Re: [RFA] delete BLOCK_SHOULD_SORT

["Paul N. Hilfinger" <hilfingr@otisco.mckusick.com>]

> I think the changes are pretty straightforward, though I'd appreciate
> it if somebody more conversant with ada-lang.c than I am could make
> sure I'm not missing anything with my change there.

David,

OK; let me explain what Ada is up to in the various places it does
symbol lookup, and you can decide if we (ahem) need a conversation on
this (vis-a-vis this thread or the other "dictionary" threads), or if
our needs introduce no new requirements.

The problem is that some of our symbol lookups essentially require searches for 
regular expressions of the form

    (.*__)?<NAME>(___.*)?

or for 

    <NAME>(___.*)?

Not much you can do about the former, of course, with the current
setup, except scan all symbols, and that's what we do.  The second
pattern, however, can benefit for sorted blocks in an obvious way---
hence the ada-lang.c code you mentioned in an earlier message---but
doesn't need them.  That is, we take advantage of BLOCK_SHOULD_SORT
when possible.  I don't have measurements of the impact of not having
it.  There are obvious ways to use caching when performance becomes a
problem (and we currently use them).

The other property of Ada is that when we have to search global or 
all file-scope symbols, we generally want ALL matches to these patterns, or
ALL matches from a given block.

Paul Hilfinger