Programming

for example, I have a static lib name liba.a
it offers some interface such a1();a2();
but i do not have the source code of liba.a;
If i would like to create a shared object, and offer the similar interface of
a1 and a2;

Is there a way to fulfill such requirement?
thanks.

I don't think you can magically transform statically linked code into relocatable one. One workaround would be using rpc.

Thanks jlliagre.

Do you mean that i implement an rpc inforstructure using that statlic lib,
and using rpc to call its interfaces?

yes, that's the idea.

Thanks Jlliagre.
That's quite a large project than simply use the statlic lib and rebuild my program.

Why not just link it as a static library? You gain nothing by converting it to a shared object, and you'd add an extra run-time dependency to your app.

Even if you use it as a shared object you still have to rebuild your app.

And FWIW, you can usually convert a static archive into a shared object like this:

Code:

-bash-3.2$ ar -x libmylib.a
-bash-3.2$ ld -o libmylib.so *.o

The shared object almost certainly won't have been compiled to be position-independent, so it will require some more work for your run-time linker to load (and may not load on some systems - like a 64-bit shared object on Solaris), but it should work otherwise exactly the same as it it were linked in statically as long as it's relatively basic and simple code.

Converting a static archive into a shared object like that basically gains you nothing in functionality, though, and comes at the expense of additional run-time dependencies.

Just create your wrapper interface functions and call these functions from there. Compile with --SHARED flag usig gcc.

---------- Post updated 05-06-10 at 12:49 PM ---------- Previous update was 05-05-10 at 08:43 PM ----------

Great Advice and very true.
However, on my Linux system what works is as follows:

Code:

-bash-3.2$ ar -x libmylib.a
-bash-3.2$ ld --shared -o libmylib.so *.o

Thanks.