lint: checkpatch: Add SUSPICIOUS_CODE_INDENT test

This patch adds a new test to checkpatch that identifies cases where a
line after a conditional statement is incorrectly intended (possibly
indicating the mistake of forgetting to add braces), like this:

 if (a)
   b;
   c;

Unfortunately, it seems like checkpatch is partially unmaintained in
upstream Linux at the moment with maintainers either not responding at
all or not even willing to look at new patches [1]. Since detecting this
error class is important to coreboot, let's just carry this feature
locally for now.

[1] https://lkml.org/lkml/2021/4/15/1488

Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: I7bb90b56dfc7582271d2b82cb42a2c1df477054f
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51838
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>
This commit is contained in:
Julius Werner 2021-03-25 21:12:49 -07:00
parent aee70a8a8e
commit 218906df66
1 changed files with 56 additions and 10 deletions

View File

@ -1197,8 +1197,12 @@ sub copy_spacing {
sub line_stats { sub line_stats {
my ($line) = @_; my ($line) = @_;
# Drop the diff line leader and expand tabs # Drop the diff line leader
$line =~ s/^.//; $line =~ s/^.//;
# Treat labels like whitespace when counting indentation
$line =~ s/^( ?$Ident:)/" " x length($1)/e;
$line = expand_tabs($line); $line = expand_tabs($line);
# Pick the indent from the front of the line. # Pick the indent from the front of the line.
@ -1331,15 +1335,13 @@ sub ctx_statement_block {
my $type = ''; my $type = '';
my $level = 0; my $level = 0;
my @stack = (); my @stack = (['', $level]);
my $p; my $p;
my $c; my $c;
my $len = 0; my $len = 0;
my $remainder; my $remainder;
while (1) { while (1) {
@stack = (['', 0]) if ($#stack == -1);
#warn "CSB: blk<$blk> remain<$remain>\n"; #warn "CSB: blk<$blk> remain<$remain>\n";
# If we are about to drop off the end, pull in more # If we are about to drop off the end, pull in more
# context. # context.
@ -1373,9 +1375,9 @@ sub ctx_statement_block {
# Handle nested #if/#else. # Handle nested #if/#else.
if ($remainder =~ /^#\s*(?:ifndef|ifdef|if)\s/) { if ($remainder =~ /^#\s*(?:ifndef|ifdef|if)\s/) {
push(@stack, [ $type, $level ]); push(@stack, [ $type, $level ]);
} elsif ($remainder =~ /^#\s*(?:else|elif)\b/) { } elsif ($remainder =~ /^#\s*(?:else|elif)\b/ && $#stack > 0) {
($type, $level) = @{$stack[$#stack - 1]}; ($type, $level) = @{$stack[$#stack]};
} elsif ($remainder =~ /^#\s*endif\b/) { } elsif ($remainder =~ /^#\s*endif\b/ && $#stack > 0) {
($type, $level) = @{pop(@stack)}; ($type, $level) = @{pop(@stack)};
} }
@ -1545,9 +1547,9 @@ sub ctx_block_get {
# Handle nested #if/#else. # Handle nested #if/#else.
if ($lines[$line] =~ /^.\s*#\s*(?:ifndef|ifdef|if)\s/) { if ($lines[$line] =~ /^.\s*#\s*(?:ifndef|ifdef|if)\s/) {
push(@stack, $level); push(@stack, $level);
} elsif ($lines[$line] =~ /^.\s*#\s*(?:else|elif)\b/) { } elsif ($lines[$line] =~ /^.\s*#\s*(?:else|elif)\b/ && $#stack > 0) {
$level = $stack[$#stack - 1]; $level = $stack[$#stack];
} elsif ($lines[$line] =~ /^.\s*#\s*endif\b/) { } elsif ($lines[$line] =~ /^.\s*#\s*endif\b/ && $#stack > 0) {
$level = pop(@stack); $level = pop(@stack);
} }
@ -3615,6 +3617,50 @@ sub process {
WARN("SUSPECT_CODE_INDENT", WARN("SUSPECT_CODE_INDENT",
"suspect code indent for conditional statements ($indent, $sindent)\n" . $herecurr . "$stat_real\n"); "suspect code indent for conditional statements ($indent, $sindent)\n" . $herecurr . "$stat_real\n");
} }
# Also check if the next statement after the previous condition has the same indent
my ($stat_next, undef, $line_nr_next_next) =
ctx_statement_block($line_nr_next, $remain_next, $off_next);
my $s_next = $stat_next;
# Remove line prefixes
$s_next =~ s/\n./\n/g;
# Remove any comments
$s_next =~ s/$;//g;
# Remove any leading labels
$s_next =~ s/\n( ?$Ident:)/"\n" . " " x length($1)/eg;
# Skip this check for in case next statement starts with 'else'
if ($s_next !~ /\belse\b/) {
# Remove while that belongs to a do {} while
if ($stat =~ /\bdo\b/) {
$s_next =~ s/^.*\bwhile\b\s*($balanced_parens)\s*?//;
}
# Remove blank lines
$s_next =~ s/\s*\\?\n//g;
# Get the real next lines
my $next_nof_lines = $line_nr_next_next - $line_nr_next;
my $stat_next_real = raw_line($line_nr_next, $next_nof_lines);
if (!defined($stat_next_real)) {
$stat_next_real = "";
} elsif ($next_nof_lines > 1) {
$stat_next_real = "[...]\n$stat_next_real";
}
my (undef, $nindent) = line_stats('+' . $s_next);
#print "stat_next<$stat_next> stat<$stat> indent<$indent> nindent<$nindent> s_next<$s_next> stat_next_real<$stat_next_real>\n";
if ($nindent > $indent) {
WARN("SUSPICIOUS_CODE_INDENT",
"suspicious code indentation after conditional statements\n" .
$herecurr . "$stat_real\n$stat_next_real\n");
}
}
} }
# Track the 'values' across context and added lines. # Track the 'values' across context and added lines.