Move gdbserver to top level

This patch moves gdbserver to the top level.

This patch is as close to a pure move as possible -- gdbserver still
builds its own variant of gnulib and gdbsupport.  Changing this will
be done in a separate patch.

[v2] Note that, per Simon's review comment, this patch changes the
tree so that gdbserver is not built for or1k or score.  This makes
sense, because there is apparently not actually a gdbserver port here.

[v3] This version of the patch also splits out some configury into a
new file, gdbserver/configure.host, so that the top-level configure
script can simply rely on it in order to decide whether gdbserver
should be built.

[v4] This version adds documentation and removes some unnecessary
top-level dependencies.

[v5] Update docs to mention "make all-gdbserver" and change how
top-level configure decides whether to build gdbserver, switching to a
single, shared script.

Tested by the buildbot.

ChangeLog
2020-02-07  Tom Tromey  <tom@tromey.com>
	    Pedro Alves  <palves@redhat.com>

	* src-release.sh (GDB_SUPPORT_DIRS): Add gdbserver.
	* gdbserver: New directory, moved from gdb/gdbserver.
	* configure.ac (host_tools): Add gdbserver.
	Only build gdbserver on certain systems.
	* Makefile.in, configure: Rebuild.
	* Makefile.def (host_modules, dependencies): Add gdbserver.
	* MAINTAINERS: Add gdbserver.

gdb/ChangeLog
2020-02-07  Tom Tromey  <tom@tromey.com>

	* README: Update gdbserver documentation.
	* gdbserver: Move to top level.
	* configure.tgt (build_gdbserver): Remove.
	* configure.ac: Remove --enable-gdbserver.
	* configure: Rebuild.
	* Makefile.in (distclean): Don't mention gdbserver.

Change-Id: I826b7565b54604711dc7a11edea0499cd51ff39e

1 files changed, 65 insertions, 0 deletions

diff --git a/gdbserver/debug.h b/gdbserver/debug.h
new file mode 100644
index 0000000..b026ee7
--- /dev/null
+++ b/gdbserver/debug.h
@@ -0,0 +1,65 @@
+/* Debugging routines for the remote server for GDB.
+   Copyright (C) 2014-2020 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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/>.  */
+
+#ifndef GDBSERVER_DEBUG_H
+#define GDBSERVER_DEBUG_H
+
+#if !defined (IN_PROCESS_AGENT)
+extern int remote_debug;
+
+/* Switch all debug output to DEBUG_FILE.  If DEBUG_FILE is nullptr or an
+   empty string, or if the file cannot be opened, then debug output is sent to
+   stderr.  */
+void debug_set_output (const char *debug_file);
+#endif
+
+extern int using_threads;
+
+/* Enable miscellaneous debugging output.  The name is historical - it
+   was originally used to debug LinuxThreads support.  */
+
+extern int debug_threads;
+
+extern int debug_timestamp;
+
+void debug_flush (void);
+void do_debug_enter (const char *function_name);
+void do_debug_exit (const char *function_name);
+
+/* Async signal safe debug output function that calls write directly.  */
+ssize_t debug_write (const void *buf, size_t nbyte);
+
+/* These macros are for use in major functions that produce a lot of
+   debugging output.  They help identify in the mass of debugging output
+   when these functions enter and exit.  debug_enter is intended to be
+   called at the start of a function, before any other debugging output.
+   debug_exit is intended to be called at the end of the same function,
+   after all debugging output.  */
+#ifdef FUNCTION_NAME
+#define debug_enter() \
+  do { do_debug_enter (FUNCTION_NAME); } while (0)
+#define debug_exit() \
+  do { do_debug_exit (FUNCTION_NAME); } while (0)
+#else
+#define debug_enter() \
+  do { } while (0)
+#define debug_exit() \
+  do { } while (0)
+#endif
+
+#endif /* GDBSERVER_DEBUG_H */