docs: kdoc: fix duplicate section warning message

The python version of the kernel-doc parser emits some strange warnings
with just a line number in certain cases:

$ ./scripts/kernel-doc -Wall -none 'include/linux/virtio_config.h'
Warning: 174
Warning: 184
Warning: 190
Warning: include/linux/virtio_config.h:226 No description found for return value of '__virtio_test_bit'
Warning: include/linux/virtio_config.h:259 No description found for return value of 'virtio_has_feature'
Warning: include/linux/virtio_config.h:283 No description found for return value of 'virtio_has_dma_quirk'
Warning: include/linux/virtio_config.h:392 No description found for return value of 'virtqueue_set_affinity'

I eventually tracked this down to the lone call of emit_msg() in the
KernelEntry class, which looks like:

  self.emit_msg(self.new_start_line, f"duplicate section name '{name}'\n")

This looks like all the other emit_msg calls. Unfortunately, the definition
within the KernelEntry class takes only a message parameter and not a line
number. The intended message is passed as the warning!

Pass the filename to the KernelEntry class, and use this to build the log
message in the same way as the KernelDoc class does.

To avoid future errors, mark the warning parameter for both emit_msg
definitions as a keyword-only argument. This will prevent accidentally
passing a string as the warning parameter in the future.

Also fix the call in dump_section to avoid an unnecessary additional
newline.

Fixes: e3b42e94cf10 ("scripts/lib/kdoc/kdoc_parser.py: move kernel entry to a class")
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20251030-jk-fix-kernel-doc-duplicate-return-warning-v2-1-ec4b5c662881@intel.com>

1 files changed, 10 insertions, 6 deletions

diff --git a/scripts/lib/kdoc/kdoc_parser.py b/scripts/lib/kdoc/kdoc_parser.py
index 6e5c115cbdf3..ee1a4ea6e725 100644
--- a/scripts/lib/kdoc/kdoc_parser.py
+++ b/scripts/lib/kdoc/kdoc_parser.py
@@ -275,6 +275,8 @@ class KernelEntry:
 
         self.leading_space = None
 
+        self.fname = fname
+
         # State flags
         self.brcount = 0
         self.declaration_start_line = ln + 1
@@ -289,9 +291,11 @@ class KernelEntry:
         return '\n'.join(self._contents) + '\n'
 
     # TODO: rename to emit_message after removal of kernel-doc.pl
-    def emit_msg(self, log_msg, warning=True):
+    def emit_msg(self, ln, msg, *, warning=True):
         """Emit a message"""
 
+        log_msg = f"{self.fname}:{ln} {msg}"
+
         if not warning:
             self.config.log.info(log_msg)
             return
@@ -337,7 +341,7 @@ class KernelEntry:
                 # Only warn on user-specified duplicate section names
                 if name != SECTION_DEFAULT:
                     self.emit_msg(self.new_start_line,
-                                  f"duplicate section name '{name}'\n")
+                                  f"duplicate section name '{name}'")
                 # Treat as a new paragraph - add a blank line
                 self.sections[name] += '\n' + contents
             else:
@@ -393,15 +397,15 @@ class KernelDoc:
                           'Python 3.7 or later is required for correct results')
             python_warning = True
 
-    def emit_msg(self, ln, msg, warning=True):
+    def emit_msg(self, ln, msg, *, warning=True):
         """Emit a message"""
 
-        log_msg = f"{self.fname}:{ln} {msg}"
-
         if self.entry:
-            self.entry.emit_msg(log_msg, warning)
+            self.entry.emit_msg(ln, msg, warning=warning)
             return
 
+        log_msg = f"{self.fname}:{ln} {msg}"
+
         if warning:
             self.config.log.warning(log_msg)
         else: