checkpatch: warn on unnecessary else after return or break
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@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index ac1d6b0..d833b73 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2342,6 +2342,16 @@
# 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",
