Extend the "__is_pod" hack, which demotes various type trait keywords

(__is_pod, __is_signed, etc.) to normal identifiers if they are
encountered in certain places in the grammar where we know that prior
versions of libstdc++ or libc++ use them, to still allow the use of
these keywords as type traits. Fixes <rdar://problem/9836262> and PR10184.

llvm-svn: 162937

1 files changed, 10 insertions, 2 deletions

diff --git a/clang/test/SemaCXX/libstdcxx_is_pod_hack.cpp b/clang/test/SemaCXX/libstdcxx_is_pod_hack.cpp
index 3ac233627cc..1ba3721c8c2 100644
--- a/clang/test/SemaCXX/libstdcxx_is_pod_hack.cpp
+++ b/clang/test/SemaCXX/libstdcxx_is_pod_hack.cpp
@@ -8,6 +8,7 @@
 
 template<typename T>
 struct __is_pod {
+  __is_pod() {}
 };
 
 __is_pod<int> ipi;
@@ -28,6 +29,13 @@ struct test_is_signed {
 
 bool check_signed = test_is_signed::__is_signed;
 
-#if __has_feature(is_pod)
-#  error __is_pod won't work now anyway
+template<bool B> struct must_be_true {};
+template<> struct must_be_true<false>;
+
+void foo() {
+  bool b = __is_pod(int);
+  must_be_true<__is_pod(int)> mbt;
+}
+#if !__has_feature(is_pod)
+#  error __is_pod should still be available.
 #endif