[libcxx-commits] [PATCH] D119567: [libcxx] String format class marked as packed

[Mark de Wever via Phabricator via libcxx-commits]

Mordante added a comment.

Thanks for fixing these build issues!



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Comment at: libcxx/include/__format/parser_std_format_spec.h:111
   _Type __type{_Type::__default};
-};
+} __attribute__((packed));
 
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hubert.reinterpretcast wrote:
> Use double-underscore form to avoid macro problems.
> 
> Actually, are we assuming GNU attribute support in general "everywhere"?
Is there something like godbolt where I can check the layout on AIX online?
I've been working on some changes regarding this class. In that new version unconditionally pack the struct on all platforms might lead to sub-optimal code. For the current code I don't see an issue with the packing.

> Actually, are we assuming GNU attribute support in general "everywhere"?

I theory yes. The pre-commit CI tests all supported platforms. So when the CI passes it works. (The ASAN errors are unrelated.) But I think it would be cleaner to make the packing conditional.




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  https://reviews.llvm.org/D119567/new/

https://reviews.llvm.org/D119567