Re: Order of linking libraries

[Philip Guenther]

On 7/11/07, Satish S <address@hidden> wrote:
> I am having a sort of circular dependencies across libraries., with extern
> params on both the libs. I am linking with gcc and not ld. I belive gcc
> internally uses ld for linking. correct me if i am wrong.

If library A requires library B and library B requires library A, then
why are they separate at all?  A circular dependency like this
suggests that the division of the objects into libraries is not on the
'natural' boundaries, which indicates that either the concepts were
poorly split to begin with or that the implementations have, for one
reason or another, been allowed to become completely non-modular.
That happens, and the previously mentioned linker options are there to
let you continue to get things done, but it should be considered a big
warning sign that your design isn't nearly as modular as it might
appear on paper.  Depending on the details, you should probably either
merge the libraries completely, split the underlying objects along
different lines, or rework the involved objects to not be
interdependent.

As for passing the options through to the linker, make sure that you
not only use the -Wl, prefix, but also that you quote the options so
that the parentheses are not treated as special syntax by the shell:

   gcc -o program obj1.o obj2.o "-Wl,-(" -lA -lB "-Wl,-)"


Philip Guenther