pcomplete.c

/* pcomplete.c - functions to generate lists of matches for programmable completion. */

/* Copyright (C) 1999-2018 Free Software Foundation, Inc.

   This file is part of GNU Bash, the Bourne Again SHell.

   Bash is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   Bash is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <config.h>

#if defined (PROGRAMMABLE_COMPLETION)

#include "bashtypes.h"
#include "posixstat.h"

#if defined (HAVE_UNISTD_H)
#  include <unistd.h>
#endif

#include <signal.h>

#if defined (PREFER_STDARG)
#  include <stdarg.h>
#else
#  include <varargs.h>
#endif

#include <sys/time.h>

#include <stdio.h>
#include "bashansi.h"
#include "bashintl.h"

#include "shell.h"
#include "pcomplete.h"
#include "alias.h"
#include "bashline.h"
#include "execute_cmd.h"
#include "pathexp.h"

#if defined (JOB_CONTROL)
#  include "jobs.h"
#endif

#if !defined (NSIG)
#  include "trap.h"
#endif

#include "shmbutil.h"

#include "builtins.h"
#include "builtins/common.h"
#include "builtins/builtext.h"

#include <glob/glob.h>
#include <glob/strmatch.h>

#include <readline/rlconf.h>
#include <readline/readline.h>
#include <readline/history.h>

#ifdef STRDUP
#  undef STRDUP
#endif
#define STRDUP(x)	((x) ? savestring (x) : (char *)NULL)

typedef SHELL_VAR **SVFUNC ();

#ifndef HAVE_STRPBRK
extern char *strpbrk __P((char *, char *));
#endif

extern STRING_INT_ALIST word_token_alist[];
extern char *signal_names[];

#if defined (DEBUG)
#if defined (PREFER_STDARG)
static void debug_printf (const char *, ...)  __attribute__((__format__ (printf, 1, 2)));
#endif
#endif /* DEBUG */

static int it_init_joblist __P((ITEMLIST *, int));

static int it_init_aliases __P((ITEMLIST *));
static int it_init_arrayvars __P((ITEMLIST *));
static int it_init_bindings __P((ITEMLIST *));
static int it_init_builtins __P((ITEMLIST *));
static int it_init_disabled __P((ITEMLIST *));
static int it_init_enabled __P((ITEMLIST *));
static int it_init_exported __P((ITEMLIST *));
static int it_init_functions __P((ITEMLIST *));
static int it_init_helptopics __P((ITEMLIST *));
static int it_init_hostnames __P((ITEMLIST *));
static int it_init_jobs __P((ITEMLIST *));
static int it_init_running __P((ITEMLIST *));
static int it_init_stopped __P((ITEMLIST *));
static int it_init_keywords __P((ITEMLIST *));
static int it_init_signals __P((ITEMLIST *));
static int it_init_variables __P((ITEMLIST *));
static int it_init_setopts __P((ITEMLIST *));
static int it_init_shopts __P((ITEMLIST *));

static int shouldexp_filterpat __P((char *));
static char *preproc_filterpat __P((char *, const char *));

static void init_itemlist_from_varlist __P((ITEMLIST *, SVFUNC *));

static STRINGLIST *gen_matches_from_itemlist __P((ITEMLIST *, const char *));
static STRINGLIST *gen_action_completions __P((COMPSPEC *, const char *));
static STRINGLIST *gen_globpat_matches __P((COMPSPEC *, const char *));
static STRINGLIST *gen_wordlist_matches __P((COMPSPEC *, const char *));
static STRINGLIST *gen_shell_function_matches __P((COMPSPEC *, const char *,
						   const char *,
						   char *, int, WORD_LIST *,
						   int, int, int *));
static STRINGLIST *gen_command_matches __P((COMPSPEC *, const char *,
					    const char *,
					    char *, int, WORD_LIST *,
					    int, int));

static STRINGLIST *gen_progcomp_completions __P((const char *, const char *,
						 const char *,
						 int, int, int *, int *,
						 COMPSPEC **));

static char *pcomp_filename_completion_function __P((const char *, int));

#if defined (ARRAY_VARS)
static SHELL_VAR *bind_comp_words __P((WORD_LIST *));
#endif
static void bind_compfunc_variables __P((char *, int, WORD_LIST *, int, int));
static void unbind_compfunc_variables __P((int));
static WORD_LIST *build_arg_list __P((char *, const char *, const char *, WORD_LIST *, int));
static WORD_LIST *command_line_to_word_list __P((char *, int, int, int *, int *));

#ifdef DEBUG
static int progcomp_debug = 0;
#endif

int prog_completion_enabled = 1;

#ifdef ALIAS
int progcomp_alias = 0;	/* unavailable to user code for now */
#endif

/* These are used to manage the arrays of strings for possible completions. */
ITEMLIST it_aliases = { 0, it_init_aliases, (STRINGLIST *)0 };
ITEMLIST it_arrayvars  = { LIST_DYNAMIC, it_init_arrayvars, (STRINGLIST *)0 };
ITEMLIST it_bindings  = { 0, it_init_bindings, (STRINGLIST *)0 };
ITEMLIST it_builtins  = { 0, it_init_builtins, (STRINGLIST *)0 };
ITEMLIST it_commands = { LIST_DYNAMIC };	/* unused */
ITEMLIST it_directories = { LIST_DYNAMIC };	/* unused */
ITEMLIST it_disabled = { 0, it_init_disabled, (STRINGLIST *)0 };
ITEMLIST it_enabled = { 0, it_init_enabled, (STRINGLIST *)0 };
ITEMLIST it_exports  = { LIST_DYNAMIC, it_init_exported, (STRINGLIST *)0 };
ITEMLIST it_files = { LIST_DYNAMIC };		/* unused */
ITEMLIST it_functions  = { 0, it_init_functions, (STRINGLIST *)0 };
ITEMLIST it_helptopics  = { 0, it_init_helptopics, (STRINGLIST *)0 };
ITEMLIST it_hostnames  = { LIST_DYNAMIC, it_init_hostnames, (STRINGLIST *)0 };
ITEMLIST it_groups = { LIST_DYNAMIC };		/* unused */
ITEMLIST it_jobs = { LIST_DYNAMIC, it_init_jobs, (STRINGLIST *)0 };
ITEMLIST it_keywords = { 0, it_init_keywords, (STRINGLIST *)0 };
ITEMLIST it_running = { LIST_DYNAMIC, it_init_running, (STRINGLIST *)0 };
ITEMLIST it_services = { LIST_DYNAMIC };	/* unused */
ITEMLIST it_setopts = { 0, it_init_setopts, (STRINGLIST *)0 };
ITEMLIST it_shopts = { 0, it_init_shopts, (STRINGLIST *)0 };
ITEMLIST it_signals = { 0, it_init_signals, (STRINGLIST *)0 };
ITEMLIST it_stopped = { LIST_DYNAMIC, it_init_stopped, (STRINGLIST *)0 };
ITEMLIST it_users = { LIST_DYNAMIC };		/* unused */
ITEMLIST it_variables = { LIST_DYNAMIC, it_init_variables, (STRINGLIST *)0 };

