cargo: Add support for system-deps dependencies

mesonbuild/cargo/interpreter.py

@@ -155,6 +155,39 @@ class Package:
     def __post_init__(self) -> None:
         self.api = _version_to_api(self.version)
 
+@dataclasses.dataclass
+class SystemDependency:
+
+    """ Representation of a Cargo system-deps entry
+        https://docs.rs/system-deps/latest/system_deps
+    """
+
+    name: str
+    version: T.List[str]
+    optional: bool
+    feature: T.Optional[str]
+    feature_overrides: T.Dict[str, T.Dict[str, str]]
+
+    @classmethod
+    def from_raw(cls, name: str, raw: T.Dict[str, T.Any]) -> SystemDependency:
+        name = raw.get('name', name)
+        version = raw.get('version')
+        version = version.split(',') if version is not None else []
+        vers: T.List[str] = []
+        for v in version:
+            v = v.strip()
+            if v[0] not in '><=':
+                v = f'>={v}'
+            vers.append(v)
+        optional = raw.get('optional', False)
+        feature = raw.get('feature')
+        # Everything else are overrides when certain features are enabled.
+        feature_overrides = {k: v for k, v in raw.items() if k not in {'name', 'version', 'optional', 'feature'}}
+        return cls(name, vers, optional, feature, feature_overrides)
+
+    def enabled(self, features: T.Set[str]) -> bool:
+        return self.feature is None or self.feature in features
+
 @dataclasses.dataclass
 class Dependency:
 
@@ -289,6 +322,7 @@ class Manifest:
     dependencies: T.Dict[str, Dependency]
     dev_dependencies: T.Dict[str, Dependency]
     build_dependencies: T.Dict[str, Dependency]
+    system_dependencies: T.Dict[str, SystemDependency] = dataclasses.field(init=False)
     lib: Library
     bin: T.List[Binary]
     test: T.List[Test]
@@ -300,6 +334,7 @@ class Manifest:
 
     def __post_init__(self) -> None:
         self.features.setdefault('default', [])
+        self.system_dependencies = {k: SystemDependency.from_raw(k, v) for k, v in self.package.metadata.get('system-deps', {}).items()}
 
 
 def _convert_manifest(raw_manifest: manifest.Manifest, subdir: str, path: str = '') -> Manifest:
@@ -563,8 +598,38 @@ def _create_dependencies(self, pkg: PackageState, build: builder.Builder) -> T.L
         for depname in pkg.required_deps:
             dep = pkg.manifest.dependencies[depname]
             ast += self._create_dependency(dep, build)
+        ast.append(build.assign(build.array([]), 'system_deps_args'))
+        for name, sys_dep in pkg.manifest.system_dependencies.items():
+            if sys_dep.enabled(pkg.features):
+                ast += self._create_system_dependency(name, sys_dep, build)
         return ast
 
+    def _create_system_dependency(self, name: str, dep: SystemDependency, build: builder.Builder) -> T.List[mparser.BaseNode]:
+        kw = {
+            'version': build.array([build.string(s) for s in dep.version]),
+            'required': build.bool(not dep.optional),
+        }
+        varname = f'{fixup_meson_varname(name)}_system_dep'
+        cfg = f'system_deps_have_{fixup_meson_varname(name)}'
+        return [
+            build.assign(
+                build.function(
+                    'dependency',
+                    [build.string(dep.name)],
+                    kw,
+                ),
+                varname,
+            ),
+            build.if_(
+                build.method('found', build.identifier(varname)), build.block([
+                    build.plusassign(
+                        build.array([build.string('--cfg'), build.string(cfg)]),
+                        'system_deps_args'
+                    ),
+                ])
+            ),
+        ]
+
     def _create_dependency(self, dep: Dependency, build: builder.Builder) -> T.List[mparser.BaseNode]:
         pkg = self._dep_package(dep)
         kw = {
@@ -654,10 +719,14 @@ def _create_lib(self, pkg: PackageState, build: builder.Builder, crate_type: man
                 dep_pkg = self._dep_package(dep)
                 dep_lib_name = dep_pkg.manifest.lib.name
                 dependency_map[build.string(fixup_meson_varname(dep_lib_name))] = build.string(name)
+        for name, sys_dep in pkg.manifest.system_dependencies.items():
+            if sys_dep.enabled(pkg.features):
+                dependencies.append(build.identifier(f'{fixup_meson_varname(name)}_system_dep'))
 
         rust_args: T.List[mparser.BaseNode] = [
             build.identifier('features_args'),
-            build.identifier(_extra_args_varname())
+            build.identifier(_extra_args_varname()),
+            build.identifier('system_deps_args'),
         ]
 
         dependencies.append(build.identifier(_extra_deps_varname()))

test cases/rust/26 cargo system deps/main.rs

@@ -0,0 +1,5 @@
+extern crate sub;
+
+pub fn main() {
+    sub::func();
+}

test cases/rust/26 cargo system deps/meson.build

@@ -0,0 +1,11 @@
+project('cargo system-deps', 'rust')
+
+glib = dependency('glib-2.0', required: false)
+if not glib.found()
+  error('MESON_SKIP_TEST: Need glib system dependency')
+endif
+
+sub_dep = dependency('sub-1-rs')
+exe = executable('main', 'main.rs', dependencies : sub_dep)
+test('main', exe)
+

test cases/rust/26 cargo system deps/subprojects/sub-1-rs.wrap

@@ -0,0 +1,2 @@
+[wrap-file]
+method = cargo

test cases/rust/26 cargo system deps/subprojects/sub-1-rs/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = 'sub'
+version = '1'
+
+[build-dependencies]
+system-deps = "6"
+
+[lib]
+name = "sub"
+path = "lib.rs"
+
+[package.metadata.system-deps]
+glib = { name = "glib-2.0", version=" 2.0 , 2.1 , <3 ", feature="default" }
+gobject = { name = "gobject-2.0", version=">=99", optional=true }
+notfound = { feature="notfound" }

test cases/rust/26 cargo system deps/subprojects/sub-1-rs/lib.rs

@@ -0,0 +1,15 @@
+extern "C" {
+    fn g_get_tmp_dir() -> *mut std::ffi::c_void;
+}
+
+#[cfg(system_deps_have_glib)]
+#[cfg(not(system_deps_have_gobject))]
+pub fn func() {
+    unsafe {
+        g_get_tmp_dir();
+    }
+}
+
+pub fn func1() {
+    func()
+}