[pacman-dev] [PATCH] Fix a mistake in the cross-compilation fix

[Xavier Chantry]

On Fri, Apr 9, 2010 at 4:30 PM, Dan McGee <dpmcgee at gmail.com> wrote:
> On Fri, Apr 9, 2010 at 8:21 AM, Matthias Lanzinger <mlaenz at gmail.com> wrote:
>> I noticed a serious mistake in my previous patch.
>> -lssl and -lcrypto were beeing added to $LIBS and
>> by that they were added as linker flags during compilation.
>> This overruled the --as-needed flag and causes ssl to be directly
>> linked to pacman.
>>
>> Signed-off-by: Matthias Lanzinger <mlaenz at gmail.com>
>
> I'm actually going to revert most of this link stuff as you are still
> not doing it right, and I want to make our library linking process a
> bit saner.
>
>> ---
>>  configure.ac |    4 ++--
>>  1 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/configure.ac b/configure.ac
>> index d0fed48..9bb0cd1 100644
>> --- a/configure.ac
>> +++ b/configure.ac
>> @@ -142,8 +142,8 @@ if test "x$internaldownload" = "xyes" ; then
>>        AC_MSG_RESULT(yes)
>>        AC_DEFINE([INTERNAL_DOWNLOAD], , [Use internal download library])
>>        # Check for a download library if it was actually requested
>> -       AC_CHECK_LIB([fetch], [fetchParseURL], [AC_SUBST([LIBS], ["-lfetch -lssl -lcrypto -ldl $LIBS"])],
>> -               AC_MSG_ERROR([libfetch is needed to compile with internal download support]), [-lssl -lcrypto -ldl] )
>> +       AC_CHECK_LIB([fetch], [fetchParseURL], [AC_SUBST([LIBS], ["-lfetch -ldl $LIBS"])],
>> +               AC_MSG_ERROR([libfetch is needed to compile with internal download support]), [-lcrypto -ldl] )
> The [-lcrypto -ldl] in the second line here is completely wrong if I'm
> reading autoconf docs correctly. This is meant to be fallback
> libraries, not additional dependencies of the original library.
>

http://www.gnu.org/software/hello/manual/autoconf/Libraries.html
— Macro: AC_CHECK_LIB (library, function, [action-if-found],
[action-if-not-found], [other-libraries])
If linking with library results in unresolved symbols that would be
resolved by linking with additional libraries, give those libraries as
the other-libraries argument, separated by spaces: e.g., -lXt -lX11.
Otherwise, this macro may fail to detect that library is present,
because linking the test program can fail with unresolved symbols. The
other-libraries argument should be limited to cases where it is
desirable to test for one library in the presence of another that is
not already in LIBS.

I don't know how to find how libfetch was built though. Why isn't the
linker able to resolve this automatically ?
Otherwise would that be pkg-config job ?

I thought this whole mess was only needed for a static build, not dynamic one.
That's why I bothered to add pkg-config support to libarchive :
$ pkg-config --libs --static libarchive
-larchive -lacl -lattr -lcrypto -lexpat -llzma -lbz2 -lz
$ readelf -d /usr/lib/libarchive.so
 0x0000000000000001 (NEEDED)             Shared library: [libacl.so.1]
 0x0000000000000001 (NEEDED)             Shared library: [libattr.so.1]
 0x0000000000000001 (NEEDED)             Shared library: [libcrypto.so.1.0.0]
 0x0000000000000001 (NEEDED)             Shared library: [libexpat.so.1]
 0x0000000000000001 (NEEDED)             Shared library: [liblzma.so.0]
 0x0000000000000001 (NEEDED)             Shared library: [libbz2.so.1.0]
 0x0000000000000001 (NEEDED)             Shared library: [libz.so.1]
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.6]