/*
   * perf.c
   *
   * Performance analysis utility.
   *
   * This is the main hub from which the sub-commands (perf stat,
   * perf top, perf record, perf report, etc.) are started.
   */

  #include "builtin.h"

  #include "util/exec_cmd.h"
  #include "util/cache.h"
  #include "util/quote.h"
  #include "util/run-command.h"

  #include "util/parse-events.h"

  #include "util/debugfs.h"

  
  const char perf_usage_string[] =

  	"perf [--version] [--help] COMMAND [ARGS]";

  
  const char perf_more_info_string[] =
  	"See 'perf help COMMAND' for more information on a specific command.";

  int use_browser = -1;

  static int use_pager = -1;

  struct pager_config {
  	const char *cmd;
  	int val;
  };

  static char debugfs_mntpt[MAXPATHLEN];

  static int pager_command_config(const char *var, const char *value, void *data)
  {
  	struct pager_config *c = data;
  	if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd))
  		c->val = perf_config_bool(var, value);
  	return 0;
  }
  
  /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
  int check_pager_config(const char *cmd)
  {
  	struct pager_config c;
  	c.cmd = cmd;
  	c.val = -1;
  	perf_config(pager_command_config, &c);
  	return c.val;
  }

  static int tui_command_config(const char *var, const char *value, void *data)
  {
  	struct pager_config *c = data;
  	if (!prefixcmp(var, "tui.") && !strcmp(var + 4, c->cmd))
  		c->val = perf_config_bool(var, value);
  	return 0;
  }
  
  /* returns 0 for "no tui", 1 for "use tui", and -1 for "not specified" */
  static int check_tui_config(const char *cmd)
  {
  	struct pager_config c;
  	c.cmd = cmd;
  	c.val = -1;
  	perf_config(tui_command_config, &c);
  	return c.val;
  }

  static void commit_pager_choice(void)
  {

  	switch (use_pager) {
  	case 0:
  		setenv("PERF_PAGER", "cat", 1);
  		break;
  	case 1:
  		/* setup_pager(); */
  		break;
  	default:
  		break;
  	}
  }

  static void set_debugfs_path(void)
  {
  	char *path;
  
  	path = getenv(PERF_DEBUGFS_ENVIRONMENT);
  	snprintf(debugfs_path, MAXPATHLEN, "%s/%s", path ?: debugfs_mntpt,
  		 "tracing/events");
  }

  static int handle_options(const char ***argv, int *argc, int *envchanged)

  {
  	int handled = 0;
  
  	while (*argc > 0) {
  		const char *cmd = (*argv)[0];
  		if (cmd[0] != '-')
  			break;
  
  		/*
  		 * For legacy reasons, the "version" and "help"
  		 * commands can be written with "--" prepended
  		 * to make them look like flags.
  		 */
  		if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
  			break;
  
  		/*
  		 * Check remaining flags.
  		 */

  		if (!prefixcmp(cmd, CMD_EXEC_PATH)) {
  			cmd += strlen(CMD_EXEC_PATH);

  			if (*cmd == '=')
  				perf_set_argv_exec_path(cmd + 1);
  			else {
  				puts(perf_exec_path());
  				exit(0);
  			}
  		} else if (!strcmp(cmd, "--html-path")) {
  			puts(system_path(PERF_HTML_PATH));
  			exit(0);
  		} else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
  			use_pager = 1;
  		} else if (!strcmp(cmd, "--no-pager")) {
  			use_pager = 0;
  			if (envchanged)
  				*envchanged = 1;
  		} else if (!strcmp(cmd, "--perf-dir")) {
  			if (*argc < 2) {

  				fprintf(stderr, "No directory given for --perf-dir.
  ");

  				usage(perf_usage_string);
  			}
  			setenv(PERF_DIR_ENVIRONMENT, (*argv)[1], 1);
  			if (envchanged)
  				*envchanged = 1;
  			(*argv)++;
  			(*argc)--;
  			handled++;

  		} else if (!prefixcmp(cmd, CMD_PERF_DIR)) {
  			setenv(PERF_DIR_ENVIRONMENT, cmd + strlen(CMD_PERF_DIR), 1);

  			if (envchanged)
  				*envchanged = 1;
  		} else if (!strcmp(cmd, "--work-tree")) {
  			if (*argc < 2) {

  				fprintf(stderr, "No directory given for --work-tree.
  ");

  				usage(perf_usage_string);
  			}
  			setenv(PERF_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
  			if (envchanged)
  				*envchanged = 1;
  			(*argv)++;
  			(*argc)--;

  		} else if (!prefixcmp(cmd, CMD_WORK_TREE)) {
  			setenv(PERF_WORK_TREE_ENVIRONMENT, cmd + strlen(CMD_WORK_TREE), 1);

  			if (envchanged)
  				*envchanged = 1;

  		} else if (!strcmp(cmd, "--debugfs-dir")) {
  			if (*argc < 2) {
  				fprintf(stderr, "No directory given for --debugfs-dir.
  ");
  				usage(perf_usage_string);
  			}
  			strncpy(debugfs_mntpt, (*argv)[1], MAXPATHLEN);
  			debugfs_mntpt[MAXPATHLEN - 1] = '\0';
  			if (envchanged)
  				*envchanged = 1;
  			(*argv)++;
  			(*argc)--;

  		} else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
  			strncpy(debugfs_mntpt, cmd + strlen(CMD_DEBUGFS_DIR), MAXPATHLEN);

  			debugfs_mntpt[MAXPATHLEN - 1] = '\0';
  			if (envchanged)
  				*envchanged = 1;

  		} else {
  			fprintf(stderr, "Unknown option: %s
  ", cmd);
  			usage(perf_usage_string);
  		}
  
  		(*argv)++;
  		(*argc)--;
  		handled++;
  	}
  	return handled;
  }
  
  static int handle_alias(int *argcp, const char ***argv)
  {
  	int envchanged = 0, ret = 0, saved_errno = errno;
  	int count, option_count;

  	const char **new_argv;

  	const char *alias_command;
  	char *alias_string;

  
  	alias_command = (*argv)[0];
  	alias_string = alias_lookup(alias_command);
  	if (alias_string) {
  		if (alias_string[0] == '!') {
  			if (*argcp > 1) {
  				struct strbuf buf;
  
  				strbuf_init(&buf, PATH_MAX);
  				strbuf_addstr(&buf, alias_string);
  				sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
  				free(alias_string);
  				alias_string = buf.buf;
  			}
  			ret = system(alias_string + 1);
  			if (ret >= 0 && WIFEXITED(ret) &&
  			    WEXITSTATUS(ret) != 127)
  				exit(WEXITSTATUS(ret));
  			die("Failed to run '%s' when expanding alias '%s'",
  			    alias_string + 1, alias_command);
  		}
  		count = split_cmdline(alias_string, &new_argv);
  		if (count < 0)
  			die("Bad alias.%s string", alias_command);
  		option_count = handle_options(&new_argv, &count, &envchanged);
  		if (envchanged)
  			die("alias '%s' changes environment variables
  "
  				 "You can use '!perf' in the alias to do this.",
  				 alias_command);
  		memmove(new_argv - option_count, new_argv,
  				count * sizeof(char *));
  		new_argv -= option_count;
  
  		if (count < 1)
  			die("empty alias for %s", alias_command);
  
  		if (!strcmp(alias_command, new_argv[0]))
  			die("recursive alias: %s", alias_command);

  		new_argv = realloc(new_argv, sizeof(char *) *

  				    (count + *argcp + 1));
  		/* insert after command name */

  		memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
  		new_argv[count + *argcp] = NULL;

  
  		*argv = new_argv;
  		*argcp += count - 1;
  
  		ret = 1;
  	}
  
  	errno = saved_errno;
  
  	return ret;
  }
  
  const char perf_version_string[] = PERF_VERSION;
  
  #define RUN_SETUP	(1<<0)
  #define USE_PAGER	(1<<1)
  /*
   * require working tree to be present -- anything uses this needs
   * RUN_SETUP for reading from the configuration file.
   */
  #define NEED_WORK_TREE	(1<<2)
  
  struct cmd_struct {
  	const char *cmd;
  	int (*fn)(int, const char **, const char *);
  	int option;
  };
  
  static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
  {
  	int status;
  	struct stat st;
  	const char *prefix;
  
  	prefix = NULL;
  	if (p->option & RUN_SETUP)
  		prefix = NULL; /* setup_perf_directory(); */

  	if (use_browser == -1)
  		use_browser = check_tui_config(p->cmd);

  	if (use_pager == -1 && p->option & RUN_SETUP)
  		use_pager = check_pager_config(p->cmd);
  	if (use_pager == -1 && p->option & USE_PAGER)
  		use_pager = 1;
  	commit_pager_choice();

  	set_debugfs_path();

  	status = p->fn(argc, argv, prefix);

  	exit_browser(status);

  	if (status)
  		return status & 0xff;
  
  	/* Somebody closed stdout? */
  	if (fstat(fileno(stdout), &st))
  		return 0;
  	/* Ignore write errors for pipes and sockets.. */
  	if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
  		return 0;
  
  	/* Check for ENOSPC and EIO errors.. */
  	if (fflush(stdout))
  		die("write failure on standard output: %s", strerror(errno));
  	if (ferror(stdout))
  		die("unknown write failure on standard output");
  	if (fclose(stdout))
  		die("close failed on standard output: %s", strerror(errno));
  	return 0;
  }
  
  static void handle_internal_command(int argc, const char **argv)
  {
  	const char *cmd = argv[0];
  	static struct cmd_struct commands[] = {

  		{ "buildid-cache", cmd_buildid_cache, 0 },

  		{ "buildid-list", cmd_buildid_list, 0 },

  		{ "diff",	cmd_diff,	0 },

  		{ "help",	cmd_help,	0 },
  		{ "list",	cmd_list,	0 },
  		{ "record",	cmd_record,	0 },
  		{ "report",	cmd_report,	0 },
  		{ "bench",	cmd_bench,	0 },
  		{ "stat",	cmd_stat,	0 },
  		{ "timechart",	cmd_timechart,	0 },
  		{ "top",	cmd_top,	0 },
  		{ "annotate",	cmd_annotate,	0 },
  		{ "version",	cmd_version,	0 },
  		{ "trace",	cmd_trace,	0 },
  		{ "sched",	cmd_sched,	0 },
  		{ "probe",	cmd_probe,	0 },
  		{ "kmem",	cmd_kmem,	0 },

  		{ "lock",	cmd_lock,	0 },

  		{ "kvm",	cmd_kvm,	0 },

  		{ "test",	cmd_test,	0 },

  		{ "inject",	cmd_inject,	0 },

  	};

  	unsigned int i;

  	static const char ext[] = STRIP_EXTENSION;
  
  	if (sizeof(ext) > 1) {
  		i = strlen(argv[0]) - strlen(ext);
  		if (i > 0 && !strcmp(argv[0] + i, ext)) {
  			char *argv0 = strdup(argv[0]);
  			argv[0] = cmd = argv0;
  			argv0[i] = '\0';
  		}
  	}
  
  	/* Turn "perf cmd --help" into "perf help cmd" */
  	if (argc > 1 && !strcmp(argv[1], "--help")) {
  		argv[1] = argv[0];
  		argv[0] = cmd = "help";
  	}
  
  	for (i = 0; i < ARRAY_SIZE(commands); i++) {
  		struct cmd_struct *p = commands+i;
  		if (strcmp(p->cmd, cmd))
  			continue;
  		exit(run_builtin(p, argc, argv));
  	}
  }
  
  static void execv_dashed_external(const char **argv)
  {
  	struct strbuf cmd = STRBUF_INIT;
  	const char *tmp;
  	int status;
  
  	strbuf_addf(&cmd, "perf-%s", argv[0]);
  
  	/*
  	 * argv[0] must be the perf command, but the argv array
  	 * belongs to the caller, and may be reused in
  	 * subsequent loop iterations. Save argv[0] and
  	 * restore it on error.
  	 */
  	tmp = argv[0];
  	argv[0] = cmd.buf;
  
