Re: [PATCH 1/2] rust: kasan: do not pass -Zsanitizer-recover

[Gary Guo]

On Wed Mar 25, 2026 at 2:04 PM GMT, Danilo Krummrich wrote:
> On Wed Mar 25, 2026 at 12:47 PM CET, Alice Ryhl wrote:
>> On Wed, Mar 25, 2026 at 12:06:50PM +0100, Danilo Krummrich wrote:
>>> On Wed Mar 25, 2026 at 10:26 AM CET, Alice Ryhl wrote:
>>> > We do not pass -fsanitize-recover to clang, so for consistency we should
>>> > not pass -Zsanitizer-recover to rustc. Thus, remove these flags.
>>> 
>>> Isn't this because clang forces it regardless? Is this true for rustc as well?
>>
>> I forgot to mention this in commit, but I'm actually a bit confused
>> about the situation here. If clang forces it somehow, how?
>
> I previously had a very brief look at the source code and came across this [1],
> where
>
> 	static const SanitizerMask AlwaysRecoverable = SanitizerKind::KernelAddress |
> 	                                               SanitizerKind::KernelHWAddress |
> 	                                               SanitizerKind::KCFI;
>
> But again, I only had a very brief look and it might well be that I got this
> wrong.
>
> [1] https://github.com/llvm/llvm-project/blob/main/clang/lib/Driver/SanitizerArgs.cpp#L750
>
>> I don't think rustc does anything like that, but not sure. If it doesn't, but
>> clang does, then maybe rustc should too? Depends on how that happens.

It looks like there's no similar logic, and Rustc is passing recoverable
settings based on the command line options:

https://github.com/rust-lang/rust/blob/8a703520e80d87d4423c01f9d4fbc9e5f6533a02/compiler/rustc_codegen_llvm/src/back/write.rs#L644

Best,
Gary