perf config: Add support setting variables in a config file

[mirror_ubuntu-artful-kernel.git] / tools / perf / builtin-config.c

diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
index e4207a23b52c0924e1d5c119f888467f7e9f1150..7c861b54f3a640b084f1237c61f061a11acca83c 100644 (file)
--- a/tools/perf/builtin-config.c
+++ b/tools/perf/builtin-config.c
@@ -17,7 +17,7 @@
 static bool use_system_config, use_user_config;
 
 static const char * const config_usage[] = {
-       "perf config [<file-option>] [options]",
+       "perf config [<file-option>] [options] [section.name[=value] ...]",
        NULL
 };
 
@@ -33,6 +33,69 @@ static struct option config_options[] = {
        OPT_END()
 };
 
+static int set_config(struct perf_config_set *set, const char *file_name,
+                     const char *var, const char *value)
+{
+       struct perf_config_section *section = NULL;
+       struct perf_config_item *item = NULL;
+       const char *first_line = "# this file is auto-generated.";
+       FILE *fp;
+
+       if (set == NULL)
+               return -1;
+
+       fp = fopen(file_name, "w");
+       if (!fp)
+               return -1;
+
+       perf_config_set__collect(set, var, value);
+       fprintf(fp, "%s\n", first_line);
+
+       /* overwrite configvariables */
+       perf_config_items__for_each_entry(&set->sections, section) {
+               fprintf(fp, "[%s]\n", section->name);
+
+               perf_config_items__for_each_entry(&section->items, item) {
+                       if (item->value)
+                               fprintf(fp, "\t%s = %s\n",
+                                       item->name, item->value);
+               }
+       }
+       fclose(fp);
+
+       return 0;
+}
+
+static int show_spec_config(struct perf_config_set *set, const char *var)
+{
+       struct perf_config_section *section;
+       struct perf_config_item *item;
+
+       if (set == NULL)
+               return -1;
+
+       perf_config_items__for_each_entry(&set->sections, section) {
+               if (prefixcmp(var, section->name) != 0)
+                       continue;
+
+               perf_config_items__for_each_entry(&section->items, item) {
+                       const char *name = var + strlen(section->name) + 1;
+
+                       if (strcmp(name, item->name) == 0) {
+                               char *value = item->value;
+
+                               if (value) {
+                                       printf("%s=%s\n", var, value);
+                                       return 0;
+                               }
+                       }
+
+               }
+       }
+
+       return 0;
+}
+
 static int show_config(struct perf_config_set *set)
 {
        struct perf_config_section *section;
@@ -52,9 +115,44 @@ static int show_config(struct perf_config_set *set)
        return 0;
 }
 
+static int parse_config_arg(char *arg, char **var, char **value)
+{
+       const char *last_dot = strchr(arg, '.');
+
+       /*
+        * Since "var" actually contains the section name and the real
+        * config variable name separated by a dot, we have to know where the dot is.
+        */
+       if (last_dot == NULL || last_dot == arg) {
+               pr_err("The config variable does not contain a section name: %s\n", arg);
+               return -1;
+       }
+       if (!last_dot[1]) {
+               pr_err("The config variable does not contain a variable name: %s\n", arg);
+               return -1;
+       }
+
+       *value = strchr(arg, '=');
+       if (*value == NULL)
+               *var = arg;
+       else if (!strcmp(*value, "=")) {
+               pr_err("The config variable does not contain a value: %s\n", arg);
+               return -1;
+       } else {
+               *value = *value + 1; /* excluding a first character '=' */
+               *var = strsep(&arg, "=");
+               if (*var[0] == '\0') {
+                       pr_err("invalid config variable: %s\n", arg);
+                       return -1;
+               }
+       }
+
+       return 0;
+}
+
 int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
 {
-       int ret = 0;
+       int i, ret = 0;
        struct perf_config_set *set;
        char *user_config = mkpath("%s/.perfconfig", getenv("HOME"));
 
@@ -100,7 +198,36 @@ int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
                }
                break;
        default:
-               usage_with_options(config_usage, config_options);
+               if (argc) {
+                       for (i = 0; argv[i]; i++) {
+                               char *var, *value;
+                               char *arg = strdup(argv[i]);
+
+                               if (!arg) {
+                                       pr_err("%s: strdup failed\n", __func__);
+                                       ret = -1;
+                                       break;
+                               }
+
+                               if (parse_config_arg(arg, &var, &value) < 0) {
+                                       free(arg);
+                                       ret = -1;
+                                       break;
+                               }
+
+                               if (value == NULL)
+                                       ret = show_spec_config(set, var);
+                               else {
+                                       const char *config_filename = config_exclusive_filename;
+
+                                       if (!config_exclusive_filename)
+                                               config_filename = user_config;
+                                       ret = set_config(set, config_filename, var, value);
+                               }
+                               free(arg);
+                       }
+               } else
+                       usage_with_options(config_usage, config_options);
        }
 
        perf_config_set__delete(set);