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
39Return zero if the two file names @var{s1} and @var{s2} are equivalent.
40If not equivalent, the returned value is similar to what @code{strcmp}
41would return.  In other words, it returns a negative value if @var{s1}
42is less than @var{s2}, or a positive value if @var{s2} is greater than
43@var{s2}.
44
45This function does not normalize file names.  As a result, this function
46will treat filenames that are spelled differently as different even in
47the case when the two filenames point to the same underlying file.
48However, it does handle the fact that on DOS-like file systems, forward
49and backward slashes are equal.
50
51@end deftypefn
52
53*/
54
55int
56filename_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
96Return zero if the two file names @var{s1} and @var{s2} are equivalent
97in range @var{n}.
98If not equivalent, the returned value is similar to what @code{strncmp}
99would return.  In other words, it returns a negative value if @var{s1}
100is less than @var{s2}, or a positive value if @var{s2} is greater than
101@var{s2}.
102
103This function does not normalize file names.  As a result, this function
104will treat filenames that are spelled differently as different even in
105the case when the two filenames point to the same underlying file.
106However, it does handle the fact that on DOS-like file systems, forward
107and backward slashes are equal.
108
109@end deftypefn
110
111*/
112
113int
114filename_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
154Return the hash value for file name @var{s} that will be compared
155using filename_cmp.
156This function is for use with hashtab.c hash tables.
157
158@end deftypefn
159
160*/
161
162hashval_t
163filename_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
185Return non-zero if file names @var{s1} and @var{s2} are equivalent.
186This function is for use with hashtab.c hash tables.
187
188@end deftypefn
189
190*/
191
192int
193filename_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
203Return non-zero if file names @var{a} and @var{b} are equivalent.
204This 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
206underlying file are treated as being identical.
207
208@end deftypefn
209
210*/
211
212int
213canonical_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