Fix PR38160 - init_priority attribute not supported by GCC on Apple.

This patch guards the use of __attribute__((init_priority(101)))
within memory_resource.cpp when building with compilers that don't
support it. Specifically GCC on Apple platforms, and MSVC.

llvm-svn: 337205

diff --git a/libcxx/src/experimental/memory_resource.cpp b/libcxx/src/experimental/memory_resource.cpp
index a6eca37..a3b64cc 100644 (file)
--- a/libcxx/src/experimental/memory_resource.cpp
+++ b/libcxx/src/experimental/memory_resource.cpp
@@ -68,12 +68,23 @@ union ResourceInitHelper {
   _LIBCPP_CONSTEXPR_AFTER_CXX11 ResourceInitHelper() : resources() {}
   ~ResourceInitHelper() {}
 };
+
+// Detect if the init_priority attribute is supported.
+#if (defined(_LIBCPP_COMPILER_GCC) && defined(__APPLE__)) \
+  || defined(_LIBCPP_COMPILER_MSVC)
+// GCC on Apple doesn't support the init priority attribute,
+// and MSVC doesn't support any GCC attributes.
+# define _LIBCPP_INIT_PRIORITY_MAX
+#else
+# define _LIBCPP_INIT_PRIORITY_MAX __attribute__((init_priority(101)))
+#endif
+
 // When compiled in C++14 this initialization should be a constant expression.
 // Only in C++11 is "init_priority" needed to ensure initialization order.
 #if _LIBCPP_STD_VER > 11
 _LIBCPP_SAFE_STATIC
 #endif
-ResourceInitHelper res_init  __attribute__((init_priority (101)));
+ResourceInitHelper res_init _LIBCPP_INIT_PRIORITY_MAX;
 
 } // end namespace