lint/checkpatch.pl: Update to v5.18-2 lines related to "CONFIG_"

Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Change-Id: I8589d053871ad9ac64ae2f8fc380710be8e4556b
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63576
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin L Roth <martinroth@google.com>
diff --git a/util/lint/checkpatch.pl b/util/lint/checkpatch.pl
index a67e6b0..6defb99 100755
--- a/util/lint/checkpatch.pl
+++ b/util/lint/checkpatch.pl
@@ -71,6 +71,7 @@
 my $allow_c99_comments = 1;
 my $git_command ='git'; # coreboot
 my $tabsize = 8;
+my ${CONFIG_} = "CONFIG_";
 # For coreboot jenkins
 # If taint mode is enabled, Untaint the path - files must be in /bin, /usr/bin or /usr/local/bin
 if ( ${^TAINT} ) {
@@ -141,6 +142,8 @@
   --typedefsfile             Read additional types from this file
   --color[=WHEN]             Use colors 'always', 'never', or only when output
                              is a terminal ('auto'). Default is 'auto'.
+  --kconfig-prefix=WORD      use WORD as a prefix for Kconfig symbols (default
+                             ${CONFIG_})
   -h, --help, --version      display this help and exit
 
 When FILE is - read standard input.
@@ -327,6 +330,7 @@
 	'color=s'	=> \$color,
 	'no-color'	=> \$color,	#keep old behaviors of -nocolor
 	'nocolor'	=> \$color,	#keep old behaviors of -nocolor
+	'kconfig-prefix=s'	=> \${CONFIG_},
 	'h|help'	=> \$help,
 	'version'	=> \$help
 ) or $help = 2;
@@ -2382,6 +2386,28 @@
 	return length(expand_tabs(substr($line, 0, $last_openparen))) + 1;
 }
 
+sub get_raw_comment {
+	my ($line, $rawline) = @_;
+	my $comment = '';
+
+	for my $i (0 .. (length($line) - 1)) {
+		if (substr($line, $i, 1) eq "$;") {
+			$comment .= substr($rawline, $i, 1);
+		}
+	}
+
+	return $comment;
+}
+
+sub exclude_global_initialisers {
+	my ($realfile) = @_;
+
+	# Do not check for BPF programs (tools/testing/selftests/bpf/progs/*.c, samples/bpf/*_kern.c, *.bpf.c).
+	return $realfile =~ m@^tools/testing/selftests/bpf/progs/.*\.c$@ ||
+		$realfile =~ m@^samples/bpf/.*_kern\.c$@ ||
+		$realfile =~ m@/bpf/.*\.bpf\.c$@;
+}
+
 sub process {
 	my $filename = shift;
 
@@ -2538,6 +2564,7 @@
 		$sline =~ s/$;/ /g;	#with comments as spaces
 
 		my $rawline = $rawlines[$linenr - 1];
+		my $raw_comment = get_raw_comment($line, $rawline);
 
 # check if it's a mode change, rename or start of a patch
 		if (!$in_commit_log &&
@@ -3016,51 +3043,47 @@
 		    # Kconfig supports named choices), so use a word boundary
 		    # (\b) rather than a whitespace character (\s)
 		    $line =~ /^\+\s*(?:config|menuconfig|choice)\b/) {
-			my $length = 0;
-			my $cnt = $realcnt;
-			my $ln = $linenr + 1;
-			my $f;
-			my $is_start = 0;
-			my $is_end = 0;
-			for (; $cnt > 0 && defined $lines[$ln - 1]; $ln++) {
-				$f = $lines[$ln - 1];
-				$cnt-- if ($lines[$ln - 1] !~ /^-/);
-				$is_end = $lines[$ln - 1] =~ /^\+/;
+			my $ln = $linenr;
+			my $needs_help = 0;
+			my $has_help = 0;
+			my $help_length = 0;
+			while (defined $lines[$ln]) {
+				my $f = $lines[$ln++];
 
 				next if ($f =~ /^-/);
-				last if (!$file && $f =~ /^\@\@/);
+				last if ($f !~ /^[\+ ]/);	# !patch context
 
-				if ($lines[$ln - 1] =~ /^\+\s*(?:bool|tristate|prompt)\s*["']/) {
-					$is_start = 1;
-				} elsif ($lines[$ln - 1] =~ /^\+\s*(?:help|---help---)\s*$/) {
-					if ($lines[$ln - 1] =~ "---help---") {
-						WARN("CONFIG_DESCRIPTION",
-						     "prefer 'help' over '---help---' for new help texts\n" . $herecurr);
-					}
-					$length = -1;
+				if ($f =~ /^\+\s*(?:bool|tristate|prompt)\s*["']/) {
+					$needs_help = 1;
+					next;
+				}
+				if ($f =~ /^\+\s*help\s*$/) {
+					$has_help = 1;
+					next;
 				}
 
-				$f =~ s/^.//;
-				$f =~ s/#.*//;
-				$f =~ s/^\s+//;
-				next if ($f =~ /^$/);
+				$f =~ s/^.//;	# strip patch context [+ ]
+				$f =~ s/#.*//;	# strip # directives
+				$f =~ s/^\s+//;	# strip leading blanks
+				next if ($f =~ /^$/);	# skip blank lines
 
