On Wed, Jan 9, 2019 at 9:42 PM Nathan Chancellor <natechancel...@gmail.com> wrote: > > 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 <ndesaulni...@google.com>
Thanks for sending the v2. I'll leave review to the maintainers to confirm my suspicions about the code's intent. > Signed-off-by: Nathan Chancellor <natechancel...@gmail.com> > --- > > 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 > -- Thanks, ~Nick Desaulniers