COMPSPEC *pcomp_curcs;
const char *pcomp_curcmd;
const char *pcomp_curtxt;

char *pcomp_line;
int pcomp_ind;

#ifdef DEBUG
/* Debugging code */
static void
#if defined (PREFER_STDARG)
debug_printf (const char *format, ...)
#else
debug_printf (format, va_alist)
     const char *format;
     va_dcl
#endif
{
  va_list args;

  if (progcomp_debug == 0)
    return;

  SH_VA_START (args, format);

  fprintf (stdout, "DEBUG: ");
  vfprintf (stdout, format, args);
  fprintf (stdout, "\n");

  rl_on_new_line ();

  va_end (args);
}
#endif

/* Functions to manage the item lists */

void
set_itemlist_dirty (it)
     ITEMLIST *it;
{
  it->flags |= LIST_DIRTY;
}

void
initialize_itemlist (itp)
     ITEMLIST *itp;
{
  (*itp->list_getter) (itp);
  itp->flags |= LIST_INITIALIZED;
  itp->flags &= ~LIST_DIRTY;
}

void
clean_itemlist (itp)
     ITEMLIST *itp;
{
  STRINGLIST *sl;

  sl = itp->slist;
  if (sl)
    {
      if ((itp->flags & (LIST_DONTFREEMEMBERS|LIST_DONTFREE)) == 0)
	strvec_flush (sl->list);
      if ((itp->flags & LIST_DONTFREE) == 0)
	free (sl->list);
      free (sl);
    }
  itp->slist = (STRINGLIST *)NULL;
  itp->flags &= ~(LIST_DONTFREE|LIST_DONTFREEMEMBERS|LIST_INITIALIZED|LIST_DIRTY);
}


static int
shouldexp_filterpat (s)
     char *s;
{
  register char *p;

  for (p = s; p && *p; p++)
    {
      if (*p == '\\')
	p++;
      else if (*p == '&')
	return 1;
    }
  return 0;
}

/* Replace any instance of `&' in PAT with TEXT.  Backslash may be used to
   quote a `&' and inhibit substitution.  Returns a new string.  This just
   calls stringlib.c:strcreplace(). */
static char *
preproc_filterpat (pat, text)
     char *pat;
     const char *text;
{
  char *ret;

  ret = strcreplace (pat, '&', text, 1);
  return ret;
}
	
/* Remove any match of FILTERPAT from SL.  A `&' in FILTERPAT is replaced by
   TEXT.  A leading `!' in FILTERPAT negates the pattern; in this case
   any member of SL->list that does *not* match will be removed.  This returns
   a new STRINGLIST with the matching members of SL *copied*.  Any
   non-matching members of SL->list are *freed*. */   
STRINGLIST *
filter_stringlist (sl, filterpat, text)
     STRINGLIST *sl;
     char *filterpat;
     const char *text;
{
  int i, m, not;
  STRINGLIST *ret;
  char *npat, *t;

  if (sl == 0 || sl->list == 0 || sl->list_len == 0)
    return sl;

  npat = shouldexp_filterpat (filterpat) ? preproc_filterpat (filterpat, text) : filterpat;

#if defined (EXTENDED_GLOB)
  not = (npat[0] == '!' && (extended_glob == 0 || npat[1] != '('));	/*)*/
#else
  not = (npat[0] == '!');
#endif
  t = not ? npat + 1 : npat;

  ret = strlist_create (sl->list_size);
  for (i = 0; i < sl->list_len; i++)
    {
      m = strmatch (t, sl->list[i], FNMATCH_EXTFLAG | FNMATCH_IGNCASE);
      if ((not && m == FNM_NOMATCH) || (not == 0 && m != FNM_NOMATCH))
	free (sl->list[i]);
      else
	ret->list[ret->list_len++] = sl->list[i];
    }

  ret->list[ret->list_len] = (char *)NULL;
  if (npat != filterpat)
    free (npat);

  return ret;
}

/* Turn an array of strings returned by rl_completion_matches into a STRINGLIST.
   This understands how rl_completion_matches sets matches[0] (the lcd of the
   strings in the list, unless it's the only match). */
STRINGLIST *
completions_to_stringlist (matches)
     char **matches;
{
  STRINGLIST *sl;
  int mlen, i, n;

  mlen = (matches == 0) ? 0 : strvec_len (matches);
  sl = strlist_create (mlen + 1);

  if (matches == 0 || matches[0] == 0)
    return sl;

  if (matches[1] == 0)
    {
      sl->list[0] = STRDUP (matches[0]);
      sl->list[sl->list_len = 1] = (char *)NULL;
      return sl;
    }

  for (i = 1, n = 0; i < mlen; i++, n++)
    sl->list[n] = STRDUP (matches[i]);
  sl->list_len = n;
  sl->list[n] = (char *)NULL;

  return sl;
}

/* Functions to manage the various ITEMLISTs that we populate internally.
   The caller is responsible for setting ITP->flags correctly. */

static int
it_init_aliases (itp)
     ITEMLIST *itp;
{
#ifdef ALIAS
  alias_t **alias_list;
  register int i, n;
  STRINGLIST *sl;

  alias_list = all_aliases ();
  if (alias_list == 0)
    {
      itp->slist = (STRINGLIST *)NULL;
      return 0;
    }
  for (n = 0; alias_list[n]; n++)
    ;
  sl = strlist_create (n+1);
  for (i = 0; i < n; i++)
    sl->list[i] = STRDUP (alias_list[i]->name);
  sl->list[n] = (char *)NULL;
  sl->list_size = sl->list_len = n;
  itp->slist = sl;
#else
  itp->slist = (STRINGLIST *)NULL;
#endif
  free (alias_list);
  return 1;
}

static void
init_itemlist_from_varlist (itp, svfunc)
     ITEMLIST *itp;
     SVFUNC *svfunc;
{
  SHELL_VAR **vlist;
  STRINGLIST *sl;
  register int i, n;

  vlist = (*svfunc) ();
  if (vlist == 0)
    {
      itp->slist = (STRINGLIST *)NULL;
      return;
    }    
  for (n = 0; vlist[n]; n++)
    ;
  sl = strlist_create (n+1);
  for (i = 0; i < n; i++)
    sl->list[i] = savestring (vlist[i]->name);
  sl->list[sl->list_len = n] = (char *)NULL;
  itp->slist = sl;
}

static int
it_init_arrayvars (itp)
     ITEMLIST *itp;
{
#if defined (ARRAY_VARS)
  init_itemlist_from_varlist (itp, all_array_variables);
  return 1;
#else
  return 0;
#endif
}

static int
it_init_bindings (itp)
     ITEMLIST *itp;
{
  char **blist;
  STRINGLIST *sl;

