Don't include <stdlib.h>, <unistd.h>, <fcntl.h>,

"gettext.h"; either no longer needed or are guaranteed by openat.h.
(_): Remove; no longer needed.
(openat): Renamed from rpl_openat; no need for rpl_openat
since openat.h renames openat for us.
Replace most of the body with a call to openat_permissive,
to avoid duplicate code.
Port to (probably hypothetical) environments were mode_t is
wider than int.
(openat_permissive): Require mode arg, so that we can check
types better.  Put it just after flags.  Change cwd failure
indicator from pointer-to-bool to pointer-to-errno-value.
All callers changed.
Invoke openat_save_fail and/or openat_restore_fail if
cwd_errno is null, so that openat can call us.
(openat_permissive, fdopendir, fstatat, unlinkat):
Simplify errno handling to avoid some duplicate code,
as it's OK to set errno on success.

1 files changed, 82 insertions, 147 deletions

diff --git a/lib/openat.c b/lib/openat.c
index 1c6d6d728..20c217d97 100644
--- a/lib/openat.c
+++ b/lib/openat.c
@@ -23,19 +23,13 @@
 
 #include "openat.h"
 
-#include <stdlib.h>
-#include <stdarg.h>
-#include <unistd.h>
-#include <errno.h>
-#include <fcntl.h>
-
 #include "dirname.h" /* solely for definition of IS_ABSOLUTE_FILE_NAME */
+#include "openat-priv.h"
 #include "save-cwd.h"
 
-#include "gettext.h"
-#define _(msgid) gettext (msgid)
-
-#include "openat-priv.h"
+#include <stdarg.h>
+#include <stddef.h>
+#include <errno.h>
 
 /* Replacement for Solaris' openat function.
    <http://www.google.com/search?q=openat+site:docs.sun.com>
@@ -46,61 +40,31 @@
    Otherwise, upon failure, set errno and return -1, as openat does.
    Upon successful completion, return a file descriptor.  */
 int
-rpl_openat (int fd, char const *file, int flags, ...)
+openat (int fd, char const *file, int flags, ...)
 {
-  struct saved_cwd saved_cwd;
-  int saved_errno;
-  int err;
   mode_t mode = 0;
 
   if (flags & O_CREAT)
     {
       va_list arg;
       va_start (arg, flags);
-      /* Use the promoted type (int), not mode_t, as second argument.  */
-      mode = (mode_t) va_arg (arg, int);
-      va_end (arg);
-    }
-
-  if (fd == AT_FDCWD || IS_ABSOLUTE_FILE_NAME (file))
-    return open (file, flags, mode);
-
-  {
-    char *proc_file;
-    BUILD_PROC_NAME (proc_file, fd, file);
-    err = open (proc_file, flags, mode);
-    /* If the syscall succeeds, or if it fails with an unexpected
-       errno value, then return right away.  Otherwise, fall through
-       and resort to using save_cwd/restore_cwd.  */
-    if (0 <= err || ! EXPECTED_ERRNO (errno))
-      return err;
-  }
 
-  if (save_cwd (&saved_cwd) != 0)
-    openat_save_fail (errno);
+      /* If mode_t is narrower than int, use the promoted type (int),
+         not mode_t.  Use sizeof to guess whether mode_t is nerrower;
+         we don't know of any practical counterexamples.  */
+      if (sizeof (mode_t) < sizeof (int))
+	mode = va_arg (arg, int);
+      else
+	mode = va_arg (arg, mode_t);
 
-  if (fchdir (fd) != 0)
-    {
-      saved_errno = errno;
-      free_cwd (&saved_cwd);
-      errno = saved_errno;
-      return -1;
+      va_end (arg);
     }
 
-  err = open (file, flags, mode);
-  saved_errno = (err < 0 ? errno : 0);
-
-  if (restore_cwd (&saved_cwd) != 0)
-    openat_restore_fail (errno);
-
-  free_cwd (&saved_cwd);
-
-  if (saved_errno)
-    errno = saved_errno;
-  return err;
+  return openat_permissive (fd, file, flags, mode, NULL);
 }
 
-/* Like openat above, but set *RESTORE_FAILED if unable to save
+/* Like openat (FD, FILE, FLAGS, MODE), but if CWD_ERRNO is
+   nonnull, set *CWD_ERRNO to an errno value if unable to save
    or restore the initial working directory.  This is needed only
    the first time remove.c's remove_dir opens a command-line
    directory argument.
@@ -111,23 +75,13 @@ rpl_openat (int fd, char const *file, int flags, ...)
    in that case.  */
 
 int
-openat_permissive (int fd, char const *file, int flags,
-		   bool *cwd_restore_failed, ...)
+openat_permissive (int fd, char const *file, int flags, mode_t mode,
+		   int *cwd_errno)
 {
   struct saved_cwd saved_cwd;
   int saved_errno;
-  int save_restore_errno = 0;
   int err;
-  mode_t mode = 0;
-
-  if (flags & O_CREAT)
-    {
-      va_list arg;
-      va_start (arg, cwd_restore_failed);
-      /* Use the promoted type (int), not mode_t, as second argument.  */
-      mode = (mode_t) va_arg (arg, int);
-      va_end (arg);
-    }
+  bool save_ok;
 
   if (fd == AT_FDCWD || IS_ABSOLUTE_FILE_NAME (file))
     return open (file, flags, mode);
@@ -143,37 +97,31 @@ openat_permissive (int fd, char const *file, int flags,
       return err;
   }
 
