perf symbols: Introduce symbol__elf_init()

The symbol__elf_init() is for initializing internal libelf data
structure and getting rid of its dependency outside of ELF/symboling
handling code.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1344228082-15569-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-buildid-list.c

@@ -16,8 +16,6 @@
 #include "util/session.h"
 #include "util/symbol.h"
 
-#include <libelf.h>
-
 static const char *input_name;
 static bool force;
 static bool show_kernel;
@@ -71,7 +69,7 @@ static int perf_session__list_build_ids(void)
 {
 	struct perf_session *session;
 
-	elf_version(EV_CURRENT);
+	symbol__elf_init();
 
 	session = perf_session__new(input_name, O_RDONLY, force, false,
 				    &build_id__mark_dso_hit_ops);

tools/perf/util/symbol.c

@@ -1453,6 +1453,11 @@ out_close:
 	return err;
 }
 
+void symbol__elf_init(void)
+{
+	elf_version(EV_CURRENT);
+}
+
 static bool dso__build_id_equal(const struct dso *dso, u8 *build_id)
 {
 	return memcmp(dso->build_id, build_id, sizeof(dso->build_id)) == 0;
@@ -2754,7 +2759,8 @@ int symbol__init(void)
 
 	symbol_conf.priv_size = ALIGN(symbol_conf.priv_size, sizeof(u64));
 
-	elf_version(EV_CURRENT);
+	symbol__elf_init();
+
 	if (symbol_conf.sort_by_name)
 		symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
 					  sizeof(struct symbol));

tools/perf/util/symbol.h

@@ -309,6 +309,7 @@ void machines__destroy_guest_kernel_maps(struct rb_root *machines);
 
 int symbol__init(void);
 void symbol__exit(void);
+void symbol__elf_init(void);
 size_t symbol__fprintf_symname_offs(const struct symbol *sym,
 				    const struct addr_location *al, FILE *fp);
 size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp);