dependencyfallbacks: move required/disabled check to interpreter

The lookup code only has two callers. One of them is an internal caller
that never sets the `required` key, and the other is the interpreter.
Moving this code to the interpreter allows us to simplify the common
code, especially the types.

Author: dcbaker

mesonbuild/interpreter/dependencyfallbacks.py

@@ -4,7 +4,6 @@
 
 from __future__ import annotations
 
-from .interpreterobjects import extract_required_kwarg
 from .. import mlog
 from .. import dependencies
 from .. import build
@@ -311,14 +310,11 @@ def _get_candidates(self) -> T.List[T.Tuple[T.Callable[[TYPE_nkwargs, TYPE_nvar,
         return candidates
 
     def lookup(self, kwargs: TYPE_nkwargs, force_fallback: bool = False) -> Dependency:
-        mods = T.cast('T.List[str]', kwargs.get('modules', []))
+        mods = kwargs.get('modules', [])
         if mods:
             self._display_name += ' (modules: {})'.format(', '.join(str(i) for i in mods))
 
-        disabled, required, feature = extract_required_kwarg(kwargs, self.subproject)
-        if disabled:
-            mlog.log('Dependency', mlog.bold(self._display_name), 'skipped: feature', mlog.bold(feature), 'disabled')
-            return self._notfound_dependency()
+        required = kwargs.get('required', True)
 
         # Check if usage of the subproject fallback is forced
         wrap_mode = WrapMode.from_string(self.coredata.optstore.get_value_for(OptionKey('wrap_mode')))

mesonbuild/interpreter/interpreter.py

@@ -1774,8 +1774,20 @@ def func_dependency(self, node: mparser.BaseNode, args: T.Tuple[T.List[str]], kw
         df = DependencyFallbacksHolder(self, names, kwargs['allow_fallback'], default_options)
         df.set_fallback(kwargs['fallback'])
         not_found_message = kwargs['not_found_message']
+
+        disabled, required, feature = extract_required_kwarg(kwargs, self.subproject)
+        if disabled:
+            name = names[0]
+            if kwargs['modules']:
+                name = name + '(modules: {})'.format(', '.join(kwargs['modules']))
+            mlog.log('Dependency', mlog.bold(name), 'skipped: feature', mlog.bold(feature), 'disabled')
+            return dependencies.NotFoundDependency(names[0], self.environment)
+
+        nkwargs = T.cast('dependencies.base.DependencyObjectKWs', kwargs.copy())
+        nkwargs['required'] = required  # to replace a possible UserFeatureOption with a bool
+
         try:
-            d = df.lookup(kwargs)
+            d = df.lookup(nkwargs)
         except Exception:
             if not_found_message:
                 self.message_impl([not_found_message])