/*

   * config.c
   *
   * Helper functions for parsing config items.
   * Originally copied from GIT source.

   *
   * Copyright (C) Linus Torvalds, 2005
   * Copyright (C) Johannes Schindelin, 2005
   *
   */

  #include <errno.h>

  #include <sys/param.h>

  #include "util.h"
  #include "cache.h"

  #include <subcmd/exec-cmd.h>

  #include "util/hist.h"  /* perf_hist_config */

  #include "util/llvm-utils.h"   /* perf_llvm_config */

  #include "config.h"

  #include <sys/types.h>
  #include <sys/stat.h>
  #include <unistd.h>

  #include "sane_ctype.h"

  #define MAXNAME (256)

  #define DEBUG_CACHE_DIR ".debug"
  
  
  char buildid_dir[MAXPATHLEN]; /* root dir for buildid, binary cache */

  static FILE *config_file;
  static const char *config_file_name;
  static int config_linenr;
  static int config_file_eof;

  static struct perf_config_set *config_set;

  const char *config_exclusive_filename;

  
  static int get_next_char(void)
  {
  	int c;
  	FILE *f;
  
  	c = '
  ';
  	if ((f = config_file) != NULL) {
  		c = fgetc(f);
  		if (c == '\r') {
  			/* DOS like systems */
  			c = fgetc(f);
  			if (c != '
  ') {
  				ungetc(c, f);
  				c = '\r';
  			}
  		}
  		if (c == '
  ')
  			config_linenr++;
  		if (c == EOF) {
  			config_file_eof = 1;
  			c = '
  ';
  		}
  	}
  	return c;
  }
  
  static char *parse_value(void)
  {
  	static char value[1024];

  	int quote = 0, comment = 0, space = 0;
  	size_t len = 0;

  
  	for (;;) {
  		int c = get_next_char();

  		if (len >= sizeof(value) - 1)
  			return NULL;
  		if (c == '
  ') {
  			if (quote)
  				return NULL;
  			value[len] = 0;
  			return value;
  		}
  		if (comment)
  			continue;
  		if (isspace(c) && !quote) {
  			space = 1;
  			continue;
  		}
  		if (!quote) {
  			if (c == ';' || c == '#') {
  				comment = 1;
  				continue;
  			}
  		}
  		if (space) {
  			if (len)
  				value[len++] = ' ';
  			space = 0;
  		}
  		if (c == '\\') {
  			c = get_next_char();
  			switch (c) {
  			case '
  ':
  				continue;
  			case 't':
  				c = '\t';
  				break;
  			case 'b':
  				c = '\b';
  				break;
  			case 'n':
  				c = '
  ';
  				break;
  			/* Some characters escape as themselves */
  			case '\\': case '"':
  				break;
  			/* Reject unknown escape sequences */
  			default:
  				return NULL;
  			}
  			value[len++] = c;
  			continue;
  		}
  		if (c == '"') {
  			quote = 1-quote;
  			continue;
  		}
  		value[len++] = c;
  	}
  }
  
  static inline int iskeychar(int c)
  {

  	return isalnum(c) || c == '-' || c == '_';

  }
  
  static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
  {
  	int c;
  	char *value;
  
  	/* Get the full name */
  	for (;;) {
  		c = get_next_char();
  		if (config_file_eof)
  			break;
  		if (!iskeychar(c))
  			break;

  		name[len++] = c;

  		if (len >= MAXNAME)
  			return -1;
  	}
  	name[len] = 0;
  	while (c == ' ' || c == '\t')
  		c = get_next_char();
  
  	value = NULL;
  	if (c != '
  ') {
  		if (c != '=')
  			return -1;
  		value = parse_value();
  		if (!value)
  			return -1;
  	}
  	return fn(name, value, data);
  }
  
  static int get_extended_base_var(char *name, int baselen, int c)
  {
  	do {
  		if (c == '
  ')
  			return -1;
  		c = get_next_char();
  	} while (isspace(c));
  
