[clang] [BoundsSafety][NFC] Add counted_by type-shape validation helper (PR #227774)

[Yeoul Na via cfe-commits]

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@@ -49,6 +77,123 @@ enum class CountedByInvalidPointeeTypeKind {
   VALID,
 };
 
+/// Check type conflicts under the -fbounds-safety attribute model.
+/// Return std::nullopt if validation should continue with the shared checks.
+static std::optional<bool> checkBoundsAttrTypeConflictsAndMisc(
+    Sema &S, QualType Ty, SourceLocation AttrLoc,
+    const Sema::BoundsAttrFlags &Flags, StringRef AttrSpelling,
+    bool AllowRedecl, Expr *AttrArg) {
+  // The -fbounds-safety model's checks for conflicting attributes, atomic
+  // pointers and array shapes are not upstream yet.
+  return std::nullopt;
+}
+
+bool Sema::ValidateBoundsAttrTypeShape(QualType Ty, SourceLocation AttrLoc,
+                                       SourceRange AttrRange,
+                                       BoundsAttrFlags &Flags,
+                                       StringRef AttrSpelling, bool AllowRedecl,
+                                       Expr *AttrArg, bool UpdateFlags) {
+  if (getLangOpts().hasBoundsSafetyAttributes())
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rapidsna wrote:

Okay. Let's try to keep then.

https://github.com/llvm/llvm-project/pull/227774