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+/* Target operations for the remote server for GDB.
+ Copyright (C) 2002-2020 Free Software Foundation, Inc.
+
+ Contributed by MontaVista Software.
+
+ 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 "tracepoint.h"
+#include "gdbsupport/byte-vector.h"
+
+process_stratum_target *the_target;
+
+int
+set_desired_thread ()
+{
+ client_state &cs = get_client_state ();
+ thread_info *found = find_thread_ptid (cs.general_thread);
+
+ current_thread = found;
+ return (current_thread != NULL);
+}
+
+/* The thread that was current before prepare_to_access_memory was
+ called. done_accessing_memory uses this to restore the previous
+ selected thread. */
+static ptid_t prev_general_thread;
+
+/* See target.h. */
+
+int
+prepare_to_access_memory (void)
+{
+ client_state &cs = get_client_state ();
+
+ /* The first thread found. */
+ struct thread_info *first = NULL;
+ /* The first stopped thread found. */
+ struct thread_info *stopped = NULL;
+ /* The current general thread, if found. */
+ struct thread_info *current = NULL;
+
+ /* Save the general thread value, since prepare_to_access_memory could change
+ it. */
+ prev_general_thread = cs.general_thread;
+
+ if (the_target->prepare_to_access_memory != NULL)
+ {
+ int res;
+
+ res = the_target->prepare_to_access_memory ();
+ if (res != 0)
+ return res;
+ }
+
+ for_each_thread (prev_general_thread.pid (), [&] (thread_info *thread)
+ {
+ if (mythread_alive (thread->id))
+ {
+ if (stopped == NULL && the_target->thread_stopped != NULL
+ && thread_stopped (thread))
+ stopped = thread;
+
+ if (first == NULL)
+ first = thread;
+
+ if (current == NULL && prev_general_thread == thread->id)
+ current = thread;
+ }
+ });
+
+ /* The thread we end up choosing. */
+ struct thread_info *thread;
+
+ /* Prefer a stopped thread. If none is found, try the current
+ thread. Otherwise, take the first thread in the process. If
+ none is found, undo the effects of
+ target->prepare_to_access_memory() and return error. */
+ if (stopped != NULL)
+ thread = stopped;
+ else if (current != NULL)
+ thread = current;
+ else if (first != NULL)
+ thread = first;
+ else
+ {
+ done_accessing_memory ();
+ return 1;
+ }
+
+ current_thread = thread;
+ cs.general_thread = ptid_of (thread);
+
+ return 0;
+}
+
+/* See target.h. */
+
+void
+done_accessing_memory (void)
+{
+ client_state &cs = get_client_state ();
+
+ if (the_target->done_accessing_memory != NULL)
+ the_target->done_accessing_memory ();
+
+ /* Restore the previous selected thread. */
+ cs.general_thread = prev_general_thread;
+ switch_to_thread (the_target, cs.general_thread);
+}
+
+int
+read_inferior_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
+{
+ int res;
+ res = (*the_target->read_memory) (memaddr, myaddr, len);
+ check_mem_read (memaddr, myaddr, len);
+ return res;
+}
+
+/* See target/target.h. */
+
+int
+target_read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
+{
+ return read_inferior_memory (memaddr, myaddr, len);
+}
+
+/* See target/target.h. */
+
+int
+target_read_uint32 (CORE_ADDR memaddr, uint32_t *result)
+{
+ return read_inferior_memory (memaddr, (gdb_byte *) result, sizeof (*result));
+}
+
+/* See target/target.h. */
+
+int
+target_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr,
+ ssize_t len)
+{
+ /* Make a copy of the data because check_mem_write may need to
+ update it. */
+ gdb::byte_vector buffer (myaddr, myaddr + len);
+ check_mem_write (memaddr, buffer.data (), myaddr, len);
+ return (*the_target->write_memory) (memaddr, buffer.data (), len);
+}
+
+ptid_t
+mywait (ptid_t ptid, struct target_waitstatus *ourstatus, int options,
+ int connected_wait)
+{
+ ptid_t ret;
+
+ if (connected_wait)
+ server_waiting = 1;
+
+ ret = target_wait (ptid, ourstatus, options);
+
+ /* We don't expose _LOADED events to gdbserver core. See the
+ `dlls_changed' global. */
+ if (ourstatus->kind == TARGET_WAITKIND_LOADED)
+ ourstatus->kind = TARGET_WAITKIND_STOPPED;
+
+ /* If GDB is connected through TCP/serial, then GDBserver will most
+ probably be running on its own terminal/console, so it's nice to
+ print there why is GDBserver exiting. If however, GDB is
+ connected through stdio, then there's no need to spam the GDB
+ console with this -- the user will already see the exit through