  	/* We require the format to be '[base "extension"]' */
  	if (c != '"')
  		return -1;
  	name[baselen++] = '.';
  
  	for (;;) {

  		int ch = get_next_char();
  
  		if (ch == '
  ')

  			return -1;

  		if (ch == '"')

  			break;

  		if (ch == '\\') {
  			ch = get_next_char();
  			if (ch == '
  ')

  				return -1;
  		}

  		name[baselen++] = ch;

  		if (baselen > MAXNAME / 2)
  			return -1;
  	}
  
  	/* Final ']' */
  	if (get_next_char() != ']')
  		return -1;
  	return baselen;
  }
  
  static int get_base_var(char *name)
  {
  	int baselen = 0;
  
  	for (;;) {
  		int c = get_next_char();
  		if (config_file_eof)
  			return -1;
  		if (c == ']')
  			return baselen;
  		if (isspace(c))
  			return get_extended_base_var(name, baselen, c);
  		if (!iskeychar(c) && c != '.')
  			return -1;
  		if (baselen > MAXNAME / 2)
  			return -1;
  		name[baselen++] = tolower(c);
  	}
  }
  
  static int perf_parse_file(config_fn_t fn, void *data)
  {
  	int comment = 0;
  	int baselen = 0;
  	static char var[MAXNAME];
  
  	/* U+FEFF Byte Order Mark in UTF8 */
  	static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
  	const unsigned char *bomptr = utf8_bom;
  
  	for (;;) {

  		int line, c = get_next_char();

  		if (bomptr && *bomptr) {
  			/* We are at the file beginning; skip UTF8-encoded BOM
  			 * if present. Sane editors won't put this in on their
  			 * own, but e.g. Windows Notepad will do it happily. */
  			if ((unsigned char) c == *bomptr) {
  				bomptr++;
  				continue;
  			} else {
  				/* Do not tolerate partial BOM. */
  				if (bomptr != utf8_bom)
  					break;
  				/* No BOM at file beginning. Cool. */
  				bomptr = NULL;
  			}
  		}
  		if (c == '
  ') {
  			if (config_file_eof)
  				return 0;
  			comment = 0;
  			continue;
  		}
  		if (comment || isspace(c))
  			continue;
  		if (c == '#' || c == ';') {
  			comment = 1;
  			continue;
  		}
  		if (c == '[') {
  			baselen = get_base_var(var);
  			if (baselen <= 0)
  				break;
  			var[baselen++] = '.';
  			var[baselen] = 0;
  			continue;
  		}
  		if (!isalpha(c))
  			break;
  		var[baselen] = tolower(c);

  
  		/*
  		 * The get_value function might or might not reach the '
  ',
  		 * so saving the current line number for error reporting.
  		 */
  		line = config_linenr;
  		if (get_value(fn, data, var, baselen+1) < 0) {
  			config_linenr = line;

  			break;

  		}

  	}

  	pr_err("bad config file line %d in %s
  ", config_linenr, config_file_name);
  	return -1;

  }
  
  static int parse_unit_factor(const char *end, unsigned long *val)
  {
  	if (!*end)
  		return 1;
  	else if (!strcasecmp(end, "k")) {
  		*val *= 1024;
  		return 1;
  	}
  	else if (!strcasecmp(end, "m")) {
  		*val *= 1024 * 1024;
  		return 1;
  	}
  	else if (!strcasecmp(end, "g")) {
  		*val *= 1024 * 1024 * 1024;
  		return 1;
  	}
  	return 0;
  }

  static int perf_parse_llong(const char *value, long long *ret)
  {
  	if (value && *value) {
  		char *end;
  		long long val = strtoll(value, &end, 0);
  		unsigned long factor = 1;
  
  		if (!parse_unit_factor(end, &factor))
  			return 0;
  		*ret = val * factor;
  		return 1;
  	}
  	return 0;
  }

  static int perf_parse_long(const char *value, long *ret)
  {
  	if (value && *value) {
  		char *end;
  		long val = strtol(value, &end, 0);
  		unsigned long factor = 1;
  		if (!parse_unit_factor(end, &factor))
  			return 0;
  		*ret = val * factor;
  		return 1;
  	}
  	return 0;
  }

