On 2016-03-21 17:48, l...@gnu.org wrote:
taylanbayi...@gmail.com (Taylan Ulrich "Bayırlı/Kammer") skribis:
A while back Mark raised the idea of hosting one pre-compiled
bootstrap
version of each such compiler, and use that to compile further
versions.
This way the number of blobs is one per such compiler, instead of one
for every new version of each such compiler.
It seemed like a good medium-term solution to me. I'm not sure how it
would be implemented.
I like the idea.
Often, in their implementation history, compilers are boostrapped from
something else initially, and only later to they become self-hosted and
unbootstrappable.
So in theory, it’d be possible to find, say, an old-enough GHC that
only
requires a C compiler (?), and use that to build the next version and
so
on, until we reach the latest version. I suspect the same applies to
many compilers.
This is technically possible. The main difficulty is to find what
exact
chain of compiler versions will work, and then to make sure that the
super-old compilers can build. The risk, as Andreas suggests, is that
maintaining those old versions will require dragging a whole graph of
old dependencies, recursively.
But really, we won’t know until we’ve actually tried ;-), and it’ll
be different for each compiler.
My initial attempt at packaging GHC before our current package went this
route, ultimately to no avail. The earliest publicly-available GHC
source tarball is indeed "just C", but it is machine-generated C code
much like Chicken Scheme's.
Some software archeology might be able to produce a still earlier
version of GHC from a developers private collection.
--
`~Eric
