* gdbserver/remote-utils.c (write_ok): Write "OK", not "Ok", to

	match stubs and protocol spec.
	* gdbserver/remote-utils.c (remote_open): Cast to struct sockaddr
	when passing to function which expects that.

	The following changes aren't quite enough to make things work with
	LynxOS (apprently kernel problems).
	* infrun.c (wait_for_inferior): When resuming new thread, pass pid
	not -1 for remote case.
	* thread.c (info_threads_command): Give error if !target_has_stack.
	* infrun.c (start_remote): Call init_thread_list.
	* thread.c (info_threads_command): Don't call kill for remote
	debugging target.
	* target.c (normal_pid_to_str): Print "thread" not "process" for
	remote.
	* remote.c, gdbserver/*: Add 'H', 'S', and 'C' requests, 'X'
	response, and `thread' part of 'T' response.
	* gdbserver/*: If program exits, send packet to GDB before
	exiting.  Handle termination with a signal the same as exiting
	with an exitstatus.
	* remote.c: Don't try to kill program after getting an 'X'
	response.
	* infrun.c (wait_for_inferior): Add comment about kill versus mourn.

7 files changed, 360 insertions, 97 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index a8b26b4..e80e679 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,29 @@
+Wed Dec  7 14:50:54 1994  Jim Kingdon  <kingdon@deneb.cygnus.com>
+
+	* gdbserver/remote-utils.c (write_ok): Write "OK", not "Ok", to
+	match stubs and protocol spec.
+	* gdbserver/remote-utils.c (remote_open): Cast to struct sockaddr
+	when passing to function which expects that.
+
+	The following changes aren't quite enough to make things work with
+	LynxOS (apprently kernel problems).
+	* infrun.c (wait_for_inferior): When resuming new thread, pass pid
+	not -1 for remote case.
+	* thread.c (info_threads_command): Give error if !target_has_stack. 
+	* infrun.c (start_remote): Call init_thread_list.
+	* thread.c (info_threads_command): Don't call kill for remote
+	debugging target.
+	* target.c (normal_pid_to_str): Print "thread" not "process" for
+	remote.
+	* remote.c, gdbserver/*: Add 'H', 'S', and 'C' requests, 'X'
+	response, and `thread' part of 'T' response.
+	* gdbserver/*: If program exits, send packet to GDB before
+	exiting.  Handle termination with a signal the same as exiting
+	with an exitstatus.
+	* remote.c: Don't try to kill program after getting an 'X'
+	response.
+	* infrun.c (wait_for_inferior): Add comment about kill versus mourn.
+
 Thu Dec  8 12:37:38 1994  Rob Savoye  <rob@darkstar.cygnus.com>
 
 	* config/pa/tm-pro.h tm-hppap.h, hppapro.mt: Rename tm-hppap.h to
diff --git a/gdb/gdbserver/low-lynx.c b/gdb/gdbserver/low-lynx.c
index 7fee763..f3d2720 100644
--- a/gdb/gdbserver/low-lynx.c
+++ b/gdb/gdbserver/low-lynx.c
@@ -108,33 +108,57 @@ mywait (status)
   int pid;
   union wait w;
 
-  enable_async_io();
+  while (1)
+    {
+      enable_async_io();
+
+      pid = wait (&w);
+
+      disable_async_io();
 
-  pid = wait (&w);
+      if (pid != PIDGET(inferior_pid))
+	perror_with_name ("wait");
 
-  disable_async_io();
+      thread_from_wait = w.w_tid;
+      inferior_pid = BUILDPID (inferior_pid, w.w_tid);
+      printf ("mywait: pid=0x%x, thread=0x%x, inferior_pid=0x%x\n",
+	      pid, w.w_tid, inferior_pid);
+
+      if (WIFSTOPPED(w)
+	  && WSTOPSIG(w) == SIGTRAP)
+	{
+	  int realsig;
 
-  if (pid != PIDGET(inferior_pid))
-    perror_with_name ("wait");
+	  realsig = ptrace (PTRACE_GETTRACESIG, inferior_pid,
+			    (PTRACE_ARG3_TYPE)0, 0);
 
