[PATCH 10/10] checkpatch: suggest nonnull attribute conversion

[Dmitry Ilvokhin <d@ilvokhin.com>]

The kernel provides the __nonnull_args() macro as the preferred form for
marking pointer arguments as non-NULL. Add a check suggesting the macro
over the raw __attribute__((nonnull)) spelling, consistent with the
existing attribute conversion suggestions.

Examples:

  WARNING: Prefer __nonnull_args(1, 2) over __attribute__((nonnull(1, 2)))
  #11: FILE: drivers/soc/aspeed/aspeed-lpc-snoop.c:230:
  +__attribute__((nonnull(1, 2)))

  WARNING: Prefer __nonnull_args() over __attribute__((nonnull))
  #11: FILE: drivers/soc/aspeed/aspeed-lpc-snoop.c:283:
  +__attribute__((nonnull))

Signed-off-by: Dmitry Ilvokhin <d@ilvokhin.com>
---
 scripts/checkpatch.pl | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index c9840f5219c2..e696fcd02337 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6856,6 +6856,7 @@ sub process {
 				"no_caller_saved_registers"	=> "__no_caller_saved_registers",
 				"noclone"			=> "__noclone",
 				"noinline"			=> "noinline",
+				"nonnull"			=> "__nonnull_args",
 				"nonstring"			=> "__nonstring",
 				"noreturn"			=> "__noreturn",
 				"packed"			=> "__packed",
@@ -6876,6 +6877,8 @@ sub process {
 					if ($curr_attr eq "format" && $params) {
 						$params =~ /^\s*\(\s*(\w+)\s*,\s*(.*)/;
 						$new = "__$1\($2";
+					} elsif ($curr_attr eq "nonnull" && $params eq "") {
+						$new = "$new()";
 					} else {
 						$new = "$new$params";
 					}
-- 
2.53.0-Meta