1 files changed, 56 insertions, 0 deletions
diff --git a/mesonbuild/interpreterbase/helpers.py b/mesonbuild/interpreterbase/helpers.py
new file mode 100644
index 0000000..2196b4e
--- /dev/null
+++ b/mesonbuild/interpreterbase/helpers.py
@@ -0,0 +1,56 @@
+# Copyright 2013-2021 The Meson development team
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from __future__ import annotations
+
+from .. import mesonlib, mparser
+from .exceptions import InterpreterException
+
+import collections.abc
+import typing as T
+
+if T.TYPE_CHECKING:
+    from .baseobjects import TYPE_var, TYPE_kwargs
+
+def flatten(args: T.Union['TYPE_var', T.List['TYPE_var']]) -> T.List['TYPE_var']:
+    if isinstance(args, mparser.StringNode):
+        assert isinstance(args.value, str)
+        return [args.value]
+    if not isinstance(args, collections.abc.Sequence):
+        return [args]
+    result: T.List['TYPE_var'] = []
+    for a in args:
+        if isinstance(a, list):
+            rest = flatten(a)
+            result = result + rest
+        elif isinstance(a, mparser.StringNode):
+            result.append(a.value)
+        else:
+            result.append(a)
+    return result
+
+def resolve_second_level_holders(args: T.List['TYPE_var'], kwargs: 'TYPE_kwargs') -> T.Tuple[T.List['TYPE_var'], 'TYPE_kwargs']:
+    def resolver(arg: 'TYPE_var') -> 'TYPE_var':
+        if isinstance(arg, list):
+            return [resolver(x) for x in arg]
+        if isinstance(arg, dict):
+            return {k: resolver(v) for k, v in arg.items()}
+        if isinstance(arg, mesonlib.SecondLevelHolder):
+            return arg.get_default_object()
+        return arg
+    return [resolver(x) for x in args], {k: resolver(v) for k, v in kwargs.items()}
+
+def default_resolve_key(key: mparser.BaseNode) -> str:
+    if not isinstance(key, mparser.IdNode):
+        raise InterpreterException('Invalid kwargs format.')
+    return key.value