/*
   * 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 "perf.h"

  #include "util/build-id.h"

  #include "util/cache.h"

  #include "util/env.h"

  #include <internal/lib.h> // page_size

  #include <subcmd/exec-cmd.h>

  #include "util/config.h"

  #include <subcmd/run-command.h>

  #include "util/parse-events.h"

  #include <subcmd/parse-options.h>

  #include "util/bpf-loader.h"

  #include "util/debug.h"

  #include "util/event.h"

  #include "util/util.h" // usage()

  #include "ui/ui.h"

  #include "perf-sys.h"

  #include <api/fs/fs.h>

  #include <api/fs/tracing_path.h>

  #include <perf/core.h>

  #include <errno.h>

  #include <pthread.h>

  #include <signal.h>

  #include <stdlib.h>
  #include <time.h>

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

  #include <linux/kernel.h>

  #include <linux/string.h>

  #include <linux/zalloc.h>

  
  const char perf_usage_string[] =

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

  
  const char perf_more_info_string[] =
  	"See 'perf help COMMAND' for more information on a specific command.";
  
  static int use_pager = -1;

  const char *input_name;

  struct cmd_struct {
  	const char *cmd;

  	int (*fn)(int, const char **);

  	int option;
  };
  
  static struct cmd_struct commands[] = {
  	{ "buildid-cache", cmd_buildid_cache, 0 },
  	{ "buildid-list", cmd_buildid_list, 0 },

  	{ "config",	cmd_config,	0 },

  	{ "c2c",	cmd_c2c,	0 },

  	{ "diff",	cmd_diff,	0 },
  	{ "evlist",	cmd_evlist,	0 },
  	{ "help",	cmd_help,	0 },

  	{ "kallsyms",	cmd_kallsyms,	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 },
  	{ "script",	cmd_script,	0 },
  	{ "sched",	cmd_sched,	0 },

  #ifdef HAVE_LIBELF_SUPPORT

  	{ "probe",	cmd_probe,	0 },

  #endif

  	{ "kmem",	cmd_kmem,	0 },
  	{ "lock",	cmd_lock,	0 },
  	{ "kvm",	cmd_kvm,	0 },
  	{ "test",	cmd_test,	0 },

  #if defined(HAVE_LIBAUDIT_SUPPORT) || defined(HAVE_SYSCALL_TABLE_SUPPORT)

  	{ "trace",	cmd_trace,	0 },

  #endif

  	{ "inject",	cmd_inject,	0 },

  	{ "mem",	cmd_mem,	0 },

  	{ "data",	cmd_data,	0 },

  	{ "ftrace",	cmd_ftrace,	0 },

  };

  struct pager_config {
  	const char *cmd;
  	int val;
  };
  
  static int pager_command_config(const char *var, const char *value, void *data)
  {
  	struct pager_config *c = data;

  	if (strstarts(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" */

  static int check_pager_config(const char *cmd)

  {

  	int err;

  	struct pager_config c;
  	c.cmd = cmd;
  	c.val = -1;

  	err = perf_config(pager_command_config, &c);
  	return err ?: c.val;

  }

  static int browser_command_config(const char *var, const char *value, void *data)

  {
  	struct pager_config *c = data;

  	if (strstarts(var, "tui.") && !strcmp(var + 4, c->cmd))

  		c->val = perf_config_bool(var, value);

  	if (strstarts(var, "gtk.") && !strcmp(var + 4, c->cmd))

  		c->val = perf_config_bool(var, value) ? 2 : 0;

  	return 0;
  }

  /*
   * returns 0 for "no tui", 1 for "use tui", 2 for "use gtk",
   * and -1 for "not specified"
   */
  static int check_browser_config(const char *cmd)

  {

  	int err;

  	struct pager_config c;
  	c.cmd = cmd;
  	c.val = -1;

  	err = perf_config(browser_command_config, &c);
  	return err ?: c.val;

  }

  static void commit_pager_choice(void)
  {

  	switch (use_pager) {
  	case 0:

  		setenv(PERF_PAGER_ENVIRONMENT, "cat", 1);

  		break;
  	case 1:
  		/* setup_pager(); */
  		break;
  	default:
  		break;
  	}
  }

  struct option options[] = {
  	OPT_ARGUMENT("help", "help"),
  	OPT_ARGUMENT("version", "version"),
  	OPT_ARGUMENT("exec-path", "exec-path"),
  	OPT_ARGUMENT("html-path", "html-path"),
  	OPT_ARGUMENT("paginate", "paginate"),
  	OPT_ARGUMENT("no-pager", "no-pager"),

  	OPT_ARGUMENT("debugfs-dir", "debugfs-dir"),
  	OPT_ARGUMENT("buildid-dir", "buildid-dir"),
  	OPT_ARGUMENT("list-cmds", "list-cmds"),
  	OPT_ARGUMENT("list-opts", "list-opts"),
  	OPT_ARGUMENT("debug", "debug"),
  	OPT_END()
  };

  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;
  
  		/*

  		 * Shortcut for '-h' and '-v' options to invoke help
  		 * and version command.
  		 */
  		if (!strcmp(cmd, "-h")) {
  			(*argv)[0] = "--help";
  			break;
  		}
  
  		if (!strcmp(cmd, "-v")) {
  			(*argv)[0] = "--version";
  			break;
  		}

  		if (!strcmp(cmd, "-vv")) {
  			(*argv)[0] = "version";
  			version_verbose = 1;
  			break;
  		}

  		/*

  		 * Check remaining flags.
  		 */

  		if (strstarts(cmd, CMD_EXEC_PATH)) {

  			cmd += strlen(CMD_EXEC_PATH);

  			if (*cmd == '=')

  				set_argv_exec_path(cmd + 1);

  			else {

  				puts(get_argv_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, "--debugfs-dir")) {
  			if (*argc < 2) {
  				fprintf(stderr, "No directory given for --debugfs-dir.
  ");
  				usage(perf_usage_string);
  			}

  			tracing_path_set((*argv)[1]);

  			if (envchanged)
  				*envchanged = 1;
  			(*argv)++;
  			(*argc)--;

  		} else if (!strcmp(cmd, "--buildid-dir")) {
  			if (*argc < 2) {
  				fprintf(stderr, "No directory given for --buildid-dir.
  ");
  				usage(perf_usage_string);
  			}
  			set_buildid_dir((*argv)[1]);
  			if (envchanged)
  				*envchanged = 1;
  			(*argv)++;
  			(*argc)--;

  		} else if (strstarts(cmd, CMD_DEBUGFS_DIR)) {

  			tracing_path_set(cmd + strlen(CMD_DEBUGFS_DIR));

  			fprintf(stderr, "dir: %s
  ", tracing_path_mount());

  			if (envchanged)
  				*envchanged = 1;

  		} else if (!strcmp(cmd, "--list-cmds")) {
  			unsigned int i;
  
  			for (i = 0; i < ARRAY_SIZE(commands); i++) {
  				struct cmd_struct *p = commands+i;
  				printf("%s ", p->cmd);
  			}

  			putchar('
  ');

  			exit(0);

  		} else if (!strcmp(cmd, "--list-opts")) {
  			unsigned int i;
  
  			for (i = 0; i < ARRAY_SIZE(options)-1; i++) {
  				struct option *p = options+i;
  				printf("--%s ", p->long_name);
  			}
  			putchar('
  ');
  			exit(0);

  		} else if (!strcmp(cmd, "--debug")) {
  			if (*argc < 2) {
  				fprintf(stderr, "No variable specified for --debug.
  ");
  				usage(perf_usage_string);
  			}
  			if (perf_debug_option((*argv)[1]))
  				usage(perf_usage_string);
  
  			(*argv)++;
  			(*argc)--;

  		} else {
  			fprintf(stderr, "Unknown option: %s
  ", cmd);
  			usage(perf_usage_string);
  		}
  
  		(*argv)++;
  		(*argc)--;
  		handled++;
  	}
  	return handled;
  }

  #define RUN_SETUP	(1<<0)
  #define USE_PAGER	(1<<1)

  static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
  {
  	int status;
  	struct stat st;

  	char sbuf[STRERR_BUFSIZE];

  	if (use_browser == -1)

  		use_browser = check_browser_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();

  	perf_env__init(&perf_env);

  	perf_env__set_cmdline(&perf_env, argc, argv);

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

  	perf_config__exit();

  	exit_browser(status);

  	perf_env__exit(&perf_env);

  	bpf__clear();

  	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;

  	status = 1;

  	/* Check for ENOSPC and EIO errors.. */

  	if (fflush(stdout)) {

  		fprintf(stderr, "write failure on standard output: %s",

  			str_error_r(errno, sbuf, sizeof(sbuf)));

  		goto out;
  	}
  	if (ferror(stdout)) {
  		fprintf(stderr, "unknown write failure on standard output");
  		goto out;
  	}
  	if (fclose(stdout)) {

  		fprintf(stderr, "close failed on standard output: %s",

  			str_error_r(errno, sbuf, sizeof(sbuf)));

  		goto out;
  	}
  	status = 0;
  out:
  	return status;