  /* rl_funmap_names allocates blist, but not its members */
  blist = (char **)rl_funmap_names ();	/* XXX fix const later */
  sl = strlist_create (0);
  sl->list = blist;
  sl->list_size = 0;
  sl->list_len = strvec_len (sl->list);
  itp->flags |= LIST_DONTFREEMEMBERS;
  itp->slist = sl;

  return 0;
}

static int
it_init_builtins (itp)
     ITEMLIST *itp;
{
  STRINGLIST *sl;
  register int i, n;

  sl = strlist_create (num_shell_builtins);
  for (i = n = 0; i < num_shell_builtins; i++)
    if (shell_builtins[i].function)
      sl->list[n++] = shell_builtins[i].name;
  sl->list[sl->list_len = n] = (char *)NULL;
  itp->flags |= LIST_DONTFREEMEMBERS;
  itp->slist = sl;
  return 0;
}

static int
it_init_enabled (itp)
     ITEMLIST *itp;
{
  STRINGLIST *sl;
  register int i, n;

  sl = strlist_create (num_shell_builtins);
  for (i = n = 0; i < num_shell_builtins; i++)
    {
      if (shell_builtins[i].function && (shell_builtins[i].flags & BUILTIN_ENABLED))
	sl->list[n++] = shell_builtins[i].name;
    }
  sl->list[sl->list_len = n] = (char *)NULL;
  itp->flags |= LIST_DONTFREEMEMBERS;
  itp->slist = sl;
  return 0;
}

static int
it_init_disabled (itp)
     ITEMLIST *itp;
{
  STRINGLIST *sl;
  register int i, n;

  sl = strlist_create (num_shell_builtins);
  for (i = n = 0; i < num_shell_builtins; i++)
    {
      if (shell_builtins[i].function && ((shell_builtins[i].flags & BUILTIN_ENABLED) == 0))
	sl->list[n++] = shell_builtins[i].name;
    }
  sl->list[sl->list_len = n] = (char *)NULL;
  itp->flags |= LIST_DONTFREEMEMBERS;
  itp->slist = sl;
  return 0;
}

static int
it_init_exported (itp)
     ITEMLIST *itp;
{
  init_itemlist_from_varlist (itp, all_exported_variables);
  return 0;
}

static int
it_init_functions (itp)
     ITEMLIST *itp;
{
  init_itemlist_from_varlist (itp, all_visible_functions);
  return 0;
}

/* Like it_init_builtins, but includes everything the help builtin looks at,
   not just builtins with an active implementing function. */
static int
it_init_helptopics (itp)
     ITEMLIST *itp;
{
  STRINGLIST *sl;
  register int i, n;

  sl = strlist_create (num_shell_builtins);
  for (i = n = 0; i < num_shell_builtins; i++)
    sl->list[n++] = shell_builtins[i].name;
  sl->list[sl->list_len = n] = (char *)NULL;
  itp->flags |= LIST_DONTFREEMEMBERS;
  itp->slist = sl;
  return 0;
}

static int
it_init_hostnames (itp)
     ITEMLIST *itp;
{
  STRINGLIST *sl;

  sl = strlist_create (0);
  sl->list = get_hostname_list ();
  sl->list_len = sl->list ? strvec_len (sl->list) : 0;
  sl->list_size = sl->list_len;
  itp->slist = sl;
  itp->flags |= LIST_DONTFREEMEMBERS|LIST_DONTFREE;
  return 0;
}

static int
it_init_joblist (itp, jstate)
     ITEMLIST *itp;
     int jstate;
{
#if defined (JOB_CONTROL)
  STRINGLIST *sl;
  register int i;
  register PROCESS *p;
  char *s, *t;
  JOB *j;
  JOB_STATE ws;		/* wanted state */

  ws = JNONE;
  if (jstate == 0)
    ws = JRUNNING;
  else if (jstate == 1)
    ws = JSTOPPED;

  sl = strlist_create (js.j_jobslots);
  for (i = js.j_jobslots - 1; i >= 0; i--)
    {
      j = get_job_by_jid (i);
      if (j == 0)
	continue;
      p = j->pipe;
      if (jstate == -1 || JOBSTATE(i) == ws)
	{
	  s = savestring (p->command);
	  t = strpbrk (s, " \t\n");
	  if (t)
	    *t = '\0';
	  sl->list[sl->list_len++] = s;
	}
    }
  itp->slist = sl;
#else
  itp->slist = (STRINGLIST *)NULL;
#endif
  return 0;
}

static int
it_init_jobs (itp)
     ITEMLIST *itp;
{
  return (it_init_joblist (itp, -1));
}

static int
it_init_running (itp)
     ITEMLIST *itp;
{
  return (it_init_joblist (itp, 0));
}

static int
it_init_stopped (itp)
     ITEMLIST *itp;
{
  return (it_init_joblist (itp, 1));
}

static int
it_init_keywords (itp)
     ITEMLIST *itp;
{
  STRINGLIST *sl;
  register int i, n;

  for (n = 0; word_token_alist[n].word; n++)
    ;
  sl = strlist_create (n);
  for (i = 0; i < n; i++)
    sl->list[i] = word_token_alist[i].word;
  sl->list[sl->list_len = i] = (char *)NULL;
  itp->flags |= LIST_DONTFREEMEMBERS;
  itp->slist = sl;
  return 0;
}

static int
it_init_signals (itp)
     ITEMLIST *itp;
{
  STRINGLIST *sl;

  sl = strlist_create (0);
  sl->list = signal_names;
  sl->list_len = strvec_len (sl->list);
  itp->flags |= LIST_DONTFREE;
  itp->slist = sl;
  return 0;
}

static int
it_init_variables (itp)
     ITEMLIST *itp;
{
  init_itemlist_from_varlist (itp, all_visible_variables);
  return 0;
}

static int
it_init_setopts (itp)
     ITEMLIST *itp;
{
  STRINGLIST *sl;

  sl = strlist_create (0);
  sl->list = get_minus_o_opts ();
  sl->list_len = strvec_len (sl->list);
  itp->slist = sl;
  itp->flags |= LIST_DONTFREEMEMBERS;
  return 0;
}

static int
it_init_shopts (itp)
     ITEMLIST *itp;
{
  STRINGLIST *sl;

  sl = strlist_create (0);
  sl->list = get_shopt_options ();
  sl->list_len = strvec_len (sl->list);
  itp->slist = sl;
  itp->flags |= LIST_DONTFREEMEMBERS;
  return 0;
}

/* Generate a list of all matches for TEXT using the STRINGLIST in itp->slist
   as the list of possibilities.  If the itemlist has been marked dirty or
   it should be regenerated every time, destroy the old STRINGLIST and make a
   new one before trying the match.  TEXT is dequoted before attempting a
   match. */
static STRINGLIST *
gen_matches_from_itemlist (itp, text)
     ITEMLIST *itp;
     const char *text;
{
  STRINGLIST *ret, *sl;
  int tlen, i, n;
  char *ntxt;

  if ((itp->flags & (LIST_DIRTY|LIST_DYNAMIC)) ||
      (itp->flags & LIST_INITIALIZED) == 0)
    {
      if (itp->flags & (LIST_DIRTY|LIST_DYNAMIC))
	clean_itemlist (itp);
      if ((itp->flags & LIST_INITIALIZED) == 0)
	initialize_itemlist (itp);
    }
  if (itp->slist == 0)
    return ((STRINGLIST *)NULL);
  ret = strlist_create (itp->slist->list_len+1);
  sl = itp->slist;

  ntxt = bash_dequote_text (text);
  tlen = STRLEN (ntxt);

  for (i = n = 0; i < sl->list_len; i++)
    {
      if (tlen == 0 || STREQN (sl->list[i], ntxt, tlen))
	ret->list[n++] = STRDUP (sl->list[i]);
    }
  ret->list[ret->list_len = n] = (char *)NULL;

  FREE (ntxt);
  return ret;
}

/* A wrapper for rl_filename_completion_function that dequotes the filename
   before attempting completions. */
static char *
pcomp_filename_completion_function (text, state)
     const char *text;
     int state;
{
  static char *dfn;	/* dequoted filename */
  int iscompgen, iscompleting;

  if (state == 0)
    {
      FREE (dfn);
      /* remove backslashes quoting special characters in filenames. */
      /* There are roughly three paths we can follow to get here:
		1.  complete -f
		2.  compgen -f "$word" from a completion function
		3.  compgen -f "$word" from the command line
	 They all need to be handled.

