[llvm] r320737 - Fix isPodLike for MSVC and use it in TypeHashing.

[Zachary Turner via llvm-commits]

Author: zturner
Date: Thu Dec 14 11:41:28 2017
New Revision: 320737

URL: http://llvm.org/viewvc/llvm-project?rev=320737&view=rev
Log:
Fix isPodLike for MSVC and use it in TypeHashing.

This should be a better check than using is_trivially_copyable
behind an #ifdef _MSC_VER.

Modified:
    llvm/trunk/include/llvm/DebugInfo/CodeView/TypeHashing.h
    llvm/trunk/include/llvm/Support/type_traits.h

Modified: llvm/trunk/include/llvm/DebugInfo/CodeView/TypeHashing.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/DebugInfo/CodeView/TypeHashing.h?rev=320737&r1=320736&r2=320737&view=diff
==============================================================================
--- llvm/trunk/include/llvm/DebugInfo/CodeView/TypeHashing.h (original)
+++ llvm/trunk/include/llvm/DebugInfo/CodeView/TypeHashing.h Thu Dec 14 11:41:28 2017
@@ -132,15 +132,10 @@ struct GloballyHashedType {
     return Hashes;
   }
 };
-#if defined(_MSC_VER)
-// is_trivially_copyable is not available in older versions of libc++, but it is
-// available in all supported versions of MSVC, so at least this gives us some
-// coverage.
-static_assert(std::is_trivially_copyable<GloballyHashedType>::value,
+static_assert(isPodLike<GloballyHashedType>::value,
               "GloballyHashedType must be trivially copyable so that we can "
               "reinterpret_cast arrays of hash data to arrays of "
               "GloballyHashedType");
-#endif
 } // namespace codeview
 
 template <> struct DenseMapInfo<codeview::LocallyHashedType> {

Modified: llvm/trunk/include/llvm/Support/type_traits.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/type_traits.h?rev=320737&r1=320736&r2=320737&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/type_traits.h (original)
+++ llvm/trunk/include/llvm/Support/type_traits.h Thu Dec 14 11:41:28 2017
@@ -30,9 +30,9 @@ namespace llvm {
 template <typename T>
 struct isPodLike {
   // std::is_trivially_copyable is available in libc++ with clang, libstdc++
-  // that comes with GCC 5.
+  // that comes with GCC 5, and MSVC.
 #if (__has_feature(is_trivially_copyable) && defined(_LIBCPP_VERSION)) ||      \
-    (defined(__GNUC__) && __GNUC__ >= 5)
+    (defined(__GNUC__) && __GNUC__ >= 5) || defined(_MSC_VER)
   // If the compiler supports the is_trivially_copyable trait use it, as it
   // matches the definition of isPodLike closely.
   static const bool value = std::is_trivially_copyable<T>::value;