[PATCH v2 4/7] perf config: Parse arguments before setting functionality

[Taeung Song]

For upcoming setting functionality,
parse both config variables and values of arguments.
If setting the sort order of report functionality to srcline,

    # perf config report.sort-order=srcline

we can parse config variables and values with parse_config_arg()

Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Jiri Olsa <jo...@kernel.org>
Cc: Wang Nan <wangn...@huawei.com>
Signed-off-by: Taeung Song <treeze.tae...@gmail.com>
---
 tools/perf/builtin-config.c | 43 ++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 38 insertions(+), 5 deletions(-)

diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
index 02def73..098d2df 100644
--- a/tools/perf/builtin-config.c
+++ b/tools/perf/builtin-config.c
@@ -82,10 +82,10 @@ static int show_config(struct perf_config_set *set)
        return 0;
 }
 
-static int parse_config_arg(const char *arg, char **var)
+static int parse_config_arg(const char *arg, char **var, char **value)
 {
        const char *last_dot;
-       char *key;
+       char *key, *val;
 
        key = strdup(arg);
        if (!key) {
@@ -107,7 +107,37 @@ static int parse_config_arg(const char *arg, char **var)
                goto out_err;
        }
 
-       *var = key;
+       val = strchr(key, '=');
+       if (val == NULL) {
+               *var = key;
+               return 0;
+       } else if (!strcmp(val, "=")) {
+               pr_err("The config variable does not contain a value: %s\n", 
arg);
+               goto out_err;
+       } else {
+               char *v, *ptr;
+
+               *value = strdup(val + 1); /* excluding a first character '=' */
+               if (*value == NULL) {
+                       pr_err("%s: strdup failed\n", __func__);
+                       goto out_err;
+               }
+
+               ptr = key;
+               v = strsep(&key, "=");
+               if (v[0] == '\0') {
+                       pr_err("invalid config variable: %s\n", arg);
+                       goto out_err;
+               }
+
+               *var = strdup(v);
+               free(ptr);
+               if (*var == NULL) {
+                       pr_err("%s: strdup failed\n", __func__);
+                       return -1;
+               }
+       }
+
        return 0;
 out_err:
        free(key);
@@ -169,11 +199,14 @@ int cmd_config(int argc, const char **argv, const char 
*prefix __maybe_unused)
 
                for (i = 0; argv[i]; i++) {
                        char *var = NULL;
+                       char *value = NULL;
 
-                       if (parse_config_arg(argv[i], &var) < 0)
+                       if (parse_config_arg(argv[i], &var, &value) < 0)
                                break;
-                       ret = show_spec_config(set, var);
+                       if (value == NULL)
+                               ret = show_spec_config(set, var);
                        free(var);
+                       free(value);
                }
        }
 
-- 
2.7.4