	 In the first two cases, readline will run the filename dequoting
	 function in rl_filename_completion_function if it found a filename
	 quoting character in the word to be completed
	 (rl_completion_found_quote).  We run the dequoting function here
	 if we're running compgen, we're not completing, and the
	 rl_filename_completion_function won't dequote the filename
	 (rl_completion_found_quote == 0). */
      iscompgen = this_shell_builtin == compgen_builtin;
      iscompleting = RL_ISSTATE (RL_STATE_COMPLETING);
      if (iscompgen && iscompleting == 0 && rl_completion_found_quote == 0
	  && rl_filename_dequoting_function)
	{
	  /* Use rl_completion_quote_character because any single or
	     double quotes have been removed by the time TEXT makes it
	     here, and we don't want to remove backslashes inside
	     quoted strings. */
	  dfn = (*rl_filename_dequoting_function) ((char *)text, rl_completion_quote_character);
	}
      /* Intended to solve a mismatched assumption by bash-completion.  If
	 the text to be completed is empty, but bash-completion turns it into
	 a quoted string ('') assuming that this code will dequote it before
	 calling readline, do the dequoting. */
      else if (iscompgen && iscompleting &&
	       pcomp_curtxt && *pcomp_curtxt == 0 &&
	       text && (*text == '\'' || *text == '"') && text[1] == text[0] && text[2] == 0 && 
	       rl_filename_dequoting_function)
	dfn = (*rl_filename_dequoting_function) ((char *)text, rl_completion_quote_character);
      /* Another mismatched assumption by bash-completion.  If compgen is being
      	 run as part of bash-completion, and the argument to compgen is not
      	 the same as the word originally passed to the programmable completion
      	 code, dequote the argument if it has quote characters.  It's an
      	 attempt to detect when bash-completion is quoting its filename
      	 argument before calling compgen. */
      /* We could check whether gen_shell_function_matches is in the call
	 stack by checking whether the gen-shell-function-matches tag is in
	 the unwind-protect stack, but there's no function to do that yet.
	 We could simply check whether we're executing in a function by
	 checking variable_context, and may end up doing that. */
      else if (iscompgen && iscompleting && rl_filename_dequoting_function &&
	       pcomp_curtxt && text &&
	       STREQ (pcomp_curtxt, text) == 0 &&
	       variable_context &&
	       sh_contains_quotes (text))	/* guess */
	dfn = (*rl_filename_dequoting_function) ((char *)text, rl_completion_quote_character);
      else
	dfn = savestring (text);
    }

  return (rl_filename_completion_function (dfn, state));
}

#define GEN_COMPS(bmap, flag, it, text, glist, tlist) \
  do { \
    if (bmap & flag) \
      { \
	tlist = gen_matches_from_itemlist (it, text); \
	if (tlist) \
	  { \
	    glist = strlist_append (glist, tlist); \
	    strlist_dispose (tlist); \
	  } \
      } \
  } while (0)

#define GEN_XCOMPS(bmap, flag, text, func, cmatches, glist, tlist) \
  do { \
    if (bmap & flag) \
      { \
	cmatches = rl_completion_matches (text, func); \
	tlist = completions_to_stringlist (cmatches); \
	glist = strlist_append (glist, tlist); \
	strvec_dispose (cmatches); \
	strlist_dispose (tlist); \
      } \
  } while (0)

/* Functions to generate lists of matches from the actions member of CS. */

static STRINGLIST *
gen_action_completions (cs, text)
     COMPSPEC *cs;
     const char *text;
{
  STRINGLIST *ret, *tmatches;
  char **cmatches;	/* from rl_completion_matches ... */
  unsigned long flags;
  int t;

  ret = tmatches = (STRINGLIST *)NULL;
  flags = cs->actions;

  GEN_COMPS (flags, CA_ALIAS, &it_aliases, text, ret, tmatches);
  GEN_COMPS (flags, CA_ARRAYVAR, &it_arrayvars, text, ret, tmatches);
  GEN_COMPS (flags, CA_BINDING, &it_bindings, text, ret, tmatches);
  GEN_COMPS (flags, CA_BUILTIN, &it_builtins, text, ret, tmatches);
  GEN_COMPS (flags, CA_DISABLED, &it_disabled, text, ret, tmatches);
  GEN_COMPS (flags, CA_ENABLED, &it_enabled, text, ret, tmatches);
  GEN_COMPS (flags, CA_EXPORT, &it_exports, text, ret, tmatches);
  GEN_COMPS (flags, CA_FUNCTION, &it_functions, text, ret, tmatches);
  GEN_COMPS (flags, CA_HELPTOPIC, &it_helptopics, text, ret, tmatches);
  GEN_COMPS (flags, CA_HOSTNAME, &it_hostnames, text, ret, tmatches);
  GEN_COMPS (flags, CA_JOB, &it_jobs, text, ret, tmatches);
  GEN_COMPS (flags, CA_KEYWORD, &it_keywords, text, ret, tmatches);
  GEN_COMPS (flags, CA_RUNNING, &it_running, text, ret, tmatches);
  GEN_COMPS (flags, CA_SETOPT, &it_setopts, text, ret, tmatches);
  GEN_COMPS (flags, CA_SHOPT, &it_shopts, text, ret, tmatches);
  GEN_COMPS (flags, CA_SIGNAL, &it_signals, text, ret, tmatches);
  GEN_COMPS (flags, CA_STOPPED, &it_stopped, text, ret, tmatches);
  GEN_COMPS (flags, CA_VARIABLE, &it_variables, text, ret, tmatches);

  GEN_XCOMPS(flags, CA_COMMAND, text, command_word_completion_function, cmatches, ret, tmatches);
  GEN_XCOMPS(flags, CA_FILE, text, pcomp_filename_completion_function, cmatches, ret, tmatches);
  GEN_XCOMPS(flags, CA_USER, text, rl_username_completion_function, cmatches, ret, tmatches);
  GEN_XCOMPS(flags, CA_GROUP, text, bash_groupname_completion_function, cmatches, ret, tmatches);
  GEN_XCOMPS(flags, CA_SERVICE, text, bash_servicename_completion_function, cmatches, ret, tmatches);

