kernel/tools/perf/builtin-config.c

// SPDX-License-Identifier: GPL-2.0
/*
 * builtin-config.c
 *
 * Copyright (C) 2015, Taeung Song <treeze.taeung@gmail.com>
 *
 */
#include "builtin.h"

#include "util/cache.h"
#include <subcmd/parse-options.h>
#include "util/debug.h"
#include "util/config.h"
#include <linux/string.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>

static bool use_system_config, use_user_config;

static const char * const config_usage[] = {
	"perf config [<file-option>] [options] [section.name[=value] ...]",
	NULL
};

enum actions {
	ACTION_LIST = 1
} actions;

static struct option config_options[] = {
	OPT_SET_UINT('l', "list", &actions,
		     "show current config variables", ACTION_LIST),
	OPT_BOOLEAN(0, "system", &use_system_config, "use system config file"),
	OPT_BOOLEAN(0, "user", &use_user_config, "use user config file"),
	OPT_END()
};

static int set_config(struct perf_config_set *set, const char *file_name)
{
	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;

	fprintf(fp, "%s\n", first_line);

	/* overwrite configvariables */
	perf_config_items__for_each_entry(&set->sections, section) {
		if (!use_system_config && section->from_system_config)
			continue;
		fprintf(fp, "[%s]\n", section->name);

		perf_config_items__for_each_entry(&section->items, item) {
			if (!use_system_config && item->from_system_config)
				continue;
			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 (!strstarts(var, section->name))
			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;
	struct perf_config_item *item;

	if (set == NULL)
		return -1;

	perf_config_set__for_each_entry(set, section, item) {
		char *value = item->value;

		if (value)
			printf("%s.%s=%s\n", section->name,
			       item->name, value);
	}

	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)
{
	int i, ret = -1;
	struct perf_config_set *set;
	char path[PATH_MAX];
	char *user_config = mkpath(path, sizeof(path), "%s/.perfconfig", getenv("HOME"));
	const char *config_filename;
	bool changed = false;

	argc = parse_options(argc, argv, config_options, config_usage,
			     PARSE_OPT_STOP_AT_NON_OPTION);

	if (use_system_config && use_user_config) {
		pr_err("Error: only one config file at a time\n");
		parse_options_usage(config_usage, config_options, "user", 0);
		parse_options_usage(NULL, config_options, "system", 0);
		return -1;
	}

	if (use_system_config)
		config_exclusive_filename = perf_etc_perfconfig();
	else if (use_user_config)
		config_exclusive_filename = user_config;

	if (!config_exclusive_filename)
		config_filename = user_config;
	else
		config_filename = config_exclusive_filename;

	/*
	 * At only 'config' sub-command, individually use the config set
	 * because of reinitializing with options config file location.
	 */
	set = perf_config_set__new();
	if (!set)
		goto out_err;

	switch (actions) {
	case ACTION_LIST:
		if (argc) {
			pr_err("Error: takes no arguments\n");
			parse_options_usage(config_usage, config_options, "l", 1);
		} else {
do_action_list:
			if (show_config(set) < 0) {
				pr_err("Nothing configured, "
				       "please check your %s \n", config_filename);
				goto out_err;
			}
		}
		break;
	default:
		if (!argc)
			goto do_action_list;

		for (i = 0; argv[i]; i++) {
			char *var, *value;
			char *arg = strdup(argv[i]);

			if (!arg) {
				pr_err("%s: strdup failed\n", __func__);
				goto out_err;
			}

			if (parse_config_arg(arg, &var, &value) < 0) {
				free(arg);
				goto out_err;
			}

			if (value == NULL) {
				if (show_spec_config(set, var) < 0) {
					pr_err("%s is not configured: %s\n",
					       var, config_filename);
					free(arg);
					goto out_err;
				}
			} else {
				if (perf_config_set__collect(set, config_filename,
							     var, value) < 0) {
					pr_err("Failed to add '%s=%s'\n",
					       var, value);
					free(arg);
					goto out_err;
				}
				changed = true;
			}
			free(arg);
		}

		if (!changed)
			break;

		if (set_config(set, config_filename) < 0) {
			pr_err("Failed to set the configs on %s\n",
			       config_filename);
			goto out_err;
		}
	}

	ret = 0;
out_err:
	perf_config_set__delete(set);
	return ret;
}