On 03.09.2011, at 13:58, Blue Swirl wrote: > On Fri, Sep 2, 2011 at 9:47 PM, Anthony Liguori <aligu...@us.ibm.com> wrote: >> Hi, >> >> There have been a few attempts in the past to allow TCG to be disabled >> at build time. Recently, Alex made the suggestion that we could do it by >> using >> the same trick that we used to introduce kvm support. That involves >> introducing >> a tcg_enabled() macro that will be (0) if TCG is disabled in the build. >> >> GCC is smart enough to do dead code elimination if it sees an if (0) and the >> result is that if you can do: > > Is this also true for gcc optimization -O0? Didn't we have breakages > because of similar issues recently?
We obviously need to provide stubs for code that doesn't get compiled with --disable-tcg, but we do the same for KVM and Xen today. I agree though that we should have a buildbot running a build with -O0 (--enable-debug) to make sure nothing slips through. Alex