[Qemu-devel] [PATCH v4 03/10] checkpatch.pl: check .cpp files

[Tomoki Sekiyama <tomoki.sekiyama@hds.com>]

Enable checkpatch.pl to apply the same checks as C source files for
C++ files with .cpp extensions. It also adds some exceptions for C++
sources to suppress errors for:
  - <> used in C++ template arguments (e.g. template <class T>)
  - :: used to represent namespaces   (e.g. SomeClass::method())
  - : used in class declaration       (e.g. class T : public Super)
  - ~ used in destructor method name  (e.g. T::~T())

Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com>
---
 scripts/checkpatch.pl |   34 ++++++++++++++++++++++++++--------
 1 file changed, 26 insertions(+), 8 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index ec0aa4c..53a12a8 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -1363,7 +1363,7 @@ sub process {
 # Check for incorrect file permissions
 		if ($line =~ /^new (file )?mode.*[7531]\d{0,2}$/) {
 			my $permhere = $here . "FILE: $realfile\n";
-			if ($realfile =~ /(Makefile|Kconfig|\.c|\.h|\.S|\.tmpl)$/) {
+			if ($realfile =~ /(Makefile|Kconfig|\.c|\.cpp|\.h|\.S|\.tmpl)$/) {
 				ERROR("do not set execute permissions for source files\n" . $permhere);
 			}
 		}
@@ -1460,7 +1460,7 @@ sub process {
 		}
 
 # check we are in a valid source file if not then ignore this hunk
-		next if ($realfile !~ /\.(h|c|s|S|pl|sh)$/);
+		next if ($realfile !~ /\.(h|c|cpp|s|S|pl|sh)$/);
 
 #80 column limit
 		if ($line =~ /^\+/ && $prevrawline !~ /\/\*\*/ &&
@@ -1495,7 +1495,7 @@ sub process {
 		}
 
 # check we are in a valid source file C or perl if not then ignore this hunk
-		next if ($realfile !~ /\.(h|c|pl)$/);
+		next if ($realfile !~ /\.(h|c|cpp|pl)$/);
 
 # in QEMU, no tabs are allowed
 		if ($rawline =~ /^\+.*\t/) {
@@ -1505,7 +1505,7 @@ sub process {
 		}
 
 # check we are in a valid C source file if not then ignore this hunk
-		next if ($realfile !~ /\.(h|c)$/);
+		next if ($realfile !~ /\.(h|c|cpp)$/);
 
 # check for RCS/CVS revision markers
 		if ($rawline =~ /^\+.*\$(Revision|Log|Id)(?:\$|)/) {
@@ -1992,7 +1992,7 @@ sub process {
 				\+=|-=|\*=|\/=|%=|\^=|\|=|&=|
 				=>|->|<<|>>|<|>|=|!|~|
 				&&|\|\||,|\^|\+\+|--|&|\||\+|-|\*|\/|%|
-				\?|:
+				\?|::|:
 			}x;
 			my @elements = split(/($ops|;)/, $opline);
 			my $off = 0;
@@ -2066,7 +2066,8 @@ sub process {
 				#   ->
 				#   :   when part of a bitfield
 				} elsif ($op eq '->' || $opv eq ':B') {
-					if ($ctx =~ /Wx.|.xW/) {
+					if ($ctx =~ /Wx.|.xW/ &&
+						!($opv eq ':B' && $line =~ /class/)) {
 						ERROR("spaces prohibited around that '$op' $at\n" . $hereptr);
 					}
 
@@ -2088,7 +2089,11 @@ sub process {
 				} elsif ($op eq '!' || $op eq '~' ||
 					 $opv eq '*U' || $opv eq '-U' ||
 					 $opv eq '&U' || $opv eq '&&U') {
-					if ($ctx !~ /[WEBC]x./ && $ca !~ /(?:\)|!|~|\*|-|\&|\||\+\+|\-\-|\{)$/) {
+					if ($op eq '~' && $ca =~ /::$/ && $realfile =~ /(\.cpp|\.h)$/) {
+						# '~' used as a name of Destructor
+
+					}
+					elsif ($ctx !~ /[WEBC]x./ && $ca !~ /(?:\)|!|~|\*|-|\&|\||\+\+|\-\-|\{)$/) {
 						ERROR("space required before that '$op' $at\n" . $hereptr);
 					}
 					if ($op eq '*' && $cc =~/\s*$Modifier\b/) {
@@ -2126,8 +2131,9 @@ sub process {
 
 				# A colon needs no spaces before when it is
 				# terminating a case value or a label.
+				# Ignored if it is used in class declaration in C++.
 				} elsif ($opv eq ':C' || $opv eq ':L') {
-					if ($ctx =~ /Wx./) {
+					if ($ctx =~ /Wx./ && $line !~ /class/) {
 						ERROR("space prohibited before that '$op' $at\n" . $hereptr);
 					}
 
@@ -2135,6 +2141,18 @@ sub process {
 				} elsif ($ctx !~ /[EWC]x[CWE]/) {
 					my $ok = 0;
 
+					if ($realfile =~ /\.cpp|\.h$/) {
+						# Ignore template arguments <...> in C++
+						if (($op eq '<' || $op eq '>') && $line =~ /<.*>/) {
+							$ok = 1;
+						}
+
+						# Ignore :: in C++
+						if ($op eq '::') {
+							$ok = 1;
+						}
+					}
+
 					# Ignore email addresses <foo@bar>
 					if (($op eq '<' &&
 					     $cc =~ /^\S+\@\S+>/) ||