Store filename in node location

Warnings have a location node object (with subdir and lineno
attributes), which is passed as a location: kwarg to mlog.warning() and
formatted in _log_error().

Re-purpose the subdir attribute (path relative to the source root dir,
with an implied filename of 'meson.build'), which is stored into the
node by parser(), to contain a pathname.

(Properly I should rename 'subdir' -> 'file' everywhere, but that's a
lot of churn just to see if this works)

Notes:
The warning location node may also have a colno attribute, which is
currently ignored by _log_error().

We can't currently issue warnings with locations in meson_options.txt
because the filename isn't part of the location (as it's assumed to be
'meson.build).

1 files changed, 1 insertions, 1 deletions

diff --git a/mesonbuild/optinterpreter.py b/mesonbuild/optinterpreter.py
index 2632b31..fd0a8c9 100644
--- a/mesonbuild/optinterpreter.py
+++ b/mesonbuild/optinterpreter.py
@@ -140,7 +140,7 @@ class OptionInterpreter:
     def process(self, option_file):
         try:
             with open(option_file, 'r', encoding='utf8') as f:
-                ast = mparser.Parser(f.read(), '').parse()
+                ast = mparser.Parser(f.read(), option_file).parse()
         except mesonlib.MesonException as me:
             me.file = option_file
             raise me