+				# At the end of this Kconfig block:
 				# This only checks context lines in the patch
 				# and so hopefully shouldn't trigger false
 				# positives, even though some of these are
 				# common words in help texts
-				if ($f =~ /^\s*(?:config|menuconfig|choice|endchoice|
-						  if|endif|menu|endmenu|source)\b/x) {
-					$is_end = 1;
+				if ($f =~ /^(?:config|menuconfig|choice|endchoice|
+					       if|endif|menu|endmenu|source)\b/x) {
 					last;
 				}
-				$length++;
+				$help_length++ if ($has_help);
 			}
-			if ($is_start && $is_end && $length < $min_conf_desc_length) {
+			if ($needs_help &&
+			    $help_length < $min_conf_desc_length) {
+				my $stat_real = get_stat_real($linenr, $ln - 1);
 				WARN("CONFIG_DESCRIPTION",
-				     "please write a paragraph that describes the config symbol fully\n" . $herecurr);
+				     "please write a help paragraph that fully describes the config symbol\n" . "$here\n$stat_real\n");
 			}
-			#print "is_start<$is_start> is_end<$is_end> length<$length>\n";
 		}
 
 # check for MAINTAINERS entries that don't have the right form
@@ -6388,28 +6411,41 @@
 			}
 		}
 
-# check for case / default statements not preceded by break/fallthrough/switch
-		if ($line =~ /^.\s*(?:case\s+(?:$Ident|$Constant)\s*|default):/) {
-			my $has_break = 0;
-			my $has_statement = 0;
-			my $count = 0;
-			my $prevline = $linenr;
-			while ($prevline > 1 && ($file || $count < 3) && !$has_break) {
-				$prevline--;
-				my $rline = $rawlines[$prevline - 1];
-				my $fline = $lines[$prevline - 1];
-				last if ($fline =~ /^\@\@/);
-				next if ($fline =~ /^\-/);
-				next if ($fline =~ /^.(?:\s*(?:case\s+(?:$Ident|$Constant)[\s$;]*|default):[\s$;]*)*$/);
-				$has_break = 1 if ($rline =~ /fall[\s_-]*(through|thru)/i);
-				next if ($fline =~ /^.[\s$;]*$/);
-				$has_statement = 1;
-				$count++;
-				$has_break = 1 if ($fline =~ /\bswitch\b|\b(?:break\s*;[\s$;]*$|exit\s*\(\b|return\b|goto\b|continue\b)/);
+# check for IS_ENABLED() without CONFIG_<FOO> ($rawline for comments too)
+		if ($rawline =~ /\bIS_ENABLED\s*\(\s*(\w+)\s*\)/ && $1 !~ /^${CONFIG_}/) {
+			WARN("IS_ENABLED_CONFIG",
+			     "IS_ENABLED($1) is normally used as IS_ENABLED(${CONFIG_}$1)\n" . $herecurr);
+		}
+
+# check for #if defined CONFIG_<FOO> || defined CONFIG_<FOO>_MODULE
+		if ($line =~ /^\+\s*#\s*if\s+defined(?:\s*\(?\s*|\s+)(${CONFIG_}[A-Z_]+)\s*\)?\s*\|\|\s*defined(?:\s*\(?\s*|\s+)\1_MODULE\s*\)?\s*$/) {
+			my $config = $1;
+			if (WARN("PREFER_IS_ENABLED",
+				 "Prefer IS_ENABLED(<FOO>) to ${CONFIG_}<FOO> || ${CONFIG_}<FOO>_MODULE\n" . $herecurr) &&
+			    $fix) {
+				$fixed[$fixlinenr] = "\+#if IS_ENABLED($config)";
 			}
-			if (!$has_break && $has_statement) {
-				WARN("MISSING_BREAK",
-				     "Possible switch case/default not preceded by break or fallthrough comment\n" . $herecurr);
+		}
+
+# check for /* fallthrough */ like comment, prefer fallthrough;
+		my @fallthroughs = (
+			'fallthrough',
+			'@fallthrough@',
+			'lint -fallthrough[ \t]*',
+			'intentional(?:ly)?[ \t]*fall(?:(?:s | |-)[Tt]|t)hr(?:ough|u|ew)',
+			'(?:else,?\s*)?FALL(?:S | |-)?THR(?:OUGH|U|EW)[ \t.!]*(?:-[^\n\r]*)?',
+			'Fall(?:(?:s | |-)[Tt]|t)hr(?:ough|u|ew)[ \t.!]*(?:-[^\n\r]*)?',
+			'fall(?:s | |-)?thr(?:ough|u|ew)[ \t.!]*(?:-[^\n\r]*)?',
+		    );
+		if ($raw_comment ne '') {
+			foreach my $ft (@fallthroughs) {
+				if ($raw_comment =~ /$ft/) {
+					my $msg_level = \&WARN;
+					$msg_level = \&CHK if ($file);
+					&{$msg_level}("PREFER_FALLTHROUGH",
+						      "Prefer 'fallthrough;' over fallthrough comment\n" . $herecurr);
+					last;
+				}
 			}
 		}