// This is an open source non-commercial project. Dear PVS-Studio, please check
// it. PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com

#define EXTERN
#include <assert.h>
#include <msgpack.h>
#include <stdbool.h>
#include <stdint.h>
#include <string.h>

#include "nvim/ascii.h"
#include "nvim/autocmd.h"
#include "nvim/buffer.h"
#include "nvim/channel.h"
#include "nvim/charset.h"
#include "nvim/decoration.h"
#include "nvim/decoration_provider.h"
#include "nvim/diff.h"
#include "nvim/eval.h"
#include "nvim/ex_cmds.h"
#include "nvim/ex_cmds2.h"
#include "nvim/ex_docmd.h"
#include "nvim/ex_getln.h"
#include "nvim/fileio.h"
#include "nvim/fold.h"
#include "nvim/getchar.h"
#include "nvim/hashtab.h"
#include "nvim/highlight.h"
#include "nvim/highlight_group.h"
#include "nvim/iconv.h"
#include "nvim/if_cscope.h"
#include "nvim/lua/executor.h"
#include "nvim/main.h"
#include "nvim/ui_client.h"
#include "nvim/vim.h"
#ifdef HAVE_LOCALE_H
# include <locale.h>
#endif
#include "nvim/garray.h"
#include "nvim/log.h"
#include "nvim/mark.h"
#include "nvim/mbyte.h"
#include "nvim/memline.h"
#include "nvim/memory.h"
#include "nvim/message.h"
#include "nvim/mouse.h"
#include "nvim/move.h"
#include "nvim/normal.h"
#include "nvim/ops.h"
#include "nvim/option.h"
#include "nvim/os/fileio.h"
#include "nvim/os/input.h"
#include "nvim/os/os.h"
#include "nvim/os/os_defs.h"
#include "nvim/os/time.h"
#include "nvim/os_unix.h"
#include "nvim/path.h"
#include "nvim/popupmnu.h"
#include "nvim/profile.h"
#include "nvim/quickfix.h"
#include "nvim/screen.h"
#include "nvim/shada.h"
#include "nvim/sign.h"
#include "nvim/state.h"
#include "nvim/strings.h"
#include "nvim/syntax.h"
#include "nvim/ui.h"
#include "nvim/ui_compositor.h"
#include "nvim/version.h"
#include "nvim/window.h"
#ifdef WIN32
# include "nvim/os/os_win_console.h"
#endif
#include "nvim/api/private/defs.h"
#include "nvim/api/private/dispatch.h"
#include "nvim/api/private/helpers.h"
#include "nvim/api/ui.h"
#include "nvim/event/loop.h"
#include "nvim/event/process.h"
#include "nvim/msgpack_rpc/channel.h"
#include "nvim/msgpack_rpc/helpers.h"
#include "nvim/msgpack_rpc/server.h"
#include "nvim/os/signal.h"
#ifndef WIN32
# include "nvim/os/pty_process_unix.h"
#endif
#include "nvim/api/extmark.h"

// values for "window_layout"
#define WIN_HOR     1       // "-o" horizontally split windows
#define WIN_VER     2       // "-O" vertically split windows
#define WIN_TABS    3       // "-p" windows on tab pages

// Values for edit_type.
#define EDIT_NONE   0       // no edit type yet
#define EDIT_FILE   1       // file name argument[s] given, use argument list
#define EDIT_STDIN  2       // read file from stdin
#define EDIT_TAG    3       // tag name argument given, use tagname
#define EDIT_QF     4       // start in quickfix mode

#ifdef INCLUDE_GENERATED_DECLARATIONS
# include "main.c.generated.h"
#endif

Loop main_loop;

static char *argv0 = NULL;

// Error messages
static const char *err_arg_missing = N_("Argument missing after");
static const char *err_opt_garbage = N_("Garbage after option argument");
static const char *err_opt_unknown = N_("Unknown option argument");
static const char *err_too_many_args = N_("Too many edit arguments");
static const char *err_extra_cmd =
  N_("Too many \"+command\", \"-c command\" or \"--cmd command\" arguments");

void event_init(void)
{
  loop_init(&main_loop, NULL);
  resize_events = multiqueue_new_child(main_loop.events);

  // early msgpack-rpc initialization
  msgpack_rpc_init_method_table();
  msgpack_rpc_helpers_init();
  input_init();
  signal_init();
  // finish mspgack-rpc initialization
  channel_init();
  terminal_init();
  ui_init();
}

/// @returns false if main_loop could not be closed gracefully
bool event_teardown(void)
{
  if (!main_loop.events) {
    input_stop();
    return true;
  }

  multiqueue_process_events(main_loop.events);
  loop_poll_events(&main_loop, 0);  // Drain thread_events, fast_events.
  input_stop();
  channel_teardown();
  process_teardown(&main_loop);
  timer_teardown();
  server_teardown();
  signal_teardown();
  terminal_teardown();

  return loop_close(&main_loop, true);
}

/// Performs early initialization.
///
/// Needed for unit tests. Must be called after `time_init()`.
void early_init(mparm_T *paramp)
{
  env_init();
  cmdline_init();
  eval_init();          // init global variables
  init_path(argv0 ? argv0 : "nvim");
  init_normal_cmds();   // Init the table of Normal mode commands.
  runtime_init();
  highlight_init();

#ifdef WIN32
  OSVERSIONINFO ovi;
  ovi.dwOSVersionInfoSize = sizeof(ovi);
  GetVersionEx(&ovi);
  snprintf(windowsVersion, sizeof(windowsVersion), "%d.%d",
           (int)ovi.dwMajorVersion, (int)ovi.dwMinorVersion);
#endif

#if defined(HAVE_LOCALE_H)
  // Setup to use the current locale (for ctype() and many other things).
  // NOTE: Translated messages with encodings other than latin1 will not
  // work until set_init_1() has been called!
  init_locale();
#endif

  // Allocate the first window and buffer.
  // Can't do anything without it, exit when it fails.
  if (!win_alloc_first()) {
    os_exit(0);
  }

  init_yank();                  // init yank buffers

  alist_init(&global_alist);    // Init the argument list to empty.
  global_alist.id = 0;

  // Set the default values for the options.
  // First find out the home directory, needed to expand "~" in options.
  init_homedir();               // find real value of $HOME
  set_init_1(paramp != NULL ? paramp->clean : false);
  log_init();
  TIME_MSG("inits 1");

  set_lang_var();               // set v:lang and v:ctype

  init_signs();
  ui_comp_syn_init();
}

#ifdef MAKE_LIB
int nvim_main(int argc, char **argv);  // silence -Wmissing-prototypes
int nvim_main(int argc, char **argv)
#elif defined(WIN32)
int wmain(int argc, wchar_t **argv_w)  // multibyte args on Windows. #7060
#else
int main(int argc, char **argv)
#endif
{
#if defined(WIN32) && !defined(MAKE_LIB)
  char **argv = xmalloc((size_t)argc * sizeof(char *));
  for (int i = 0; i < argc; i++) {
    char *buf = NULL;
    utf16_to_utf8(argv_w[i], -1, &buf);
    assert(buf);
    argv[i] = buf;
  }
#endif

  argv0 = argv[0];

  char_u *fname = NULL;   // file name from command line
  mparm_T params;         // various parameters passed between
                          // main() and other functions.
  char_u *cwd = NULL;     // current working dir on startup
  time_init();

  // Many variables are in `params` so that we can pass them around easily.
  // `argc` and `argv` are also copied, so that they can be changed.
  init_params(&params, argc, argv);

  // Since os_open is called during the init_startuptime, we need to call
  // fs_init before it.
  fs_init();

  init_startuptime(&params);

  // Need to find "--clean" before actually parsing arguments.
  for (int i = 1; i < params.argc; i++) {
    if (STRICMP(params.argv[i], "--clean") == 0) {
      params.clean = true;
      break;
    }
  }

  event_init();

  early_init(&params);

  set_argv_var(argv, argc);  // set v:argv

  // Check if we have an interactive window.
  check_and_set_isatty(&params);

  // Process the command line arguments.  File names are put in the global
  // argument list "global_alist".
  command_line_scan(&params);

  nlua_init();

  if (embedded_mode) {
    const char *err;
    if (!channel_from_stdio(true, CALLBACK_READER_INIT, &err)) {
      abort();
    }
  }

  server_init(params.listen_addr);
  if (params.remote) {
    remote_request(&params, params.remote, params.server_addr, argc, argv);
  }

  if (GARGCOUNT > 0) {
    fname = get_fname(&params, cwd);
  }

  // Recovery mode without a file name: List swap files.
  // In this case, no UI is needed.
  if (recoverymode && fname == NULL) {
    headless_mode = true;
  }

  TIME_MSG("expanding arguments");

  if (params.diff_mode && params.window_count == -1) {
    params.window_count = 0;            // open up to 3 windows
  }
  // Don't redraw until much later.
  RedrawingDisabled++;

  setbuf(stdout, NULL);

  full_screen = !silent_mode;

