[PATCH v4 01/15] scripts: checkpatch: Add __aligned to the list of attribute notes

From: Marcelo Schmitt
Date: Sat Dec 16 2023 - 12:46:22 EST


Checkpatch presumes attributes marked with __aligned(alignment) are part
of a function declaration and throws a warning stating that those
compiler attributes should have an identifier name which is not correct.
Add __aligned compiler attributes to the list of attribute notes
so they don't cause warnings anymore.

Signed-off-by: Marcelo Schmitt <marcelo.schmitt@xxxxxxxxxx>
---
Any expression that evaluates to an integer that is a power of 2 can be
within __aligned parenthesis.
I can't see how we could use a regex to check code meets such constraint (if possible).

Some additional exotic uses of __aligned are:
drivers/net/wireless/quantenna/qtnfmac/bus.h:72: char bus_priv[] __aligned(sizeof(void *));
include/linux/netdevice.h:225:} __aligned(4 * sizeof(unsigned long));

The regex
__aligned\s*\(.*\)
seems to match all use cases.

We might not catch invalid arguments to __aligned, but it looks like making
checkpath confidently report those wouldn't be feasible anyway.

The patch that would trigger the mentioned warning in now
patch number 13 (iio: adc: Add support for AD7091R-8).

scripts/checkpatch.pl | 1 +
1 file changed, 1 insertion(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 25fdb7fda112..d56c98146da3 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -512,6 +512,7 @@ our $Attribute = qr{
__ro_after_init|
__kprobes|
$InitAttribute|
+ __aligned\s*\(.*\)|
____cacheline_aligned|
____cacheline_aligned_in_smp|
____cacheline_internodealigned_in_smp|
--
2.42.0