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Subject: Re: Problem during dlopen()
To: Konstantin Belousov <kostikbel@gmail.com>
References: <5e29e535-f91f-35fb-2a7e-324bb19b658f@digiware.nl>
 <20160705115057.GO38613@kib.kiev.ua>
Cc: FreeBSD Hackers <freebsd-hackers@freebsd.org>
From: Willem Jan Withagen <wjw@digiware.nl>
Message-ID: <3570efcb-f106-95ba-52da-972a55d2fc33@digiware.nl>
Date: Tue, 5 Jul 2016 14:22:42 +0200
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On 5-7-2016 13:50, Konstantin Belousov wrote:
> On Tue, Jul 05, 2016 at 01:13:42PM +0200, Willem Jan Withagen wrote:
>> Hi,
>>
>> I'm banging my head agains the wall because I cannot seem to get this
>> working.
>>
>> The problem is due to changing from automake to cmake building.
>>
>> But all my dlopens start failing with something like:
>> load failed dlopen(build/lib/compressor/libceph_snappy.so) or
>> dlopen(build/lib/libceph_snappy.so): build/lib/libceph_snappy.so:
>> Undefined symbol "_ZN4ceph6buffer4list8iterator7advanceEl"
>>
>> If do a lookup for  the name:
>> nm build/lib/libceph_snappy.so |grep ceph6buffer4list8iterator7advanceEl
>>
>> if give me:
>>                  U _ZN4ceph6buffer4list8iterator7advanceEl
>>
>> The parent/calling executable however has:
>> 	0000000000513de0 T _ZN4ceph6buffer4list8iterator7advanceEl
> Are you sure ?  In which symbol table (dynamic or debug) the referenced
> symbol appear ?  Check with nm -D.  If it is in debug table, you need
> --export-dynamic linker switch when creating the binary defining the
> symbols.

You are getting the other half of the point that Pietro got.
I did a blunt nm <file> not excluding any tables...

Thanx,
--WjW