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, 280 insertions, 0 deletions

diff --git a/gdbsupport/agent.c b/gdbsupport/agent.c
new file mode 100644
index 0000000..b4127ff
--- /dev/null
+++ b/gdbsupport/agent.c
@@ -0,0 +1,280 @@
+/* Shared utility routines for GDB to interact with agent.
+
+   Copyright (C) 2009-2020 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 "common-defs.h"
+#include "target/target.h"
+#include "gdbsupport/symbol.h"
+#include <unistd.h>
+#include "filestuff.h"
+
+#define IPA_SYM_STRUCT_NAME ipa_sym_addresses_common
+#include "agent.h"
+
+bool debug_agent = false;
+
+/* A stdarg wrapper for debug_vprintf.  */
+
+static void ATTRIBUTE_PRINTF (1, 2)
+debug_agent_printf (const char *fmt, ...)
+{
+  va_list ap;
+
+  if (!debug_agent)
+    return;
+  va_start (ap, fmt);
+  debug_vprintf (fmt, ap);
+  va_end (ap);
+}
+
+#define DEBUG_AGENT debug_agent_printf
+
+/* Global flag to determine using agent or not.  */
+bool use_agent = false;
+
+/* Addresses of in-process agent's symbols both GDB and GDBserver cares
+   about.  */
+
+struct ipa_sym_addresses_common
+{
+  CORE_ADDR addr_helper_thread_id;
+  CORE_ADDR addr_cmd_buf;
+  CORE_ADDR addr_capability;
+};
+
+/* Cache of the helper thread id.  FIXME: this global should be made
+   per-process.  */
+static uint32_t helper_thread_id = 0;
+
+static struct
+{
+  const char *name;
+  int offset;
+} symbol_list[] = {
+  IPA_SYM(helper_thread_id),
+  IPA_SYM(cmd_buf),
+  IPA_SYM(capability),
+};
+
+static struct ipa_sym_addresses_common ipa_sym_addrs;
+
+static bool all_agent_symbols_looked_up = false;
+
+bool
+agent_loaded_p (void)
+{
+  return all_agent_symbols_looked_up;
+}
+
+/* Look up all symbols needed by agent.  Return 0 if all the symbols are
+   found, return non-zero otherwise.  */
+
+int
+agent_look_up_symbols (void *arg)
+{
+  all_agent_symbols_looked_up = false;
+
+  for (int i = 0; i < sizeof (symbol_list) / sizeof (symbol_list[0]); i++)
+    {
+      CORE_ADDR *addrp =
+	(CORE_ADDR *) ((char *) &ipa_sym_addrs + symbol_list[i].offset);
+      struct objfile *objfile = (struct objfile *) arg;
+
+      if (find_minimal_symbol_address (symbol_list[i].name, addrp,
+				       objfile) != 0)
+	{
+	  DEBUG_AGENT ("symbol `%s' not found\n", symbol_list[i].name);
+	  return -1;
+	}
+    }
+
+  all_agent_symbols_looked_up = true;
+  return 0;
+}
+
+static unsigned int
+agent_get_helper_thread_id (void)
+{
+  if  (helper_thread_id == 0)
+    {
+      if (target_read_uint32 (ipa_sym_addrs.addr_helper_thread_id,
+			      &helper_thread_id))
+	warning (_("Error reading helper thread's id in lib"));
+    }
+
+  return helper_thread_id;
+}
+
+#ifdef HAVE_SYS_UN_H
+#include <sys/socket.h>
+#include <sys/un.h>
+#define SOCK_DIR P_tmpdir
+
+#ifndef UNIX_PATH_MAX
+#define UNIX_PATH_MAX sizeof(((struct sockaddr_un *) NULL)->sun_path)
+#endif
+
+#endif
+
+/* Connects to synchronization socket.  PID is the pid of inferior, which is
+   used to set up the connection socket.  */
+
+static int
+gdb_connect_sync_socket (int pid)
+{
+#ifdef HAVE_SYS_UN_H
+  struct sockaddr_un addr;
+  int res, fd;
+  char path[UNIX_PATH_MAX];
+
+  res = xsnprintf (path, UNIX_PATH_MAX, "%s/gdb_ust%d", P_tmpdir, pid);
+  if (res >= UNIX_PATH_MAX)
+    return -1;
+