  	/*
  	 * if we fail because the command is not found, it is
  	 * OK to return. Otherwise, we just pass along the status code.
  	 */
  	status = run_command_v_opt(argv, 0);
  	if (status != -ERR_RUN_COMMAND_EXEC) {
  		if (IS_RUN_COMMAND_ERR(status))
  			die("unable to run '%s'", argv[0]);
  		exit(-status);
  	}
  	errno = ENOENT; /* as if we called execvp */
  
  	argv[0] = tmp;
  
  	strbuf_release(&cmd);
  }
  
  static int run_argv(int *argcp, const char ***argv)
  {
  	int done_alias = 0;
  
  	while (1) {
  		/* See if it's an internal command */
  		handle_internal_command(*argcp, *argv);
  
  		/* .. then try the external ones */
  		execv_dashed_external(*argv);
  
  		/* It could be an alias -- this works around the insanity
  		 * of overriding "perf log" with "perf show" by having
  		 * alias.log = show
  		 */
  		if (done_alias || !handle_alias(argcp, argv))
  			break;
  		done_alias = 1;
  	}
  
  	return done_alias;
  }

  /* mini /proc/mounts parser: searching for "^blah /mount/point debugfs" */
  static void get_debugfs_mntpt(void)
  {

  	const char *path = debugfs_mount(NULL);

  	if (path)
  		strncpy(debugfs_mntpt, path, sizeof(debugfs_mntpt));
  	else
  		debugfs_mntpt[0] = '\0';

  }

  
  int main(int argc, const char **argv)
  {
  	const char *cmd;
  
  	cmd = perf_extract_argv0_path(argv[0]);
  	if (!cmd)
  		cmd = "perf-help";

  	/* get debugfs mount point from /proc/mounts */
  	get_debugfs_mntpt();

  	/*
  	 * "perf-xxxx" is the same as "perf xxxx", but we obviously:
  	 *
  	 *  - cannot take flags in between the "perf" and the "xxxx".
  	 *  - cannot execute it externally (since it would just do
  	 *    the same thing over again)
  	 *
  	 * So we just directly call the internal command handler, and
  	 * die if that one cannot handle it.
  	 */
  	if (!prefixcmp(cmd, "perf-")) {

  		cmd += 5;

  		argv[0] = cmd;
  		handle_internal_command(argc, argv);
  		die("cannot handle %s internally", cmd);
  	}
  
  	/* Look for flags.. */
  	argv++;
  	argc--;
  	handle_options(&argv, &argc, NULL);
  	commit_pager_choice();

  	set_debugfs_path();

  	set_buildid_dir();

  	if (argc > 0) {
  		if (!prefixcmp(argv[0], "--"))
  			argv[0] += 2;
  	} else {
  		/* The user didn't specify a command; give them help */

  		printf("
   usage: %s
  
  ", perf_usage_string);

  		list_common_cmds_help();

  		printf("
   %s
  
  ", perf_more_info_string);

  		exit(1);
  	}
  	cmd = argv[0];
  
  	/*
  	 * We use PATH to find perf commands, but we prepend some higher

  	 * precedence paths: the "--exec-path" option, the PERF_EXEC_PATH

  	 * environment, and the $(perfexecdir) from the Makefile at build
  	 * time.
  	 */
  	setup_path();
  
  	while (1) {

  		static int done_help;
  		static int was_alias;

  		was_alias = run_argv(&argc, &argv);
  		if (errno != ENOENT)
  			break;

  		if (was_alias) {
  			fprintf(stderr, "Expansion of alias '%s' failed; "
  				"'%s' is not a perf-command
  ",
  				cmd, argv[0]);
  			exit(1);
  		}
  		if (!done_help) {
  			cmd = argv[0] = help_unknown_cmd(cmd);
  			done_help = 1;
  		} else
  			break;
  	}
  
  	fprintf(stderr, "Failed to run command '%s': %s
  ",
  		cmd, strerror(errno));
  
  	return 1;
  }