path: root/src/wgetopt.cpp

/** \file wgetopt.c
  A version of the getopt library for use with wide character strings.

  This is simply the gnu getopt library, but converted for use with
  wchar_t instead of char. This is not usually useful since the argv
  array is always defined to be of type char**, but in fish, all
  internal commands use wide characters and hence this library is
  useful.

  If you want to use this version of getopt in your program,
  download the fish sourcecode, available at <a
  href='http://fishshell.com'>the fish homepage</a>. Extract
  the sourcode, copy wgetopt.c and wgetopt.h into your program
  directory, include wgetopt.h in your program, and use all the
  regular getopt functions, prefixing every function, global
  variable and structure with a 'w', and use only wide character
  strings. There are no other functional changes in this version of
  getopt besides using wide character strings.

  For examples of how to use wgetopt, see the fish builtin
  functions, many of which are defined in builtin.c.

*/


/* Getopt for GNU.
   NOTE: getopt is now part of the C library, so if you don't know what
   "Keep this file name-space clean" means, talk to roland@gnu.ai.mit.edu
   before changing it!

   Copyright (C) 1987, 88, 89, 90, 91, 92, 93, 94
   Free Software Foundation, Inc.

   This file is part of the GNU C Library.  Its master source is NOT part of
   the C library, however.  The master source lives in /gd/gnu/lib.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If
   not, write to the Free Software Foundation, Inc., 675 Mass Ave,
   Cambridge, MA 02139, USA.  */

#include "config.h"

#include <stdio.h>
#include <wchar.h>
/* This needs to come after some library #include
   to get __GNU_LIBRARY__ defined.  */
#ifdef  __GNU_LIBRARY__
/* Don't include stdlib.h for non-GNU C libraries because some of them
   contain conflicting prototypes for getopt.  */
#include <stdlib.h>
#endif  /* GNU C library.  */

/* This version of `getopt' appears to the caller like standard Unix `getopt'
   but it behaves differently for the user, since it allows the user
   to intersperse the options with the other arguments.

   As `getopt' works, it permutes the elements of ARGV so that,
   when it is done, all the options precede everything else.  Thus
   all application programs are extended to handle flexible argument order.

   GNU application programs can use a third alternative mode in which
   they can distinguish the relative order of options and other arguments.  */

#include "common.h"
#include "wgetopt.h"
#include "wutil.h"  // IWYU pragma: keep
#include "fallback.h" // IWYU pragma: keep

/**
   Use translation functions if available
*/
#ifdef _
#undef _
#endif

#ifdef HAVE_TRANSLATE_H
#ifdef USE_GETTEXT
#define _(string) wgettext(string)
#else
#define _(string) (string)
#endif
#else
#define _(wstr) wstr
#endif

#ifdef  __GNU_LIBRARY__
/* We want to avoid inclusion of string.h with non-GNU libraries
   because there are many ways it can cause trouble.
   On some systems, it contains special magic macros that don't work
   in GCC.  */
#include <string.h> // IWYU pragma: keep
#define  my_index  wcschr
#else

/* Avoid depending on library functions or files
   whose names are inconsistent.  */

char *getenv();

static wchar_t *
my_index(const wchar_t *str, int chr)
{
    while (*str)
    {
        if (*str == chr)
            return (wchar_t *) str;
        str++;
    }
    return 0;
}

/* If using GCC, we can safely declare strlen this way.
   If not using GCC, it is ok not to declare it.  */
#ifdef __GNUC__
/* Note that Motorola Delta 68k R3V7 comes with GCC but not stddef.h.
   That was relevant to code that was here before.  */
#if !defined (__STDC__) || !__STDC__
/* gcc with -traditional declares the built-in strlen to return int,
   and has done so at least since version 2.4.5. -- rms.  */
extern int wcslen(const wchar_t *);
#endif /* not __STDC__ */
#endif /* __GNUC__ */

#endif /* not __GNU_LIBRARY__ */


/* Exchange two adjacent subsequences of ARGV.
   One subsequence is elements [first_nonopt,last_nonopt)
   which contains all the non-options that have been skipped so far.
   The other is elements [last_nonopt,woptind), which contains all
   the options processed since those non-options were skipped.