  /* And lastly, the special case for directories */
  if (flags & CA_DIRECTORY)
    {
      t = rl_filename_completion_desired;
      rl_completion_mark_symlink_dirs = 1;	/* override user preference */
      cmatches = bash_directory_completion_matches (text);
      /* If we did not want filename completion before this, and there are
	 no matches, turn off rl_filename_completion_desired so whatever
	 matches we get are not treated as filenames (it gets turned on by
	 rl_filename_completion_function unconditionally). */
      if (t == 0 && cmatches == 0 && rl_filename_completion_desired == 1)
        rl_filename_completion_desired = 0;
      tmatches = completions_to_stringlist (cmatches);
      ret = strlist_append (ret, tmatches);
      strvec_dispose (cmatches);
      strlist_dispose (tmatches);
    }

  return ret;
}

/* Generate a list of matches for CS->globpat.  Unresolved: should this use
   TEXT as a match prefix, or just go without?  Currently, the code does not
   use TEXT, just globs CS->globpat and returns the results.  If we do decide
   to use TEXT, we should call quote_string_for_globbing before the call to
   glob_filename. */
static STRINGLIST *
gen_globpat_matches (cs, text)
      COMPSPEC *cs;
      const char *text;
{
  STRINGLIST *sl;

  sl = strlist_create (0);
  sl->list = glob_filename (cs->globpat, 0);
  if (GLOB_FAILED (sl->list))
    sl->list = (char **)NULL;
  if (sl->list)
    sl->list_len = sl->list_size = strvec_len (sl->list);
  return sl;
}

/* Perform the shell word expansions on CS->words and return the results.
   Again, this ignores TEXT. */
static STRINGLIST *
gen_wordlist_matches (cs, text)
     COMPSPEC *cs;
     const char *text;
{
  WORD_LIST *l, *l2;
  STRINGLIST *sl;
  int nw, tlen;
  char *ntxt;		/* dequoted TEXT to use in comparisons */

  if (cs->words == 0 || cs->words[0] == '\0')
    return ((STRINGLIST *)NULL);

  /* This used to be a simple expand_string(cs->words, 0), but that won't
     do -- there's no way to split a simple list into individual words
     that way, since the shell semantics say that word splitting is done
     only on the results of expansion.  split_at_delims also handles embedded
     quoted strings and preserves the quotes for the expand_words_shellexp
     function call that follows. */
  /* XXX - this is where this function spends most of its time */
  l = split_at_delims (cs->words, strlen (cs->words), (char *)NULL, -1, 0, (int *)NULL, (int *)NULL);
  if (l == 0)
    return ((STRINGLIST *)NULL);
  /* This will jump back to the top level if the expansion fails... */
  l2 = expand_words_shellexp (l);
  dispose_words (l);

  nw = list_length (l2);
  sl = strlist_create (nw + 1);

  ntxt = bash_dequote_text (text);
  tlen = STRLEN (ntxt);

  for (nw = 0, l = l2; l; l = l->next)
    {
      if (tlen == 0 || STREQN (l->word->word, ntxt, tlen))
	sl->list[nw++] = STRDUP (l->word->word);
    }
  sl->list[sl->list_len = nw] = (char *)NULL;

  dispose_words (l2);
  FREE (ntxt);
  return sl;
}

#ifdef ARRAY_VARS

static SHELL_VAR *
bind_comp_words (lwords)
     WORD_LIST *lwords;
{
  SHELL_VAR *v;

  v = find_variable_noref ("COMP_WORDS");
  if (v == 0)
    v = make_new_array_variable ("COMP_WORDS");
  if (nameref_p (v))
    VUNSETATTR (v, att_nameref);
#if 0
  if (readonly_p (v))
    VUNSETATTR (v, att_readonly);
#endif
  if (array_p (v) == 0)
    v = convert_var_to_array (v);
  v = assign_array_var_from_word_list (v, lwords, 0);

  VUNSETATTR (v, att_invisible);
  return v;
}
#endif /* ARRAY_VARS */

static void
bind_compfunc_variables (line, ind, lwords, cw, exported)
     char *line;
     int ind;
     WORD_LIST *lwords;
     int cw, exported;
{
  char ibuf[INT_STRLEN_BOUND(int) + 1];
  char *value;
  SHELL_VAR *v;
  size_t llen;
  int c;

  /* Set the variables that the function expects while it executes.  Maybe
     these should be in the function environment (temporary_env). */
  v = bind_variable ("COMP_LINE", line, 0);
  if (v && exported)
    VSETATTR(v, att_exported);

  /* Post bash-4.2: COMP_POINT is characters instead of bytes. */
  c = line[ind];
  line[ind] = '\0';
  llen = MB_STRLEN (line);
  line[ind] = c;
  value = inttostr (llen, ibuf, sizeof(ibuf));
  v = bind_int_variable ("COMP_POINT", value, 0);
  if (v && exported)
    VSETATTR(v, att_exported);

  value = inttostr (rl_completion_type, ibuf, sizeof (ibuf));
  v = bind_int_variable ("COMP_TYPE", value, 0);
  if (v && exported)
    VSETATTR(v, att_exported);

  value = inttostr (rl_completion_invoking_key, ibuf, sizeof (ibuf));
  v = bind_int_variable ("COMP_KEY", value, 0);
  if (v && exported)
    VSETATTR(v, att_exported);

  /* Since array variables can't be exported, we don't bother making the
     array of words. */
  if (exported == 0)
    {
#ifdef ARRAY_VARS
      v = bind_comp_words (lwords);
      value = inttostr (cw, ibuf, sizeof(ibuf));
      bind_int_variable ("COMP_CWORD", value, 0);
#endif
    }
  else
    array_needs_making = 1;
}

static void
unbind_compfunc_variables (exported)
     int exported;
{
  unbind_variable_noref ("COMP_LINE");
  unbind_variable_noref ("COMP_POINT");
  unbind_variable_noref ("COMP_TYPE");
  unbind_variable_noref ("COMP_KEY");
#ifdef ARRAY_VARS
  unbind_variable_noref ("COMP_WORDS");
  unbind_variable_noref ("COMP_CWORD");
#endif
  if (exported)
    array_needs_making = 1;
}

/* Build the list of words to pass to a function or external command
   as arguments.  When the function or command is invoked,

	$0 == function or command being invoked
   	$1 == command name
   	$2 == word to be completed (possibly null)
   	$3 == previous word

   Functions can access all of the words in the current command line
   with the COMP_WORDS array.  External commands cannot; they have to
   make do with the COMP_LINE and COMP_POINT variables. */

static WORD_LIST *
build_arg_list (cmd, cname, text, lwords, ind)
     char *cmd;
     const char *cname;
     const char *text;
     WORD_LIST *lwords;
     int ind;
{
  WORD_LIST *ret, *cl, *l;
  WORD_DESC *w;
  int i;

  ret = (WORD_LIST *)NULL;
  w = make_word (cmd);
  ret = make_word_list (w, (WORD_LIST *)NULL);	/* $0 */

  w = make_word (cname);			/* $1 */
  cl = ret->next = make_word_list (w, (WORD_LIST *)NULL);

  w = make_word (text);
  cl->next = make_word_list (w, (WORD_LIST *)NULL);	/* $2 */
  cl = cl->next;

  /* Search lwords for current word */
  for (l = lwords, i = 1; l && i < ind-1; l = l->next, i++)
    ;
  w = (l && l->word) ? copy_word (l->word) : make_word ("");
  cl->next = make_word_list (w, (WORD_LIST *)NULL);

  return ret;
}

/* Build a command string with
	$0 == cs->funcname	(function to execute for completion list)
   	$1 == command name	(command being completed)
   	$2 = word to be completed (possibly null)
   	$3 = previous word
   and run in the current shell.  The function should put its completion
   list into the array variable COMPREPLY.  We build a STRINGLIST
   from the results and return it.

   Since the shell function should return its list of matches in an array
   variable, this does nothing if arrays are not compiled into the shell. */

static STRINGLIST *
gen_shell_function_matches (cs, cmd, text, line, ind, lwords, nw, cw, foundp)
     COMPSPEC *cs;
     const char *cmd;
     const char *text;
     char *line;
     int ind;
     WORD_LIST *lwords;
     int nw, cw;
     int *foundp;
{
  char *funcname;
  STRINGLIST *sl;
  SHELL_VAR *f, *v;
  WORD_LIST *cmdlist;
  int fval, found;
  sh_parser_state_t ps;
  sh_parser_state_t * restrict pps;
#if defined (ARRAY_VARS)
  ARRAY *a;
#endif

  found = 0;
  if (foundp)
    *foundp = found;

  funcname = cs->funcname;
  f = find_function (funcname);
  if (f == 0)
    {
      internal_error (_("completion: function `%s' not found"), funcname);
      rl_ding ();
      rl_on_new_line ();
      return ((STRINGLIST *)NULL);
    }

#if !defined (ARRAY_VARS)
  return ((STRINGLIST *)NULL);
#else

  /* We pass cw - 1 because command_line_to_word_list returns indices that are
     1-based, while bash arrays are 0-based. */
  bind_compfunc_variables (line, ind, lwords, cw - 1, 0);

  cmdlist = build_arg_list (funcname, cmd, text, lwords, cw);

  pps = &ps;
  save_parser_state (pps);
  begin_unwind_frame ("gen-shell-function-matches");
  add_unwind_protect (restore_parser_state, (char *)pps);
  add_unwind_protect (dispose_words, (char *)cmdlist);
  add_unwind_protect (unbind_compfunc_variables, (char *)0);

  fval = execute_shell_function (f, cmdlist);  

  discard_unwind_frame ("gen-shell-function-matches");
  restore_parser_state (pps);

  found = fval != EX_NOTFOUND;
  if (fval == EX_RETRYFAIL)
    found |= PCOMP_RETRYFAIL;
  if (foundp)
    *foundp = found;

  /* Now clean up and destroy everything. */
  dispose_words (cmdlist);
  unbind_compfunc_variables (0);

  /* The list of completions is returned in the array variable COMPREPLY. */
  v = find_variable ("COMPREPLY");
  if (v == 0)
    return ((STRINGLIST *)NULL);
  if (array_p (v) == 0 && assoc_p (v) == 0)
    v = convert_var_to_array (v);

  VUNSETATTR (v, att_invisible);

  a = array_cell (v);
  if (found == 0 || (found & PCOMP_RETRYFAIL) || a == 0 || array_p (v) == 0 || array_empty (a))
    sl = (STRINGLIST *)NULL;
  else
    {
      /* XXX - should we filter the list of completions so only those matching
	 TEXT are returned?  Right now, we do not. */
      sl = strlist_create (0);
      sl->list = array_to_argv (a);
      sl->list_len = sl->list_size = array_num_elements (a);
    }

  /* XXX - should we unbind COMPREPLY here? */
  unbind_variable_noref ("COMPREPLY");

  return (sl);
#endif
}

/* Build a command string with
	$0 == cs->command	(command to execute for completion list)
   	$1 == command name	(command being completed)
	$2 == word to be completed (possibly null)
	$3 == previous word
   and run it with command substitution.  Parse the results, one word
   per line, with backslashes allowed to escape newlines.  Build a
   STRINGLIST from the results and return it. */

static STRINGLIST *
gen_command_matches (cs, cmd, text, line, ind, lwords, nw, cw)
     COMPSPEC *cs;
     const char *cmd;
     const char *text;
     char *line;
     int ind;
     WORD_LIST *lwords;
     int nw, cw;
{
  char *csbuf, *cscmd, *t;
  int cmdlen, cmdsize, n, ws, we;
  WORD_LIST *cmdlist, *cl;
  WORD_DESC *tw;
  STRINGLIST *sl;

  bind_compfunc_variables (line, ind, lwords, cw, 1);
  cmdlist = build_arg_list (cs->command, cmd, text, lwords, cw);

  /* Estimate the size needed for the buffer. */
  n = strlen (cs->command);
  cmdsize = n + 1;
  for (cl = cmdlist->next; cl; cl = cl->next)
    cmdsize += STRLEN (cl->word->word) + 3;
  cmdsize += 2;

  /* allocate the string for the command and fill it in. */
  cscmd = (char *)xmalloc (cmdsize + 1);

  strcpy (cscmd, cs->command);			/* $0 */
  cmdlen = n;
  cscmd[cmdlen++] = ' ';
  for (cl = cmdlist->next; cl; cl = cl->next)   /* $1, $2, $3, ... */
    {
      t = sh_single_quote (cl->word->word ? cl->word->word : "");
      n = strlen (t);
      RESIZE_MALLOCED_BUFFER (cscmd, cmdlen, n + 2, cmdsize, 64);
      strcpy (cscmd + cmdlen, t);
      cmdlen += n;
      if (cl->next)
	cscmd[cmdlen++] = ' ';
      free (t);
    }
  cscmd[cmdlen] = '\0';

  tw = command_substitute (cscmd, 0, 0);
  csbuf = tw ? tw->word : (char *)NULL;
  if (tw)
    dispose_word_desc (tw);

  /* Now clean up and destroy everything. */
  dispose_words (cmdlist);
  free (cscmd);
  unbind_compfunc_variables (1);

  if (csbuf == 0 || *csbuf == '\0')
    {
      FREE (csbuf);
      return ((STRINGLIST *)NULL);
    }

  /* Now break CSBUF up at newlines, with backslash allowed to escape a
     newline, and put the individual words into a STRINGLIST. */
  sl = strlist_create (16);
  for (ws = 0; csbuf[ws]; )
    {
      we = ws;
      while (csbuf[we] && csbuf[we] != '\n')
	{
	  if (csbuf[we] == '\\' && csbuf[we+1] == '\n')
	    we++;
	  we++;
	}
      t = substring (csbuf, ws, we);
      if (sl->list_len >= sl->list_size - 1)
	strlist_resize (sl, sl->list_size + 16);
      sl->list[sl->list_len++] = t;
      while (csbuf[we] == '\n') we++;
      ws = we;
    }
  sl->list[sl->list_len] = (char *)NULL;

  free (csbuf);
  return (sl);
}

static WORD_LIST *
command_line_to_word_list (line, llen, sentinel, nwp, cwp)
     char *line;
     int llen, sentinel, *nwp, *cwp;
{
  WORD_LIST *ret;
  char *delims;

