================
@@ -132,9 +132,20 @@ bool Sema::CheckCountedByAttrOnField(FieldDecl *FD, Expr 
*E, bool CountInBytes,
     // `BoundsSafetyCheckUseOfCountAttrPtr`
     //
     // * When the pointee type is always an incomplete type (e.g.
-    // `void`) the attribute is disallowed by this method because we know the
-    // type can never be completed so there's no reason to allow it.
-    InvalidTypeKind = CountedByInvalidPointeeTypeKind::INCOMPLETE;
+    // `void` in strict C mode) the attribute is disallowed by this method
+    // because we know the type can never be completed so there's no reason
+    // to allow it.
+    //
+    // Exception: In GNU mode, void has an implicit size of 1 byte for pointer
+    // arithmetic. Therefore, counted_by on void* is allowed as a GNU extension
+    // and behaves equivalently to sized_by (treating the count as bytes).
+    bool IsVoidPtrInGNUMode = PointeeTy->isVoidType() && getLangOpts().GNUMode;
----------------
delcypher wrote:

@rapidsna What do you think about changing this to

```
 bool IsVoidPtrInGNUMode = PointeeTy->isVoidType() && getLangOpts().GNUMode && 
!getLangOpts().BoundsSafety;
```

?

This would mean in the `-fbounds-safety` language model we would still disallow 
this. Or for consistency with `-fno-bounds-safety` do you think we should allow 
this language extension.

https://github.com/llvm/llvm-project/pull/164737
_______________________________________________
cfe-commits mailing list
[email protected]
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

Reply via email to