[libcxxabi] Refactor building and testing libc++abi without threads

Summary:
This patch adds CMake support for building and testing libc++abi without threads. 


1. Add `LIBCXXABI_ENABLE_THREADS` option to CMake.
2. Propagate `LIBCXXABI_ENABLE_THREADS` to lit via lit.site.cfg.in
3. Configure tests for `LIBCXXABI_ENABLE_THREADS=OFF

Currently the test suite does not work when libc++abi is built without threads because that information does not propagate to the test suite.



Reviewers: danalbert, mclow.lists, jroelofs

Reviewed By: jroelofs

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D6393

llvm-svn: 222702

1 files changed, 8 insertions, 0 deletions

diff --git a/libcxxabi/test/test_guard.cpp b/libcxxabi/test/test_guard.cpp
index 96af56a7be1..41ff79432b5 100644
--- a/libcxxabi/test/test_guard.cpp
+++ b/libcxxabi/test/test_guard.cpp
@@ -7,10 +7,14 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "../src/config.h"
 #include "cxxabi.h"
 
 #include <cassert>
+
+#if !LIBCXXABI_HAS_NO_THREADS
 #include <thread>
+#endif
 
 // Ensure that we initialize each variable once and only once.
 namespace test1 {
@@ -72,6 +76,7 @@ namespace test3 {
     }
 }
 
+#if !LIBCXXABI_HAS_NO_THREADS
 // A simple thread test of two threads racing to initialize a variable. This
 // isn't guaranteed to catch any particular threading problems.
 namespace test4 {
@@ -123,12 +128,15 @@ namespace test5 {
         assert(run_count == 1);
     }
 }
+#endif /* LIBCXXABI_HAS_NO_THREADS */
 
 int main()
 {
     test1::test();
     test2::test();
     test3::test();
+#if !LIBCXXABI_HAS_NO_THREADS
     test4::test();
     test5::test();
+#endif
 }