Sync with the latest Gnulib code (d27c820595)

1 files changed, 440 insertions, 0 deletions

diff --git a/gl/stat.c b/gl/stat.c
new file mode 100644
index 00000000..574489ac
--- /dev/null
+++ b/gl/stat.c
@@ -0,0 +1,440 @@
+/* Work around platform bugs in stat.
+   Copyright (C) 2009-2022 Free Software Foundation, Inc.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   This file 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 Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Eric Blake and Bruno Haible.  */
+
+/* If the user's config.h happens to include <sys/stat.h>, let it include only
+   the system's <sys/stat.h> here, so that orig_stat doesn't recurse to
+   rpl_stat.  */
+#define __need_system_sys_stat_h
+#include <config.h>
+
+/* Get the original definition of stat.  It might be defined as a macro.  */
+#include <sys/types.h>
+#include <sys/stat.h>
+#undef __need_system_sys_stat_h
+
+#if defined _WIN32 && ! defined __CYGWIN__
+# define WINDOWS_NATIVE
+#endif
+
+#if !defined WINDOWS_NATIVE
+
+static int
+orig_stat (const char *filename, struct stat *buf)
+{
+  return stat (filename, buf);
+}
+
+#endif
+
+/* Specification.  */
+#ifdef __osf__
+/* Write "sys/stat.h" here, not <sys/stat.h>, otherwise OSF/1 5.1 DTK cc
+   eliminates this include because of the preliminary #include <sys/stat.h>
+   above.  */
+# include "sys/stat.h"
+#else
+# include <sys/stat.h>
+#endif
+
+#include "stat-time.h"
+
+#include <errno.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <string.h>
+#include "filename.h"
+#include "malloca.h"
+#include "verify.h"
+
+#ifdef WINDOWS_NATIVE
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+# include "stat-w32.h"
+/* Don't assume that UNICODE is not defined.  */
+# undef WIN32_FIND_DATA
+# define WIN32_FIND_DATA WIN32_FIND_DATAA
+# undef CreateFile
+# define CreateFile CreateFileA
+# undef FindFirstFile
+# define FindFirstFile FindFirstFileA
+#endif
+
+#ifdef WINDOWS_NATIVE
+/* Return TRUE if the given file name denotes an UNC root.  */
+static BOOL
+is_unc_root (const char *rname)
+{
+  /* Test whether it has the syntax '\\server\share'.  */
+  if (ISSLASH (rname[0]) && ISSLASH (rname[1]))
+    {
+      /* It starts with two slashes.  Find the next slash.  */
+      const char *p = rname + 2;
+      const char *q = p;
+      while (*q != '\0' && !ISSLASH (*q))
+        q++;
+      if (q > p && *q != '\0')
+        {
+          /* Found the next slash at q.  */
+          q++;
+          const char *r = q;
+          while (*r != '\0' && !ISSLASH (*r))
+            r++;
+          if (r > q && *r == '\0')
+            return TRUE;
+        }
+    }
+  return FALSE;
+}
+#endif
+
+/* Store information about NAME into ST.  Work around bugs with
+   trailing slashes.  Mingw has other bugs (such as st_ino always
+   being 0 on success) which this wrapper does not work around.  But
+   at least this implementation provides the ability to emulate fchdir
+   correctly.  */
+
+int
+rpl_stat (char const *name, struct stat *buf)
+{
+#ifdef WINDOWS_NATIVE
+  /* Fill the fields ourselves, because the original stat function returns
+     values for st_atime, st_mtime, st_ctime that depend on the current time
+     zone.  See
+     <https://lists.gnu.org/r/bug-gnulib/2017-04/msg00134.html>  */
+  /* XXX Should we convert to wchar_t* and prepend '\\?\', in order to work
+     around length limitations
+     <https://docs.microsoft.com/en-us/windows/desktop/FileIO/naming-a-file> ?  */
+
+  /* POSIX <https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13>
+     specifies: "More than two leading <slash> characters shall be treated as
+     a single <slash> character."  */
+  if (ISSLASH (name[0]) && ISSLASH (name[1]) && ISSLASH (name[2]))
+    {
+      name += 2;
+      while (ISSLASH (name[1]))
+        name++;
+    }
+
+  size_t len = strlen (name);
+  size_t drive_prefix_len = (HAS_DEVICE (name) ? 2 : 0);
+
+  /* Remove trailing slashes (except the very first one, at position
+     drive_prefix_len), but remember their presence.  */
+  size_t rlen;
+  bool check_dir = false;
+
+  rlen = len;
+  while (rlen > drive_prefix_len && ISSLASH (name[rlen-1]))
+    {
+      check_dir = true;
+      if (rlen == drive_prefix_len + 1)
+        break;
+      rlen--;
+    }
+
+  /* Handle '' and 'C:'.  */
+  if (!check_dir && rlen == drive_prefix_len)
+    {
+      errno = ENOENT;
+      return -1;
+    }
+
+  /* Handle '\\'.  */
+  if (rlen == 1 && ISSLASH (name[0]) && len >= 2)
+    {
+      errno = ENOENT;
+      return -1;
+    }
+
+  const char *rname;
+  char *malloca_rname;
+  if (rlen == len)
+    {
+      rname = name;
+      malloca_rname = NULL;
+    }
+  else
+    {
+      malloca_rname = malloca (rlen + 1);
+      if (malloca_rname == NULL)
+        {
+          errno = ENOMEM;
+          return -1;
+        }
+      memcpy (malloca_rname, name, rlen);
+      malloca_rname[rlen] = '\0';
+      rname = malloca_rname;
+    }
+
+  /* There are two ways to get at the requested information:
+       - by scanning the parent directory and examining the relevant
+         directory entry,
+       - by opening the file directly.
