[PATCH v2 2/2] checkpatch: 3 use-cases for --debug rx=1 option

[Jim Cromie <jim.cromie@gmail.com>]

Use the drx_print() helper in 3 cases inside code which counts macro
arg expansions.

$ scripts/checkpatch.pl --strict patch-1 --debug rx='##'
drx_print: 'arg ##' catenations
  >> Matched (`$&`): <_id##>
drx_print: 'arg ##' catenations
  >> Matched (`$&`): <_id##>
drx_print: '#|## arg' catenations
  >> Matched (`$&`): <##_model>
drx_print: '#|## arg' catenations
  >> Matched (`$&`): <##_model>

$ scripts/checkpatch.pl --strict patch-1 --debug rx='insp'
drx_print: -arg-inspections-
  >> Matched (`$&`): <__builtin_constant_p(cls>
  >> Capture 1 (`$1`): <__builtin_constant_p>

NB: see also the extended --debug key=1 facility:

$ scripts/checkpatch.pl --strict ../linux.git/pt-1 --debug foo=1
Unknown debug key 'foo', expecting: 'values possible type attr rx'

NB: I moved the 2 #|## strippers above the more complex macro, because
the latter caught one ## case that it needn't have.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 scripts/checkpatch.pl | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index c174e3bef2b2..240ddab17d89 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6078,9 +6078,17 @@ sub process {
 			        next if ($arg =~ /\.\.\./);
 			        next if ($arg =~ /^type$/i);
 				my $tmp_stmt = $define_stmt;
-				$tmp_stmt =~ s/\b(__must_be_array|offsetof|sizeof|sizeof_field|__stringify|typeof|__typeof__|__builtin\w+|typecheck\s*\(\s*$Type\s*,|\#+)\s*\(*\s*$arg\s*\)*\b//g;
-				$tmp_stmt =~ s/\#+\s*$arg\b//g;
-				$tmp_stmt =~ s/\b$arg\s*\#\#//g;
+
+				$tmp_stmt =~ s/\#+\s*$arg\b/drx_print("'#|## arg' catenations")/ge;
+				$tmp_stmt =~ s/\b$arg\s*\#\#/drx_print("'arg ##' catenations");/ge;
+				$tmp_stmt =~ s{
+					\b(__must_be_array|offsetof|sizeof|sizeof_field|
+					   __stringify|typeof|__typeof__|__builtin\w+|
+					   typecheck\s*\(\s*$Type\s*,|\#+)\s*\(*\s*$arg\s*\)*\b }
+				{
+					drx_print("-arg-inspections-");
+				}xge;
+
 				my $use_cnt = () = $tmp_stmt =~ /\b$arg\b/g;
 				if ($use_cnt > 1) {
 					CHK("MACRO_ARG_REUSE",
-- 
2.51.0