  static void die_bad_config(const char *name)
  {
  	if (config_file_name)
  		die("bad config value for '%s' in %s", name, config_file_name);
  	die("bad config value for '%s'", name);
  }

  u64 perf_config_u64(const char *name, const char *value)
  {
  	long long ret = 0;
  
  	if (!perf_parse_llong(value, &ret))
  		die_bad_config(name);
  	return (u64) ret;
  }

  int perf_config_int(const char *name, const char *value)
  {
  	long ret = 0;
  	if (!perf_parse_long(value, &ret))
  		die_bad_config(name);
  	return ret;
  }

  static int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)

  {
  	*is_bool = 1;
  	if (!value)
  		return 1;
  	if (!*value)
  		return 0;
  	if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
  		return 1;
  	if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
  		return 0;
  	*is_bool = 0;
  	return perf_config_int(name, value);
  }
  
  int perf_config_bool(const char *name, const char *value)
  {
  	int discard;
  	return !!perf_config_bool_or_int(name, value, &discard);
  }

  static const char *perf_config_dirname(const char *name, const char *value)

  {
  	if (!name)
  		return NULL;
  	return value;
  }

  static int perf_buildid_config(const char *var, const char *value)
  {
  	/* same dir for all commands */
  	if (!strcmp(var, "buildid.dir")) {

  		const char *dir = perf_config_dirname(var, value);

  		if (!dir) {
  			pr_err("Invalid buildid directory!
  ");

  			return -1;

  		}

  		strncpy(buildid_dir, dir, MAXPATHLEN-1);

  		buildid_dir[MAXPATHLEN-1] = '\0';
  	}
  
  	return 0;
  }

  static int perf_default_core_config(const char *var __maybe_unused,
  				    const char *value __maybe_unused)

  {

  	/* Add other config variables here. */

  	return 0;
  }

  static int perf_ui_config(const char *var, const char *value)
  {
  	/* Add other config variables here. */

  	if (!strcmp(var, "ui.show-headers"))

  		symbol_conf.show_hist_headers = perf_config_bool(var, value);

  	return 0;
  }

  int perf_default_config(const char *var, const char *value,
  			void *dummy __maybe_unused)

  {
  	if (!prefixcmp(var, "core."))
  		return perf_default_core_config(var, value);

  	if (!prefixcmp(var, "hist."))
  		return perf_hist_config(var, value);

  	if (!prefixcmp(var, "ui."))
  		return perf_ui_config(var, value);

  	if (!prefixcmp(var, "call-graph."))
  		return perf_callchain_config(var, value);

  	if (!prefixcmp(var, "llvm."))
  		return perf_llvm_config(var, value);

  	if (!prefixcmp(var, "buildid."))
  		return perf_buildid_config(var, value);

  	/* Add other config variables here. */

  	return 0;
  }

  static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)

  {
  	int ret;
  	FILE *f = fopen(filename, "r");
  
  	ret = -1;
  	if (f) {
  		config_file = f;
  		config_file_name = filename;
  		config_linenr = 1;
  		config_file_eof = 0;
  		ret = perf_parse_file(fn, data);
  		fclose(f);
  		config_file_name = NULL;
  	}
  	return ret;
  }

  const char *perf_etc_perfconfig(void)

  {
  	static const char *system_wide;
  	if (!system_wide)
  		system_wide = system_path(ETC_PERFCONFIG);
  	return system_wide;
  }
  
  static int perf_env_bool(const char *k, int def)
  {
  	const char *v = getenv(k);
  	return v ? perf_config_bool(k, v) : def;
  }

  static int perf_config_system(void)

  {
  	return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
  }

  static int perf_config_global(void)