+     The first approach fails for root directories (e.g. 'C:\') and
+     UNC root directories (e.g. '\\server\share').
+     The second approach fails for some system files (e.g. 'C:\pagefile.sys'
+     and 'C:\hiberfil.sys'): ERROR_SHARING_VIOLATION.
+     The second approach gives more information (in particular, correct
+     st_dev, st_ino, st_nlink fields).
+     So we use the second approach and, as a fallback except for root and
+     UNC root directories, also the first approach.  */
+  {
+    int ret;
+
+    {
+      /* Approach based on the file.  */
+
+      /* Open a handle to the file.
+         CreateFile
+         <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-createfilea>
+         <https://docs.microsoft.com/en-us/windows/desktop/FileIO/creating-and-opening-files>  */
+      HANDLE h =
+        CreateFile (rname,
+                    FILE_READ_ATTRIBUTES,
+                    FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
+                    NULL,
+                    OPEN_EXISTING,
+                    /* FILE_FLAG_POSIX_SEMANTICS (treat file names that differ only
+                       in case as different) makes sense only when applied to *all*
+                       filesystem operations.  */
+                    FILE_FLAG_BACKUP_SEMANTICS /* | FILE_FLAG_POSIX_SEMANTICS */,
+                    NULL);
+      if (h != INVALID_HANDLE_VALUE)
+        {
+          ret = _gl_fstat_by_handle (h, rname, buf);
+          CloseHandle (h);
+          goto done;
+        }
+    }
+
+    /* Test for root and UNC root directories.  */
+    if ((rlen == drive_prefix_len + 1 && ISSLASH (rname[drive_prefix_len]))
+        || is_unc_root (rname))
+      goto failed;
+
+    /* Fallback.  */
+    {
+      /* Approach based on the directory entry.  */
+
+      if (strchr (rname, '?') != NULL || strchr (rname, '*') != NULL)
+        {
+          /* Other Windows API functions would fail with error
+             ERROR_INVALID_NAME.  */
+          if (malloca_rname != NULL)
+            freea (malloca_rname);
+          errno = ENOENT;
+          return -1;
+        }
+
+      /* Get the details about the directory entry.  This can be done through
+         FindFirstFile
+         <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-findfirstfilea>
+         <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ns-minwinbase-_win32_find_dataa>
+         or through
+         FindFirstFileEx with argument FindExInfoBasic
+         <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-findfirstfileexa>
+         <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ne-minwinbase-findex_info_levels>
+         <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ns-minwinbase-_win32_find_dataa>  */
+      WIN32_FIND_DATA info;
+      HANDLE h = FindFirstFile (rname, &info);
+      if (h == INVALID_HANDLE_VALUE)
+        goto failed;
+
+      /* Test for error conditions before starting to fill *buf.  */
+      if (sizeof (buf->st_size) <= 4 && info.nFileSizeHigh > 0)
+        {
+          FindClose (h);
+          if (malloca_rname != NULL)
+            freea (malloca_rname);
+          errno = EOVERFLOW;
+          return -1;
+        }
+
+# if _GL_WINDOWS_STAT_INODES
+      buf->st_dev = 0;
+#  if _GL_WINDOWS_STAT_INODES == 2
+      buf->st_ino._gl_ino[0] = buf->st_ino._gl_ino[1] = 0;
+#  else /* _GL_WINDOWS_STAT_INODES == 1 */
+      buf->st_ino = 0;
+#  endif
+# else
+      /* st_ino is not wide enough for identifying a file on a device.
+         Without st_ino, st_dev is pointless.  */
+      buf->st_dev = 0;
+      buf->st_ino = 0;
+# endif
+
+      /* st_mode.  */
+      unsigned int mode =
+        /* XXX How to handle FILE_ATTRIBUTE_REPARSE_POINT ?  */
+        ((info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ? _S_IFDIR | S_IEXEC_UGO : _S_IFREG)
+        | S_IREAD_UGO
+        | ((info.dwFileAttributes & FILE_ATTRIBUTE_READONLY) ? 0 : S_IWRITE_UGO);
+      if (!(info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY))
+        {
+          /* Determine whether the file is executable by looking at the file
+             name suffix.  */
+          if (info.nFileSizeHigh > 0 || info.nFileSizeLow > 0)
+            {
+              const char *last_dot = NULL;
+              const char *p;
+              for (p = info.cFileName; *p != '\0'; p++)
+                if (*p == '.')
