Move gnulib to top level

This patch moves the gdb/gnulib subdirectory to the top level.

It adjusts the top-level build system to build gnulib when necessary,
and changes gdb to use this.  However, gdbserver still builds its own
copy of gnulib, just from the new source location.

A small hack was needed to ensure that gnulib is only built when gdb
is enabled.  The Makefile only provides an ordering -- the directory
must be mentioned in configdirs to actually be compiled at all.

Most of the patch is just a "git mv" of gnulib, though a few minor
path adjustments were needed in some files there.

Tested by the buildbot.

ChangeLog
2019-06-14  Tom Tromey  <tom@tromey.com>

	* MAINTAINERS: Add gnulib.
	* gnulib: New directory, move from gdb/gnulib.
	* configure.ac (host_libs): Add gnulib.
	* configure: Rebuild.
	* Makefile.def (host_modules, dependencies): Add gnulib.
	* Makefile.in: Rebuild.

gdb/ChangeLog
2019-06-14  Tom Tromey  <tom@tromey.com>

	* gnulib: Move directory to top-level.
	* configure.ac: Don't configure gnulib.
	* configure: Rebuild.
	* common/common-defs.h: Use new path to gnulib.
	* Makefile.in (GNULIB_BUILDDIR): Now ../gnulib.
	(GNULIB_H): Remove.
	(INCGNU): Look in new gnulib location.
	(HFILES_NO_SRCDIR): Remove gnulib files.
	(SUBDIR, REQUIRED_SUBDIRS): Remove gnulib.
	(generated_files): Remove GNULIB_H.
	($(LIBGNU), all-lib): Remove targets.
	(distclean): Don't mention GNULIB_BUILDDIR.
	($(GNULIB_BUILDDIR)/Makefile): Remove target.

gdb/gdbserver/ChangeLog
2019-06-14  Tom Tromey  <tom@tromey.com>

	* configure.ac: Use new path to gnulib.
	* configure: Rebuild.
	* Makefile.in (INCGNU, $(GNULIB_BUILDDIR)/Makefile): Use new path
	to gnulib.

gnulib/ChangeLog
2019-06-14  Tom Tromey  <tom@tromey.com>

	* update-gnulib.sh: Adjust paths.
	* Makefile.in: Adjust paths.
	* configure.ac: Adjust paths.  Use ACX_LARGEFILE.
	* configure: Rebuild.

1 files changed, 98 insertions, 0 deletions

diff --git a/gnulib/import/readdir.c b/gnulib/import/readdir.c
new file mode 100644
index 00000000000..76b7e9d819b
--- /dev/null
+++ b/gnulib/import/readdir.c
@@ -0,0 +1,98 @@
+/* Read the next entry of a directory.
+   Copyright (C) 2011-2016 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>
+
+/* Specification.  */
+#include <dirent.h>
+
+#include <errno.h>
+#include <stddef.h>
+
+#include "dirent-private.h"
+
+struct dirent *
+readdir (DIR *dirp)
+{
+  char type;
+  struct dirent *result;
+
+  /* There is no need to add code to produce entries for "." and "..".
+     According to the POSIX:2008 section "4.12 Pathname Resolution"
+     <http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html>
+     "." and ".." are syntactic entities.
+     POSIX also says:
+       "If entries for dot or dot-dot exist, one entry shall be returned
+        for dot and one entry shall be returned for dot-dot; otherwise,
+        they shall not be returned."  */
+
+  switch (dirp->status)
+    {
+    case -2:
+      /* End of directory already reached.  */
+      return NULL;
+    case -1:
+      break;
+    case 0:
+      if (!FindNextFile (dirp->current, &dirp->entry))
+        {
+          switch (GetLastError ())
+            {
+            case ERROR_NO_MORE_FILES:
+              dirp->status = -2;
+              return NULL;
+            default:
+              errno = EIO;
+              return NULL;
+            }
+        }
+      break;
+    default:
+      errno = dirp->status;
+      return NULL;
+    }
+
+  dirp->status = 0;
+
+  if (dirp->entry.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
+    type = DT_DIR;
+  else if (dirp->entry.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)
+    type = DT_LNK;
+  else if ((dirp->entry.dwFileAttributes
+            & ~(FILE_ATTRIBUTE_READONLY
+                | FILE_ATTRIBUTE_HIDDEN
+                | FILE_ATTRIBUTE_SYSTEM
+                | FILE_ATTRIBUTE_ARCHIVE
+                | FILE_ATTRIBUTE_NORMAL
+                | FILE_ATTRIBUTE_TEMPORARY
+                | FILE_ATTRIBUTE_SPARSE_FILE
+                | FILE_ATTRIBUTE_COMPRESSED
+                | FILE_ATTRIBUTE_NOT_CONTENT_INDEXED
+                | FILE_ATTRIBUTE_ENCRYPTED)) == 0)
+    /* Devices like COM1, LPT1, NUL would also have the attributes 0x20 but
+       they cannot occur here.  */
+    type = DT_REG;
+  else
+    type = DT_UNKNOWN;
+
+  /* Reuse the memory of dirp->entry for the result.  */
+  result =
+    (struct dirent *)
+    ((char *) dirp->entry.cFileName - offsetof (struct dirent, d_name[0]));
+  result->d_type = type;
+
+  return result;
+}