[PATCH v6 4/4] checkpatch: warn on empty rust doc comments

[Hridesh MG <hridesh699@gmail.com>]

Add a check to warn if there are consecutive empty `///` lines in rust
files.

Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1109
Signed-off-by: Hridesh MG <hridesh699@gmail.com>
---
v2: https://lore.kernel.org/rust-for-linux/7877d23adba22e2f89a61efc129ecf1b0627510b.1726072795.git.hridesh699@gmail.com/
  - new patch
v3: https://lore.kernel.org/rust-for-linux/bf6544faba2b53ce901b2e031f3d944babcc7018.1727606659.git.hridesh699@gmail.com/
  - no changes
v6:
  - added --fix support which deletes the unnecessary line
---
 scripts/checkpatch.pl | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index c390a9926cd5..baadc345bf87 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3911,6 +3911,15 @@ sub process {
 					$fixed[$fixlinenr] =~ s/\b$header\b/ucfirst(lc($header)) . 's'/e;
 				}
 			}
+
+			# check for consecutive empty rustdoc lines
+			if ($rawline =~ /^\+\s*\/\/\/$/ && $prevrawline =~ /^\+?\s*\/\/\/$/) {
+				if (WARN("RUST_DOC_EMPTY",
+				         "avoid using consecutive empty rustdoc comments\n" . $herecurr) &&
+				    $fix) {
+					fix_delete_line($fixlinenr, $rawline);
+				}
+			}
 		}
 
 # check we are in a valid source file C or perl if not then ignore this hunk
-- 
2.46.1