  // Set the default values for the options that use Rows and Columns.
  win_init_size();
  // Set the 'diff' option now, so that it can be checked for in a vimrc
  // file.  There is no buffer yet though.
  if (params.diff_mode) {
    diff_win_options(firstwin, false);
  }

  assert(p_ch >= 0 && Rows >= p_ch && Rows - p_ch <= INT_MAX);
  cmdline_row = (int)(Rows - p_ch);
  msg_row = cmdline_row;
  screenalloc();  // allocate screen buffers
  set_init_2(headless_mode);
  TIME_MSG("inits 2");

  msg_scroll = true;
  no_wait_return = true;

  init_highlight(true, false);  // Default highlight groups.
  TIME_MSG("init highlight");

  // Set the break level after the terminal is initialized.
  debug_break_level = params.use_debug_break_level;

  // Read ex-commands if invoked with "-es".
  if (!params.input_isatty && !params.input_neverscript
      && silent_mode && exmode_active) {
    input_start(STDIN_FILENO);
  }

  // Wait for UIs to set up Nvim or show early messages
  // and prompts (--cmd, swapfile dialog, …).
  bool use_remote_ui = (embedded_mode && !headless_mode);
  bool use_builtin_ui = (!headless_mode && !embedded_mode && !silent_mode);
  if (use_remote_ui || use_builtin_ui) {
    TIME_MSG("waiting for UI");
    if (use_remote_ui) {
      remote_ui_wait_for_attach();
    } else {
      ui_builtin_start();
    }
    TIME_MSG("done waiting for UI");

    // prepare screen now, so external UIs can display messages
    starting = NO_BUFFERS;
    screenclear();
    TIME_MSG("init screen for UI");
  }

  if (ui_client_channel_id) {
    ui_client_init(ui_client_channel_id);
    ui_client_execute(ui_client_channel_id);
    abort();  // unreachable
  }

  init_default_mappings();  // Default mappings.
  TIME_MSG("init default mappings");

  init_default_autocmds();
  TIME_MSG("init default autocommands");

  bool vimrc_none = params.use_vimrc != NULL && strequal(params.use_vimrc, "NONE");

  // Reset 'loadplugins' for "-u NONE" before "--cmd" arguments.
  // Allows for setting 'loadplugins' there.
  if (vimrc_none) {
    // When using --clean we still want to load plugins
    p_lpl = params.clean;
  }

  // Execute --cmd arguments.
  exe_pre_commands(&params);

  if (!vimrc_none || params.clean) {
    // Sources ftplugin.vim and indent.vim. We do this *before* the user startup scripts to ensure
    // ftplugins run before FileType autocommands defined in the init file (which allows those
    // autocommands to overwrite settings from ftplugins).
    filetype_plugin_enable();
  }

  // Source startup scripts.
  source_startup_scripts(&params);

  // If using the runtime (-u is not NONE), enable syntax & filetype plugins.
  if (!vimrc_none || params.clean) {
    // Sources filetype.lua and filetype.vim unless the user explicitly disabled it with :filetype
    // off.
    filetype_maybe_enable();
    // Sources syntax/syntax.vim. We do this *after* the user startup scripts so that users can
    // disable syntax highlighting with `:syntax off` if they wish.
    syn_maybe_enable();
  }

  // Read all the plugin files.
  load_plugins();

  // Decide about window layout for diff mode after reading vimrc.
  set_window_layout(&params);

  // Recovery mode without a file name: List swap files.
  // Uses the 'dir' option, therefore it must be after the initializations.
  if (recoverymode && fname == NULL) {
    recover_names(NULL, true, 0, NULL);
    os_exit(0);
  }

  // Set some option defaults after reading vimrc files.
  set_init_3();
  TIME_MSG("inits 3");

  // "-n" argument: Disable swap file by setting 'updatecount' to 0.
  // Note that this overrides anything from a vimrc file.
  if (params.no_swap_file) {
    p_uc = 0;
  }

  // XXX: Minimize 'updatetime' for -es/-Es. #7679
  if (silent_mode) {
    p_ut = 1;
  }

  //
  // Read in registers, history etc, from the ShaDa file.
  // This is where v:oldfiles gets filled.
  //
  if (*p_shada != NUL) {
    shada_read_everything(NULL, false, true);
    TIME_MSG("reading ShaDa");
  }
  // It's better to make v:oldfiles an empty list than NULL.
  if (get_vim_var_list(VV_OLDFILES) == NULL) {
    set_vim_var_list(VV_OLDFILES, tv_list_alloc(0));
  }

  // "-q errorfile": Load the error file now.
  // If the error file can't be read, exit before doing anything else.
  handle_quickfix(&params);

  //
  // Start putting things on the screen.
  // Scroll screen down before drawing over it
  // Clear screen now, so file message will not be cleared.
  //
  starting = NO_BUFFERS;
  no_wait_return = false;
  if (!exmode_active) {
    msg_scroll = false;
  }

  // Read file (text, not commands) from stdin if:
  //    - stdin is not a tty
  //    - and -e/-es was not given
  //
  // Do this before starting Raw mode, because it may change things that the
  // writing end of the pipe doesn't like, e.g., in case stdin and stderr
  // are the same terminal: "cat | vim -".
  // Using autocommands here may cause trouble...
  if (params.edit_type == EDIT_STDIN && !recoverymode) {
    read_stdin();
  }

  setmouse();  // may start using the mouse

  if (exmode_active || use_remote_ui || use_builtin_ui) {
    // Don't clear the screen when starting in Ex mode, or when a UI might have
    // displayed messages.
    redraw_later(curwin, VALID);
  } else {
    screenclear();  // clear screen
    TIME_MSG("clearing screen");
  }

  no_wait_return = true;

  //
  // Create the requested number of windows and edit buffers in them.
  // Also does recovery if "recoverymode" set.
  //
  create_windows(&params);
  TIME_MSG("opening buffers");

  // Clear v:swapcommand
  set_vim_var_string(VV_SWAPCOMMAND, NULL, -1);

  // Ex starts at last line of the file.
  if (exmode_active) {
    curwin->w_cursor.lnum = curbuf->b_ml.ml_line_count;
  }

  apply_autocmds(EVENT_BUFENTER, NULL, NULL, false, curbuf);
  TIME_MSG("BufEnter autocommands");
  setpcmark();

  // When started with "-q errorfile" jump to first error now.
  if (params.edit_type == EDIT_QF) {
    qf_jump(NULL, 0, 0, FALSE);
    TIME_MSG("jump to first error");
  }

  // If opened more than one window, start editing files in the other
  // windows.
  edit_buffers(&params, cwd);
  xfree(cwd);

  if (params.diff_mode) {
    // set options in each window for "nvim -d".
    FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
      diff_win_options(wp, TRUE);
    }
  }

  // Shorten any of the filenames, but only when absolute.
  shorten_fnames(false);

  // Need to jump to the tag before executing the '-c command'.
  // Makes "vim -c '/return' -t main" work.
  handle_tag(params.tagname);

  // Execute any "+", "-c" and "-S" arguments.
  if (params.n_commands > 0) {
    exe_commands(&params);
  }

  starting = 0;

  RedrawingDisabled = 0;
  redraw_all_later(NOT_VALID);
  no_wait_return = false;

  // 'autochdir' has been postponed.
  do_autochdir();

  // start in insert mode
  if (p_im) {
    need_start_insertmode = true;
  }

  set_vim_var_nr(VV_VIM_DID_ENTER, 1L);
  apply_autocmds(EVENT_VIMENTER, NULL, NULL, false, curbuf);
  TIME_MSG("VimEnter autocommands");
  if (use_remote_ui || use_builtin_ui) {
    do_autocmd_uienter(use_remote_ui ? CHAN_STDIO : 0, true);
    TIME_MSG("UIEnter autocommands");
  }

  // Adjust default register name for "unnamed" in 'clipboard'. Can only be
  // done after the clipboard is available and all initial commands that may
  // modify the 'clipboard' setting have run; i.e. just before entering the
  // main loop.
  set_reg_var(get_default_register_name());

  // When a startup script or session file setup for diff'ing and
  // scrollbind, sync the scrollbind now.
  if (curwin->w_p_diff && curwin->w_p_scb) {
    update_topline(curwin);
    check_scrollbind((linenr_T)0, 0L);
    TIME_MSG("diff scrollbinding");
  }

  // If ":startinsert" command used, stuff a dummy command to be able to
  // call normal_cmd(), which will then start Insert mode.
  if (restart_edit != 0) {
    stuffcharReadbuff(K_NOP);
  }

  // WORKAROUND(mhi): #3023
  if (cb_flags & CB_UNNAMEDMASK) {
    (void)eval_has_provider("clipboard");
  }

  TIME_MSG("before starting main loop");
  ILOG("starting main loop");

  // Main loop: never returns.
  normal_enter(false, false);

#if defined(WIN32) && !defined(MAKE_LIB)
  xfree(argv);
#endif
  return 0;
}

void os_exit(int r)
  FUNC_ATTR_NORETURN
{
  exiting = true;

  ui_flush();
  ui_call_stop();
  ml_close_all(true);           // remove all memfiles

  if (!event_teardown() && r == 0) {
    r = 1;  // Exit with error if main_loop did not teardown gracefully.
  }
  if (input_global_fd() >= 0) {
    stream_set_blocking(input_global_fd(), true);  // normalize stream (#2598)
  }

  ILOG("Nvim exit: %d", r);

