[PATCH] checkpatch: Improve the unnecessary initialisers tests

[Joe Perches <joe@perches.com>]

Global and static variables don't need to be initialized to 0.

There is already a test for this but the output message doesn't
mention booleans initialized to false.

Improve the output message and the test by adding various forms
with possible specific integer types and possible multiple zeros.

Miscellanea:

o Use a variable to hold the possible 0 test

Signed-off-by: Shailendra Verma <shailendra.v@samsung.com>
Signed-off-by: Joe Perches <joe@perches.com>
---
 scripts/checkpatch.pl | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 2d88cbf9..2b3c228 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -370,6 +370,8 @@ our $typeTypedefs = qr{(?x:
 	$typeKernelTypedefs\b
 )};
 
+our $zero_initializer = qr{(?:(?:0[xX])?0+$Int_type?|NULL|false)\b};
+
 our $logFunctions = qr{(?x:
 	printk(?:_ratelimited|_once|)|
 	(?:[a-z0-9]+_){1,2}(?:printk|emerg|alert|crit|err|warning|warn|notice|info|debug|dbg|vdbg|devel|cont|WARN)(?:_ratelimited|_once|)|
@@ -3334,21 +3336,20 @@ sub process {
 		}
 
 # check for global initialisers.
-		if ($line =~ /^\+$Type\s*$Ident(?:\s+$Modifier)*\s*=\s*(?:0|NULL|false)\s*;/) {
+		if ($line =~ /^\+$Type\s*$Ident(?:\s+$Modifier)*\s*=\s*($zero_initializer)\s*;/) {
 			if (ERROR("GLOBAL_INITIALISERS",
-				  "do not initialise globals to 0 or NULL\n" .
-				      $herecurr) &&
+				  "do not initialise globals to $1\n" . $herecurr) &&
 			    $fix) {
-				$fixed[$fixlinenr] =~ s/(^.$Type\s*$Ident(?:\s+$Modifier)*)\s*=\s*(0|NULL|false)\s*;/$1;/;
+				$fixed[$fixlinenr] =~ s/(^.$Type\s*$Ident(?:\s+$Modifier)*)\s*=\s*$zero_initializer\s*;/$1;/;
 			}
 		}
 # check for static initialisers.
-		if ($line =~ /^\+.*\bstatic\s.*=\s*(0|NULL|false)\s*;/) {
+		if ($line =~ /^\+.*\bstatic\s.*=\s*($zero_initializer)\s*;/) {
 			if (ERROR("INITIALISED_STATIC",
-				  "do not initialise statics to 0 or NULL\n" .
+				  "do not initialise statics to $1\n" .
 				      $herecurr) &&
 			    $fix) {
-				$fixed[$fixlinenr] =~ s/(\bstatic\s.*?)\s*=\s*(0|NULL|false)\s*;/$1;/;
+				$fixed[$fixlinenr] =~ s/(\bstatic\s.*?)\s*=\s*$zero_initializer\s*;/$1;/;
 			}
 		}