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, 141 insertions, 0 deletions

diff --git a/gdbserver/regcache.h b/gdbserver/regcache.h
new file mode 100644
index 0000000..8725707
--- /dev/null
+++ b/gdbserver/regcache.h
@@ -0,0 +1,141 @@
+/* Register support routines for the remote server for GDB.
+   Copyright (C) 2001-2020 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_REGCACHE_H
+#define GDBSERVER_REGCACHE_H
+
+#include "gdbsupport/common-regcache.h"
+
+struct thread_info;
+struct target_desc;
+
+/* The data for the register cache.  Note that we have one per
+   inferior; this is primarily for simplicity, as the performance
+   benefit is minimal.  */
+
+struct regcache : public reg_buffer_common
+{
+  /* The regcache's target description.  */
+  const struct target_desc *tdesc = nullptr;
+
+  /* Whether the REGISTERS buffer's contents are valid.  If false, we
+     haven't fetched the registers from the target yet.  Not that this
+     register cache is _not_ pass-through, unlike GDB's.  Note that
+     "valid" here is unrelated to whether the registers are available
+     in a traceframe.  For that, check REGISTER_STATUS below.  */
+  int registers_valid = 0;
+  int registers_owned = 0;
+  unsigned char *registers = nullptr;
+#ifndef IN_PROCESS_AGENT
+  /* One of REG_UNAVAILABLE or REG_VALID.  */
+  unsigned char *register_status = nullptr;
+#endif
+
+  /* See gdbsupport/common-regcache.h.  */
+  enum register_status get_register_status (int regnum) const override;
+
+  /* See gdbsupport/common-regcache.h.  */
+  void raw_supply (int regnum, const void *buf) override;
+
+  /* See gdbsupport/common-regcache.h.  */
+  void raw_collect (int regnum, void *buf) const override;
+
+  /* See gdbsupport/common-regcache.h.  */
+  bool raw_compare (int regnum, const void *buf, int offset) const override;
+};
+
+struct regcache *init_register_cache (struct regcache *regcache,
+				      const struct target_desc *tdesc,
+				      unsigned char *regbuf);
+
+void regcache_cpy (struct regcache *dst, struct regcache *src);
+
+/* Create a new register cache for INFERIOR.  */
+
+struct regcache *new_register_cache (const struct target_desc *tdesc);
+
+struct regcache *get_thread_regcache (struct thread_info *thread, int fetch);
+
+/* Release all memory associated with the register cache for INFERIOR.  */
+
+void free_register_cache (struct regcache *regcache);
+
+/* Invalidate cached registers for one thread.  */
+
+void regcache_invalidate_thread (struct thread_info *);
+
+/* Invalidate cached registers for all threads of the given process.  */
+
+void regcache_invalidate_pid (int pid);
+
+/* Invalidate cached registers for all threads of the current
+   process.  */
+
+void regcache_invalidate (void);
+
+/* Invalidate and release the register cache of all threads of the
+   current process.  */
+
+void regcache_release (void);
+
+/* Convert all registers to a string in the currently specified remote
+   format.  */
+
+void registers_to_string (struct regcache *regcache, char *buf);
+
+/* Convert a string to register values and fill our register cache.  */
+
+void registers_from_string (struct regcache *regcache, char *buf);
+
+/* For regcache_read_pc see gdbsupport/common-regcache.h.  */
+
+void regcache_write_pc (struct regcache *regcache, CORE_ADDR pc);
+
+int register_cache_size (const struct target_desc *tdesc);
+
+int register_size (const struct target_desc *tdesc, int n);
+
+int find_regno (const struct target_desc *tdesc, const char *name);
+
+void supply_register (struct regcache *regcache, int n, const void *buf);
+
+void supply_register_zeroed (struct regcache *regcache, int n);
+
+void supply_register_by_name (struct regcache *regcache,
+			      const char *name, const void *buf);
+
+void supply_register_by_name_zeroed (struct regcache *regcache,
+				     const char *name);
+
+void supply_regblock (struct regcache *regcache, const void *buf);
+
+void collect_register (struct regcache *regcache, int n, void *buf);
+
+void collect_register_as_string (struct regcache *regcache, int n, char *buf);
+
+void collect_register_by_name (struct regcache *regcache,
+			       const char *name, void *buf);
+
+/* Read a raw register as an unsigned integer.  Convenience wrapper
+   around regcache_raw_get_unsigned that takes a register name instead
+   of a register number.  */
+
+ULONGEST regcache_raw_get_unsigned_by_name (struct regcache *regcache,
+					    const char *name);
+
+#endif /* GDBSERVER_REGCACHE_H */