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, 210 insertions, 0 deletions

diff --git a/gdbserver/server.h b/gdbserver/server.h
new file mode 100644
index 00000000000..3c286862349
--- /dev/null
+++ b/gdbserver/server.h
@@ -0,0 +1,210 @@
+/* Common definitions for remote server for GDB.
+   Copyright (C) 1993-2020 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_SERVER_H
+#define GDBSERVER_SERVER_H
+
+#include "gdbsupport/common-defs.h"
+
+#undef PACKAGE
+#undef PACKAGE_NAME
+#undef PACKAGE_VERSION
+#undef PACKAGE_STRING
+#undef PACKAGE_TARNAME
+
+#include <config.h>
+
+gdb_static_assert (sizeof (CORE_ADDR) >= sizeof (void *));
+
+#ifdef __MINGW32CE__
+#include "wincecompat.h"
+#endif
+
+#include "gdbsupport/version.h"
+
+#if !HAVE_DECL_PERROR
+#ifndef perror
+extern void perror (const char *);
+#endif
+#endif
+
+#if !HAVE_DECL_VASPRINTF
+extern int vasprintf(char **strp, const char *fmt, va_list ap);
+#endif
+#if !HAVE_DECL_VSNPRINTF
+int vsnprintf(char *str, size_t size, const char *format, va_list ap);
+#endif
+
+#ifdef IN_PROCESS_AGENT
+#  define PROG "ipa"
+#else
+#  define PROG "gdbserver"
+#endif
+
+#include "gdbsupport/buffer.h"
+#include "gdbsupport/xml-utils.h"
+#include "regcache.h"
+#include "gdbsupport/gdb_signals.h"
+#include "target.h"
+#include "mem-break.h"
+#include "gdbsupport/environ.h"
+
+/* Target-specific functions */
+
+void initialize_low ();
+
+/* Public variables in server.c */
+
+extern bool server_waiting;
+
+extern bool disable_packet_vCont;
+extern bool disable_packet_Tthread;
+extern bool disable_packet_qC;
+extern bool disable_packet_qfThreadInfo;
+
+extern bool run_once;
+extern bool non_stop;
+
+#if USE_WIN32API
+#include <winsock2.h>
+typedef SOCKET gdb_fildes_t;
+#else
+typedef int gdb_fildes_t;
+#endif
+
+#include "event-loop.h"
+
+/* Functions from server.c.  */
+extern void handle_v_requests (char *own_buf, int packet_len,
+			       int *new_packet_len);
+extern int handle_serial_event (int err, gdb_client_data client_data);
+extern int handle_target_event (int err, gdb_client_data client_data);
+
+/* Get rid of the currently pending stop replies that match PTID.  */
+extern void discard_queued_stop_replies (ptid_t ptid);
+
+/* Returns true if there's a pending stop reply that matches PTID in
+   the vStopped notifications queue.  */
+extern int in_queued_stop_replies (ptid_t ptid);
+
+#include "remote-utils.h"
+
+#include "utils.h"
+#include "debug.h"
+#include "gdbsupport/gdb_vecs.h"
+
+/* Maximum number of bytes to read/write at once.  The value here
+   is chosen to fill up a packet (the headers account for the 32).  */
+#define MAXBUFBYTES(N) (((N)-32)/2)
+
+/* Buffer sizes for transferring memory, registers, etc.   Set to a constant
+   value to accomodate multiple register formats.  This value must be at least
+   as large as the largest register set supported by gdbserver.  */
+#define PBUFSIZ 18432
+
+/* Definition for an unknown syscall, used basically in error-cases.  */
+#define UNKNOWN_SYSCALL (-1)
+
+/* Definition for any syscall, used for unfiltered syscall reporting.  */
+#define ANY_SYSCALL (-2)
+
+/* After fork_inferior has been called, we need to adjust a few
+   signals and call startup_inferior to start the inferior and consume
+   its first events.  This is done here.  PID is the pid of the new
+   inferior and PROGRAM is its name.  */
+extern void post_fork_inferior (int pid, const char *program);
+
+/* Get the gdb_environ being used in the current session.  */
+extern gdb_environ *get_environ ();
+
+extern unsigned long signal_pid;
+
+
+/* Description of the client remote protocol state for the currently
+   connected client.  */
+
+struct client_state
+{
+  client_state ():
+    own_buf ((char *) xmalloc (PBUFSIZ + 1)) 
+  {}
+
+  /* The thread set with an `Hc' packet.  `Hc' is deprecated in favor of
+     `vCont'.  Note the multi-process extensions made `vCont' a
+     requirement, so `Hc pPID.TID' is pretty much undefined.  So
+     CONT_THREAD can be null_ptid for no `Hc' thread, minus_one_ptid for
+     resuming all threads of the process (again, `Hc' isn't used for
+     multi-process), or a specific thread ptid_t.  */
+  ptid_t cont_thread;
+
+  /* The thread set with an `Hg' packet.  */
+  ptid_t general_thread;
+
+  int multi_process = 0;
+  int report_fork_events = 0;
+  int report_vfork_events = 0;
+  int report_exec_events = 0;
+  int report_thread_events = 0;
+
+  /* True if the "swbreak+" feature is active.  In that case, GDB wants
+     us to report whether a trap is explained by a software breakpoint
+     and for the server to handle PC adjustment if necessary on this
+     target.  Only enabled if the target supports it.  */
+  int swbreak_feature = 0;
+  /* True if the "hwbreak+" feature is active.  In that case, GDB wants
+     us to report whether a trap is explained by a hardware breakpoint.
+     Only enabled if the target supports it.  */
+  int hwbreak_feature = 0;
+
+  /* True if the "vContSupported" feature is active.  In that case, GDB
+     wants us to report whether single step is supported in the reply to
+     "vCont?" packet.  */
+  int vCont_supported = 0;
+
+  /* Whether we should attempt to disable the operating system's address
+     space randomization feature before starting an inferior.  */
+  int disable_randomization = 1;
+
+  int pass_signals[GDB_SIGNAL_LAST];
+  int program_signals[GDB_SIGNAL_LAST];
+  int program_signals_p = 0;
+
+  /* Last status reported to GDB.  */
+  struct target_waitstatus last_status;
+  ptid_t last_ptid;
+
+  char *own_buf;
+
+  /* If true, then GDB has requested noack mode.  */
+  int noack_mode = 0;
+  /* If true, then we tell GDB to use noack mode by default.  */
+  int transport_is_reliable = 0;
+
+  /* The traceframe to be used as the source of data to send back to
+     GDB.  A value of -1 means to get data from the live program.  */
+
+  int current_traceframe = -1;
+
+};
+
+client_state &get_client_state ();
+
+#include "gdbthread.h"
+#include "inferiors.h"
+
+#endif /* GDBSERVER_SERVER_H */