Generalise support for non-inheritable attributes

Inheritable attributes on declarations may be inherited by any later
redeclaration at merge time.  By contrast, a non-inheritable attribute
will not be inherited by later redeclarations.  Non-inheritable
attributes may be semantically analysed early, allowing them to
influence the redeclaration/overloading process.

Before this change, the "overloadable" attribute received special
handling to be treated as non-inheritable, while all other attributes
were treated as inheritable.  This patch generalises the concept,
while removing a FIXME.  Some CUDA location attributes are also marked
as non-inheritable in order to support special overloading semantics
(to be introduced in a later patch).

The patch introduces a new Attr subclass, InheritableAttr, from
which all inheritable attributes derive.  Non-inheritable attributes
simply derive from Attr.

N.B. I did not review every attribute to determine whether it should
be marked non-inheritable.  This can be done later on an incremental
basis, as this change does not affect default functionality.

llvm-svn: 123959

1 files changed, 5 insertions, 5 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index a3c3242a4e4..8c78c0dd764 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -1019,11 +1019,11 @@ static void MergeDeclAttributes(Decl *New, Decl *Old, ASTContext &C) {
   // we process them.
   if (!New->hasAttrs())
     New->setAttrs(AttrVec());
-  for (Decl::attr_iterator i = Old->attr_begin(), e = Old->attr_end(); i != e;
-       ++i) {
-    // FIXME: Make this more general than just checking for Overloadable.
-    if (!DeclHasAttr(New, *i) && (*i)->getKind() != attr::Overloadable) {
-      Attr *NewAttr = (*i)->clone(C);
+  for (specific_attr_iterator<InheritableAttr>
+       i = Old->specific_attr_begin<InheritableAttr>(),
+       e = Old->specific_attr_end<InheritableAttr>(); i != e; ++i) {
+    if (!DeclHasAttr(New, *i)) {
+      InheritableAttr *NewAttr = cast<InheritableAttr>((*i)->clone(C));
       NewAttr->setInherited(true);
       New->addAttr(NewAttr);
     }