[cfe-dev] Supporting building clang/llvm with VS2012. Why that one?

[David Blaikie]

On Mon, Mar 3, 2014 at 5:44 AM, Dallman, John <john.dallman at siemens.com> wrote:
> G M wrote:
>
>> Any organisation can make any rule it likes, but it's not clear to me, subject to disk
>> space, what reasonable rule would want to prevent someone installing a full Visual Studio
>> and an Express VS version together, or hold both of them back at some old version and
>> allow no other versions if they work fine side by side.
>>
>> If some organisation wanted to do that, it'd seem like that company would be even less
>> likely to experiment with clang at all.
>
> You are radically over-estimating the internal consistency of large organisations. Some of
> them want to have standard configurations for machines, because that sounds good to people
> who make policy, and means it's easy to replace machines that go bad. They are very capable
> of failing to realise that would prevent use of new software, because the people who make
> the policies either don't understand software development - thinking in terms of office
> automation instead - or just fail to join the dots. Fortunately, most of them don't have
> effective enforcement for their policies, so they can be worked around.
>
> Remember, Dilbert is funny because it isn't exaggerated very much.

While all of that is certainly true to some degree - one doesn't have
to be that uninformed to end up in a situation where they're using an
old toolchain. Every compiler upgrade comes with some cost of bug
hunting and source changes to accommodate it - when and how that cost
is justified varies.

So, yes, there are reasonable (and unreasonable but still real)
reasons that people might be running an old toolchain for large
projects.

The (possibly incorrect) assumption in the original post here is that
it was just a matter of what was installed to work on LLVM itself, but
this doesn't account for the fact that many people use LLVM (and Clang
moreso) as a library built into larger projects - the cost involved in
upgrading a compiler means upgrading the whole project to work with
the newer compiler. (and all other engineers working on that project
need to pay that cost - not just those working on the LLVM portions)

In any case, as Chandler said - those working on Windows can best
assess their versioning needs, but it's healthy to reach out and ask
sometimes just to check if we're not stuck in a rut where everyone
assumes everyone else is the limiting factor keeping us back on older
tools.

- David