Subject: Re: ld_elf.so proposal for selecting hw/dependent libraries
To: Jason Thorpe <thorpej@nas.nasa.gov>
From: Christos Zoulas <christos@zoulas.com>
List: tech-toolchain
Date: 12/12/1999 17:25:45
On Dec 12,  2:06pm, thorpej@nas.nasa.gov (Jason Thorpe) wrote:
-- Subject: Re: ld_elf.so proposal for selecting hw/dependent libraries

| Great!  This is cool!
| 
| How does it handle defaults, tho?  I suppose we have library build
| infrastructure to take care of this?

The defaults will be done by the build system using symlinks. This is
so, that even with a missing ld.so.conf the system functions properly.

| Also, what about just portions of libraries?  e.g. BWX-optimized string
| routines on Alpha?

This becomes harder. Maybe providing libstrbwx.so and enhancing the syntax
to be:

c	cpu_model	21164A,21164PC,21264:strbwx,c

So that strbwx is prepended to libc, and it resolves the symbols before
libc is scanned. I'll have to be careful though, not to evaluate the rules
recursively :-)

| Also, do the return values have to be ints, or can they be strings?

Yes, they are all normalized to strings [so I can use simpler data structures]

| I'm thinking of the Alpha case again, here.  We can't just key off
| "21164" ... BWX appears in "21164A" (EV56), "21164PC" (PCA56), and
| "21264" (EV6).

Good point.

christos