/* File name comparison routine.

   Copyright (C) 2007-2025 Free Software Foundation, Inc.

   This program 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 2, or (at your option)

   any later version.

   This program 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 this program; if not, write to the Free Software Foundation,

   Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#ifdef HAVE_STRING_H

#include <string.h>

#endif

#ifdef HAVE_STDLIB_H

#include <stdlib.h>

#endif

#include "filenames.h"

#include "safe-ctype.h"

#include "libiberty.h"

/*

@deftypefn Extension int filename_cmp (const char *@var{s1}, const char *@var{s2})

Return zero if the two file names @var{s1} and @var{s2} are equivalent.

If not equivalent, the returned value is similar to what @code{strcmp}

would return.  In other words, it returns a negative value if @var{s1}

is less than @var{s2}, or a positive value if @var{s2} is greater than

@var{s2}.

This function does not normalize file names.  As a result, this function

will treat filenames that are spelled differently as different even in

the case when the two filenames point to the same underlying file.

However, it does handle the fact that on DOS-like file systems, forward

and backward slashes are equal.

@end deftypefn

*/

int

filename_cmp (const char *s1, const char *s2)

{

#if !defined(HAVE_DOS_BASED_FILE_SYSTEM) \

    && !defined(HAVE_CASE_INSENSITIVE_FILE_SYSTEM)

  return strcmp(s1, s2);

#else

  for (;;)

    {

      int c1 = *s1;

      int c2 = *s2;

#if defined (HAVE_CASE_INSENSITIVE_FILE_SYSTEM)

      c1 = TOLOWER (c1);

      c2 = TOLOWER (c2);

#endif

#if defined (HAVE_DOS_BASED_FILE_SYSTEM)

      /* On DOS-based file systems, the '/' and the '\' are equivalent.  */

      if (c1 == '/')

        c1 = '\\';

      if (c2 == '/')

        c2 = '\\';

#endif

      if (c1 != c2)

        return (c1 - c2);

      if (c1 == '\0')

        return 0;

      s1++;

      s2++;

    }

#endif

}

/*

@deftypefn Extension int filename_ncmp (const char *@var{s1}, const char *@var{s2}, size_t @var{n})

Return zero if the two file names @var{s1} and @var{s2} are equivalent

in range @var{n}.

If not equivalent, the returned value is similar to what @code{strncmp}

would return.  In other words, it returns a negative value if @var{s1}

is less than @var{s2}, or a positive value if @var{s2} is greater than

@var{s2}.

This function does not normalize file names.  As a result, this function

will treat filenames that are spelled differently as different even in

the case when the two filenames point to the same underlying file.

However, it does handle the fact that on DOS-like file systems, forward

and backward slashes are equal.

@end deftypefn

*/

int

filename_ncmp (const char *s1, const char *s2, size_t n)

{

#if !defined(HAVE_DOS_BASED_FILE_SYSTEM) \

    && !defined(HAVE_CASE_INSENSITIVE_FILE_SYSTEM)

  return strncmp(s1, s2, n);

#else

  if (!n)

    return 0;

  for (; n > 0; --n)

  {

      int c1 = *s1;

      int c2 = *s2;

#if defined (HAVE_CASE_INSENSITIVE_FILE_SYSTEM)

      c1 = TOLOWER (c1);

      c2 = TOLOWER (c2);

#endif

#if defined (HAVE_DOS_BASED_FILE_SYSTEM)

      /* On DOS-based file systems, the '/' and the '\' are equivalent.  */

      if (c1 == '/')

        c1 = '\\';

      if (c2 == '/')

        c2 = '\\';

#endif

      if (c1 == '\0' || c1 != c2)

        return (c1 - c2);

      s1++;

      s2++;

  }

  return 0;

#endif

}

/*

@deftypefn Extension hashval_t filename_hash (const void *@var{s})

Return the hash value for file name @var{s} that will be compared

using filename_cmp.

This function is for use with hashtab.c hash tables.

@end deftypefn

*/

hashval_t

filename_hash (const void *s)

{

  /* The cast is for -Wc++-compat.  */

  const unsigned char *str = (const unsigned char *) s;

  hashval_t r = 0;

  unsigned char c;

  while ((c = *str++) != 0)

    {

      if (c == '\\')

  c = '/';

      c = TOLOWER (c);

      r = r * 67 + c - 113;

    }

  return r;

}

/*

@deftypefn Extension int filename_eq (const void *@var{s1}, const void *@var{s2})

Return non-zero if file names @var{s1} and @var{s2} are equivalent.

This function is for use with hashtab.c hash tables.

@end deftypefn

*/

int

filename_eq (const void *s1, const void *s2)

{

  /* The casts are for -Wc++-compat.  */

  return filename_cmp ((const char *) s1, (const char *) s2) == 0;

}

/*

@deftypefn Extension int canonical_filename_eq (const char *@var{a}, const char *@var{b})

Return non-zero if file names @var{a} and @var{b} are equivalent.

This function compares the canonical versions of the filenames as returned by

@code{lrealpath()}, so that so that different file names pointing to the same

underlying file are treated as being identical.

@end deftypefn

*/

int

canonical_filename_eq (const char * a, const char * b)

{

  char * ca = lrealpath(a);

  char * cb = lrealpath(b);

  int res = filename_eq (ca, cb);

  free (ca);

  free (cb);

  return res;

}