Introduce an egregious hack to fix PR4828.

The problem this change addresses is that we treat __is_pod and
__is_empty as keywords in C++, because they are built-in type traits
in GCC >= 4.3. However, GNU libstdc++ 4.2 (and possibly earlier
versions) define implementation-detail struct templates named __is_pod
and __is_empty. 

This commit solves the problem by recognizing

  struct __is_pod

and

  struct __is_empty

as special token sequences. When one of these token sequences is
encountered, the keyword (__is_pod or __is_empty) is implicitly
downgraded to an identifier so that parsing can continue. This is an
egregious hack, but it has the virtue of "just working" whether
someone is using libstdc++ 4.2 or not, without the need for special
flags.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@80988 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 0 deletions

diff --git a/test/SemaCXX/libstdcxx_is_pod_hack.cpp b/test/SemaCXX/libstdcxx_is_pod_hack.cpp
new file mode 100644
index 0000000000..df064bc6a0
--- /dev/null
+++ b/test/SemaCXX/libstdcxx_is_pod_hack.cpp
@@ -0,0 +1,7 @@
+// RUN: clang-cc -fsyntax-only %s
+
+template<typename T>
+struct __is_pod {
+};
+
+__is_pod<int> ipi;