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, 80 insertions, 0 deletions

diff --git a/gdbserver/dll.c b/gdbserver/dll.c
new file mode 100644
index 00000000000..fdc7becfbee
--- /dev/null
+++ b/gdbserver/dll.c
@@ -0,0 +1,80 @@
+/* Copyright (C) 2002-2020 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/>.  */
+
+#include "server.h"
+#include "dll.h"
+
+#include <algorithm>
+
+/* An "unspecified" CORE_ADDR, for match_dll.  */
+#define UNSPECIFIED_CORE_ADDR (~(CORE_ADDR) 0)
+
+std::list<dll_info> all_dlls;
+int dlls_changed;
+
+/* Record a newly loaded DLL at BASE_ADDR.  */
+
+void
+loaded_dll (const char *name, CORE_ADDR base_addr)
+{
+  all_dlls.emplace_back (name != NULL ? name : "", base_addr);
+  dlls_changed = 1;
+}
+
+/* Record that the DLL with NAME and BASE_ADDR has been unloaded.  */
+
+void
+unloaded_dll (const char *name, CORE_ADDR base_addr)
+{
+  auto pred = [&] (const dll_info &dll)
+    {
+      if (base_addr != UNSPECIFIED_CORE_ADDR
+	  && base_addr == dll.base_addr)
+	return true;
+
+      if (name != NULL && dll.name == name)
+	return true;
+
+      return false;
+    };
+
+  auto iter = std::find_if (all_dlls.begin (), all_dlls.end (), pred);
+
+  if (iter == all_dlls.end ())
+    /* For some inferiors we might get unloaded_dll events without having
+       a corresponding loaded_dll.  In that case, the dll cannot be found
+       in ALL_DLL, and there is nothing further for us to do.
+
+       This has been observed when running 32bit executables on Windows64
+       (i.e. through WOW64, the interface between the 32bits and 64bits
+       worlds).  In that case, the inferior always does some strange
+       unloading of unnamed dll.  */
+    return;
+  else
+    {
+      /* DLL has been found so remove the entry and free associated
+         resources.  */
+      all_dlls.erase (iter);
+      dlls_changed = 1;
+    }
+}
+
+void
+clear_dlls (void)
+{
+  all_dlls.clear ();
+}