mplement __has_unique_object_representations

A helper builtin to facilitate implementing the
std::has_unique_object_representations type trait.

Requested here: https://bugs.llvm.org/show_bug.cgi?id=34942
Also already exists in GCC and MSVC.

Differential Revision: https://reviews.llvm.org/D39064

llvm-svn: 316518

1 files changed, 3 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 7f5b792e8c4..1ed714f8c86 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -4175,6 +4175,7 @@ static bool CheckUnaryTypeTraitTypeCompleteness(Sema &S, TypeTrait UTT,
   case UTT_IsDestructible:
   case UTT_IsNothrowDestructible:
   case UTT_IsTriviallyDestructible:
+  case UTT_HasUniqueObjectRepresentations:
     if (ArgTy->isIncompleteArrayType() || ArgTy->isVoidType())
       return true;
 
@@ -4614,6 +4615,8 @@ static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT,
     //   Returns True if and only if T is a complete type at the point of the
     //   function call.
     return !T->isIncompleteType();
+  case UTT_HasUniqueObjectRepresentations:
+    return T.hasUniqueObjectRepresentations(C);
   }
 }