Re: CHECK_STRUCTS/dmpstruct.h mechanism is broken.

[Daniel Colascione]

>> From: Paul Eggert <address@hidden>
>> Date: Thu, 11 Apr 2019 11:31:36 -0700
>>
>> On 4/11/19 2:35 AM, Robert Pluim wrote:
>> > Much as I dislike Autoconf, what would you have us replace it with?
>>
>> I was thinking of using just standard tools (as per the GNU Coding
>> Standards) along with GNU Make - and, once the Emacs core is built, we
>> can use Emacs itself. Although we started assuming GNU Make in Emacs 25,
>> we haven't been using GNU Make's features fully and some of its features
>> could effectively replace the need for Autoconf.
>
> You want to test for system-dependent features with Make?  How does
> one do that?  All those HAVE_foo macros in the sources -- how do you
> compute them with Make?  Wouldn't we end up with heaps of Make
> wizardry only a few understand?

GNU make can run arbitrary shell commands. You'd just write

  HAVE_foo := $(shell ./test-foo)

or something like that, then have a separate make function that compiled
all these tests into a header. I don't think it's a *good* idea, but it
works, and you can do surprisingly complex things this way.

>> A benefit of this approach would be faster builds. Right now the biggest
>> bottleneck on my system is the time to run 'configure' whenever I make a
>> trivial change to configure.ac or whatever. I *hate* that.
>
> IME, the slowest part is byte compilation of Lisp files.  Of course,
> that is only a significant factor when you bootstrap or rebuild large
> parts of Emacs, but still.

Someday, it'd be nice to get rid of explicit byte compilation entirely and
rely on either a JIT or automatic recompilation on load.