checkpatch: warn on break after goto or return with same tab indentation

Using break; after a goto or return is unnecessary so emit a warning
when the break is at the same indent level.

So this emits a warning on:

	switch (foo) {
	case 1:
		goto err;
		break;
	}

but not on:

	switch (foo) {
	case 1:
		if (bar())
			goto err;
		break;
	}

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 0cf8b98d8dc9..fc72d64cd2d4 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2450,6 +2450,16 @@ sub process {
                         }
                 }
 
+# check indentation of a line with a break;
+# if the previous line is a goto or return and is indented the same # of tabs
+                if ($sline =~ /^\+([\t]+)break\s*;\s*$/) {
+                        my $tabs = $1;
+                        if ($prevline =~ /^\+$tabs(?:goto|return)\b/) {
+                                WARN("UNNECESSARY_BREAK",
+                                     "break is not useful after a goto or return\n" . $hereprev);
+                        }
+                }
+
 # discourage the addition of CONFIG_EXPERIMENTAL in #if(def).
                 if ($line =~ /^\+\s*\#\s*if.*\bCONFIG_EXPERIMENTAL\b/) {
                         WARN("CONFIG_EXPERIMENTAL",