[PATCH] checkpatch: warn on unnecessary else after return or break

From: Joe Perches
Date: Mon Jun 09 2014 - 00:12:18 EST


Using an else following a break or return can unnecessarily
indent code blocks.

ie:
for (i = 0; i < 100; i++) {
int foo = bar();
if (foo < 1)
break;
else
usleep(1);
}

is generally better written as:

for (i = 0; i < 100; i++) {
int foo = bar();
if (foo < 1)
break;
usleep(1);
}

Warn when a bare else statement is preceded by a
break or return indented 1 tab more than the else.

Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
---
scripts/checkpatch.pl | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 010b18e..9059fd0 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2342,6 +2342,16 @@ sub process {
# check we are in a valid C source file if not then ignore this hunk
next if ($realfile !~ /\.(h|c)$/);

+# check indentation of any line with a bare else
+# if the previous line is a break or return and is indented 1 tab more...
+ if ($sline =~ /^\+([\t]+)(?:}[ \t]*)?else(?:[ \t]*{)?\s*$/) {
+ my $tabs = length($1) + 1;
+ if ($prevline =~ /^\+\t{$tabs,$tabs}(?:break|return)\b/) {
+ WARN("UNNECESSARY_ELSE",
+ "else is not generally useful after a break or return\n" . $hereprev);
+ }
+ }
+
# discourage the addition of CONFIG_EXPERIMENTAL in #if(def).
if ($line =~ /^\+\s*\#\s*if.*\bCONFIG_EXPERIMENTAL\b/) {
WARN("CONFIG_EXPERIMENTAL",


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