LLVM-5.0

[ken@…]

For some reason this doesn't seem to be showing up in the currency check. Announcement at ​http://lists.llvm.org/pipermail/llvm-announce/2017-September/000075.html and downloads are at ​http://releases.llvm.org/download.html#5.0.0

I was going to say "a word to the wise", but I think "a word to the foolish" might be more appropriate (as in "trying to build modern software from source is foolish and will cause you pain") - firefox-56 (due later this month) is trying to move to 'stylo' (new CSS code). That has problems (can't use system nspr or pixman, it can't find the headers ]​https://bugzilla.mozilla.org/show_bug.cgi?id=1341234] - comment 10 seems particularly appropriate), but if those are fixed, or else when stylo is no longer optional, clang will be required for firefox (one of the cargo files needs it).

In circumstances where stylo is enabled, LLVM-4.0.1 is fine - whether or not LLVM-5 will work remains to be determined.

[bdubbs@…]

The reason that the currency scripts didn't find the change was that we had two versions of llvm (3 and 4) in the book at one time. The scripts are not robust enough to handle the situation when llvm3 was removed from the book.

It's fixed now and should be OK as long as we don't have two separate versions of llvm in the book.

[ken@…]

Doing preliminary testing of llvm5 to see how firefox-56 will react, but mesa-17.1.8 fails to build for amd and fixing llvm-5 is not on the list of changes for 17.1.9. There was a patch in May from an intel dev for a similar error, but in (I think) swrast which still applies but didn't fix my problem. Mesa-17.2.0 does build, but that is still development until 17.2.1 comes out.

[ken@…]

Trying firefox-56.0b13, it still fails to build with system nspr and pixman unless stylo is disabled (I assume we and all the other distros will disable stylo for the moment when 56.0 is released), but if system nspr and pixman are not enforced, llvm-5.0 manages to build it.

TL;DR - this needs a 17.2 version of mesa, and people who build firefox might want to build clang ( Compiler RT is apparently not needed ), depending on how long they plan to keep that system.

[Pierre Labastie]

release notes at ​http://releases.llvm.org/5.0.0/docs/ReleaseNotes.html.

3 packages recommend llvm and should be tested:

• potrace
• mesa (see above. mesa-17.2.1 is out)
• gst-plugins-bad

[ken@…]

I built potrace on the system where LLVM-5.0 is installed, it found clang and used it.

I also built gst-plugins-bad, but not with all the dependencies - I didn't use any verbosity so the build only says CC some_filename.lo etc. No mention of llvm or clang in the configure output.

[Pierre Labastie]

Fixed at r19289