Move gdbsupport to the top level

This patch moves the gdbsupport directory to the top level.  This is
the next step in the ongoing project to move gdbserver to the top
level.

The bulk of this patch was created by "git mv gdb/gdbsupport gdbsupport".

This patch then adds a build system to gdbsupport and wires it into
the top level.  Then it changes gdb to use the top-level build.

gdbserver, on the other hand, is not yet changed.  It still does its
own build of gdbsupport.

ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* src-release.sh (GDB_SUPPORT_DIRS): Add gdbsupport.
	* MAINTAINERS: Add gdbsupport.
	* configure: Rebuild.
	* configure.ac (configdirs): Add gdbsupport.
	* gdbsupport: New directory, move from gdb/gdbsupport.
	* Makefile.def (host_modules, dependencies): Add gnulib.
	* Makefile.in: Rebuild.

gdb/ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* nat/x86-linux-dregs.c: Include configh.h.
	* nat/linux-ptrace.c: Include configh.h.
	* nat/linux-btrace.c: Include configh.h.
	* defs.h: Include config.h, bfd.h.
	* configure.ac: Don't source common.host.
	(CONFIG_OBS, CONFIG_SRCS): Remove gdbsupport files.
	* configure: Rebuild.
	* acinclude.m4: Update path.
	* Makefile.in (SUPPORT, LIBSUPPORT, INCSUPPORT): New variables.
	(CONFIG_SRC_SUBDIR): Remove gdbsupport.
	(INTERNAL_CFLAGS_BASE): Add INCSUPPORT.
	(CLIBS): Add LIBSUPPORT.
	(CDEPS): Likewise.
	(COMMON_SFILES): Remove gdbsupport files.
	(HFILES_NO_SRCDIR): Likewise.
	(stamp-version): Update path to create-version.sh.
	(ALLDEPFILES): Remove gdbsupport files.

gdb/gdbserver/ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* server.h: Include config.h.
	* gdbreplay.c: Include config.h.
	* configure: Rebuild.
	* configure.ac: Don't source common.host.
	* acinclude.m4: Update path.
	* Makefile.in (INCSUPPORT): New variable.
	(INCLUDE_CFLAGS): Add INCSUPPORT.
	(SFILES): Update paths.
	(version-generated.c): Update path to create-version.sh.
	(gdbsupport/%-ipa.o, gdbsupport/%.o): Update paths.

gdbsupport/ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* common-defs.h: Add GDBSERVER case.  Update includes.
	* acinclude.m4, aclocal.m4, config.in, configure, configure.ac,
	Makefile.am, Makefile.in, README: New files.
	* Moved from ../gdb/gdbsupport/

Change-Id: I07632e7798635c1bab389bf885971e584fb4bb78

1 files changed, 70 insertions, 0 deletions

diff --git a/gdbsupport/alt-stack.h b/gdbsupport/alt-stack.h
new file mode 100644
index 0000000..e7c6b2f
--- /dev/null
+++ b/gdbsupport/alt-stack.h
@@ -0,0 +1,70 @@
+/* Temporarily install an alternate signal stack
+
+   Copyright (C) 2019-2020 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 GDBSUPPORT_ALT_STACK_H
+#define GDBSUPPORT_ALT_STACK_H
+
+#include <signal.h>
+
+namespace gdb
+{
+
+/* Try to set up an alternate signal stack for SIGSEGV handlers.
+   This allows us to handle SIGSEGV signals generated when the
+   normal process stack is exhausted.  If this stack is not set
+   up (sigaltstack is unavailable or fails) and a SIGSEGV is
+   generated when the normal stack is exhausted then the program
+   will behave as though no SIGSEGV handler was installed.  */
+class alternate_signal_stack
+{
+public:
+  alternate_signal_stack ()
+  {
+#ifdef HAVE_SIGALTSTACK
+    m_stack.reset ((char *) xmalloc (SIGSTKSZ));
+
+    stack_t stack;
+    stack.ss_sp = m_stack.get ();
+    stack.ss_size = SIGSTKSZ;
+    stack.ss_flags = 0;
+
+    sigaltstack (&stack, &m_old_stack);
+#endif
+  }
+
+  ~alternate_signal_stack ()
+  {
+#ifdef HAVE_SIGALTSTACK
+    sigaltstack (&m_old_stack, nullptr);
+#endif
+  }
+
+  DISABLE_COPY_AND_ASSIGN (alternate_signal_stack);
+
+private:
+
+#ifdef HAVE_SIGALTSTACK
+  gdb::unique_xmalloc_ptr<char> m_stack;
+  stack_t m_old_stack;
+#endif
+};
+
+}
+
+#endif /* GDBSUPPORT_ALT_STACK_H */