Re: Rust kernel policy

Alexey Dobriyan
2025-02-20T06:32:19Z

On Wed, Feb 19, 2025 at 11:33:56AM -0800, H. Peter Anvin wrote:
> b. Can we use existing mature tools, such as C++, to *immediately* improve the quality (not just memory safety!) of our 37-year-old, 35-million line code base and allow for further centralized improvements without the major lag required for compiler extensions to be requested and implemented in gcc (and clang) *and* dealing with the maturity issue?

We can't and for technical reasons:

* g++ requires C99 initializers to be in declaration order,
even in cases where there is no reason to do so.

* g++ doesn't support __seg_gs at all:

$ echo -n -e 'int __seg_gs gs;' | g++ -xc++ - -S -o /dev/null
<stdin>:1:14: error: expected initializer before ‘gs’

x86 added this to improve codegen quality so this would be step backwards.