[LLVMdev] LLVM Weekly - #60, Feb 23rd 2015

[Alex Bradbury]

LLVM Weekly - #60, Feb 23rd 2015
================================

If you prefer, you can read a HTML version of this email at
<http://llvmweekly.org/issue/60>.

Welcome to the sixtieth 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](http://asbradbury.org).
Subscribe to future issues at <http://llvmweekly.org> and pass it on to anyone
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<asb at asbradbury.org>, or @llvmweekly or @asbradbury on Twitter.


## News and articles from around the web

LLVM/Clang 3.6.0-rc4 is [now available for
testing](http://article.gmane.org/gmane.comp.compilers.clang.devel/41432/).

A new LLVM-based tainted flow analysis tool [has been
created](http://article.gmane.org/gmane.comp.compilers.llvm.devel/82660/).
It's a tool designed to help detect timing attack vulnerabilities. An [online
demo](http://cuda.dcc.ufmg.br/flowtracker/) is available.

The March bay-area LLVM social [will take place on Thursday 5th
March](http://article.gmane.org/gmane.comp.debugging.lldb.devel/6599/), along
with the Game Developer's Conference.

The Cambridge LLVM social will take place [on Wednesday 25th
Feb](http://article.gmane.org/gmane.comp.compilers.clang.devel/41374/).

HHVM, the optimised PHP virtual machine from Facebook [plan to integrate an
LLVM-based optimisation phase](http://hhvm.com/blog/8405/coming-soon-in-hhvm).


## On the mailing lists

* Lefteris Ioannidis has [introduced
himself](http://article.gmane.org/gmane.comp.compilers.llvm.devel/82321) on
the mailing list. He is working on propagating parallelism at the IR level,
with a hope to ultimately upstream his work. He's interested in chatting to
anyone working in this area.

* Eric Fiselier [asks when libc++ can list Linux as an officially supported
platform](http://article.gmane.org/gmane.comp.compilers.clang.devel/41444/).

* Hans Wennborg is [asking for people to flesh out the 3.6 release
notes](http://article.gmane.org/gmane.comp.compilers.clang.scm/117060) with
more details.

* Hayden Livingston is working on a tool to help understand how LLVM IR
changes after optimization passes are run and [wonders about adding a new API
to support this use
case](http://article.gmane.org/gmane.comp.compilers.llvm.devel/82398). Greg
Fitzgerald points to his [handy diffdump
tool](https://github.com/garious/diffdump).

* Bruce Mitchener suggests [adding SWIG bindings to LLDB for JS and other
languages](http://article.gmane.org/gmane.comp.debugging.lldb.devel/6570).

* Zephyr Zhao has [shared his work on a GUI frontend to
LLDB](http://article.gmane.org/gmane.comp.debugging.lldb.devel/6546).


## LLVM commits

* The coding standards document has been updated now that MSVC 2012 support
has been dropped. [r229369](http://reviews.llvm.org/rL229369).

* The Orc API continues to evolve. The JITCompileCallbackManager has been
added to create and manage JIT callbacks.
[r229461](http://reviews.llvm.org/rL229461).

* A new pass, the bit-tracking dead code elimination pass has been added. It
tracks dead bits of integer-valued instructions and removes them when all bits
are set. [r229462](http://reviews.llvm.org/rL229462).

* The SystemZ backend now supports all TLS access models.
[r229652](http://reviews.llvm.org/rL229652),
[r229654](http://reviews.llvm.org/rL229654).

* A new pass for constructing gc.statepoint sequences with explicit
relocations was added. The pass will be further developed and bugfixed
in-tree. [r229945](http://reviews.llvm.org/rL229945).

* The old x86 vector shuffle lowering code has been removed (the new shuffle
lowering code has been the default for ages and known regressions have been
fixed). [r229964](http://reviews.llvm.org/rL229964).

* A new bitset metadata format and lowering pass has been added. In the
future, this will be used to allow a C++ program to efficiently verify that a
vtable pointer is in the set of valid vtable pointers for the class or its
derived classes. [r230054](http://reviews.llvm.org/rL230054).


## Clang commits

* clang-format gained support for JS type annotations and classes.
[r229700](http://reviews.llvm.org/rL229700),
[r229701](http://reviews.llvm.org/rL229701).

* Most of the InstrProf coverage mapping generation code has been rewritten.
[r229748](http://reviews.llvm.org/rL229748).

* Clang learnt how to analyze FreeBSD kernel printf extensions.
[r229921](http://reviews.llvm.org/rL229921).

* Support has been added to Clang for a form of Control Flow Integrity for
virtual function calls. It verifies the vptr of the correct dynamic type is
being used. [r230055](http://reviews.llvm.org/rL230055).


## Other project commits

* ThreadSanitizer gained support for MIPS64.
[r229972](http://reviews.llvm.org/rL229972).

* lldb now supports process language on Android from lldb-gdbserver.
[r229371](http://reviews.llvm.org/rL229371).

* OpenMP gained a new user-guided lock API.
[r230030](http://reviews.llvm.org/rL230030).