Pull in r292833 from upstream libc++ trunk (by Eric Fiselier):

  Manually force the use of __decltype in C++03 with Clang 3.4.

  <string> uses `decltype` in a way incompatible with `__typeof__`.
  This is problematic when compiling <string> with Clang 3.4 because
  even though it provides `__decltype` libc++ still used `__typeof__`
  because clang 3.4 doesn't provide __is_identifier which libc++
  uses to detect __decltype.

  This patch manually detects Clang 3.4 and properly configures
  for it.

This allows the graphics/openshadinglanguage port to build with
lang/clang34.

PR:		216054

1 files changed, 8 insertions, 1 deletions

diff --git a/contrib/libc++/include/__config b/contrib/libc++/include/__config
index 973f13bc9394..9b9c69f0d134 100644
--- a/contrib/libc++/include/__config
+++ b/contrib/libc++/include/__config
@@ -103,6 +103,9 @@
 
 #if defined(__clang__)
 #define _LIBCPP_COMPILER_CLANG
+# ifndef __apple_build_version__
+#   define _LIBCPP_CLANG_VER (__clang_major__ * 100 + __clang_minor__)
+# endif
 #elif defined(__GNUC__)
 #define _LIBCPP_COMPILER_GCC
 #elif defined(_MSC_VER)
@@ -111,6 +114,10 @@
 #define _LIBCPP_COMPILER_IBM
 #endif
 
+#ifndef _LIBCPP_CLANG_VER
+#define _LIBCPP_CLANG_VER 0
+#endif
+
 // FIXME: ABI detection should be done via compiler builtin macros. This
 // is just a placeholder until Clang implements such macros. For now assume
 // that Windows compilers pretending to be MSVC++ target the microsoft ABI.
@@ -741,7 +748,7 @@ template <unsigned> struct __static_assert_check {};
 
 #ifdef _LIBCPP_HAS_NO_DECLTYPE
 // GCC 4.6 provides __decltype in all standard modes.
-#if !__is_identifier(__decltype) || _GNUC_VER >= 406
+#if !__is_identifier(__decltype) || _LIBCPP_CLANG_VER >= 304 || _GNUC_VER >= 406
 #  define decltype(__x) __decltype(__x)
 #else
 #  define decltype(__x) __typeof__(__x)