Re: [PATCH mlx5-next v4 1/4] PCI: Add sysfs callback to allow MSI-X table size change of SR-IOV VFs

[Joe Perches <joe@perches.com>]

On Tue, 2021-01-26 at 08:01 +0200, Leon Romanovsky wrote:
> On Mon, Jan 25, 2021 at 01:52:29PM -0800, Jakub Kicinski wrote:
> > On Sun, 24 Jan 2021 15:11:16 +0200 Leon Romanovsky wrote:
> > > +static int pci_enable_vfs_overlay(struct pci_dev *dev) { return 0; }
> > > +static void pci_disable_vfs_overlay(struct pci_dev *dev) {}
> > 
> > s/static /static inline /
> 
> Thanks a lot, I think that we should extend checkpatch.pl to catch such
> mistakes.

Who is this "we" you refer to? ;)

> How hard is it to extend checkpatch.pl to do regexp and warn if in *.h file
> someone declared function with implementation but didn't add "inline" word?

Something like this seems reasonable and catches these instances in
include/linux/*.h

$ ./scripts/checkpatch.pl -f include/linux/*.h --types=static_inline --terse --nosummary
include/linux/dma-mapping.h:203: WARNING: static function definition might be better as static inline
include/linux/genl_magic_func.h:55: WARNING: static function definition might be better as static inline
include/linux/genl_magic_func.h:78: WARNING: static function definition might be better as static inline
include/linux/kernel.h:670: WARNING: static function definition might be better as static inline
include/linux/kprobes.h:213: WARNING: static function definition might be better as static inline
include/linux/kprobes.h:231: WARNING: static function definition might be better as static inline
include/linux/kprobes.h:511: WARNING: static function definition might be better as static inline
include/linux/skb_array.h:185: WARNING: static function definition might be better as static inline
include/linux/slab.h:606: WARNING: static function definition might be better as static inline
include/linux/stop_machine.h:62: WARNING: static function definition might be better as static inline
include/linux/vmw_vmci_defs.h:850: WARNING: static function definition might be better as static inline
include/linux/zstd.h:95: WARNING: static function definition might be better as static inline
include/linux/zstd.h:106: WARNING: static function definition might be better as static inline

A false positive exists when __must_check is used between
static and inline.  It's an unusual and IMO not a preferred use.
---
 scripts/checkpatch.pl | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 4f8494527139..0ac366481962 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -4451,6 +4451,18 @@ sub process {
 			}
 		}
 
+# check for static function definitions without inline in .h files
+# only works for static in column 1 and avoids multiline macro definitions
+		if ($realfile =~ /\.h$/ &&
+		    defined($stat) &&
+		    $stat =~ /^\+static(?!\s+(?:$Inline|union|struct))\b.*\{.*\}\s*$/s &&
+		    $line =~ /^\+static(?!\s+(?:$Inline|union|struct))\b/ &&
+		    $line !~ /\\$/) {
+			WARN("STATIC_INLINE",
+			     "static function definition might be better as static inline\n" .
+				$herecurr);
+		}
+
 # check for non-global char *foo[] = {"bar", ...} declarations.
 		if ($line =~ /^.\s+(?:static\s+|const\s+)?char\s+\*\s*\w+\s*\[\s*\]\s*=\s*\{/) {
 			WARN("STATIC_CONST_CHAR_ARRAY",