perf tools: Consolidate management of default sort orders

The perf uses different default sort orders for different use-cases,
and this was scattered throughout the code. Add get_default_sort_
order() function to handle this and change initial value of sort_order
to NULL to distinguish it from user-given one.

Signed-off-by: Namhyung Kim <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Jiri Olsa <[e-mail]>

tools/perf/builtin-diff.c

···
 #define data__for_each_file(i, d) data__for_each_file_start(i, d, 0)
 #define data__for_each_file_new(i, d) data__for_each_file_start(i, d, 1)
 
-static char diff__default_sort_order[] = "dso,symbol";
 static bool force;
 static bool show_period;
 static bool show_formula;
···
 {
 	perf_config(perf_default_config, NULL);
 
-	sort_order = diff__default_sort_order;
 	argc = parse_options(argc, argv, options, diff_usage, 0);
 
 	if (symbol__init() < 0)
···
 		return -1;
 
 	ui_init();
+
+	sort__mode = SORT_MODE__DIFF;
 
 	if (setup_sorting() < 0)
 		usage_with_options(diff_usage, options);

tools/perf/builtin-report.c

···
 	if (branch_mode == -1 && has_br_stack)
 		sort__mode = SORT_MODE__BRANCH;
 
-	/* sort__mode could be NORMAL if --no-branch-stack */
-	if (sort__mode == SORT_MODE__BRANCH) {
-		/*
-		 * if no sort_order is provided, then specify
-		 * branch-mode specific order
-		 */
-		if (sort_order == default_sort_order)
-			sort_order = "comm,dso_from,symbol_from,"
-				     "dso_to,symbol_to";
-
-	}
 	if (report.mem_mode) {
 		if (sort__mode == SORT_MODE__BRANCH) {
 			pr_err("branch and mem mode incompatible\n");
 			goto error;
 		}
 		sort__mode = SORT_MODE__MEMORY;
-
-		/*
-		 * if no sort_order is provided, then specify
-		 * branch-mode specific order
-		 */
-		if (sort_order == default_sort_order)
-			sort_order = "local_weight,mem,sym,dso,symbol_daddr,dso_daddr,snoop,tlb,locked";
 	}
 
 	if (setup_sorting() < 0) {

tools/perf/builtin-top.c

···
 	if (argc)
 		usage_with_options(top_usage, options);
 
-	if (sort_order == default_sort_order)
-		sort_order = "dso,symbol";
+	sort__mode = SORT_MODE__TOP;
 
 	if (setup_sorting() < 0) {
 		parse_options_usage(top_usage, options, "s", 1);

tools/perf/util/sort.c

···
 const char	default_parent_pattern[] = "^sys_|^do_page_fault";
 const char	*parent_pattern = default_parent_pattern;
 const char	default_sort_order[] = "comm,dso,symbol";
-const char	*sort_order = default_sort_order;
+const char	default_branch_sort_order[] = "comm,dso_from,symbol_from,dso_to,symbol_to";
+const char	default_mem_sort_order[] = "local_weight,mem,sym,dso,symbol_daddr,dso_daddr,snoop,tlb,locked";
+const char	default_top_sort_order[] = "dso,symbol";
+const char	default_diff_sort_order[] = "dso,symbol";
+const char	*sort_order;
 regex_t		ignore_callees_regex;
 int		have_ignore_callees = 0;
 int		sort__need_collapse = 0;
···
 	return -ESRCH;
 }
 
+static const char *get_default_sort_order(void)
+{
+	const char *default_sort_orders[] = {
+		default_sort_order,
+		default_branch_sort_order,
+		default_mem_sort_order,
+		default_top_sort_order,
+		default_diff_sort_order,
+	};
+
+	BUG_ON(sort__mode >= ARRAY_SIZE(default_sort_orders));
+
+	return default_sort_orders[sort__mode];
+}
+
 int setup_sorting(void)
 {
-	char *tmp, *tok, *str = strdup(sort_order);
+	char *tmp, *tok, *str;
+	const char *sort_keys = sort_order;
 	int ret = 0;
 
+	if (sort_keys == NULL)
+		sort_keys = get_default_sort_order();
+
+	str = strdup(sort_keys);
 	if (str == NULL) {
 		error("Not enough memory to setup sort keys");
 		return -ENOMEM;

tools/perf/util/sort.h

···
 	SORT_MODE__NORMAL,
 	SORT_MODE__BRANCH,
 	SORT_MODE__MEMORY,
+	SORT_MODE__TOP,
+	SORT_MODE__DIFF,
 };
 
 enum sort_type {