perf probe: Show accessible global variables

Add --externs for allowing --vars to show accessible global (externally
defined) variables from a given probe point too.

This will give you a hint which globals can be accessible from the probe point.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101021101335.3542.31003.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
index baffd25..516912a 100644
--- a/tools/perf/util/probe-finder.h
+++ b/tools/perf/util/probe-finder.h
@@ -30,7 +30,8 @@
 
 /* Find available variables */
 extern int find_available_vars_at(int fd, struct perf_probe_event *pev,
-				  struct variable_list **vls, int max_points);
+				  struct variable_list **vls, int max_points,
+				  bool externs);
 
 #include <dwarf.h>
 #include <libdw.h>
@@ -70,6 +71,8 @@
 	struct variable_list	*vls;		/* Found variable lists */
 	int			nvls;		/* Number of variable lists */
 	int			max_vls;	/* Max no. of variable lists */
+	bool			externs;	/* Find external vars too */
+	bool			child;		/* Search child scopes */
 };
 
 struct line_finder {