Re: Speeding up the bootstrap build - a quick hack.

[Andrea Corallo <akrl@sdf.org>]

Robert Pluim <rpluim@gmail.com> writes:

>>>>>> On Tue, 18 Jan 2022 09:24:04 -0500, Stefan Monnier <monnier@iro.umontreal.ca> said:
>
>     >> So if you ensured that the native compiler files were built before
>     >> that problematic .elc, then things would be ok?
>
>     Stefan> The problem is that you need one rule
>
>     Stefan>     bytecomp.elc: bytecomp.el
>     Stefan>         ELC ...
>
>     Stefan> to build the byte-compiled compiler, and then another rule:
>
>     Stefan>     bytecomp.elc: bytecomp.el bytecomp.elc comp.elc macroexp.elc cconv.elc ...
>     Stefan>         ELC+ELN ...
>
>     Stefan> to build the native compiled compiler using the byte-compiled compiler
>     Stefan> (which is much faster than the interpreted compiler).
>
> Ah, weʼre lying to make. No wonder weʼre having problems :-)
>
>     Stefan> In an ideal world the second rule would not have `bytecomp.elc` as its
>     Stefan> target but would have something like `bytecomp.eln` instead, but we have
>     Stefan> not yet been able to teach Make how to compute the name of the generated
>     Stefan> `.eln` file (it's not just `bytecomp.eln` but includes some hash of the
>     Stefan> Emacs binary).
>
> Thereʼs no other file or directory name that contains that hash? Could
> we do a dummy compile of an empty .el using the native compiler and
> derive the hash from that? (and then compile the native compiler with
> the byte compiler).
>
> Robert

Part of the hash is computed also using the content of the .el file so
the empty .el trick would not work.

  Andrea