dirname: split into dirname-lgpl

dirname.h is proving quite useful from multiple LGPL modules,
given the number of trailing slash bugs fixed in syscalls;
only the calls to xalloc_die need to remain GPL.

* modules/dirname-lgpl: New module.
* modules/dirname (Files): Move library-safe files into
dirname-lgpl.
(Depends-on): Add dirname-lgpl.
(configure.ac): Declare witness.
* modules/double-slash-root (License): Relax license.
* lib/dirname.h (base_name, dir_name): Only declare when using GPL
module.
* lib/dirname.c (dir_len, mdir_name): Move...
* lib/dirname-lgpl.c: ...into new file.
* lib/basename.c (last_component, base_len): Move...
* lib/basename-lgpl.c: ...into new file.
* m4/dirname.m4 (gl_DIRNAME_LGPL): New macro.
(gl_DIRNAME): Use it.
* MODULES.html.sh (Enhancements for POSIX:2008 functions):
Mention new module.
* modules/dirname-tests (Depends-on): Add progname.
* tests/test-dirname.c (program_name): Delete.

Signed-off-by: Eric Blake <ebb9@byu.net>

1 files changed, 75 insertions, 0 deletions

diff --git a/lib/basename-lgpl.c b/lib/basename-lgpl.c
new file mode 100644
index 0000000000..444f042650
--- /dev/null
+++ b/lib/basename-lgpl.c
@@ -0,0 +1,75 @@
+/* basename.c -- return the last element in a file name
+
+   Copyright (C) 1990, 1998, 1999, 2000, 2001, 2003, 2004, 2005, 2006,
+   2009 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+#include "dirname.h"
+
+#include <string.h>
+
+/* Return the address of the last file name component of NAME.  If
+   NAME has no relative file name components because it is a file
+   system root, return the empty string.  */
+
+char *
+last_component (char const *name)
+{
+  char const *base = name + FILE_SYSTEM_PREFIX_LEN (name);
+  char const *p;
+  bool saw_slash = false;
+
+  while (ISSLASH (*base))
+    base++;
+
+  for (p = base; *p; p++)
+    {
+      if (ISSLASH (*p))
+        saw_slash = true;
+      else if (saw_slash)
+        {
+          base = p;
+          saw_slash = false;
+        }
+    }
+
+  return (char *) base;
+}
+
+/* Return the length of the basename NAME.  Typically NAME is the
+   value returned by base_name or last_component.  Act like strlen
+   (NAME), except omit all trailing slashes.  */
+
+size_t
+base_len (char const *name)
+{
+  size_t len;
+  size_t prefix_len = FILE_SYSTEM_PREFIX_LEN (name);
+
+  for (len = strlen (name);  1 < len && ISSLASH (name[len - 1]);  len--)
+    continue;
+
+  if (DOUBLE_SLASH_IS_DISTINCT_ROOT && len == 1
+      && ISSLASH (name[0]) && ISSLASH (name[1]) && ! name[2])
+    return 2;
+
+  if (FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE && prefix_len
+      && len == prefix_len && ISSLASH (name[prefix_len]))
+    return prefix_len + 1;
+
+  return len;
+}