tree ed3c23559292bc3ff6807f8c2a1e64a6819c1ba7
parent 06963322c77ae86b5a43f02e67e2be6c494826b5
author Louis Dionne <ldionne@apple.com> 1591730053 -0400
committer Copybara-Service <copybara-worker@google.com> 1598638622 -0700

[NFCI] Clean up exceptions related CMake and Lit options in libc++abi and libunwind

First, libc++abi doesn't need to add the no-exceptions Lit feature itself,
since that is already done in the config.py for libc++, which it reuses.
Specifically, config.enable_exceptions is set based on @LIBCXXABI_ENABLE_EXCEPTIONS@
in libc++abi's lit.cfg.in, and libc++'s config.py handles that correctly.

Secondly, libunwind's LIBUNWIND_ENABLE_EXCEPTIONS is never set (it's
probably a remnant of copy-pasting code between the runtime libraries),
so the library is always built with exceptions disabled (which makes
sense since it implements the runtime support for exceptions).
Conversely, the test suite is always run with exceptions enabled
(not sure why), but that is preserved by the default behavior of
libc++'s config.py.

GitOrigin-RevId: 0e04342ae0399876f3488464d12f5a4da5085456