[PATCH] kernel-doc: validate function prototype names

From: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
To: Jonathan Corbet <corbet@lwn.net>,
	Linux Media Mailing List <linux-media@vger.kernel.org>
Cc: linuxarm@huawei.com, mauro.chehab@huawei.com,
	Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] kernel-doc: validate function prototype names
Date: Fri, 23 Oct 2020 09:34:10 +0200	[thread overview]
Message-ID: <b5c62d6251516d9d87e1fb0746447612501b7fe3.1603438441.git.mchehab+huawei@kernel.org> (raw)

Kernel-doc currently expects that the kernel-doc markup to come
just before the function prototype. Yet, if it find things like:

	/**
	 * refcount_add - add a value to a refcount
	 * @i: the value to add to the refcount
	 * @r: the refcount
	 */
	static inline void __refcount_add(int i, refcount_t *r, int *oldp);
	static inline void refcount_add(int i, refcount_t *r);

Kernel-doc will do the wrong thing:

	foobar.h:6: warning: Function parameter or member 'oldp' not described in '__refcount_add'
	.. c:function:: void __refcount_add (int i, refcount_t *r, int *oldp)

	   add a value to a refcount

	**Parameters**

	``int i``
	  the value to add to the refcount

	``refcount_t *r``
	  the refcount

	``int *oldp``
	  *undescribed*

Basically, it will document "__refcount_add" with the kernel-doc
markup for refcount_add.

If both functions have the same arguments, this won't even
produce any warning!

Add a logic to check function identifiers, warning about
wrong identifiers and not documenting them.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 scripts/kernel-doc | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/scripts/kernel-doc b/scripts/kernel-doc
index 99cd8418ff8a..c879e69262dd 100755
--- a/scripts/kernel-doc
+++ b/scripts/kernel-doc
@@ -382,6 +382,9 @@ my $inline_doc_state;
 # 'function', 'struct', 'union', 'enum', 'typedef'
 my $decl_type;
 
+# On functions, this should match the name of the function
+my $identifier;
+
 my $doc_start = '^/\*\*\s*$'; # Allow whitespace at end of comment start.
 my $doc_end = '\*/';
 my $doc_com = '\s*\*\s*';
@@ -1785,6 +1788,11 @@ sub dump_function($$) {
 	$declaration_name = $2;
 	my $args = $3;
 
+	if ($identifier ne $declaration_name) {
+	    print STDERR "${file}:$.: warning: expecting prototype for function $identifier. Prototype was for function $declaration_name instead\n";
+	    return;
+	}
+
 	create_parameterlist($args, ',', $file, $declaration_name);
     } else {
 	print STDERR "${file}:$.: warning: cannot understand function prototype: '$prototype'\n";
@@ -2036,7 +2044,6 @@ sub process_normal() {
 #
 sub process_name($$) {
     my $file = shift;
-    my $identifier;
     my $descr;
 
     if (/$doc_block/o) {
-- 
2.26.2

