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      1 /* Work around platform bugs in stat.
      2    Copyright (C) 2009-2012 Free Software Foundation, Inc.
      3 
      4    This program is free software: you can redistribute it and/or modify
      5    it under the terms of the GNU General Public License as published by
      6    the Free Software Foundation; either version 3 of the License, or
      7    (at your option) any later version.
      8 
      9    This program is distributed in the hope that it will be useful,
     10    but WITHOUT ANY WARRANTY; without even the implied warranty of
     11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     12    GNU General Public License for more details.
     13 
     14    You should have received a copy of the GNU General Public License
     15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
     16 
     17 /* written by Eric Blake */
     18 
     19 /* If the user's config.h happens to include <sys/stat.h>, let it include only
     20    the system's <sys/stat.h> here, so that orig_stat doesn't recurse to
     21    rpl_stat.  */
     22 #define __need_system_sys_stat_h
     23 #include <config.h>
     24 
     25 /* Get the original definition of stat.  It might be defined as a macro.  */
     26 #include <sys/types.h>
     27 #include <sys/stat.h>
     28 #undef __need_system_sys_stat_h
     29 
     30 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
     31 # if _GL_WINDOWS_64_BIT_ST_SIZE
     32 #  undef stat /* avoid warning on mingw64 with _FILE_OFFSET_BITS=64 */
     33 #  define stat _stati64
     34 #  define REPLACE_FUNC_STAT_DIR 1
     35 #  undef REPLACE_FUNC_STAT_FILE
     36 # elif REPLACE_FUNC_STAT_FILE
     37 /* mingw64 has a broken stat() function, based on _stat(), in libmingwex.a.
     38    Bypass it.  */
     39 #  define stat _stat
     40 #  define REPLACE_FUNC_STAT_DIR 1
     41 #  undef REPLACE_FUNC_STAT_FILE
     42 # endif
     43 #endif
     44 
     45 static int
     46 orig_stat (const char *filename, struct stat *buf)
     47 {
     48   return stat (filename, buf);
     49 }
     50 
     51 /* Specification.  */
     52 /* Write "sys/stat.h" here, not <sys/stat.h>, otherwise OSF/1 5.1 DTK cc
     53    eliminates this include because of the preliminary #include <sys/stat.h>
     54    above.  */
     55 #include "sys/stat.h"
     56 
     57 #include <errno.h>
     58 #include <limits.h>
     59 #include <stdbool.h>
     60 #include <string.h>
     61 #include "dosname.h"
     62 #include "verify.h"
     63 
     64 #if REPLACE_FUNC_STAT_DIR
     65 # include "pathmax.h"
     66   /* The only known systems where REPLACE_FUNC_STAT_DIR is needed also
     67      have a constant PATH_MAX.  */
     68 # ifndef PATH_MAX
     69 #  error "Please port this replacement to your platform"
     70 # endif
     71 #endif
     72 
     73 /* Store information about NAME into ST.  Work around bugs with
     74    trailing slashes.  Mingw has other bugs (such as st_ino always
     75    being 0 on success) which this wrapper does not work around.  But
     76    at least this implementation provides the ability to emulate fchdir
     77    correctly.  */
     78 
     79 int
     80 rpl_stat (char const *name, struct stat *st)
     81 {
     82   int result = orig_stat (name, st);
     83 #if REPLACE_FUNC_STAT_FILE
     84   /* Solaris 9 mistakenly succeeds when given a non-directory with a
     85      trailing slash.  */
     86   if (result == 0 && !S_ISDIR (st->st_mode))
     87     {
     88       size_t len = strlen (name);
     89       if (ISSLASH (name[len - 1]))
     90         {
     91           errno = ENOTDIR;
     92           return -1;
     93         }
     94     }
     95 #endif /* REPLACE_FUNC_STAT_FILE */
     96 #if REPLACE_FUNC_STAT_DIR
     97 
     98   if (result == -1 && errno == ENOENT)
     99     {
    100       /* Due to mingw's oddities, there are some directories (like
    101          c:\) where stat() only succeeds with a trailing slash, and
    102          other directories (like c:\windows) where stat() only
    103          succeeds without a trailing slash.  But we want the two to be
    104          synonymous, since chdir() manages either style.  Likewise, Mingw also
    105          reports ENOENT for names longer than PATH_MAX, when we want
    106          ENAMETOOLONG, and for stat("file/"), when we want ENOTDIR.
    107          Fortunately, mingw PATH_MAX is small enough for stack
    108          allocation.  */
    109       char fixed_name[PATH_MAX + 1] = {0};
    110       size_t len = strlen (name);
    111       bool check_dir = false;
    112       verify (PATH_MAX <= 4096);
    113       if (PATH_MAX <= len)
    114         errno = ENAMETOOLONG;
    115       else if (len)
    116         {
    117           strcpy (fixed_name, name);
    118           if (ISSLASH (fixed_name[len - 1]))
    119             {
    120               check_dir = true;
    121               while (len && ISSLASH (fixed_name[len - 1]))
    122                 fixed_name[--len] = '\0';
    123               if (!len)
    124                 fixed_name[0] = '/';
    125             }
    126           else
    127             fixed_name[len++] = '/';
    128           result = orig_stat (fixed_name, st);
    129           if (result == 0 && check_dir && !S_ISDIR (st->st_mode))
    130             {
    131               result = -1;
    132               errno = ENOTDIR;
    133             }
    134         }
    135     }
    136 #endif /* REPLACE_FUNC_STAT_DIR */
    137   return result;
    138 }
    139