-  inferior_pid = BUILDPID (inferior_pid, w.w_tid);
+	  if (realsig == SIGNEWTHREAD)
+	    {
+	      /* Simply ignore new thread notification, as we can't do anything
+		 useful with such threads.  All ptrace calls at this point just
+		 fail for no apparent reason.  The thread will eventually get a
+		 real signal when it becomes real.  */
+	      myresume (0, 0);
+	      continue;
+	    }
+	}
+      break;
+    }
 
   if (WIFEXITED (w))
     {
-      fprintf (stderr, "\nChild exited with status %d\n", WEXITSTATUS (w));
-      fprintf (stderr, "GDBserver exiting\n");
-      exit (0);
+      *status = 'W';
+      return ((unsigned char) WEXITSTATUS (w));
     }
   else if (!WIFSTOPPED (w))
     {
-      fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
-      *status = 'T';
+      *status = 'X';
       return ((unsigned char) WTERMSIG (w));
     }
 
   fetch_inferior_registers (0);
 
-  *status = 'S';
+  *status = 'T';
   return ((unsigned char) WSTOPSIG (w));
 }
 
@@ -148,7 +172,9 @@ myresume (step, signal)
      int signal;
 {
   errno = 0;
-  ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, inferior_pid, 1, signal);
+  ptrace (step ? PTRACE_SINGLESTEP_ONE : PTRACE_CONT,
+	  BUILDPID (inferior_pid, cont_thread == -1 ? 0 : cont_thread),
+	  1, signal);
   if (errno)
     perror_with_name ("ptrace");
 }
@@ -334,7 +360,9 @@ fetch_inferior_registers (regno)
       int i;
 
       errno = 0;
-      retval = ptrace (PTRACE_GETREGS, inferior_pid, (PTRACE_ARG3_TYPE) &ec,
+      retval = ptrace (PTRACE_GETREGS,
+		       BUILDPID (inferior_pid, general_thread),
+		       (PTRACE_ARG3_TYPE) &ec,
 		       0);
       if (errno)
 	perror_with_name ("Sparc fetch_inferior_registers(ptrace)");
@@ -387,7 +415,7 @@ fetch_inferior_registers (regno)
       int i;
 
       errno = 0;
-      retval = ptrace (PTRACE_GETFPREGS, inferior_pid, (PTRACE_ARG3_TYPE) &fc,
+      retval = ptrace (PTRACE_GETFPREGS, BUILDPID (inferior_pid, general_thread), (PTRACE_ARG3_TYPE) &fc,
 		       0);
       if (errno)
 	perror_with_name ("Sparc fetch_inferior_registers(ptrace)");
@@ -446,7 +474,7 @@ store_inferior_registers (regno)
 	      8 * REGISTER_RAW_SIZE (O0_REGNUM));
 
       errno = 0;
-      retval = ptrace (PTRACE_SETREGS, inferior_pid, (PTRACE_ARG3_TYPE) &ec,
+      retval = ptrace (PTRACE_SETREGS, BUILDPID (inferior_pid, general_thread), (PTRACE_ARG3_TYPE) &ec,
 		       0);
       if (errno)
 	perror_with_name ("Sparc fetch_inferior_registers(ptrace)");
@@ -493,7 +521,7 @@ store_inferior_registers (regno)
 
 /* We read fcontext first so that we can get good values for fq_t... */
       errno = 0;
-      retval = ptrace (PTRACE_GETFPREGS, inferior_pid, (PTRACE_ARG3_TYPE) &fc,
+      retval = ptrace (PTRACE_GETFPREGS, BUILDPID (inferior_pid, general_thread), (PTRACE_ARG3_TYPE) &fc,
 		       0);
       if (errno)
 	perror_with_name ("Sparc fetch_inferior_registers(ptrace)");
@@ -504,7 +532,7 @@ store_inferior_registers (regno)
       fc.fsr = read_register (FPS_REGNUM);
 
       errno = 0;
-      retval = ptrace (PTRACE_SETFPREGS, inferior_pid, (PTRACE_ARG3_TYPE) &fc,
+      retval = ptrace (PTRACE_SETFPREGS, BUILDPID (inferior_pid, general_thread), (PTRACE_ARG3_TYPE) &fc,
 		       0);
       if (errno)
 	perror_with_name ("Sparc fetch_inferior_registers(ptrace)");
@@ -526,12 +554,12 @@ lynx_registers_addr()
   CORE_ADDR ecp;
 
   errno = 0;
-  stblock = (CORE_ADDR) ptrace (PTRACE_THREADUSER, inferior_pid,
+  stblock = (CORE_ADDR) ptrace (PTRACE_THREADUSER, BUILDPID (inferior_pid, general_thread),
 				(PTRACE_ARG3_TYPE)0, 0);
   if (errno)
     perror_with_name ("PTRACE_THREADUSER");
 
