Initial revision

1 files changed, 4646 insertions, 0 deletions

diff --git a/gdb/m3-nat.c b/gdb/m3-nat.c
new file mode 100644
index 00000000000..4614f656550
--- /dev/null
+++ b/gdb/m3-nat.c
@@ -0,0 +1,4646 @@
+/* Interface GDB to Mach 3.0 operating systems.
+   (Most) Mach 3.0 related routines live in this file.
+
+   Copyright (C) 1992, 1996, 1999 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 2 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, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/*
+ * Author: Jukka Virtanen <jtv@hut.fi>
+ *	   Computing Centre
+ *         Helsinki University of Technology
+ *         Finland
+ *
+ * Thanks to my friends who helped with ideas and testing:
+ *
+ *	Johannes Helander, Antti Louko, Tero Mononen,
+ *	jvh@cs.hut.fi	   alo@hut.fi   tmo@cs.hut.fi
+ *
+ *      Tero Kivinen       and          Eamonn McManus
+ *	kivinen@cs.hut.fi               emcmanus@gr.osf.org
+ *	
+ */
+
+#include <stdio.h>
+
+#include <mach.h>
+#include <servers/netname.h>
+#include <servers/machid.h>
+#include <mach/message.h>
+#include <mach/notify.h>
+#include <mach_error.h>
+#include <mach/exception.h>
+#include <mach/vm_attributes.h>
+
+#include "defs.h"
+#include "inferior.h"
+#include "symtab.h"
+#include "value.h"
+#include "language.h"
+#include "target.h"
+#include "wait.h"
+#include "gdbcmd.h"
+#include "gdbcore.h"
+
+#if 0
+#include <servers/machid_lib.h>
+#else
+#define	MACH_TYPE_TASK			1
+#define MACH_TYPE_THREAD		2
+#endif
+
+/* Included only for signal names and NSIG
+ *
+ * note: There are many problems in signal handling with
+ *       gdb in Mach 3.0 in general.
+ */
+#include <signal.h>
+#define SIG_UNKNOWN 0	/* Exception that has no matching unix signal */
+
+#include <cthreads.h>
+
+/* This is what a cproc looks like.  This is here partly because
+   cthread_internals.h is not a header we can just #include, partly with
+   an eye towards perhaps getting this to work with cross-debugging
+   someday.  Best solution is if CMU publishes a real interface to this
+   stuff.  */
+#define CPROC_NEXT_OFFSET 0
+#define CPROC_NEXT_SIZE (TARGET_PTR_BIT / HOST_CHAR_BIT)
+#define CPROC_INCARNATION_OFFSET (CPROC_NEXT_OFFSET + CPROC_NEXT_SIZE)
+#define CPROC_INCARNATION_SIZE (sizeof (cthread_t))
+#define CPROC_LIST_OFFSET (CPROC_INCARNATION_OFFSET + CPROC_INCARNATION_SIZE)
+#define CPROC_LIST_SIZE (TARGET_PTR_BIT / HOST_CHAR_BIT)
+#define CPROC_WAIT_OFFSET (CPROC_LIST_OFFSET + CPROC_LIST_SIZE)
+#define CPROC_WAIT_SIZE (TARGET_PTR_BIT / HOST_CHAR_BIT)
+#define CPROC_REPLY_OFFSET (CPROC_WAIT_OFFSET + CPROC_WAIT_SIZE)
+#define CPROC_REPLY_SIZE (sizeof (mach_port_t))
+#define CPROC_CONTEXT_OFFSET (CPROC_REPLY_OFFSET + CPROC_REPLY_SIZE)
+#define CPROC_CONTEXT_SIZE (TARGET_INT_BIT / HOST_CHAR_BIT)
+#define CPROC_LOCK_OFFSET (CPROC_CONTEXT_OFFSET + CPROC_CONTEXT_SIZE)
+#define CPROC_LOCK_SIZE (sizeof (spin_lock_t))
+#define CPROC_STATE_OFFSET (CPROC_LOCK_OFFSET + CPROC_LOCK_SIZE)
+#define CPROC_STATE_SIZE (TARGET_INT_BIT / HOST_CHAR_BIT)
+#define CPROC_WIRED_OFFSET (CPROC_STATE_OFFSET + CPROC_STATE_SIZE)
+#define CPROC_WIRED_SIZE (sizeof (mach_port_t))
+#define CPROC_BUSY_OFFSET (CPROC_WIRED_OFFSET + CPROC_WIRED_SIZE)
+#define CPROC_BUSY_SIZE (TARGET_INT_BIT / HOST_CHAR_BIT)
+#define CPROC_MSG_OFFSET (CPROC_BUSY_OFFSET + CPROC_BUSY_SIZE)
+#define CPROC_MSG_SIZE (sizeof (mach_msg_header_t))
+#define CPROC_BASE_OFFSET (CPROC_MSG_OFFSET + CPROC_MSG_SIZE)
+#define CPROC_BASE_SIZE (TARGET_INT_BIT / HOST_CHAR_BIT)
+#define CPROC_SIZE_OFFSET (CPROC_BASE_OFFSET + CPROC_BASE_SIZE)
+#define CPROC_SIZE_SIZE (TARGET_INT_BIT / HOST_CHAR_BIT)
+#define CPROC_SIZE (CPROC_SIZE_OFFSET + CPROC_SIZE_SIZE)
+
+/* Values for the state field in the cproc.  */
+#define CPROC_RUNNING	0
+#define CPROC_SWITCHING 1
+#define CPROC_BLOCKED	2
+#define CPROC_CONDWAIT	4
+
+/* For cproc and kernel thread mapping */
+typedef struct gdb_thread {
+  mach_port_t	name;
+  CORE_ADDR	sp;
+  CORE_ADDR	pc;
+  CORE_ADDR	fp;
+  boolean_t     in_emulator;
+  int		slotid;
+
+  /* This is for the mthreads list.  It points to the cproc list.
+     Perhaps the two lists should be merged (or perhaps it was a mistake
+     to make them both use a struct gdb_thread).  */
+  struct gdb_thread *cproc;
+
+  /* These are for the cproc list, which is linked through the next field
+     of the struct gdb_thread.  */
+  char raw_cproc[CPROC_SIZE];
+  /* The cthread which is pointed to by the incarnation field from the
+     cproc.  This points to the copy we've read into GDB.  */
+  cthread_t cthread;
+  /* Point back to the mthreads list.  */
+  int reverse_map;
+  struct gdb_thread *next;
+} *gdb_thread_t;
+
+/* 
+ * Actions for Mach exceptions.
+ *
+ * sigmap field maps the exception to corresponding Unix signal.
+ *
+ * I do not know how to map the exception to unix signal
+ * if SIG_UNKNOWN is specified.
+ */
+
+struct exception_list {
+  char *name;
+  boolean_t forward;
+  boolean_t print;
+  int       sigmap;
+} exception_map[] = {
+  {"not_mach3_exception",	FALSE, TRUE,  SIG_UNKNOWN},
+  {"EXC_BAD_ACCESS",		FALSE, TRUE,  SIGSEGV},
+  {"EXC_BAD_INSTRUCTION",	FALSE, TRUE,  SIGILL},
+  {"EXC_ARITHMETIC",		FALSE, TRUE,  SIGFPE},
+  {"EXC_EMULATION",		FALSE, TRUE,  SIGEMT},	/* ??? */
+  {"EXC_SOFTWARE",		FALSE, TRUE,  SIG_UNKNOWN},
+  {"EXC_BREAKPOINT",		FALSE, FALSE, SIGTRAP}
+};
+
+/* Mach exception table size */
+int max_exception = sizeof(exception_map)/sizeof(struct exception_list) - 1;
+
+#define MAX_EXCEPTION max_exception
+
+WAITTYPE wait_status;
+
+/* If you define this, intercepted bsd server calls will be
+ * dumped while waiting the inferior to EXEC the correct
+ * program
+ */
+/* #define DUMP_SYSCALL		/* debugging interceptor */
+
+/* xx_debug() outputs messages if this is nonzero.
+ * If > 1, DUMP_SYSCALL will dump message contents.
+ */
+int debug_level = 0;
+
+/* "Temporary" debug stuff */
+void
+xx_debug (fmt, a,b,c)
+char *fmt;
+int a,b,c;
+{
+  if (debug_level)
+    warning (fmt, a, b, c);
+}
+
+/* This is in libmach.a */
+extern  mach_port_t  name_server_port;
+
+/* Set in catch_exception_raise */
+int stop_exception, stop_code, stop_subcode;
+int stopped_in_exception;
+
+/* Thread that was the active thread when we stopped */
+thread_t stop_thread = MACH_PORT_NULL;
+
+char *hostname = "";
+
+/* Set when task is attached or created */
+boolean_t emulator_present = FALSE;
+
+task_t   inferior_task;
+thread_t current_thread;
+
+/* Exception ports for inferior task */
+mach_port_t inferior_exception_port     = MACH_PORT_NULL;
+mach_port_t inferior_old_exception_port = MACH_PORT_NULL;
+
+/* task exceptions and notifications */
+mach_port_t inferior_wait_port_set	= MACH_PORT_NULL;
+mach_port_t our_notify_port       	= MACH_PORT_NULL;
+
+/* This is "inferior_wait_port_set" when not single stepping, and
+ *         "singlestepped_thread_port" when we are single stepping.
+ * 
+ * This is protected by a cleanup function: discard_single_step()
+ */
+mach_port_t currently_waiting_for	= MACH_PORT_NULL;
+
+/* A port for external messages to gdb.
+ * External in the meaning that they do not come
+ * from the inferior_task, but rather from external
+ * tasks.
+ *
+ * As a debugging feature:
+ * A debugger debugging another debugger can stop the
+ * inferior debugger by the following command sequence
+ * (without running external programs)
+ *
+ *    (top-gdb) set stop_inferior_gdb ()
+ *    (top-gdb) continue
+ */
+mach_port_t our_message_port       	= MACH_PORT_NULL;
+
+/* For single stepping */
+mach_port_t thread_exception_port 	= MACH_PORT_NULL;
+mach_port_t thread_saved_exception_port = MACH_PORT_NULL;
+mach_port_t singlestepped_thread_port   = MACH_PORT_NULL;
+
+/* For machid calls */
+mach_port_t mid_server = MACH_PORT_NULL;
+mach_port_t mid_auth   = MACH_PORT_NULL;
+
+/* If gdb thinks the inferior task is not suspended, it
+ * must take suspend/abort the threads when it reads the state.
+ */
+int must_suspend_thread = 0;
+
+/* When single stepping, we switch the port that mach_really_wait() listens to.
+ * This cleanup is a guard to prevent the port set from being left to
+ * the singlestepped_thread_port when error() is called.
+ *  This is nonzero only when we are single stepping.
+ */
+#define NULL_CLEANUP (struct cleanup *)0
+struct cleanup *cleanup_step = NULL_CLEANUP;
+
+
+static struct target_ops m3_ops;
+
+static void m3_kill_inferior ();
+
+#if 0
+#define MACH_TYPE_EXCEPTION_PORT	-1
+#endif
+
+/* Chain of ports to remember requested notifications. */
+
+struct port_chain {
+  struct port_chain *next;
+  mach_port_t	     port;
+  int		     type;
+  int		     mid;  /* Now only valid with MACH_TYPE_THREAD and */
+  			   /*  MACH_TYPE_THREAD */
+};
+typedef struct port_chain *port_chain_t;
+
+/* Room for chain nodes comes from pchain_obstack */
+struct obstack pchain_obstack;
+struct obstack *port_chain_obstack = &pchain_obstack;
+
+/* For thread handling */
+struct obstack Cproc_obstack;
+struct obstack *cproc_obstack = &Cproc_obstack;
+
+/* the list of notified ports */
+port_chain_t notify_chain = (port_chain_t) NULL;
+
+port_chain_t
+port_chain_insert (list, name, type)
+     port_chain_t list;
+     mach_port_t name;
+     int	 type;
+{
+  kern_return_t ret;
+  port_chain_t new;
+  int mid;
+
+  if (! MACH_PORT_VALID (name))
+    return list;
+  
+  if (type == MACH_TYPE_TASK || type == MACH_TYPE_THREAD)
+    {
+      if (! MACH_PORT_VALID (mid_server))
+	{
+	  warning ("Machid server port invalid, can not map port 0x%x to MID",
+		   name);
+	  mid = name;
+	}
+      else
+	{
+	  ret = machid_mach_register (mid_server, mid_auth, name, type, &mid);
+	  
+	  if (ret != KERN_SUCCESS)
+	    {
+	      warning ("Can not map name (0x%x) to MID with machid", name);
+	      mid = name;
+	    }
+	}
+    }
+  else
+    abort ();
+
+  new = (port_chain_t) obstack_alloc (port_chain_obstack,
+				      sizeof (struct port_chain));
+  new->next  = list;
+  new->port  = name;
+  new->type  = type;
+  new->mid   = mid;
+
+  return new;
+}
+
+port_chain_t
+port_chain_delete (list, elem)
+     port_chain_t list;
+     mach_port_t elem;
+{
+  if (list)
+    if (list->port == elem)
+      list = list->next;
+    else
+      while (list->next)
+	{
+	  if (list->next->port == elem)
+	    list->next = list->next->next; /* GCd with obstack_free() */
+	  else
+	    list = list->next;
+	}
+  return list;
+}
+
+void
+port_chain_destroy (ostack)
+     struct obstack *ostack;
+{
+  obstack_free (ostack, 0);
+  obstack_init (ostack);
+}
+
+port_chain_t
+port_chain_member (list, elem)
+     port_chain_t list;
+     mach_port_t elem;
+{
+  while (list)
+    {
+      if (list->port == elem)
+	return list;
+      list = list->next;
+    }
+  return (port_chain_t) NULL;
+}
+
+int
+map_port_name_to_mid (name, type)
+mach_port_t name;
+int         type;
+{
+  port_chain_t elem;
+
+  if (!MACH_PORT_VALID (name))
+    return -1;
+
+  elem = port_chain_member (notify_chain, name);
+
+  if (elem && (elem->type == type))
+    return elem->mid;
+  
+  if (elem)
+    return -1;
+  
+  if (! MACH_PORT_VALID (mid_server))
+    {
+      warning ("Machid server port invalid, can not map port 0x%x to mid",
+	       name);
+      return -1;
+    }
+  else
+    {
+      int mid;
+      kern_return_t ret;
+
+      ret = machid_mach_register (mid_server, mid_auth, name, type, &mid);
+      
+      if (ret != KERN_SUCCESS)
+	{
+	  warning ("Can not map name (0x%x) to mid with machid", name);
+	  return -1;
+	}
+      return mid;
+    }
+}
+
+/* Guard for currently_waiting_for and singlestepped_thread_port */
+static void
+discard_single_step (thread)
+     thread_t thread;
+{
+  currently_waiting_for = inferior_wait_port_set;
+
+  cleanup_step = NULL_CLEANUP;
+  if (MACH_PORT_VALID (thread) && MACH_PORT_VALID (singlestepped_thread_port))
+    setup_single_step (thread, FALSE);
+}
+
+setup_single_step (thread, start_step)
+     thread_t  thread;
+     boolean_t start_step;
+{
+  kern_return_t ret;
+
+  if (! MACH_PORT_VALID (thread))
+    error ("Invalid thread supplied to setup_single_step");
+  else
+    {
+      mach_port_t teport;
+
+      /* Get the current thread exception port */
+      ret = thread_get_exception_port (thread, &teport);
+      CHK ("Getting thread's exception port", ret);
+	  
+      if (start_step)
+	{
+	  if (MACH_PORT_VALID (singlestepped_thread_port))
+	    {
+	      warning ("Singlestepped_thread_port (0x%x) is still valid?",
+		       singlestepped_thread_port);
+	      singlestepped_thread_port = MACH_PORT_NULL;
+	    }
+      
+	  /* If we are already stepping this thread */
+	  if (MACH_PORT_VALID (teport) && teport == thread_exception_port)
+	    {
+	      ret = mach_port_deallocate (mach_task_self (), teport);
+	      CHK ("Could not deallocate thread exception port", ret);
+	    }
+	  else
+	    {
+	      ret = thread_set_exception_port (thread, thread_exception_port);
+	      CHK ("Setting exception port for thread", ret);
+#if 0
+	      /* Insert thread exception port to wait port set */
+	      ret = mach_port_move_member (mach_task_self(), 
+					   thread_exception_port,
+					   inferior_wait_port_set);
+	      CHK ("Moving thread exception port to inferior_wait_port_set",
+		   ret);
+#endif
+	      thread_saved_exception_port = teport;
+	    }
+	  
+	  thread_trace (thread, TRUE);
+	  
+	  singlestepped_thread_port   = thread_exception_port;
+	  currently_waiting_for       = singlestepped_thread_port;
+	  cleanup_step = make_cleanup (discard_single_step, thread);
+	}
+      else
+	{
+	  if (! MACH_PORT_VALID (teport))
+	    error ("Single stepped thread had an invalid exception port?");
+
+	  if (teport != thread_exception_port)
+	    error ("Single stepped thread had an unknown exception port?");
+	  
+	  ret = mach_port_deallocate (mach_task_self (), teport);
+	  CHK ("Couldn't deallocate thread exception port", ret);
+#if 0
+	  /* Remove thread exception port from wait port set */
+	  ret = mach_port_move_member (mach_task_self(), 
+				       thread_exception_port,
+				       MACH_PORT_NULL);
+	  CHK ("Removing thread exception port from inferior_wait_port_set",
+	       ret);
+#endif	  
+	  /* Restore thread's old exception port */
+	  ret = thread_set_exception_port (thread,
+					   thread_saved_exception_port);
+	  CHK ("Restoring stepped thread's exception port", ret);
+	  
+	  if (MACH_PORT_VALID (thread_saved_exception_port))
+	    (void) mach_port_deallocate (mach_task_self (),
+					 thread_saved_exception_port);
+	  
+	  thread_trace (thread, FALSE);
+	  
+	  singlestepped_thread_port = MACH_PORT_NULL;
+	  currently_waiting_for = inferior_wait_port_set;
+	  if (cleanup_step)
+	    discard_cleanups (cleanup_step);
+	}
+    }
+}
+
+static
+request_notify (name, variant, type)
+     mach_port_t	name;
+     mach_msg_id_t	variant;
+     int	        type;
+{
+  kern_return_t ret;
+  mach_port_t	previous_port_dummy = MACH_PORT_NULL;
+  
+  if (! MACH_PORT_VALID (name))
+    return;
+  
+  if (port_chain_member (notify_chain, name))
+    return;
+
+  ret = mach_port_request_notification (mach_task_self(),
+					name,
+					variant,
+					1,
+					our_notify_port,
+					MACH_MSG_TYPE_MAKE_SEND_ONCE,
+					&previous_port_dummy);
+  CHK ("Serious: request_notify failed", ret);
+
+  (void) mach_port_deallocate (mach_task_self (),
+			       previous_port_dummy);
+
+  notify_chain = port_chain_insert (notify_chain, name, type);
+}
+
+reverse_msg_bits(msgp, type)
+     mach_msg_header_t	*msgp;
+     int type;
+{
+  int		rbits,lbits;
+  rbits = MACH_MSGH_BITS_REMOTE(msgp->msgh_bits);
+  lbits = type;
+  msgp->msgh_bits =
+    (msgp->msgh_bits & ~MACH_MSGH_BITS_PORTS_MASK) |
+      MACH_MSGH_BITS(lbits,rbits);
+}
+
+/* On the third day He said:
+
+   	Let this be global
+	and then it was global.
