On Wed, 24 Oct 2018 at 16:23, Jonathan Wakely wrote: > > On Wed, 24 Oct 2018 at 16:05, Dennis Clarke wrote: > > So the mess seems to be that one must have these include-fixed headers > > in place OR not. > > As I said earlier, when libstdc++ is built it looks at the target > headers and checks which features are present in the libc headers. It > then assumes that doesn't change. If the host machine's headers change > significantly, that can invalidate the configuration that libstdc++ > decided on at build time. > > Due to the significant changes to the libc <math.h> as part of patch > 119966-02, I expect you cannot take a libstdc++ built on an unpatched > system and run it on a patched system. > > > Rainer should be able to confirm it, but I think this is related to > https://gcc.gnu.org/ml/gcc-patches/2016-11/msg00330.html -- that patch Ah yes, Rainer said there: "They were introduced in Solaris 10 Patch 11996[67]-02" > is present in all versions of GCC 7 and 8, so if you're seeing > problems with those versions then I suspect it's due to differences > between <math.h> when libstdc++ was configured and when you're trying > to use it. > > What's not clear from your email is whether you built those versions > of GCC on the host machines where you're testing them (and if so, > whether it was before or after installing patch 119966-02) or whether > you built them on one machine and then copied them to the other hosts.
