1 files changed, 118 insertions, 0 deletions
diff --git a/meson/mesonbuild/interpreterbase/helpers.py b/meson/mesonbuild/interpreterbase/helpers.py
new file mode 100644
index 000000000..235257795
--- /dev/null
+++ b/meson/mesonbuild/interpreterbase/helpers.py
@@ -0,0 +1,118 @@
+# 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 .. import mesonlib, mparser, mlog
+from .exceptions import InvalidArguments, 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 check_stringlist(a: T.Any, msg: str = 'Arguments must be strings.') -> None:
+    if not isinstance(a, list):
+        mlog.debug('Not a list:', str(a))
+        raise InvalidArguments('Argument not a list.')
+    if not all(isinstance(s, str) for s in a):
+        mlog.debug('Element not a string:', str(a))
+        raise InvalidArguments(msg)
+
+def default_resolve_key(key: mparser.BaseNode) -> str:
+    if not isinstance(key, mparser.IdNode):
+        raise InterpreterException('Invalid kwargs format.')
+    return key.value
+
+def get_callee_args(wrapped_args: T.Sequence[T.Any], want_subproject: bool = False) -> T.Tuple[T.Any, mparser.BaseNode, T.List['TYPE_var'], 'TYPE_kwargs', T.Optional[str]]:
+    s = wrapped_args[0]
+    n = len(wrapped_args)
+    # Raise an error if the codepaths are not there
+    subproject = None  # type: T.Optional[str]
+    if want_subproject and n == 2:
+        if hasattr(s, 'subproject'):
+            # Interpreter base types have 2 args: self, node
+            node = wrapped_args[1]
+            # args and kwargs are inside the node
+            args = None
+            kwargs = None
+            subproject = s.subproject
+        elif hasattr(wrapped_args[1], 'subproject'):
+            # Module objects have 2 args: self, interpreter
+            node = wrapped_args[1].current_node
+            # args and kwargs are inside the node
+            args = None
+            kwargs = None
+            subproject = wrapped_args[1].subproject
+        else:
+            raise AssertionError(f'Unknown args: {wrapped_args!r}')
+    elif n == 3:
+        # Methods on objects (*Holder, MesonMain, etc) have 3 args: self, args, kwargs
+        node = s.current_node
+        args = wrapped_args[1]
+        kwargs = wrapped_args[2]
+        if want_subproject:
+            if hasattr(s, 'subproject'):
+                subproject = s.subproject
+            elif hasattr(s, 'interpreter'):
+                subproject = s.interpreter.subproject
+    elif n == 4:
+        # Meson functions have 4 args: self, node, args, kwargs
+        # Module functions have 4 args: self, state, args, kwargs
+        from .interpreterbase import InterpreterBase  # TODO: refactor to avoid this import
+        if isinstance(s, InterpreterBase):
+            node = wrapped_args[1]
+        else:
+            node = wrapped_args[1].current_node
+        args = wrapped_args[2]
+        kwargs = wrapped_args[3]
+        if want_subproject:
+            if isinstance(s, InterpreterBase):
+                subproject = s.subproject
+            else:
+                subproject = wrapped_args[1].subproject
+    else:
+        raise AssertionError(f'Unknown args: {wrapped_args!r}')
+    # Sometimes interpreter methods are called internally with None instead of
+    # empty list/dict
+    args = args if args is not None else []
+    kwargs = kwargs if kwargs is not None else {}
+    return s, node, args, kwargs, subproject