[PATCH] checkpatch: Avoid "spaces required around that ':'" false positive

[Joe Perches <joe@perches.com>]

Since commit 1f65f947a6a8 ("checkpatch: add checks for
question mark and colon spacing") back in 2008, checkpatch
has reported false positive for asm volatile uses of "::"
checkpatch thinks colons should always have spaces around it.

Add an exception for colons with colons on either side for
this valid asm volatile (and c++) use.

Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Yehuda Yitschak <yehuday@marvell.com>
---
On Tue, 2015-04-14 at 08:46 +0000, Yehuda Yitschak wrote:
> i believe i found a false positive in checkpatch script
> When embedding ARM assembly code in C files checkpatch shouts about spaces after semicolon but that's the syntax of inline assembly.
> ERROR: spaces required around that ':' (ctx:WxO)
> #43: FILE: arch/arm64/kernel/perf_event.c:1221:
> +       asm volatile("msr pmuserenr_el0, %0" :: "r" (0xf));

 scripts/checkpatch.pl | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 78a951f..bf1cc43 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3837,6 +3837,14 @@ sub process {
 					    	$ok = 1;
 					}
 
+					# for asm volatile statements
+					# ignore a colon with another
+					# colon immediately before or after
+					if (($op eq ':') &&
+					    ($ca =~ /:$/ || $cc =~ /^:/)) {
+						$ok = 1;
+					}
+
 					# messages are ERROR, but ?: are CHK
 					if ($ok == 0) {
 						my $msg_type = \&ERROR;