Interpreter: Set self.current_node during method/function calls

The current node is useful to pass as location kwarg to mlog.warning().
The node is not passed to InterpreterObject method arguments, and it's
easier to have it on the object than passing it through argument
everywhere.

mesonbuild/interpreterbase.py

@@ -320,6 +320,9 @@ class BreakRequest(BaseException):
 class InterpreterObject:
     def __init__(self):
         self.methods = {}
+        # Current node set during a method call. This can be used as location
+        # when printing a warning message during a method call.
+        self.current_node = None
 
     def method_call(self, method_name, args, kwargs):
         if method_name in self.methods:
@@ -366,6 +369,9 @@ class InterpreterBase:
         self.variables = {}
         self.argument_depth = 0
         self.current_lineno = -1
+        # Current node set during a function call. This can be used as location
+        # when printing a warning message during a method call.
+        self.current_node = None
 
     def load_root_meson_file(self):
         mesonfile = os.path.join(self.source_root, self.subdir, environment.build_filename)
@@ -759,6 +765,7 @@ The result of this is undefined and will become a hard error in a future Meson r
             if not getattr(func, 'no-args-flattening', False):
                 posargs = flatten(posargs)
 
+            self.current_node = node
             return func(node, posargs, kwargs)
         else:
             self.unknown_function_called(func_name)
@@ -795,6 +802,7 @@ The result of this is undefined and will become a hard error in a future Meson r
             return Disabler()
         if method_name == 'extract_objects':
             self.validate_extraction(obj.held_object)
+        obj.current_node = node
         return obj.method_call(method_name, args, kwargs)
 
     def bool_method_call(self, obj, method_name, args):