#ifdef EXITFREE
  free_all_mem();
#endif

  exit(r);
}

/// Exit properly
void getout(int exitval)
  FUNC_ATTR_NORETURN
{
  exiting = true;

  // When running in Ex mode an error causes us to exit with a non-zero exit
  // code.  POSIX requires this, although it's not 100% clear from the
  // standard.
  if (exmode_active) {
    exitval += ex_exitval;
  }

  set_vim_var_nr(VV_EXITING, exitval);

  // Position the cursor on the last screen line, below all the text
  ui_cursor_goto(Rows - 1, 0);

  // Optionally print hashtable efficiency.
  hash_debug_results();

  if (v_dying <= 1) {
    const tabpage_T *next_tp;

    // Trigger BufWinLeave for all windows, but only once per buffer.
    for (const tabpage_T *tp = first_tabpage; tp != NULL; tp = next_tp) {
      next_tp = tp->tp_next;
      FOR_ALL_WINDOWS_IN_TAB(wp, tp) {
        if (wp->w_buffer == NULL) {
          // Autocmd must have close the buffer already, skip.
          continue;
        }

        buf_T *buf = wp->w_buffer;
        if (buf_get_changedtick(buf) != -1) {
          bufref_T bufref;

          set_bufref(&bufref, buf);
          apply_autocmds(EVENT_BUFWINLEAVE, buf->b_fname,
                         buf->b_fname, false, buf);
          if (bufref_valid(&bufref)) {
            buf_set_changedtick(buf, -1);  // note that we did it already
          }
          // start all over, autocommands may mess up the lists
          next_tp = first_tabpage;
          break;
        }
      }
    }

    // Trigger BufUnload for buffers that are loaded
    FOR_ALL_BUFFERS(buf) {
      if (buf->b_ml.ml_mfp != NULL) {
        bufref_T bufref;
        set_bufref(&bufref, buf);
        apply_autocmds(EVENT_BUFUNLOAD, buf->b_fname, buf->b_fname, false, buf);
        if (!bufref_valid(&bufref)) {
          // Autocmd deleted the buffer.
          break;
        }
      }
    }

    int unblock = 0;
    // deathtrap() blocks autocommands, but we do want to trigger
    // VimLeavePre.
    if (is_autocmd_blocked()) {
      unblock_autocmds();
      unblock++;
    }
    apply_autocmds(EVENT_VIMLEAVEPRE, NULL, NULL, false, curbuf);
    if (unblock) {
      block_autocmds();
    }
  }

  if (p_shada && *p_shada != NUL) {
    // Write out the registers, history, marks etc, to the ShaDa file
    shada_write_file(NULL, false);
  }

  if (v_dying <= 1) {
    int unblock = 0;

    // deathtrap() blocks autocommands, but we do want to trigger VimLeave.
    if (is_autocmd_blocked()) {
      unblock_autocmds();
      unblock++;
    }
    apply_autocmds(EVENT_VIMLEAVE, NULL, NULL, false, curbuf);
    if (unblock) {
      block_autocmds();
    }
  }

  profile_dump();

  if (did_emsg) {
    // give the user a chance to read the (error) message
    no_wait_return = FALSE;
    wait_return(FALSE);
  }

  // Position the cursor again, the autocommands may have moved it
  ui_cursor_goto(Rows - 1, 0);

  // Apply 'titleold'.
  if (p_title && *p_titleold != NUL) {
    ui_call_set_title(cstr_as_string((char *)p_titleold));
  }

  cs_end();
  if (garbage_collect_at_exit) {
    garbage_collect(false);
  }

  os_exit(exitval);
}

/// Preserve files and exit.
/// @note IObuff must contain a message.
/// @note This may be called from deadly_signal() in a signal handler, avoid
///       unsafe functions, such as allocating memory.
void preserve_exit(void)
  FUNC_ATTR_NORETURN
{
  // 'true' when we are sure to exit, e.g., after a deadly signal
  static bool really_exiting = false;

  // Prevent repeated calls into this method.
  if (really_exiting) {
    if (input_global_fd() >= 0) {
      // normalize stream (#2598)
      stream_set_blocking(input_global_fd(), true);
    }
    exit(2);
  }

  really_exiting = true;
  // Ignore SIGHUP while we are already exiting. #9274
  signal_reject_deadly();
  mch_errmsg(IObuff);
  mch_errmsg("\n");
  ui_flush();

  ml_close_notmod();                // close all not-modified buffers

  FOR_ALL_BUFFERS(buf) {
    if (buf->b_ml.ml_mfp != NULL && buf->b_ml.ml_mfp->mf_fname != NULL) {
      mch_errmsg("Vim: preserving files...\r\n");
      ui_flush();
      ml_sync_all(false, false, true);  // preserve all swap files
      break;
    }
  }

  ml_close_all(false);              // close all memfiles, without deleting

  mch_errmsg("Vim: Finished.\r\n");

  getout(1);
}

/// Gets the integer value of a numeric command line argument if given,
/// such as '-o10'.
///
/// @param[in] p         pointer to argument
/// @param[in, out] idx  pointer to index in argument, is incremented
/// @param[in] def       default value
///
/// @return def unmodified if:
///   - argument isn't given
///   - argument is non-numeric
///
/// @return argument's numeric value otherwise
static int get_number_arg(const char *p, int *idx, int def)
  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT
{
  if (ascii_isdigit(p[*idx])) {  // -V522
    def = atoi(&(p[*idx]));
    while (ascii_isdigit(p[*idx])) {
      *idx = *idx + 1;
    }
  }
  return def;
}

#if defined(HAVE_LOCALE_H)
/// Setup to use the current locale (for ctype() and many other things).
static void init_locale(void)
{
  setlocale(LC_ALL, "");

# ifdef LC_NUMERIC
  // Make sure strtod() uses a decimal point, not a comma.
  setlocale(LC_NUMERIC, "C");
# endif

  char localepath[MAXPATHL] = { 0 };
  snprintf(localepath, sizeof(localepath), "%s", get_vim_var_str(VV_PROGPATH));
  char *tail = (char *)path_tail_with_sep((char_u *)localepath);
  *tail = NUL;
  tail = (char *)path_tail((char_u *)localepath);
  xstrlcpy(tail, "share/locale",
           sizeof(localepath) - (size_t)(tail - localepath));
  bindtextdomain(PROJECT_NAME, localepath);
  textdomain(PROJECT_NAME);
  TIME_MSG("locale set");
}
#endif


static uint64_t server_connect(char *server_addr, const char **errmsg)
{
  if (server_addr == NULL) {
    *errmsg = "no address specified";
    return 0;
  }
  CallbackReader on_data = CALLBACK_READER_INIT;
  const char *error = NULL;
  bool is_tcp = strrchr(server_addr, ':') ? true : false;
  // connected to channel
  uint64_t chan = channel_connect(is_tcp, server_addr, true, on_data, 50, &error);
  if (error) {
    *errmsg = error;
    return 0;
  }
  return chan;
}

/// Handle remote subcommands
static void remote_request(mparm_T *params, int remote_args,
                           char *server_addr, int argc, char **argv)
{
  const char *connect_error = NULL;
  uint64_t chan = server_connect(server_addr, &connect_error);
  Object rvobj = OBJECT_INIT;

  if (strequal(argv[remote_args], "--remote-ui-test")) {
    if (!chan) {
      emsg(connect_error);
      exit(1);
    }

    ui_client_channel_id = chan;
    return;
  }

  Array args = ARRAY_DICT_INIT;
  String arg_s;
  for (int t_argc = remote_args; t_argc < argc; t_argc++) {
    arg_s = cstr_to_string(argv[t_argc]);
    ADD(args, STRING_OBJ(arg_s));
  }

  Error err = ERROR_INIT;
  Array a = ARRAY_DICT_INIT;
  ADD(a, INTEGER_OBJ((int)chan));
  ADD(a, CSTR_TO_OBJ(server_addr));
  ADD(a, CSTR_TO_OBJ(connect_error));
  ADD(a, ARRAY_OBJ(args));
  String s = STATIC_CSTR_AS_STRING("return vim._cs_remote(...)");
  Object o = nlua_exec(s, a, &err);
  api_free_array(a);
  if (ERROR_SET(&err)) {
    mch_errmsg(err.msg);
    mch_errmsg("\n");
    os_exit(2);
  }

  if (o.type == kObjectTypeDictionary) {
    rvobj.data.dictionary = o.data.dictionary;
  } else {
    mch_errmsg("vim._cs_remote returned unexpected value\n");
    os_exit(2);
  }

  TriState should_exit = kNone;
  TriState tabbed = kNone;

  for (size_t i = 0; i < rvobj.data.dictionary.size ; i++) {
    if (strcmp(rvobj.data.dictionary.items[i].key.data, "errmsg") == 0) {
      if (rvobj.data.dictionary.items[i].value.type != kObjectTypeString) {
        mch_errmsg("vim._cs_remote returned an unexpected type for 'errmsg'\n");
        os_exit(2);
      }
      mch_errmsg(rvobj.data.dictionary.items[i].value.data.string.data);
      mch_errmsg("\n");
      os_exit(2);
    } else if (strcmp(rvobj.data.dictionary.items[i].key.data, "tabbed") == 0) {
      if (rvobj.data.dictionary.items[i].value.type != kObjectTypeBoolean) {
        mch_errmsg("vim._cs_remote returned an unexpected type for 'tabbed'\n");
        os_exit(2);
      }
      tabbed = rvobj.data.dictionary.items[i].value.data.boolean ? kTrue : kFalse;
    } else if (strcmp(rvobj.data.dictionary.items[i].key.data, "should_exit") == 0) {
      if (rvobj.data.dictionary.items[i].value.type != kObjectTypeBoolean) {
        mch_errmsg("vim._cs_remote returned an unexpected type for 'should_exit'\n");
        os_exit(2);
      }
      should_exit = rvobj.data.dictionary.items[i].value.data.boolean ? kTrue : kFalse;
    }
  }
  if (should_exit == kNone || tabbed == kNone) {
    mch_errmsg("vim._cs_remote didn't return a value for should_exit or tabbed, bailing\n");
    os_exit(2);
  }
  api_free_object(o);

  if (should_exit == kTrue) {
    os_exit(0);
  }
  if (tabbed == kTrue) {
    params->window_count = argc - remote_args - 1;
    params->window_layout = WIN_TABS;
  }
}


/// Decides whether text (as opposed to commands) will be read from stdin.
/// @see EDIT_STDIN
static bool edit_stdin(bool explicit, mparm_T *parmp)
{
  bool implicit = !headless_mode
                  && !embedded_mode
                  && (!exmode_active || parmp->input_neverscript)
                  && !parmp->input_isatty
                  && scriptin[0] == NULL;  // `-s -` was not given.
  return explicit || implicit;
}

/// Scan the command line arguments.
static void command_line_scan(mparm_T *parmp)
{
  int argc = parmp->argc;
  char **argv = parmp->argv;
  int argv_idx;                         // index in argv[n][]
  bool had_stdin_file = false;          // found explicit "-" argument
  bool had_minmin = false;              // found "--" argument
  int want_argument;                    // option argument with argument
  long n;

  argc--;
  argv++;
  argv_idx = 1;  // active option letter is argv[0][argv_idx]
  while (argc > 0) {
    // "+" or "+{number}" or "+/{pat}" or "+{command}" argument.
    if (argv[0][0] == '+' && !had_minmin) {
      if (parmp->n_commands >= MAX_ARG_CMDS) {
        mainerr(err_extra_cmd, NULL);
      }
      argv_idx = -1;  // skip to next argument
      if (argv[0][1] == NUL) {
        parmp->commands[parmp->n_commands++] = "$";
      } else {
        parmp->commands[parmp->n_commands++] = &(argv[0][1]);
      }

      // Optional argument.
    } else if (argv[0][0] == '-' && !had_minmin) {
      want_argument = false;
      char c = argv[0][argv_idx++];
      switch (c) {
      case NUL:    // "nvim -"  read from stdin
        if (exmode_active) {
          // "nvim -e -" silent mode
          silent_mode = true;
          parmp->no_swap_file = true;
        } else {
          if (parmp->edit_type != EDIT_NONE
              && parmp->edit_type != EDIT_FILE
              && parmp->edit_type != EDIT_STDIN) {
            mainerr(err_too_many_args, argv[0]);
          }
          had_stdin_file = true;
          parmp->edit_type = EDIT_STDIN;
        }
        argv_idx = -1;  // skip to next argument
        break;
      case '-':    // "--" don't take any more option arguments
        // "--help" give help message
        // "--version" give version message
        // "--noplugin[s]" skip plugins
        // "--cmd <cmd>" execute cmd before vimrc
        // "--remote" execute commands remotey on a server
        // "--server" name of vim server to send remote commands to
        if (STRICMP(argv[0] + argv_idx, "help") == 0) {
          usage();
          os_exit(0);
        } else if (STRICMP(argv[0] + argv_idx, "version") == 0) {
          version();
          os_exit(0);
        } else if (STRICMP(argv[0] + argv_idx, "api-info") == 0) {
          FileDescriptor fp;
          const int fof_ret = file_open_fd(&fp, STDOUT_FILENO,
                                           kFileWriteOnly);
          msgpack_packer *p = msgpack_packer_new(&fp, msgpack_file_write);

          if (fof_ret != 0) {
            semsg(_("E5421: Failed to open stdin: %s"), os_strerror(fof_ret));
          }

          if (p == NULL) {
            emsg(_(e_outofmem));
          }

          Object md = DICTIONARY_OBJ(api_metadata());
          msgpack_rpc_from_object(md, p);

          msgpack_packer_free(p);
          const int ff_ret = file_flush(&fp);
          if (ff_ret < 0) {
            msgpack_file_write_error(ff_ret);
          }
          os_exit(0);
        } else if (STRICMP(argv[0] + argv_idx, "headless") == 0) {
          headless_mode = true;
        } else if (STRICMP(argv[0] + argv_idx, "embed") == 0) {
          embedded_mode = true;
        } else if (STRNICMP(argv[0] + argv_idx, "listen", 6) == 0) {
          want_argument = true;
          argv_idx += 6;
        } else if (STRNICMP(argv[0] + argv_idx, "literal", 7) == 0) {
          // Do nothing: file args are always literal. #7679
        } else if (STRNICMP(argv[0] + argv_idx, "remote", 6) == 0) {
          parmp->remote = parmp->argc - argc;
        } else if (STRNICMP(argv[0] + argv_idx, "server", 6) == 0) {
          want_argument = true;
          argv_idx += 6;
        } else if (STRNICMP(argv[0] + argv_idx, "noplugin", 8) == 0) {
          p_lpl = false;
        } else if (STRNICMP(argv[0] + argv_idx, "cmd", 3) == 0) {
          want_argument = true;
          argv_idx += 3;
        } else if (STRNICMP(argv[0] + argv_idx, "startuptime", 11) == 0) {
          want_argument = true;
          argv_idx += 11;
        } else if (STRNICMP(argv[0] + argv_idx, "clean", 5) == 0) {
          parmp->use_vimrc = "NONE";
          parmp->clean = true;
          set_option_value("shadafile", 0L, "NONE", 0);
        } else if (STRNICMP(argv[0] + argv_idx, "luamod-dev", 9) == 0) {
          nlua_disable_preload = true;
        } else {
          if (argv[0][argv_idx]) {
            mainerr(err_opt_unknown, argv[0]);
          }
          had_minmin = true;
        }
        if (!want_argument) {
          argv_idx = -1;  // skip to next argument
        }
        break;
      case 'A':    // "-A" start in Arabic mode.
        set_option_value("arabic", 1L, NULL, 0);
        break;
      case 'b':    // "-b" binary mode.
        // Needs to be effective before expanding file names, because
        // for Win32 this makes us edit a shortcut file itself,
        // instead of the file it links to.
        set_options_bin(curbuf->b_p_bin, 1, 0);
        curbuf->b_p_bin = 1;  // Binary file I/O.
        break;

      case 'D':    // "-D" Debugging
        parmp->use_debug_break_level = 9999;
        break;
      case 'd':    // "-d" 'diff'
        parmp->diff_mode = true;
        break;
      case 'e':    // "-e" Ex mode
        exmode_active = true;
        break;
      case 'E':    // "-E" Ex mode
        exmode_active = true;
        parmp->input_neverscript = true;
        break;
      case 'f':    // "-f"  GUI: run in foreground.
        break;
      case '?':    // "-?" give help message (for MS-Windows)
      case 'h':    // "-h" give help message
        usage();
        os_exit(0);
      case 'H':    // "-H" start in Hebrew mode: rl + hkmap set.
        p_hkmap = true;
        set_option_value("rl", 1L, NULL, 0);
        break;
      case 'l':    // "-l" lisp mode, 'lisp' and 'showmatch' on.
        set_option_value("lisp", 1L, NULL, 0);
        p_sm = true;
        break;
      case 'M':    // "-M"  no changes or writing of files
        reset_modifiable();
        FALLTHROUGH;
      case 'm':    // "-m"  no writing of files
        p_write = false;
        break;

      case 'N':    // "-N"  Nocompatible
      case 'X':    // "-X"  Do not connect to X server
        // No-op
        break;

