perf/tool: Make the event parser re-entrant

Make the event parser reentrant by creating separate
scanner for each parsing. The scanner is passed to the bison
as and argument to the lexer.

Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
[ Cleaned up the patch. ]
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1339741902-8449-11-git-send-email-zheng.z.yan@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

tools/perf/util/parse-events.y

@@ -1,6 +1,8 @@
-
+%pure-parser
 %name-prefix "parse_events_"
 %parse-param {void *_data}
+%parse-param {void *scanner}
+%lex-param {void* scanner}
 
 %{
 
@@ -11,8 +13,9 @@
 #include "types.h"
 #include "util.h"
 #include "parse-events.h"
+#include "parse-events-bison.h"
 
-extern int parse_events_lex (void);
+extern int parse_events_lex (YYSTYPE* lvalp, void* scanner);
 
 #define ABORT_ON(val) \
 do { \
@@ -286,7 +289,7 @@ sep_slash_dc: '/' | ':' |
 
 %%
 
-void parse_events_error(void *data __used,
+void parse_events_error(void *data __used, void *scanner __used,
 			char const *msg __used)
 {
 }