[PATCH 13/14] rust/util: build QAPI types

[Paolo Bonzini <pbonzini@redhat.com>]

From: Marc-André Lureau <marcandre.lureau@redhat.com>

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 rust/util/wrapper.h          |  1 +
 qapi/meson.build             |  6 ++++++
 rust/Cargo.lock              |  1 +
 rust/util/Cargo.toml         |  1 +
 rust/util/meson.build        | 18 +++++++++++++++++-
 rust/util/src/qobject/mod.rs |  9 +++++++++
 6 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/rust/util/wrapper.h b/rust/util/wrapper.h
index 0907dd59142..c88820a5e5b 100644
--- a/rust/util/wrapper.h
+++ b/rust/util/wrapper.h
@@ -37,3 +37,4 @@ typedef enum memory_order {
 #include "qobject/qobject.h"
 #include "qobject/qlist.h"
 #include "qobject/qdict.h"
+#include "qobject/qjson.h"
diff --git a/qapi/meson.build b/qapi/meson.build
index ca6b61a608d..5d4b55b47f8 100644
--- a/qapi/meson.build
+++ b/qapi/meson.build
@@ -129,3 +129,9 @@ foreach output : qapi_outputs
   util_ss.add(qapi_files[i])
   i = i + 1
 endforeach
+
+qapi_rs_files = custom_target('QAPI Rust',
+  output: 'qapi-types.rs',
+  input: [ files('qapi-schema.json') ],
+  command: [ qapi_gen, '-o', 'qapi', '-b', '@INPUT0@', '-B', 'qapi.backend.QAPIRsBackend' ],
+  depend_files: [ qapi_inputs, qapi_gen_depends ])
diff --git a/rust/Cargo.lock b/rust/Cargo.lock
index c1075e11d6c..991533d92c1 100644
--- a/rust/Cargo.lock
+++ b/rust/Cargo.lock
@@ -447,6 +447,7 @@ dependencies = [
  "glib-sys",
  "libc",
  "serde",
+ "serde_derive",
 ]
 
 [[package]]
diff --git a/rust/util/Cargo.toml b/rust/util/Cargo.toml
index 554004816eb..9f6c52c5acd 100644
--- a/rust/util/Cargo.toml
+++ b/rust/util/Cargo.toml
@@ -18,6 +18,7 @@ foreign = { workspace = true }
 glib-sys = { workspace = true }
 libc = { workspace = true }
 serde = { workspace = true }
+serde_derive = { workspace = true }
 common = { path = "../common" }
 
 [lints]
diff --git a/rust/util/meson.build b/rust/util/meson.build
index 45366d03786..a2d0e6ded0d 100644
--- a/rust/util/meson.build
+++ b/rust/util/meson.build
@@ -50,7 +50,7 @@ _util_rs = static_library(
   dependencies: [anyhow_rs, libc_rs, foreign_rs, glib_sys_rs, common_rs, serde_rs, qom, qemuutil],
 )
 
-util_rs = declare_dependency(link_with: [_util_rs], dependencies: [qemuutil, qom])
+util_rs = declare_dependency(link_with: [_util_rs], dependencies: [])
 
 rust.test('rust-util-tests', _util_rs,
           dependencies: [qemuutil, qom],
@@ -64,3 +64,19 @@ rust.doctest('rust-util-rs-doctests',
      dependencies: util_rs,
      suite: ['doc', 'rust']
 )
+
+_qapi_cfg = run_command(rustc_args,
+  '--no-strict-cfg',
+  '--config-headers', config_host_h,
+  capture: true, check: true).stdout().strip().splitlines()
+
+_qapi_rs = static_library(
+  'qapi',
+  qapi_rs_files,
+  rust_args: _qapi_cfg,
+  override_options: ['rust_std=2021', 'build.rust_std=2021'],
+  rust_abi: 'rust',
+  dependencies: [common_rs, util_rs, serde_rs],
+)
+
+qapi_rs = declare_dependency(link_with: [_qapi_rs])
diff --git a/rust/util/src/qobject/mod.rs b/rust/util/src/qobject/mod.rs
index b6e86f11a64..f2618c86473 100644
--- a/rust/util/src/qobject/mod.rs
+++ b/rust/util/src/qobject/mod.rs
@@ -13,6 +13,7 @@
 mod serializer;
 
 use core::fmt::{self, Debug, Display};
+use foreign::prelude::*;
 use std::{
     cell::UnsafeCell,
     ffi::{c_char, CString},
@@ -104,6 +105,14 @@ fn refcnt(&self) -> &AtomicUsize {
         let qobj = self.0.get();
         unsafe { AtomicUsize::from_ptr(addr_of_mut!((*qobj).base.refcnt)) }
     }
+
+    pub fn to_json(&self) -> String {
+        let qobj = self.0.get();
+        unsafe {
+            let json = bindings::qobject_to_json(qobj);
+            glib_sys::g_string_free(json, glib_sys::GFALSE).into_native()
+        }
+    }
 }
 
 impl From<()> for QObject {
-- 
2.51.0