Skip to Content.
Sympa Menu

freetds - Re: [freetds] DB connection library and dynamic linking

freetds AT lists.ibiblio.org

Subject: FreeTDS Development Group

List archive

Chronological Thread  
  • From: "James K. Lowden" <jklowden AT freetds.org>
  • To: FreeTDS Development Group <freetds AT lists.ibiblio.org>
  • Subject: Re: [freetds] DB connection library and dynamic linking
  • Date: Sun, 26 Sep 2010 17:11:45 -0400

Julian Amso wrote:
>
> Thank for the different suggestions. There is bureaucratic situation of
> not me having control over the package compilation, installation on the
> machine including root access. It looks like a nice solution of the
> namespace issue.

Yes, I hope it's clear that the change I suggested touches only FreeTDS.
Your source code and build procedure are unmodified.

> I wonder what would happen if a recompile the application and staticly
> link the FreeTDS application and keep the remaining libraries to be
> loaded dynamically.

The static linker will satisfy all ct-lib symbols it can from the static
library, including those you might hope would be left until run time.

> I also found an interesting article about direct binding symbol
> references using a mapfile.

The fundamental problem you face AIUI is that two parts of your object
code both refer to e.g. ct_connect() but want different implementations of
it. No amount of linker hocus pocus can link some references to one
library and others to another.

Well, that might not be 100% true. The linker knows two things: the
symbol name and the name of the module (the .o file) referencing it. In
theory, the linker could distinguish based on module name, and you could
provide it a map listing which modules are to be linked to which
libraries.

The only difficulty there is that I've never heard of such a feature. You
might have to write your own linker. I think renaming the symbols will be
easier, though. ;-)

--jkl




Archive powered by MHonArc 2.6.24.

Top of Page