+
+   When creating the inferior fork, the
+   child code in inflow.c sets the name of the
+   bootstrap_port in its address space to this
+   variable.
+
+   The name is transferred to our address space
+   with mach3_read_inferior().
+
+   Thou shalt not do this with
+   task_get_bootstrap_port() in this task, since
+   the name in the inferior task is different than
+   the one we get.
+
+   For blessed are the meek, as they shall inherit
+   the address space.
+ */
+mach_port_t original_server_port_name = MACH_PORT_NULL;
+
+
+/* Called from inferior after FORK but before EXEC */
+static void
+m3_trace_me ()
+{
+  kern_return_t ret;
+  
+  /* Get the NAME of the bootstrap port in this task
+     so that GDB can read it */
+  ret = task_get_bootstrap_port (mach_task_self (),
+				 &original_server_port_name);
+  if (ret != KERN_SUCCESS)
+    abort ();
+  ret = mach_port_deallocate (mach_task_self (),
+			      original_server_port_name);
+  if (ret != KERN_SUCCESS)
+    abort ();
+  
+  /* Suspend this task to let the parent change my ports.
+     Resumed by the debugger */
+  ret = task_suspend (mach_task_self ());
+  if (ret != KERN_SUCCESS)
+    abort ();
+}
+
+/*
+ * Intercept system calls to Unix server.
+ * After EXEC_COUNTER calls to exec(), return.
+ *
+ * Pre-assertion:  Child is suspended. (Not verified)
+ * Post-condition: Child is suspended after EXEC_COUNTER exec() calls.
+ */
+
+void
+intercept_exec_calls (exec_counter)
+     int exec_counter;
+{
+  int terminal_initted = 0;
+
+  struct syscall_msg_t {
+    mach_msg_header_t	header;
+    mach_msg_type_t 	type;
+    char room[ 2000 ];	/* Enuff space */
+  };
+
+  struct syscall_msg_t syscall_in, syscall_out;
+
+  mach_port_t fake_server;
+  mach_port_t original_server_send;
+  mach_port_t original_exec_reply;
+  mach_port_t exec_reply;
+  mach_port_t exec_reply_send;
+  mach_msg_type_name_t acquired;
+  mach_port_t emulator_server_port_name;
+  struct task_basic_info info;
+  mach_msg_type_number_t info_count;
+
+  kern_return_t ret;
+
+  if (exec_counter <= 0)
+    return;		/* We are already set up in the correct program */
+
+  ret = mach_port_allocate(mach_task_self(), 
+			   MACH_PORT_RIGHT_RECEIVE,
+			   &fake_server);
+  CHK("create inferior_fake_server port failed", ret);
+  
+  /* Wait for inferior_task to suspend itself */
+  while(1)
+    {
+      info_count = sizeof (info);
+      ret = task_info (inferior_task,
+		       TASK_BASIC_INFO,
+		       (task_info_t)&info,
+		       &info_count);
+      CHK ("Task info", ret);
+
+      if (info.suspend_count)
+	break;
+
+      /* Note that the definition of the parameter was undefined
+       * at the time of this writing, so I just use an `ad hoc' value.
+       */
+      (void) swtch_pri (42); /* Universal Priority Value */
+    }
+
+  /* Read the inferior's bootstrap port name */
+  if (!mach3_read_inferior (&original_server_port_name,
+			    &original_server_port_name,
+			    sizeof (original_server_port_name)))
+    error ("Can't read inferior task bootstrap port name");
+
+  /* @@ BUG: If more than 1 send right GDB will FAIL!!! */
+  /*      Should get refs, and set them back when restoring */
+  /* Steal the original bsd server send right from inferior */
+  ret = mach_port_extract_right (inferior_task,
+				 original_server_port_name,
+				 MACH_MSG_TYPE_MOVE_SEND,
+				 &original_server_send,
+				 &acquired);
+  CHK("mach_port_extract_right (bsd server send)",ret);
+  
+  if (acquired != MACH_MSG_TYPE_PORT_SEND)
+    error("Incorrect right extracted, send right to bsd server excpected");
+
+  ret = mach_port_insert_right (inferior_task,
+				original_server_port_name,
+				fake_server,
+				MACH_MSG_TYPE_MAKE_SEND);
+  CHK("mach_port_insert_right (fake server send)",ret);
+
+  xx_debug ("inferior task bsd server ports set up \nfs %x, ospn %x, oss %x\n",
+	    fake_server,
+	    original_server_port_name, original_server_send);
+
+  /* A receive right to the reply generated by unix server exec() request */
+  ret = mach_port_allocate(mach_task_self(), 
+			   MACH_PORT_RIGHT_RECEIVE,
+			   &exec_reply);
+  CHK("create intercepted_reply_port port failed", ret);
+    
+  /* Pass this send right to Unix server so it replies to us after exec() */
+  ret = mach_port_extract_right (mach_task_self (),
+				 exec_reply,
+				 MACH_MSG_TYPE_MAKE_SEND_ONCE,
+				 &exec_reply_send,
+				 &acquired);
+  CHK("mach_port_extract_right (exec_reply)",ret);
+
+  if (acquired != MACH_MSG_TYPE_PORT_SEND_ONCE)
+    error("Incorrect right extracted, send once excpected for exec reply");
+
+  ret = mach_port_move_member(mach_task_self(), 
+			      fake_server,
+			      inferior_wait_port_set);
+  CHK ("Moving fake syscall port to inferior_wait_port_set", ret);
+
+  xx_debug ("syscall fake server set up, resuming inferior\n");
+  
+  ret = task_resume (inferior_task);
+  CHK("task_resume (startup)", ret);
+	
+  /* Read requests from the inferior.
+     Pass directly through everything else except exec() calls.
+   */
+  while(exec_counter > 0)
+    {
+      ret = mach_msg (&syscall_in.header,	/* header */
+		      MACH_RCV_MSG,		/* options */
+		      0,			/* send size */
+		      sizeof (struct syscall_msg_t), /* receive size */
+		      inferior_wait_port_set,        /* receive_name */
+		      MACH_MSG_TIMEOUT_NONE,
+		      MACH_PORT_NULL);
+      CHK("mach_msg (intercepted sycall)", ret);
+	    
+#ifdef DUMP_SYSCALL
+      print_msg (&syscall_in.header);
+#endif
+
+      /* ASSERT : msgh_local_port == fake_server */
+
+      if (notify_server (&syscall_in.header, &syscall_out.header))
+	error ("received a notify while intercepting syscalls");
+
+      if (syscall_in.header.msgh_id == MIG_EXEC_SYSCALL_ID)
+	{
+	  xx_debug ("Received EXEC SYSCALL, counter = %d\n", exec_counter);
+	  if (exec_counter == 1)
+	    {
+	      original_exec_reply = syscall_in.header.msgh_remote_port;
+	      syscall_in.header.msgh_remote_port = exec_reply_send;
+	    }
+
+	  if (!terminal_initted)
+	    {
+	      /* Now that the child has exec'd we know it has already set its
+		 process group.  On POSIX systems, tcsetpgrp will fail with
+		 EPERM if we try it before the child's setpgid.  */
+
+	      /* Set up the "saved terminal modes" of the inferior
+		 based on what modes we are starting it with.  */
+	      target_terminal_init ();
+
+	      /* Install inferior's terminal modes.  */
+	      target_terminal_inferior ();
+
+	      terminal_initted = 1;
+	    }
+
+	  exec_counter--;
+	}
+	    
+      syscall_in.header.msgh_local_port  = syscall_in.header.msgh_remote_port;
+      syscall_in.header.msgh_remote_port = original_server_send;
+
+      reverse_msg_bits(&syscall_in.header, MACH_MSG_TYPE_COPY_SEND);
+
+      ret = mach_msg_send (&syscall_in.header);
+      CHK ("Forwarded syscall", ret);
+    }
+	
+  ret = mach_port_move_member(mach_task_self(), 
+			      fake_server,
+			      MACH_PORT_NULL);
+  CHK ("Moving fake syscall out of inferior_wait_port_set", ret);
+
+  ret = mach_port_move_member(mach_task_self(), 
+			      exec_reply,
+			      inferior_wait_port_set);
+  CHK ("Moving exec_reply to inferior_wait_port_set", ret);
+
+  ret = mach_msg (&syscall_in.header,	/* header */
+		  MACH_RCV_MSG,		/* options */
+		  0,			/* send size */
+		  sizeof (struct syscall_msg_t),	/* receive size */
+		  inferior_wait_port_set,		/* receive_name */
+		  MACH_MSG_TIMEOUT_NONE,
+		  MACH_PORT_NULL);
+  CHK("mach_msg (exec reply)", ret);
+
+  ret = task_suspend (inferior_task);
+  CHK ("Suspending inferior after last exec", ret);
+
+  must_suspend_thread = 0;
+
+  xx_debug ("Received exec reply from bsd server, suspended inferior task\n");
+
+#ifdef DUMP_SYSCALL
+      print_msg (&syscall_in.header);
+#endif
+
+  /* Message should appear as if it came from the unix server */
+  syscall_in.header.msgh_local_port = MACH_PORT_NULL;
+
+  /*  and go to the inferior task original reply port */
+  syscall_in.header.msgh_remote_port = original_exec_reply;
+
+  reverse_msg_bits(&syscall_in.header, MACH_MSG_TYPE_MOVE_SEND_ONCE);
+
+  ret = mach_msg_send (&syscall_in.header);
+  CHK ("Forwarding exec reply to inferior", ret);
+
+  /* Garbage collect */
+  ret = mach_port_deallocate (inferior_task,
+			      original_server_port_name);
+  CHK ("deallocating fake server send right", ret);
+
+  ret = mach_port_insert_right (inferior_task,
+				original_server_port_name,
+				original_server_send,
+				MACH_MSG_TYPE_MOVE_SEND);
+  CHK ("Restoring the original bsd server send right", ret);
+
+  ret = mach_port_destroy (mach_task_self (),
+			   fake_server);
+  fake_server = MACH_PORT_DEAD;
+  CHK("mach_port_destroy (fake_server)", ret);
+
+  ret = mach_port_destroy (mach_task_self (),
+			   exec_reply);
+  exec_reply = MACH_PORT_DEAD;
+  CHK("mach_port_destroy (exec_reply)", ret);
+
+  xx_debug ("Done with exec call interception\n");
+}
+
+void
+consume_send_rights (thread_list, thread_count)
+     thread_array_t thread_list;
+     int            thread_count;
+{
+  int index;
+
+  if (!thread_count)
+    return;
+
+  for (index = 0; index < thread_count; index++)
+    {
+      /* Since thread kill command kills threads, don't check ret */
+      (void) mach_port_deallocate (mach_task_self (),
+				   thread_list [ index ]);
+    }
+}
+
+/* suspend/abort/resume a thread. */
+setup_thread (thread, what)
+     mach_port_t thread;
+     int what;
+{
+  kern_return_t ret;
+
+  if (what)
+    {
+      ret = thread_suspend (thread);
+      CHK ("setup_thread thread_suspend", ret);
+      
+      ret = thread_abort (thread);
+      CHK ("setup_thread thread_abort", ret);
+    }
+  else
+    {
+      ret = thread_resume (thread);
+      CHK ("setup_thread thread_resume", ret);
+    }
+}
+
+int
+map_slot_to_mid (slot, threads, thread_count)
+     int slot;
+     thread_array_t threads;
+     int thread_count;
+{
+  kern_return_t ret;
+  int deallocate = 0;
+  int index;
+  int mid;
+
+  if (! threads)
+    {
+      deallocate++;
+      ret = task_threads (inferior_task, &threads, &thread_count);
+      CHK ("Can not select a thread from a dead task", ret);
+    }
+  
+  if (slot < 0 || slot >= thread_count)
+    {
+      if (deallocate)
+	{
+	  consume_send_rights (threads, thread_count);
+	  (void) vm_deallocate (mach_task_self(), (vm_address_t)threads, 
+				(thread_count * sizeof(mach_port_t)));
+	}
+      if (slot < 0)
+	error ("invalid slot number");
+      else
+	return -(slot+1);
+    }
+
+  mid = map_port_name_to_mid (threads [slot], MACH_TYPE_THREAD);
+
+  if (deallocate)
+    {
+      consume_send_rights (threads, thread_count);
+      (void) vm_deallocate (mach_task_self(), (vm_address_t)threads, 
+			    (thread_count * sizeof(mach_port_t)));
+    }
+
+  return mid;
+}
+
+static int
+parse_thread_id (arg, thread_count, slots)
+     char *arg;
+     int thread_count;
+     int slots;
+{
+  kern_return_t ret;
+  int mid;
+  int slot;
+  int index;
+  
+  if (arg == 0)
+    return 0;
+  
+  while (*arg && (*arg == ' ' || *arg == '\t'))
+    arg++;
+  
+  if (! *arg)
+    return 0;
+  
+  /* Currently parse MID and @SLOTNUMBER */
+  if (*arg != '@')
+    {
+      mid = atoi (arg);
+      if (mid <= 0)
+	error ("valid thread mid expected");
+      return mid;
+    }
+  
+  arg++;
+  slot = atoi (arg);
+
+  if (slot < 0)
+    error ("invalid slot number");
+
+  /* If you want slot numbers to remain slot numbers, set slots.
+   *
+   * Well, since 0 is reserved, return the ordinal number
+   * of the thread rather than the slot number. Awk, this
+   * counts as a kludge.
+   */
+  if (slots)
+    return -(slot+1);
+
+  if (thread_count && slot >= thread_count)
+    return -(slot+1);
+
+  mid = map_slot_to_mid (slot);
+  
+  return mid;
+}
+
+/* THREAD_ID 0 is special; it selects the first kernel
+ * thread from the list (i.e. SLOTNUMBER 0)
+ * This is used when starting the program with 'run' or when attaching.
+ *
+ * If FLAG is 0 the context is not changed, and the registers, frame, etc
+ * will continue to describe the old thread.
+ *
+ * If FLAG is nonzero, really select the thread.
+ * If FLAG is 2, the THREAD_ID is a slotnumber instead of a mid.
+ * 
+ */
+kern_return_t
+select_thread (task, thread_id, flag)
+     mach_port_t task;
+     int thread_id;
+     int flag;
+{
+  thread_array_t thread_list;
+  int thread_count;
+  kern_return_t ret;
+  int index;
+  thread_t new_thread = MACH_PORT_NULL;
+
+  if (thread_id < 0)
+    error ("Can't select cprocs without kernel thread");
+
+  ret = task_threads (task, &thread_list, &thread_count);
+  if (ret != KERN_SUCCESS)
+    {
+      warning ("Can not select a thread from a dead task");
+      m3_kill_inferior ();
+      return KERN_FAILURE;
+    }
+
+  if (thread_count == 0)
+    {
+      /* The task can not do anything anymore, but it still
+       * exists as a container for memory and ports.
+       */
+      registers_changed ();
+      warning ("Task %d has no threads",
+	       map_port_name_to_mid (task, MACH_TYPE_TASK));
+      current_thread = MACH_PORT_NULL;
+      (void) vm_deallocate(mach_task_self(),
+			   (vm_address_t) thread_list,
+			   (thread_count * sizeof(mach_port_t)));
+      return KERN_FAILURE;
+    }
+
+  if (! thread_id || flag == 2)
+    {
+      /* First thread or a slotnumber */
+      if (! thread_id)
+	new_thread = thread_list[0];
+      else
+	{
+	  if (thread_id < thread_count)
+	    new_thread = thread_list[ thread_id ];
+	  else
+	    {
+	      (void) vm_deallocate(mach_task_self(),
+				   (vm_address_t) thread_list,
+				   (thread_count * sizeof(mach_port_t)));
+	      error ("No such thread slot number : %d", thread_id);
+	    }
+	}
+    }
+  else
+    {
+      for (index = 0; index < thread_count; index++)
+	if (thread_id == map_port_name_to_mid (thread_list [index],
+					       MACH_TYPE_THREAD))
+	  {
+	    new_thread = thread_list [index];
+	    index = -1;
+	    break;
+	  }
+      
+      if (index != -1)
+	error ("No thread with mid %d", thread_id);
+    }
+  
+  /* Notify when the selected thread dies */
+  request_notify (new_thread, MACH_NOTIFY_DEAD_NAME, MACH_TYPE_THREAD);
+  
+  ret = vm_deallocate(mach_task_self(),
+		      (vm_address_t) thread_list,
+		      (thread_count * sizeof(mach_port_t)));
+  CHK ("vm_deallocate", ret);
+  
+  if (! flag)
+    current_thread = new_thread;
+  else
+    {
+#if 0
+      if (MACH_PORT_VALID (current_thread))
+	{
+	  /* Store the gdb's view of the thread we are deselecting
+	   *
+	   * @@ I think gdb updates registers immediately when they are
+	   * changed, so don't do this.
+	   */
+	  ret = thread_abort (current_thread);
+	  CHK ("Could not abort system calls when saving state of old thread",
+	       ret);
+	  target_prepare_to_store ();
+	  target_store_registers (-1);
+	}
+#endif
+
+      registers_changed ();
+
+      current_thread = new_thread;
+
+      ret = thread_abort (current_thread);
+      CHK ("Could not abort system calls when selecting a thread", ret);
+
+      stop_pc = read_pc();
+      flush_cached_frames ();
+
+      select_frame (get_current_frame (), 0);
+    }
+
+  return KERN_SUCCESS;
+}
+
+/*
+ * Switch to use thread named NEW_THREAD.
+ * Return it's MID
+ */
+int
+switch_to_thread (new_thread)
+     thread_t new_thread;
+{
+  thread_t saved_thread = current_thread;
+  int mid;
+
+  mid = map_port_name_to_mid (new_thread,
+			      MACH_TYPE_THREAD);
+  if (mid == -1)
+    warning ("Can't map thread name 0x%x to mid", new_thread);
+  else if (select_thread (inferior_task, mid, 1) != KERN_SUCCESS)
+    {
+      if (current_thread)
+	current_thread = saved_thread;
+      error ("Could not select thread %d", mid);
+    }
+	
+  return mid;
+}
+
+/* Do this in gdb after doing FORK but before STARTUP_INFERIOR.
+ * Note that the registers are not yet valid in the inferior task.
+ */
+static int
+m3_trace_him (pid)
+     int pid;
+{
+  kern_return_t ret;
+
+  push_target (&m3_ops);
+
+  inferior_task = task_by_pid (pid);
+
+  if (! MACH_PORT_VALID (inferior_task))
+    error ("Can not map Unix pid %d to Mach task", pid);
+
+  /* Clean up previous notifications and create new ones */
+  setup_notify_port (1);
+
+  /* When notification appears, the inferior task has died */
+  request_notify (inferior_task, MACH_NOTIFY_DEAD_NAME, MACH_TYPE_TASK);
+
+  emulator_present = have_emulator_p (inferior_task);
+
+  /* By default, select the first thread,
+   * If task has no threads, gives a warning
+   * Does not fetch registers, since they are not yet valid.
+   */
+  select_thread (inferior_task, 0, 0);
+
+  inferior_exception_port = MACH_PORT_NULL;
+
+  setup_exception_port ();
+
+  xx_debug ("Now the debugged task is created\n");
+
+  /* One trap to exec the shell, one to exec the program being debugged.  */
+  intercept_exec_calls (2);
+
+  return pid;
+}
+
+setup_exception_port ()
+{
+  kern_return_t ret;
+
+  ret = mach_port_allocate (mach_task_self(), 
+			    MACH_PORT_RIGHT_RECEIVE,
+			    &inferior_exception_port);
+  CHK("mach_port_allocate",ret);
+
+  /* add send right */
+  ret = mach_port_insert_right (mach_task_self (),
+				inferior_exception_port,
+				inferior_exception_port,
+				MACH_MSG_TYPE_MAKE_SEND);
+  CHK("mach_port_insert_right",ret);
+
+  ret = mach_port_move_member (mach_task_self(), 
+			       inferior_exception_port,
+			       inferior_wait_port_set);
+  CHK("mach_port_move_member",ret);
+
+  ret = task_get_special_port (inferior_task, 
+			       TASK_EXCEPTION_PORT,
+			       &inferior_old_exception_port);
+  CHK ("task_get_special_port(old exc)",ret);
+
+  ret = task_set_special_port (inferior_task,
+			       TASK_EXCEPTION_PORT, 
+			       inferior_exception_port);
+  CHK("task_set_special_port",ret);
+
+  ret = mach_port_deallocate (mach_task_self (),
+			      inferior_exception_port);
+  CHK("mack_port_deallocate",ret);
+
+#if 0
+  /* When notify appears, the inferior_task's exception
+   * port has been destroyed.
+   *
+   * Not used, since the dead_name_notification already
+   * appears when task dies.
+   *
+   */
+  request_notify (inferior_exception_port,
+		  MACH_NOTIFY_NO_SENDERS,
+		  MACH_TYPE_EXCEPTION_PORT);
+#endif
+}
+
+/* Nonzero if gdb is waiting for a message */
+int mach_really_waiting;
+
+/* Wait for the inferior to stop for some reason.
+   - Loop on notifications until inferior_task dies.
+   - Loop on exceptions until stopped_in_exception comes true.
+     (e.g. we receive a single step trace trap)
+   - a message arrives to gdb's message port
+
+   There is no other way to exit this loop.
+
+   Returns the inferior_pid for rest of gdb.
+   Side effects: Set *OURSTATUS.  */
+int
+mach_really_wait (pid, ourstatus)
+     int pid;
+     struct target_waitstatus *ourstatus;
+{
+  kern_return_t ret;
+  int w;
+
+  struct msg {
+    mach_msg_header_t    header;
+    mach_msg_type_t foo;
+    int             data[8000];
+  } in_msg, out_msg;
+
+  /* Either notify (death), exception or message can stop the inferior */
+  stopped_in_exception = FALSE;
+
+  while (1)
+    {
+      QUIT;
+
+      stop_exception = stop_code = stop_subcode = -1;
+      stop_thread = MACH_PORT_NULL;
+
+      mach_really_waiting = 1;
+      ret = mach_msg (&in_msg.header,		/* header */
+		      MACH_RCV_MSG,		/* options */
+		      0,			/* send size */
+		      sizeof (struct msg),	/* receive size */
+		      currently_waiting_for,	/* receive name */
+		      MACH_MSG_TIMEOUT_NONE,
+		      MACH_PORT_NULL);
+      mach_really_waiting = 0;
+      CHK("mach_msg (receive)", ret);
+
+      /* Check if we received a notify of the childs' death */
+      if (notify_server (&in_msg.header, &out_msg.header))
+	{
+	  /* If inferior_task is null then the inferior has
+	     gone away and we want to return to command level.
+	     Otherwise it was just an informative message and we
+	     need to look to see if there are any more. */
+	  if (inferior_task != MACH_PORT_NULL)
+	    continue;
+	  else
+	    {
+	      /* Collect Unix exit status for gdb */
+
+	      wait3(&w, WNOHANG, 0);
+
+	      /* This mess is here to check that the rest of
+	       * gdb knows that the inferior died. It also
+	       * tries to hack around the fact that Mach 3.0 (mk69)
+	       * unix server (ux28) does not always know what
+	       * has happened to it's children when mach-magic
+	       * is applied on them.
+	       */
+	      if ((!WIFEXITED(w) && WIFSTOPPED(w))         ||
+		  (WIFEXITED(w)  && WEXITSTATUS(w) > 0377))
+		{
+		  WSETEXIT(w, 0);
+		  warning ("Using exit value 0 for terminated task");
+		}
+	      else if (!WIFEXITED(w))
+		{
+		  int sig = WTERMSIG(w);
+
+		  /* Signals cause problems. Warn the user. */
+		  if (sig != SIGKILL) /* Bad luck if garbage matches this */
+		    warning ("The terminating signal stuff may be nonsense");
+		  else if (sig > NSIG)
+		    {
+		      WSETEXIT(w, 0);
+		      warning ("Using exit value 0 for terminated task");
+		    }
+		}
+	      store_waitstatus (ourstatus, w);
+	      return inferior_pid;
+	    }
+	}
+
+      /* Hmm. Check for exception, as it was not a notification.
+	 exc_server() does an upcall to catch_exception_raise()
+	 if this rpc is an exception. Further actions are decided
+	 there.
+       */
+      if (! exc_server (&in_msg.header, &out_msg.header))
+	{
+
+	  /* Not an exception, check for message.
+	   *
+	   * Messages don't come from the inferior, or if they
+	   * do they better be asynchronous or it will hang.
+	   */
+	  if (gdb_message_server (&in_msg.header))
+	    continue;
+
+	  error ("Unrecognized message received in mach_really_wait");
+	}
+
+      /* Send the reply of the exception rpc to the suspended task */
+      ret = mach_msg_send (&out_msg.header);
+      CHK ("mach_msg_send (exc reply)", ret);
+      
+      if (stopped_in_exception)
+	{
+	  /* Get unix state. May be changed in mach3_exception_actions() */
+	  wait3(&w, WNOHANG, 0);
+
+	  mach3_exception_actions (&w, FALSE, "Task");
+
+	  store_waitstatus (ourstatus, w);
+	  return inferior_pid;
+	}
+    }
+}
+
+/* Called by macro DO_QUIT() in utils.c(quit).
+ * This is called just before calling error() to return to command level
+ */
+void
+mach3_quit ()
+{
+  int mid;
+  kern_return_t ret;
+  
+  if (mach_really_waiting)
+    {
+      ret = task_suspend (inferior_task);
+      
+      if (ret != KERN_SUCCESS)
+	{
+	  warning ("Could not suspend task for interrupt: %s",
+		   mach_error_string (ret));
+	  mach_really_waiting = 0;
+	  return;
+	}
+    }
+
+  must_suspend_thread = 0;
+  mach_really_waiting = 0;
+
+  mid = map_port_name_to_mid (current_thread, MACH_TYPE_THREAD);
+  if (mid == -1)
+    {
+      warning ("Selecting first existing kernel thread");
+      mid = 0;
+    }
+
+  current_thread = MACH_PORT_NULL; /* Force setup */
+  select_thread (inferior_task, mid, 1);
+
+  return;
+}
+
+#if 0
+/* bogus bogus bogus.  It is NOT OK to quit out of target_wait.  */
+
+/* If ^C is typed when we are waiting for a message
+ * and your Unix server is able to notice that we 
+ * should quit now.
+ *
+ * Called by REQUEST_QUIT() from utils.c(request_quit)
+ */
+void
+mach3_request_quit ()
+{
+  if (mach_really_waiting)
+    immediate_quit = 1;
+}      
+#endif
+
+/*
+ * Gdb message server.
+ * Currently implemented is the STOP message, that causes
+ * gdb to return to the command level like ^C had been typed from terminal.
+ */
+int
+gdb_message_server (InP)
+     mach_msg_header_t *InP;
+{
+  kern_return_t ret;
+  int mid;
+
+  if (InP->msgh_local_port == our_message_port)
+    {
+      /* A message coming to our_message_port. Check validity */
+      switch (InP->msgh_id) {
+
+      case GDB_MESSAGE_ID_STOP:
+	ret = task_suspend (inferior_task);
+	if (ret != KERN_SUCCESS)
+	  warning ("Could not suspend task for stop message: %s",
+		   mach_error_string (ret));
+
+	/* QUIT in mach_really_wait() loop. */
+	request_quit (0);
+	break;
+
+      default:
+	warning ("Invalid message id %d received, ignored.",
+		 InP->msgh_id);
+	break;
+      }
+
+      return 1;
+    }
+
+  /* Message not handled by this server */
+  return 0;
+}
+
+/* NOTE: This is not an RPC call. It is a simpleroutine.
+ *
+ * This is not called from this gdb code.
+ *
+ * It may be called by another debugger to cause this
+ * debugger to enter command level:
+ *
+ *            (gdb) set stop_inferior_gdb ()
+ *            (gdb) continue
+ *
+ * External program "stop-gdb" implements this also.
+ */
+void
+stop_inferior_gdb ()
+{
+  kern_return_t ret;
+
+  /* Code generated by mig, with minor cleanups :-)
+   *
+   * simpleroutine stop_inferior_gdb (our_message_port : mach_port_t);
+   */
+
+  typedef struct {
+    mach_msg_header_t Head;
+  } Request;
+
+  Request Mess;
+
+  register Request *InP = &Mess;
+
+  InP->Head.msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_COPY_SEND, 0);
+
+  /* msgh_size passed as argument */
+  InP->Head.msgh_remote_port = our_message_port;
+  InP->Head.msgh_local_port  = MACH_PORT_NULL;
+  InP->Head.msgh_seqno       = 0;
+  InP->Head.msgh_id          = GDB_MESSAGE_ID_STOP;
+
+  ret = mach_msg (&InP->Head,
+		  MACH_SEND_MSG|MACH_MSG_OPTION_NONE,
+		  sizeof(Request),
+		  0,
+		  MACH_PORT_NULL,
+		  MACH_MSG_TIMEOUT_NONE,
+		  MACH_PORT_NULL);
+}
+
+#ifdef THREAD_ALLOWED_TO_BREAK
+/*
+ * Return 1 if the MID specifies the thread that caused the
+ * last exception.
+ *  Since catch_exception_raise() selects the thread causing
+ * the last exception to current_thread, we just check that
+ * it is selected and the last exception was a breakpoint.
+ */
+int
+mach_thread_for_breakpoint (mid)
+     int mid;
+{
+  int cmid = map_port_name_to_mid (current_thread, MACH_TYPE_THREAD);
+
+  if (mid < 0)
+    {
+      mid = map_slot_to_mid (-(mid+1), 0, 0);
+      if (mid < 0)
+	return 0;		/* Don't stop, no such slot */
+    }
+
+  if (! mid || cmid == -1)
+    return 1;	/* stop */
+
+  return cmid == mid && stop_exception == EXC_BREAKPOINT;
+}
+#endif /* THREAD_ALLOWED_TO_BREAK */
+
+#ifdef THREAD_PARSE_ID
+/*
+ * Map a thread id string (MID or a @SLOTNUMBER)
+ * to a thread-id.
+ *
+ *   0  matches all threads.
+ *   Otherwise the meaning is defined only in this file.
+ *   (mach_thread_for_breakpoint uses it)
+ *
+ * @@ This allows non-existent MIDs to be specified.
+ *    It now also allows non-existent slots to be
+ *    specified. (Slot numbers stored are negative,
+ *    and the magnitude is one greater than the actual
+ *    slot index. (Since 0 is reserved))
+ */
+int
+mach_thread_parse_id (arg)
+     char *arg;
+{
+  int mid;
+  if (arg == 0)
+    error ("thread id excpected");
+  mid = parse_thread_id (arg, 0, 1);
+
+  return mid;
+}
+#endif /* THREAD_PARSE_ID */
+
+#ifdef THREAD_OUTPUT_ID
+char *
+mach_thread_output_id (mid)
+     int mid;
+{
+  static char foobar [20];
+
+  if (mid > 0)
+    sprintf (foobar, "mid %d", mid);
+  else if (mid < 0)
+    sprintf (foobar, "@%d", -(mid+1));
+  else
+    sprintf (foobar, "*any thread*");
+
+  return foobar;
+}
+#endif /* THREAD_OUTPUT_ID */
+
+/* Called with hook PREPARE_TO_PROCEED() from infrun.c.
+ *
+ * If we have switched threads and stopped at breakpoint return 1 otherwise 0.
+ *
+ *  if SELECT_IT is nonzero, reselect the thread that was active when
+ *  we stopped at a breakpoint.
+ *
+ */
+
+mach3_prepare_to_proceed (select_it)
+     int select_it;
+{
+  if (stop_thread &&
+      stop_thread != current_thread &&
+      stop_exception == EXC_BREAKPOINT)
+    {
+      int mid;
+
+      if (! select_it)
+	return 1;
+
+      mid = switch_to_thread (stop_thread);
+
+      return 1;
+    }
+
+  return 0;
+}
+
+/* this stuff here is an upcall via libmach/excServer.c 
+   and mach_really_wait which does the actual upcall.
+
+   The code will pass the exception to the inferior if:
+
+     - The task that signaled is not the inferior task
+       (e.g. when debugging another debugger)
+
+     - The user has explicitely requested to pass on the exceptions.
+       (e.g to the default unix exception handler, which maps
+	exceptions to signals, or the user has her own exception handler)
+
+     - If the thread that signaled is being single-stepped and it
+       has set it's own exception port and the exception is not
+       EXC_BREAKPOINT. (Maybe this is not desirable?)
+ */
+
+kern_return_t
+catch_exception_raise (port, thread, task, exception, code, subcode)
+     mach_port_t port;
+     thread_t thread;
+     task_t task;
+     int exception, code, subcode;
+{
+  kern_return_t ret;
+  boolean_t signal_thread;
+  int mid = map_port_name_to_mid (thread, MACH_TYPE_THREAD);
+
+  if (! MACH_PORT_VALID (thread))
+    {
+      /* If the exception was sent and thread dies before we
+	 receive it, THREAD will be MACH_PORT_DEAD
+       */
+
+      current_thread = thread = MACH_PORT_NULL;
+      error ("Received exception from nonexistent thread");
+    }
+
+  /* Check if the task died in transit.
+   * @@ Isn't the thread also invalid in such case?
+   */
+  if (! MACH_PORT_VALID (task))
+    {
+      current_thread = thread = MACH_PORT_NULL;
+      error ("Received exception from nonexistent task");
+    }
+
+  if (exception < 0 || exception > MAX_EXCEPTION)
+    fatal ("catch_exception_raise: unknown exception code %d thread %d",
+	   exception,
+	   mid);
+
+  if (! MACH_PORT_VALID (inferior_task))
+    error ("got an exception, but inferior_task is null or dead");
+  
+  stop_exception = exception;
+  stop_code      = code;
+  stop_subcode   = subcode;  
+  stop_thread    = thread;
+  
+  signal_thread = exception != EXC_BREAKPOINT       &&
+    		  port == singlestepped_thread_port &&
+		  MACH_PORT_VALID (thread_saved_exception_port);
+
+  /* If it was not our inferior or if we want to forward
+   * the exception to the inferior's handler, do it here
+   *
+   * Note: If you have forwarded EXC_BREAKPOINT I trust you know why.
+   */
+  if (task != inferior_task ||
+      signal_thread         ||
+      exception_map [exception].forward)
+    {
+      mach_port_t eport = inferior_old_exception_port;
+
+      if (signal_thread)
+	{
+	  /*
+	    GDB now forwards the exeption to thread's original handler,
+	    since the user propably knows what he is doing.
+	    Give a message, though.
+	   */
+
+	  mach3_exception_actions ((WAITTYPE *)NULL, TRUE, "Thread");
+	  eport = thread_saved_exception_port;
+	}
+
+      /* Send the exception to the original handler */
+      ret = exception_raise (eport,
+			     thread, 
+			     task,
+			     exception,
+			     code,
+			     subcode);
+
+      (void) mach_port_deallocate (mach_task_self (), task);
+      (void) mach_port_deallocate (mach_task_self (), thread);
+
+      /* If we come here, we don't want to trace any more, since we
+       * will never stop for tracing anyway.
+       */
+      discard_single_step (thread);
+
+      /* Do not stop the inferior */
+      return ret;
+    }
+  
+  /* Now gdb handles the exception */
+  stopped_in_exception = TRUE;
+
+  ret = task_suspend (task);
+  CHK ("Error suspending inferior after exception", ret);
+
+  must_suspend_thread = 0;
+
+  if (current_thread != thread)
+    {
+      if (MACH_PORT_VALID (singlestepped_thread_port))
+	/* Cleanup discards single stepping */
+	error ("Exception from thread %d while singlestepping thread %d",
+	       mid,
+	       map_port_name_to_mid (current_thread, MACH_TYPE_THREAD));
+      
+      /* Then select the thread that caused the exception */
+      if (select_thread (inferior_task, mid, 0) != KERN_SUCCESS)
+	error ("Could not select thread %d causing exception", mid);
+      else
+	warning ("Gdb selected thread %d", mid);
+    }
+
+  /* If we receive an exception that is not breakpoint
+   * exception, we interrupt the single step and return to
+   * debugger. Trace condition is cleared.
+   */
+  if (MACH_PORT_VALID (singlestepped_thread_port))
+    {
+      if (stop_exception != EXC_BREAKPOINT)
+	warning ("Single step interrupted by exception");
+      else if (port == singlestepped_thread_port)
+	{
+	  /* Single step exception occurred, remove trace bit
+	   * and return to gdb.
+	   */
+	  if (! MACH_PORT_VALID (current_thread))
+	    error ("Single stepped thread is not valid");
+	
+	  /* Resume threads, but leave the task suspended */
+	  resume_all_threads (0);
+	}
+      else
+	warning ("Breakpoint while single stepping?");
+
+      discard_single_step (current_thread);
+    }
+  
+  (void) mach_port_deallocate (mach_task_self (), task);
+  (void) mach_port_deallocate (mach_task_self (), thread);
+
+  return KERN_SUCCESS;
+}
+
+int
+port_valid (port, mask)
+  mach_port_t port;
+  int         mask;
+{
+  kern_return_t ret;
+  mach_port_type_t type;
+
+  ret = mach_port_type (mach_task_self (),
+			port,
+			&type);
+  if (ret != KERN_SUCCESS || (type & mask) != mask)
+    return 0;
+  return 1;
+}
+
+/* @@ No vm read cache implemented yet */
+boolean_t vm_read_cache_valid = FALSE;
+
+/*
+ * Read inferior task's LEN bytes from ADDR and copy it to MYADDR
+ * in gdb's address space.
+ *
+ * Return 0 on failure; number of bytes read otherwise.
+ */
+int
+mach3_read_inferior (addr, myaddr, length)
+     CORE_ADDR addr;
+     char *myaddr;
+     int length;
+{
+  kern_return_t ret;
+  vm_address_t low_address       = (vm_address_t) trunc_page (addr);
+  vm_size_t    aligned_length = 
+    			(vm_size_t) round_page (addr+length) - low_address;
+  pointer_t    copied_memory;
+  int	       copy_count;
+
+  /* Get memory from inferior with page aligned addresses */
+  ret = vm_read (inferior_task,
+		 low_address,
+		 aligned_length,
+		 &copied_memory,
+		 &copy_count);
+  if (ret != KERN_SUCCESS)
+    {
+      /* the problem is that the inferior might be killed for whatever reason
+       * before we go to mach_really_wait. This is one place that ought to
+       * catch many of those errors.
+       * @@ A better fix would be to make all external events to GDB
+       * to arrive via a SINGLE port set. (Including user input!)
+       */
+
+      if (! port_valid (inferior_task, MACH_PORT_TYPE_SEND))
+	{
+	  m3_kill_inferior ();
+	  error ("Inferior killed (task port invalid)");
+	}
+      else
+	{
+#ifdef OSF
+	  extern int errno;
+	  /* valprint.c gives nicer format if this does not
+	     screw it. Eamonn seems to like this, so I enable
+	     it if OSF is defined...
+	   */
+	  warning ("[read inferior %x failed: %s]",
+		   addr, mach_error_string (ret));
+	  errno = 0;
+#endif
+	  return 0;
+	}
+    }
+
+  memcpy (myaddr, (char *)addr - low_address + copied_memory, length);
+
+  ret = vm_deallocate (mach_task_self (),
+		       copied_memory,
+		       copy_count);
+  CHK("mach3_read_inferior vm_deallocate failed", ret);
+
+  return length;
+}
+
+#ifdef __STDC__
+#define CHK_GOTO_OUT(str,ret) \
+  do if (ret != KERN_SUCCESS) { errstr = #str; goto out; } while(0)
+#else
+#define CHK_GOTO_OUT(str,ret) \
+  do if (ret != KERN_SUCCESS) { errstr = str; goto out; } while(0)
+#endif
+
+struct vm_region_list {
+  struct vm_region_list *next;
+  vm_prot_t	protection;
+  vm_address_t  start;
+  vm_size_t	length;
+};
+
+struct obstack  region_obstack;
+
+/*
+ * Write inferior task's LEN bytes from ADDR and copy it to MYADDR
+ * in gdb's address space.
+ */
+int
+mach3_write_inferior (addr, myaddr, length)
+     CORE_ADDR addr;
+     char *myaddr;
+     int length;
+{
+  kern_return_t ret;
+  vm_address_t low_address       = (vm_address_t) trunc_page (addr);
+  vm_size_t    aligned_length = 
+    			(vm_size_t) round_page (addr+length) - low_address;
+  pointer_t    copied_memory;
+  int	       copy_count;
+  int	       deallocate = 0;
+
+  char         *errstr = "Bug in mach3_write_inferior";
+
+  struct vm_region_list *region_element;
+  struct vm_region_list *region_head = (struct vm_region_list *)NULL;
+
+  /* Get memory from inferior with page aligned addresses */
+  ret = vm_read (inferior_task,
+		 low_address,
+		 aligned_length,
+		 &copied_memory,
+		 &copy_count);
+  CHK_GOTO_OUT ("mach3_write_inferior vm_read failed", ret);
+
+  deallocate++;
+
+  memcpy ((char *)addr - low_address + copied_memory, myaddr, length);
+
+  obstack_init (&region_obstack);
+
+  /* Do writes atomically.
+   * First check for holes and unwritable memory.
+   */
+  {
+    vm_size_t    remaining_length  = aligned_length;
+    vm_address_t region_address    = low_address;
+
+    struct vm_region_list *scan;
+
+    while(region_address < low_address + aligned_length)
+      {
+	vm_prot_t protection;
+	vm_prot_t max_protection;
+	vm_inherit_t inheritance;
+	boolean_t shared;
+	mach_port_t object_name;
+	vm_offset_t offset;
+	vm_size_t   region_length = remaining_length;
+	vm_address_t old_address  = region_address;
+    
+	ret = vm_region (inferior_task,
+			 &region_address,
+			 &region_length,
+			 &protection,
+			 &max_protection,
+			 &inheritance,
+			 &shared,
+			 &object_name,
+			 &offset);
+	CHK_GOTO_OUT ("vm_region failed", ret);
+
+	/* Check for holes in memory */
+	if (old_address != region_address)
+	  {
+	    warning ("No memory at 0x%x. Nothing written",
+		     old_address);
+	    ret = KERN_SUCCESS;
+	    length = 0;
+	    goto out;
+	  }
+
+	if (!(max_protection & VM_PROT_WRITE))
+	  {
+	    warning ("Memory at address 0x%x is unwritable. Nothing written",
+		     old_address);
+	    ret = KERN_SUCCESS;
+	    length = 0;
+	    goto out;
+	  }
+
+	/* Chain the regions for later use */
+	region_element = 
+	  (struct vm_region_list *)
+	    obstack_alloc (&region_obstack, sizeof (struct vm_region_list));
+    
+	region_element->protection = protection;
+	region_element->start      = region_address;
+	region_element->length     = region_length;
+
+	/* Chain the regions along with protections */
+	region_element->next = region_head;
+	region_head          = region_element;
+	
+	region_address += region_length;
+	remaining_length = remaining_length - region_length;
+      }
+
+    /* If things fail after this, we give up.
+     * Somebody is messing up inferior_task's mappings.
+     */
+    
+    /* Enable writes to the chained vm regions */
+    for (scan = region_head; scan; scan = scan->next)
+      {
+	boolean_t protection_changed = FALSE;
+	
+	if (!(scan->protection & VM_PROT_WRITE))
+	  {
+	    ret = vm_protect (inferior_task,
+			      scan->start,
+			      scan->length,
+			      FALSE,
+			      scan->protection | VM_PROT_WRITE);
+	    CHK_GOTO_OUT ("vm_protect: enable write failed", ret);
+	  }
+      }
+
+    ret = vm_write (inferior_task,
+		    low_address,
+		    copied_memory,
+		    aligned_length);
+    CHK_GOTO_OUT ("vm_write failed", ret);
+	
+    /* Set up the original region protections, if they were changed */
+    for (scan = region_head; scan; scan = scan->next)
+      {
+	boolean_t protection_changed = FALSE;
+	
+	if (!(scan->protection & VM_PROT_WRITE))
+	  {
+	    ret = vm_protect (inferior_task,
+			      scan->start,
+			      scan->length,
+			      FALSE,
+			      scan->protection);
+	    CHK_GOTO_OUT ("vm_protect: enable write failed", ret);
+	  }
+      }
+  }
+
+ out:
+  if (deallocate)
+    {
+      obstack_free (&region_obstack, 0);
+      
+      (void) vm_deallocate (mach_task_self (),
+			    copied_memory,
+			    copy_count);
+    }
+
+  if (ret != KERN_SUCCESS)
+    {
+      warning ("%s %s", errstr, mach_error_string (ret));
+      return 0;
+    }
+
+  return length;
+}
+
+/* Return 0 on failure, number of bytes handled otherwise.  */
+static int
+m3_xfer_memory (memaddr, myaddr, len, write, target)
+     CORE_ADDR memaddr;
+     char *myaddr;
+     int len;
+     int write;
+     struct target_ops *target;	/* IGNORED */
+{
+  int result;
+
+  if (write)
+    result = mach3_write_inferior (memaddr, myaddr, len);
+  else
+    result = mach3_read_inferior  (memaddr, myaddr, len);
+
+  return result;
+}
+
+
+static char *
+translate_state(state)
+int	state;
+{
+  switch (state) {
+  case TH_STATE_RUNNING:	return("R");
+  case TH_STATE_STOPPED:	return("S");
+  case TH_STATE_WAITING:	return("W");
+  case TH_STATE_UNINTERRUPTIBLE: return("U");
+  case TH_STATE_HALTED:		return("H");
+  default:			return("?");
+  }
+}
+
+static char *
+translate_cstate (state)
+     int state;
+{
+  switch (state)
+    {
+    case CPROC_RUNNING:	return "R";
+    case CPROC_SWITCHING: return "S";
+    case CPROC_BLOCKED: return "B";
+    case CPROC_CONDWAIT: return "C";
+    case CPROC_CONDWAIT|CPROC_SWITCHING: return "CS";
+    default: return "?";
+    }
+}
+
+/* type == MACH_MSG_TYPE_COPY_SEND || type == MACH_MSG_TYPE_MAKE_SEND */
+
+mach_port_t           /* no mach_port_name_t found in include files. */
+map_inferior_port_name (inferior_name, type)
+     mach_port_t inferior_name;
+     mach_msg_type_name_t type;
+{
+  kern_return_t        ret;
+  mach_msg_type_name_t acquired;
+  mach_port_t          iport;
+  
+  ret = mach_port_extract_right (inferior_task,
+				 inferior_name,
+				 type,
+				 &iport,
+				 &acquired);
+  CHK("mach_port_extract_right (map_inferior_port_name)", ret);
+
+  if (acquired != MACH_MSG_TYPE_PORT_SEND)
+    error("Incorrect right extracted, (map_inferior_port_name)");
+
+  ret = mach_port_deallocate (mach_task_self (),
+			      iport);
+  CHK ("Deallocating mapped port (map_inferior_port_name)", ret);
+
+  return iport;
+}
+
+/*
+ * Naming convention:
+ *  Always return user defined name if found.
+ *  _K == A kernel thread with no matching CPROC
+ *  _C == A cproc with no current cthread
+ *  _t == A cthread with no user defined name
+ *
+ * The digits that follow the _names are the SLOT number of the
+ * kernel thread if there is such a thing, otherwise just a negation
+ * of the sequential number of such cprocs.
+ */
+
+static char buf[7];
+
+static char *
+get_thread_name (one_cproc, id)
+     gdb_thread_t one_cproc;
+     int id;
+{
+  if (one_cproc)
+    if (one_cproc->cthread == NULL)
+      {
+	/* cproc not mapped to any cthread */
+	sprintf(buf, "_C%d", id);
+      }
+    else if (! one_cproc->cthread->name)
+      {
+	/* cproc and cthread, but no name */
+	sprintf(buf, "_t%d", id);
+      }
+    else
+      return (char *)(one_cproc->cthread->name);
+  else
+    {
+      if (id < 0)
+	warning ("Inconsistency in thread name id %d", id);
+
+      /* Kernel thread without cproc */
+      sprintf(buf, "_K%d", id);
+    }
+
+  return buf;
+}
+
+int
+fetch_thread_info (task, mthreads_out)
+     mach_port_t	task;
+     gdb_thread_t	*mthreads_out;	/* out */
+{
+  kern_return_t  ret;
+  thread_array_t th_table;
+  int		 th_count;
+  gdb_thread_t mthreads = NULL;
+  int 		 index;
+
+  ret = task_threads (task, &th_table, &th_count);
+  if (ret != KERN_SUCCESS)
+    {
+      warning ("Error getting inferior's thread list:%s",
+	       mach_error_string(ret));
+      m3_kill_inferior ();
+      return -1;
+    }
+  
+  mthreads = (gdb_thread_t)
+    		obstack_alloc
+		  (cproc_obstack,
+		   th_count * sizeof (struct gdb_thread));
+
+  for (index = 0; index < th_count; index++)
+    {
+      thread_t saved_thread = MACH_PORT_NULL;
+      int mid;
+
+      if (must_suspend_thread)
+	setup_thread (th_table[ index ], 1);
+
+      if (th_table[index] != current_thread)
+	{
+	  saved_thread = current_thread;
+	  
+	  mid = switch_to_thread (th_table[ index ]);
+	}
+
+      mthreads[index].name  = th_table[index];
+      mthreads[index].cproc = NULL;	/* map_cprocs_to_kernel_threads() */
+      mthreads[index].in_emulator = FALSE;
+      mthreads[index].slotid = index;
+      
+      mthreads[index].sp = read_register (SP_REGNUM);
+      mthreads[index].fp = read_register (FP_REGNUM);
+      mthreads[index].pc = read_pc ();
+
+      if (MACH_PORT_VALID (saved_thread))
+	mid = switch_to_thread (saved_thread);
+
+      if (must_suspend_thread)
+	setup_thread (th_table[ index ], 0);
+    }
+  
+  consume_send_rights (th_table, th_count);
+  ret = vm_deallocate (mach_task_self(), (vm_address_t)th_table, 
+		       (th_count * sizeof(mach_port_t)));
+  if (ret != KERN_SUCCESS)
+    {
+      warning ("Error trying to deallocate thread list : %s",
+	       mach_error_string (ret));
+    }
+
+  *mthreads_out = mthreads;
+
+  return th_count;
+}
+
+
+/*
+ * Current emulator always saves the USP on top of
+ * emulator stack below struct emul_stack_top stuff.
+ */
+CORE_ADDR
+fetch_usp_from_emulator_stack (sp)
+     CORE_ADDR sp;
+{
+  CORE_ADDR stack_pointer;
+
+  sp = (sp & ~(EMULATOR_STACK_SIZE-1)) +
+    	EMULATOR_STACK_SIZE - sizeof (struct emul_stack_top);
+  
+  if (mach3_read_inferior (sp,
+			   &stack_pointer,
+			   sizeof (CORE_ADDR)) != sizeof (CORE_ADDR))
+    {
+      warning ("Can't read user sp from emulator stack address 0x%x", sp);
+      return 0;
+    }
+
+  return stack_pointer;
+}
+
+#ifdef MK67
+
+/* get_emulation_vector() interface was changed after mk67 */
+#define EMUL_VECTOR_COUNT 400	/* Value does not matter too much */
+
+#endif /* MK67 */
+
+/* Check if the emulator exists at task's address space.
+ */
+boolean_t
+have_emulator_p (task)
+     task_t task;
+{
+  kern_return_t	ret;
+#ifndef EMUL_VECTOR_COUNT
+  vm_offset_t	*emulation_vector;
+  int		n;
+#else
+  vm_offset_t	emulation_vector[ EMUL_VECTOR_COUNT ];
+  int		n = EMUL_VECTOR_COUNT;
+#endif
+  int		i;
+  int		vector_start;
+  
+  ret = task_get_emulation_vector (task,
+				   &vector_start,
+#ifndef EMUL_VECTOR_COUNT
+				   &emulation_vector,
+#else
+				   emulation_vector,
+#endif
+				   &n);
+  CHK("task_get_emulation_vector", ret);
+  xx_debug ("%d vectors from %d at 0x%08x\n",
+	    n, vector_start, emulation_vector);
+  
+  for(i = 0; i < n; i++)
+    {
+      vm_offset_t entry = emulation_vector [i];
+
+      if (EMULATOR_BASE <= entry && entry <= EMULATOR_END)
+	return TRUE;
+      else if (entry)
+	{
+	  static boolean_t informed = FALSE;
+	  if (!informed)
+	    {
+	      warning("Emulation vector address 0x08%x outside emulator space",
+		      entry);
+	      informed = TRUE;
+	    }
+	}
+    }
+  return FALSE;
+}
+
+/* Map cprocs to kernel threads and vice versa.  */
+
+void
+map_cprocs_to_kernel_threads (cprocs, mthreads, thread_count)
+     gdb_thread_t cprocs;
+     gdb_thread_t mthreads;
+     int thread_count;
+{
+  int index;
+  gdb_thread_t scan;
+  boolean_t all_mapped = TRUE;
+  LONGEST stack_base;
+  LONGEST stack_size;
+
+  for (scan = cprocs; scan; scan = scan->next)
+    {
+      /* Default to: no kernel thread for this cproc */
+      scan->reverse_map = -1;
+
+      /* Check if the cproc is found by its stack */
+      for (index = 0; index < thread_count; index++)
+	{
+	  stack_base =
+	    extract_signed_integer (scan->raw_cproc + CPROC_BASE_OFFSET,
+				    CPROC_BASE_SIZE);
+	  stack_size = 
+	    extract_signed_integer (scan->raw_cproc + CPROC_SIZE_OFFSET,
+				    CPROC_SIZE_SIZE);
+	  if ((mthreads + index)->sp > stack_base &&
+	      (mthreads + index)->sp <= stack_base + stack_size)
+	    {
+	      (mthreads + index)->cproc = scan;
+	      scan->reverse_map = index;
+	      break;
+	    }
+	}
+      all_mapped &= (scan->reverse_map != -1);
+    }
+
+  /* Check for threads that are currently in the emulator.
+   * If so, they have a different stack, and the still unmapped
+   * cprocs may well get mapped to these threads.
+   * 
+   * If:
+   *  - cproc stack does not match any kernel thread stack pointer
+   *  - there is at least one extra kernel thread
+   *    that has no cproc mapped above.
+   *  - some kernel thread stack pointer points to emulator space
+   *  then we find the user stack pointer saved in the emulator
+   *  stack, and try to map that to the cprocs.
+   *
+   * Also set in_emulator for kernel threads.
+   */ 
+
+  if (emulator_present)
+    {
+      for (index = 0; index < thread_count; index++)
+	{
+	  CORE_ADDR emul_sp;
+	  CORE_ADDR usp;
+
+	  gdb_thread_t mthread = (mthreads+index);
+	  emul_sp = mthread->sp;
+
+	  if (mthread->cproc == NULL &&
+	      EMULATOR_BASE <= emul_sp && emul_sp <= EMULATOR_END)
+	    {
+	      mthread->in_emulator = emulator_present;
+	      
+	      if (!all_mapped && cprocs)
+		{
+		  usp = fetch_usp_from_emulator_stack (emul_sp);
+		  
+		  /* @@ Could be more accurate */
+		  if (! usp)
+		    error ("Zero stack pointer read from emulator?");
+		  
+		  /* Try to match this stack pointer to the cprocs that
+		   * don't yet have a kernel thread.
+		   */
+		  for (scan = cprocs; scan; scan = scan->next)
+		    {
+		      
+		      /* Check is this unmapped CPROC stack contains
+		       * the user stack pointer saved in the
+		       * emulator.
+		       */
+		      if (scan->reverse_map == -1)
+			{
+			  stack_base =
+			    extract_signed_integer
+			      (scan->raw_cproc + CPROC_BASE_OFFSET,
+			       CPROC_BASE_SIZE);
+			  stack_size = 
+			    extract_signed_integer
+			      (scan->raw_cproc + CPROC_SIZE_OFFSET,
+			       CPROC_SIZE_SIZE);
+			  if (usp > stack_base &&
+			      usp <= stack_base + stack_size)
+			    {
+			      mthread->cproc = scan;
+			      scan->reverse_map = index;
+			      break;
+			    }
+			}
+		    }
+		}
+	    }
+	}
+    }
+}
+
+/*
+ * Format of the thread_list command
+ *
+ * 	             slot mid sel   name  emul ks susp  cstate wired   address
+ */
+#define TL_FORMAT "%-2.2s %5d%c %-10.10s %1.1s%s%-5.5s %-2.2s %-5.5s "
+
+#define TL_HEADER "\n@    MID  Name        KState CState   Where\n"
+
+void
+print_tl_address (stream, pc)
+     GDB_FILE *stream;
+     CORE_ADDR pc;
+{
+  if (! lookup_minimal_symbol_by_pc (pc))
+    fprintf_filtered (stream, local_hex_format(), pc);
+  else
+    {
+      extern int addressprint;
+      extern int asm_demangle;
+
+      int store    = addressprint;
+      addressprint = 0;
+      print_address_symbolic (pc, stream, asm_demangle, "");
+      addressprint = store;
+    }
+}
+
+/* For thread names, but also for gdb_message_port external name */
+#define MAX_NAME_LEN 50
+
+/* Returns the address of variable NAME or 0 if not found */
+CORE_ADDR
+lookup_address_of_variable (name)
+     char *name;
+{
+  struct symbol *sym;
+  CORE_ADDR symaddr = 0;
+  struct minimal_symbol *msymbol;
+
+  sym = lookup_symbol (name,
+		       (struct block *)NULL,
+		       VAR_NAMESPACE,
+		       (int *)NULL,
+		       (struct symtab **)NULL);
+
+  if (sym)
+    symaddr = SYMBOL_VALUE (sym);
+
+  if (! symaddr)
+    {
+      msymbol = lookup_minimal_symbol (name, NULL, NULL);
+
+      if (msymbol && msymbol->type == mst_data)
+	symaddr = SYMBOL_VALUE_ADDRESS (msymbol);
+    }
+
+  return symaddr;
+}
+
+static gdb_thread_t
+get_cprocs()
+{
+  gdb_thread_t cproc_head;
+  gdb_thread_t cproc_copy;
+  CORE_ADDR their_cprocs;
+  char *buf[TARGET_PTR_BIT / HOST_CHAR_BIT];
+  char *name;
+  cthread_t cthread;
+  CORE_ADDR symaddr;
+  
+  symaddr = lookup_address_of_variable ("cproc_list");
+
+  if (! symaddr)
+    {
+      /* cproc_list is not in a file compiled with debugging
+	 symbols, but don't give up yet */
+
+      symaddr = lookup_address_of_variable ("cprocs");
+
+      if (symaddr)
+	{
+	  static int informed = 0;
+	  if (!informed)
+	    {
+	      informed++;
+	      warning ("Your program is loaded with an old threads library.");
+	      warning ("GDB does not know the old form of threads");
+	      warning ("so things may not work.");
+	    }
+	}
+    }
+
+  /* Stripped or no -lthreads loaded or "cproc_list" is in wrong segment. */
+  if (! symaddr)
+    return NULL;
+
+  /* Get the address of the first cproc in the task */
+  if (!mach3_read_inferior (symaddr,
+			    buf,
+			    TARGET_PTR_BIT / HOST_CHAR_BIT))
+    error ("Can't read cproc master list at address (0x%x).", symaddr);
+  their_cprocs = extract_address (buf, TARGET_PTR_BIT / HOST_CHAR_BIT);
+
+  /* Scan the CPROCs in the task.
+     CPROCs are chained with LIST field, not NEXT field, which
+     chains mutexes, condition variables and queues */
+
+  cproc_head = NULL;
+
+  while (their_cprocs != (CORE_ADDR)0)
+    {
+      CORE_ADDR cproc_copy_incarnation;
+      cproc_copy = (gdb_thread_t) obstack_alloc (cproc_obstack,
+						 sizeof (struct gdb_thread));
+
+      if (!mach3_read_inferior (their_cprocs,
+				&cproc_copy->raw_cproc[0],
+				CPROC_SIZE))
+	error("Can't read next cproc at 0x%x.", their_cprocs);
+
+      their_cprocs =
+	extract_address (cproc_copy->raw_cproc + CPROC_LIST_OFFSET,
+			 CPROC_LIST_SIZE);
+      cproc_copy_incarnation =
+	extract_address (cproc_copy->raw_cproc + CPROC_INCARNATION_OFFSET,
+			 CPROC_INCARNATION_SIZE);
+
+      if (cproc_copy_incarnation == (CORE_ADDR)0)
+	cproc_copy->cthread = NULL;
+      else
+	{
+	  /* This CPROC has an attached CTHREAD. Get its name */
+	  cthread = (cthread_t)obstack_alloc (cproc_obstack,
+					      sizeof(struct cthread));
+
+	  if (!mach3_read_inferior (cproc_copy_incarnation,
+				    cthread,
+				    sizeof(struct cthread)))
+	    error("Can't read next thread at 0x%x.",
+		  cproc_copy_incarnation);
+
+	  cproc_copy->cthread = cthread;
+
+	  if (cthread->name)
+	    {
+	      name = (char *) obstack_alloc (cproc_obstack, MAX_NAME_LEN);
+
+	      if (!mach3_read_inferior(cthread->name, name, MAX_NAME_LEN))
+		error("Can't read next thread's name at 0x%x.", cthread->name);
+
+	      cthread->name = name;
+	    }
+	}
+
+      /* insert in front */
+      cproc_copy->next = cproc_head;
+      cproc_head = cproc_copy;
+    }
+  return cproc_head;
+}
+
+#ifndef FETCH_CPROC_STATE
+/*
+ * Check if your machine does not grok the way this routine
+ * fetches the FP,PC and SP of a cproc that is not
+ * currently attached to any kernel thread (e.g. its cproc.context
+ * field points to the place in stack where the context
+ * is saved).
+ *
+ * If it doesn't, define your own routine.
+ */
+#define FETCH_CPROC_STATE(mth) mach3_cproc_state (mth)
+
+int
+mach3_cproc_state (mthread)
+     gdb_thread_t mthread;
+{
+  int context;
+
+  if (! mthread || !mthread->cproc)
+    return -1;
+
+  context = extract_signed_integer
+    (mthread->cproc->raw_cproc + CPROC_CONTEXT_OFFSET,
+     CPROC_CONTEXT_SIZE);
+  if (context == 0)
+    return -1;
+
+  mthread->sp = context + MACHINE_CPROC_SP_OFFSET;
+
+  if (mach3_read_inferior (context + MACHINE_CPROC_PC_OFFSET,
+			   &mthread->pc,
+			   sizeof (CORE_ADDR)) != sizeof (CORE_ADDR))
+    {
+      warning ("Can't read cproc pc from inferior");
+      return -1;
+    }
+
+  if (mach3_read_inferior (context + MACHINE_CPROC_FP_OFFSET,
+			   &mthread->fp,
+			   sizeof (CORE_ADDR)) != sizeof (CORE_ADDR))
+    {
+      warning ("Can't read cproc fp from inferior");
+      return -1;
+    }
+
+  return 0;
+}
+#endif /* FETCH_CPROC_STATE */
+
+
+void
+thread_list_command()
+{
+  thread_basic_info_data_t ths;
+  int     thread_count;
+  gdb_thread_t cprocs;
+  gdb_thread_t scan;
+  int     index;
+  char   *name;
+  char    selected;
+  char   *wired;
+  int     infoCnt;
+  kern_return_t ret;
+  mach_port_t   mid_or_port;
+  gdb_thread_t  their_threads;
+  gdb_thread_t  kthread;
+
+  int neworder = 1;
+
+  char *fmt = "There are %d kernel threads in task %d.\n";
+  
+  int tmid = map_port_name_to_mid (inferior_task, MACH_TYPE_TASK);
+  
+  MACH_ERROR_NO_INFERIOR;
+  
+  thread_count = fetch_thread_info (inferior_task,
+				    &their_threads);
+  if (thread_count == -1)
+    return;
+  
+  if (thread_count == 1)
+    fmt = "There is %d kernel thread in task %d.\n";
+  
+  printf_filtered (fmt, thread_count, tmid);
+  
+  puts_filtered (TL_HEADER);
+  
+  cprocs = get_cprocs();
+  
+  map_cprocs_to_kernel_threads (cprocs, their_threads, thread_count);
+  
+  for (scan = cprocs; scan; scan = scan->next)
+    {
+      int mid;
+      char buf[10];
+      char slot[3];
+      int cproc_state =
+	extract_signed_integer
+	  (scan->raw_cproc + CPROC_STATE_OFFSET, CPROC_STATE_SIZE);
+      
+      selected = ' ';
+      
+      /* a wired cproc? */
+      wired = (extract_address (scan->raw_cproc + CPROC_WIRED_OFFSET,
+				CPROC_WIRED_SIZE)
+	       ? "wired" : "");
+
+      if (scan->reverse_map != -1)
+	kthread  = (their_threads + scan->reverse_map);
+      else
+	kthread  = NULL;
+
+      if (kthread)
+	{
+	  /* These cprocs have a kernel thread */
+	  
+	  mid = map_port_name_to_mid (kthread->name, MACH_TYPE_THREAD);
+	  
+	  infoCnt = THREAD_BASIC_INFO_COUNT;
+	  
+	  ret = thread_info (kthread->name,
+			     THREAD_BASIC_INFO,
+			     (thread_info_t)&ths,
+			     &infoCnt);
+	  
+	  if (ret != KERN_SUCCESS)
+	    {
+	      warning ("Unable to get basic info on thread %d : %s",
+		       mid,
+		       mach_error_string (ret));
+	      continue;
+	    }
+
+	  /* Who is the first to have more than 100 threads */
+	  sprintf (slot, "%d", kthread->slotid%100);
+
+	  if (kthread->name == current_thread)
+	    selected = '*';
+	  
+	  if (ths.suspend_count)
+	    sprintf (buf, "%d", ths.suspend_count);
+	  else
+	    buf[0] = '\000';
+
+#if 0
+	  if (ths.flags & TH_FLAGS_SWAPPED)
+	    strcat (buf, "S");
+#endif
+
+	  if (ths.flags & TH_FLAGS_IDLE)
+	    strcat (buf, "I");
+
+	  printf_filtered (TL_FORMAT,
+			   slot,
+			   mid,
+			   selected,
+			   get_thread_name (scan, kthread->slotid),
+			   kthread->in_emulator ? "E" : "",
+			   translate_state (ths.run_state),
+			   buf,
+			   translate_cstate (cproc_state),
+			   wired);
+	  print_tl_address (gdb_stdout, kthread->pc);
+	}
+      else
+	{
+	  /* These cprocs don't have a kernel thread.
+	   * find out the calling frame with 
+	   * FETCH_CPROC_STATE.
+	   */
+
+	  struct gdb_thread state;
+
+#if 0
+	  /* jtv -> emcmanus: why do you want this here? */
+	  if (scan->incarnation == NULL)
+	    continue; /* EMcM */
+#endif
+
+	  printf_filtered (TL_FORMAT,
+			   "-",
+			   -neworder,	/* Pseudo MID */
+			   selected,
+			   get_thread_name (scan, -neworder),
+			   "",
+			   "-",	/* kernel state */
+			   "",
+			   translate_cstate (cproc_state),
+			   "");
+	  state.cproc = scan;
+
+	  if (FETCH_CPROC_STATE (&state) == -1)
+	    puts_filtered ("???");
+	  else
+	    print_tl_address (gdb_stdout, state.pc);
+
+	  neworder++;
+	}
+      puts_filtered ("\n");
+    }
+  
+  /* Scan for kernel threads without cprocs */
+  for (index = 0; index < thread_count; index++)
+    {
+      if (! their_threads[index].cproc)
+	{
+	  int mid;
+	  
+	  char buf[10];
+	  char slot[3];
+
+	  mach_port_t name = their_threads[index].name;
+	  
+	  mid = map_port_name_to_mid (name, MACH_TYPE_THREAD);
+	  
+	  infoCnt = THREAD_BASIC_INFO_COUNT;
+	  
+	  ret = thread_info(name,
+			    THREAD_BASIC_INFO,
+			    (thread_info_t)&ths,
+			    &infoCnt);
+	    
+	  if (ret != KERN_SUCCESS)
+	    {
+	      warning ("Unable to get basic info on thread %d : %s",
+		       mid,
+		       mach_error_string (ret));
+	      continue;
+	    }
+
+	  sprintf (slot, "%d", index%100);
+
+	  if (name == current_thread)
+	    selected = '*';
+	  else
+	    selected = ' ';
+
+	  if (ths.suspend_count)
+	    sprintf (buf, "%d", ths.suspend_count);
+	  else
+	    buf[0] = '\000';
+
+#if 0
+	  if (ths.flags & TH_FLAGS_SWAPPED)
+	    strcat (buf, "S");
+#endif
+
+	  if (ths.flags & TH_FLAGS_IDLE)
+	    strcat (buf, "I");
+
+	  printf_filtered (TL_FORMAT,
+			   slot,
+			   mid,
+			   selected,
+			   get_thread_name (NULL, index),
+			   their_threads[index].in_emulator ? "E" : "",
+			   translate_state (ths.run_state),
+			   buf,
+			   "",   /* No cproc state */
+			   "");	/* Can't be wired */
+	  print_tl_address (gdb_stdout, their_threads[index].pc);
+	  puts_filtered ("\n");
+	}
+    }
+  
+  obstack_free (cproc_obstack, 0);
+  obstack_init (cproc_obstack);
+}
+
+void
+thread_select_command(args, from_tty)
+     char *args;
+     int from_tty;
+{
+  int mid;
+  thread_array_t thread_list;
+  int thread_count;
+  kern_return_t ret;
+  int is_slot = 0;
+
+  MACH_ERROR_NO_INFERIOR;
+
+  if (!args)
+    error_no_arg ("MID or @SLOTNUMBER to specify a thread to select");
+
+  while (*args == ' ' || *args == '\t')
+    args++;
+
+  if (*args == '@')
+    {
+      is_slot++;
+      args++;
+    }
+
+  mid = atoi(args);
+
+  if (mid == 0)
+    if (!is_slot || *args != '0') /* Rudimentary checks */
+      error ("You must select threads by MID or @SLOTNUMBER");
+
+  if (select_thread (inferior_task, mid, is_slot?2:1) != KERN_SUCCESS)
+    return;
+
+  if (from_tty)
+    printf_filtered ("Thread %d selected\n",
+		     is_slot ? map_port_name_to_mid (current_thread,
+						     MACH_TYPE_THREAD) : mid);
+}
+
+thread_trace (thread, set)
+mach_port_t thread;
+boolean_t   set;
+{
+  int			flavor   = TRACE_FLAVOR;
+  unsigned int		stateCnt = TRACE_FLAVOR_SIZE;
+  kern_return_t		ret;
+  thread_state_data_t	state;
+
+  if (! MACH_PORT_VALID (thread))
+    {
+      warning ("thread_trace: invalid thread");
+      return;
+    }
+
+  if (must_suspend_thread)
+    setup_thread (thread, 1);
+
+  ret = thread_get_state(thread, flavor, state, &stateCnt);
+  CHK ("thread_trace: error reading thread state", ret);
+  
+  if (set)
+    {
+      TRACE_SET (thread, state);
+    }
+  else
+    {
+      if (! TRACE_CLEAR (thread, state))
+	{
+	  if (must_suspend_thread)
+	    setup_thread (thread, 0);
+	  return;
+	}
+    }
+
+  ret = thread_set_state(thread, flavor, state, stateCnt);
+  CHK ("thread_trace: error writing thread state", ret);
+  if (must_suspend_thread)
+    setup_thread (thread, 0);
+}  
+
+#ifdef	FLUSH_INFERIOR_CACHE
+
+/* When over-writing code on some machines the I-Cache must be flushed
+   explicitly, because it is not kept coherent by the lazy hardware.
+   This definitely includes breakpoints, for instance, or else we
+   end up looping in mysterious Bpt traps */
+
+flush_inferior_icache(pc, amount)
+     CORE_ADDR pc;
+{
+  vm_machine_attribute_val_t flush = MATTR_VAL_ICACHE_FLUSH;
+  kern_return_t   ret;
+  
+  ret = vm_machine_attribute (inferior_task,
+			      pc,
+			      amount,
+			      MATTR_CACHE,
+			      &flush);
+  if (ret != KERN_SUCCESS)
+    warning ("Error flushing inferior's cache : %s",
+	     mach_error_string (ret));
+}
+#endif	FLUSH_INFERIOR_CACHE
+
+
+static
+suspend_all_threads (from_tty)
+     int from_tty;
+{
+  kern_return_t	   ret;
+  thread_array_t   thread_list;
+  int		   thread_count, index;
+  int		   infoCnt;
+  thread_basic_info_data_t th_info;
+
+  
+  ret = task_threads (inferior_task, &thread_list, &thread_count);
+  if (ret != KERN_SUCCESS)
+    {
+      warning ("Could not suspend inferior threads.");
+      m3_kill_inferior ();
+      return_to_top_level (RETURN_ERROR);
+    }
+  
+  for (index = 0; index < thread_count; index++)
+    {
+      int mid;
+
+      mid = map_port_name_to_mid (thread_list[ index ],
+				  MACH_TYPE_THREAD);
+	  
+      ret = thread_suspend(thread_list[ index ]);
+
+      if (ret != KERN_SUCCESS)
+	warning ("Error trying to suspend thread %d : %s",
+		 mid, mach_error_string (ret));
+
+      if (from_tty)
+	{
+	  infoCnt = THREAD_BASIC_INFO_COUNT;
+	  ret = thread_info (thread_list[ index ],
+			     THREAD_BASIC_INFO,
+			     (thread_info_t) &th_info,
+			     &infoCnt);
+	  CHK ("suspend can't get thread info", ret);
+	  
+	  warning ("Thread %d suspend count is %d",
+		   mid, th_info.suspend_count);
+	}
+    }
+
+  consume_send_rights (thread_list, thread_count);
+  ret = vm_deallocate(mach_task_self(),
+		      (vm_address_t)thread_list, 
+		      (thread_count * sizeof(int)));
+  CHK ("Error trying to deallocate thread list", ret);
+}
+
+void
+thread_suspend_command (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  kern_return_t ret;
+  int           mid;
+  mach_port_t   saved_thread;
+  int           infoCnt;
+  thread_basic_info_data_t th_info;
+  
+  MACH_ERROR_NO_INFERIOR;
+
+  if (!strcasecmp (args, "all")) {
+    suspend_all_threads (from_tty);
+    return;
+  }
+
+  saved_thread = current_thread;
+
+  mid = parse_thread_id (args, 0, 0);
+
+  if (mid < 0)
+    error ("You can suspend only existing kernel threads with MID or @SLOTNUMBER");
+
+  if (mid == 0)
+    mid = map_port_name_to_mid (current_thread, MACH_TYPE_THREAD);
+  else
+    if (select_thread (inferior_task, mid, 0) != KERN_SUCCESS)
+      {
+	if (current_thread)
+	  current_thread = saved_thread;
+	error ("Could not select thread %d", mid);
+      }
+
+  ret = thread_suspend (current_thread);
+  if (ret != KERN_SUCCESS)
+    warning ("thread_suspend failed : %s",
+	     mach_error_string (ret));
+
+  infoCnt = THREAD_BASIC_INFO_COUNT;
+  ret = thread_info (current_thread,
+		     THREAD_BASIC_INFO,
+		     (thread_info_t) &th_info,
+		     &infoCnt);
+  CHK ("suspend can't get thread info", ret);
+  
+  warning ("Thread %d suspend count is %d", mid, th_info.suspend_count);
+  
+  current_thread = saved_thread;
+}
+
+resume_all_threads (from_tty)
+     int from_tty;
+{
+    kern_return_t  ret;
+    thread_array_t thread_list;
+    int		   thread_count, index;
+    int            mid;
+    int		   infoCnt;
+    thread_basic_info_data_t th_info;
+
+    ret = task_threads (inferior_task, &thread_list, &thread_count);
+    if (ret != KERN_SUCCESS)
+      {
+	m3_kill_inferior ();
+	error("task_threads", mach_error_string( ret));
+      }
+
+    for (index = 0; index < thread_count; index++)
+      {
+	infoCnt = THREAD_BASIC_INFO_COUNT;
+	ret = thread_info (thread_list [ index ],
+			   THREAD_BASIC_INFO,
+			   (thread_info_t) &th_info,
+			   &infoCnt);
+	CHK ("resume_all can't get thread info", ret);
+	
+	mid = map_port_name_to_mid (thread_list[ index ],
+				    MACH_TYPE_THREAD);
+	
+	if (! th_info.suspend_count)
+	  {
+	    if (mid != -1 && from_tty)
+	      warning ("Thread %d is not suspended", mid);
+	    continue;
+	  }
+
+	ret = thread_resume (thread_list[ index ]);
+
+	if (ret != KERN_SUCCESS)
+	  warning ("Error trying to resume thread %d : %s",
+		   mid, mach_error_string (ret));
+	else if (mid != -1 && from_tty)
+	  warning ("Thread %d suspend count is %d",
+		   mid, --th_info.suspend_count);
+      }
+
+    consume_send_rights (thread_list, thread_count);
+    ret = vm_deallocate(mach_task_self(),
+			(vm_address_t)thread_list, 
+			(thread_count * sizeof(int)));
+    CHK("Error trying to deallocate thread list", ret);
+}
+
+void
+thread_resume_command (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  int mid;
+  mach_port_t saved_thread;
+  kern_return_t ret;
+  thread_basic_info_data_t th_info;
