[llvm] r298127 - LTO: Work around libstdc++ version mismatch bug, see D31063 review thread.

[Davide Italiano via llvm-commits]

On Fri, Mar 17, 2017 at 2:49 PM, Peter Collingbourne via llvm-commits
<llvm-commits at lists.llvm.org> wrote:
> Author: pcc
> Date: Fri Mar 17 16:49:09 2017
> New Revision: 298127
>
> URL: http://llvm.org/viewvc/llvm-project?rev=298127&view=rev
> Log:
> LTO: Work around libstdc++ version mismatch bug, see D31063 review thread.
>
> Modified:
>     llvm/trunk/lib/LTO/Caching.cpp
>
> Modified: llvm/trunk/lib/LTO/Caching.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/LTO/Caching.cpp?rev=298127&r1=298126&r2=298127&view=diff
> ==============================================================================
> --- llvm/trunk/lib/LTO/Caching.cpp (original)
> +++ llvm/trunk/lib/LTO/Caching.cpp Fri Mar 17 16:49:09 2017
> @@ -37,7 +37,10 @@ Expected<NativeObjectCache> lto::localCa
>        return AddStreamFn();
>      }
>
> -    if (MBOrErr.getError() != std::errc::no_such_file_or_directory)
> +    // FIXME: Workaround for libstdc++ version mismatch bug, see D31063 review
> +    // thread.
> +    if ((std::errc)MBOrErr.getError().value() !=
> +        std::errc::no_such_file_or_directory)
>        report_fatal_error(Twine("Failed to open cache file ") + EntryPath +
>                           ": " + MBOrErr.getError().message() + "\n");
>

As at some point we might decide to move away from Phabricator, or
just because links are transient by their own nature, may I ask you to
write the whole story here? Maybe I'm just overcautious, but in the
past I've more than once stumbled upon `FIXME: see rdar`(I know it's
not the same here as the information is currently accessible, but
still).

-- 
Davide

"There are no solved problems; there are only problems that are more
or less solved" -- Henri Poincare