* Makefile.in: Build wincap.o.

* wincap.cc: New file.
        * wincap.h: Ditto.
        * autoload.cc: Add dynamic load statement for `CreateHardLinkA'.
        * dcrt0.cc (os_being_run): Eliminated.
        (osname): Ditto.
        (iswinnt): Ditto.
        (set_os_type): Ditto.
        (dll_crt0_1): Call wincap.init() instead of set_os_type().
        (_dll_crt0): Ditto.
        * environ.cc (set_chunksize): New function.
        (parse_thing): `forkchunk' setting now invokes function `set_chunksize'.
        * fork.cc (chunksize): Eliminated. Moved to be member of wincap.
        * host_dependent.h: Removed.
        * syscalls.cc (_link): Try using `CreateHardLinkA' first, if available.
        * cygheap.cc, dcrt0.cc, delqueue.cc, dir.cc,
        environ.cc, fhandler.cc, fhandler.h, fhandler_console.cc,
        fhandler_mem.cc, fork.cc, mmap.cc, net.cc, pinfo.cc, pinfo.h,
        security.cc, syscalls.cc, sysconf.cc, syslog.cc, thread.cc,
        times.cc, tty.cc, uinfo.cc, uname.cc, winsup.h: Use new wincap
        capability check throughout.
        * winsup.h: Include wincap.h. Eliminate extern declarations of
        `os_being_run' and `iswinnt'. Eliminate `os_type" definition.
        * include/cygwin/version.h: Bump version to 1.3.4.

winsup/cygwin/syscalls.cc

@@ -150,7 +150,7 @@ _unlink (const char *ourname)
   /* Windows 9x seems to report ERROR_ACCESS_DENIED rather than sharing
      violation.  So, set lasterr to ERROR_SHARING_VIOLATION in this case
      to simplify tests. */
-  if (!iswinnt && lasterr == ERROR_ACCESS_DENIED
+  if (wincap.access_denied_on_delete () && lasterr == ERROR_ACCESS_DENIED
       && !win32_name.isremote ())
     lasterr = ERROR_SHARING_VIOLATION;
 
@@ -168,7 +168,8 @@ _unlink (const char *ourname)
 
   bool delete_on_close_ok;
 
-  delete_on_close_ok  = !win32_name.isremote () && iswinnt;
+  delete_on_close_ok  = !win32_name.isremote ()
+  			&& wincap.has_delete_on_close ();
 
   /* Attempt to use "delete on close" semantics to handle removing
      a file which may be open. */
@@ -609,8 +610,14 @@ _link (const char *a, const char *b)
     }
 
   /* Try to make hard link first on Windows NT */
-  if (iswinnt)
+  if (wincap.has_hard_links ())
     {
+      if (CreateHardLinkA (real_b.get_win32 (), real_a.get_win32 (), NULL))
+	{
+	  res = 0;
+	  goto done;
+	}
+
       HANDLE hFileSource;
 
       WIN32_STREAM_ID StreamId;
@@ -726,7 +733,7 @@ chown_worker (const char *name, unsigned fmode, uid_t uid, gid_t gid)
   if (check_null_empty_str_errno (name))
     return -1;
 
-  if (!iswinnt)    // real chown only works on NT
+  if (!wincap.has_security ())  // real chown only works on NT
     res = 0;			// return zero (and do nothing) under Windows 9x
   else
     {
@@ -1093,7 +1100,7 @@ stat_worker (const char *caller, const char *name, struct stat *buf,
   dtype = real_path.get_drive_type ();
 
   if ((atts == -1 || ! (atts & FILE_ATTRIBUTE_DIRECTORY) ||
-       (iswinnt
+       (wincap.can_open_directories ()
 	&& dtype != DRIVE_NO_ROOT_DIR
 	&& dtype != DRIVE_UNKNOWN)))
     {
@@ -1357,7 +1364,7 @@ _rename (const char *oldpath, const char *newpath)
 		   && GetLastError () != ERROR_FILE_EXISTS))
     goto done;
 
-  if (iswinnt)
+  if (wincap.has_move_file_ex ())
     {
       if (MoveFileEx (real_old.get_win32 (), real_new.get_win32 (),
 		      MOVEFILE_REPLACE_EXISTING))
@@ -1481,7 +1488,7 @@ check_posix_perm (const char *fname, int v)
   extern int allow_ntea, allow_ntsec, allow_smbntsec;
 
   /* Windows 95/98/ME don't support file system security at all. */
-  if (!iswinnt)
+  if (!wincap.has_security ())
     return 0;
 
   /* ntea is ok for supporting permission bits but it doesn't support
@@ -2022,7 +2029,7 @@ extern "C" int
 seteuid (uid_t uid)
 {
   sigframe thisframe (mainthread);
-  if (iswinnt)
+  if (wincap.has_security ())
     {
       char orig_username[UNLEN + 1];
       char orig_domain[INTERNET_MAX_HOST_NAME_LENGTH + 1];
@@ -2237,7 +2244,7 @@ extern "C" int
 setegid (gid_t gid)
 {
   sigframe thisframe (mainthread);
-  if (iswinnt)
+  if (wincap.has_security ())
     {
       if (gid != (gid_t) -1)
 	{