Commit Graph

4 Commits

Author SHA1 Message Date
Arvind Sankar f040a7b0f8 Fix up FIND_SYSTEM_LIBRARY to work with cross-compiling
Make FIND_SYSTEM_LIBRARY respect a configured sysroot, otherwise it
might find headers from the build machine and assume the library is
available on the host/target.

Tighten up error checking: if pkg-config or the user specified _CFLAGS
or _LIBS but we can't find the header/library, issue a fatal error.

Fix the -L flag to /usr/local/lib instead of just /usr/local.

Clean out the _CFLAGS and _LIBS if we located something that we later
find doesn't work.

Rename FIND_SYSTEM_LIBRARY into the ZFS_AC_ scope.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes #10538
2020-07-10 14:26:40 -07:00
Arvind Sankar 4d61ade1a3 Clean up lib dependencies
libzutil is currently statically linked into libzfs, libzfs_core and
libzpool. Avoid the unnecessary duplication by removing it from libzfs
and libzpool, and adding libzfs_core to libzpool.

Remove a few unnecessary dependencies:
- libuutil from libzfs_core
- libtirpc from libspl
- keep only libcrypto in libzfs, as we don't use any functions from
  libssl
- librt is only used for clock_gettime, however on modern systems that's
  in libc rather than librt. Add a configure check to see if we actually
  need librt
- libdl from raidz_test

Add a few missing dependencies:
- zlib to libefi and libzfs
- libuuid to zpool, and libuuid and libudev to zed
- libnvpair uses assertions, so add assert.c to provide aok and
  libspl_assertf

Sort the LDADD for programs so that libraries that satisfy dependencies
come at the end rather than the beginning of the linker command line.

Revamp the configure tests for libaries to use FIND_SYSTEM_LIBRARY
instead. This can take advantage of pkg-config, and it also avoids
polluting LIBS.

List all the required dependencies in the pkgconfig files, and move the
one for libzfs_core into the latter's directory. Install pkgconfig files
in $(libdir)/pkgconfig on linux and $(prefix)/libdata/pkgconfig on
FreeBSD, instead of /usr/share/pkgconfig, as the more correct location
for library .pc files.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes #10538
2020-07-10 14:26:00 -07:00
Richard Yao e853ba3519 Cleanup linking
I noticed during code review of zfsonlinux/zfs#4385 that the author of a
commit had peppered the various Makefile.am files with `$(TIRPC_LIBS)`
when putting it into `lib/libspl/Makefile.am` should have sufficed. Upon
further examination, it seems that he had copied what we do with
`$(ZLIB)`. We also have a bit of that with `-ldl` too.  Unfortunately,
what we do is wrong, so lets fix it to set a good example for future
contributors.

In addition, we have multiple `-lz` and `-luuid` passed to the compiler
because each `AC_CHECK_LIB` adds it to `$LIBS`. That is somewhat
annoying to see, so we switch to `AC_SEARCH_LIBS` to avoid it.  This is
consistent with the recommendation to use `AC_SEARCH_LIBS` over
`AC_CHECK_LIB` by autotools upstream:

https://www.gnu.org/software/autoconf/manual/autoconf-2.66/html_node/Libraries.html

In an ideal world, this would translate into improvements in ELF's
`DT_NEEDED` entries, but that is not the case because of a couple of
bugs in libtool.

The first bug causes libtool to overlink by using static link
dependencies for dynamic linking:

https://wiki.mageia.org/en/Overlinking_issues_in_packaging#libtool_issues

The workaround for this should be to pass `-Wl,--as-needed` in
`LDFLAGS`. That leads us to the second bug, where libtool passes
`LDFLAGS` after the libraries are specified and `ld` will only honor
`--as-needed` on libraries specified before it:

https://sigquit.wordpress.com/2011/02/16/why-asneeded-doesnt-work-as-expected-for-your-libraries-on-your-autotools-project/

There are a few possible workarounds for the second bug. One is to
either patch the compiler spec file to specify `-Wl,--as-needed` or pass
`-Wl,--as-needed` via `CC` like `CC='gcc -Wl,--as-needed'` so that it is
specified early. Another is to patch ltmain.sh like Gentoo does:

https://gitweb.gentoo.org/repo/gentoo.git/tree/eclass/ELT-patches/as-needed

Without one of those workarounds, this cleanup provides no benefit in
terms of `DT_NEEDED` entry generation. It should still be an improvement
because it nicely simplifies the code while encouraging good habits when
patching autotools scripts.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4426
2016-03-18 13:31:11 -07:00
Brian Behlendorf c9c0d073da Add build system
Add autoconf style build infrastructure to the ZFS tree.  This
includes autogen.sh, configure.ac, m4 macros, some scripts/*,
and makefiles for all the core ZFS components.
2010-08-31 13:41:27 -07:00