checkpatch: condition/loop indent checks

Check to see if the block/statement which a condition or loop introduces
is indented correctly.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 55 insertions, 4 deletions

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 8616baee0aeb..13d7a330b5dd 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -1167,10 +1167,10 @@ sub process {
                 }
 
 # Check for potential 'bare' types
-                my ($stat, $cond);
+                my ($stat, $cond, $line_nr_next, $remain_next);
                 if ($realcnt && $line =~ /.\s*\S/) {
-                        ($stat, $cond) = ctx_statement_block($linenr,
-                                                                $realcnt, 0);
+                        ($stat, $cond, $line_nr_next, $remain_next) =
+                                ctx_statement_block($linenr, $realcnt, 0);
                         $stat =~ s/\n./\n /g;
                         $cond =~ s/\n./\n /g;
 
@@ -1712,7 +1712,8 @@ sub process {
                         ERROR("space required before the open parenthesis '('\n" . $herecurr);
                 }
 
-# Check for illegal assignment in if conditional.
+# Check for illegal assignment in if conditional -- and check for trailing
+# statements after the conditional.
                 if ($line =~ /\b(?:if|while|for)\s*\(/ && $line !~ /^.\s*#/) {
                         my ($s, $c) = ($stat, $cond);
 
@@ -1732,6 +1733,56 @@ sub process {
                         }
                 }
 
+# Check relative indent for conditionals and blocks.
+                if ($line =~ /\b(?:(?:if|while|for)\s*\(|do\b)/ && $line !~ /^.\s*#/ && $line !~ /\}\s*while\s*/) {
+                        my ($s, $c) = ($stat, $cond);
+
+                        substr($s, 0, length($c), '');
+
+                        # Make sure we remove the line prefixes as we have
+                        # none on the first line, and are going to readd them
+                        # where necessary.
+                        $s =~ s/\n./\n/gs;
+
+                        # We want to check the first line inside the block
+                        # starting at the end of the conditional, so remove:
+                        #  1) any blank line termination
+                        #  2) any opening brace { on end of the line
+                        #  3) any do (...) {
+                        my $continuation = 0;
+                        my $check = 0;
+                        $s =~ s/^.*\bdo\b//;
+                        $s =~ s/^\s*{//;
+                        if ($s =~ s/^\s*\\//) {
+                                $continuation = 1;
+                        }
+                        if ($s =~ s/^\s*\n//) {
+                                $check = 1;
+                        }
+
+                        # Also ignore a loop construct at the end of a
+                        # preprocessor statement.
+                        if (($prevline =~ /^.\s*#\s*define\s/ ||
+                            $prevline =~ /\\\s*$/) && $continuation == 0) {
+                                $check = 0;
+                        }
+
+                        # Ignore the current line if its is a preprocessor
+                        # line.
+                        if ($s =~ /^\s*#\s*/) {
+                                $check = 0;
+                        }
+
+                        my (undef, $sindent) = line_stats("+" . $s);
+
+                        ##print "line<$line> prevline<$prevline> indent<$indent> sindent<$sindent> check<$check> continuation<$continuation> s<$s>\n";
+
+                        if ($check && (($sindent % 8) != 0 ||
+                            ($sindent <= $indent && $s ne ''))) {
+                                WARN("suspect code indent for conditional statements\n" . $herecurr);
+                        }
+                }
+
 # Check for bitwise tests written as boolean
                 if ($line =~ /
                         (?: