[Qemu-devel] [PULL 01/22] scripts/checkpatch.pl: Enforce multiline comment syntax

[Peter Maydell]

We now require Linux-kernel-style multiline comments:
    /*
     * line one
     * line two
     */

Enforce this in checkpatch.pl, by backporting the relevant
parts of the Linux kernel's checkpatch.pl. (The only changes
needed are that Linux's checkpatch.pl WARN() function takes
an extra argument that ours does not, and the kernel has a
special case for networking code we don't want.)"

The kernel's checkpatch does not enforce "leading /* on
a line of its own, so that part is unique to QEMU's checkpatch.

Sample warning output:

WARNING: Block comments use a leading /* on a separate line
#34: FILE: hw/intc/arm_gicv3_common.c:39:
+    /* Older versions of QEMU had a bug in the handling of state save/restore

Signed-off-by: Peter Maydell <address@hidden>
Acked-by: Thomas Huth <address@hidden>
Reviewed-by: Markus Armbruster <address@hidden>
---
 scripts/checkpatch.pl | 48 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index a892a6cc7c3..18e16b79dfc 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -1569,6 +1569,54 @@ sub process {
 # check we are in a valid C source file if not then ignore this hunk
                next if ($realfile !~ /\.(h|c|cpp)$/);
 
+# Block comment styles
+
+               # Block comments use /* on a line of its own
+               if ($rawline !~ address@hidden/\*.*\*/[ \t]*$@ &&       #inline 
/*...*/
+                   $rawline =~ address@hidden/\*\*?[ \t]*.+[ \t]*$@) { # /* or 
/** non-blank
+                       WARN("Block comments use a leading /* on a separate 
line\n" . $herecurr);
+               }
+
+# Block comments use * on subsequent lines
+               if ($prevline =~ /$;[ \t]*$/ &&                 #ends in comment
+                   $prevrawline =~ /^\+.*?\/\*/ &&             #starting /*
+                   $prevrawline !~ /\*\/[ \t]*$/ &&            #no trailing */
+                   $rawline =~ /^\+/ &&                        #line is new
+                   $rawline !~ /^\+[ \t]*\*/) {                #no leading *
+                       WARN("Block comments use * on subsequent lines\n" . 
$hereprev);
+               }
+
+# Block comments use */ on trailing lines
+               if ($rawline !~ address@hidden \t]*\*/[ \t]*$@ &&       
#trailing */
+                   $rawline !~ address@hidden/\*.*\*/[ \t]*$@ &&       #inline 
/*...*/
+                   $rawline !~ address@hidden,}/[ \t]*$@ &&    #trailing **/
+                   $rawline =~ address@hidden \t]*.+\*\/[ \t]*$@) {    #non 
blank */
+                       WARN("Block comments use a trailing */ on a separate 
line\n" . $herecurr);
+               }
+
+# Block comment * alignment
+               if ($prevline =~ /$;[ \t]*$/ &&                 #ends in comment
+                   $line =~ /^\+[ \t]*$;/ &&                   #leading comment
+                   $rawline =~ /^\+[ \t]*\*/ &&                #leading *
+                   (($prevrawline =~ /^\+.*?\/\*/ &&           #leading /*
+                     $prevrawline !~ /\*\/[ \t]*$/) ||         #no trailing */
+                    $prevrawline =~ /^\+[ \t]*\*/)) {          #leading *
+                       my $oldindent;
+                       $prevrawline =~ address@hidden([ \t]*/?)\*@;
+                       if (defined($1)) {
+                               $oldindent = expand_tabs($1);
+                       } else {
+                               $prevrawline =~ address@hidden(.*/?)\*@;
+                               $oldindent = expand_tabs($1);
+                       }
+                       $rawline =~ address@hidden([ \t]*)\*@;
+                       my $newindent = $1;
+                       $newindent = expand_tabs($newindent);
+                       if (length($oldindent) ne length($newindent)) {
+                               WARN("Block comments should align the * on each 
line\n" . $hereprev);
+                       }
+               }
+
 # Check for potential 'bare' types
                my ($stat, $cond, $line_nr_next, $remain_next, $off_next,
                    $realline_next);
-- 
2.19.2