tree 5b16fcfeeae450cdac2a302973b191c277116828
parent c309ed0d203302e58cb52e46c53a6fc675a9b934
author Martin Storsjö <martin@martin.st> 1635027080 +0300
committer Copybara-Service <copybara-worker@google.com> 1637097087 -0800

[runtimes] Fix building initial libunwind+libcxxabi+libcxx with compiler implied -lunwind

This does mostly the same as D112126, but for the runtimes cmake files.
Most of that is straightforward, but the interdependency between
libcxx and libunwind is tricky:

Libunwind is built at the same time as libcxx, but libunwind is not
installed yet. LIBCXXABI_USE_LLVM_UNWINDER makes libcxx link directly
against the just-built libunwind, but the compiler implicit -lunwind
isn't found. This patch avoids that by adding --unwindlib=none if
supported, if we are going to link explicitly against a newly built
unwinder anyway.

Differential Revision: https://reviews.llvm.org/D113253

GitOrigin-RevId: 7c3d19ab7bcb79636bd65ee55a0fefef224fcb25