clang/AST/Type: fix sizeof static assertion on Windows.

Co-Authored-By: Codex CLI <codex@openai.com>

Author: adriweb

clang/include/clang/AST/Type.h

@@ -2226,21 +2226,6 @@ class alignas(TypeAlignment) Type : public ExtQualsTypeCommonBase {
     unsigned NumExpansions;
   };
 
-  class CountAttributedTypeBitfields {
-    friend class CountAttributedType;
-
-    LLVM_PREFERRED_TYPE(TypeBitfields)
-    unsigned : NumTypeBits;
-
-    static constexpr unsigned NumCoupledDeclsBits = 4;
-    unsigned NumCoupledDecls : NumCoupledDeclsBits;
-    LLVM_PREFERRED_TYPE(bool)
-    unsigned CountInBytes : 1;
-    LLVM_PREFERRED_TYPE(bool)
-    unsigned OrNull : 1;
-  };
-  static_assert(sizeof(CountAttributedTypeBitfields) <= sizeof(unsigned));
-
   union {
     TypeBitfields TypeBits;
     ArrayTypeBitfields ArrayTypeBits;
@@ -2263,7 +2248,6 @@ class alignas(TypeAlignment) Type : public ExtQualsTypeCommonBase {
     DependentTemplateSpecializationTypeBitfields
       DependentTemplateSpecializationTypeBits;
     PackExpansionTypeBitfields PackExpansionTypeBits;
-    CountAttributedTypeBitfields CountAttributedTypeBits;
   };
 
 private:
@@ -3269,7 +3253,19 @@ class CountAttributedType final
                                    TypeCoupledDeclRefInfo> {
   friend class ASTContext;
 
+public:
+  enum DynamicCountPointerKind {
+    CountedBy = 0,
+    SizedBy,
+    CountedByOrNull,
+    SizedByOrNull,
+  };
+
+private:
   Expr *CountExpr;
+  LLVM_PREFERRED_TYPE(DynamicCountPointerKind)
+  unsigned Kind : 2;
+
   /// \p CountExpr represents the argument of __counted_by or the likes. \p
   /// CountInBytes indicates that \p CountExpr is a byte count (i.e.,
   /// __sized_by(_or_null)) \p OrNull means it's an or_null variant (i.e.,
@@ -3281,29 +3277,20 @@ class CountAttributedType final
                       ArrayRef<TypeCoupledDeclRefInfo> CoupledDecls);
 
   unsigned numTrailingObjects(OverloadToken<TypeCoupledDeclRefInfo>) const {
-    return CountAttributedTypeBits.NumCoupledDecls;
+    return Decls.size();
   }
 
 public:
-  enum DynamicCountPointerKind {
-    CountedBy = 0,
-    SizedBy,
-    CountedByOrNull,
-    SizedByOrNull,
-  };
-
   Expr *getCountExpr() const { return CountExpr; }
-  bool isCountInBytes() const { return CountAttributedTypeBits.CountInBytes; }
-  bool isOrNull() const { return CountAttributedTypeBits.OrNull; }
+  bool isCountInBytes() const { return static_cast<unsigned>(getKind()) & 1; }
+  bool isOrNull() const { return static_cast<unsigned>(getKind()) & 2; }
 
   DynamicCountPointerKind getKind() const {
-    if (isOrNull())
-      return isCountInBytes() ? SizedByOrNull : CountedByOrNull;
-    return isCountInBytes() ? SizedBy : CountedBy;
+    return static_cast<DynamicCountPointerKind>(Kind);
   }
 
   void Profile(llvm::FoldingSetNodeID &ID) {
-    Profile(ID, desugar(), CountExpr, isCountInBytes(), isOrNull());
+    Profile(ID, desugar(), getCountExpr(), isCountInBytes(), isOrNull());
   }
 
   static void Profile(llvm::FoldingSetNodeID &ID, QualType WrappedTy,

clang/lib/AST/Type.cpp

@@ -3849,10 +3849,9 @@ CountAttributedType::CountAttributedType(
     QualType Wrapped, QualType Canon, Expr *CountExpr, bool CountInBytes,
     bool OrNull, ArrayRef<TypeCoupledDeclRefInfo> CoupledDecls)
     : BoundsAttributedType(CountAttributed, Wrapped, Canon),
-      CountExpr(CountExpr) {
-  CountAttributedTypeBits.NumCoupledDecls = CoupledDecls.size();
-  CountAttributedTypeBits.CountInBytes = CountInBytes;
-  CountAttributedTypeBits.OrNull = OrNull;
+      CountExpr(CountExpr),
+      Kind(OrNull ? (CountInBytes ? SizedByOrNull : CountedByOrNull)
+                  : (CountInBytes ? SizedBy : CountedBy)) {
   auto *DeclSlot = getTrailingObjects<TypeCoupledDeclRefInfo>();
   Decls = llvm::ArrayRef(DeclSlot, CoupledDecls.size());
   for (unsigned i = 0; i != CoupledDecls.size(); ++i)