docs: c_lex: setup a logger to report tokenizer issues

Report file that has issues detected via CMatch and CTokenizer.

This is done by setting up a logger that will be overriden by
kdoc_parser, when used on it.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <903ad83ae176196a50444e66177a4f5bcdef5199.1773770483.git.mchehab+huawei@kernel.org>

tools/lib/python/kdoc/c_lex.py

@@ -22,6 +22,22 @@ from .kdoc_re import KernRe
 
 log = logging.getLogger(__name__)
 
+def tokenizer_set_log(logger, prefix = ""):
+    """
+    Replace the module‑level logger with a LoggerAdapter that
+    prepends *prefix* to every message.
+    """
+    global log
+
+    class PrefixAdapter(logging.LoggerAdapter):
+        """
+        Ancillary class to set prefix on all message logs.
+        """
+        def process(self, msg, kwargs):
+            return f"{prefix}{msg}", kwargs
+
+    # Wrap the provided logger in our adapter
+    log = PrefixAdapter(logger, {"prefix": prefix})
 
 class CToken():
     """

tools/lib/python/kdoc/kdoc_parser.py

@@ -13,7 +13,7 @@ import sys
 import re
 from pprint import pformat
 
-from kdoc.c_lex import CTokenizer
+from kdoc.c_lex import CTokenizer, tokenizer_set_log
 from kdoc.kdoc_re import KernRe
 from kdoc.kdoc_item import KdocItem
 
@@ -253,6 +253,8 @@ class KernelDoc:
         self.config = config
         self.xforms = xforms
 
+        tokenizer_set_log(self.config.log, f"{self.fname}: CMatch: ")
+
         # Initial state for the state machines
         self.state = state.NORMAL