some question about gc

[Ian Lance Taylor]

"zouq" <zouqiong@ict.ac.cn> writes:

> yes, as you have suggested, i have already read the gcc-int about garbage
> collection, and i still can`t get the imformation i want.
> i want to know the following constructs:
> gt_ggc_cache_rtab, gt_ggc_deletable_rtab ....
> acording to what rules to genenrate them,
> i read some of the gengtype.c, and i still don`t understand it. :(

Can you ask a more specific question?  What do you really want to
know?

The cache_rtab symbols wind up in files specific to particular
languages.  The effect is that gt_ggc_cache_rtab is defined once in a
specific backend (e.g., cc1, cc1plus, etc.).  It lists GC roots which
use "if_marked" in the GTY description--see the docs.

The deletable_rtab symbols are similar, but list GC roots which use
"deletable".

> and now i am thinking that why use garbage collection in gcc,
> is it because of its high efficiency?

Ha ha, no.  See Nix's reply.

Ian