[Bug other/61257] New: configure should check if sys/sdt.h is usable, not just checking the existance of the header

[doko at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61257

            Bug ID: 61257
           Summary: configure should check if sys/sdt.h is usable, not
                    just checking the existance of the header
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: other
          Assignee: unassigned at gcc dot gnu.org
          Reporter: doko at gcc dot gnu.org

splitting out to a new issue, this started in PR61231, and it came up before in
https://gcc.gnu.org/ml/gcc-patches/2012-12/msg01122.html

(Note that strictly speaking, systemtap per se doesn't need to support
an architecture for the sys/sdt.h header file to work there.  gdb is 
a fully independent client of sys/sdt.h markers.)

Perhaps the way to go forward is to have the gcc configury test-compile
some toy sys/sdt.h code [1], and activate the probes only if that works.

[1]
#include <sys/sdt.h>

int main ()
{
   DTRACE_PROBE(foo,bar);
   return 0;
}