[llvm-commits] [llvm] r89211 - /llvm/trunk/CMakeLists.txt

[Daniel Dunbar]

On Sun, Nov 22, 2009 at 11:01 AM, Óscar Fuentes <ofv at wanadoo.es> wrote:
> Daniel Dunbar <daniel at zuster.org> writes:
>
>>>> URL: http://llvm.org/viewvc/llvm-project?rev=89211&view=rev
>>>> Log:
>>>> Turn LLVM_BUILD_EXAMPLES off by default in CMake builds, to match Makefiles &
>>>> Clang.
>>>
>>> What's the rationale for this?
>>>
>>> (And wouldn't it warrant the corresponding update of docs/CMake.html,
>>> where default values for variables are listed?)
>>
>> The rationale for changing the default (for cmake and make, I assume
>> we agree they should have the same default) is that most people
>> building LLVM don't care about the examples (because they are
>> developers), and this greatly increases cycle times because of the
>> sheer number of link steps it adds. Having examples be "optional"
>> builds for people exploring LLVM seems reasonable to me, the only
>> value I see in building them regularly is to prevent them from being
>> out-dated, but I will change (one, fast) buildbot to maintain that.
>
> I do not agree with this policy. IMHO making things as straightforward
> as possible for people exploring LLVM is more important than removing
> little annoyances for developers (and having to write
> -DLLVM_BUILD_EXAMPLES=OFF when you configure a fresh checkout is a
> little annoyance). But this is just IMHO.
>
> One compromise that we can easily implement (at least on the cmake
> build) is to default to OFF when building from a svn checkout and ON
> otherwise. What do you think?

I would rather change it in releases, since we already make this
distinction in version tags. And I'm not actually yet convinced it is
even the right default. Imagine we have tons and tons of examples, do
I as a newbie want them all to be built? Probably not, I'd rather get
the build done, and go type make in examples/TheOneThingIAmInterested
in.

 - Daniel