[PATCH 3/3] ls: add statx-enabled variants of stat and lstat calls

[Jeff Layton]

* add wrapper functions for stat, lstat and stat_for_mode so that we
  can conditionally plug in statx-enabled variants
* add statx-enabled functions and set the request mask based on the
  output format and what values are needed
---
 src/ls.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 69 insertions(+), 4 deletions(-)

diff --git a/src/ls.c b/src/ls.c
index 8e5015e5ac12..3c12f63e595b 100644
--- a/src/ls.c
+++ b/src/ls.c
@@ -3166,6 +3166,71 @@ needs_quoting (char const* name)
   return *name != *test || strlen (name) != len;
 }
 
+#if USE_STATX
+static unsigned int
+calc_request_mask(void)
+{
+  unsigned int mask = STATX_MODE;
+
+  if (print_inode)
+    mask |= STATX_INO;
+  if (format == long_format) {
+    mask |= STATX_NLINK | STATX_SIZE;
+    if (print_owner || print_author)
+      mask |= STATX_UID;
+    if (print_group)
+      mask |= STATX_GID;
+  }
+  return mask;
+}
+
+static int
+do_statx (const char *name, struct stat *st, int flags, unsigned int mask)
+{
+  struct statx stx;
+  int ret = statx(AT_FDCWD, name, flags, mask, &stx);
+  if (ret >= 0)
+    statx_to_stat(&stx, st);
+  return ret;
+}
+
+static inline int
+do_stat(const char *name, struct stat *st)
+{
+  return do_statx(name, st, 0, calc_request_mask());
+}
+
+static int
+do_lstat (const char *name, struct stat *st)
+{
+  return do_statx(name, st, AT_SYMLINK_NOFOLLOW, calc_request_mask());
+}
+
+static int
+stat_for_mode(const char *name, struct stat *st)
+{
+  return do_statx(name, st, 0, STATX_MODE);
+}
+#else
+static inline int
+do_stat (const char *name, struct stat *st)
+{
+       return stat(name, st);
+}
+
+static inline int
+do_lstat (const char *name, struct stat *st)
+{
+       return lstat(name, st);
+}
+
+static int
+stat_for_mode(const char *name, struct stat *st)
+{
+  return do_stat(name, st);
+}
+#endif
+
 /* Add a file to the current table of files.
    Verify that the file exists, and print an error message if it does not.
    Return the number of blocks that the file occupies.  */
@@ -3264,7 +3329,7 @@ gobble_file (char const *name, enum filetype type, ino_t 
inode,
       switch (dereference)
         {
         case DEREF_ALWAYS:
-          err = stat (full_name, &f->stat);
+          err = do_stat (full_name, &f->stat);
           do_deref = true;
           break;
 
@@ -3273,7 +3338,7 @@ gobble_file (char const *name, enum filetype type, ino_t 
inode,
           if (command_line_arg)
             {
               bool need_lstat;
-              err = stat (full_name, &f->stat);
+              err = do_stat (full_name, &f->stat);
               do_deref = true;
 
               if (dereference == DEREF_COMMAND_LINE_ARGUMENTS)
@@ -3293,7 +3358,7 @@ gobble_file (char const *name, enum filetype type, ino_t 
inode,
           FALLTHROUGH;
 
         default: /* DEREF_NEVER */
-          err = lstat (full_name, &f->stat);
+          err = do_lstat (full_name, &f->stat);
           do_deref = false;
           break;
         }
@@ -3382,7 +3447,7 @@ gobble_file (char const *name, enum filetype type, ino_t 
inode,
              they won't be traced and when no indicator is needed.  */
           if (linkname
               && (file_type <= indicator_style || check_symlink_mode)
-              && stat (linkname, &linkstats) == 0)
+              && stat_for_mode(linkname, &linkstats) == 0)
             {
               f->linkok = true;
               f->linkmode = linkstats.st_mode;
-- 
2.21.0