propagate the most accurate node to error messages

During evaluation of codeblocks, we start off with an iteration of
nodes, and then while evaluating them we may update the global
self.current_node context. When catching and formatting errors, we
didn't take into account that the node might be updated from the
original top-level iteration.

Switch to formatting errors using self.current_node instead, to ensure
we can point at the likely most-accurate actual cause of an error.

Also update the current node in a few more places, so that function
calls always see the function call as the current node, even if the most
recently parsed node was an argument to the function call.

Fixes #11643

1 files changed, 6 insertions, 3 deletions

diff --git a/mesonbuild/interpreterbase/interpreterbase.py b/mesonbuild/interpreterbase/interpreterbase.py
index 61b3f90..b1d0779 100644
--- a/mesonbuild/interpreterbase/interpreterbase.py
+++ b/mesonbuild/interpreterbase/interpreterbase.py
@@ -183,8 +183,9 @@ class InterpreterBase:
             except Exception as e:
                 if getattr(e, 'lineno', None) is None:
                     # We are doing the equivalent to setattr here and mypy does not like it
-                    e.lineno = cur.lineno                                                             # type: ignore
-                    e.colno = cur.colno                                                               # type: ignore
+                    # NOTE: self.current_node is continually updated during processing
+                    e.lineno = self.current_node.lineno                                               # type: ignore
+                    e.colno = self.current_node.colno                                                 # type: ignore
                     e.file = os.path.join(self.source_root, self.subdir, environment.build_filename)  # type: ignore
                 raise e
             i += 1 # In THE FUTURE jump over blocks and stuff.
@@ -516,6 +517,7 @@ class InterpreterBase:
                 func_args = flatten(posargs)
             if not getattr(func, 'no-second-level-holder-flattening', False):
                 func_args, kwargs = resolve_second_level_holders(func_args, kwargs)
+            self.current_node = node
             res = func(node, func_args, kwargs)
             return self._holderify(res) if res is not None else None
         else:
@@ -544,7 +546,7 @@ class InterpreterBase:
                 self.validate_extraction(obj.held_object)
             elif not isinstance(obj, Disabler):
                 raise InvalidArguments(f'Invalid operation "extract_objects" on {object_display_name} of type {type(obj).__name__}')
-        obj.current_node = node
+        obj.current_node = self.current_node = node
         res = obj.method_call(method_name, args, kwargs)
         return self._holderify(res) if res is not None else None
 
@@ -598,6 +600,7 @@ class InterpreterBase:
             reduced_val = self.evaluate_statement(val)
             if reduced_val is None:
                 raise InvalidArguments(f'Value of key {reduced_key} is void.')
+            self.current_node = key
             if duplicate_key_error and reduced_key in reduced_kw:
                 raise InvalidArguments(duplicate_key_error.format(reduced_key))
             reduced_kw[reduced_key] = reduced_val