[clang] [clang] Avoid invalid recovery cast for non-pointer Class redefinitions (PR #213590)

[Gauarv Chaudhary via cfe-commits]

https://github.com/ANAMASGARD updated https://github.com/llvm/llvm-project/pull/213590

>From 0237bc2c44324d3ae4f02e8c8992b96c6d1e2bbd Mon Sep 17 00:00:00 2001
From: Gaurav Chaudhary <chaudharygaurav2004 at gmail.com>
Date: Mon, 3 Aug 2026 10:17:56 +0530
Subject: [PATCH] [clang] Avoid invalid recovery cast for non-pointer Class
 redefinitions

ShouldTryAgainWithRedefinitionType() can attempt to recover builtin Objective-C id/
    Class member access using a user-written non-pointer redefinition. This constructs a
    CK_BitCast between incompatible type categories and violates CastExpr's AST invariants.

  Reject non-pointer redefinition types before attempting the recovery cast, while preserving
  recovery for C and Objective-C object pointers.

  Fixes #213066

Signed-off-by: Gaurav Chaudhary <chaudharygaurav2004 at gmail.com>
---
 clang/lib/Sema/SemaExprMember.cpp | 5 +++++
 clang/test/SemaObjCXX/gh213066.mm | 9 +++++++++
 2 files changed, 14 insertions(+)
 create mode 100644 clang/test/SemaObjCXX/gh213066.mm

diff --git a/clang/lib/Sema/SemaExprMember.cpp b/clang/lib/Sema/SemaExprMember.cpp
index 62ecc52c0374b..f42b94c216660 100644
--- a/clang/lib/Sema/SemaExprMember.cpp
+++ b/clang/lib/Sema/SemaExprMember.cpp
@@ -1188,6 +1188,11 @@ static bool ShouldTryAgainWithRedefinitionType(Sema &S, ExprResult &base) {
     return false;
   }
 
+  // Only retry with pointer redefinition types, since a non-pointer
+  // destination would produce an invalid CK_BitCast.
+  if (!redef->isAnyPointerType())
+    return false;
+
   // Do the substitution as long as the redefinition type isn't just a
   // possibly-qualified pointer to builtin-id or builtin-Class again.
   opty = redef->getAs<ObjCObjectPointerType>();
diff --git a/clang/test/SemaObjCXX/gh213066.mm b/clang/test/SemaObjCXX/gh213066.mm
new file mode 100644
index 0000000000000..58123a3640a4a
--- /dev/null
+++ b/clang/test/SemaObjCXX/gh213066.mm
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 -triple x86_64-apple-macosx -fsyntax-only -verify -x objective-c++ %s
+// REQUIRES: asserts
+
+typedef struct {} Class;
+
+void test() {
+  Class c;
+  c.className; // expected-error {{member reference base type 'Class' is not a structure or union}}
+}