[PATCH] checkpatch: Add --strict check for ifs with unnecessary parentheses

[Joe Perches]

An if statement test like
if ((foo == bar) && (baz != qux))
can arguably be better written without the parentheses as
if (foo == bar && baz != qux)

Add a test to find these cases.

Signed-off-by: Joe Perches 
---

David Miller recently commented on the use of unnecessary parentheses
around simple checks like the above.

Perhaps this is an overly subjective/strict interpretation for code
that is not especially better written one way or another.

Anyway, here is an addition for a --strict test that might allow some
fewer resubmissions to satisfy that particular desired style.

 scripts/checkpatch.pl | 24 
 1 file changed, 24 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 2287a0bca863..143ab5ca2c41 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -4496,6 +4496,30 @@ sub process {
}
}
 
+# check for unnecessary parentheses around comparisons in if uses
+   if ($^V && $^V ge 5.10.0 && defined($stat) &&
+   $stat =~ /(^.\s*if\s*($balanced_parens))/) {
+   my $if_stat = $1;
+   my $test = substr($2, 1, -1);
+   my $herectx;
+   while ($test =~ 
/(?:^|[^\w\&\!\~])+\s*\(\s*([\&\!\~]?\s*$Lval\s*(?:$Compare\s*$FuncArg)?)\s*\)/g)
 {
+   my $match = $1;
+   # avoid parentheses around potential macro args
+   next if ($match =~ /^\s*\w+\s*$/);
+   if (!defined($herectx)) {
+   $herectx = $here . "\n";
+   my $cnt = statement_rawlines($if_stat);
+   for (my $n = 0; $n < $cnt; $n++) {
+   my $rl = raw_line($linenr, $n);
+   $herectx .=  $rl . "\n";
+   last if $rl =~ /^[ \+].*\{/;
+   }
+   }
+   CHK("UNNECESSARY_PARENTHESES",
+   "Unnecessary parentheses around '$match'\n" 
. $herectx);
+   }
+   }
+
 #goto labels aren't indented, allow a single space however
if ($line=~/^.\s+[A-Za-z\d_]+:(?![0-9]+)/ and
   !($line=~/^. [A-Za-z\d_]+:/) and !($line=~/^.\s+default:/)) {
-- 
2.10.0.rc2.1.g053435c

[PATCH] checkpatch: Add --strict check for ifs with unnecessary parentheses

[Joe Perches]

An if statement test like
if ((foo == bar) && (baz != qux))
can arguably be better written without the parentheses as
if (foo == bar && baz != qux)

Add a test to find these cases.

Signed-off-by: Joe Perches 
---

David Miller recently commented on the use of unnecessary parentheses
around simple checks like the above.

Perhaps this is an overly subjective/strict interpretation for code
that is not especially better written one way or another.

Anyway, here is an addition for a --strict test that might allow some
fewer resubmissions to satisfy that particular desired style.

 scripts/checkpatch.pl | 24 
 1 file changed, 24 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 2287a0bca863..143ab5ca2c41 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -4496,6 +4496,30 @@ sub process {
}
}
 
+# check for unnecessary parentheses around comparisons in if uses
+   if ($^V && $^V ge 5.10.0 && defined($stat) &&
+   $stat =~ /(^.\s*if\s*($balanced_parens))/) {
+   my $if_stat = $1;
+   my $test = substr($2, 1, -1);
+   my $herectx;
+   while ($test =~ 
/(?:^|[^\w\&\!\~])+\s*\(\s*([\&\!\~]?\s*$Lval\s*(?:$Compare\s*$FuncArg)?)\s*\)/g)
 {
+   my $match = $1;
+   # avoid parentheses around potential macro args
+   next if ($match =~ /^\s*\w+\s*$/);
+   if (!defined($herectx)) {
+   $herectx = $here . "\n";
+   my $cnt = statement_rawlines($if_stat);
+   for (my $n = 0; $n < $cnt; $n++) {
+   my $rl = raw_line($linenr, $n);
+   $herectx .=  $rl . "\n";
+   last if $rl =~ /^[ \+].*\{/;
+   }
+   }
+   CHK("UNNECESSARY_PARENTHESES",
+   "Unnecessary parentheses around '$match'\n" 
. $herectx);
+   }
+   }
+
 #goto labels aren't indented, allow a single space however
if ($line=~/^.\s+[A-Za-z\d_]+:(?![0-9]+)/ and
   !($line=~/^. [A-Za-z\d_]+:/) and !($line=~/^.\s+default:/)) {
-- 
2.10.0.rc2.1.g053435c