  {
  	return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
  }

  static struct perf_config_section *find_section(struct list_head *sections,
  						const char *section_name)
  {
  	struct perf_config_section *section;
  
  	list_for_each_entry(section, sections, node)
  		if (!strcmp(section->name, section_name))
  			return section;
  
  	return NULL;
  }
  
  static struct perf_config_item *find_config_item(const char *name,
  						 struct perf_config_section *section)
  {
  	struct perf_config_item *item;
  
  	list_for_each_entry(item, &section->items, node)
  		if (!strcmp(item->name, name))
  			return item;
  
  	return NULL;
  }
  
  static struct perf_config_section *add_section(struct list_head *sections,
  					       const char *section_name)
  {
  	struct perf_config_section *section = zalloc(sizeof(*section));
  
  	if (!section)
  		return NULL;
  
  	INIT_LIST_HEAD(&section->items);
  	section->name = strdup(section_name);
  	if (!section->name) {
  		pr_debug("%s: strdup failed
  ", __func__);
  		free(section);
  		return NULL;
  	}
  
  	list_add_tail(&section->node, sections);
  	return section;
  }
  
  static struct perf_config_item *add_config_item(struct perf_config_section *section,
  						const char *name)
  {
  	struct perf_config_item *item = zalloc(sizeof(*item));
  
  	if (!item)
  		return NULL;
  
  	item->name = strdup(name);
  	if (!item->name) {
  		pr_debug("%s: strdup failed
  ", __func__);
  		free(item);
  		return NULL;
  	}
  
  	list_add_tail(&item->node, &section->items);
  	return item;
  }
  
  static int set_value(struct perf_config_item *item, const char *value)
  {
  	char *val = strdup(value);
  
  	if (!val)
  		return -1;
  
  	zfree(&item->value);
  	item->value = val;
  	return 0;
  }
  
  static int collect_config(const char *var, const char *value,
  			  void *perf_config_set)
  {
  	int ret = -1;
  	char *ptr, *key;
  	char *section_name, *name;
  	struct perf_config_section *section = NULL;
  	struct perf_config_item *item = NULL;
  	struct perf_config_set *set = perf_config_set;

  	struct list_head *sections;

  	if (set == NULL)
  		return -1;
  
  	sections = &set->sections;

  	key = ptr = strdup(var);
  	if (!key) {
  		pr_debug("%s: strdup failed
  ", __func__);
  		return -1;
  	}
  
  	section_name = strsep(&ptr, ".");
  	name = ptr;
  	if (name == NULL || value == NULL)
  		goto out_free;
  
  	section = find_section(sections, section_name);
  	if (!section) {
  		section = add_section(sections, section_name);
  		if (!section)
  			goto out_free;
  	}
  
  	item = find_config_item(name, section);
  	if (!item) {
  		item = add_config_item(section, name);
  		if (!item)
  			goto out_free;
  	}

  	/* perf_config_set can contain both user and system config items.
  	 * So we should know where each value is from.
  	 * The classification would be needed when a particular config file
  	 * is overwrited by setting feature i.e. set_config().
  	 */
  	if (strcmp(config_file_name, perf_etc_perfconfig()) == 0) {
  		section->from_system_config = true;
  		item->from_system_config = true;
  	} else {
  		section->from_system_config = false;
  		item->from_system_config = false;
  	}

  	ret = set_value(item, value);
  	return ret;
  
  out_free:
  	free(key);

  	return -1;
  }

  int perf_config_set__collect(struct perf_config_set *set, const char *file_name,

  			     const char *var, const char *value)
  {

  	config_file_name = file_name;

  	return collect_config(var, value, set);
  }

  static int perf_config_set__init(struct perf_config_set *set)
  {
  	int ret = -1;
  	const char *home = NULL;

  	char *user_config;
  	struct stat st;

  
  	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
  	if (config_exclusive_filename)
  		return perf_config_from_file(collect_config, config_exclusive_filename, set);
  	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
  		if (perf_config_from_file(collect_config, perf_etc_perfconfig(), set) < 0)
  			goto out;
  	}
  
  	home = getenv("HOME");

