[llvm-dev] LLVM Weekly - #304, October 28th 2019

[Alex Bradbury via llvm-dev]

LLVM Weekly - #304, October 28th 2019
=====================================

If you prefer, you can read a HTML version of this email at
<http://llvmweekly.org/issue/304>.

Welcome to the three hundred and fourth issue of LLVM Weekly, a weekly
newsletter (published every Monday) covering developments in LLVM, Clang, and
related projects. LLVM Weekly is brought to you by [Alex
Bradbury](https://www.linkedin.com/in/alex-bradbury/). Subscribe to future
issues at <http://llvmweekly.org> and pass it on to anyone else you think may
be interested. Please send any tips or feedback to <asb at asbradbury.org>, or
@llvmweekly or @asbradbury on Twitter.


## News and articles from around the web

The 2019 LLVM Dev Meeting took place in San Jose last week and was a huge
success. 630 attendees, a 17.5% growth in attendance vs last year. It was the
Largest program yet with 2 keynotes, 26 technical talks, 11 tutorials, 2
panels, 4 BofS, 4 Student Research Competition presentations, 23 lightning
talks and 31 proposed roundtables. Thanks to the organisers, sponsors,
speakers, and attendees.

The migration from SVN to a git repo hosted by GitHub [is now
complete](http://lists.llvm.org/pipermail/llvm-dev/2019-October/136107.html).
Many thanks to Tom Stellard and everyone else involved in this effort. LLVM
Weekly now uses git short hashes to refer to commits.


## On the mailing lists

* James Y Knight kicked off an RFC thread on [switching from Bugzilla to
GitHub
issues](http://lists.llvm.org/pipermail/llvm-dev/2019-October/136162.html).
Although there is plenty of interest, there are also a number of challenges to
be resolved. Anton Korobeynikov
[created a doc to collect
them](https://docs.google.com/document/d/1byEcbsxF3pL-HGGd_K6axdh87tbcsuJK3Dp6ThxGjKA/edit).

* Siva Chandra has posted a v2 of the proposal for ["ground truth files" for
libc](http://lists.llvm.org/pipermail/libc-dev/2019-October/000009.html). It
now uses TableGen rather than Python.

* Chris Bieneman shared an RFC on [future directions for the LLVM build
system](http://lists.llvm.org/pipermail/llvm-dev/2019-October/136086.html).
The proposal identifies that the build system is evolving in divergent ways
and in places is more complex than it needs to be. He proposes a number of
concrete changes to improve the situation.

* John McCall has shared an RFC on [pointer authentication for
arm64e](http://lists.llvm.org/pipermail/llvm-dev/2019-October/136091.html),
announcing that Apple would like to upstream their implementation for LLVM,
Clang, and Swift.

* Hans Wennborg
[announces](http://lists.llvm.org/pipermail/llvm-dev/2019-October/136188.html)
that a tag `llvmorg-10-init` has been created to mark "the initial commit
with major version number 10". `git describe` can now be used to create names
like `llvmorg-10-init-8348-ga4783ef58d3`.

* Thomas Preud'homme wonders if anyone has any [FileCheck feature requests /
wishlist
items](http://lists.llvm.org/pipermail/llvm-dev/2019-October/136112.html).

* David Greene has shared [v3 of his LLVM complex types
proposal](http://lists.llvm.org/pipermail/llvm-dev/2019-October/136100.html).

* Gábor Márton [summarises discussion at the ASTImporter round
table](http://lists.llvm.org/pipermail/cfe-dev/2019-October/063704.html) at
the LLVM Dev Meeting.

* Dmitriy Borisenkov penned an RFC on [non 8-bit bytes in
LLVM](http://lists.llvm.org/pipermail/llvm-dev/2019-October/136115.html).
David Chisnall [asks for further
clarification](http://lists.llvm.org/pipermail/llvm-dev/2019-October/136158.html)
about the needs of the TON target.


## LLVM commits

* The Arm backend started to gain IR intrinsics for MVE instructions.
[1b45297](https://reviews.llvm.org/rG1b45297e013),
[ceeff95](https://reviews.llvm.org/rGceeff95ca48).

* The git-llvm script now pushes to github.
[3bf7fdd](https://reviews.llvm.org/rG3bf7fddeb05).

* The GlobalISel documentation has been restructured.
[feab033](https://reviews.llvm.org/rGfeab0334f57).

* The RISC-V backend gained support for `-ffixed-xX` flag for reserving GPRs.
[aed9d6d](https://reviews.llvm.org/rGaed9d6d64a3).


## Clang commits

* Implementation of C++20 concepts continues with the addition of constraint
enforcement and diagnostics.
[ffa214e](https://reviews.llvm.org/rGffa214ef228).

* clang-objc-fuzzer was introduced.
[e5ecba4](https://reviews.llvm.org/rGe5ecba4f53e).

* C++20 support for explicitly defaulted comparison functions was added.
[d052a578](https://reviews.llvm.org/rGd052a578de5).

* Initial intrinsics were implemented for Arm MVE.
[08074cc](https://reviews.llvm.org/rG08074cc9655).


## Other project commits

* LLDB gained initial support for Arm register contexts on Windows.
[a59444a](https://reviews.llvm.org/rGa59444a3560).

* It's now possible to build the sanitizers for RISC-V 64-bit.
[977205b](https://reviews.llvm.org/rG977205b595c).