3 files changed, 25 insertions, 1 deletions
diff --git a/lib/Sema/AttributeList.cpp b/lib/Sema/AttributeList.cpp
index 77d962542b..c3efda9a7a 100644
--- a/lib/Sema/AttributeList.cpp
+++ b/lib/Sema/AttributeList.cpp
@@ -85,6 +85,7 @@ AttributeList::Kind AttributeList::getKind(const IdentifierInfo *Name) {
     .Case("deprecated", AT_deprecated)
     .Case("visibility", AT_visibility)
     .Case("destructor", AT_destructor)
+    .Case("forbid_temporaries", AT_forbid_temporaries)
     .Case("format_arg", AT_format_arg)
     .Case("gnu_inline", AT_gnu_inline)
     .Case("weak_import", AT_weak_import)
diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index 474c7cb82f..21d0f46528 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -885,6 +885,24 @@ static void HandleVecReturnAttr(Decl *d, const AttributeList &Attr,
   d->addAttr(::new (S.Context) VecReturnAttr(Attr.getLoc(), S.Context));
 }
 
+static void HandleForbidTemporariesAttr(Decl *d, const AttributeList &Attr,
+                                        Sema &S) {
+  assert(Attr.isInvalid() == false);
+
+  if (Attr.getNumArgs() != 0) {
+    S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 0;
+    return;
+  }
+
+  if (!isa<TypeDecl>(d)) {
+    S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
+      << Attr.getName() << 9 /*class*/;
+    return;
+  }
+
+  d->addAttr(::new (S.Context) ForbidTemporariesAttr(Attr.getLoc(), S.Context));
+}
+
 static void HandleDependencyAttr(Decl *d, const AttributeList &Attr, Sema &S) {
   if (!isFunctionOrMethod(d) && !isa<ParmVarDecl>(d)) {
     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_decl_type)
@@ -2674,6 +2692,8 @@ static void ProcessInheritableDeclAttr(Scope *scope, Decl *D,
   case AttributeList::AT_ext_vector_type:
     HandleExtVectorTypeAttr(scope, D, Attr, S);
     break;
+  case AttributeList::AT_forbid_temporaries:
+    HandleForbidTemporariesAttr(D, Attr, S); break;
   case AttributeList::AT_format:      HandleFormatAttr      (D, Attr, S); break;
   case AttributeList::AT_format_arg:  HandleFormatArgAttr   (D, Attr, S); break;
   case AttributeList::AT_global:      HandleGlobalAttr      (D, Attr, S); break;
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index 0b7a051365..cb02be546e 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -3188,9 +3188,12 @@ ExprResult Sema::MaybeBindToTemporary(Expr *E) {
     }
   }
 
+  CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
+  if (RD->getAttr<ForbidTemporariesAttr>())
+    Diag(E->getExprLoc(), diag::warn_temporaries_forbidden) << E->getType();
+
   // That should be enough to guarantee that this type is complete.
   // If it has a trivial destructor, we can avoid the extra copy.
-  CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
   if (RD->isInvalidDecl() || RD->hasTrivialDestructor())
     return Owned(E);