<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>davidbalbert</author><text>The article references a few compiler extensions: __builtin_xnu_type_signature, __builtin_xnu_type_summary, and the xnu_usage_semantics attribute.&lt;p&gt;I can see references to these builtins in the latest xnu source[1], but not in upstream llvm[2], or Apple&amp;#x27;s forks of llvm[3] and clang[4].&lt;p&gt;It&amp;#x27;s been possible to build your own XNU[5] for a long time. Is that still possible now?&lt;p&gt;&lt;pre&gt;&lt;code&gt;  [1]: https:&amp;#x2F;&amp;#x2F;github.com&amp;#x2F;apple-oss-distributions&amp;#x2F;xnu
  [2]: https:&amp;#x2F;&amp;#x2F;github.com&amp;#x2F;llvm&amp;#x2F;llvm-project
  [3]: https:&amp;#x2F;&amp;#x2F;github.com&amp;#x2F;apple-oss-distributions&amp;#x2F;llvmCore
  [4]: https:&amp;#x2F;&amp;#x2F;github.com&amp;#x2F;apple-oss-distributions&amp;#x2F;clang
  [5]: https:&amp;#x2F;&amp;#x2F;kernelshaman.blogspot.com&amp;#x2F;2021&amp;#x2F;02&amp;#x2F;building-xnu-for-macos-112-intel-apple.html&lt;/code&gt;&lt;/pre&gt;</text><parent_chain></parent_chain></comment><story><title>Towards the next generation of XNU memory safety: kalloc_type</title><url>https://security.apple.com/blog/towards-the-next-generation-of-xnu-memory-safety/</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>MBCook</author><text>Very interesting. Unfortunately I don’t see a way to follow new entries. There’s no RSS feed.</text><parent_chain></parent_chain></comment><story><title>Towards the next generation of XNU memory safety: kalloc_type</title><url>https://security.apple.com/blog/towards-the-next-generation-of-xnu-memory-safety/</url></story>