1379341 - Prefer homebrew llvm-config to mozbuild llvm-config

Status: RESOLVED FIXED

(Firefox Build System :: General, enhancement)

Description

[Ralph Giles (:rillian)]

We're resolving bug 1368163 by using packaged llvm+clang 4.0.x for local macOS builds. Bug 1310852 added a check for Homebrew's custom location, but it's after the one in the state directory in the search order. This means that anyone who has installed a clang build with `mach artifact toolchain` or through a recent run of `mach boostrap` will get the wrong libclang and hit the C++ parser hang/crash issue.

I think we just need to flip the order of the checks.

Comment 1

[Ralph Giles (:rillian)]

Attachment: Bug 1379341 - Prefer llvm-config from homebrew to mozbuild.

We've had trouble with crashes and hangs on macOS with
libclang builds from tooltool, so for local developer
builds we prefer the homebrew or macports packages
installed by `mach bootstrap`.

However, we were searching ~/.mozbuild before the homebrew
directory, resulting using the wrong libclang when developers
had run `mach bootstrap` before the switch, or anyone who
had used `mach artifact toolchain` on macOS.

Review commit: https://reviewboard.mozilla.org/r/155384/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/155384/

Comment 2

[Gregory Szorc [:gps]]

Comment on attachment 8884485 [details]
Bug 1379341 - Prefer llvm-config from homebrew to mozbuild.

https://reviewboard.mozilla.org/r/155384/#review160480

::: toolkit/moz.configure:626
(Diff revision 1)
>  @imports('os')
>  @imports('subprocess')
>  def llvm_config_paths(host):
>      llvm_config_progs = [
>          'llvm-config-4.0',
> -        'llvm-config-mp-4.0',   # MacPorts's chosen naming scheme
> +        'llvm-config-mp-4.0',   # MacPorts' chosen naming scheme.

Nit: there is no universally agreed upon policy for apostrophe-s after singular nouns, irregardless if the noun is singular or proper. For plural nouns, AFAIK it is universally accepted to omit the apostrophe-s. I would argue "MacPorts" is a singular noun since we don't have multiple "MacPort" (keeping in mind that "Ports" derives from the BSD "Ports" system). So the use of an apostrophe-s here is subjective and the old form was acceptable.

That being said, I live in the USA and recognize that I speak "low English." Since you reside in a Commonwealth nation, I must automatically defer to you on matters concerning proper use of the English language. So I won't prevent you from changing this comment :)

Comment 3

[Ralph Giles (:rillian)]

Ha! You may have a point. I think I just learned a less-sophisticated rule in school. "Low English" often wins on complexity!

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d6c1661d4040
Prefer llvm-config from homebrew to mozbuild. r=gps

Comment 5

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/mozilla-central/rev/d6c1661d4040