Paolo Bonzini <[email protected]> writes:
> This allows QObject to be converted to other formats, for example
> JSON via serde_json.
>
> This is not too useful, since QObjects are consumed by
> C code or deserialized into structs, but it can be used for testing
> and it is part of the full implementation of a serde format.
>
> Co-authored-by: Marc-André Lureau <[email protected]>
> Signed-off-by: Marc-André Lureau <[email protected]>
> Signed-off-by: Paolo Bonzini <[email protected]>
> ---
> rust/Cargo.lock | 1 +
> rust/util/Cargo.toml | 1 +
> rust/util/meson.build | 3 +-
> rust/util/src/qobject/mod.rs | 4 +-
> rust/util/src/qobject/serialize.rs | 59 ++++++++++++++++++++++++++++++
> 5 files changed, 65 insertions(+), 3 deletions(-)
> create mode 100644 rust/util/src/qobject/serialize.rs
>
> diff --git a/rust/Cargo.lock b/rust/Cargo.lock
> index 11085133490..7c9f85d5728 100644
> --- a/rust/Cargo.lock
> +++ b/rust/Cargo.lock
> @@ -445,6 +445,7 @@ dependencies = [
> "foreign",
> "glib-sys",
> "libc",
> + "serde",
> ]
>
> [[package]]
> diff --git a/rust/util/Cargo.toml b/rust/util/Cargo.toml
> index 85f91436545..554004816eb 100644
> --- a/rust/util/Cargo.toml
> +++ b/rust/util/Cargo.toml
> @@ -17,6 +17,7 @@ anyhow = { workspace = true }
> foreign = { workspace = true }
> glib-sys = { workspace = true }
> libc = { workspace = true }
> +serde = { workspace = true }
> common = { path = "../common" }
>
> [lints]
> diff --git a/rust/util/meson.build b/rust/util/meson.build
> index ce468ea5227..9fafaf76a37 100644
> --- a/rust/util/meson.build
> +++ b/rust/util/meson.build
> @@ -39,10 +39,11 @@ _util_rs = static_library(
> {'.': _util_bindings_inc_rs,
> 'qobject': [
> 'src/qobject/mod.rs',
> + 'src/qobject/serialize.rs',
> ]}),
> override_options: ['rust_std=2021', 'build.rust_std=2021'],
> rust_abi: 'rust',
> - dependencies: [anyhow_rs, libc_rs, foreign_rs, glib_sys_rs, common_rs,
> qom, qemuutil],
> + dependencies: [anyhow_rs, libc_rs, foreign_rs, glib_sys_rs, common_rs,
> serde_rs, qom, qemuutil],
> )
>
> util_rs = declare_dependency(link_with: [_util_rs])
> diff --git a/rust/util/src/qobject/mod.rs b/rust/util/src/qobject/mod.rs
> index 9c6f168d6e1..0913fabc1ee 100644
> --- a/rust/util/src/qobject/mod.rs
> +++ b/rust/util/src/qobject/mod.rs
> @@ -6,6 +6,8 @@
>
> #![deny(clippy::unwrap_used)]
>
> +mod serialize;
> +
> use std::{
> cell::UnsafeCell,
> ffi::{c_char, CString},
> @@ -230,7 +232,6 @@ fn drop(&mut self) {
> }
> }
>
> -#[allow(unused)]
> macro_rules! match_qobject {
> (@internal ($qobj:expr) =>
> $(() => $unit:expr,)?
> @@ -313,5 +314,4 @@ macro_rules! match_qobject {
> $($type $(($val))? => $code,)+)
> };
> }
> -#[allow(unused_imports)]
> use match_qobject;
> diff --git a/rust/util/src/qobject/serialize.rs
> b/rust/util/src/qobject/serialize.rs
> new file mode 100644
> index 00000000000..34ec3847c1d
> --- /dev/null
> +++ b/rust/util/src/qobject/serialize.rs
> @@ -0,0 +1,59 @@
> +//! `QObject` serialization
> +//!
> +//! This module implements the [`Serialize`] trait for `QObject`,
> +//! allowing it to be converted to other formats, for example
> +//! JSON.
> +
> +use std::{ffi::CStr, mem::ManuallyDrop, ptr::addr_of};
> +
> +use serde::ser::{self, Serialize, SerializeMap, SerializeSeq};
> +
> +use super::{match_qobject, QObject};
> +use crate::bindings;
> +
> +impl Serialize for QObject {
> + #[inline]
> + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
> + where
> + S: ::serde::Serializer,
> + {
> + match_qobject! { (self) =>
> + () => serializer.serialize_unit(),
> + bool(b) => serializer.serialize_bool(b),
> + i64(i) => serializer.serialize_i64(i),
> + u64(u) => serializer.serialize_u64(u),
> + f64(f) => serializer.serialize_f64(f),
> + CStr(cstr) => cstr.to_str().map_or_else(
> + |_| Err(ser::Error::custom("invalid UTF-8 in QString")),
Could this be a programming error? Like flawed input validation?
> + |s| serializer.serialize_str(s),
> + ),
> + QList(l) => {
> + let mut node_ptr = unsafe { l.head.tqh_first };
> + let mut state = serializer.serialize_seq(None)?;
> + while !node_ptr.is_null() {
> + let node = unsafe { &*node_ptr };
> + let elem = unsafe {
> ManuallyDrop::new(QObject::from_raw(addr_of!(*node.value))) };
> + state.serialize_element(&*elem)?;
> + node_ptr = unsafe { node.next.tqe_next };
> + }
> + state.end()
> + },
> + QDict(d) => {
> + let mut state = serializer.serialize_map(Some(d.size))?;
> + let mut e_ptr = unsafe { bindings::qdict_first(d) };
> + while !e_ptr.is_null() {
> + let e = unsafe { &*e_ptr };
> + let key = unsafe { CStr::from_ptr(e.key) };
> + key.to_str().map_or_else(
> + |_| Err(ser::Error::custom("invalid UTF-8 in key")),
> + |k| state.serialize_key(k),
> + )?;
> + let value = unsafe {
> ManuallyDrop::new(QObject::from_raw(addr_of!(*e.value))) };
> + state.serialize_value(&*value)?;
> + e_ptr = unsafe { bindings::qdict_next(d, e) };
> + }
> + state.end()
> + }
> + }
> + }
> +}
