[RFC PATCH] checkpatch: Add warning for asymmetric brace use

From: Joe Perches
Date: Wed Jan 11 2012 - 14:58:20 EST


On Tue, 2012-01-10 at 09:30 -0800, Joe Perches wrote:
> Here's a snippet where checkpatch does not emit
> a warning where it reasonably could:
>
> int main(int argc, char **argv)
> {
> int a;
> if (a) {
> int foo;
> int bar;
> } else
> int foo;
> }
>
> Maybe you could look at it?

Hey Andy.
Here's a possible checkpatch patch.
It seems to work on the test cases I've tried.
---
scripts/checkpatch.pl | 28 ++++++++++++++++++++--------
1 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index e3bfcbe..19f228c 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2882,7 +2882,8 @@ sub process {
#print "chunks<$#chunks> linenr<$linenr> endln<$endln> level<$level>\n";
#print "APW: <<$chunks[1][0]>><<$chunks[1][1]>>\n";
if ($#chunks > 0 && $level == 0) {
- my $allowed = 0;
+ my @allowed = ();
+ my $allow = 0;
my $seen = 0;
my $herectx = $here . "\n";
my $ln = $linenr - 1;
@@ -2893,6 +2894,7 @@ sub process {
my ($whitespace) = ($cond =~ /^((?:\s*\n[+-])*\s*)/s);
my $offset = statement_rawlines($whitespace) - 1;

+ $allowed[$allow] = 0;
#print "COND<$cond> whitespace<$whitespace> offset<$offset>\n";

# We have looked at and allowed this specific line.
@@ -2905,23 +2907,33 @@ sub process {

$seen++ if ($block =~ /^\s*{/);

- #print "cond<$cond> block<$block> allowed<$allowed>\n";
+ #print "cond<$cond> block<$block> allowed<$allowed[$allow]>\n";
if (statement_lines($cond) > 1) {
#print "APW: ALLOWED: cond<$cond>\n";
- $allowed = 1;
+ $allowed[$allow] = 1;
}
if ($block =~/\b(?:if|for|while)\b/) {
#print "APW: ALLOWED: block<$block>\n";
- $allowed = 1;
+ $allowed[$allow] = 1;
}
if (statement_block_size($block) > 1) {
#print "APW: ALLOWED: lines block<$block>\n";
- $allowed = 1;
+ $allowed[$allow] = 1;
}
+ $allow++;
}
- if ($seen && !$allowed) {
- WARN("BRACES",
- "braces {} are not necessary for any arm of this statement\n" . $herectx);
+ if ($seen) {
+ my $sum_allowed = 0;
+ foreach (@allowed) {
+ $sum_allowed += $_;
+ }
+ if ($sum_allowed == 0) {
+ WARN("BRACES",
+ "braces {} are not necessary for any arm of this statement\n" . $herectx);
+ } elsif ($sum_allowed != $allow) {
+ WARN("BRACES",
+ "braces {} should be used on all arms of this statement\n" . $herectx);
+ }
}
}
}


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