-  ecp = (CORE_ADDR) ptrace (PTRACE_PEEKTHREAD, inferior_pid,
+  ecp = (CORE_ADDR) ptrace (PTRACE_PEEKTHREAD, BUILDPID (inferior_pid, general_thread),
 			    (PTRACE_ARG3_TYPE)ecpoff, 0);
   if (errno)
     perror_with_name ("lynx_registers_addr(PTRACE_PEEKTHREAD)");
@@ -562,7 +590,7 @@ fetch_inferior_registers (ignored)
 #endif
 
       errno = 0;
-      reg = ptrace (ptrace_fun, inferior_pid,
+      reg = ptrace (ptrace_fun, BUILDPID (inferior_pid, general_thread),
 		    (PTRACE_ARG3_TYPE) (ecp + regmap[regno]), 0);
       if (errno)
 	perror_with_name ("fetch_inferior_registers(PTRACE_PEEKTHREAD)");
@@ -596,7 +624,7 @@ store_inferior_registers (ignored)
       reg = *(unsigned long *)&registers[REGISTER_BYTE (regno)];
 
       errno = 0;
-      ptrace (ptrace_fun, inferior_pid,
+      ptrace (ptrace_fun, BUILDPID (inferior_pid, general_thread),
 	      (PTRACE_ARG3_TYPE) (ecp + regmap[regno]), reg);
       if (errno)
 	perror_with_name ("PTRACE_POKEUSER");
@@ -632,7 +660,7 @@ read_inferior_memory (memaddr, myaddr, len)
   /* Read all the longwords */
   for (i = 0; i < count; i++, addr += sizeof (int))
     {
-      buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid, addr, 0);
+      buffer[i] = ptrace (PTRACE_PEEKTEXT, BUILDPID (inferior_pid, general_thread), addr, 0);
     }
 
   /* Copy appropriate bytes out of the buffer.  */
@@ -662,12 +690,12 @@ write_inferior_memory (memaddr, myaddr, len)
 
   /* Fill start and end extra bytes of buffer with existing memory data.  */
 
-  buffer[0] = ptrace (PTRACE_PEEKTEXT, inferior_pid, addr, 0);
+  buffer[0] = ptrace (PTRACE_PEEKTEXT, BUILDPID (inferior_pid, general_thread), addr, 0);
 
   if (count > 1)
     {
       buffer[count - 1]
-	= ptrace (PTRACE_PEEKTEXT, inferior_pid,
+	= ptrace (PTRACE_PEEKTEXT, BUILDPID (inferior_pid, general_thread),
 		  addr + (count - 1) * sizeof (int), 0);
     }
 
@@ -682,10 +710,13 @@ write_inferior_memory (memaddr, myaddr, len)
       while (1)
 	{
 	  errno = 0;
-	  ptrace (PTRACE_POKETEXT, inferior_pid, addr, buffer[i]);
+	  ptrace (PTRACE_POKETEXT, BUILDPID (inferior_pid, general_thread), addr, buffer[i]);
 	  if (errno)
 	    {
-	      fprintf(stderr, "ptrace (PTRACE_POKETEXT): errno=%d, inferior_pid=0x%x, addr=0x%x, buffer[i] = 0x%x\n", errno, inferior_pid, addr, buffer[i]);
+	      fprintf(stderr, "\
+ptrace (PTRACE_POKETEXT): errno=%d, pid=0x%x, addr=0x%x, buffer[i] = 0x%x\n",
+		      errno, BUILDPID (inferior_pid, general_thread),
+		      addr, buffer[i]);
 	      fprintf(stderr, "Sleeping for 1 second\n");
 	      sleep(1);
 	    }
diff --git a/gdb/gdbserver/low-sparc.c b/gdb/gdbserver/low-sparc.c
index 92a23ac..f3e3b0e 100644
--- a/gdb/gdbserver/low-sparc.c
+++ b/gdb/gdbserver/low-sparc.c
@@ -114,19 +114,19 @@ mywait (status)
   if (WIFEXITED (w))
     {
       fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
-      *status = 'E';
+      *status = 'W';
       return ((unsigned char) WEXITSTATUS (w));
     }
   else if (!WIFSTOPPED (w))
     {
       fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
-      *status = 'T';
+      *status = 'X';
       return ((unsigned char) WTERMSIG (w));
     }
 
   fetch_inferior_registers (0);
 
