[PATCH] checkpatch: Add a --strict test for structs with bool member definitions

[Joe Perches]

A struct with a bool member can have different sizes on various
architectures because neither bool size nor alignment is standardized.

So emit a message on the use of bool in structs only in .h files and
not .c files.

There is the real possibility that this test could have a false positive
when a bool is declared as an automatic, so limit the test to .h files
where the only false positive is for declarations in static inline functions.

Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
 scripts/checkpatch.pl | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index e16d6713f236..24618dffc5cb 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6257,6 +6257,13 @@ sub process {
 			     "Avoid using bool as bitfield.  Prefer bool bitfields as unsigned int or u<8|16|32>\n" . $herecurr);
 		}
 
+# check for bool use in .h files
+		if ($realfile =~ /\.h$/ &&
+		    $sline =~ /^.\s+bool\s*$Ident\s*(?::\s*d+\s*)?;/) {
+			CHK("BOOL_MEMBER",
+			    "Avoid using bool structure members because of possible alignment issues - see: https://lkml.org/lkml/2017/11/21/384\n"; . $herecurr);
+		}
+
 # check for semaphores initialized locked
 		if ($line =~ /^.\s*sema_init.+,\W?0\W?\)/) {
 			WARN("CONSIDER_COMPLETION",
-- 
2.15.0