[m-dev.] Version of Mercury to Compile Mercury

[Paul Bone]

On Mon, Jun 29, 2015 at 01:07:38AM +1000, Mark Brown wrote:
> On Tue, Jun 23, 2015 at 4:50 AM, Zoltan Somogyi
> >
> > I have been thinking of a way to set things up that would make this simpler.
> > We could put a zero-size file into the source distribution (named something
> > like ".this_is_a_src_dist" or similar) to act as a flag. The configure script would
> > detect this, and ignore any installed mmc, out-of-date or not, to make sure
> > that the .c files supplied by the source distribution are not accidentally overwritten.
> > The last action of "make install" could be then to delete this file, if it exists.
> >
> > What do people think?
> 
> I agree. Few users would actually benefit from bootstrapping source
> distributions from existing installs, and even then they would need to
> override that behaviour from time to time.

I also agree, however sometimes I do want to do this.  On a 64bit machine,
which is all of them, I will install Mercury once, then bootstrap the same
version using the installed version.  Doing this gives me 3 tag bits for the
compiler.  It no-longer affects applications since we started using
hlc.gc.pregen for source distributions, however it will still give me a
slightly faster compiler.

Whichever "make clean" removes the .c files should also remove this file.

> If you call the file DO_NOT_USE_EXISTING_MMC then it should be easy to
> remember which file to remove if the rare case that someone wants to
> override the new behaviour.

I also agree.


-- 
Paul Bone
http://www.bone.id.au