On Thu, 08 Aug 2024 09:10, Paolo Bonzini <pbonzini@redhat.com> wrote:
>On 8/4/24 23:04, Manos Pitsidianakis wrote:
>> Changes
>> =======
>>
>> - Setting MSRV to 1.77.0:
>> * cstr crate MSRV is 1.64, which is more recent than Debian bookworm
>> (1.63.0) <https://github.com/upsuper/cstr/blob/master/Cargo.toml>
>>
>> * pl011's dependencies (mostly proc-macro2) don't support 1.63.0
>
>proc-macro2 is listed as supporting 1.56.0, and in general I don't see
>particularly high MSRVs for any of your dependencies.
The issue was with transitive deps, proc-macro-error crates etc stopped
compiling when lowering the version, which means we'd have to patch the
dependency's dependency to see if that'd work; otherwise, yes!
>
>cstr needs to use version 0.2.10 in order to work with Rust 1.63.0.
>
>As discussed on IRC, there are obvious advantages and disadvantages to
>using meson. The main disadvantage is the extra work when bumping the
>version of the dependencies or when adding a new one. The advantage is
>more uniformity and less moving parts. Overall, I think it's doable to
>use it. Dependencies will mostly be added in the early days of QEMU,
>and won't be updated too often due to our MSRV constraints.
>
>The automatic Cargo.toml support in Meson is promising, but it doesn't
>work right now when cross compiling build-time dependencies (which have
>to use "native: true" or Meson rightly warns about mixing build-machine
>and host-machine binaries). So right now we'd have to write meson.build
>by hand for those.
>
>My suggestion is however to name our manually-managed subprojects with
>the same convention that is used by "method = cargo" in Meson 1.5.0+,
>i.e. name-APIVER-rs:
>
> arbitrary-int-1-rs.wrap
> bilge-0.2-rs.wrap
> bilge-impl-0.2-rs.wrap
> either-1-rs.wrap
> itertools-0.11-rs.wrap
> proc-macro2-1-rs.wrap
> proc-macro-error-1-rs.wrap
> proc-macro-error-attr-1-rs.wrap
> quote-1-rs.wrap
> syn-2-rs.wrap
> unicode-ident-1-rs.wrap
>
>and to access dependencies using meson.override_dependency() and
>dependency(), instead of get_variable(). This at least reduces future
>churn.
Yes that makes sense!
>
>As to the individual patches:
>
>- for patch 1, roughly the same changes I had made for cargo can be done
>for rustc, so that the cross file contains the right --target option.
>I'll reply to the individual patch.
That'd be great since I'm not familiar with how the cross file works.
>
>- for patch 2, the only issue is that you are specifying
>--no-include-path-detection and that breaks for me on Fedora. I have
>not finished testing but it seems that it's enough to remove that line.
I had added that when trying to debug bindgen failing to find headers
when dependencies were added (e.g. linux io_uring) or when compiling on
macos, let's test again to see if it's indeed unnecessary!
>
>- for patches 4 and 5, I have minimal comments on the meson.build. For
>patch 5, however, I have already done the above renaming as part of
>getting cross compilation to work. We can synchronize on IRC on the
>best way of getting the changes to you.
>
Sounds good to me.
Thanks,
Manos