Thanks!
On Sun, Jun 20, 2021 at 6:42 AM <[email protected]> wrote:
> > I've got a module mymod in mymod.scm:
> >
> >[...]
> >
> > However, I can't figure out how to do the same thing with mymod as
> > non-shared objects. I tried
> >
> > csc -c -J mymod.scm
> > csc -c mymod.import.scm
> > csc -static -o trymod.static mymod.o mymod.import.o trymod.scm
> >
> > but I got
> >
> > Undefined symbols for architecture x86_64:
> >
> > "_C_mymod_toplevel", referenced from:
> > _f_138 in trymod.o
> > ld: symbol(s) not found for architecture x86_64
> > clang: error: linker command failed with exit code 1 (use -v to see
> > invocation)
> > Error: shell command terminated with non-zero exit status 256: 'clang'
> > 'mymod.import.o' 'mymod.o' 'trymod.o' -o 'trymod.static' -m64
> > -L/usr/local/Cellar/chicken/5.2.0/lib
> > /usr/local/Cellar/chicken/5.2.0/lib/libchicken.a -lm
>
> When loading a shared object, the CHICKEN runtime uses the libld API
> to obtain the entry point ("C_toplevel") to invoke top-level
> initialization code
> of the module (which also sets up global bindings, etc.). But in a
> statically
> linked executable, all entry points of linked modules must be available
> under
> a separate name, so that they can be distinguished from each other.
>
> What we do is to give the module (the binary *.o module) a name, which is
> called "unit", so mymod would have, for example, the unit name "mymod",
> which produces the entry point "C_mymod_toplevel". So you can link any
> number of separately compiled binary objects (containing modules) and
> their names don't clash.
>
> So, to make it work:
>
> csc -c -J mymod.scm -unit mymod
> # compiling the import library is not needed
> csc -static -o trymod.static -uses mymod mymod.o trymod.scm
>
> The main file (trymod) doesn't need to resolve the imports, so you can omit
> linking the import library. "-unit" gives the module a unit name, "-uses"
> tells
> the main module to invoke the toplevel of the linked module.
>
> This mechanism is a source of great confusion, but this mainly comes from
> the fact that static linking uses a facility for resolving module toplevel
> and
> initialization code from the whole module and namespacing machinery.
>
> ---
> BTW, the "csm" utility, provided by the egg of the same name, figures this
> out
> automatically, just put trymod.scm and mymod.scm into an empty directory
> and enter
>
> csm -program trymod
>
> or
>
> csm -program trymod -static
>
> Add -d and -v to see what the program is doing and how things are compiled.
>
>
> felix
>
>
--
T. Kurt Bond, [email protected], https://tkurtbond.github.io
