perf record: Export the callchain parsing routine and help

Will be used by perf top, that will first setup the symbol system to
deal with callchains and then call these routines to ask the kernel
for callchains.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-jg0dh8rmlx7x11e7u7mnasvd@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-record.c

@@ -868,7 +868,8 @@ static int get_stack_size(char *str, unsigned long *_size)
 }
 #endif /* LIBUNWIND_SUPPORT */
 
-static int parse_callchain_opt(const struct option *opt, const char *arg, int unset)
+int record_parse_callchain_opt(const struct option *opt,
+			       const char *arg, int unset)
 {
 	struct perf_record_opts *opts = opt->value;
 	char *tok, *name, *saveptr = NULL;
@@ -973,9 +974,9 @@ static struct perf_record record = {
 #define CALLCHAIN_HELP "do call-graph (stack chain/backtrace) recording: "
 
 #ifdef LIBUNWIND_SUPPORT
-static const char callchain_help[] = CALLCHAIN_HELP "[fp] dwarf";
+const char record_callchain_help[] = CALLCHAIN_HELP "[fp] dwarf";
 #else
-static const char callchain_help[] = CALLCHAIN_HELP "[fp]";
+const char record_callchain_help[] = CALLCHAIN_HELP "[fp]";
 #endif
 
 /*
@@ -1020,8 +1021,8 @@ const struct option record_options[] = {
 	OPT_BOOLEAN(0, "group", &record.opts.group,
 		    "put the counters into a counter group"),
 	OPT_CALLBACK_DEFAULT('g', "call-graph", &record.opts,
-			     "mode[,dump_size]", callchain_help,
-			     &parse_callchain_opt, "fp"),
+			     "mode[,dump_size]", record_callchain_help,
+			     &record_parse_callchain_opt, "fp"),
 	OPT_INCR('v', "verbose", &verbose,
 		    "be more verbose (show counter open errors, etc)"),
 	OPT_BOOLEAN('q', "quiet", &quiet, "don't print any message"),

tools/perf/util/callchain.h

@@ -143,4 +143,9 @@ static inline void callchain_cursor_advance(struct callchain_cursor *cursor)
 	cursor->curr = cursor->curr->next;
 	cursor->pos++;
 }
+
+struct option;
+
+int record_parse_callchain_opt(const struct option *opt, const char *arg, int unset);
+extern const char record_callchain_help[];
 #endif	/* __PERF_CALLCHAIN_H */