      case 'n':    // "-n" no swap file
        parmp->no_swap_file = true;
        break;
      case 'p':    // "-p[N]" open N tab pages
        // default is 0: open window for each file
        parmp->window_count = get_number_arg(argv[0], &argv_idx, 0);
        parmp->window_layout = WIN_TABS;
        break;
      case 'o':    // "-o[N]" open N horizontal split windows
        // default is 0: open window for each file
        parmp->window_count = get_number_arg(argv[0], &argv_idx, 0);
        parmp->window_layout = WIN_HOR;
        break;
      case 'O':    // "-O[N]" open N vertical split windows
        // default is 0: open window for each file
        parmp->window_count = get_number_arg(argv[0], &argv_idx, 0);
        parmp->window_layout = WIN_VER;
        break;
      case 'q':    // "-q" QuickFix mode
        if (parmp->edit_type != EDIT_NONE) {
          mainerr(err_too_many_args, argv[0]);
        }
        parmp->edit_type = EDIT_QF;
        if (argv[0][argv_idx]) {  // "-q{errorfile}"
          parmp->use_ef = (char_u *)argv[0] + argv_idx;
          argv_idx = -1;
        } else if (argc > 1) {    // "-q {errorfile}"
          want_argument = true;
        }
        break;
      case 'R':    // "-R" readonly mode
        readonlymode = true;
        curbuf->b_p_ro = true;
        p_uc = 10000;  // don't update very often
        break;
      case 'r':    // "-r" recovery mode
      case 'L':    // "-L" recovery mode
        recoverymode = 1;
        break;
      case 's':
        if (exmode_active) {    // "-es" silent (batch) Ex-mode
          silent_mode = true;
          parmp->no_swap_file = true;
        } else {                // "-s {scriptin}" read from script file
          want_argument = true;
        }
        break;
      case 't':    // "-t {tag}" or "-t{tag}" jump to tag
        if (parmp->edit_type != EDIT_NONE) {
          mainerr(err_too_many_args, argv[0]);
        }
        parmp->edit_type = EDIT_TAG;
        if (argv[0][argv_idx]) {  // "-t{tag}"
          parmp->tagname = (char_u *)argv[0] + argv_idx;
          argv_idx = -1;
        } else {  // "-t {tag}"
          want_argument = true;
        }
        break;
      case 'v':
        version();
        os_exit(0);
      case 'V':    // "-V{N}" Verbose level
        // default is 10: a little bit verbose
        p_verbose = get_number_arg(argv[0], &argv_idx, 10);
        if (argv[0][argv_idx] != NUL) {
          set_option_value("verbosefile", 0L, argv[0] + argv_idx, 0);
          argv_idx = (int)STRLEN(argv[0]);
        }
        break;
      case 'w':    // "-w{number}" set window height
        // "-w {scriptout}" write to script
        if (ascii_isdigit(((char_u *)argv[0])[argv_idx])) {
          n = get_number_arg(argv[0], &argv_idx, 10);
          set_option_value("window", n, NULL, 0);
          break;
        }
        want_argument = true;
        break;

      case 'c':    // "-c{command}" or "-c {command}" exec command
        if (argv[0][argv_idx] != NUL) {
          if (parmp->n_commands >= MAX_ARG_CMDS) {
            mainerr(err_extra_cmd, NULL);
          }
          parmp->commands[parmp->n_commands++] = argv[0] + argv_idx;
          argv_idx = -1;
          break;
        }
        FALLTHROUGH;
      case 'S':    // "-S {file}" execute Vim script
      case 'i':    // "-i {shada}" use for ShaDa file
      case 'u':    // "-u {vimrc}" vim inits file
      case 'U':    // "-U {gvimrc}" gvim inits file
      case 'W':    // "-W {scriptout}" overwrite
        want_argument = true;
        break;

      default:
        mainerr(err_opt_unknown, argv[0]);
      }

      // Handle option arguments with argument.
      if (want_argument) {
        // Check for garbage immediately after the option letter.
        if (argv[0][argv_idx] != NUL) {
          mainerr(err_opt_garbage, argv[0]);
        }

        argc--;
        if (argc < 1 && c != 'S') {  // -S has an optional argument
          mainerr(err_arg_missing, argv[0]);
        }
        argv++;
        argv_idx = -1;

        switch (c) {
        case 'c':    // "-c {command}" execute command
        case 'S':    // "-S {file}" execute Vim script
          if (parmp->n_commands >= MAX_ARG_CMDS) {
            mainerr(err_extra_cmd, NULL);
          }
          if (c == 'S') {
            char *a;

            if (argc < 1) {
              // "-S" without argument: use default session file name.
              a = SESSION_FILE;
            } else if (argv[0][0] == '-') {
              // "-S" followed by another option: use default session file.
              a = SESSION_FILE;
              ++argc;
              --argv;
            } else {
              a = argv[0];
            }

            size_t s_size = STRLEN(a) + 9;
            char *s = xmalloc(s_size);
            snprintf(s, s_size, "so %s", a);
            parmp->cmds_tofree[parmp->n_commands] = true;
            parmp->commands[parmp->n_commands++] = s;
          } else {
            parmp->commands[parmp->n_commands++] = argv[0];
          }
          break;

        case '-':
          if (strequal(argv[-1], "--cmd")) {
            // "--cmd {command}" execute command
            if (parmp->n_pre_commands >= MAX_ARG_CMDS) {
              mainerr(err_extra_cmd, NULL);
            }
            parmp->pre_commands[parmp->n_pre_commands++] = argv[0];
          } else if (strequal(argv[-1], "--listen")) {
            // "--listen {address}"
            parmp->listen_addr = argv[0];
          } else if (strequal(argv[-1], "--server")) {
            // "--server {address}"
            parmp->server_addr = argv[0];
          }
          // "--startuptime <file>" already handled
          break;

        case 'q':    // "-q {errorfile}" QuickFix mode
          parmp->use_ef = (char_u *)argv[0];
          break;

        case 'i':    // "-i {shada}" use for shada
          set_option_value("shadafile", 0L, argv[0], 0);
          break;

        case 's': {  // "-s {scriptin}" read from script file
          if (scriptin[0] != NULL) {
scripterror:
            vim_snprintf((char *)IObuff, IOSIZE,
                         _("Attempt to open script file again: \"%s %s\"\n"),
                         argv[-1], argv[0]);
            mch_errmsg((const char *)IObuff);
            os_exit(2);
          }
          int error;
          if (strequal(argv[0], "-")) {
            const int stdin_dup_fd = os_dup(STDIN_FILENO);
#ifdef WIN32
            // Replace the original stdin with the console input handle.
            os_replace_stdin_to_conin();
#endif
            FileDescriptor *const stdin_dup = file_open_fd_new(&error, stdin_dup_fd,
                                                               kFileReadOnly|kFileNonBlocking);
            assert(stdin_dup != NULL);
            scriptin[0] = stdin_dup;
          } else if ((scriptin[0] =
                        file_open_new(&error, argv[0], kFileReadOnly|kFileNonBlocking,
                                      0)) == NULL) {
            vim_snprintf((char *)IObuff, IOSIZE,
                         _("Cannot open for reading: \"%s\": %s\n"),
                         argv[0], os_strerror(error));
            mch_errmsg((const char *)IObuff);
            os_exit(2);
          }
          save_typebuf();
          break;
        }

        case 't':    // "-t {tag}"
          parmp->tagname = (char_u *)argv[0];
          break;
        case 'u':    // "-u {vimrc}" vim inits file
          parmp->use_vimrc = argv[0];
          break;
        case 'U':    // "-U {gvimrc}" gvim inits file
          break;

        case 'w':    // "-w {nr}" 'window' value
          // "-w {scriptout}" append to script file
          if (ascii_isdigit(*((char_u *)argv[0]))) {
            argv_idx = 0;
            n = get_number_arg(argv[0], &argv_idx, 10);
            set_option_value("window", n, NULL, 0);
            argv_idx = -1;
            break;
          }
          FALLTHROUGH;
        case 'W':    // "-W {scriptout}" overwrite script file
          if (scriptout != NULL) {
            goto scripterror;
          }
          if ((scriptout = os_fopen(argv[0], c == 'w' ? APPENDBIN : WRITEBIN))
              == NULL) {
            mch_errmsg(_("Cannot open for script output: \""));
            mch_errmsg(argv[0]);
            mch_errmsg("\"\n");
            os_exit(2);
          }
          break;
        }
      }
    } else {  // File name argument.
      argv_idx = -1;  // skip to next argument

      // Check for only one type of editing.
      if (parmp->edit_type != EDIT_NONE
          && parmp->edit_type != EDIT_FILE
          && parmp->edit_type != EDIT_STDIN) {
        mainerr(err_too_many_args, argv[0]);
      }
      parmp->edit_type = EDIT_FILE;

      // Add the file to the global argument list.
      ga_grow(&global_alist.al_ga, 1);
      char_u *p = vim_strsave((char_u *)argv[0]);

      if (parmp->diff_mode && os_isdir(p) && GARGCOUNT > 0
          && !os_isdir(alist_name(&GARGLIST[0]))) {
        char_u *r = (char_u *)concat_fnames((char *)p,
                                            (char *)path_tail(alist_name(&GARGLIST[0])), true);
        xfree(p);
        p = r;
      }

#ifdef USE_FNAME_CASE
      // Make the case of the file name match the actual file.
      path_fix_case(p);
#endif

      int alist_fnum_flag = edit_stdin(had_stdin_file, parmp)
                            ? 1   // add buffer nr after exp.
                            : 2;  // add buffer number now and use curbuf
      alist_add(&global_alist, p, alist_fnum_flag);
    }

    // If there are no more letters after the current "-", go to next argument.
    // argv_idx is set to -1 when the current argument is to be skipped.
    if (argv_idx <= 0 || argv[0][argv_idx] == NUL) {
      argc--;
      argv++;
      argv_idx = 1;
    }
  }

  if (embedded_mode && silent_mode) {
    mainerr(_("--embed conflicts with -es/-Es"), NULL);
  }

