libiberty/filename_cmp.c

   1 /* File name comparison routine.
   2
   3    Copyright (C) 2007-2021 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 }