Cargo interpreter bugfixes

mesonbuild/cargo/interpreter.py

@@ -12,6 +12,7 @@
 from __future__ import annotations
 import dataclasses
 import functools
+import itertools
 import os
 import pathlib
 import collections
@@ -144,6 +145,8 @@ def get_lint_args(self, rustc: RustCompiler) -> T.List[str]:
             args.extend(lint.to_arguments(has_check_cfg))
 
         if has_check_cfg:
+            args.append('--check-cfg')
+            args.append('cfg(test)')
             for feature in self.manifest.features:
                 if feature != 'default':
                     args.append('--check-cfg')
@@ -426,6 +429,20 @@ def _prepare_package(self, pkg: PackageState) -> None:
         for condition, dependencies in pkg.manifest.target.items():
             if eval_cfg(condition, cfgs):
                 pkg.manifest.dependencies.update(dependencies)
+
+        # If you specify the optional dependency with the dep: prefix anywhere in the [features]
+        # table, that disables the implicit feature.
+        deps = set(feature[4:]
+                   for feature in itertools.chain.from_iterable(pkg.manifest.features.values())
+                   if feature.startswith('dep:'))
+        for name, dep in itertools.chain(pkg.manifest.dependencies.items(),
+                                         pkg.manifest.dev_dependencies.items(),
+                                         pkg.manifest.build_dependencies.items()):
+            if dep.optional and name not in deps:
+                pkg.manifest.features.setdefault(name, [])
+                pkg.manifest.features[name].append(f'dep:{name}')
+                deps.add(name)
+
         # Fetch required dependencies recursively.
         for depname, dep in pkg.manifest.dependencies.items():
             if not dep.optional:
@@ -497,9 +514,6 @@ def _enable_feature(self, pkg: PackageState, feature: str) -> None:
         if feature in cfg.features:
             return
         cfg.features.add(feature)
-        # A feature can also be a dependency.
-        if feature in pkg.manifest.dependencies:
-            self._add_dependency(pkg, feature)
         # Recurse on extra features and dependencies this feature pulls.
         # https://doc.rust-lang.org/cargo/reference/features.html#the-features-section
         for f in pkg.manifest.features.get(feature, []):

mesonbuild/cargo/manifest.py

@@ -442,8 +442,7 @@ def from_raw(cls, r: T.Union[raw.FromWorkspace, T.Dict[str, T.Dict[str, raw.Lint
                     settings = T.cast('raw.Lint', {'level': settings})
                 check_cfg = None
                 if name == 'unexpected_cfgs':
-                    # 'cfg(test)' is added automatically by cargo
-                    check_cfg = ['cfg(test)'] + settings.get('check-cfg', [])
+                    check_cfg = settings.get('check-cfg', [])
                 lints[name] = Lint(name=name,
                                    level=settings['level'],
                                    priority=settings.get('priority', 0),

unittests/cargotests.py

@@ -428,7 +428,7 @@ def test_cargo_toml_lints(self) -> None:
         self.assertEqual(manifest.lints[2].name, 'unexpected_cfgs')
         self.assertEqual(manifest.lints[2].level, 'deny')
         self.assertEqual(manifest.lints[2].priority, 0)
-        self.assertEqual(manifest.lints[2].check_cfg, ['cfg(test)', 'cfg(MESON)'])
+        self.assertEqual(manifest.lints[2].check_cfg, ['cfg(MESON)'])
 
     def test_cargo_toml_lints_to_args(self) -> None:
         with tempfile.TemporaryDirectory() as tmpdir:
@@ -444,8 +444,7 @@ def test_cargo_toml_lints_to_args(self) -> None:
         self.assertEqual(manifest.lints[1].to_arguments(True), ['-A', 'unknown_lints'])
         self.assertEqual(manifest.lints[2].to_arguments(False), ['-D', 'unexpected_cfgs'])
         self.assertEqual(manifest.lints[2].to_arguments(True),
-                         ['-D', 'unexpected_cfgs', '--check-cfg', 'cfg(test)',
-                          '--check-cfg', 'cfg(MESON)'])
+                         ['-D', 'unexpected_cfgs', '--check-cfg', 'cfg(MESON)'])
 
     def test_cargo_toml_dependencies(self) -> None:
         with tempfile.TemporaryDirectory() as tmpdir: