Commit graph

13 commits

Author SHA1 Message Date
Paolo Bonzini
e3ff5a17aa rust: macros: check that the first field of a #[derive(Object)] struct is a ParentField
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-01-10 23:34:43 +01:00
Paolo Bonzini
20f0b8e98b rust: macros: check that #[derive(Object)] requires #[repr(C)]
Convert derive_object to the same pattern of first making a
Result<proc_macro2::TokenStream, CompileError>, and then doing
.unwrap_or_else(Into::into) to support checking the validity of
the input.  Add is_c_repr to check that all QOM structs include
a #[repr(C)] attribute.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-01-10 23:34:43 +01:00
Paolo Bonzini
4aed0296b3 rust: rename qemu-api modules to follow C code a bit more
A full match would mean calling them qom::object and hw::core::qdev.  For now,
keep the names shorter but still a bit easier to find.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-12-19 19:36:37 +01:00
Paolo Bonzini
90868c3dce rust: cargo: store desired warning levels in workspace Cargo.toml
An extra benefit of workspaces is that they allow to place lint level
settings in a single Cargo.toml; the settings are then inherited by
packages in the workspace.

Correspondingly, teach rustc_args.py to get the unexpected_cfgs
configuration from the workspace Cargo.toml.

Note that it is still possible to allow or deny warnings per crate or
module, via the #![] attribute syntax.  The rust/qemu-api/src/bindings.rs
file is an example.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-12-10 18:44:06 +01:00
Paolo Bonzini
88dd060db9 rust: qemu-api-macros: always process subprojects before dependencies
Avoid looking for Rust dependencies via cmake.

Reviewed-by: Junjie Mao <junjie.mao@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-11-09 08:34:07 +01:00
Junjie Mao
f351840088 rust: introduce alternative implementation of offset_of!
offset_of! was stabilized in Rust 1.77.0.  Use an alternative implemenation
that was found on the Rust forums, and whose author agreed to license as
MIT for use in QEMU.

The alternative allows only one level of field access, but apart
from this can be used just by replacing core::mem::offset_of! with
qemu_api::offset_of!.

The actual implementation of offset_of! is done in a declarative macro,
but for simplicity and to avoid introducing an extra level of indentation,
the trigger is a procedural macro #[derive(offsets)].

The procedural macro is perhaps a bit overengineered, but it helps
introducing some idioms that will be useful in the future as well.

Signed-off-by: Junjie Mao <junjie.mao@hotmail.com>
Co-developed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-11-05 14:18:16 +01:00
Paolo Bonzini
39c8faefb5 rust: create a cargo workspace
Workspaces allows tracking dependencies for multiple crates at once,
by having a single Cargo.lock file at the top of the rust/ tree.
Because QEMU's Cargo.lock files have to be synchronized with the versions
of crates in subprojects/, using a workspace avoids the need to copy
over the Cargo.lock file when adding a new device (and thus a new crate)
under rust/hw/.

In addition, workspaces let cargo download and build dependencies just
once.  While right now we have one leaf crate (hw/char/pl011), this
will not be the case once more devices are added.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-11-05 14:18:16 +01:00
Paolo Bonzini
907d2bbb80 rust: synchronize dependencies between subprojects and Cargo.lock
The next commit will introduce a new build.rs dependency for rust/qemu-api,
version_check.  Before adding it, ensure that all dependencies are
synchronized between the Meson- and cargo-based build systems.

Note that it's not clear whether in the long term we'll use Cargo for
anything; it seems that the three main uses (clippy, rustfmt, rustdoc)
can all be invoked manually---either via glue code in QEMU, or by
extending Meson to gain the relevant functionality.  However, for
the time being we're stuck with Cargo so it should at least look at
the same code as the rest of the build system.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-11-05 14:18:16 +01:00
Paolo Bonzini
e90d470733 rust: cleanup module_init!, use it from #[derive(Object)]
Remove the duplicate code by using the module_init! macro; at the same time,
simplify how module_init! is used, by taking inspiration from the implementation
of #[derive(Object)].

Reviewed-by: Junjie Mao <junjie.mao@hotmail.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-11-05 14:18:15 +01:00
Paolo Bonzini
4f7521916d rust: modernize link_section usage for ELF platforms
Some newer ABI implementations do not provide .ctors; and while
some linkers rewrite .ctors into .init_array, not all of them do.
Use the newer .init_array ABI, which works more reliably, and
apply it to all non-Apple, non-Windows platforms.

This is similar to how the ctor crate operates; without this change,
"#[derive(Object)]" does not work on Fedora 41.

Reviewed-by: Junjie Mao <junjie.mao@hotmail.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-11-05 14:18:15 +01:00
Paolo Bonzini
be3fc97a09 meson: import rust module into a global variable
Tested-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-11-05 14:18:15 +01:00
Paolo Bonzini
95e82f9b38 meson: check in main meson.build for native Rust compiler
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>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2024-10-14 15:48:05 +01:00
Manos Pitsidianakis
2b74dd9180 rust: add utility procedural macro crate
This commit adds a helper crate library, qemu-api-macros for derive (and
other procedural) macros to be used along qemu-api.

It needs to be a separate library because in Rust, procedural macros, or
macros that can generate arbitrary code, need to be special separate
compilation units.

Only one macro is introduced in this patch, #[derive(Object)]. It
generates a constructor to register a QOM TypeInfo on init and it must
be used on types that implement qemu_api::definitions::ObjectImpl trait.

Reviewed-by: Junjie Mao <junjie.mao@hotmail.com>
Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Link: https://lore.kernel.org/r/dd645642406a6dc2060c6f3f17db2bc77ed67b59.1727961605.git.manos.pitsidianakis@linaro.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-10-11 12:32:17 +02:00