modules: rust: add dependencies() method to package object

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

5 files changed, 76 insertions, 11 deletions

diff --git a/docs/markdown/Rust-module.md b/docs/markdown/Rust-module.md
index 37ba59d8e..1acb9324b 100644
--- a/docs/markdown/Rust-module.md
+++ b/docs/markdown/Rust-module.md
@@ -269,6 +269,19 @@ Arguments:
 - `package_name`: (str, optional) Name of the package; not needed for the
   root package of a workspace
 
+Example usage:
+```meson
+rustmod = import('rust')
+cargo_ws = rustmod.workspace()
+pkg = cargo_ws.package()
+
+executable('my_app', 'src/main.rs',
+  dependencies: pkg.dependencies(),
+  rust_args: pkg.rust_args(),
+  rust_dependency_map: pkg.rust_dependency_map(),
+)
+```
+
 ### workspace.subproject()
 
 ```meson
@@ -353,6 +366,21 @@ dep_map = pkg.rust_dependency_map()
 
 Returns rust dependency mapping for this package.
 
+#### package.dependencies()
+
+```meson
+deps = pkg.dependencies(...)
+```
+
+Returns a list of dependency objects for all the dependencies required by this
+Rust package, including both Rust crate dependencies and system dependencies.
+The returned dependencies can be used directly in build target declarations.
+
+Keyword arguments:
+- `dependencies`: (`bool`, default: true) Whether to include regular Rust crate dependencies
+- `dev_dependencies`: (`bool`, default: false) Whether to include development dependencies (not yet implemented)
+- `system_dependencies`: (`bool`, default: true) Whether to include system dependencies
+
 ### Subprojects only
 
 #### subproject.dependency()
diff --git a/mesonbuild/modules/rust.py b/mesonbuild/modules/rust.py
index 5ba2a5f17..c1fcf049d 100644
--- a/mesonbuild/modules/rust.py
+++ b/mesonbuild/modules/rust.py
@@ -91,6 +91,16 @@ def no_spaces_validator(arg: T.Optional[T.Union[str, T.List]]) -> T.Optional[str
         return 'must not contain spaces due to limitations of rustdoc'
     return None
 
+def dep_to_system_dependency(dep: Dependency, depname: str) -> Dependency:
+    if not dep.found():
+        return dep
+    if not depname:
+        if not dep.name:
+            raise MesonException("rust.to_system_dependency() called with an unnamed dependency and no explicit name")
+        depname = dep.name
+    depname = re.sub(r'[^a-zA-Z0-9]', '_', depname)
+    rust_args = ['--cfg', f'system_deps_have_{depname}']
+    return RustSystemDependency(dep.version, compile_args=rust_args, ext_deps=[dep], name=dep.name)
 
 class RustWorkspace(ModuleObject):
     """Represents a Rust workspace, controlling the build of packages
@@ -218,6 +228,40 @@ class RustPackage(RustCrate):
 
     def __init__(self, rust_ws: RustWorkspace, package: cargo.PackageState) -> None:
         super().__init__(rust_ws, package)
+        self.methods.update({
+            'dependencies': self.dependencies_method,
+        })
+
+    @noPosargs
+    @typed_kwargs('package.dependencies',
+                  KwargInfo('dependencies', bool, default=True),
+                  KwargInfo('dev_dependencies', bool, default=False),
+                  KwargInfo('system_dependencies', bool, default=True))
+    def dependencies_method(self, state: ModuleState, args: T.List, kwargs: T.Dict[str, T.Any]) -> T.List[Dependency]:
+        """Returns the dependencies for this package."""
+        dependencies: T.List[Dependency] = []
+        cfg = self.package.cfg
+
+        if kwargs['dependencies']:
+            for dep_key, dep_pkg in cfg.dep_packages.items():
+                if dep_pkg.manifest.lib:
+                    # Get the dependency name for this package
+                    depname = dep_pkg.get_dependency_name(None)
+                    dependency = state.overridden_dependency(depname)
+                    dependencies.append(dependency)
+
+        if kwargs['dev_dependencies']:
+            raise MesonException('dev_dependencies is not implemented yet')
+
+        if kwargs['system_dependencies']:
+            for name, sys_dep in self.package.manifest.system_dependencies.items():
+                if sys_dep.enabled(cfg.features):
+                    # System dependencies use the original dependency name from Cargo.toml
+                    dependency = state.dependency(sys_dep.name, required=not sys_dep.optional,
+                                                  wanted=sys_dep.meson_version)
+                    dependencies.append(dep_to_system_dependency(dependency, name))
+
+        return dependencies
 
 
 class RustSubproject(RustCrate):
@@ -664,15 +708,7 @@ class RustModule(ExtensionModule):
     @noKwargs
     def to_system_dependency(self, state: ModuleState, args: T.Tuple[Dependency, T.Optional[str]], kwargs: TYPE_kwargs) -> Dependency:
         dep, depname = args
-        if not dep.found():
-            return dep
-        if not depname:
-            if not dep.name:
-                raise MesonException("rust.to_system_dependency() called with an unnamed dependency and no explicit name")
-            depname = dep.name
-        depname = re.sub(r'[^a-zA-Z0-9]', '_', depname)
-        rust_args = ['--cfg', f'system_deps_have_{depname}']
-        return RustSystemDependency(dep.version, compile_args=rust_args, ext_deps=[dep], name=dep.name)
+        return dep_to_system_dependency(dep, depname)
 
     @FeatureNew('rust.workspace', '1.11.0')
     @noPosargs
diff --git a/test cases/rust/31 rust.workspace package/meson.build b/test cases/rust/31 rust.workspace package/meson.build
index 5a9b44e41..ec17a00f5 100644
--- a/test cases/rust/31 rust.workspace package/meson.build
+++ b/test cases/rust/31 rust.workspace package/meson.build
@@ -28,7 +28,7 @@ assert(answer_rs.all_features() == ['default', 'large'])
 assert(answer_rs.features() == ['default', 'large'])
 
 e = executable('package-test', 'src/main.rs',
-  dependencies: [hello_rs.dependency(), answer_rs.dependency()],
+  dependencies: main_pkg.dependencies(),
   rust_args: main_pkg.rust_args(),
   rust_dependency_map: main_pkg.rust_dependency_map(),
 )
diff --git a/test cases/rust/32 rust.workspace workspace/meson.build b/test cases/rust/32 rust.workspace workspace/meson.build
index f42630b3d..63df7b1c4 100644
--- a/test cases/rust/32 rust.workspace workspace/meson.build
+++ b/test cases/rust/32 rust.workspace workspace/meson.build
@@ -30,7 +30,7 @@ assert(answer_rs.features() == ['default', 'large'])
 subdir('more')
 
 e = executable('workspace-test', 'src/main.rs',
-  dependencies: [hello_rs.dependency(), answer_rs.dependency(), more_dep],
+  dependencies: main_pkg.dependencies(),
   rust_args: main_pkg.rust_args(),
   rust_dependency_map: main_pkg.rust_dependency_map(),
 )
diff --git a/test cases/rust/32 rust.workspace workspace/more/meson.build b/test cases/rust/32 rust.workspace workspace/more/meson.build
index d7317a268..37ae51604 100644
--- a/test cases/rust/32 rust.workspace workspace/more/meson.build
+++ b/test cases/rust/32 rust.workspace workspace/more/meson.build
@@ -9,3 +9,4 @@ l = static_library('more', 'src/lib.rs',
   rust_dependency_map: more_pkg.rust_dependency_map(),
 )
 more_dep = declare_dependency(link_with: l)
+meson.override_dependency('more-0.1-rs', more_dep)