-  *status = 'S';
+  *status = 'T';
   return ((unsigned char) WSTOPSIG (w));
 }
 
diff --git a/gdb/gdbserver/low-sun3.c b/gdb/gdbserver/low-sun3.c
index b61f90e..21207e6 100644
--- a/gdb/gdbserver/low-sun3.c
+++ b/gdb/gdbserver/low-sun3.c
@@ -111,19 +111,19 @@ mywait (status)
   if (WIFEXITED (w))
     {
       fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
-      *status = 'E';
+      *status = 'W';
       return ((unsigned char) WEXITSTATUS (w));
     }
   else if (!WIFSTOPPED (w))
     {
       fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
-      *status = 'T';
+      *status = 'X';
       return ((unsigned char) WTERMSIG (w));
     }
 
   fetch_inferior_registers (0);
 
-  *status = 'S';
+  *status = 'T';
   return ((unsigned char) WSTOPSIG (w));
 }
 
diff --git a/gdb/infrun.c b/gdb/infrun.c
index fd3bf0a..850f88f 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -43,26 +43,22 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 
 /* Prototypes for local functions */
 
-static void
-signals_info PARAMS ((char *, int));
+static void signals_info PARAMS ((char *, int));
 
-static void
-handle_command PARAMS ((char *, int));
+static void handle_command PARAMS ((char *, int));
 
 static void sig_print_info PARAMS ((enum target_signal));
 
-static void
-sig_print_header PARAMS ((void));
+static void sig_print_header PARAMS ((void));
 
-static void
-resume_cleanups PARAMS ((int));
+static void resume_cleanups PARAMS ((int));
 
-static int
-hook_stop_stub PARAMS ((char *));
+static int hook_stop_stub PARAMS ((char *));
 
 /* GET_LONGJMP_TARGET returns the PC at which longjmp() will resume the
    program.  It needs to examine the jmp_buf argument and extract the PC
    from it.  The return value is non-zero on success, zero otherwise. */
+
 #ifndef GET_LONGJMP_TARGET
 #define GET_LONGJMP_TARGET(PC_ADDR) 0
 #endif
@@ -71,15 +67,24 @@ hook_stop_stub PARAMS ((char *));
 /* Some machines have trampoline code that sits between function callers
    and the actual functions themselves.  If this machine doesn't have
    such things, disable their processing.  */
+
 #ifndef SKIP_TRAMPOLINE_CODE
 #define	SKIP_TRAMPOLINE_CODE(pc)	0
 #endif
 
 /* For SVR4 shared libraries, each call goes through a small piece of
-   trampoline code in the ".plt" section.  IN_SOLIB_TRAMPOLINE evaluates
+   trampoline code in the ".plt" section.  IN_SOLIB_CALL_TRAMPOLINE evaluates
    to nonzero if we are current stopped in one of these. */
-#ifndef IN_SOLIB_TRAMPOLINE
-#define IN_SOLIB_TRAMPOLINE(pc,name)	0
+
+#ifndef IN_SOLIB_CALL_TRAMPOLINE
+#define IN_SOLIB_CALL_TRAMPOLINE(pc,name)	0
+#endif
+
+/* In some shared library schemes, the return path from a shared library
+   call may need to go through a trampoline too.  */
+
+#ifndef IN_SOLIB_RETURN_TRAMPOLINE
+#define IN_SOLIB_RETURN_TRAMPOLINE(pc,name)	0
 #endif
 
 /* On some systems, the PC may be left pointing at an instruction that  won't
@@ -371,6 +376,7 @@ static char *prev_func_name;
 void
 start_remote ()
 {
+  init_thread_list ();
   init_wait_for_inferior ();
   clear_proceed_status ();
   stop_soon_quietly = 1;
@@ -522,7 +528,14 @@ wait_for_inferior ()
 	  stop_signal = w.value.sig;
 	  target_terminal_ours ();	/* Must do this before mourn anyway */
 	  annotate_signalled ();
+
+	  /* This looks pretty bogus to me.  Doesn't TARGET_WAITKIND_SIGNALLED
+	     mean it is already dead?  This has been here since GDB 2.8, so
+	     perhaps it means rms didn't understand unix waitstatuses?
+	     For the moment I'm just kludging around this in remote.c
+	     rather than trying to change it here --kingdon, 5 Dec 1994.  */
 	  target_kill ();		/* kill mourns as well */
+
 	  printf_filtered ("\nProgram terminated with signal ");
 	  annotate_signal_name ();
 	  printf_filtered ("%s", target_signal_to_name (stop_signal));
@@ -1142,7 +1155,7 @@ wait_for_inferior ()
 		 call.  I'm not completely sure this is necessary now that we
 		 have the above checks with stop_func_start (and now that
 		 find_pc_partial_function is pickier).  */
-	      || IN_SOLIB_TRAMPOLINE (stop_pc, stop_func_name)
+	      || IN_SOLIB_CALL_TRAMPOLINE (stop_pc, stop_func_name)
 