+  int infoCnt = THREAD_BASIC_INFO_COUNT;
+  
+  MACH_ERROR_NO_INFERIOR;
+
+  if (!strcasecmp (args, "all")) {
+    resume_all_threads (from_tty);
+    return;
+  }
+
+  saved_thread = current_thread;
+
+  mid = parse_thread_id (args, 0, 0);
+
+  if (mid < 0)
+    error ("You can resume only existing kernel threads with MID or @SLOTNUMBER");
+
+  if (mid == 0)
+    mid = map_port_name_to_mid (current_thread, MACH_TYPE_THREAD);
+  else
+    if (select_thread (inferior_task, mid, 0) != KERN_SUCCESS)
+      {
+	if (current_thread)
+	  current_thread = saved_thread;
+	return_to_top_level (RETURN_ERROR);
+      }
+
+  ret = thread_info (current_thread,
+		     THREAD_BASIC_INFO,
+		     (thread_info_t) &th_info,
+		     &infoCnt);
+  CHK ("resume can't get thread info", ret);
+  
+  if (! th_info.suspend_count)
+    {
+      warning ("Thread %d is not suspended", mid);
+      goto out;
+    }
+
+  ret = thread_resume (current_thread);
+  if (ret != KERN_SUCCESS)
+    warning ("thread_resume failed : %s",
+	     mach_error_string (ret));
+  else
+    {
+      th_info.suspend_count--;
+      warning ("Thread %d suspend count is %d", mid, th_info.suspend_count);
+    }
+      
+ out:
+  current_thread = saved_thread;
+}
+
+void
+thread_kill_command (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  int mid;
+  kern_return_t ret;
+  int thread_count;
+  thread_array_t thread_table;
+  int   index;
+  mach_port_t thread_to_kill = MACH_PORT_NULL;
+  
+  
+  MACH_ERROR_NO_INFERIOR;
+
+  if (!args)
+    error_no_arg ("thread mid to kill from the inferior task");
+
+  mid = parse_thread_id (args, 0, 0);
+
+  if (mid < 0)
+    error ("You can kill only existing kernel threads with MID or @SLOTNUMBER");
+
+  if (mid)
+    {
+      ret = machid_mach_port (mid_server, mid_auth, mid, &thread_to_kill);
+      CHK ("thread_kill_command: machid_mach_port map failed", ret);
+    }
+  else
+    mid = map_port_name_to_mid (current_thread, MACH_TYPE_THREAD);
+      
+  /* Don't allow gdb to kill *any* thread in the system. Use mkill program for that */
+  ret = task_threads (inferior_task, &thread_table, &thread_count);
+  CHK ("Error getting inferior's thread list", ret);
+  
+  if (thread_to_kill == current_thread)
+    {
+      ret = thread_terminate (thread_to_kill);
+      CHK ("Thread could not be terminated", ret);
+
+      if (select_thread (inferior_task, 0, 1) != KERN_SUCCESS)
+	warning ("Last thread was killed, use \"kill\" command to kill task");
+    }
+  else
+    for (index = 0; index < thread_count; index++)
+      if (thread_table [ index ] == thread_to_kill)
+	{
+	  ret = thread_terminate (thread_to_kill);
+	  CHK ("Thread could not be terminated", ret);
+	}
+
+  if (thread_count > 1)
+    consume_send_rights (thread_table, thread_count);
+  
+  ret = vm_deallocate (mach_task_self(), (vm_address_t)thread_table, 
+		       (thread_count * sizeof(mach_port_t)));
+  CHK ("Error trying to deallocate thread list", ret);
+  
+  warning ("Thread %d killed", mid);
+}
+
+
+/* Task specific commands; add more if you like */
+
+void
+task_resume_command (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  kern_return_t ret;
+  task_basic_info_data_t ta_info;
+  int infoCnt = TASK_BASIC_INFO_COUNT;
+  int mid = map_port_name_to_mid (inferior_task, MACH_TYPE_TASK);
+  
+  MACH_ERROR_NO_INFERIOR;
+
+  /* Would be trivial to change, but is it desirable? */
+  if (args)
+    error ("Currently gdb can resume only it's inferior task");
+
+  ret = task_info (inferior_task,
+		   TASK_BASIC_INFO,
+		   (task_info_t) &ta_info,
+		   &infoCnt);
+  CHK ("task_resume_command: task_info failed", ret);
+  
+  if (ta_info.suspend_count == 0)
+    error ("Inferior task %d is not suspended", mid);
+  else if (ta_info.suspend_count == 1 &&
+	   from_tty &&
+	   !query ("Suspend count is now 1. Do you know what you are doing? "))
+    error ("Task not resumed");
+
+  ret = task_resume (inferior_task);
+  CHK ("task_resume_command: task_resume", ret);
+
+  if (ta_info.suspend_count == 1)
+    {
+      warning ("Inferior task %d is no longer suspended", mid);
+      must_suspend_thread = 1;
+      /* @@ This is not complete: Registers change all the time when not
+	 suspended! */
+      registers_changed ();
+    }
+  else
+    warning ("Inferior task %d suspend count is now %d",
+	     mid, ta_info.suspend_count-1);
+}
+
+
+void
+task_suspend_command (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  kern_return_t ret;
+  task_basic_info_data_t ta_info;
+  int infoCnt = TASK_BASIC_INFO_COUNT;
+  int mid = map_port_name_to_mid (inferior_task, MACH_TYPE_TASK);
+  
+  MACH_ERROR_NO_INFERIOR;
+
+  /* Would be trivial to change, but is it desirable? */
+  if (args)
+    error ("Currently gdb can suspend only it's inferior task");
+
+  ret = task_suspend (inferior_task);
+  CHK ("task_suspend_command: task_suspend", ret);
+
+  must_suspend_thread = 0;
+
+  ret = task_info (inferior_task,
+		   TASK_BASIC_INFO,
+		   (task_info_t) &ta_info,
+		   &infoCnt);
+  CHK ("task_suspend_command: task_info failed", ret);
+  
+  warning ("Inferior task %d suspend count is now %d",
+	   mid, ta_info.suspend_count);
+}
+
+static char *
+get_size (bytes)
+     int bytes;
+{
+  static char size [ 30 ];
+  int zz = bytes/1024;
+
+  if (zz / 1024)
+    sprintf (size, "%-2.1f M", ((float)bytes)/(1024.0*1024.0));
+  else
+    sprintf (size, "%d K", zz);
+
+  return size;
+}
+
+/* Does this require the target task to be suspended?? I don't think so. */
+void
+task_info_command (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  int mid = -5;
+  mach_port_t task;
+  kern_return_t ret;
+  task_basic_info_data_t ta_info;
+  int infoCnt = TASK_BASIC_INFO_COUNT;
+  int page_size = round_page(1);
+  int thread_count = 0;
+  
+  if (MACH_PORT_VALID (inferior_task))
+    mid = map_port_name_to_mid (inferior_task,
+				MACH_TYPE_TASK);
+
+  task = inferior_task;
+
+  if (args)
+    {
+      int tmid = atoi (args);
+
+      if (tmid <= 0)
+	error ("Invalid mid %d for task info", tmid);
+
+      if (tmid != mid)
+	{
+	  mid = tmid;
+	  ret = machid_mach_port (mid_server, mid_auth, tmid, &task);
+	  CHK ("task_info_command: machid_mach_port map failed", ret);
+	}
+    }
+
+  if (mid < 0)
+    error ("You have to give the task MID as an argument");
+
+  ret = task_info (task,
+		   TASK_BASIC_INFO,
+		   (task_info_t) &ta_info,
+		   &infoCnt);
+  CHK ("task_info_command: task_info failed", ret);
+
+  printf_filtered ("\nTask info for task %d:\n\n", mid);
+  printf_filtered (" Suspend count : %d\n", ta_info.suspend_count);
+  printf_filtered (" Base priority : %d\n", ta_info.base_priority);
+  printf_filtered (" Virtual size  : %s\n", get_size (ta_info.virtual_size));
+  printf_filtered (" Resident size : %s\n", get_size (ta_info.resident_size));
+
+  {
+    thread_array_t thread_list;
+    
+    ret = task_threads (task, &thread_list, &thread_count);
+    CHK ("task_info_command: task_threads", ret);
+    
+    printf_filtered (" Thread count  : %d\n", thread_count);
+
+    consume_send_rights (thread_list, thread_count);
+    ret = vm_deallocate(mach_task_self(),
+			(vm_address_t)thread_list, 
+			(thread_count * sizeof(int)));
+    CHK("Error trying to deallocate thread list", ret);
+  }
+  if (have_emulator_p (task))
+    printf_filtered (" Emulator at   : 0x%x..0x%x\n",
+		     EMULATOR_BASE, EMULATOR_END);
+  else
+    printf_filtered (" No emulator.\n");
+
+  if (thread_count && task == inferior_task)
+    printf_filtered ("\nUse the \"thread list\" command to see the threads\n");
+}
+
+/* You may either FORWARD the exception to the inferior, or KEEP
+ * it and return to GDB command level.
+ *
+ * exception mid [ forward | keep ]
+ */
+
+static void
+exception_command (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  char *scan = args;
+  int exception;
+  int len;
+
+  if (!args)
+    error_no_arg ("exception number action");
+
+  while (*scan == ' ' || *scan == '\t') scan++;
+  
+  if ('0' <= *scan && *scan <= '9')
+    while ('0' <= *scan && *scan <= '9')
+      scan++;
+  else
+    error ("exception number action");
+
+  exception = atoi (args);
+  if (exception <= 0 || exception > MAX_EXCEPTION)
+    error ("Allowed exception numbers are in range 1..%d",
+	   MAX_EXCEPTION);
+
+  if (*scan != ' ' && *scan != '\t')
+    error ("exception number must be followed by a space");
+  else
+    while (*scan == ' ' || *scan == '\t') scan++;
+
+  args = scan;
+  len = 0;
+  while (*scan)
+    {
+      len++;
+      scan++;
+    }
+
+  if (!len)
+    error("exception number action");
+
+  if (!strncasecmp (args, "forward", len))
+    exception_map[ exception ].forward = TRUE;
+  else if (!strncasecmp (args, "keep", len))
+    exception_map[ exception ].forward = FALSE;
+  else
+    error ("exception action is either \"keep\" or \"forward\"");
+}
+
+static void
+print_exception_info (exception)
+     int exception;
+{
+  boolean_t forward = exception_map[ exception ].forward;
+
+  printf_filtered ("%s\t(%d): ", exception_map[ exception ].name,
+		   exception);
+  if (!forward)
+    if (exception_map[ exception ].sigmap != SIG_UNKNOWN)
+      printf_filtered ("keep and handle as signal %d\n",
+		       exception_map[ exception ].sigmap);
+    else
+      printf_filtered ("keep and handle as unknown signal %d\n",
+		       exception_map[ exception ].sigmap);
+  else
+    printf_filtered ("forward exception to inferior\n");
+}
+
+void
+exception_info (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  int exception;
+
+  if (!args)
+    for (exception = 1; exception <= MAX_EXCEPTION; exception++)
+      print_exception_info (exception);
+  else
+    {
+      exception = atoi (args);
+
+      if (exception <= 0 || exception > MAX_EXCEPTION)
+	error ("Invalid exception number, values from 1 to %d allowed",
+	       MAX_EXCEPTION);
+      print_exception_info (exception);
+    }
+}
+
+/* Check for actions for mach exceptions.
+ */
+mach3_exception_actions (w, force_print_only, who)
+     WAITTYPE *w;
+     boolean_t force_print_only;
+     char *who;
+{
+  boolean_t force_print = FALSE;
+
+  
+  if (force_print_only ||
+      exception_map[stop_exception].sigmap == SIG_UNKNOWN)
+    force_print = TRUE;
+  else
+    WSETSTOP (*w, exception_map[stop_exception].sigmap);
+
+  if (exception_map[stop_exception].print || force_print)
+    {
+      target_terminal_ours ();
+      
+      printf_filtered ("\n%s received %s exception : ",
+		       who,
+		       exception_map[stop_exception].name);
+      
+      wrap_here ("   ");
+
+      switch(stop_exception) {
+      case EXC_BAD_ACCESS:
+	printf_filtered ("referencing address 0x%x : %s\n",
+			 stop_subcode,
+			 mach_error_string (stop_code));
+	break;
+      case EXC_BAD_INSTRUCTION:
+	printf_filtered
+	  ("illegal or undefined instruction. code %d subcode %d\n",
+	   stop_code, stop_subcode);
+	break;
+      case EXC_ARITHMETIC:
+	printf_filtered ("code %d\n", stop_code);
+	break;
+      case EXC_EMULATION:
+	printf_filtered ("code %d subcode %d\n", stop_code, stop_subcode);
+	break;
+      case EXC_SOFTWARE:
+	printf_filtered ("%s specific, code 0x%x\n",
+			 stop_code < 0xffff ? "hardware" : "os emulation",
+			 stop_code);
+	break;
+      case EXC_BREAKPOINT:
+	printf_filtered ("type %d (machine dependent)\n",
+			 stop_code);
+	break;
+      default:
+	fatal ("Unknown exception");
+      }
+    }
+}
+
+setup_notify_port (create_new)
+     int create_new;
+{
+  kern_return_t ret;
+
+  if (MACH_PORT_VALID (our_notify_port))
+    {
+      ret = mach_port_destroy (mach_task_self (), our_notify_port);
+      CHK ("Could not destroy our_notify_port", ret);
+    }
+
+  our_notify_port = MACH_PORT_NULL;
+  notify_chain    = (port_chain_t) NULL;
+  port_chain_destroy (port_chain_obstack);
+
+  if (create_new)
+    {
+      ret = mach_port_allocate (mach_task_self(),
+				MACH_PORT_RIGHT_RECEIVE,
+				&our_notify_port);
+      if (ret != KERN_SUCCESS)
+	fatal("Creating notify port %s", mach_error_string(ret));
+      
+      ret = mach_port_move_member(mach_task_self(), 
+				  our_notify_port,
+				  inferior_wait_port_set);
+      if (ret != KERN_SUCCESS)
+	fatal("initial move member %s",mach_error_string(ret));
+    }
+}
+
+/*
+ * Register our message port to the net name server
+ *
+ * Currently used only by the external stop-gdb program
+ * since ^C does not work if you would like to enter
+ * gdb command level while debugging your program.
+ *
+ * NOTE: If the message port is sometimes used for other
+ * purposes also, the NAME must not be a guessable one.
+ * Then, there should be a way to change it.
