[openssl-users] build.info

[Jakob Bohm]

On 04/09/2018 08:55, Wouter Verhelst wrote:
> On 9/3/18 9:05 PM, Thomás Inskip wrote:
>> Does anyone know how I can specify that a specific shared library (in 
>> this case an engine) is dependent on a system-installed shared 
>> library (i.e. not built along with openssl)?.  Basically the 
>> equivalent of LDFLAGS += -lsomelib
> The GNU runtime dynamic library will honor DT_NEEDED flags of 
> libraries, too. That is,  you can just do LDFLAGS += -lsomelib on a 
> library target and it will work. Check libgtk-3.so, for instance:
>
> objdump -x /usr/lib/x86_64-linux-gnu/libgtk-3.so
>
> will show a bunch of lines like...
>
> Dynamic Section:
>   NEEDED               libgdk-3.so.0
>   NEEDED               libgmodule-2.0.so.0
>   NEEDED               libpangocairo-1.0.so.0
>   NEEDED               libX11.so.6
>   NEEDED               libXi.so.6
>   NEEDED               libXcomposite.so.1
>   NEEDED               libXdamage.so.1
> (...)
>
> Meaning, all these libraries need to be loaded for libgtk-3.so to work.
>
> Beware gotchas:
>
> - Not all rtdl implementations do so, so if you're not using a GNU 
> platform (e.g., Linux), then check the documentation of your runtime 
> dynamic linker.
> - This works for shared libraries, but not for static ones.
>
> Regards,
>
Please note that the OP is apparently asking how to specify
-lsomelib using the OpenSSL-specific build system, not the
general meaning of using shared libraries on POSIX systems.

Enjoy

Jakob
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