Re: scripts/checkpatch: Concatenated strings should use spaces between elements

[Joe Perches <joe@perches.com>]

On Wed, 2017-10-18 at 00:58 +0200, Heinrich Schuchardt wrote:
> On 10/18/2017 12:43 AM, Joe Perches wrote:
> > On Tue, 2017-10-17 at 23:17 +0200, Heinrich Schuchardt wrote:
> > > This patch creates a warning (CHECK)
> > > "Concatenated strings should use spaces between elements"
[]
> > > +void foo(void)
> > > +{
> > > +	test(L"\"");
> > 
> > In this case, L must be a constant string and you
> > are concatenating L and "\""
> > 
> > 
> 
> See ISO/IEC 9899:1999
> 
> 6.4.5 String literals
> 
> <cite>
> A character string literal is a sequence of zero or more multibyte
> characters enclosed in double-quotes, as in "xyz"
> A wide  string  literal is  the  same, except prefixed by the
> letter L.
> </cite>
> 
> L"foo" is a literal of type wchar_t * and not two strings.
> L is a qualifier and not a constant string.
> 
> Just like ULL in 10ULL.

How about trying this:

>From 99bd0ab78a810f537e18a24be42379a6af9d5045 Mon Sep 17 00:00:00 2001
Message-Id: <99bd0ab78a810f537e18a24be42379a6af9d5045.1508286849.git.joe@perches.com>
From: Joe Perches <joe@perches.com>
Date: Tue, 17 Oct 2017 17:11:14 -0700
Subject: [PATCH] checkpatch: Support wide strings

Allow prefixing typical strings with L for wide strings

Signed-off-by: Joe Perches <joe@perches.com>
---
 scripts/checkpatch.pl | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 359c02b0954e..9f04f803e96b 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -393,7 +393,7 @@ our $Binary	= qr{(?i)0b[01]+$Int_type?};
 our $Hex	= qr{(?i)0x[0-9a-f]+$Int_type?};
 our $Int	= qr{[0-9]+$Int_type?};
 our $Octal	= qr{0[0-7]+$Int_type?};
-our $String	= qr{"[X\t]*"};
+our $String	= qr{(?:\bL)?"[X\t]*"};
 our $Float_hex	= qr{(?i)0x[0-9a-f]+p-?[0-9]+[fl]?};
 our $Float_dec	= qr{(?i)(?:[0-9]+\.[0-9]*|[0-9]*\.[0-9]+)(?:e-?[0-9]+)?[fl]?};
 our $Float_int	= qr{(?i)[0-9]+e-?[0-9]+[fl]?};
@@ -5262,13 +5262,14 @@ sub process {
 		}
 
 # concatenated string without spaces between elements
-		if ($line =~ /$String[A-Z_]/ || $line =~ /[A-Za-z0-9_]$String/) {
+		if ($line =~ /$String[A-Z_]/ ||
+		    ($line =~ /([A-Za-z0-9_]+)$String/ && $1 !~ /^L$/)) {
 			CHK("CONCATENATED_STRING",
 			    "Concatenated strings should use spaces between elements\n" . $herecurr);
 		}
 
 # uncoalesced string fragments
-		if ($line =~ /$String\s*"/) {
+		if ($line =~ /$String\s*L?"/) {
 			WARN("STRING_FRAGMENTS",
 			     "Consecutive strings are generally better as a single string\n" . $herecurr);
 		}
-- 
2.10.0.rc2.1.g053435c