  }
  
  static void handle_internal_command(int argc, const char **argv)
  {
  	const char *cmd = argv[0];

  	unsigned int i;

  
  	/* 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)
  {

  	char *cmd;

  	const char *tmp;
  	int status;

  	if (asprintf(&cmd, "perf-%s", argv[0]) < 0)
  		goto do_die;

  
  	/*
  	 * 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;

  
  	/*
  	 * 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)) {
  do_die:

  			pr_err("FATAL: unable to run '%s'", argv[0]);
  			status = -128;

  		}

  		exit(-status);
  	}
  	errno = ENOENT; /* as if we called execvp */
  
  	argv[0] = tmp;

  	zfree(&cmd);

  }
  
  static int run_argv(int *argcp, const char ***argv)
  {

  	/* See if it's an internal command */
  	handle_internal_command(*argcp, *argv);

  	/* .. then try the external ones */
  	execv_dashed_external(*argv);
  	return 0;

  }

  static void pthread__block_sigwinch(void)
  {
  	sigset_t set;
  
  	sigemptyset(&set);
  	sigaddset(&set, SIGWINCH);
  	pthread_sigmask(SIG_BLOCK, &set, NULL);
  }
  
  void pthread__unblock_sigwinch(void)
  {
  	sigset_t set;
  
  	sigemptyset(&set);
  	sigaddset(&set, SIGWINCH);
  	pthread_sigmask(SIG_UNBLOCK, &set, NULL);
  }

  static int libperf_print(enum libperf_print_level level,
  			 const char *fmt, va_list ap)
  {
  	return eprintf(level, verbose, fmt, ap);
  }

  int main(int argc, const char **argv)
  {

  	int err;

  	const char *cmd;

  	char sbuf[STRERR_BUFSIZE];

  	/* libsubcmd init */
  	exec_cmd_init("perf", PREFIX, PERF_EXEC_PATH, EXEC_PATH_ENVIRONMENT);
  	pager_init(PERF_PAGER_ENVIRONMENT);

  	libperf_init(libperf_print);

  	cmd = extract_argv0_path(argv[0]);

  	if (!cmd)
  		cmd = "perf-help";

  	srandom(time(NULL));

  	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
  	config_exclusive_filename = getenv("PERF_CONFIG");

  	err = perf_config(perf_default_config, NULL);
  	if (err)
  		return err;

  	set_buildid_dir(NULL);

  	/*
  	 * "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. If that one
  	 * fails to handle this, then maybe we just run a renamed perf binary
  	 * that contains a dash in its name. To handle this scenario, we just
  	 * fall through and ignore the "xxxx" part of the command string.

  	 */

  	if (strstarts(cmd, "perf-")) {

  		cmd += 5;

  		argv[0] = cmd;
  		handle_internal_command(argc, argv);

  		/*
  		 * If the command is handled, the above function does not
  		 * return undo changes and fall through in such a case.
  		 */
  		cmd -= 5;
  		argv[0] = cmd;

  	}

  	if (strstarts(cmd, "trace")) {

  #if defined(HAVE_LIBAUDIT_SUPPORT) || defined(HAVE_SYSCALL_TABLE_SUPPORT)

  		setup_path();
  		argv[0] = "trace";

  		return cmd_trace(argc, argv);

  #else
  		fprintf(stderr,
  			"trace command not available: missing audit-libs devel package at build time.
  ");
  		goto out;

  #endif

  	}

  	/* Look for flags.. */
  	argv++;
  	argc--;
  	handle_options(&argv, &argc, NULL);
  	commit_pager_choice();

  	if (argc > 0) {

  		if (strstarts(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);

  		goto out;

  	}
  	cmd = argv[0];

  	test_attr__init();

  	/*
  	 * 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();

  	/*
  	 * Block SIGWINCH notifications so that the thread that wants it can
  	 * unblock and get syscalls like select interrupted instead of waiting
  	 * forever while the signal goes to some other non interested thread.
  	 */
  	pthread__block_sigwinch();

  	perf_debug_setup();

  	while (1) {

  		static int done_help;

  
  		run_argv(&argc, &argv);

  		if (errno != ENOENT)
  			break;

  		if (!done_help) {
  			cmd = argv[0] = help_unknown_cmd(cmd);
  			done_help = 1;
  		} else
  			break;
  	}
  
  	fprintf(stderr, "Failed to run command '%s': %s
  ",

  		cmd, str_error_r(errno, sbuf, sizeof(sbuf)));

  out:

  	return 1;
  }