 	      /* If none of the above apply, it is a jump within a function,
 		 or a return from a subroutine.  The other case is longjmp,
@@ -1280,6 +1293,38 @@ step_into_function:
 	  break;
 	}
 
+      /* If we're in the return path from a shared library trampoline,
+	 we want to proceed through the trampoline when stepping.  */
+      if (IN_SOLIB_RETURN_TRAMPOLINE(stop_pc, stop_func_name))
+	{
+	  CORE_ADDR tmp;
+
+	  /* Determine where this trampoline returns.  */
+	  tmp = SKIP_TRAMPOLINE_CODE (stop_pc);
+
+	  /* Only proceed through if we know where it's going.  */
+	  if (tmp)
+	    {
+	      /* And put the step-breakpoint there and go until there. */
+	      struct symtab_and_line sr_sal;
+
+	      sr_sal.pc = tmp;
+	      sr_sal.symtab = NULL;
+	      sr_sal.line = 0;
+	      /* Do not specify what the fp should be when we stop
+		 since on some machines the prologue
+		 is where the new fp value is established.  */
+	      step_resume_breakpoint =
+		set_momentary_breakpoint (sr_sal, NULL, bp_step_resume);
+	      if (breakpoints_inserted)
+		insert_breakpoints ();
+
+	      /* Restart without fiddling with the step ranges or
+		 other state.  */
+	      goto keep_going;
+	    }
+	}
+	 
       if (sal.line == 0)
 	{
 	  /* We have no line number information.  That means to stop
@@ -1885,7 +1930,7 @@ save_inferior_status (inf_status, restore_stack_info)
 }
 
 struct restore_selected_frame_args {
-  FRAME_ADDR frame_address;
+  CORE_ADDR frame_address;
   int level;
 };
 
@@ -1895,27 +1940,28 @@ static int restore_selected_frame PARAMS ((char *));
    restore_selected_frame_args * (declared as char * for catch_errors)
    telling us what frame to restore.  Returns 1 for success, or 0 for
    failure.  An error message will have been printed on error.  */
+
 static int
 restore_selected_frame (args)
      char *args;
 {
   struct restore_selected_frame_args *fr =
     (struct restore_selected_frame_args *) args;
-  FRAME fid;
+  struct frame_info *frame;
   int level = fr->level;
 
-  fid = find_relative_frame (get_current_frame (), &level);
+  frame = find_relative_frame (get_current_frame (), &level);
 
   /* If inf_status->selected_frame_address is NULL, there was no
      previously selected frame.  */
-  if (fid == 0 ||
-      FRAME_FP (fid) != fr->frame_address ||
+  if (frame == NULL ||
+      FRAME_FP (frame) != fr->frame_address ||
       level != 0)
     {
       warning ("Unable to restore previously selected frame.\n");
       return 0;
     }
-  select_frame (fid, fr->level);
+  select_frame (frame, fr->level);
   return(1);
 }
 
diff --git a/gdb/remote.c b/gdb/remote.c
index 942f1bd..7349305 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -38,10 +38,21 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 	-	- if CSUM is incorrect
 
    <data> is as follows:
-   All values are encoded in ascii hex digits.
+   Most values are encoded in ascii hex digits.  Signal numbers are according
+   to the numbering in target.h.
 
 	Request		Packet
 
+	set thread	Hct...		Set thread for subsequent operations.
+					c = 'c' for thread used in step and 
+					continue; t... can be -1 for all
+					threads.
+					c = 'g' for thread used in other
+					operations.  If zero, pick a thread,
+					any thread.
+	reply		OK		for success
+			ENN		for an error.
+
 	read registers  g
 	reply		XX....X		Each byte of register data
 					is described by two hex digits.
@@ -78,7 +89,7 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 					where only part of the data was
 					written).
 
-	cont		cAA..AA		AA..AA is address to resume
+	continue	cAA..AA		AA..AA is address to resume
 					If AA..AA is omitted,
 					resume at same address.
 
@@ -86,6 +97,12 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 					If AA..AA is omitted,
 					resume at same address.
 
