On Tue, 11 Feb 2020 15:20:00 +0100 Jeremie Courreges-Anglas <j...@wxcvbn.org> wrote:
> fwiw I'm already ok with the diff George sent for ports/devel/llvm. > I'm mostly ok with this one but it would be nice to know whether > base-clang can rebuild itself. :) base-clang can't rebuild itself in the normal way. I have been exchanging mails with Todd Mortimer, who has been testing my diff with a faster macppc machine. The diff changes the ABI between /usr/bin/clang and /usr/lib/libc++.so.3.0, so when we install a new libc++ built by clang -msvr4-struct-return, but still have a clang built as if by -maix-struct-return, then clang crashes and can't rebuild itself! It might be possible to use a static-link clang to cross the ABI change. A backtrace from clang pointed to a function in libc++ that returns a std::string::iterator, a small struct where sizeof(iterator) == 4. This was not a problem with ports-clang, because we use ports-gcc to build ports-clang; and ports-clang uses libestdc++ (from ports-gcc), not libc++ (from base). Both ports-clang and libestdc++ got built by gcc -msvr4-struct-return. --George