+ regular GDB output, in that same terminal. */
+ if (!remote_connection_is_stdio ())
+ {
+ if (ourstatus->kind == TARGET_WAITKIND_EXITED)
+ fprintf (stderr,
+ "\nChild exited with status %d\n", ourstatus->value.integer);
+ else if (ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
+ fprintf (stderr, "\nChild terminated with signal = 0x%x (%s)\n",
+ gdb_signal_to_host (ourstatus->value.sig),
+ gdb_signal_to_name (ourstatus->value.sig));
+ }
+
+ if (connected_wait)
+ server_waiting = 0;
+
+ return ret;
+}
+
+/* See target/target.h. */
+
+void
+target_stop_and_wait (ptid_t ptid)
+{
+ struct target_waitstatus status;
+ bool was_non_stop = non_stop;
+ struct thread_resume resume_info;
+
+ resume_info.thread = ptid;
+ resume_info.kind = resume_stop;
+ resume_info.sig = GDB_SIGNAL_0;
+ (*the_target->resume) (&resume_info, 1);
+
+ non_stop = true;
+ mywait (ptid, &status, 0, 0);
+ non_stop = was_non_stop;
+}
+
+/* See target/target.h. */
+
+ptid_t
+target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
+{
+ return (*the_target->wait) (ptid, status, options);
+}
+
+/* See target/target.h. */
+
+void
+target_mourn_inferior (ptid_t ptid)
+{
+ (*the_target->mourn) (find_process_pid (ptid.pid ()));
+}
+
+/* See target/target.h. */
+
+void
+target_continue_no_signal (ptid_t ptid)
+{
+ struct thread_resume resume_info;
+
+ resume_info.thread = ptid;
+ resume_info.kind = resume_continue;
+ resume_info.sig = GDB_SIGNAL_0;
+ (*the_target->resume) (&resume_info, 1);
+}
+
+/* See target/target.h. */
+
+void
+target_continue (ptid_t ptid, enum gdb_signal signal)
+{
+ struct thread_resume resume_info;
+
+ resume_info.thread = ptid;
+ resume_info.kind = resume_continue;
+ resume_info.sig = gdb_signal_to_host (signal);
+ (*the_target->resume) (&resume_info, 1);
+}
+
+/* See target/target.h. */
+
+int
+target_supports_multi_process (void)
+{
+ return (the_target->supports_multi_process != NULL ?
+ (*the_target->supports_multi_process) () : 0);
+}
+
+int
+start_non_stop (int nonstop)
+{
+ if (the_target->start_non_stop == NULL)
+ {
+ if (nonstop)
+ return -1;
+ else
+ return 0;
+ }
+
+ return (*the_target->start_non_stop) (nonstop);
+}
+
+void
+set_target_ops (process_stratum_target *target)
+{
+ the_target = XNEW (process_stratum_target);
+ memcpy (the_target, target, sizeof (*the_target));
+}
+
+/* Convert pid to printable format. */
+
+const char *
+target_pid_to_str (ptid_t ptid)
+{
+ static char buf[80];
+
+ if (ptid == minus_one_ptid)
+ xsnprintf (buf, sizeof (buf), "<all threads>");
+ else if (ptid == null_ptid)
+ xsnprintf (buf, sizeof (buf), "<null thread>");
+ else if (ptid.tid () != 0)
+ xsnprintf (buf, sizeof (buf), "Thread %d.0x%lx",
+ ptid.pid (), ptid.tid ());
+ else if (ptid.lwp () != 0)
+ xsnprintf (buf, sizeof (buf), "LWP %d.%ld",
+ ptid.pid (), ptid.lwp ());
+ else
+ xsnprintf (buf, sizeof (buf), "Process %d",
+ ptid.pid ());
+
+ return buf;
+}
+
+int
+kill_inferior (process_info *proc)
+{
+ gdb_agent_about_to_close (proc->pid);
+
+ return (*the_target->kill) (proc);
+}
+
+/* Target can do hardware single step. */
+
+int
+target_can_do_hardware_single_step (void)
+{
+ return 1;
+}
+
+/* Default implementation for breakpoint_kind_for_pc.
+
+ The default behavior for targets that don't implement breakpoint_kind_for_pc
+ is to use the size of a breakpoint as the kind. */
+
+int
+default_breakpoint_kind_from_pc (CORE_ADDR *pcptr)
+{
+ int size = 0;
+
+ gdb_assert (the_target->sw_breakpoint_from_kind != NULL);
+
+ (*the_target->sw_breakpoint_from_kind) (0, &size);
+ return size;
+}
+
+/* Define it. */
+
+target_terminal_state target_terminal::m_terminal_state
+ = target_terminal_state::is_ours;
+
+/* See target/target.h. */
+
+void
+target_terminal::init ()
+{
+ /* Placeholder needed because of fork_inferior. Not necessary on
+ GDBserver. */
+}
+
+/* See target/target.h. */
+
+void
+target_terminal::inferior ()
+{
+ /* Placeholder needed because of fork_inferior. Not necessary on
+ GDBserver. */
+}
+
+/* See target/target.h. */
+
+void
+target_terminal::ours ()
+{
+ /* Placeholder needed because of fork_inferior. Not necessary on
+ GDBserver. */
+}
+
+/* See target/target.h. */
+
+void
+target_terminal::ours_for_output (void)
+{
+ /* Placeholder. */
+}
+
+/* See target/target.h. */
+
+void
+target_terminal::info (const char *arg, int from_tty)
+{
+ /* Placeholder. */
+}