perf report: Add --no-demangle option

It's sometimes useful to see undemangled raw symbol name for example
other tools using the perf output to do manipulation of binaries.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Suggested-by: William Cohen <wcohen@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: William Cohen <wcohen@redhat.com>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=55571
Link: http://lkml.kernel.org/r/1364203098-17741-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 54efcb5..4b12bf8 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -806,9 +806,12 @@
 		 * DWARF DW_compile_unit has this, but we don't always have access
 		 * to it...
 		 */
-		demangled = bfd_demangle(NULL, elf_name, DMGL_PARAMS | DMGL_ANSI);
-		if (demangled != NULL)
-			elf_name = demangled;
+		if (symbol_conf.demangle) {
+			demangled = bfd_demangle(NULL, elf_name,
+						 DMGL_PARAMS | DMGL_ANSI);
+			if (demangled != NULL)
+				elf_name = demangled;
+		}
 new_symbol:
 		f = symbol__new(sym.st_value, sym.st_size,
 				GELF_ST_BIND(sym.st_info), elf_name);