAGS="-O2 -fno-strict-aliasing $CXXFLAGS_MSSE2"

makes it at least appear to work for me.

enjoy.

-jonathan.