Re: [PATCH] meson: check in main meson.build for native Rust compiler

[Peter Maydell <peter.maydell@linaro.org>]

On Mon, 14 Oct 2024 at 15:36, Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> A working native Rust compiler is always needed in order to compile Rust
> code, even when cross compiling, in order to build the procedural macros
> that QEMU uses.
>
> Right now, the check is done in rust/qemu-api-macros/meson.build, but this
> has two disadvantages.  First, it makes the build fail when the Meson "rust"
> option is set to "auto" (instead, Rust support should be disabled).  Second,
> add_languages() is one of the few functions that are executed even by
> "meson introspect", except that "meson introspect" executes both branches
> of "if" statements!  Therefore, "meson introspect" tries to look for a
> Rust compiler even if the option is disabled---and then fails because
> the compiler is required by rust/qemu-api-macros/meson.build.  This is
> visible for example if the compilation host has a stale
> scripts/meson-buildoptions.sh and no rustc installed.
>
> Both issues can be fixed by moving the check to the main meson.build,
> together with the check for the cross compiler.
>
> Reported-by: Peter Maydell <peter.maydell@linaro.org>
> ---


Applied directly to git, thanks.

-- PMM