Re: [PATCH] tracetool: work around ust <sys/sdt.h> include conflict

[Stefan Hajnoczi]

On Thu, Jun 25, 2020 at 03:07:57PM +0100, Stefan Hajnoczi wrote:
> Both the dtrace and ust backends may include <sys/sdt.h> but LTTng
> Userspace Tracer 2.11 and later requires SDT_USE_VARIADIC to be defined
> before including the header file.
> 
> This is a classic problem with C header files included from different
> parts of a program. If the same header is included twice within the same
> compilation unit then the first inclusion determines the macro
> environment.
> 
> Work around this by defining SDT_USE_VARIADIC in the dtrace backend too.
> It doesn't hurt and fixes a missing STAP_PROBEV() compiler error when
> the ust backend is enabled together with the dtrace backend.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
> I am also sending a fix to the LTTng Userspace Tracer project to add
> -DSDT_USE_VARIADIC to the pkg-config CFLAGS so that applications define
> the macro consistently. But this patch is still needed as a workaround
> for lttng-ust 2.11.
> ---
>  scripts/tracetool/backend/dtrace.py | 6 ++++++
>  1 file changed, 6 insertions(+)

Thanks, applied to my tracing tree:
https://github.com/stefanha/qemu/commits/tracing

Stefan

signature.asc
Description: PGP signature