[macports-ports] branch master updated: ffmpeg: force gcc6 on PPC

Ken Cunningham ken.cunningham.webuse at gmail.com
Sat Oct 21 06:43:10 UTC 2017

> The issue in doing that is that C++ ports will possibly be build inconsistently because macports-gcc6 will use the MacPorts-provided runtimes from libgcc which are not compatible with the host's libstdc++ (used by gcc42).
> If you want to use gcc6 for a full build of MacPorts on ppc, I'd suggest doing something similar to the bootstrapping I documented for modern clang/libc++ on Leopard and Snow Leopard (and please document it for future users).


For c++, you therefore still need to use the cxx11 1.1 PortGroup to get this magic flag for libgcc that makes all the new builds compatible with the old ABI:

configure.cxxflags-append -D_GLIBCXX_USE_CXX11_ABI=0

Alternatively, it would be possible (and preferred, I think) to build libgcc to default always to the old ABI on these systems by adding this flag to the libgcc build:

configure.args-append --with-default-libstdcxx-abi=gcc4-compatible

which we should probably do on 10.4 to 10.8 that are using this method for c++11.


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