[PATCH v2] isdn: avm: Fix string plus integer warning from Clang

From: Nathan Chancellor
Date: Thu Jan 10 2019 - 00:42:42 EST


A recent commit in Clang expanded the -Wstring-plus-int warning, showing
some odd behavior in this file.

drivers/isdn/hardware/avm/b1.c:426:30: warning: adding 'int' to a string does not append to the string [-Wstring-plus-int]
cinfo->version[j] = "\0\0" + 1;
~~~~~~~^~~
drivers/isdn/hardware/avm/b1.c:426:30: note: use array indexing to silence this warning
cinfo->version[j] = "\0\0" + 1;
^
& [ ]
1 warning generated.

This is equivalent to just "\0". Nick pointed out that it is smarter to
use "" instead of "\0" because "" is used elsewhere in the kernel and
can be deduplicated at the linking stage.

Link: https://github.com/ClangBuiltLinux/linux/issues/309
Suggested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
---

v1 -> v2:

* Use "" instead of "\0", as they are equivalent, but "" can be
deduplicated by the linker, as pointed out by Nick.

drivers/isdn/hardware/avm/b1.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/isdn/hardware/avm/b1.c b/drivers/isdn/hardware/avm/b1.c
index 4ac378e48902..40ca1e8fa09f 100644
--- a/drivers/isdn/hardware/avm/b1.c
+++ b/drivers/isdn/hardware/avm/b1.c
@@ -423,7 +423,7 @@ void b1_parse_version(avmctrl_info *cinfo)
int i, j;

for (j = 0; j < AVM_MAXVERSION; j++)
- cinfo->version[j] = "\0\0" + 1;
+ cinfo->version[j] = "";
for (i = 0, j = 0;
j < AVM_MAXVERSION && i < cinfo->versionlen;
j++, i += cinfo->versionbuf[i] + 1)
--
2.20.1