Re: [rfa:symtab] Delete broken "memory mapped objfile cache"

[Daniel Berlin <dberlin@dberlin.org>]

On Nov 4, 2003, at 11:21 AM, Andrew Cagney wrote:

> Hello,
>
> 	(more, somewhat perverse bcache fallout)
>
> The "memory mapped objfile cache" (for want of a better name) is a 
> technique where by GDB creates per-objfile disk backed memory mapped 
> caches that contain the object files symbol information.  Its based on 
> the theory that, after each rebuild little is changed, and hence most 
> symbol information can be drawn from an on-disk cache, and re-read 
> from the object file.  The lit, it turns out, supports the theory.  A 
> typical debugging rebuild changes little in an executable.
>
> So why delete it?  As far as I can tell:
>
> - it hasn't worked in >4years
> - it hasn't built in >1year
> - it isn't tested
>
> I've nothing personal against the the technique.  In fact I'd like to 
> see a robust implementation backed by test cases and supporting 
> performance data.  However, I strongly object to GDB having to carry 
> around long-ago broken code.  By deleting this, we clear the decks for 
> a modern robust implementation (the original code appears to date back 
> to '92).


Actually, apple has it implemented and working.
Maybe they'd like to share?
If so, and they need that code, maybe we should keep it around for just 
a bit longer.