#if 0
  delims = "()<>;&| \t\n";	/* shell metacharacters break words */
#else
  delims = rl_completer_word_break_characters;
#endif
  ret = split_at_delims (line, llen, delims, sentinel, SD_NOQUOTEDELIM|SD_COMPLETE, nwp, cwp);
  return (ret);
}

/* Evaluate COMPSPEC *cs and return all matches for WORD. */

STRINGLIST *
gen_compspec_completions (cs, cmd, word, start, end, foundp)
     COMPSPEC *cs;
     const char *cmd;
     const char *word;
     int start, end;
     int *foundp;
{
  STRINGLIST *ret, *tmatches;
  char *line;
  int llen, nw, cw, found, foundf;
  WORD_LIST *lwords;
  WORD_DESC *lw;
  COMPSPEC *tcs;

  found = 1;

#ifdef DEBUG
  debug_printf ("gen_compspec_completions (%s, %s, %d, %d)", cmd, word, start, end);
  debug_printf ("gen_compspec_completions: %s -> %p", cmd, cs);
#endif
  ret = gen_action_completions (cs, word);
#ifdef DEBUG
  if (ret && progcomp_debug)
    {
      debug_printf ("gen_action_completions (%p, %s) -->", cs, word);
      strlist_print (ret, "\t");
      rl_on_new_line ();
    }
#endif

  /* Now we start generating completions based on the other members of CS. */
  if (cs->globpat)
    {
      tmatches = gen_globpat_matches (cs, word);
      if (tmatches)
	{
#ifdef DEBUG
	  if (progcomp_debug)
	    {
	      debug_printf ("gen_globpat_matches (%p, %s) -->", cs, word);
	      strlist_print (tmatches, "\t");
	      rl_on_new_line ();
	    }
#endif
	  ret = strlist_append (ret, tmatches);
	  strlist_dispose (tmatches);
	  rl_filename_completion_desired = 1;
	}
    }

  if (cs->words)
    {
      tmatches = gen_wordlist_matches (cs, word);
      if (tmatches)
	{
#ifdef DEBUG
	  if (progcomp_debug)
	    {
	      debug_printf ("gen_wordlist_matches (%p, %s) -->", cs, word);
	      strlist_print (tmatches, "\t");
	      rl_on_new_line ();
	    }
#endif
	  ret = strlist_append (ret, tmatches);
	  strlist_dispose (tmatches);
	}
    }

  lwords = (WORD_LIST *)NULL;
  line = (char *)NULL;
  if (cs->command || cs->funcname)
    {
      /* If we have a command or function to execute, we need to first break
	 the command line into individual words, find the number of words,
	 and find the word in the list containing the word to be completed. */
      line = substring (pcomp_line, start, end);
      llen = end - start;

#ifdef DEBUG
      debug_printf ("command_line_to_word_list (%s, %d, %d, %p, %p)",
		line, llen, pcomp_ind - start, &nw, &cw);
#endif
      lwords = command_line_to_word_list (line, llen, pcomp_ind - start, &nw, &cw);
      /* If we skipped a NULL word at the beginning of the line, add it back */
      if (lwords && lwords->word && cmd[0] == 0 && lwords->word->word[0] != 0)
	{
	  lw = make_bare_word (cmd);
	  lwords = make_word_list (lw, lwords);
	  nw++;
	  cw++;
	}
#ifdef DEBUG
      if (lwords == 0 && llen > 0)
	debug_printf ("ERROR: command_line_to_word_list returns NULL");
      else if (progcomp_debug)
	{
	  debug_printf ("command_line_to_word_list -->");
	  printf ("\t");
	  print_word_list (lwords, "!");
	  printf ("\n");
	  fflush(stdout);
	  rl_on_new_line ();
	}
#endif
    }

  if (cs->funcname)
    {
      foundf = 0;
      tmatches = gen_shell_function_matches (cs, cmd, word, line, pcomp_ind - start, lwords, nw, cw, &foundf);
      if (foundf != 0)
	found = foundf;
      if (tmatches)
	{
#ifdef DEBUG
	  if (progcomp_debug)
	    {
	      debug_printf ("gen_shell_function_matches (%p, %s, %s, %p, %d, %d) -->", cs, cmd, word, lwords, nw, cw);
	      strlist_print (tmatches, "\t");
	      rl_on_new_line ();
	    }
#endif
	  ret = strlist_append (ret, tmatches);
	  strlist_dispose (tmatches);
	}
    }

  if (cs->command)
    {
      tmatches = gen_command_matches (cs, cmd, word, line, pcomp_ind - start, lwords, nw, cw);
      if (tmatches)
	{
#ifdef DEBUG
	  if (progcomp_debug)
	    {
	      debug_printf ("gen_command_matches (%p, %s, %s, %p, %d, %d) -->", cs, cmd, word, lwords, nw, cw);
	      strlist_print (tmatches, "\t");
	      rl_on_new_line ();
	    }
#endif
	  ret = strlist_append (ret, tmatches);
	  strlist_dispose (tmatches);
	}
    }

  if (cs->command || cs->funcname)
    {
      if (lwords)
	dispose_words (lwords);
      FREE (line);
    }

  if (foundp)
    *foundp = found;

  if (found == 0 || (found & PCOMP_RETRYFAIL))
    {
      strlist_dispose (ret);
      return NULL;
    }

  if (cs->filterpat)
    {
      tmatches = filter_stringlist (ret, cs->filterpat, word);
#ifdef DEBUG
      if (progcomp_debug)
	{
	  debug_printf ("filter_stringlist (%p, %s, %s) -->", ret, cs->filterpat, word);
	  strlist_print (tmatches, "\t");
	  rl_on_new_line ();
	}
#endif
      if (ret && ret != tmatches)
	{
	  FREE (ret->list);
	  free (ret);
	}
      ret = tmatches;
    }

  if (cs->prefix || cs->suffix)
    ret = strlist_prefix_suffix (ret, cs->prefix, cs->suffix);