   `first_nonopt' and `last_nonopt' are relocated so that they describe
   the new indices of the non-options in ARGV after they are moved.  */

void wgetopter_t::exchange(wchar_t **argv)
{
    int bottom = first_nonopt;
    int middle = last_nonopt;
    int top = woptind;
    wchar_t *tem;

    /* Exchange the shorter segment with the far end of the longer segment.
       That puts the shorter segment into the right place.
       It leaves the longer segment in the right place overall,
       but it consists of two parts that need to be swapped next.  */

    while (top > middle && middle > bottom)
    {
        if (top - middle > middle - bottom)
        {
            /* Bottom segment is the short one.  */
            int len = middle - bottom;
            int i;

            /* Swap it with the top part of the top segment.  */
            for (i = 0; i < len; i++)
            {
                tem = argv[bottom + i];
                argv[bottom + i] = argv[top - (middle - bottom) + i];
                argv[top - (middle - bottom) + i] = tem;
            }
            /* Exclude the moved bottom segment from further swapping.  */
            top -= len;
        }
        else
        {
            /* Top segment is the short one.  */
            int len = top - middle;
            int i;

            /* Swap it with the bottom part of the bottom segment.  */
            for (i = 0; i < len; i++)
            {
                tem = argv[bottom + i];
                argv[bottom + i] = argv[middle + i];
                argv[middle + i] = tem;
            }
            /* Exclude the moved top segment from further swapping.  */
            bottom += len;
        }
    }

    /* Update records for the slots the non-options now occupy.  */

    first_nonopt += (woptind - last_nonopt);
    last_nonopt = woptind;
}

/* Initialize the internal data when the first call is made.  */

const wchar_t * wgetopter_t::_wgetopt_initialize(const wchar_t *optstring)
{
    /* Start processing options with ARGV-element 1 (since ARGV-element 0
       is the program name); the sequence of previously skipped
       non-option ARGV-elements is empty.  */

    first_nonopt = last_nonopt = woptind = 1;

    nextchar = NULL;

    /* Determine how to handle the ordering of options and nonoptions.  */

    if (optstring[0] == '-')
    {
        ordering = RETURN_IN_ORDER;
        ++optstring;
    }
    else if (optstring[0] == '+')
    {
        ordering = REQUIRE_ORDER;
        ++optstring;
    }
    else
        ordering = PERMUTE;

    return optstring;
}

/* Scan elements of ARGV (whose length is ARGC) for option characters
   given in OPTSTRING.

   If an element of ARGV starts with '-', and is not exactly "-" or "--",
   then it is an option element.  The characters of this element
   (aside from the initial '-') are option characters.  If `getopt'
   is called repeatedly, it returns successively each of the option characters
   from each of the option elements.

   If `getopt' finds another option character, it returns that character,
   updating `woptind' and `nextchar' so that the next call to `getopt' can
   resume the scan with the following option character or ARGV-element.

   If there are no more option characters, `getopt' returns `EOF'.
   Then `woptind' is the index in ARGV of the first ARGV-element
   that is not an option.  (The ARGV-elements have been permuted
   so that those that are not options now come last.)

   OPTSTRING is a string containing the legitimate option characters.
   If an option character is seen that is not listed in OPTSTRING,
   return '?' after printing an error message.  If you set `wopterr' to
   zero, the error message is suppressed but we still return '?'.

   If a char in OPTSTRING is followed by a colon, that means it wants an arg,
   so the following text in the same ARGV-element, or the text of the following
   ARGV-element, is returned in `optarg'.  Two colons mean an option that
   wants an optional arg; if there is text in the current ARGV-element,
   it is returned in `w.woptarg', otherwise `w.woptarg' is set to zero.

   If OPTSTRING starts with `-' or `+', it requests different methods of
   handling the non-option ARGV-elements.
   See the comments about RETURN_IN_ORDER and REQUIRE_ORDER, above.

   Long-named options begin with `--' instead of `-'.
   Their names may be abbreviated as long as the abbreviation is unique
   or is an exact match for some defined option.  If they have an
   argument, it follows the option name in the same ARGV-element, separated
   from the option name by a `=', or else the in next ARGV-element.
   When `getopt' finds a long-named option, it returns 0 if that option's
   `flag' field is nonzero, the value of the option's `val' field
   if the `flag' field is zero.

   LONGOPTS is a vector of `struct option' terminated by an
   element containing a name which is zero.

   LONGIND returns the index in LONGOPT of the long-named option found.
   It is only valid when a long-named option has been found by the most
   recent call.

