1254953 - Add moz.build support for building clang plugins

Status: NEW

(Firefox Build System :: General, defect)

Description

[(not currently active) Ted Mielczarek]

We currently build our clang-plugin using a pile of Makefile hacks:
https://hg.mozilla.org/mozilla-central/file/e7319545eb3819da67ffe1d4233022ae71e3a9a1/build/clang-plugin/Makefile.in

I ran into this yesterday as froydnj was hitting problems with it with his libc++ work because his try build was trying to link his prebuild libc++ into there on the taskcluster cross-mac builds, despite the clang plugin actually being built as a host binary (although misnamed as libclangplugin.dylib in the linux->mac cross case).

We should probably just bite the bullet and add some moz.build support to do this in a sensible fashion, like `ClangPlugin(...)`.

Comment 1

[Mike Hommey [:glandium]]

The fundamental problem is that the clang plugin is a host shared library and we have no rules for that. FWIW, I wanted to avoid touching this Makefile until the toolchain mess is fixes, which depends on things like bug 1250301 and bug 1224463.
I'd rather disable the clang plugin on cross-mac builds in the meanwhile.