1 files changed, 30 insertions, 1 deletions
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index cab55ea0bf7..d75d705f882 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -328,6 +328,34 @@ static void instantiateOMPDeclareSimdDeclAttr(
       Attr.getRange());
 }
 
+static bool DeclContainsAttr(const Decl *D, const Attr *NewAttr) {
+  if (!D->hasAttrs() || NewAttr->duplicatesAllowed())
+    return false;
+  return llvm::find_if(D->getAttrs(), [NewAttr](const Attr *Attr) {
+           return Attr->getKind() == NewAttr->getKind();
+         }) != D->getAttrs().end();
+}
+
+void Sema::InstantiateAttrsForDecl(
+    const MultiLevelTemplateArgumentList &TemplateArgs, const Decl *Tmpl,
+    Decl *New, LateInstantiatedAttrVec *LateAttrs,
+    LocalInstantiationScope *OuterMostScope) {
+  if (NamedDecl *ND = dyn_cast<NamedDecl>(New)) {
+    for (const auto *TmplAttr : Tmpl->attrs()) {
+      // FIXME: If any of the special case versions from InstantiateAttrs become
+      // applicable to template declaration, we'll need to add them here.
+      CXXThisScopeRAII ThisScope(
+          *this, dyn_cast_or_null<CXXRecordDecl>(ND->getDeclContext()),
+          /*TypeQuals*/ 0, ND->isCXXInstanceMember());
+
+      Attr *NewAttr = sema::instantiateTemplateAttributeForDecl(
+          TmplAttr, Context, *this, TemplateArgs);
+      if (NewAttr && !DeclContainsAttr(New, NewAttr))
+        New->addAttr(NewAttr);
+    }
+  }
+}
+
 void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
                             const Decl *Tmpl, Decl *New,
                             LateInstantiatedAttrVec *LateAttrs,
@@ -421,7 +449,8 @@ void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
 
       Attr *NewAttr = sema::instantiateTemplateAttribute(TmplAttr, Context,
                                                          *this, TemplateArgs);
-      if (NewAttr)
+
+      if (NewAttr && !DeclContainsAttr(New, NewAttr))
         New->addAttr(NewAttr);
     }
   }