[PATCH] checkpatch: Warn on break after goto or return with same tab indentation

[Joe Perches <joe@perches.com>]

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>
---
> AFAIK there's still no automatic detection of those cases.

There can be now...

 scripts/checkpatch.pl | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 496f9ab..fc22f22 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2439,6 +2439,16 @@ 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",