First steps toward native path handling.

- /proc and /dev are are still available, accessed as
  proc:/ and dev:/
- All other paths are native, and do not "see" virtual Cygwin
  items; /cygdrive is just C:\cygdrive (if the current drive
  is C).
- chdir() to a virtual directory like dev:/ or proc:/ results
  in errno EOPNOTSUPP.

* winsup/cygwin/mount.cc (mount_info::conv_to_win32_path):
Takes new bool argument, hide_cygwin_virtuals. If true all
that the function does is "backslashify" the path.
(mount_info::add_item): Special hack inserted here so that
we can create the virtual root directory which holds dev
and proc and whatnot, and is passed here as "/". We cannot let
this go through normalize_posix_path any more because it
will turn to C:\.

* winsup/cygwin/mount.h (mount_info::conv_to_win32_path):
Declaration updated.

* winsup/cygwin/path.cc (is_posix_space): New static function:
tests for paths in special spaces, currently "dev:/" and
"proc:/". Used by normalize_posix_path.
(normalize_posix_path): Any path that doesn't satisfy the
is_posix_space test is treated as Win32.
Since the bulk of the code is now only used for these
spaces, the relative path handling is not required
and a the corresponding block of code is removed.
Paths satisfying is_posix_space are transformed.
I.e. the underlying path resolution machine in the path_conv
class still recognizes /proc and /dev. It's just that these
will not occur, because normalize_posix_path will convert
them to references with drive names.
(path_conv::check): Pass the is_msdos flag down to
mount_info::conv_to_win32_path as the new argument. Thus
if normalize_posix_path indicates a native path, this function
will hide the virtual spaces. Also, we add PATH_NOPOSIX and
PATH_NOACL to the object's path_flags. This is used in
chdir.
(normalize_win32_path): A small piece of logic works against
our plan here: it checks for the leading forward slash on the
path, and prevents such paths from being converted to Win32
paths with a drive reference. We eliminate this test, and
treat paths unconditionally.
(chdir): Here, if the path is not native, we return
EOPNOTSUPP. Thus it is impossible to chdir into Cygwin
virtual directories like /dev (now referenced as dev:/).
They can be listed but not turned into the current directory.
Eventually we want chdir to actually set the Win32 current
directory of the process; that can't work for virtual
dirs.

* winsup/cygwin/path.h (path_conv::is_native): New inline
accessor which tests for the PATH_NOPOSIX flag.

1 files changed, 1 insertions, 0 deletions

diff --git a/winsup/cygwin/path.h b/winsup/cygwin/path.h
index 1e2af6550..c6f43c183 100644
--- a/winsup/cygwin/path.h
+++ b/winsup/cygwin/path.h
@@ -161,6 +161,7 @@ class path_conv
   bool has_acls () const {return !(path_flags & PATH_NOACL) && fs.has_acls (); }
   bool hasgood_inode () const {return !(path_flags & PATH_IHASH); }
   bool isgood_inode (ino_t ino) const;
+  bool is_native () const {return !!(path_flags & PATH_NOPOSIX);}
   bool support_sparse () const
   {
     return (path_flags & PATH_SPARSE)