+	continue with	Csig;AA		Continue with signal sig (hex signal
+	signal				number).
+
+	step with	Ssig;AA		Like 'C' but step not continue.
+	signal
+
 	last signal     ?               Reply the current reason for stopping.
                                         This is the same reply as is generated
 					for step or cont : SAA where AA is the
@@ -93,16 +110,31 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 
 	There is no immediate reply to step or cont.
 	The reply comes when the machine stops.
-	It is		SAA		AA is the "signal number"
+	It is		SAA		AA is the signal number.
 
-	or...		TAAn...:r...;n:r...;n...:r...;
+	or...		TAAn...:r...;n...:r...;n...:r...;
 					AA = signal number
-					n... = register number
-					r... = register contents
+					n... = register number (hex)
+					  r... = register contents
+					n... = `thread'
+					  r... = thread process ID.  This is
+						 a hex integer.
+					n... = other string not starting 
+					    with valid hex digit.
+					  gdb should ignore this n,r pair
+					  and go on to the next.  This way
+					  we can extend the protocol.
 	or...		WAA		The process exited, and AA is
 					the exit status.  This is only
 					applicable for certains sorts of
 					targets.
+	or...		XAA		The process terminated with signal
+					AA.
+	or...         	Otext		Send text to stdout.  This can happen
+					at any time while the program is
+					running and the debugger should
+					continue to wait for 'W', 'T', etc.
+
 	kill request	k
 
 	toggle debug	d		toggle debug flag (see 386 & 68k stubs)
@@ -122,8 +154,6 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 	general set	QXXXX=yyyy	Set value of XXXX to yyyy.
 	query sect offs	qOffsets	Get section offsets.  Reply is
 					Text=xxx;Data=yyy;Bss=zzz
-	console output	Otext		Send text to stdout.  Only comes from
-					remote target.
 
 	Responses can be run-length encoded to save space.  A '*' means that
 	the next character is an ASCII encoding giving a repeat count which
@@ -196,7 +226,7 @@ remote_store_registers PARAMS ((int regno));
 static void
 getpkt PARAMS ((char *buf, int forever));
 
-static void
+static int
 putpkt PARAMS ((char *buf));
 
 static void
@@ -267,6 +297,39 @@ serial_t remote_desc = NULL;
 static int stub_supports_P = 1;
 
 
+/* These are the threads which we last sent to the remote system.  -1 for all
+   or -2 for not sent yet.  */
+int general_thread;
+int cont_thread;
+
+static void
+set_thread (th, gen)
+     int th;
+     int gen;
+{
+  char buf[PBUFSIZ];
+  int state = gen ? general_thread : cont_thread;
+  if (state == th)
+    return;
+  buf[0] = 'H';
+  buf[1] = gen ? 'g' : 'c';
+  if (th == 42000)
+    {
+      buf[2] = '0';
+      buf[3] = '\0';
+    }
+  else if (th < 0)
+    sprintf (&buf[2], "-%x", -th);
+  else
+    sprintf (&buf[2], "%x", th);
+  putpkt (buf);
+  getpkt (buf, 0);
+  if (gen)
+    general_thread = th;
+  else
+    cont_thread = th;
+}
+
 /* Clean up connection to a remote debugger.  */
 
 /* ARGSUSED */
@@ -348,6 +411,9 @@ remote_start_remote (dummy)
 
   SERIAL_WRITE (remote_desc, "+", 1);
 
+  /* Let the stub know that we want it to return the thread.  */
+  set_thread (-1, 0);
+
   get_offsets ();		/* Get text, data & bss offsets */
 
   putpkt ("?");			/* initiate a query from remote machine */
@@ -411,6 +477,9 @@ device is attached to the remote system (e.g. /dev/ttya).");
      stub to another, we can (if the target is closed and reopened) cope.  */
   stub_supports_P = 1;
 
+  general_thread = -2;
+  cont_thread = -2;
+
   /* Without this, some commands which require an active target (such as kill)
      won't work.  This variable serves (at least) double duty as both the pid
      of the target process (if it has such), and as a flag indicating that a
@@ -477,6 +546,9 @@ tohex (nib)
 
 /* Tell the remote machine to resume.  */
 
+static enum target_signal last_sent_signal = TARGET_SIGNAL_0;
+int last_sent_step;
+
 static void
 remote_resume (pid, step, siggnal)
      int pid, step;
@@ -484,18 +556,25 @@ remote_resume (pid, step, siggnal)
 {
   char buf[PBUFSIZ];
 
