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      1 /* File name comparison routine.
      2 
      3    Copyright (C) 2007 Free Software Foundation, Inc.
      4 
      5    This program is free software; you can redistribute it and/or modify
      6    it under the terms of the GNU General Public License as published by
      7    the Free Software Foundation; either version 2, or (at your option)
      8    any later version.
      9 
     10    This program is distributed in the hope that it will be useful,
     11    but WITHOUT ANY WARRANTY; without even the implied warranty of
     12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     13    GNU General Public License for more details.
     14 
     15    You should have received a copy of the GNU General Public License
     16    along with this program; if not, write to the Free Software Foundation,
     17    Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
     18 
     19 #ifdef HAVE_CONFIG_H
     20 #include "config.h"
     21 #endif
     22 
     23 #ifdef HAVE_STRING_H
     24 #include <string.h>
     25 #endif
     26 
     27 #ifdef HAVE_STDLIB_H
     28 #include <stdlib.h>
     29 #endif
     30 
     31 #include "filenames.h"
     32 #include "safe-ctype.h"
     33 #include "libiberty.h"
     34 
     35 /*
     36 
     37 @deftypefn Extension int filename_cmp (const char *@var{s1}, const char *@var{s2})
     38 
     39 Return zero if the two file names @var{s1} and @var{s2} are equivalent.
     40 If not equivalent, the returned value is similar to what @code{strcmp}
     41 would return.  In other words, it returns a negative value if @var{s1}
     42 is less than @var{s2}, or a positive value if @var{s2} is greater than
     43 @var{s2}.
     44 
     45 This function does not normalize file names.  As a result, this function
     46 will treat filenames that are spelled differently as different even in
     47 the case when the two filenames point to the same underlying file.
     48 However, it does handle the fact that on DOS-like file systems, forward
     49 and backward slashes are equal.
     50 
     51 @end deftypefn
     52 
     53 */
     54 
     55 int
     56 filename_cmp (const char *s1, const char *s2)
     57 {
     58 #if !defined(HAVE_DOS_BASED_FILE_SYSTEM) \
     59     && !defined(HAVE_CASE_INSENSITIVE_FILE_SYSTEM)
     60   return strcmp(s1, s2);
     61 #else
     62   for (;;)
     63     {
     64       int c1 = *s1;
     65       int c2 = *s2;
     66 
     67 #if defined (HAVE_CASE_INSENSITIVE_FILE_SYSTEM)
     68       c1 = TOLOWER (c1);
     69       c2 = TOLOWER (c2);
     70 #endif
     71 
     72 #if defined (HAVE_DOS_BASED_FILE_SYSTEM)
     73       /* On DOS-based file systems, the '/' and the '\' are equivalent.  */
     74       if (c1 == '/')
     75         c1 = '\\';
     76       if (c2 == '/')
     77         c2 = '\\';
     78 #endif
     79 
     80       if (c1 != c2)
     81         return (c1 - c2);
     82 
     83       if (c1 == '\0')
     84         return 0;
     85 
     86       s1++;
     87       s2++;
     88     }
     89 #endif
     90 }
     91 
     92 /*
     93 
     94 @deftypefn Extension int filename_ncmp (const char *@var{s1}, const char *@var{s2}, size_t @var{n})
     95 
     96 Return zero if the two file names @var{s1} and @var{s2} are equivalent
     97 in range @var{n}.
     98 If not equivalent, the returned value is similar to what @code{strncmp}
     99 would return.  In other words, it returns a negative value if @var{s1}
    100 is less than @var{s2}, or a positive value if @var{s2} is greater than
    101 @var{s2}.
    102 
    103 This function does not normalize file names.  As a result, this function
    104 will treat filenames that are spelled differently as different even in
    105 the case when the two filenames point to the same underlying file.
    106 However, it does handle the fact that on DOS-like file systems, forward
    107 and backward slashes are equal.
    108 
    109 @end deftypefn
    110 
    111 */
    112 
    113 int
    114 filename_ncmp (const char *s1, const char *s2, size_t n)
    115 {
    116 #if !defined(HAVE_DOS_BASED_FILE_SYSTEM) \
    117     && !defined(HAVE_CASE_INSENSITIVE_FILE_SYSTEM)
    118   return strncmp(s1, s2, n);
    119 #else
    120   if (!n)
    121     return 0;
    122   for (; n > 0; --n)
    123   {
    124       int c1 = *s1;
    125       int c2 = *s2;
    126 
    127 #if defined (HAVE_CASE_INSENSITIVE_FILE_SYSTEM)
    128       c1 = TOLOWER (c1);
    129       c2 = TOLOWER (c2);
    130 #endif
    131 
    132 #if defined (HAVE_DOS_BASED_FILE_SYSTEM)
    133       /* On DOS-based file systems, the '/' and the '\' are equivalent.  */
    134       if (c1 == '/')
    135         c1 = '\\';
    136       if (c2 == '/')
    137         c2 = '\\';
    138 #endif
    139 
    140       if (c1 == '\0' || c1 != c2)
    141         return (c1 - c2);
    142 
    143       s1++;
    144       s2++;
    145   }
    146   return 0;
    147 #endif
    148 }
    149 
    150 /*
    151 
    152 @deftypefn Extension hashval_t filename_hash (const void *@var{s})
    153 
    154 Return the hash value for file name @var{s} that will be compared
    155 using filename_cmp.
    156 This function is for use with hashtab.c hash tables.
    157 
    158 @end deftypefn
    159 
    160 */
    161 
    162 hashval_t
    163 filename_hash (const void *s)
    164 {
    165   /* The cast is for -Wc++-compat.  */
    166   const unsigned char *str = (const unsigned char *) s;
    167   hashval_t r = 0;
    168   unsigned char c;
    169 
    170   while ((c = *str++) != 0)
    171     {
    172       if (c == '\\')
    173 	c = '/';
    174       c = TOLOWER (c);
    175       r = r * 67 + c - 113;
    176     }
    177 
    178   return r;
    179 }
    180 
    181 /*
    182 
    183 @deftypefn Extension int filename_eq (const void *@var{s1}, const void *@var{s2})
    184 
    185 Return non-zero if file names @var{s1} and @var{s2} are equivalent.
    186 This function is for use with hashtab.c hash tables.
    187 
    188 @end deftypefn
    189 
    190 */
    191 
    192 int
    193 filename_eq (const void *s1, const void *s2)
    194 {
    195   /* The casts are for -Wc++-compat.  */
    196   return filename_cmp ((const char *) s1, (const char *) s2) == 0;
    197 }
    198 
    199 /*
    200 
    201 @deftypefn Extension int canonical_filename_eq (const char *@var{a}, const char *@var{b})
    202 
    203 Return non-zero if file names @var{a} and @var{b} are equivalent.
    204 This function compares the canonical versions of the filenames as returned by
    205 @code{lrealpath()}, so that so that different file names pointing to the same
    206 underlying file are treated as being identical.
    207 
    208 @end deftypefn
    209 
    210 */
    211 
    212 int
    213 canonical_filename_eq (const char * a, const char * b)
    214 {
    215   char * ca = lrealpath(a);
    216   char * cb = lrealpath(b);
    217   int res = filename_eq (ca, cb);
    218   free (ca);
    219   free (cb);
    220   return res;
    221 }
    222