[cfe-commits] r164992 - /cfe/trunk/Makefile

[David Blaikie]

On Tue, Oct 2, 2012 at 11:39 AM, Bill Wendling <isanbard at gmail.com> wrote:
> On Oct 2, 2012, at 11:35 AM, David Blaikie <dblaikie at gmail.com> wrote:
>
>> On Mon, Oct 1, 2012 at 11:19 PM, Bill Wendling <isanbard at gmail.com> wrote:
>>> Author: void
>>> Date: Tue Oct  2 01:19:15 2012
>>> New Revision: 164992
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=164992&view=rev
>>> Log:
>>> Use an environment variable instead of what's in the make cmd goals.
>>
>> Still makes me sad that this is an environment variable (admittedly
>> this isn't important - just an aesthetic issue for me)
>
> I know. I tried to make it work, but couldn't. The thing is that clang is built with MAKECMDGOALS == all, and not 'clang-only', which I would prefer.

Where's that MAKECMDGOALS value coming from? just the LLVM build
invoking the Clang build?

> So I had to default to making it a variable. :-(
>
>> - what's the
>> use case for this? It just seems like this should naturally fall out
>> from any build command that wants to just build clang. If it doesn't
>> then someone may get sub-optimal builds because they don't know about
>> this environment variable they need to use.
>
> This is for building clang with LTO and wanting only the clang and clang++ executables and libraries (no tools, etc.). The problem here is that LTO takes a *long* time to link things because of how much memory it takes. Building anything extraneous is a waste here.

Yeah, I figured it was something like that - my point was that while
it's a big waste for this case, it's a small waste for every other
user that wants to just build the Clang installation binaries &
doesn't use this flag.

> What I did is link this environment variable with the 'clang-only' flag (see equivalent patch on llvm-commits). When someone specifies 'make clang-only', they won't get the other stuff.

Hmm, OK - I'm not quite sure how that works just looking at the LLVM
Makefile, but I'll keep an eye out for the patch as I work through my
email backlog. If it does the right thing for any LLVM make target
then I can't complain too much - just a minor implementation wart at
that point.

- David