  // If there is a "+123" or "-c" command, set v:swapcommand to the first one.
  if (parmp->n_commands > 0) {
    const size_t swcmd_len = STRLEN(parmp->commands[0]) + 3;
    char *const swcmd = xmalloc(swcmd_len);
    snprintf(swcmd, swcmd_len, ":%s\r", parmp->commands[0]);
    set_vim_var_string(VV_SWAPCOMMAND, swcmd, -1);
    xfree(swcmd);
  }

  // Handle "foo | nvim". EDIT_FILE may be overwritten now. #6299
  if (edit_stdin(had_stdin_file, parmp)) {
    parmp->edit_type = EDIT_STDIN;
  }

  TIME_MSG("parsing arguments");
}

/*
 * Many variables are in "params" so that we can pass them to invoked
 * functions without a lot of arguments.  "argc" and "argv" are also
 * copied, so that they can be changed. */
static void init_params(mparm_T *paramp, int argc, char **argv)
{
  memset(paramp, 0, sizeof(*paramp));
  paramp->argc = argc;
  paramp->argv = argv;
  paramp->use_debug_break_level = -1;
  paramp->window_count = -1;
  paramp->listen_addr = NULL;
  paramp->server_addr = NULL;
  paramp->remote = 0;
}

/// Initialize global startuptime file if "--startuptime" passed as an argument.
static void init_startuptime(mparm_T *paramp)
{
  for (int i = 1; i < paramp->argc - 1; i++) {
    if (STRICMP(paramp->argv[i], "--startuptime") == 0) {
      time_fd = os_fopen(paramp->argv[i + 1], "a");
      time_start("--- NVIM STARTING ---");
      break;
    }
  }

  starttime = time(NULL);
}

static void check_and_set_isatty(mparm_T *paramp)
{
  stdin_isatty
    = paramp->input_isatty = os_isatty(STDIN_FILENO);
  stdout_isatty
    = paramp->output_isatty = os_isatty(STDOUT_FILENO);
  paramp->err_isatty = os_isatty(STDERR_FILENO);
#ifndef WIN32
  int tty_fd = paramp->input_isatty
    ? STDIN_FILENO
    : (paramp->output_isatty
       ? STDOUT_FILENO
       : (paramp->err_isatty ? STDERR_FILENO : -1));
  pty_process_save_termios(tty_fd);
#endif
  TIME_MSG("window checked");
}

// Sets v:progname and v:progpath. Also modifies $PATH on Windows.
static void init_path(const char *exename)
  FUNC_ATTR_NONNULL_ALL
{
  char exepath[MAXPATHL] = { 0 };
  size_t exepathlen = MAXPATHL;
  // Make v:progpath absolute.
  if (os_exepath(exepath, &exepathlen) != 0) {
    // Fall back to argv[0]. Missing procfs? #6734
    path_guess_exepath(exename, exepath, sizeof(exepath));
  }
  set_vim_var_string(VV_PROGPATH, exepath, -1);
  set_vim_var_string(VV_PROGNAME, (char *)path_tail((char_u *)exename), -1);

#ifdef WIN32
  // Append the process start directory to $PATH, so that ":!foo" finds tools
  // shipped with Windows package. This also mimics SearchPath().
  os_setenv_append_path(exepath);
#endif
}

/// Get filename from command line, if any.
static char_u *get_fname(mparm_T *parmp, char_u *cwd)
{
  return alist_name(&GARGLIST[0]);
}

/*
 * Decide about window layout for diff mode after reading vimrc.
 */
static void set_window_layout(mparm_T *paramp)
{
  if (paramp->diff_mode && paramp->window_layout == 0) {
    if (diffopt_horizontal()) {
      paramp->window_layout = WIN_HOR;             // use horizontal split
    } else {
      paramp->window_layout = WIN_VER;             // use vertical split
    }
  }
}


/*
 * "-q errorfile": Load the error file now.
 * If the error file can't be read, exit before doing anything else.
 */
static void handle_quickfix(mparm_T *paramp)
{
  if (paramp->edit_type == EDIT_QF) {
    if (paramp->use_ef != NULL) {
      set_string_option_direct("ef", -1, paramp->use_ef, OPT_FREE, SID_CARG);
    }
    vim_snprintf((char *)IObuff, IOSIZE, "cfile %s", p_ef);
    if (qf_init(NULL, p_ef, p_efm, true, IObuff, p_menc) < 0) {
      msg_putchar('\n');
      os_exit(3);
    }
    TIME_MSG("reading errorfile");
  }
}

/*
 * Need to jump to the tag before executing the '-c command'.
 * Makes "vim -c '/return' -t main" work.
 */
static void handle_tag(char_u *tagname)
{
  if (tagname != NULL) {
    swap_exists_did_quit = false;

    vim_snprintf((char *)IObuff, IOSIZE, "ta %s", tagname);
    do_cmdline_cmd((char *)IObuff);
    TIME_MSG("jumping to tag");

    // If the user doesn't want to edit the file then we quit here.
    if (swap_exists_did_quit) {
      getout(1);
    }
  }
}

/// Read text from stdin.
static void read_stdin(void)
{
  // When getting the ATTENTION prompt here, use a dialog.
  swap_exists_action = SEA_DIALOG;
  no_wait_return = true;
  bool save_msg_didany = msg_didany;
  set_buflisted(true);
  // Create memfile and read from stdin.
  (void)open_buffer(true, NULL, 0);
  if (buf_is_empty(curbuf) && curbuf->b_next != NULL) {
    // stdin was empty, go to buffer 2 (e.g. "echo file1 | xargs nvim"). #8561
    do_cmdline_cmd("silent! bnext");
    // Delete the empty stdin buffer.
    do_cmdline_cmd("bwipeout 1");
  }
  no_wait_return = false;
  msg_didany = save_msg_didany;
  TIME_MSG("reading stdin");
  check_swap_exists_action();
}

/*
 * Create the requested number of windows and edit buffers in them.
 * Also does recovery if "recoverymode" set.
 */
static void create_windows(mparm_T *parmp)
{
  int dorewind;
  int done = 0;

  /*
   * Create the number of windows that was requested.
   */
  if (parmp->window_count == -1) {      // was not set
    parmp->window_count = 1;
  }
  if (parmp->window_count == 0) {
    parmp->window_count = GARGCOUNT;
  }
  if (parmp->window_count > 1) {
    // Don't change the windows if there was a command in vimrc that
    // already split some windows
    if (parmp->window_layout == 0) {
      parmp->window_layout = WIN_HOR;
    }
    if (parmp->window_layout == WIN_TABS) {
      parmp->window_count = make_tabpages(parmp->window_count);
      TIME_MSG("making tab pages");
    } else if (firstwin->w_next == NULL) {
      parmp->window_count = make_windows(parmp->window_count,
                                         parmp->window_layout == WIN_VER);
      TIME_MSG("making windows");
    } else {
      parmp->window_count = win_count();
    }
  } else {
    parmp->window_count = 1;
  }

  if (recoverymode) {                   // do recover
    msg_scroll = true;                  // scroll message up
    ml_recover(true);
    if (curbuf->b_ml.ml_mfp == NULL) {   // failed
      getout(1);
    }
    do_modelines(0);                    // do modelines
  } else {
    // Open a buffer for windows that don't have one yet.
    // Commands in the vimrc might have loaded a file or split the window.
    // Watch out for autocommands that delete a window.
    //
    // Don't execute Win/Buf Enter/Leave autocommands here
    ++autocmd_no_enter;
    ++autocmd_no_leave;
    dorewind = TRUE;
    while (done++ < 1000) {
      if (dorewind) {
        if (parmp->window_layout == WIN_TABS) {
          goto_tabpage(1);
        } else {
          curwin = firstwin;
        }
      } else if (parmp->window_layout == WIN_TABS) {
        if (curtab->tp_next == NULL) {
          break;
        }
        goto_tabpage(0);
      } else {
        if (curwin->w_next == NULL) {
          break;
        }
        curwin = curwin->w_next;
      }
      dorewind = FALSE;
      curbuf = curwin->w_buffer;
      if (curbuf->b_ml.ml_mfp == NULL) {
        // Set 'foldlevel' to 'foldlevelstart' if it's not negative..
        if (p_fdls >= 0) {
          curwin->w_p_fdl = p_fdls;
        }
        // When getting the ATTENTION prompt here, use a dialog.
        swap_exists_action = SEA_DIALOG;
        set_buflisted(TRUE);

        // create memfile, read file
        (void)open_buffer(FALSE, NULL, 0);

        if (swap_exists_action == SEA_QUIT) {
          if (got_int || only_one_window()) {
            // abort selected or quit and only one window
            did_emsg = FALSE;               // avoid hit-enter prompt
            getout(1);
          }
          // We can't close the window, it would disturb what
          // happens next.  Clear the file name and set the arg
          // index to -1 to delete it later.
          setfname(curbuf, NULL, NULL, false);
          curwin->w_arg_idx = -1;
          swap_exists_action = SEA_NONE;
        } else {
          handle_swap_exists(NULL);
        }
        dorewind = TRUE;                        // start again
      }
      os_breakcheck();
      if (got_int) {
        (void)vgetc();          // only break the file loading, not the rest
        break;
      }
    }
    if (parmp->window_layout == WIN_TABS) {
      goto_tabpage(1);
    } else {
      curwin = firstwin;
    }
    curbuf = curwin->w_buffer;
    --autocmd_no_enter;
    --autocmd_no_leave;
  }
}

