Re: [PATCH v3 bpf-next 01/14] samples: bpf: makefile: fix HDR_PROBE "echo"

[Ivan Khoronzhuk]

On Mon, Sep 16, 2019 at 01:13:23PM -0700, Andrii Nakryiko wrote:
> On Mon, Sep 16, 2019 at 3:59 AM Ivan Khoronzhuk
> <ivan.khoronzhuk@xxxxxxxxxx> wrote:
> > echo should be replaced with echo -e to handle '\n' correctly, but
> > instead, replace it with printf as some systems can't handle echo -e.
> >
> > Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx>
> > ---
> >  samples/bpf/Makefile | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
> > index 1d9be26b4edd..f50ca852c2a8 100644
> > --- a/samples/bpf/Makefile
> > +++ b/samples/bpf/Makefile
> > @@ -201,7 +201,7 @@ endif
> >
> >  # Don't evaluate probes and warnings if we need to run make recursively
> >  ifneq ($(src),)
> > -HDR_PROBE := $(shell echo "\#include <linux/types.h>\n struct list_head { int a; }; int main() { return 0; }" | \
> > +HDR_PROBE := $(shell printf "\#include <linux/types.h>\n struct list_head { int a; }; int main() { return 0; }" | \
>
> printf change is fine, but I'm confused about \# at the beginning of
> the string. Not sure what was the intent, but it seems like it should
> work with just #include at the beginning.

At least no warns, but looks like should work.
Will try it in next v.

> >         $(HOSTCC) $(KBUILD_HOSTCFLAGS) -x c - -o /dev/null 2>/dev/null && \
> >         echo okay)
> >
> > --
> > 2.17.1

--
Regards,
Ivan Khoronzhuk