[RFC v3 24/32] qga/rust: generate QGA QAPI types FFI bindings

[marcandre . lureau]

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

Use qapi-gen to generate low-level C FFI bindings for QAPI types,
include them to the build.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 Cargo.lock      |  3 +++
 qga/Cargo.toml  |  3 +++
 qga/lib.rs      |  1 +
 qga/meson.build | 11 +++++++++++
 qga/qapi_ffi.rs |  8 ++++++++
 5 files changed, 26 insertions(+)
 create mode 100644 qga/qapi_ffi.rs

diff --git a/Cargo.lock b/Cargo.lock
index 2f5b202605..ad5bb47762 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -72,3 +72,6 @@ dependencies = [
 [[package]]
 name = "qga"
 version = "0.1.0"
+dependencies = [
+ "common",
+]
diff --git a/qga/Cargo.toml b/qga/Cargo.toml
index a3bffd1fec..807acc947e 100644
--- a/qga/Cargo.toml
+++ b/qga/Cargo.toml
@@ -4,6 +4,9 @@ version = "0.1.0"
 edition = "2018"
 publish = false
 
+[dependencies]
+common = { path = "../rust/common" }
+
 [lib]
 path = "lib.rs"
 crate-type = ["staticlib"]
diff --git a/qga/lib.rs b/qga/lib.rs
index e69de29bb2..17cf43a5e9 100644
--- a/qga/lib.rs
+++ b/qga/lib.rs
@@ -0,0 +1 @@
+mod qapi_ffi;
diff --git a/qga/meson.build b/qga/meson.build
index d272892ced..88d59bef0c 100644
--- a/qga/meson.build
+++ b/qga/meson.build
@@ -56,10 +56,21 @@ qga_ss = qga_ss.apply(config_host, strict: false)
 
 qga_rs = declare_dependency()
 if with_rust
+  qga_qapi_rs_outputs = [
+    'qga-qapi-ffi-types.rs',
+  ]
+
+  qapi_gen_rs_files = custom_target('QGA QAPI Rust bindings',
+                                    output: qga_qapi_rs_outputs,
+                                    input: 'qapi-schema.json',
+                                    command: [ qapi_gen, '-r', '-o', 'qga', 
'-p', 'qga-', '@INPUT0@' ],
+                                    depend_files: qapi_gen_depends)
+
   cargo_qga = custom_target('cargo-qga',
                             build_by_default: true,
                             output: ['libqga.args', 'libqga.a'],
                             build_always_stale: true,
+                            depends: [qapi_gen_rs_files],
                             command: [cargo_wrapper,
                                       meson.current_build_dir(),
                                       meson.current_source_dir(),
diff --git a/qga/qapi_ffi.rs b/qga/qapi_ffi.rs
new file mode 100644
index 0000000000..1f4ade9318
--- /dev/null
+++ b/qga/qapi_ffi.rs
@@ -0,0 +1,8 @@
+#![allow(dead_code)]
+
+use common::libc;
+
+include!(concat!(
+    env!("MESON_BUILD_ROOT"),
+    "/qga/qga-qapi-ffi-types.rs"
+));
-- 
2.33.0.113.g6c40894d24