  /* If no matches have been generated and the user has specified that
      directory completion should be done as a default, call
      gen_action_completions again to generate a list of matching directory
      names. */
  if ((ret == 0 || ret->list_len == 0) && (cs->options & COPT_DIRNAMES))
    {
      tcs = compspec_create ();
      tcs->actions = CA_DIRECTORY;
      FREE (ret);
      ret = gen_action_completions (tcs, word);
      compspec_dispose (tcs);
    }
  else if (cs->options & COPT_PLUSDIRS)
    {
      tcs = compspec_create ();
      tcs->actions = CA_DIRECTORY;
      tmatches = gen_action_completions (tcs, word);
      ret = strlist_append (ret, tmatches);
      strlist_dispose (tmatches);
      compspec_dispose (tcs);
    }

  return (ret);
}

void
pcomp_set_readline_variables (flags, nval)
     int flags, nval;
{
  /* If the user specified that the compspec returns filenames, make
     sure that readline knows it. */
  if (flags & COPT_FILENAMES)
    rl_filename_completion_desired = nval;
  /* If the user doesn't want a space appended, tell readline. */
  if (flags & COPT_NOSPACE)
    rl_completion_suppress_append = nval;
  /* The value here is inverted, since the default is on and the `noquote'
     option is supposed to turn it off */
  if (flags & COPT_NOQUOTE)
    rl_filename_quoting_desired = 1 - nval;
  if (flags & COPT_NOSORT)
    rl_sort_completion_matches = 1 - nval;
}

/* Set or unset FLAGS in the options word of the current compspec.
   SET_OR_UNSET is 1 for setting, 0 for unsetting. */
void
pcomp_set_compspec_options (cs, flags, set_or_unset)
     COMPSPEC *cs;
     int flags, set_or_unset;
{
  if (cs == 0 && ((cs = pcomp_curcs) == 0))
    return;
  if (set_or_unset)
    cs->options |= flags;
  else
    cs->options &= ~flags;
}

static STRINGLIST *
gen_progcomp_completions (ocmd, cmd, word, start, end, foundp, retryp, lastcs)
     const char *ocmd;
     const char *cmd;
     const char *word;
     int start, end;
     int *foundp, *retryp;
     COMPSPEC **lastcs;
{
  COMPSPEC *cs, *oldcs;
  const char *oldcmd, *oldtxt;
  STRINGLIST *ret;

  cs = progcomp_search (ocmd);

  if (cs == 0 || cs == *lastcs)
    {
#if 0
      if (foundp)
	*foundp = 0;
#endif
      return (NULL);
    }

  if (*lastcs)
    compspec_dispose (*lastcs);
  cs->refcount++;	/* XXX */
  *lastcs = cs;

  cs = compspec_copy (cs);

  oldcs = pcomp_curcs;
  oldcmd = pcomp_curcmd;
  oldtxt = pcomp_curtxt;

  pcomp_curcs = cs;
  pcomp_curcmd = cmd;
  pcomp_curtxt = word;

  ret = gen_compspec_completions (cs, cmd, word, start, end, foundp);

  pcomp_curcs = oldcs;
  pcomp_curcmd = oldcmd;
  pcomp_curtxt = oldtxt;

  /* We need to conditionally handle setting *retryp here */
  if (retryp)
    *retryp = foundp && (*foundp & PCOMP_RETRYFAIL);    	

  if (foundp)
    {
      *foundp &= ~PCOMP_RETRYFAIL;
      *foundp |= cs->options;
    }

  compspec_dispose (cs);
  return ret;  
}

/* The driver function for the programmable completion code.  Returns a list
   of matches for WORD, which is an argument to command CMD.  START and END
   bound the command currently being completed in pcomp_line (usually
   rl_line_buffer). */
char **
programmable_completions (cmd, word, start, end, foundp)
     const char *cmd;
     const char *word;
     int start, end, *foundp;
{
  COMPSPEC *lastcs;
  STRINGLIST *ret;
  char **rmatches, *t;
  int found, retry, count;
  char *ocmd;
  int oend;
#if defined (ALIAS)
  alias_t *al;
#endif

  lastcs = 0;
  found = count = 0;

  pcomp_line = rl_line_buffer;
  pcomp_ind = rl_point;

  ocmd = (char *)cmd;
  oend = end;

  do
    {
      retry = 0;

      /* We look at the basename of CMD if the full command does not have
	 an associated COMPSPEC. */
      ret = gen_progcomp_completions (ocmd, ocmd, word, start, oend, &found, &retry, &lastcs);
      if (found == 0)
	{
	  t = strrchr (ocmd, '/');
	  if (t && *(++t))
	    ret = gen_progcomp_completions (t, ocmd, word, start, oend, &found, &retry, &lastcs);
	}

      if (found == 0)
	ret = gen_progcomp_completions (DEFAULTCMD, ocmd, word, start, oend, &found, &retry, &lastcs);

#if defined (ALIAS)
      /* Look up any alias for CMD, try to gen completions for it */
      /* Look up the alias, find the value, build a new line replacing CMD
	 with that value, offsetting PCOMP_IND and END appropriately, reset
	 PCOMP_LINE to the new line and OCMD with the new command name, then
	 call gen_progcomp_completions again. We could use alias_expand for
	 this, but it does more (and less) than we need right now. */
      if (found == 0 && retry == 0 && progcomp_alias && (al = find_alias (ocmd)))
	{
	  char *ncmd, *nline, *ntxt;
	  int ind, lendiff;
	  size_t nlen, olen, llen;

	  /* We found an alias for OCMD. Take the value and build a new line */
	  ntxt = al->value;
	  nlen = strlen (ntxt);
	  if (nlen == 0)
	    break;
	  olen = strlen (ocmd);
	  lendiff = nlen - olen;	/* can be negative */
	  llen = strlen (pcomp_line);

	  nline = (char *)xmalloc (llen + lendiff + 1);
	  if (start > 0)
	    strncpy (nline, pcomp_line, start);
	  strncpy (nline + start, ntxt, nlen);
	  strcpy (nline + start + nlen, pcomp_line + start + olen);

	  /* Find the first word of the alias value and use that as OCMD. We
	     don't check the alias value to see whether it begins with a valid
	     command name, so this can be fooled. */
	  ind = skip_to_delim (ntxt, 0, "()<>;&| \t\n", SD_NOJMP|SD_COMPLETE);
	  if (ind > 0)
	    ncmd = substring (ntxt, 0, ind);
	  else
	    {
	      free (nline);
	      break;		/* will free pcomp_line and ocmd later */
	    }

	  /* Adjust PCOMP_IND and OEND appropriately */
	  pcomp_ind += lendiff;
	  oend += lendiff;

	  /* Set up values with new line. WORD stays the same. */
	  if (ocmd != cmd)
	    free (ocmd);
	  if (pcomp_line != rl_line_buffer)
	    free (pcomp_line);

	  ocmd = ncmd;
	  pcomp_line = nline;

	  /* And go back and start over. */
	  retry = 1;
	}
#endif /* ALIAS */

      count++;

      if (count > 32)
	{
	  internal_warning (_("programmable_completion: %s: possible retry loop"), cmd);
	  break;
	}
    }
  while (retry);

  if (pcomp_line != rl_line_buffer)
    free (pcomp_line);
  if (ocmd != cmd)
    free (ocmd);

  if (ret)
    {
      rmatches = ret->list;
      free (ret);
    }
  else
    rmatches = (char **)NULL;

  if (foundp)
    *foundp = found;

  if (lastcs)	/* XXX - should be while? */
    compspec_dispose (lastcs);

  /* XXX restore pcomp_line and pcomp_ind? */
  pcomp_line = rl_line_buffer;
  pcomp_ind = rl_point;

  return (rmatches);
}

#endif /* PROGRAMMABLE_COMPLETION */