configure: fix lustre detection

[ggouaillardet]

No description provided.

[ggouaillardet]

@edgargabriel could you please review this ?

also, do you have any recollection why we OPAL_LOG_COMMAND() instead of a simpler AC_COMPILE_IFELSE() ?

OPAL_CHECK_PACKAGE() now automatically checks <dir>/lib64 and <dir>/lib so I think there is also room to simplify that part.

[edgargabriel]

@ggouaillardet sorry for the delay: the OPAL_LOG_COMMAND was not introduced by me, if I recall correctly @jsquyres added a fix sometime in spring, maybe it stems from his commit.

[roblatham00]

I'll only point out that ROMIO does this differently (not to say correctly/incorrectly). Autotools guidelines say header files and libraries should be passed in as part of CFLAGS, LIBS, and LDFLAGS, and the --with-whatever argument is for... I don't know something else. I find the distinction annoying, personally, but have tried to stick to "the autotools way".

[roblatham00]

from personal experience, AC_COMPILE_IFELSE is not only simpler but has solved or preempted more than one portability issue for MPICH/ROMIO.

[jsquyres]

@roblatham00 OPAL_CHECK_PACKAGE ultimately invokes things like AC_CHECK_HEADERS and AC_SEARCH_LIBS -- we don't try to roll that stuff ourselves. OPAL_CHECK_PACKAGE is just a wrapper around checking for multiple things in a package: header files, libraries, ...etc. We've been using it for years. Example:

          [OPAL_CHECK_PACKAGE([$2],
                              [netlink/netlink.h],
                              [nl],
                              [nl_connect],
                              [-lm],
                              [$1],
                              [],
                              [opal_libnlv1_happy=1],
                              [opal_libnlv1_happy=0])],

Which looks for netlink/netlink.h, and looks for the nl_connect symbol in -lnl, and also adds -lm to $LIBS before checking for that. I forget what $6 and $7 are for offhand, but they also influence what/how things are searched for. $8 is what to do if everything is found; $9 is what to do if anything is not found.

And as for the difference between AC_COMPILE_IFELSE and OPAL_LOG_COMMAND, we added the OPAL_LOG_COMMAND macro several years ago as a way to make sure that the command that is run (and its output) are emitted to config.log. In certain cases, this is extraordinarily helpful (e.g., because AC_COMPILE_IFELSE output is not emitted to config.log). Hence, OPAL_LOG_COMMAND is not a replacement for AC_COMPILE_IFELSE -- rather, it's just a different tool that can be used (and isn't limited to just compiling things -- you can run any command).

[ggouaillardet]

:bot:ompi:retest

[awlauria]

bot:ompi:retest