   If LONG_ONLY is nonzero, '-' as well as '--' can introduce
   long-named options.  */

int wgetopter_t::_wgetopt_internal(int argc, wchar_t **argv, const wchar_t *optstring, const struct woption *longopts, int *longind, int long_only)
{
    woptarg = NULL;

    if (woptind == 0)
        optstring = _wgetopt_initialize(optstring);

    if (nextchar == NULL || *nextchar == '\0')
    {
        /* Advance to the next ARGV-element.  */

        if (ordering == PERMUTE)
        {
            /* If we have just processed some options following some non-options,
               exchange them so that the options come first.  */

            if (first_nonopt != last_nonopt && last_nonopt != woptind)
                exchange(argv);
            else if (last_nonopt != woptind)
                first_nonopt = woptind;

            /* Skip any additional non-options
               and extend the range of non-options previously skipped.  */

            while (woptind < argc
                    && (argv[woptind][0] != '-' || argv[woptind][1] == '\0'))
                woptind++;
            last_nonopt = woptind;
        }

        /* The special ARGV-element `--' means premature end of options.
           Skip it like a null option,
           then exchange with previous non-options as if it were an option,
           then skip everything else like a non-option.  */

        if (woptind != argc && !wcscmp(argv[woptind], L"--"))
        {
            woptind++;

            if (first_nonopt != last_nonopt && last_nonopt != woptind)
                exchange(argv);
            else if (first_nonopt == last_nonopt)
                first_nonopt = woptind;
            last_nonopt = argc;

            woptind = argc;
        }

        /* If we have done all the ARGV-elements, stop the scan
           and back over any non-options that we skipped and permuted.  */

        if (woptind == argc)
        {
            /* Set the next-arg-index to point at the non-options
               that we previously skipped, so the caller will digest them.  */
            if (first_nonopt != last_nonopt)
                woptind = first_nonopt;
            return EOF;
        }

        /* If we have come to a non-option and did not permute it,
           either stop the scan or describe it to the caller and pass it by.  */

        if ((argv[woptind][0] != '-' || argv[woptind][1] == '\0'))
        {
            if (ordering == REQUIRE_ORDER)
                return EOF;
            woptarg = argv[woptind++];
            return 1;
        }

        /* We have found another option-ARGV-element.
           Skip the initial punctuation.  */

        nextchar = (argv[woptind] + 1
                    + (longopts != NULL && argv[woptind][1] == '-'));
    }

    /* Decode the current option-ARGV-element.  */

    /* Check whether the ARGV-element is a long option.

    If long_only and the ARGV-element has the form "-f", where f is
    a valid short option, don't consider it an abbreviated form of
    a long option that starts with f.  Otherwise there would be no
    way to give the -f short option.

    On the other hand, if there's a long option "fubar" and
    the ARGV-element is "-fu", do consider that an abbreviation of
    the long option, just like "--fu", and not "-f" with arg "u".

    This distinction seems to be the most useful approach.  */

    if (longopts != NULL
            && (argv[woptind][1] == '-'
                || (long_only && (argv[woptind][2] || !my_index(optstring, argv[woptind][1])))))
    {
        wchar_t *nameend;
        const struct woption *p;
        const struct woption *pfound = NULL;
        int exact = 0;
        int ambig = 0;
        int indfound = 0; /* set to zero by Anton */
        int option_index;

        for (nameend = nextchar; *nameend && *nameend != '='; nameend++)
            /* Do nothing.  */ ;

        /* Test all long options for either exact match
           or abbreviated matches.  */
        for (p = longopts, option_index = 0; p->name; p++, option_index++)
            if (!wcsncmp(p->name, nextchar, nameend - nextchar))
            {
                if ((unsigned int)(nameend - nextchar) == (unsigned int)wcslen(p->name))
                {
                    /* Exact match found.  */
                    pfound = p;
                    indfound = option_index;
                    exact = 1;
                    break;
                }
                else if (pfound == NULL)
                {
                    /* First nonexact match found.  */
                    pfound = p;
                    indfound = option_index;
                }
                else
                    /* Second or later nonexact match found.  */
                    ambig = 1;
            }

        if (ambig && !exact)
        {
            if (wopterr)
                fwprintf(stderr, _(L"%ls: Option '%ls' is ambiguous\n"),
                         argv[0], argv[woptind]);
            nextchar += wcslen(nextchar);
            woptind++;
            return '?';
        }

