[CMake] Support compiler-rt builtins library in tests

We're building tests with -nostdlib which means that we need to
explicitly include the builtins library. When using libgcc (default)
we can simply include -lgcc_s on the link line, but when using
compiler-rt builtins we need a complete path to the builtins library.

This path is already available in CMake as <PROJECT>_BUILTINS_LIBRARY,
so we just need to pass that path to lit and if config.compiler_rt is
true, link it to the test.

Prior to this patch, running tests when compiler-rt is being used as
the builtins library was broken as all tests would fail to link, but
with this change running tests when compiler-rt bultins library is
being used should be supported.

Differential Revision: https://reviews.llvm.org/D56701

llvm-svn: 353208

1 files changed, 8 insertions, 0 deletions

diff --git a/libcxx/docs/TestingLibcxx.rst b/libcxx/docs/TestingLibcxx.rst
index ebbbf628ac0..d8060fed1f1 100644
--- a/libcxx/docs/TestingLibcxx.rst
+++ b/libcxx/docs/TestingLibcxx.rst
@@ -183,6 +183,14 @@ configuration. Passing the option on the command line will override the default.
   option is specified or the environment variable LIBCXX_COLOR_DIAGNOSTICS is
   present then color diagnostics will be enabled.
 
+.. option:: llvm_unwinder
+
+  Enable the use of LLVM unwinder instead of libgcc.
+
+.. option:: builtins_library
+
+  Path to the builtins library to use instead of libgcc.
+
 
 Environment Variables
 ---------------------