[PATCH -tip] perf tools: Don't allow empty argument for field-separator.

[Wang Nan <wangnan0@huawei.com>]

Both 'perf diff' and 'perf mem' have 'field-separator' option, which
causes segfault if passed with empty string. This patch uses previously
introduced 'OPT_STRING_NOEMPTY' option macro to prevent fault.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
This patch is based on Arnaldo's pull request for Ingo:
  Commit 0c8c20779c5d56b93b8cb4cd30ba129a927ab437
---
 tools/perf/builtin-diff.c | 2 +-
 tools/perf/builtin-mem.c  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index f800fc9..473887d 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -802,7 +802,7 @@ static const struct option options[] = {
 	OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
 		   "sort by key(s): pid, comm, dso, symbol, parent, cpu, srcline, ..."
 		   " Please refer the man page for the complete list."),
-	OPT_STRING('t', "field-separator", &symbol_conf.field_sep, "separator",
+	OPT_STRING_NOEMPTY('t', "field-separator", &symbol_conf.field_sep, "separator",
 		   "separator for columns, no spaces will be added between "
 		   "columns '.' is reserved."),
 	OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
diff --git a/tools/perf/builtin-mem.c b/tools/perf/builtin-mem.c
index 46c6931..b4dcf0b 100644
--- a/tools/perf/builtin-mem.c
+++ b/tools/perf/builtin-mem.c
@@ -286,7 +286,7 @@ int cmd_mem(int argc, const char **argv, const char *prefix __maybe_unused)
 		   "input file name"),
 	OPT_STRING('C', "cpu", &mem.cpu_list, "cpu",
 		   "list of cpus to profile"),
-	OPT_STRING('x', "field-separator", &symbol_conf.field_sep,
+	OPT_STRING_NOEMPTY('x', "field-separator", &symbol_conf.field_sep,
 		   "separator",
 		   "separator for columns, no spaces will be added"
 		   " between columns '.' is reserved."),
-- 
1.8.3.4