-  if (siggnal)
-    {
-      target_terminal_ours_for_output ();
-      printf_filtered
-	("Can't send signals to a remote system.  %s not sent.\n",
-	 target_signal_to_name (siggnal));
-      target_terminal_inferior ();
-    }
+  if (pid == -1)
+    set_thread (inferior_pid, 0);
+  else
+    set_thread (pid, 0);
 
   dcache_flush (remote_dcache);
 
-  strcpy (buf, step ? "s": "c");
+  last_sent_signal = siggnal;
+  last_sent_step = step;
+
+  if (siggnal != TARGET_SIGNAL_0)
+    {
+      buf[0] = step ? 'S' : 'C';
+      buf[1] = tohex (((int)siggnal >> 4) & 0xf);
+      buf[2] = tohex ((int)siggnal & 0xf);
+      buf[3] = '\0';
+    }
+  else
+    strcpy (buf, step ? "s": "c");
 
   putpkt (buf);
 }
@@ -547,6 +626,9 @@ Give up (and stop debugging it)? "))
   target_terminal_inferior ();
 }
 
+/* If nonzero, ignore the next kill.  */
+int kill_kludge;
+
 /* Wait until the remote machine stops, then return,
    storing status in STATUS just as `wait' would.
    Returns "pid" (though it's not clear what, if anything, that
@@ -558,6 +640,7 @@ remote_wait (pid, status)
      struct target_waitstatus *status;
 {
   unsigned char buf[PBUFSIZ];
+  int thread_num = -1;
 
   status->kind = TARGET_WAITKIND_EXITED;
   status->value.integer = 0;
@@ -597,31 +680,44 @@ remote_wait (pid, status)
 		regno = strtol (p, &p1, 16); /* Read the register number */
 
 		if (p1 == p)
-		  warning ("Remote sent badly formed register number: %s\nPacket: '%s'\n",
-			   p1, buf);
-
-		p = p1;
-
-		if (*p++ != ':')
-		  warning ("Malformed packet (missing colon): %s\nPacket: '%s'\n",
-			   p, buf);
-
-		if (regno >= NUM_REGS)
-		  warning ("Remote sent bad register number %d: %s\nPacket: '%s'\n",
-			   regno, p, buf);
-
-		for (i = 0; i < REGISTER_RAW_SIZE (regno); i++)
 		  {
-		    if (p[0] == 0 || p[1] == 0)
-		      warning ("Remote reply is too short: %s", buf);
-		    regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
-		    p += 2;
+		    p1 = (unsigned char *) strchr (p, ':');
+		    if (p1 == NULL)
+		      warning ("Malformed packet (missing colon): %s\n\
+Packet: '%s'\n",
+			       p, buf);
+		    if (strncmp (p, "thread", p1 - p) == 0)
+		      {
+			char *p2;
+			thread_num = strtol (++p1, &p, 16);
+		      }
+		  }
+		else
+		  {
+		    p = p1;
+
+		    if (*p++ != ':')
+		      warning ("Malformed packet (missing colon): %s\n\
+Packet: '%s'\n",
+			       p, buf);
+
+		    if (regno >= NUM_REGS)
+		      warning ("Remote sent bad register number %d: %s\n\
+Packet: '%s'\n",
+			       regno, p, buf);
+
+		    for (i = 0; i < REGISTER_RAW_SIZE (regno); i++)
+		      {
+			if (p[0] == 0 || p[1] == 0)
+			  warning ("Remote reply is too short: %s", buf);
+			regs[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
+			p += 2;
+		      }
+		    supply_register (regno, regs);
 		  }
 
 		if (*p++ != ';')
 		  warning ("Remote register badly formatted: %s", buf);
-
-		supply_register (regno, regs);
 	      }
 	  }
 	  /* fall through */
@@ -630,22 +726,60 @@ remote_wait (pid, status)
 	  status->value.sig = (enum target_signal)
 	    (((fromhex (buf[1])) << 4) + (fromhex (buf[2])));
 