+                  last_dot = p;
+              if (last_dot != NULL)
+                {
+                  const char *suffix = last_dot + 1;
+                  if (_stricmp (suffix, "exe") == 0
+                      || _stricmp (suffix, "bat") == 0
+                      || _stricmp (suffix, "cmd") == 0
+                      || _stricmp (suffix, "com") == 0)
+                    mode |= S_IEXEC_UGO;
+                }
+            }
+        }
+      buf->st_mode = mode;
+
+      /* st_nlink.  Ignore hard links here.  */
+      buf->st_nlink = 1;
+
+      /* There's no easy way to map the Windows SID concept to an integer.  */
+      buf->st_uid = 0;
+      buf->st_gid = 0;
+
+      /* st_rdev is irrelevant for normal files and directories.  */
+      buf->st_rdev = 0;
+
+      /* st_size.  */
+      if (sizeof (buf->st_size) <= 4)
+        /* Range check already done above.  */
+        buf->st_size = info.nFileSizeLow;
+      else
+        buf->st_size = ((long long) info.nFileSizeHigh << 32) | (long long) info.nFileSizeLow;
+
+      /* st_atime, st_mtime, st_ctime.  */
+# if _GL_WINDOWS_STAT_TIMESPEC
+      buf->st_atim = _gl_convert_FILETIME_to_timespec (&info.ftLastAccessTime);
+      buf->st_mtim = _gl_convert_FILETIME_to_timespec (&info.ftLastWriteTime);
+      buf->st_ctim = _gl_convert_FILETIME_to_timespec (&info.ftCreationTime);
+# else
+      buf->st_atime = _gl_convert_FILETIME_to_POSIX (&info.ftLastAccessTime);
+      buf->st_mtime = _gl_convert_FILETIME_to_POSIX (&info.ftLastWriteTime);
+      buf->st_ctime = _gl_convert_FILETIME_to_POSIX (&info.ftCreationTime);
+# endif
+
+      FindClose (h);
+
+      ret = 0;
+    }
+
+   done:
+    if (ret >= 0 && check_dir && !S_ISDIR (buf->st_mode))
+      {
+        errno = ENOTDIR;
+        ret = -1;
+      }
+    if (malloca_rname != NULL)
+      {
+        int saved_errno = errno;
+        freea (malloca_rname);
+        errno = saved_errno;
+      }
+    return ret;
+  }
+
+ failed:
+  {
+    DWORD error = GetLastError ();
+    #if 0
+    fprintf (stderr, "rpl_stat error 0x%x\n", (unsigned int) error);
+    #endif
+
+    if (malloca_rname != NULL)
+      freea (malloca_rname);
+
+    switch (error)
+      {
+      /* Some of these errors probably cannot happen with the specific flags
+         that we pass to CreateFile.  But who knows...  */
+      case ERROR_FILE_NOT_FOUND: /* The last component of rname does not exist.  */
+      case ERROR_PATH_NOT_FOUND: /* Some directory component in rname does not exist.  */
+      case ERROR_BAD_PATHNAME:   /* rname is such as '\\server'.  */
+      case ERROR_BAD_NET_NAME:   /* rname is such as '\\server\nonexistentshare'.  */
+      case ERROR_INVALID_NAME:   /* rname contains wildcards, misplaced colon, etc.  */
+      case ERROR_DIRECTORY:
+        errno = ENOENT;
+        break;
+
+      case ERROR_ACCESS_DENIED:  /* rname is such as 'C:\System Volume Information\foo'.  */
+      case ERROR_SHARING_VIOLATION: /* rname is such as 'C:\pagefile.sys' (second approach only).  */
+                                    /* XXX map to EACCES or EPERM? */
+        errno = EACCES;
+        break;
+
+      case ERROR_OUTOFMEMORY:
+        errno = ENOMEM;
+        break;
+
+      case ERROR_WRITE_PROTECT:
+        errno = EROFS;
+        break;
+
+      case ERROR_WRITE_FAULT:
+      case ERROR_READ_FAULT:
+      case ERROR_GEN_FAILURE:
+        errno = EIO;
+        break;
+
+      case ERROR_BUFFER_OVERFLOW:
+      case ERROR_FILENAME_EXCED_RANGE:
+        errno = ENAMETOOLONG;
+        break;
+
+      case ERROR_DELETE_PENDING: /* XXX map to EACCES or EPERM? */
+        errno = EPERM;
+        break;
+
+      default:
+        errno = EINVAL;
+        break;
+      }
+
+    return -1;
+  }
+#else
+  int result = orig_stat (name, buf);
+  if (result == 0)
+    {
+# if REPLACE_FUNC_STAT_FILE
+      /* Solaris 9 mistakenly succeeds when given a non-directory with a
+         trailing slash.  */
+      if (!S_ISDIR (buf->st_mode))
+        {
+          size_t len = strlen (name);
+          if (ISSLASH (name[len - 1]))
+            {
+              errno = ENOTDIR;
+              return -1;
+            }
+        }
+# endif /* REPLACE_FUNC_STAT_FILE */
+      result = stat_time_normalize (result, buf);
+    }
+  return result;
+#endif
+}