[llvm-dev] [cfe-dev] Fwd: Raising CMake minimum version to 3.4.3

[Bruce Hoult via llvm-dev]

Probably no one cares, but add to those, machines at home:

- i7 6700k, ubuntu 14.04: bootstrap 0m32s, make 0m35s
- Raspberry Pi 2 (4x A7 @900 MHz), Raspbian: bootstrap 9m40s, make 20m41s

Interesting that the Pi 3 only gains 25% - 30% over the Pi 2, whereas the
newer i7 is double the speed of the 2012 one.

On Thu, Apr 28, 2016 at 12:42 AM, Bruce Hoult <bruce at hoult.org> wrote:

> cmake is a big dependency, but it doesn't seem to have many dependencies
> itself. They say it's just a C++ compiler and a make (not necessarily gnu).
> Probably there are one or two more than that :-)  A shell, for a start; git
> or tar/gzip etc.
>
> The current *nix source tarball is 6.4 MB gzipped. Just for fun I grabbed
> it and tried building on four machines:
>
> - 3.4 GHz i7 3770 with Ubuntu 14.04
> - 2.2 GHz 2011 i7 MacBook Pro with Yosemite
> - Odroid XU4 with Ubuntu Mate 15.10 (Exynos5422 4x A15 @2GHz, 4x A7 @1.4
> GHz)
> - Raspberry Pi 3 with Raspbian (4x A53 @1.2 GHz)
>
> I used --parallel=4 on the Pi, 8 on the others
>
> ./bootstrap
> - 1m10s linux
> - 2m05s mbp
> - 3m18s xu4
> - 7m28s pi3
>
> make
> - 1m07s linux
> - 1m18s mbp
> - 5m14s xu4
> - 16m31s Pi3
>
>
> On Wed, Apr 27, 2016 at 10:08 AM, Renato Golin via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>> We can't assume every Linux is Ubuntu, nor that every platform has
>> packages for this or that release.
>>
>> You are asking for a move to built CMake support, from packages, and
>> that's a big move. We can't control CMake's progress nor its repository.
>>
>> This is bigger than a simple version upgrade, regardless of which version
>> the new Ubuntu or freebsd ships, or the fact that other systems already
>> need to build it.
>>
>> Cheers,
>> Renato
>> On 26 Apr 2016 11:33 p.m., "Chris Bieneman via cfe-dev" <
>> cfe-dev at lists.llvm.org> wrote:
>>
>>> Actually forward to LLVM-dev because I obviously don’t know how email
>>> works…
>>>
>>> -Chris
>>>
>>> Begin forwarded message:
>>>
>>> *From: *Chris Bieneman via cfe-dev <cfe-dev at lists.llvm.org>
>>> *Subject: **[cfe-dev] Raising CMake minimum version to 3.4.3*
>>> *Date: *April 26, 2016 at 3:01:23 PM PDT
>>> *To: *cfe-dev <cfe-dev at lists.llvm.org>, llvm-dev at lists.apple.com
>>> *Cc: *Galina Kistanova <gkistanova at gmail.com>
>>> *Reply-To: *Chris Bieneman <beanz at apple.com>
>>>
>>> Hello llvm-dev and cfe-dev,
>>>
>>> I want open up the discussion of upgrading our minimum required CMake
>>> version.
>>>
>>> In the past when we’ve discussed this one of the major reasons for not
>>> moving forward was that the Ubuntu LTS release was on CMake 2.8.12.x. A few
>>> days ago Ubuntu 16.04, the new LTS, was released, and it contains CMake
>>> 3.5.1.
>>>
>>> I have a couple of motivations for this, the biggest of which is that
>>> I’ve hit a wall trying to overcome some limitations in the CMake
>>> ExternalProject module which I can’t get past without being on CMake 3.4 or
>>> newer. These limitations make using ExternalProject to build the LLVM
>>> test-suite and runtime libraries (compiler-rt, libcxx, etc) difficult.
>>>
>>> The other big motivation that I have for this is the ability to cleanup
>>> code. We have a lot of CMake code that checks CMAKE_VERSION and enables and
>>> disables features used on the version. None of the places where we
>>> currently have CMAKE_VERSION checks should impact build correctness, but
>>> most people don’t realize that if you’re using Ninja your build will be
>>> faster on a newer CMake than on an older one. It would be nice if we just
>>> pushed the bar up and could remove a bunch of those conditionals.
>>>
>>> To do this we need bot maintainers to update their CMake installations,
>>> so we need some consensus that (1) we want to do this and (2) what a
>>> reasonable timeline for doing it is.
>>>
>>> What I’d like to do is raise the minimum version for all LLVM projects
>>> to CMake 3.4.3 at the end of May. Setting the date at the end of May gives
>>> bot maintainers and developers lots of time to update, and CMake 3.4.3 is
>>> the last CMake 3.4 release and it is widely available. For reference here’s
>>> a list of linux distributions and their CMake versions:
>>>
>>> Ubuntu Wily -> 3.2.2
>>> Ubuntu Xenial -> 3.5.1
>>> Ubuntu Yakkety -> 3.5.1
>>> Debian jessie -> 3.0.2
>>> Debian stretch -> 3.5.1
>>> Debian sid -> 3.5.2
>>> FreeBSD 10.2 -> 3.5.0
>>> FreeBSD HEAD -> 3.5.2
>>>
>>> Feedback?
>>>
>>> Thanks,
>>> -Chris
>>> _______________________________________________
>>> cfe-dev mailing list
>>> cfe-dev at lists.llvm.org
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
>>>
>>>
>>>
>>> _______________________________________________
>>> cfe-dev mailing list
>>> cfe-dev at lists.llvm.org
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
>>>
>>>
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>
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