+  res = fd = gdb_socket_cloexec (PF_UNIX, SOCK_STREAM, 0);
+  if (res == -1)
+    {
+      warning (_("error opening sync socket: %s"), safe_strerror (errno));
+      return -1;
+    }
+
+  addr.sun_family = AF_UNIX;
+
+  res = xsnprintf (addr.sun_path, UNIX_PATH_MAX, "%s", path);
+  if (res >= UNIX_PATH_MAX)
+    {
+      warning (_("string overflow allocating socket name"));
+      close (fd);
+      return -1;
+    }
+
+  res = connect (fd, (struct sockaddr *) &addr, sizeof (addr));
+  if (res == -1)
+    {
+      warning (_("error connecting sync socket (%s): %s. "
+		 "Make sure the directory exists and that it is writable."),
+		 path, safe_strerror (errno));
+      close (fd);
+      return -1;
+    }
+
+  return fd;
+#else
+  return -1;
+#endif
+}
+
+/* Execute an agent command in the inferior.  PID is the value of pid of the
+   inferior.  CMD is the buffer for command.  GDB or GDBserver will store the
+   command into it and fetch the return result from CMD.  The interaction
+   between GDB/GDBserver and the agent is synchronized by a synchronization
+   socket.  Return zero if success, otherwise return non-zero.  */
+
+int
+agent_run_command (int pid, const char *cmd, int len)
+{
+  int fd;
+  int tid = agent_get_helper_thread_id ();
+  ptid_t ptid = ptid_t (pid, tid, 0);
+
+  int ret = target_write_memory (ipa_sym_addrs.addr_cmd_buf,
+				 (gdb_byte *) cmd, len);
+
+  if (ret != 0)
+    {
+      warning (_("unable to write"));
+      return -1;
+    }
+
+  DEBUG_AGENT ("agent: resumed helper thread\n");
+
+  /* Resume helper thread.  */
+  target_continue_no_signal (ptid);
+
+  fd = gdb_connect_sync_socket (pid);
+  if (fd >= 0)
+    {
+      char buf[1] = "";
+
+      DEBUG_AGENT ("agent: signalling helper thread\n");
+
+      do
+	{
+	  ret = write (fd, buf, 1);
+	} while (ret == -1 && errno == EINTR);
+
+	DEBUG_AGENT ("agent: waiting for helper thread's response\n");
+
+      do
+	{
+	  ret = read (fd, buf, 1);
+	} while (ret == -1 && errno == EINTR);
+
+      close (fd);
+
+      DEBUG_AGENT ("agent: helper thread's response received\n");
+    }
+  else
+    return -1;
+
+  /* Need to read response with the inferior stopped.  */
+  if (ptid != null_ptid)
+    {
+      /* Stop thread PTID.  */
+      DEBUG_AGENT ("agent: stop helper thread\n");
+      target_stop_and_wait (ptid);
+    }
+
+  if (fd >= 0)
+    {
+      if (target_read_memory (ipa_sym_addrs.addr_cmd_buf, (gdb_byte *) cmd,
+			      IPA_CMD_BUF_SIZE))
+	{
+	  warning (_("Error reading command response"));
+	  return -1;
+	}
+    }
+
+  return 0;
+}
+
+/* Each bit of it stands for a capability of agent.  */
+static uint32_t agent_capability = 0;
+
+/* Return true if agent has capability AGENT_CAP, otherwise return false.  */
+
+bool
+agent_capability_check (enum agent_capa agent_capa)
+{
+  if (agent_capability == 0)
+    {
+      if (target_read_uint32 (ipa_sym_addrs.addr_capability,
+			      &agent_capability))
+	warning (_("Error reading capability of agent"));
+    }
+  return (agent_capability & agent_capa) != 0;
+}
+
+/* Invalidate the cache of agent capability, so we'll read it from inferior
+   again.  Call it when launches a new program or reconnect to remote stub.  */
+
+void
+agent_capability_invalidate (void)
+{
+  agent_capability = 0;
+}