Add the AArch64 llvm backend

[dim]

Summary

This adds the AArch64 llvm backend to the build to allow for early testing
and to ease any rework of how clang is built to take arm64 in to account.

[emaste]

lib/clang/include/AArch64GenAsmMatcher.inc

1 ↗

(On Diff #3016)

Please unexpand these before checkin.

SVN does the expansion on checkout. I'm not sure if they're collapsed on checkin, or stored verbatim, but don't want to find out :-)

[dim]

Are we sure we already want to hook this up to the build by default? There were already a few complaints about building non-default arches...

Also, the other usr.bin/clang tools should be updated, otherwise they won't link. Those are the ones that are enabled via WITH_CLANG_EXTRAS.

I'll see if I can fix that up, but not now, I need to get some sleep first...

[dim]

lib/clang/clang.build.mk

33 ↗

(On Diff #3016)

That should not be "arm53", but "arm64", obviously.

[andrew]

We will also need llvm r222292 to build the kernel without using floating point registers.

[emaste]

In D1446#10, @andrew wrote:

We will also need llvm r222292 to build the kernel without using floating point registers.

Can we bring this one directly into HEAD?

[andrew]

In D1446#11, @emaste wrote:

Can we bring this one directly into HEAD?

I don't see why not, it's a simple change. http://llvm.org/viewvc/llvm-project/?view=revision&revision=222292

[dim]

• Unexpanded $FreeBSD$ keywords
• Added aarch64 libraries to both the WITH_CLANG_EXTRAS programs and lldb
• For some Makefiles, made the library order mostly the same as an upstream autoconf-based build.

I tested this by building clang with the default settings, and also with WITH_CLANG_EXTRAS and WITH_LLDB set.

[emaste]

I imported this change then merged to my arm64 branch and it looks fine to me.

[andrew]

I successfully built a toolchain in my arm64 tree with this change.

[dim]

Closed by commit rS276783 (authored by @dim).