[llvm-dev] LLVM Weekly - #292, August 5th 2019

[Alex Bradbury via llvm-dev]

LLVM Weekly - #292, August 5th 2019
===================================

If you prefer, you can read a HTML version of this email at
<http://llvmweekly.org/issue/292>.

Welcome to the two hundred and ninety-second 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

LLVM 9.0.0-rc1 [has been
tagged](http://lists.llvm.org/pipermail/llvm-dev/2019-July/134215.html).

You can find out more about the LLVM project's move to GitHub [on the LLVM
blog](http://blog.llvm.org/2019/08/the-llvm-project-is-moving-to-github.html).


## On the mailing lists

* Leonard Chen
[proposes](http://lists.llvm.org/pipermail/llvm-dev/2019-August/134326.html)
switching to the new pass manager by default, now that 9.0 has branched.

* David Greene wrote an RFC on [strong typedef utilities for
LLVM](http://lists.llvm.org/pipermail/llvm-dev/2019-August/134302.html), which
describes utility classes intended to increase type safety within the LLVM
codebase.

* A major blocker to transitioning the LLVM codebase to C++14 [has now been
cleared](http://lists.llvm.org/pipermail/llvm-dev/2019-August/134358.html).
Now that Google have migrated to libc++, the migration plan can [move
forwards](http://lists.llvm.org/pipermail/llvm-dev/2019-August/134360.html).

* Alex L shared an RFC on [improving Clang's
FileManager](http://lists.llvm.org/pipermail/cfe-dev/2019-July/063022.html),
which right now model file entries with multiple names correctly.

* Michael Kruse
[queries](http://lists.llvm.org/pipermail/llvm-dev/2019-August/134317.html)
whether LLVM can optimise based on the assumption that stack overflow is
undefined behaviour, and how this might interact with the
noreturn/nounwind/willreturn function attributes.

* Rui Ueyama
[proposes](http://lists.llvm.org/pipermail/llvm-dev/2019-July/134263.html)
adding an LLD feature to generate a build dependency file, similar to the
`-MD` flag for Clang and GCC.

* Bardia Mahjour [shares
minutes](http://lists.llvm.org/pipermail/llvm-dev/2019-July/134280.html) from
the loop optimisation working group.


## LLVM commits

* An LLVM bitstream-based remark serializer was introduced. This has two
serialisation modes: separate and standalone.
[r367364](https://reviews.llvm.org/rL367364).

* Unnamed function arguments are now printed with their automatically
generated name (e.g. "i32 %0") in definitions.
[r367755](https://reviews.llvm.org/rL367755).

* A new Alignment type was introduced to the LLVM codebase.
[r367393](https://reviews.llvm.org/rL367393).

* APInt gained a new clearLowBits() method.
[r367287](https://reviews.llvm.org/rL367287).

* The git-llvm helper will now ask for confirmation if it would push multiple
commits. [r367321](https://reviews.llvm.org/rL367321).

* The AArch64 backend gained support for "tagged globals", where global
variable addresses may include a pointer tag in bits 53-63.
[r367475](https://reviews.llvm.org/rL367475).

* The `raw_ostream` interface was improved to allow you to "write" colours
using `operator<<`. [r367649](https://reviews.llvm.org/rL367649).


## Clang commits

* A new `-Wimplicit-float-conversion` warning was introduced.
[r367497](https://reviews.llvm.org/rL367497).

* clang-tidy gained a new google-upgrade-googletest-case checker which updates
uses of a deprecated API. [r367263](https://reviews.llvm.org/rL367263).


## Other project commits

* libcxx gained allocator benchmarks.
[r367722](https://reviews.llvm.org/rL367722).

* The documentation on building LLDB was updated with better coverage of the
monorepo and CMake caches. [r367302](https://reviews.llvm.org/rL367302).