[tlbuild] Clang + LLVM 3.5 compilers and build advances

[Nelson H. F. Beebe]

The experience of attempting to build TeX Live releases in recent
years has shown the need for up-to-date C and C++ compilers.

The Clang + LLVM suite shows great promise, and appears to be nearer
recent ISO Standards for C and C++ than any other compiler family.
Unfortunately, in the past, that suite has proved to be quite
difficult to build successfully, and I now have build logs from over
240 attempts over the last five years.

Earlier this month, thanks to my colleague Pieter Bowman, we found a
solution that solves the build problems for many systems, and I have
documented that experience here:

	http://www.math.utah.edu/pub/llvm/

That site also provides links to shell scripts and pre-built binary
trees for sixteen different platforms of mid-July-2014 snapshots of
the developing 3.5 compiler release.

Because of library dependencies, it is still unclear how useful those
binary distributions could be, and more work is required to package
additional libraries.  Nevertheless, I'm encouraged by the progress
that I've made, and the document describes why builds will not work on
older systems (e.g., GNU/Linux Red Hat 5).

I'll be happy to hear off-list from any of you who are adventuresome
enough to try my build recipes for Clang + LLVM snapshots.

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- Nelson H. F. Beebe                    Tel: +1 801 581 5254                  -
- University of Utah                    FAX: +1 801 581 4148                  -
- Department of Mathematics, 110 LCB    Internet e-mail: beebe at math.utah.edu  -
- 155 S 1400 E RM 233                       beebe at acm.org  beebe at computer.org -
- Salt Lake City, UT 84112-0090, USA    URL: http://www.math.utah.edu/~beebe/ -
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