-  if (save_cwd (&saved_cwd) != 0)
+  save_ok = (save_cwd (&saved_cwd) == 0);
+  if (! save_ok)
     {
-      *cwd_restore_failed = true;
-      save_restore_errno = errno;
+      if (! cwd_errno)
+	openat_save_fail (errno);
+      *cwd_errno = errno;
     }
 
-  if (fchdir (fd) != 0)
-    {
-      saved_errno = errno;
-      free_cwd (&saved_cwd);
-      errno = saved_errno;
-      return -1;
-    }
-
-  err = open (file, flags, mode);
-  saved_errno = (err < 0 ? errno : 0);
+  err = fchdir (fd);
+  saved_errno = errno;
 
-  if ( ! *cwd_restore_failed && restore_cwd (&saved_cwd) != 0)
+  if (! err)
     {
-      *cwd_restore_failed = true;
-      save_restore_errno = errno;
+      err = open (file, flags, mode);
+      saved_errno = errno;
+      if (save_ok && restore_cwd (&saved_cwd) != 0)
+	{
+	  if (! cwd_errno)
+	    openat_restore_fail (errno);
+	  *cwd_errno = errno;
+	}
     }
 
-  if ( ! *cwd_restore_failed)
-    free_cwd (&saved_cwd);
-
-  if (saved_errno)
-    errno = saved_errno;
-  else if (save_restore_errno)
-    errno = save_restore_errno;
-
+  free_cwd (&saved_cwd);
+  errno = saved_errno;
   return err;
 }
 
@@ -198,43 +146,38 @@ fdopendir (int fd)
   int saved_errno;
   DIR *dir;
 
-  {
-    char *proc_file;
-    BUILD_PROC_NAME (proc_file, fd, ".");
-    dir = opendir (proc_file);
-    saved_errno = (dir == NULL ? errno : 0);
-    /* If the syscall succeeds, or if it fails with an unexpected
-       errno value, then return right away.  Otherwise, fall through
-       and resort to using save_cwd/restore_cwd.  */
-    if (dir != NULL || ! EXPECTED_ERRNO (errno))
-      goto close_and_return;
-  }
+  char *proc_file;
+  BUILD_PROC_NAME (proc_file, fd, ".");
+  dir = opendir (proc_file);
+  saved_errno = errno;
 
-  if (save_cwd (&saved_cwd) != 0)
-    openat_save_fail (errno);
-
-  if (fchdir (fd) != 0)
+  /* If the syscall fails with an expected errno value, resort to
+     save_cwd/restore_cwd.  */
+  if (! dir && EXPECTED_ERRNO (saved_errno))
     {
-      saved_errno = errno;
+      if (save_cwd (&saved_cwd) != 0)
+	openat_save_fail (errno);
+
+      if (fchdir (fd) != 0)
+	{
+	  dir = NULL;
+	  saved_errno = errno;
+	}
+      else
+	{
+	  dir = opendir (".");
+	  saved_errno = errno;
+
+	  if (restore_cwd (&saved_cwd) != 0)
+	    openat_restore_fail (errno);
+	}
+
       free_cwd (&saved_cwd);
-      errno = saved_errno;
-      return NULL;
     }
 
-  dir = opendir (".");
-  saved_errno = (dir == NULL ? errno : 0);
-
-  if (restore_cwd (&saved_cwd) != 0)
-    openat_restore_fail (errno);
-
-  free_cwd (&saved_cwd);
-
- close_and_return:;
   if (dir)
     close (fd);
-
-  if (saved_errno)
-    errno = saved_errno;
+  errno = saved_errno;
   return dir;
 }
 
@@ -275,26 +218,22 @@ fstatat (int fd, char const *file, struct stat *st, int flag)
   if (save_cwd (&saved_cwd) != 0)
     openat_save_fail (errno);
 
-  if (fchdir (fd) != 0)
+  err = fchdir (fd);
+  saved_errno = errno;
+
+  if (! err)
     {
+      err = (flag == AT_SYMLINK_NOFOLLOW
+	     ? lstat (file, st)
+	     : stat (file, st));
       saved_errno = errno;
-      free_cwd (&saved_cwd);
-      errno = saved_errno;
-      return -1;
-    }
-
-  err = (flag == AT_SYMLINK_NOFOLLOW
-	 ? lstat (file, st)
-	 : stat (file, st));
-  saved_errno = (err < 0 ? errno : 0);
 
-  if (restore_cwd (&saved_cwd) != 0)
-    openat_restore_fail (errno);
+      if (restore_cwd (&saved_cwd) != 0)
+	openat_restore_fail (errno);
+    }
 
   free_cwd (&saved_cwd);
-
-  if (saved_errno)
-    errno = saved_errno;
+  errno = saved_errno;
   return err;
 }
 
@@ -329,23 +268,19 @@ unlinkat (int fd, char const *file, int flag)
   if (save_cwd (&saved_cwd) != 0)
     openat_save_fail (errno);
 
-  if (fchdir (fd) != 0)
+  err = fchdir (fd);
+  saved_errno = errno;
+
+  if (! err)
     {
+      err = (flag == AT_REMOVEDIR ? rmdir (file) : unlink (file));
       saved_errno = errno;
-      free_cwd (&saved_cwd);
-      errno = saved_errno;
-      return -1;
-    }
-
-  err = (flag == AT_REMOVEDIR ? rmdir (file) : unlink (file));
-  saved_errno = (err < 0 ? errno : 0);
 
-  if (restore_cwd (&saved_cwd) != 0)
-    openat_restore_fail (errno);
+      if (restore_cwd (&saved_cwd) != 0)
+	openat_restore_fail (errno);
+    }
 
   free_cwd (&saved_cwd);
-
-  if (saved_errno)
-    errno = saved_errno;
+  errno = saved_errno;
   return err;
 }