[PATCH] XDM: Fix FTBFS with gold or recent gcc releases.

[Fernando Lemos]

On Sat, Feb 19, 2011 at 6:47 PM, Alan Coopersmith
<alan.coopersmith at oracle.com> wrote:
> On 02/19/11 10:28 AM, Mark Kettenis wrote:
>>> Date: Sat, 19 Feb 2011 18:03:04 +0000
>>> From: Fernando Lemos <fernandotcl at gmail.com>
>>>
>>> /usr/bin/ld: session.o: undefined reference to symbol 'dlclose@@GLIBC_2.2.5'
>>> /usr/bin/ld: note: 'dlclose@@GLIBC_2.2.5' is defined in DSO
>>> /lib64/libdl.so.2 so try adding it to the linker command line
>>> /lib64/libdl.so.2: could not read symbols: Invalid operation
>>> collect2: ld returned 1 exit status
>>> make[2]: *** [xdm] Error 1
>>>
>>> Adding AC_SEARCH_LIBS([dlopen], [dl]) solves it, not sure there isn't
>>> a better way to do it?
>>
>> Looks like AC_LIBTOOL_DLOPEN does the check for dlopen/-ldl, but
>> doesn't automatically add it.  You'll need to add @LIBADD_DL@ and/or
>> $(LIBADD_DL) in the appropriate places.  That's probably a better way
>> to fix this issue.
>
> Unfortunately, it looks like that worked with libtool 1.x but I don't
> see it in libtool 2.2.10.   I'm not seeing any obvious way to get the
> results of libtools check into a variable we can use.
[...]

Indeed, I did some tests with libtool 2.2 and couldn't get LIBADD_LD
to show up. The documentation for libtool 2.4 doesn't mention
LIBADD_LD either, and nothing similar is documented for
AC_LIBTOOL_DLOPEN or LT_INIT.

Should I go ahead and submit a new patch that uses AC_SEARCH_LIBS?

Thanks,