Re: Compilation speed

[Paul Eggert <eggert@cs.ucla.edu>]

On 8/10/20 7:33 AM, Arthur Miller wrote:

> Since Emacs requires C99 compiler (as I understand) couldn't configure
> script just check for avialability of C99 standard, OS and compiler and
> assume the headers, flags and certain functions are avialable?

Unfortunately not. Lots of implementations conform mostly to C99 but have some 
exceptions. So we can't have a single C99 test; we need individual tests to 
cover the exceptions.

That's not to say we couldn't prune 'configure'; we could. It has several tests 
that are no longer relevant on today's porting targets. The problem is finding 
the developer time to prune them. There's a lot of good stuff there mixed in 
with the cruft.

> if there is for example not strnlen
> function avialable, would it be copied/added to system to by autotools

Generally speaking the autotools don't mess with your dev-chain installation, 
for understandable reasons.

> Couldn't autotools devs, make those tests run in their
> own shell as asynchronous processes, write output to a file and then
> make a finall pass over all outputs and then decide to bail out/continue
> or take an action.

Yes, but this would require quite a rewrite, as existing scripts typically don't 
say which tests depend on which other tests' results. I'm not saying it couldn't 
be done, only that it wouldn't be that easy.