-	  return inferior_pid;
+	  goto got_status;
 	case 'W':		/* Target exited */
 	  {
 	    /* The remote process exited.  */
 	    status->kind = TARGET_WAITKIND_EXITED;
 	    status->value.integer = (fromhex (buf[1]) << 4) + fromhex (buf[2]);
-	    return inferior_pid;
+	    goto got_status;
 	  }
+	case 'X':
+	  status->kind = TARGET_WAITKIND_SIGNALLED;
+	  status->value.sig = (enum target_signal)
+	    (((fromhex (buf[1])) << 4) + (fromhex (buf[2])));
+	  kill_kludge = 1;
+
+	  goto got_status;
 	case 'O':		/* Console output */
 	  fputs_filtered ((char *)(buf + 1), gdb_stdout);
 	  continue;
+	case '\0':
+	  if (last_sent_signal != TARGET_SIGNAL_0)
+	    {
+	      /* Zero length reply means that we tried 'S' or 'C' and
+		 the remote system doesn't support it.  */
+	      target_terminal_ours_for_output ();
+	      printf_filtered
+		("Can't send signals to this remote system.  %s not sent.\n",
+		 target_signal_to_name (last_sent_signal));
+	      last_sent_signal = TARGET_SIGNAL_0;
+	      target_terminal_inferior ();
+
+	      strcpy (buf, last_sent_step ? 's' : 'c');
+	      putpkt (buf);
+	      continue;
+	    }
+	  /* else fallthrough */
 	default:
 	  warning ("Invalid remote reply: %s", buf);
 	  continue;
 	}
     }
+ got_status:
+  if (thread_num != -1)
+    {
+      /* Initial thread value can only be acquired via wait, so deal with
+	 this marker which is used before the first thread value is
+	 acquired.  */
+      if (inferior_pid == 42000)
+	{
+	  inferior_pid = thread_num;
+	  add_thread (inferior_pid);
+	}
+      return thread_num;
+    }
+  return inferior_pid;
 }
 
 /* Number of bytes of registers this stub implements.  */
@@ -663,6 +797,8 @@ remote_fetch_registers (regno)
   char *p;
   char regs[REGISTER_BYTES];
 
+  set_thread (inferior_pid, 1);
+
   sprintf (buf, "g");
   remote_send (buf);
 
@@ -736,6 +872,8 @@ remote_store_registers (regno)
   int i;
   char *p;
 
+  set_thread (inferior_pid, 1);
+
   if (regno >= 0 && stub_supports_P)
     {
       /* Try storing a single register.  */
@@ -944,6 +1082,8 @@ remote_xfer_memory(memaddr, myaddr, len, should_write, target)
   int bytes_xferred;
   int total_xferred = 0;
 
+  set_thread (inferior_pid, 1);
+
   while (len > 0)
     {
       if (len > MAXBUFBYTES)
@@ -1096,7 +1236,7 @@ remote_send (buf)
 /* Send a packet to the remote machine, with error checking.
    The data of the packet is in BUF.  */
 
-static void
+static int
 putpkt (buf)
      char *buf;
 {
@@ -1165,7 +1305,7 @@ putpkt (buf)
 	    case '+':
 	      if (remote_debug)
 		printf_unfiltered("Ack\n");
-	      return;
+	      return 1;
 	    case SERIAL_TIMEOUT:
 	      break;		/* Retransmit buffer */
 	    case '$':
@@ -1367,7 +1507,19 @@ retry:
 static void
 remote_kill ()
 {
-  putpkt ("k");
+  /* For some mysterious reason, wait_for_inferior calls kill instead of
+     mourn after it gets TARGET_WAITKIND_SIGNALLED.  Work around it.  */
+  if (kill_kludge)
+    {
+      kill_kludge = 0;
+      target_mourn_inferior ();
+      return;
+    }
+
+  /* Use catch_errors so the user can quit from gdb even when we aren't on
+     speaking terms with the remote system.  */
+  catch_errors (putpkt, "k", "", RETURN_MASK_ERROR);
+
   /* Don't wait for it to die.  I'm not really sure it matters whether
      we do or not.  For the existing stubs, kill is a noop.  */
   target_mourn_inferior ();
diff --git a/gdb/thread.c b/gdb/thread.c
index db0bbbf..0f6e67c 100644
--- a/gdb/thread.c
+++ b/gdb/thread.c
@@ -170,9 +170,17 @@ info_threads_command (arg, from_tty)
   struct thread_info *tp;
   int current_pid = inferior_pid;
 
+  /* Avoid coredumps which would happen if we tried to access a NULL
+     selected_frame.  */
+  if (!target_has_stack) error ("No stack.");
+
   for (tp = thread_list; tp; tp = tp->next)
     {
-      if (target_has_execution
+      /* FIXME: need to figure out a way to do this for remote too,
+	 or else the print_stack_frame below will fail with a bogus
+	 thread ID.  */
+      if (!STREQ (current_target.to_shortname, "remote")
+	  && target_has_execution
 	  && kill (tp->pid, 0) == -1)
  	{
 	  tp->pid = -1;	/* Mark it as dead */