/// If opened more than one window, start editing files in the other
/// windows. make_windows() has already opened the windows.
static void edit_buffers(mparm_T *parmp, char_u *cwd)
{
  int arg_idx;                          // index in argument list
  int i;
  bool advance = true;
  win_T *win;
  char *p_shm_save = NULL;

  /*
   * Don't execute Win/Buf Enter/Leave autocommands here
   */
  ++autocmd_no_enter;
  ++autocmd_no_leave;

  // When w_arg_idx is -1 remove the window (see create_windows()).
  if (curwin->w_arg_idx == -1) {
    win_close(curwin, true, false);
    advance = false;
  }

  arg_idx = 1;
  for (i = 1; i < parmp->window_count; ++i) {
    if (cwd != NULL) {
      os_chdir((char *)cwd);
    }
    // When w_arg_idx is -1 remove the window (see create_windows()).
    if (curwin->w_arg_idx == -1) {
      arg_idx++;
      win_close(curwin, true, false);
      advance = false;
      continue;
    }

    if (advance) {
      if (parmp->window_layout == WIN_TABS) {
        if (curtab->tp_next == NULL) {          // just checking
          break;
        }
        goto_tabpage(0);
        // Temporarily reset 'shm' option to not print fileinfo when
        // loading the other buffers. This would overwrite the already
        // existing fileinfo for the first tab.
        if (i == 1) {
          char buf[100];

          p_shm_save = xstrdup((char *)p_shm);
          snprintf(buf, sizeof(buf), "F%s", p_shm);
          set_option_value("shm", 0L, buf, 0);
        }
      } else {
        if (curwin->w_next == NULL) {           // just checking
          break;
        }
        win_enter(curwin->w_next, false);
      }
    }
    advance = true;

    // Only open the file if there is no file in this window yet (that can
    // happen when vimrc contains ":sall").
    if (curbuf == firstwin->w_buffer || curbuf->b_ffname == NULL) {
      curwin->w_arg_idx = arg_idx;
      // Edit file from arg list, if there is one.  When "Quit" selected
      // at the ATTENTION prompt close the window.
      swap_exists_did_quit = false;
      (void)do_ecmd(0, arg_idx < GARGCOUNT
          ? alist_name(&GARGLIST[arg_idx]) : NULL,
                    NULL, NULL, ECMD_LASTL, ECMD_HIDE, curwin);
      if (swap_exists_did_quit) {
        // abort or quit selected
        if (got_int || only_one_window()) {
          // abort selected and only one window
          did_emsg = FALSE;             // avoid hit-enter prompt
          getout(1);
        }
        win_close(curwin, true, false);
        advance = false;
      }
      if (arg_idx == GARGCOUNT - 1) {
        arg_had_last = true;
      }
      arg_idx++;
    }
    os_breakcheck();
    if (got_int) {
      (void)vgetc();            // only break the file loading, not the rest
      break;
    }
  }

  if (p_shm_save != NULL) {
    set_option_value("shm", 0L, p_shm_save, 0);
    xfree(p_shm_save);
  }

  if (parmp->window_layout == WIN_TABS) {
    goto_tabpage(1);
  }
  --autocmd_no_enter;

  // make the first window the current window
  win = firstwin;
  // Avoid making a preview window the current window.
  while (win->w_p_pvw) {
    win = win->w_next;
    if (win == NULL) {
      win = firstwin;
      break;
    }
  }
  win_enter(win, false);

  --autocmd_no_leave;
  TIME_MSG("editing files in windows");
  if (parmp->window_count > 1 && parmp->window_layout != WIN_TABS) {
    win_equal(curwin, false, 'b');      // adjust heights
  }
}

/*
 * Execute the commands from --cmd arguments "cmds[cnt]".
 */
static void exe_pre_commands(mparm_T *parmp)
{
  char **cmds = parmp->pre_commands;
  int cnt = parmp->n_pre_commands;
  int i;

  if (cnt > 0) {
    curwin->w_cursor.lnum = 0;     // just in case..
    sourcing_name = (char_u *)_("pre-vimrc command line");
    current_sctx.sc_sid = SID_CMDARG;
    for (i = 0; i < cnt; i++) {
      do_cmdline_cmd(cmds[i]);
    }
    sourcing_name = NULL;
    current_sctx.sc_sid = 0;
    TIME_MSG("--cmd commands");
  }
}

/*
 * Execute "+", "-c" and "-S" arguments.
 */
static void exe_commands(mparm_T *parmp)
{
  int i;

  /*
   * We start commands on line 0, make "vim +/pat file" match a
   * pattern on line 1.  But don't move the cursor when an autocommand
   * with g`" was used.
   */
  msg_scroll = TRUE;
  if (parmp->tagname == NULL && curwin->w_cursor.lnum <= 1) {
    curwin->w_cursor.lnum = 0;
  }
  sourcing_name = (char_u *)"command line";
  current_sctx.sc_sid = SID_CARG;
  current_sctx.sc_seq = 0;
  for (i = 0; i < parmp->n_commands; i++) {
    do_cmdline_cmd(parmp->commands[i]);
    if (parmp->cmds_tofree[i]) {
      xfree(parmp->commands[i]);
    }
  }
  sourcing_name = NULL;
  current_sctx.sc_sid = 0;
  if (curwin->w_cursor.lnum == 0) {
    curwin->w_cursor.lnum = 1;
  }

  if (!exmode_active) {
    msg_scroll = FALSE;
  }

  // When started with "-q errorfile" jump to first error again.
  if (parmp->edit_type == EDIT_QF) {
    qf_jump(NULL, 0, 0, FALSE);
  }
  TIME_MSG("executing command arguments");
}

/// Source system-wide vimrc if built with one defined
///
/// Does one of the following things, stops after whichever succeeds:
///
/// 1. Source system vimrc file from $XDG_CONFIG_DIRS/nvim/sysinit.vim
/// 2. Source system vimrc file from $VIM
static void do_system_initialization(void)
{
  char *const config_dirs = stdpaths_get_xdg_var(kXDGConfigDirs);
  if (config_dirs != NULL) {
    const void *iter = NULL;
    const char path_tail[] = {
      'n', 'v', 'i', 'm', PATHSEP,
      's', 'y', 's', 'i', 'n', 'i', 't', '.', 'v', 'i', 'm', NUL
    };
    do {
      const char *dir;
      size_t dir_len;
      iter = vim_env_iter(':', config_dirs, iter, &dir, &dir_len);
      if (dir == NULL || dir_len == 0) {
        break;
      }
      char *vimrc = xmalloc(dir_len + sizeof(path_tail) + 1);
      memcpy(vimrc, dir, dir_len);
      if (vimrc[dir_len - 1] != PATHSEP) {
        vimrc[dir_len] = PATHSEP;
        dir_len += 1;
      }
      memcpy(vimrc + dir_len, path_tail, sizeof(path_tail));
      if (do_source(vimrc, false, DOSO_NONE) != FAIL) {
        xfree(vimrc);
        xfree(config_dirs);
        return;
      }
      xfree(vimrc);
    } while (iter != NULL);
    xfree(config_dirs);
  }

#ifdef SYS_VIMRC_FILE
  // Get system wide defaults, if the file name is defined.
  (void)do_source(SYS_VIMRC_FILE, false, DOSO_NONE);
#endif
}

/// Source vimrc or do other user initialization
///
/// Does one of the following things, stops after whichever succeeds:
///
/// 1. Execution of VIMINIT environment variable.
/// 2. Sourcing user vimrc file ($XDG_CONFIG_HOME/nvim/init.vim).
/// 3. Sourcing other vimrc files ($XDG_CONFIG_DIRS[1]/nvim/init.vim, …).
/// 4. Execution of EXINIT environment variable.
///
/// @return True if it is needed to attempt to source exrc file according to
///         'exrc' option definition.
static bool do_user_initialization(void)
  FUNC_ATTR_WARN_UNUSED_RESULT
{
  bool do_exrc = p_exrc;
  if (execute_env("VIMINIT") == OK) {
    do_exrc = p_exrc;
    return do_exrc;
  }

  char_u *init_lua_path = (char_u *)stdpaths_user_conf_subpath("init.lua");
  char_u *user_vimrc = (char_u *)stdpaths_user_conf_subpath("init.vim");

  // init.lua
  if (os_path_exists(init_lua_path)
      && do_source((char *)init_lua_path, true, DOSO_VIMRC)) {
    if (os_path_exists(user_vimrc)) {
      semsg(_("E5422: Conflicting configs: \"%s\" \"%s\""), init_lua_path,
            user_vimrc);
    }

    xfree(user_vimrc);
    xfree(init_lua_path);
    return false;
  }
  xfree(init_lua_path);

