subprojects: add the foreign crate

This is a cleaned up and separated version of the patches at
https://lore.kernel.org/all/20240701145853.1394967-4-pbonzini@redhat.com/
https://lore.kernel.org/all/20240701145853.1394967-5-pbonzini@redhat.com/

Its first user will be the Error bindings; for example a QEMU Error ** can be
converted to a Rust Option using

     unsafe { Option::<Error>::from_foreign(c_error) }

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

rust/meson.build

@@ -1,11 +1,13 @@
 subproject('anyhow-1-rs', required: true)
 subproject('bilge-0.2-rs', required: true)
 subproject('bilge-impl-0.2-rs', required: true)
+subproject('foreign-0.3-rs', required: true)
 subproject('libc-0.2-rs', required: true)
 
 anyhow_rs = dependency('anyhow-1-rs')
 bilge_rs = dependency('bilge-0.2-rs')
 bilge_impl_rs = dependency('bilge-impl-0.2-rs')
+foreign_rs = dependency('foreign-0.3-rs')
 libc_rs = dependency('libc-0.2-rs')
 
 subproject('proc-macro2-1-rs', required: true)

rust/qemu-api/meson.build

@@ -35,7 +35,7 @@ _qemu_api_rs = static_library(
   override_options: ['rust_std=2021', 'build.rust_std=2021'],
   rust_abi: 'rust',
   rust_args: _qemu_api_cfg,
-  dependencies: [anyhow_rs, libc_rs, qemu_api_macros, qemuutil_rs,
+  dependencies: [anyhow_rs, foreign_rs, libc_rs, qemu_api_macros, qemuutil_rs,
                  qom, hwcore, chardev, migration],
 )
 

scripts/archive-source.sh

@@ -28,7 +28,8 @@ sub_file="${sub_tdir}/submodule.tar"
 # different to the host OS.
 subprojects="keycodemapdb libvfio-user berkeley-softfloat-3
   berkeley-testfloat-3 anyhow-1-rs arbitrary-int-1-rs bilge-0.2-rs
-  bilge-impl-0.2-rs either-1-rs itertools-0.11-rs libc-0.2-rs proc-macro2-1-rs
+  bilge-impl-0.2-rs either-1-rs foreign-0.3-rs itertools-0.11-rs
+  libc-0.2-rs proc-macro2-1-rs
   proc-macro-error-1-rs proc-macro-error-attr-1-rs quote-1-rs
   syn-2-rs unicode-ident-1-rs"
 sub_deinit=""

scripts/make-release

@@ -41,7 +41,8 @@ fi
 # Only include wraps that are invoked with subproject()
 SUBPROJECTS="libvfio-user keycodemapdb berkeley-softfloat-3
   berkeley-testfloat-3 anyhow-1-rs arbitrary-int-1-rs bilge-0.2-rs
-  bilge-impl-0.2-rs either-1-rs itertools-0.11-rs libc-0.2-rs proc-macro2-1-rs
+  bilge-impl-0.2-rs either-1-rs foreign-0.3-rs itertools-0.11-rs
+  libc-0.2-rs proc-macro2-1-rs
   proc-macro-error-1-rs proc-macro-error-attr-1-rs quote-1-rs
   syn-2-rs unicode-ident-1-rs"
 

subprojects/.gitignore

@@ -11,6 +11,7 @@
 /bilge-0.2.0
 /bilge-impl-0.2.0
 /either-1.12.0
+/foreign-0.3.1
 /itertools-0.11.0
 /libc-0.2.162
 /proc-macro-error-1.0.4

subprojects/foreign-0.3-rs.wrap

@@ -0,0 +1,7 @@
+[wrap-file]
+directory = foreign-0.3.1
+source_url = https://crates.io/api/v1/crates/foreign/0.3.1/download
+source_filename = foreign-0.3.1.tar.gz
+source_hash = 17ca1b5be8c9d320daf386f1809c7acc0cb09accbae795c2001953fa50585846
+#method = cargo
+patch_directory = foreign-0.3-rs

subprojects/packagefiles/foreign-0.3-rs/meson.build

@@ -0,0 +1,26 @@
+project('foreign-0.3-rs', 'rust',
+  meson_version: '>=1.5.0',
+  version: '0.2.0',
+  license: 'MIT OR Apache-2.0',
+  default_options: [])
+
+subproject('libc-0.2-rs', required: true)
+libc_rs = dependency('libc-0.2-rs')
+
+_foreign_rs = static_library(
+  'foreign',
+  files('src/lib.rs'),
+  gnu_symbol_visibility: 'hidden',
+  override_options: ['rust_std=2021', 'build.rust_std=2021'],
+  rust_abi: 'rust',
+  rust_args: [
+    '--cap-lints', 'allow',
+  ],
+  dependencies: [libc_rs],
+)
+
+foreign_dep = declare_dependency(
+  link_with: _foreign_rs,
+)
+
+meson.override_dependency('foreign-0.3-rs', foreign_dep)