checkpatch: Add --strict test for function pointer calling style

Peter Hurley wrote:

The use of older function ptr calling style, (*fn)(), makes static
analysis more error-prone; replace with modern fn() style.

So make checkpatch emit a --strict test for that condition.

Update the unnecessary parentheses test for dereferencing
objects at the same time and create a $fix mechanism too.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 21 insertions, 3 deletions

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 41e7db451cc0..893cbd517f89 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3844,9 +3844,27 @@ sub process {
 # ie: &(foo->bar) should be &foo->bar and *(foo->bar) should be *foo->bar
 
                 while ($line =~ /(?:[^&]&\s*|\*)\(\s*($Ident\s*(?:$Member\s*)+)\s*\)/g) {
-                        CHK("UNNECESSARY_PARENTHESES",
-                            "Unnecessary parentheses around $1\n" . $herecurr);
-                    }
+                        my $var = $1;
+                        if (CHK("UNNECESSARY_PARENTHESES",
+                                "Unnecessary parentheses around $var\n" . $herecurr) &&
+                            $fix) {
+                                $fixed[$fixlinenr] =~ s/\(\s*\Q$var\E\s*\)/$var/;
+                        }
+                }
+
+# check for unnecessary parentheses around function pointer uses
+# ie: (foo->bar)(); should be foo->bar();
+# but not "if (foo->bar) (" to avoid some false positives
+                if ($line =~ /(\bif\s*|)(\(\s*$Ident\s*(?:$Member\s*)+\))[ \t]*\(/ && $1 !~ /^if/) {
+                        my $var = $2;
+                        if (CHK("UNNECESSARY_PARENTHESES",
+                                "Unnecessary parentheses around function pointer $var\n" . $herecurr) &&
+                            $fix) {
+                                my $var2 = deparenthesize($var);
+                                $var2 =~ s/\s//g;
+                                $fixed[$fixlinenr] =~ s/\Q$var\E/$var2/;
+                        }
+                }
 
 #goto labels aren't indented, allow a single space however
                 if ($line=~/^.\s+[A-Za-z\d_]+:(?![0-9]+)/ and