CROSS_TOOLCHAIN=amd64-gcc fails to build after clang 3.6.0 import

[Mark Millard]

I'd sent out a note Saturday for this for powerpc64-xtoolchain-gcc and its powerpc64-gcc port: use of CROSS_TOOLCHAIN=powerpc64-gcc used on a powerpc64. No solution, just notes about what was going on after looking at the source code related to the messages. If you care, see:

> CROSS_TOOLCHAIN=powerpc64-gcc mishandles "Substitution Failure Is Not An Error" when compiling clang and stops the build

( https://lists.freebsd.org/pipermail/freebsd-toolchain/2015-March/001506.html )



> sizeof(__is_convertible_imp::__test<_T2>(__is_convertible_imp::__source<_T1>()))
>      == 1


is the core place involved in your example and mine but the order of compilation for my context means a different starting place that ended up using the above.

lang/gcc5 did the same when I later tried it.

I doubt that host-type or TARGET or TARGET_ARCH matter. I doubt xtoolchain vs. normal port matters. I expect that the issue spans a range of g++ versions.

Unfortunately that probably also means that the effectively "Substitution Failure of this kind Is An Error" rule now in use will probably be around for a while: it is likely not some local accident that has a quick fix. The best case is if it is simple but each version/variant needs to release with the change.


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Mark Millard
markmi at dsl-only.net