[llvm-dev] Please dogfood LLD

[Renato Golin via llvm-dev]

On 19 March 2017 at 01:06, Sean Silva via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
> This seems to have caused some bad publicity:
> https://www.reddit.com/r/programming/comments/601kn9/trying_out_llvm_40s_lld_linker/
> One user even comes away with this impression: "As you can see in the link,
> LLD is unable to link several projects. It's far from production ready."
> (and I cannot blame them; LLD should "Just Work" with almost all major
> open-source software packages, and failing 3, including a very common one
> like libjpeg-turbo which is used by firefox and chromium, doesn't reflect
> well)

Hi Sean,

You can't avoid bad publicity, even if you do everything right. It
took Rui almost a year more than it took me to think LLD was good
enough for wider use, and it still wasn't.

Do you know why? Because it never will.

Toolchain development is a curse as much as it's an bless. You can do
some amazing software and still be caught with your pants down on
really simple cases. Different than almost every other software
technology on the planet (modulo kernel), toolchains have to cope with
a problem space that is so random, unpredictable and crazy, that it's
literally impossible to compile every software on the planet. It just
is.

However, most non-toolchain / non-kernel developers will look at their
new shiny tool, which claims "production use" and will think: "Oh,
this *must* work on all the crazy things I've done in the past". Most
of us know this is non-sense and we shouldn't be deterred by comments
like this. They're noise, not signal.

The Phoronix article hints at something inspiring: All workloads were
faster, and some were significantly faster. "Can't compile", as we
know, can be a simple bug, user error, unsupported GNU extensions,
lack of tests on that specific platform, etc. They should be fixed,
yes, but they're not a reflection of your work, let alone "the only"
reflection.

Maybe one lesson we can learn from this is: don't use the words
"production ready", but instead "user beta testing". It worked very
well for Google for the past 10 years and can work for us, too. :)


> One user experiencing a segfault appears to have been kind enough to send us
> a bug report: https://bugs.llvm.org/show_bug.cgi?id=32341

Most users are nice. So far, there was only one negative comment...
Noise, in my view.

The LLD developers are, in my view, doing an amazing job. Please,
don't be affected by noise.

cheers,
--renato