Re: [RFC 0/4] tools lib traceevent: Install fixes

From: Namhyung Kim
Date: Mon Aug 01 2016 - 23:12:56 EST


On Mon, Aug 01, 2016 at 07:41:28PM +0200, Jiri Olsa wrote:
> hi,
> sending traceevent changes to make this lib installable
> under rpm spec.
>
> Basically adding support to:
> - install header files
> - install version links
>
> Having this patchset applied over the fedora source,
> I could built following rpms:
>
> kernel-tools-libs
> kernel-tools-libs-devel
>
> with added libtraceevent stuff:
>
> $ rpm -ql kernel-tools-libs
> /usr/lib64/libcpupower.so.0
> /usr/lib64/libcpupower.so.0.0.0
> /usr/lib64/libtraceevent.so.1
> /usr/lib64/libtraceevent.so.1.1.0
>
> $ rpm -ql kernel-tools-libs-devel
> /usr/include/cpufreq.h
> /usr/include/traceevent
> /usr/include/traceevent/event-parse.h
> /usr/include/traceevent/event-utils.h
> /usr/include/traceevent/kbuffer.h
> /usr/lib64/libcpupower.so
> /usr/lib64/libtraceevent.a
> /usr/lib64/libtraceevent.so
>
> and could build following ex.c outside the kernel tree:
>
> $ cat ex.c
> #include <traceevent/event-parse.h>
>
> int main(void)
> {
> struct pevent *pevent = pevent_alloc();
> printf("krava %p\n", pevent);
> return 0;
> }
> $ gcc -o ex ex.c -ltraceevent -ldl
> $ ./ex
> krava 0x10c6010
> $

On my system, building ex.c with libtraceevent failed:

$ gcc -I ~/.local/include/ ex.c -L ~/.local/lib64 -ltraceevent -ldl
/home/namhyung/.local/lib64/libtraceevent.so: undefined reference to `str_error_r'
collect2: error: ld returned 1 exit status


Also I think it'd be better for libtraceevent has dependency to libdl
explicitly so that we can get rid of -ldl at the end.