Re: [PATCH] rust: Prefer link_with over link_whole

[Paolo Bonzini <pbonzini@redhat.com>]

On 2/18/25 09:37, Zhao Liu wrote:
> The commit fccb744f41c6 ("gdbstub: Try unlinking the unix socket before
> binding") causes the compilation of rust-qemu-api-integration to fail,
> because rust-qemu-api-integration uses link_whole which meets the
> duplicate symbol linker error.
> 
> Though it's not the issue of link_whole used by Rust side, there's no
> need to use link_whole.
> 
> Use link_with, which may also bring some benefits, such as faster
> linking or smaller output files.

link_with, if I remember correctly, drops the constructors.  Using it in 
rust_devices_ss therefore prevents the devices from being registered 
with QOM.

The real issue is lack of support for "objects" in Meson for Rust 
executables.  A patch to fix that is under review, after which it will 
be possible to build Rust executables using the same "dependency" 
objects as C code.

Paolo

>   rust_devices_ss.add(when: 'CONFIG_X_PL011_RUST', if_true: [declare_dependency(
> -  link_whole: [_libpl011_rs],
> +  link_with: [_libpl011_rs],
>     # Putting proc macro crates in `dependencies` is necessary for Meson to find
>     # them when compiling the root per-target static rust lib.
>     dependencies: [bilge_impl_dep, qemu_api_macros],
> diff --git a/rust/hw/timer/hpet/meson.build b/rust/hw/timer/hpet/meson.build
> index c2d7c0532ca4..ce90cc4f021a 100644
> --- a/rust/hw/timer/hpet/meson.build
> +++ b/rust/hw/timer/hpet/meson.build
> @@ -10,7 +10,7 @@ _libhpet_rs = static_library(
>   )
>   
>   rust_devices_ss.add(when: 'CONFIG_X_HPET_RUST', if_true: [declare_dependency(
> -  link_whole: [_libhpet_rs],
> +  link_with: [_libhpet_rs],
>     # Putting proc macro crates in `dependencies` is necessary for Meson to find
>     # them when compiling the root per-target static rust lib.
>     dependencies: [qemu_api_macros],
> diff --git a/rust/qemu-api/meson.build b/rust/qemu-api/meson.build
> index 2e9c1078b9b2..e825671b694b 100644
> --- a/rust/qemu-api/meson.build
> +++ b/rust/qemu-api/meson.build
> @@ -63,7 +63,7 @@ test('rust-qemu-api-integration',
>           rust_args: ['--test'],
>           install: false,
>           dependencies: [qemu_api, qemu_api_macros],
> -        link_whole: [rust_qemu_api_objs, libqemuutil]),
> +        link_with: [rust_qemu_api_objs, libqemuutil]),
>       args: [
>           '--test', '--test-threads', '1',
>           '--format', 'pretty',