  	/*
  	 * Skip reading user config if:
  	 *   - there is no place to read it from (HOME)
  	 *   - we are asked not to (PERF_CONFIG_NOGLOBAL=1)
  	 */
  	if (!home || !*home || !perf_config_global())
  		return 0;

  	user_config = strdup(mkpath("%s/.perfconfig", home));
  	if (user_config == NULL) {
  		warning("Not enough memory to process %s/.perfconfig, "
  			"ignoring it.", home);
  		goto out;
  	}
  
  	if (stat(user_config, &st) < 0) {
  		if (errno == ENOENT)
  			ret = 0;
  		goto out_free;
  	}

  	ret = 0;

  	if (st.st_uid && (st.st_uid != geteuid())) {
  		warning("File %s not owned by current user or root, "
  			"ignoring it.", user_config);
  		goto out_free;
  	}
  
  	if (st.st_size)
  		ret = perf_config_from_file(collect_config, user_config, set);

  out_free:

  	free(user_config);

  out:
  	return ret;
  }

  struct perf_config_set *perf_config_set__new(void)
  {
  	struct perf_config_set *set = zalloc(sizeof(*set));
  
  	if (set) {
  		INIT_LIST_HEAD(&set->sections);

  		if (perf_config_set__init(set) < 0) {

  			perf_config_set__delete(set);
  			set = NULL;
  		}

  	}
  
  	return set;
  }

  int perf_config(config_fn_t fn, void *data)
  {
  	int ret = 0;
  	char key[BUFSIZ];
  	struct perf_config_section *section;
  	struct perf_config_item *item;
  
  	if (config_set == NULL)
  		return -1;
  
  	perf_config_set__for_each_entry(config_set, section, item) {
  		char *value = item->value;
  
  		if (value) {
  			scnprintf(key, sizeof(key), "%s.%s",
  				  section->name, item->name);
  			ret = fn(key, value, data);
  			if (ret < 0) {
  				pr_err("Error: wrong config key-value pair %s=%s
  ",
  				       key, value);
  				break;
  			}
  		}
  	}
  
  	return ret;
  }
  
  void perf_config__init(void)
  {
  	if (config_set == NULL)
  		config_set = perf_config_set__new();
  }
  
  void perf_config__exit(void)
  {
  	perf_config_set__delete(config_set);
  	config_set = NULL;
  }
  
  void perf_config__refresh(void)
  {
  	perf_config__exit();
  	perf_config__init();
  }

  static void perf_config_item__delete(struct perf_config_item *item)
  {
  	zfree(&item->name);
  	zfree(&item->value);
  	free(item);
  }
  
  static void perf_config_section__purge(struct perf_config_section *section)
  {
  	struct perf_config_item *item, *tmp;
  
  	list_for_each_entry_safe(item, tmp, &section->items, node) {
  		list_del_init(&item->node);
  		perf_config_item__delete(item);
  	}
  }
  
  static void perf_config_section__delete(struct perf_config_section *section)
  {
  	perf_config_section__purge(section);
  	zfree(&section->name);
  	free(section);
  }
  
  static void perf_config_set__purge(struct perf_config_set *set)
  {
  	struct perf_config_section *section, *tmp;
  
  	list_for_each_entry_safe(section, tmp, &set->sections, node) {
  		list_del_init(&section->node);
  		perf_config_section__delete(section);
  	}
  }
  
  void perf_config_set__delete(struct perf_config_set *set)
  {

  	if (set == NULL)
  		return;

  	perf_config_set__purge(set);
  	free(set);
  }

  /*

   * Call this to report error for your variable that should not
   * get a boolean value (i.e. "[my] var" means "true").
   */
  int config_error_nonbool(const char *var)
  {
  	return error("Missing value for '%s'", var);
  }

  void set_buildid_dir(const char *dir)

  {

  	if (dir)
  		scnprintf(buildid_dir, MAXPATHLEN-1, "%s", dir);

  	/* default to $HOME/.debug */
  	if (buildid_dir[0] == '\0') {

  		char *home = getenv("HOME");
  
  		if (home) {

  			snprintf(buildid_dir, MAXPATHLEN-1, "%s/%s",

  				 home, DEBUG_CACHE_DIR);

  		} else {
  			strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
  		}
  		buildid_dir[MAXPATHLEN-1] = '\0';
  	}
  	/* for communicating with external commands */
  	setenv("PERF_BUILDID_DIR", buildid_dir, 1);
  }