  // init.vim
  if (do_source((char *)user_vimrc, true, DOSO_VIMRC) != FAIL) {
    do_exrc = p_exrc;
    if (do_exrc) {
      do_exrc = (path_full_compare((char_u *)VIMRC_FILE, user_vimrc,
                                   false, true)
                 != kEqualFiles);
    }
    xfree(user_vimrc);
    return do_exrc;
  }
  xfree(user_vimrc);

  char *const config_dirs = stdpaths_get_xdg_var(kXDGConfigDirs);
  if (config_dirs != NULL) {
    const void *iter = NULL;
    do {
      const char *dir;
      size_t dir_len;
      iter = vim_env_iter(':', config_dirs, iter, &dir, &dir_len);
      if (dir == NULL || dir_len == 0) {
        break;
      }
      const char path_tail[] = { 'n', 'v', 'i', 'm', PATHSEP,
                                 'i', 'n', 'i', 't', '.', 'v', 'i', 'm', NUL };
      char *vimrc = xmalloc(dir_len + sizeof(path_tail) + 1);
      memmove(vimrc, dir, dir_len);
      vimrc[dir_len] = PATHSEP;
      memmove(vimrc + dir_len + 1, path_tail, sizeof(path_tail));
      if (do_source(vimrc, true, DOSO_VIMRC) != FAIL) {
        do_exrc = p_exrc;
        if (do_exrc) {
          do_exrc = (path_full_compare((char_u *)VIMRC_FILE, (char_u *)vimrc,
                                       false, true) != kEqualFiles);
        }
        xfree(vimrc);
        xfree(config_dirs);
        return do_exrc;
      }
      xfree(vimrc);
    } while (iter != NULL);
    xfree(config_dirs);
  }

  if (execute_env("EXINIT") == OK) {
    do_exrc = p_exrc;
    return do_exrc;
  }
  return do_exrc;
}

/// Source startup scripts
static void source_startup_scripts(const mparm_T *const parmp)
  FUNC_ATTR_NONNULL_ALL
{
  // If -u given, use only the initializations from that file and nothing else.
  if (parmp->use_vimrc != NULL) {
    if (strequal(parmp->use_vimrc, "NONE")
        || strequal(parmp->use_vimrc, "NORC")) {
      // Do nothing.
    } else {
      if (do_source(parmp->use_vimrc, false, DOSO_NONE) != OK) {
        semsg(_("E282: Cannot read from \"%s\""), parmp->use_vimrc);
      }
    }
  } else if (!silent_mode) {
    do_system_initialization();

    if (do_user_initialization()) {
      // Read initialization commands from ".vimrc" or ".exrc" in current
      // directory.  This is only done if the 'exrc' option is set.
      // Because of security reasons we disallow shell and write commands
      // now, except for unix if the file is owned by the user or 'secure'
      // option has been reset in environment of global "exrc" or "vimrc".
      // Only do this if VIMRC_FILE is not the same as vimrc file sourced in
      // do_user_initialization.
#if defined(UNIX)
      // If vimrc file is not owned by user, set 'secure' mode.
      if (!file_owned(VIMRC_FILE))
#endif
      secure = p_secure;

      if (do_source(VIMRC_FILE, true, DOSO_VIMRC) == FAIL) {
#if defined(UNIX)
        // if ".exrc" is not owned by user set 'secure' mode
        if (!file_owned(EXRC_FILE)) {
          secure = p_secure;
        } else {
          secure = 0;
        }
#endif
        (void)do_source(EXRC_FILE, false, DOSO_NONE);
      }
    }
    if (secure == 2) {
      need_wait_return = true;
    }
    secure = 0;
  }
  TIME_MSG("sourcing vimrc file(s)");
}

/// Get an environment variable, and execute it as Ex commands.
///
/// @param env         environment variable to execute
///
/// @return FAIL if the environment variable was not executed,
///         OK otherwise.
static int execute_env(char *env)
  FUNC_ATTR_NONNULL_ALL
{
  const char *initstr = os_getenv(env);
  if (initstr != NULL) {
    char_u *save_sourcing_name = sourcing_name;
    linenr_T save_sourcing_lnum = sourcing_lnum;
    sourcing_name = (char_u *)env;
    sourcing_lnum = 0;
    const sctx_T save_current_sctx = current_sctx;
    current_sctx.sc_sid = SID_ENV;
    current_sctx.sc_seq = 0;
    current_sctx.sc_lnum = 0;
    do_cmdline_cmd((char *)initstr);
    sourcing_name = save_sourcing_name;
    sourcing_lnum = save_sourcing_lnum;
    current_sctx = save_current_sctx;
    return OK;
  }
  return FAIL;
}

#ifdef UNIX
/// Checks if user owns file.
/// Use both uv_fs_stat() and uv_fs_lstat() through os_fileinfo() and
/// os_fileinfo_link() respectively for extra security.
static bool file_owned(const char *fname)
{
  assert(fname != NULL);
  uid_t uid = getuid();
  FileInfo file_info;
  bool file_owned = os_fileinfo(fname, &file_info)
                    && file_info.stat.st_uid == uid;
  bool link_owned = os_fileinfo_link(fname, &file_info)
                    && file_info.stat.st_uid == uid;
  return file_owned && link_owned;
}
#endif

/// Prints the following then exits:
/// - An error message `errstr`
/// - A string `str` if not null
///
/// @param errstr  string containing an error message
/// @param str     string to append to the primary error message, or NULL
static void mainerr(const char *errstr, const char *str)
  FUNC_ATTR_NORETURN
{
  char *prgname = (char *)path_tail((char_u *)argv0);

  signal_stop();              // kill us with CTRL-C here, if you like

  mch_errmsg(prgname);
  mch_errmsg(": ");
  mch_errmsg(_(errstr));
  if (str != NULL) {
    mch_errmsg(": \"");
    mch_errmsg(str);
    mch_errmsg("\"");
  }
  mch_errmsg(_("\nMore info with \""));
  mch_errmsg(prgname);
  mch_errmsg(" -h\"\n");

  os_exit(1);
}

/// Prints version information for "nvim -v" or "nvim --version".
static void version(void)
{
  // TODO(bfred): not like this?
  nlua_init();
  info_message = true;  // use mch_msg(), not mch_errmsg()
  list_version();
  msg_putchar('\n');
  msg_didout = false;
}

/// Prints help message for "nvim -h" or "nvim --help".
static void usage(void)
{
  signal_stop();              // kill us with CTRL-C here, if you like

  mch_msg(_("Usage:\n"));
  mch_msg(_("  nvim [options] [file ...]      Edit file(s)\n"));
  mch_msg(_("  nvim [options] -t <tag>        Edit file where tag is defined\n"));
  mch_msg(_("  nvim [options] -q [errorfile]  Edit file with first error\n"));
  mch_msg(_("\nOptions:\n"));
  mch_msg(_("  --                    Only file names after this\n"));
  mch_msg(_("  +                     Start at end of file\n"));
  mch_msg(_("  --cmd <cmd>           Execute <cmd> before any config\n"));
  mch_msg(_("  +<cmd>, -c <cmd>      Execute <cmd> after config and first file\n"));
  mch_msg("\n");
  mch_msg(_("  -b                    Binary mode\n"));
  mch_msg(_("  -d                    Diff mode\n"));
  mch_msg(_("  -e, -E                Ex mode\n"));
  mch_msg(_("  -es, -Es              Silent (batch) mode\n"));
  mch_msg(_("  -h, --help            Print this help message\n"));
  mch_msg(_("  -i <shada>            Use this shada file\n"));
  mch_msg(_("  -m                    Modifications (writing files) not allowed\n"));
  mch_msg(_("  -M                    Modifications in text not allowed\n"));
  mch_msg(_("  -n                    No swap file, use memory only\n"));
  mch_msg(_("  -o[N]                 Open N windows (default: one per file)\n"));
  mch_msg(_("  -O[N]                 Open N vertical windows (default: one per file)\n"));
  mch_msg(_("  -p[N]                 Open N tab pages (default: one per file)\n"));
  mch_msg(_("  -r, -L                List swap files\n"));
  mch_msg(_("  -r <file>             Recover edit state for this file\n"));
  mch_msg(_("  -R                    Read-only mode\n"));
  mch_msg(_("  -S <session>          Source <session> after loading the first file\n"));
  mch_msg(_("  -s <scriptin>         Read Normal mode commands from <scriptin>\n"));
  mch_msg(_("  -u <config>           Use this config file\n"));
  mch_msg(_("  -v, --version         Print version information\n"));
  mch_msg(_("  -V[N][file]           Verbose [level][file]\n"));
  mch_msg("\n");
  mch_msg(_("  --api-info            Write msgpack-encoded API metadata to stdout\n"));
  mch_msg(_("  --embed               Use stdin/stdout as a msgpack-rpc channel\n"));
  mch_msg(_("  --headless            Don't start a user interface\n"));
  mch_msg(_("  --listen <address>    Serve RPC API from this address\n"));
  mch_msg(_("  --noplugin            Don't load plugins\n"));
  mch_msg(_("  --remote[-subcommand] Execute commands remotely on a server\n"));
  mch_msg(_("  --server <address>    Specify RPC server to send commands to\n"));
  mch_msg(_("  --startuptime <file>  Write startup timing messages to <file>\n"));
  mch_msg(_("\nSee \":help startup-options\" for all options.\n"));
}


/*
 * Check the result of the ATTENTION dialog:
 * When "Quit" selected, exit Vim.
 * When "Recover" selected, recover the file.
 */
static void check_swap_exists_action(void)
{
  if (swap_exists_action == SEA_QUIT) {
    getout(1);
  }
  handle_swap_exists(NULL);
}