        if (pfound != NULL)
        {
            option_index = indfound;
            woptind++;
            if (*nameend)
            {
                /* Don't test has_arg with >, because some C compilers don't
                   allow it to be used on enums.  */
                if (pfound->has_arg)
                    woptarg = nameend + 1;
                else
                {
                    if (wopterr)
                    {
                        if (argv[woptind - 1][1] == '-')
                            /* --option */
                            fwprintf(stderr,
                                     _(L"%ls: Option '--%ls' doesn't allow an argument\n"),
                                     argv[0], pfound->name);
                        else
                            /* +option or -option */
                            fwprintf(stderr,
                                     _(L"%ls: Option '%lc%ls' doesn't allow an argument\n"),
                                     argv[0], argv[woptind - 1][0], pfound->name);
                    }
                    nextchar += wcslen(nextchar);
                    return '?';
                }
            }
            else if (pfound->has_arg == 1)
            {
                if (woptind < argc)
                    woptarg = argv[woptind++];
                else
                {
                    if (wopterr)
                        fwprintf(stderr, _(L"%ls: Option '%ls' requires an argument\n"),
                                 argv[0], argv[woptind - 1]);
                    nextchar += wcslen(nextchar);
                    return optstring[0] == ':' ? ':' : '?';
                }
            }
            nextchar += wcslen(nextchar);
            if (longind != NULL)
                *longind = option_index;
            if (pfound->flag)
            {
                *(pfound->flag) = pfound->val;
                return 0;
            }
            return pfound->val;
        }

        /* Can't find it as a long option.  If this is not getopt_long_only,
           or the option starts with '--' or is not a valid short
           option, then it's an error.
           Otherwise interpret it as a short option.  */
        if (!long_only || argv[woptind][1] == '-'
                || my_index(optstring, *nextchar) == NULL)
        {
            if (wopterr)
            {
                if (argv[woptind][1] == '-')
                    /* --option */
                    fwprintf(stderr, _(L"%ls: Unrecognized option '--%ls'\n"),
                             argv[0], nextchar);
                else
                    /* +option or -option */
                    fwprintf(stderr, _(L"%ls: Unrecognized option '%lc%ls'\n"),
                             argv[0], argv[woptind][0], nextchar);
            }
            nextchar = (wchar_t *) L"";
            woptind++;
            return '?';
        }
    }

    /* Look at and handle the next short option-character.  */

    {
        wchar_t c = *nextchar++;
        wchar_t *temp = const_cast<wchar_t*>(my_index(optstring, c));

        /* Increment `woptind' when we start to process its last character.  */
        if (*nextchar == '\0')
            ++woptind;

        if (temp == NULL || c == ':')
        {
            if (wopterr)
            {
                fwprintf(stderr, _(L"%ls: Invalid option -- %lc\n"), argv[0], (wint_t)c);
            }
            woptopt = c;

            if (*nextchar != '\0')
                woptind++;

            return '?';
        }
        if (temp[1] == ':')
        {
            if (temp[2] == ':')
            {
                /* This is an option that accepts an argument optionally.  */
                if (*nextchar != '\0')
                {
                    woptarg = nextchar;
                    woptind++;
                }
                else
                    woptarg = NULL;
                nextchar = NULL;
            }
            else
            {
                /* This is an option that requires an argument.  */
                if (*nextchar != '\0')
                {
                    woptarg = nextchar;
                    /* If we end this ARGV-element by taking the rest as an arg,
                       we must advance to the next element now.  */
                    woptind++;
                }
                else if (woptind == argc)
                {
                    if (wopterr)
                    {
                        /* 1003.2 specifies the format of this message.  */
                        fwprintf(stderr, _(L"%ls: Option requires an argument -- %lc\n"),
                                 argv[0], (wint_t)c);
                    }
                    woptopt = c;
                    if (optstring[0] == ':')
                        c = ':';
                    else
                        c = '?';
                }
                else
                    /* We already incremented `woptind' once;
                       increment it again when taking next ARGV-elt as argument.  */
                    woptarg = argv[woptind++];
                nextchar = NULL;
            }
        }
        return c;
    }
}

int wgetopter_t::wgetopt_long(int argc, wchar_t **argv, const wchar_t *options, const struct woption *long_options, int *opt_index)
{
    return _wgetopt_internal(argc, argv, options, long_options, opt_index, 0);
}

int wgetopter_t::wgetopt_long_only(int argc, wchar_t **argv, const wchar_t *options, const struct woption *long_options, int *opt_index)
{
    return _wgetopt_internal(argc, argv, options, long_options, opt_index, 1);
}