perf python: Remove dependency on 'machine' methods

The python binding still doesn't provide symbol resolving facilities,
but the recent addition of the trace_event__register_resolver() function
made it add as a dependency the machine__resolve_kernel_addr() method,
that in turn drags all the symbol resolving code.

The problem:

  [root@zoo ~]# perf test -v python
  17: Try 'import perf' in python, checking link problems      :
  --- start ---
  test child forked, pid 6853
  Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
  ImportError: /tmp/build/perf/python/perf.so: undefined symbol: machine__resolve_kernel_addr
  test child finished with -1
  ---- end ----
  Try 'import perf' in python, checking link problems: FAILED!
  [root@zoo ~]#

Fix it by requiring this function to receive the resolver as a
parameter, just like pevent_register_function_resolver(), i.e. do
not explicitely refer to an object file not included in
tools/perf/util/python-ext-sources.

  [root@zoo ~]# perf test python
  17: Try 'import perf' in python, checking link problems      : Ok
  [root@zoo ~]#

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Fixes: c3168b0d ("perf symbols: Provide libtraceevent callback to resolve kernel symbols")
Link: http://lkml.kernel.org/n/tip-vxlhh95v2em9zdbgj3jm7xi5@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-trace.c

@@ -1489,7 +1489,7 @@ static int trace__symbols_init(struct trace *trace, struct perf_evlist *evlist)
 	if (trace->host == NULL)
 		return -ENOMEM;
 
-	if (trace_event__register_resolver(trace->host) < 0)
+	if (trace_event__register_resolver(trace->host, machine__resolve_kernel_addr) < 0)
 		return -errno;
 
 	err = __machine__synthesize_threads(trace->host, &trace->tool, &trace->opts.target,

tools/perf/util/trace-event.c

@@ -50,14 +50,13 @@ static int trace_event__init2(void)
 	return 0;
 }
 
-int trace_event__register_resolver(struct machine *machine)
+int trace_event__register_resolver(struct machine *machine,
+				   pevent_func_resolver_t *func)
 {
 	if (!tevent_initialized && trace_event__init2())
 		return -1;
 
-	return pevent_set_function_resolver(tevent.pevent,
-					    machine__resolve_kernel_addr,
-					    machine);
+	return pevent_set_function_resolver(tevent.pevent, func, machine);
 }
 
 void trace_event__cleanup(struct trace_event *t)

tools/perf/util/trace-event.h

@@ -18,7 +18,8 @@ struct trace_event {
 
 int trace_event__init(struct trace_event *t);
 void trace_event__cleanup(struct trace_event *t);
-int trace_event__register_resolver(struct machine *machine);
+int trace_event__register_resolver(struct machine *machine,
+				   pevent_func_resolver_t *func);
 struct event_format*
 trace_event__tp_format(const char *sys, const char *name);