Say I have a.so and b.so. Can I produce c.so as a single shared library with all the functions exported by a and b, of course resolving all intra-dependencies (i.e. all functions of b.so called by a.so and the other way around)?
I tried
gcc -shared -Wl,soname,c.so -o c.so a.so b.so
but it doesn't work.
Same goes if I archive a.o and b.o in a.a and b.a (which shouldn't modify a.o and b.o), and do
gcc -shared -Wl,soname,c.so -o c.so a.a b.a
Thanks
In practice it is not possible.
From linker point of view, a SO library is a final product that does not contain relocation information required for linking.
If you have access to either source or object files for both libraries, it is straightforward to compile/link a combined SO from them.
Merging multiple shared libraries into one is indeed practically impossible on all UNIXen, except AIX: the linker considers the .so a "final" product.
But merging archives into .so should not be a problem:
gcc -shared -o c.so -Wl,--whole-archive a.a b.a -Wl,--no-whole-archive