[PATCH] [libcxx] Allow the use of ccache when running the test suite.

[Eric Fiselier]

In http://reviews.llvm.org/D6647#101319, @jroelofs wrote:

> If the compiler changes on every iteration of the buildbot, how will ccache make that faster?


The compiler doesn't change every iteration for the most part. On my buildbots I try and update the compiler once a week or so.

In http://reviews.llvm.org/D6647#101319, @jroelofs wrote:

> Also, ccache makes me a bit uncomfortable in a buildbot kind of environment. It's great for development, but it definitely adds one more area for build hysteresis. Perhaps we ought to have nightly (or whatever appropriate frequency) clean builds in addition to such a ccache bot.


Very good point. As I understand it, this should only matter when the compiler changes. I'll make sure to clear the cache entirely when updating the compilers.

In http://reviews.llvm.org/D6647#101645, @danalbert wrote:

> Couldn't you just set cxx_under_test to 'ccache clang++' and be done with it?


As it currently stands that wouldn't work. cxx_under_test is expected to be a single token.

I understand concerns about this setup being fragile. However I would still like to try it out on my bots for the time being. There are a number of extra configurations I would like to run and currently I don't have the resources to do it. My OSX builder takes 30-45 minutes per run. It would be nice to get this down.


http://reviews.llvm.org/D6647

EMAIL PREFERENCES
  http://reviews.llvm.org/settings/panel/emailpreferences/