[Bounds-Safety] Add sized_by, counted_by_or_null & sized_by_or_null (#93231)

The attributes `sized_by`, `counted_by_or_null` and `sized_by_or_null`
have been added as variants on `counted_by`, each with slightly
different semantics. `sized_by` takes a byte size parameter instead of
an element count, allowing pointees with unknown size. The
`counted_by_or_null` and `sized_by_or_null` variants are equivalent to
their base variants, except the pointer can be null regardless of
count/size value. If the pointer is null the size is effectively 0.

rdar://125400354

1 files changed, 6 insertions, 4 deletions

diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index 0aae5f3..7ce9a9c 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -700,7 +700,10 @@ void Parser::ParseGNUAttributeArgs(
     ParseAttributeWithTypeArg(*AttrName, AttrNameLoc, Attrs, ScopeName,
                               ScopeLoc, Form);
     return;
-  } else if (AttrKind == ParsedAttr::AT_CountedBy) {
+  } else if (AttrKind == ParsedAttr::AT_CountedBy ||
+             AttrKind == ParsedAttr::AT_CountedByOrNull ||
+             AttrKind == ParsedAttr::AT_SizedBy ||
+             AttrKind == ParsedAttr::AT_SizedByOrNull) {
     ParseBoundsAttribute(*AttrName, AttrNameLoc, Attrs, ScopeName, ScopeLoc,
                          Form);
     return;
@@ -4866,9 +4869,8 @@ static void DiagnoseCountAttributedTypeInUnnamedAnon(ParsingDeclSpec &DS,
 
     for (const auto &DD : CAT->dependent_decls()) {
       if (!RD->containsDecl(DD.getDecl())) {
-        P.Diag(VD->getBeginLoc(),
-               diag::err_flexible_array_count_not_in_same_struct)
-            << DD.getDecl();
+        P.Diag(VD->getBeginLoc(), diag::err_count_attr_param_not_in_same_struct)
+            << DD.getDecl() << CAT->getKind() << CAT->isArrayType();
         P.Diag(DD.getDecl()->getBeginLoc(),
                diag::note_flexible_array_counted_by_attr_field)
             << DD.getDecl();