Ideas and questions about dynamic linking

[Howard B. Golden]

I've been thinking about the dynamic linking proposal and I have some 
ideas and questions. I am trying to clarify (in my mind) the 
requirements / like-to-haves.

Q1. Is LGPL code acceptable? If so, you might want to consider gmodule 
from glib (see http://library.gnome.org/devel/glib/unstable/glib-
Dynamic-Loading-of-Modules). According to their documentation, they've 
already done all the work to make dynamic linking work on many 
platforms.

Q2. How is dynamic linking related to GHCi interpretation? Will it ever 
be necessary to be able to link dynamically _to_ interpreted code 
objects? (Linking _from_ interpreted code shouldn't be a problem.)

Q3. Would it be acceptable to require compilation with PIC and the use 
of the system linker to turn modules into shared objects in order to use 
dynamic linking? Is it necessary for GHCi to be able to load .o files 
directly?

Q4. Currently the Haskell linker (rts/Linker.c) maintains a symbol 
table. Why is this necessary? What would happen if the Haskell code 
called the system's symbol lookup (e.g., dlsym on POSIX or 
g_module_symbol from gmodule)?

Q5. Are there any platforms that GHCi runs on that don't support shared 
libraries and dynamic linking?

Thanks,

Howard