+ */
+
+char registered_name[ MAX_NAME_LEN ];
+
+void
+message_port_info (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  if (registered_name[0])
+    printf_filtered ("gdb's message port name: '%s'\n",
+		     registered_name);
+  else
+    printf_filtered ("gdb's message port is not currently registered\n");
+}
+
+void
+gdb_register_port (name, port)
+     char *name;
+     mach_port_t port;
+{
+  kern_return_t ret;
+  static int already_signed = 0;
+  int len;
+
+  if (! MACH_PORT_VALID (port) || !name || !*name)
+    {
+      warning ("Invalid registration request");
+      return;
+    }
+
+  if (! already_signed)
+    {
+      ret = mach_port_insert_right (mach_task_self (),
+				    our_message_port,
+				    our_message_port,
+				    MACH_MSG_TYPE_MAKE_SEND);
+      CHK ("Failed to create a signature to our_message_port", ret);
+      already_signed = 1;
+    }
+  else if (already_signed > 1)
+    {
+      ret = netname_check_out (name_server_port,
+			       registered_name,
+			       our_message_port);
+      CHK ("Failed to check out gdb's message port", ret);
+      registered_name[0] = '\000';
+      already_signed = 1;
+    }
+
+  ret = netname_check_in (name_server_port,	/* Name server port */
+			  name,			/* Name of service */
+			  our_message_port,	/* Signature */
+			  port); 		/* Creates a new send right */
+  CHK("Failed to check in the port", ret);
+  
+  len = 0;
+  while(len < MAX_NAME_LEN && *(name+len))
+    {
+      registered_name[len] = *(name+len);
+      len++;
+    }
+  registered_name[len] = '\000';
+  already_signed = 2;
+}  
+
+struct cmd_list_element *cmd_thread_list;
+struct cmd_list_element *cmd_task_list;
+
+/*ARGSUSED*/
+static void
+thread_command (arg, from_tty)
+     char *arg;
+     int from_tty;
+{
+  printf_unfiltered ("\"thread\" must be followed by the name of a thread command.\n");
+  help_list (cmd_thread_list, "thread ", -1, gdb_stdout);
+}
+
+/*ARGSUSED*/
+static void
+task_command (arg, from_tty)
+     char *arg;
+     int from_tty;
+{
+  printf_unfiltered ("\"task\" must be followed by the name of a task command.\n");
+  help_list (cmd_task_list, "task ", -1, gdb_stdout);
+}
+
+add_mach_specific_commands ()
+{
+  /* Thread handling commands */
+
+  /* FIXME: Move our thread support into the generic thread.c stuff so we
+     can share that code.  */
+  add_prefix_cmd ("mthread", class_stack, thread_command,
+      "Generic command for handling Mach threads in the debugged task.",
+      &cmd_thread_list, "thread ", 0, &cmdlist);
+
+  add_com_alias ("th", "mthread", class_stack, 1);
+
+  add_cmd ("select", class_stack, thread_select_command, 
+	   "Select and print MID of the selected thread",
+	   &cmd_thread_list);
+  add_cmd ("list",   class_stack, thread_list_command,
+	   "List info of task's threads. Selected thread is marked with '*'",
+	   &cmd_thread_list);
+  add_cmd ("suspend", class_run, thread_suspend_command,
+	   "Suspend one or all of the threads in the selected task.",
+	   &cmd_thread_list);
+  add_cmd ("resume", class_run, thread_resume_command,
+	   "Resume one or all of the threads in the selected task.",
+	   &cmd_thread_list);
+  add_cmd ("kill", class_run, thread_kill_command,
+	   "Kill the specified thread MID from inferior task.",
+	   &cmd_thread_list);
+#if 0
+  /* The rest of this support (condition_thread) was not merged.  It probably
+     should not be merged in this form, but instead added to the generic GDB
+     thread support.  */
+  add_cmd ("break", class_breakpoint, condition_thread,
+	   "Breakpoint N will only be effective for thread MID or @SLOT\n\
+	    If MID/@SLOT is omitted allow all threads to break at breakpoint",
+	   &cmd_thread_list);
+#endif
+  /* Thread command shorthands (for backward compatibility) */
+  add_alias_cmd ("ts", "mthread select", 0, 0, &cmdlist);
+  add_alias_cmd ("tl", "mthread list",   0, 0, &cmdlist);
+
+  /* task handling commands */
+
+  add_prefix_cmd ("task", class_stack, task_command,
+      "Generic command for handling debugged task.",
+      &cmd_task_list, "task ", 0, &cmdlist);
+
+  add_com_alias ("ta", "task", class_stack, 1);
+
+  add_cmd ("suspend", class_run, task_suspend_command,
+	   "Suspend the inferior task.",
+	   &cmd_task_list);
+  add_cmd ("resume", class_run, task_resume_command,
+	   "Resume the inferior task.",
+	   &cmd_task_list);
+  add_cmd ("info", no_class, task_info_command,
+	   "Print information about the specified task.",
+	   &cmd_task_list);
+
+  /* Print my message port name */
+
+  add_info ("message-port", message_port_info,
+	    "Returns the name of gdb's message port in the netnameserver");
+
+  /* Exception commands */
+
+  add_info ("exceptions", exception_info,
+	    "What debugger does when program gets various exceptions.\n\
+Specify an exception number as argument to print info on that\n\
+exception only.");
+
+  add_com ("exception", class_run, exception_command,
+	   "Specify how to handle an exception.\n\
+Args are exception number followed by \"forward\" or \"keep\".\n\
+`Forward' means forward the exception to the program's normal exception\n\
+handler.\n\
+`Keep' means reenter debugger if this exception happens, and GDB maps\n\
+the exception to some signal (see info exception)\n\
+Normally \"keep\" is used to return to GDB on exception.");
+}
+
+kern_return_t
+do_mach_notify_dead_name (notify, name)
+     mach_port_t notify;
+     mach_port_t name;
+{
+  kern_return_t kr = KERN_SUCCESS;
+
+  /* Find the thing that notified */
+  port_chain_t element = port_chain_member (notify_chain, name);
+
+  /* Take name of from unreceived dead name notification list */
+  notify_chain = port_chain_delete (notify_chain, name);
+
+  if (! element)
+    error ("Received a dead name notify from unchained port (0x%x)", name);
+  
+  switch (element->type) {
+
+  case MACH_TYPE_THREAD:
+    target_terminal_ours_for_output ();
+    if (name == current_thread)
+      {
+	printf_filtered ("\nCurrent thread %d died", element->mid);
+	current_thread = MACH_PORT_NULL;
+      }
+    else
+      printf_filtered ("\nThread %d died", element->mid);
+
+    break;
+
+  case MACH_TYPE_TASK:
+    target_terminal_ours_for_output ();
+    if (name != inferior_task)
+      printf_filtered ("Task %d died, but it was not the selected task",
+	       element->mid);
+    else	       
+      {
+	printf_filtered ("Current task %d died", element->mid);
+	
+	mach_port_destroy (mach_task_self(), name);
+	inferior_task = MACH_PORT_NULL;
+	
+	if (notify_chain)
+	  warning ("There were still unreceived dead_name_notifications???");
+	
+	/* Destroy the old notifications */
+	setup_notify_port (0);
+
+      }
+    break;
+
+  default:
+    error ("Unregistered dead_name 0x%x notification received. Type is %d, mid is 0x%x",
+	   name, element->type, element->mid);
+    break;
+  }
+
+  return KERN_SUCCESS;
+}
+
+kern_return_t
+do_mach_notify_msg_accepted (notify, name)
+     mach_port_t notify;
+     mach_port_t name;
+{
+  warning ("do_mach_notify_msg_accepted : notify %x, name %x",
+	   notify, name);
+  return KERN_SUCCESS;
+}
+
+kern_return_t
+do_mach_notify_no_senders (notify, mscount)
+     mach_port_t notify;
+     mach_port_mscount_t mscount;
+{
+  warning ("do_mach_notify_no_senders : notify %x, mscount %x",
+	   notify, mscount);
+  return KERN_SUCCESS;
+}
+
+kern_return_t
+do_mach_notify_port_deleted (notify, name)
+     mach_port_t notify;
+     mach_port_t name;
+{
+  warning ("do_mach_notify_port_deleted : notify %x, name %x",
+	   notify, name);
+  return KERN_SUCCESS;
+}
+
+kern_return_t
+do_mach_notify_port_destroyed (notify, rights)
+     mach_port_t notify;
+     mach_port_t rights;
+{
+  warning ("do_mach_notify_port_destroyed : notify %x, rights %x",
+	   notify, rights);
+  return KERN_SUCCESS;
+}
+
+kern_return_t
+do_mach_notify_send_once (notify)
+     mach_port_t notify;
+{
+#ifdef DUMP_SYSCALL
+  /* MANY of these are generated. */
+  warning ("do_mach_notify_send_once : notify %x",
+	   notify);
+#endif
+  return KERN_SUCCESS;
+}
+
+/* Kills the inferior. It's gone when you call this */
+static void
+kill_inferior_fast ()
+{
+  WAITTYPE w;
+
+  if (inferior_pid == 0 || inferior_pid == 1)
+    return;
+
+  /* kill() it, since the Unix server does not otherwise notice when
+   * killed with task_terminate().
+   */
+  if (inferior_pid > 0)
+    kill (inferior_pid, SIGKILL);
+
+  /* It's propably terminate already */
+  (void) task_terminate (inferior_task);
+
+  inferior_task  = MACH_PORT_NULL;
+  current_thread = MACH_PORT_NULL;
+
+  wait3 (&w, WNOHANG, 0);
+
+  setup_notify_port (0);
+}
+
+static void
+m3_kill_inferior ()
+{
+  kill_inferior_fast ();
+  target_mourn_inferior ();
+}
+
+/* Clean up after the inferior dies.  */
+
+static void
+m3_mourn_inferior ()
+{
+  unpush_target (&m3_ops);
+  generic_mourn_inferior ();
+}
+
+
+/* Fork an inferior process, and start debugging it.  */
+
+static void
+m3_create_inferior (exec_file, allargs, env)
+     char *exec_file;
+     char *allargs;
+     char **env;
+{
+  fork_inferior (exec_file, allargs, env, m3_trace_me, m3_trace_him, NULL, NULL);
+  /* We are at the first instruction we care about.  */
+  /* Pedal to the metal... */
+  proceed ((CORE_ADDR) -1, 0, 0);
+}
+
+/* Mark our target-struct as eligible for stray "run" and "attach"
+   commands.  */
+static int
+m3_can_run ()
+{
+  return 1;
+}
+
+/* Mach 3.0 does not need ptrace for anything
+ * Make sure nobody uses it on mach.
+ */
+ptrace (a,b,c,d)
+int a,b,c,d;
+{
+  error ("Lose, Lose! Somebody called ptrace\n");
+}
+
+/* Resume execution of the inferior process.
+   If STEP is nonzero, single-step it.
+   If SIGNAL is nonzero, give it that signal.  */
+
+void
+m3_resume (pid, step, signal)
+     int pid;
+     int step;
+     enum target_signal signal;
+{
+  kern_return_t	ret;
+
+  if (step)
+    {
+      thread_basic_info_data_t th_info;
+      unsigned int	       infoCnt = THREAD_BASIC_INFO_COUNT;
+      
+      /* There is no point in single stepping when current_thread
+       * is dead.
+       */
+      if (! MACH_PORT_VALID (current_thread))
+	error ("No thread selected; can not single step");
+      
+      /* If current_thread is suspended, tracing it would never return.
+       */
+      ret = thread_info (current_thread,
+			 THREAD_BASIC_INFO,
+			 (thread_info_t) &th_info,
+			 &infoCnt);
+      CHK ("child_resume: can't get thread info", ret);
+      
+      if (th_info.suspend_count)
+	error ("Can't trace a suspended thread. Use \"thread resume\" command to resume it");
+    }
+
+  vm_read_cache_valid = FALSE;
+
+  if (signal && inferior_pid > 0) /* Do not signal, if attached by MID */
+    kill (inferior_pid, target_signal_to_host (signal));
+
+  if (step)
+    {
+      suspend_all_threads (0);
+
+      setup_single_step (current_thread, TRUE);
+      
+      ret = thread_resume (current_thread);
+      CHK ("thread_resume", ret);
+    }
+  
+  ret = task_resume (inferior_task);
+  if (ret == KERN_FAILURE)
+    warning ("Task was not suspended");
+  else
+    CHK ("Resuming task", ret);
+  
+  /* HACK HACK This is needed by the multiserver system HACK HACK */
+  while ((ret = task_resume(inferior_task)) == KERN_SUCCESS)
+    /* make sure it really runs */;
+  /* HACK HACK This is needed by the multiserver system HACK HACK */
+}
+
+#ifdef ATTACH_DETACH
+
+/* Start debugging the process with the given task */
+void
+task_attach (tid)
+  task_t tid;
+{
+  kern_return_t ret;
+  inferior_task = tid;
+
+  ret = task_suspend (inferior_task);
+  CHK("task_attach: task_suspend", ret);
+
+  must_suspend_thread = 0;
+
+  setup_notify_port (1);
+
+  request_notify (inferior_task, MACH_NOTIFY_DEAD_NAME, MACH_TYPE_TASK);
+
+  setup_exception_port ();
+  
+  emulator_present = have_emulator_p (inferior_task);
+
+  attach_flag = 1;
+}
+
+/* Well, we can call error also here and leave the
+ * target stack inconsistent. Sigh.
+ * Fix this sometime (the only way to fail here is that
+ * the task has no threads at all, which is rare, but
+ * possible; or if the target task has died, which is also
+ * possible, but unlikely, since it has been suspended.
+ * (Someone must have killed it))
+ */
+void
+attach_to_thread ()
+{
+  if (select_thread (inferior_task, 0, 1) != KERN_SUCCESS)
+    error ("Could not select any threads to attach to");
+}
+
+mid_attach (mid)
+    int	mid;
+{
+    kern_return_t ret;
+
+    ret = machid_mach_port (mid_server, mid_auth, mid, &inferior_task);
+    CHK("mid_attach: machid_mach_port", ret);
+
+    task_attach (inferior_task);
+
+    return mid;
+}
+
+/* 
+ * Start debugging the process whose unix process-id is PID.
+ * A negative "pid" value is legal and signifies a mach_id not a unix pid.
+ *
+ * Prevent (possible unwanted) dangerous operations by enabled users
+ * like "atta 0" or "atta foo" (equal to the previous :-) and
+ * "atta pidself". Anyway, the latter is allowed by specifying a MID.
+ */
+static int
+m3_do_attach (pid)
+     int pid;
+{
+  kern_return_t ret;
+
+  if (pid == 0)
+    error("MID=0, Debugging the master unix server does not compute");
+
+  /* Foo. This assumes gdb has a unix pid */
+  if (pid == getpid())
+    error ("I will debug myself only by mid. (Gdb would suspend itself!)");
+
+  if (pid < 0)
+    {
+      mid_attach (-(pid));
+
+      /* inferior_pid will be NEGATIVE! */
+      inferior_pid = pid;
+
+      return inferior_pid;
+    }
+
+  inferior_task = task_by_pid (pid);
+  if (! MACH_PORT_VALID (inferior_task))
+    error("Cannot map Unix pid %d to Mach task port", pid);
+
+  task_attach (inferior_task);
+
+  inferior_pid = pid;
+
+  return inferior_pid;
+}
+
+/* Attach to process PID, then initialize for debugging it
+   and wait for the trace-trap that results from attaching.  */
+
+static void
+m3_attach (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  char *exec_file;
+  int pid;
+
+  if (!args)
+    error_no_arg ("process-id to attach");
+
+  pid = atoi (args);
+
+  if (pid == getpid())		/* Trying to masturbate? */
+    error ("I refuse to debug myself!");
+
+  if (from_tty)
+    {
+      exec_file = (char *) get_exec_file (0);
+
+      if (exec_file)
+	printf_unfiltered ("Attaching to program `%s', %s\n", exec_file, target_pid_to_str (pid));
+      else
+	printf_unfiltered ("Attaching to %s\n", target_pid_to_str (pid));
+
+      gdb_flush (gdb_stdout);
+    }
+
+  m3_do_attach (pid);
+  inferior_pid = pid;
+  push_target (&m3_ops);
+}
+
+void
+deallocate_inferior_ports ()
+{
+  kern_return_t  ret;
+  thread_array_t thread_list;
+  int		 thread_count, index;
+
+  if (!MACH_PORT_VALID (inferior_task))
+    return;
+
+  ret = task_threads (inferior_task, &thread_list, &thread_count);
+  if (ret != KERN_SUCCESS)
+    {
+      warning ("deallocate_inferior_ports: task_threads",
+	       mach_error_string(ret));
+      return;
+    }
+
+  /* Get rid of send rights to task threads */
+  for (index = 0; index < thread_count; index++)
+    {
+      int rights;
+      ret = mach_port_get_refs (mach_task_self (),
+				thread_list[index],
+				MACH_PORT_RIGHT_SEND,
+				&rights);
+      CHK("deallocate_inferior_ports: get refs", ret);
+
+      if (rights > 0)
+	{
+	  ret = mach_port_mod_refs (mach_task_self (),
+				    thread_list[index],
+				    MACH_PORT_RIGHT_SEND,
+				    -rights);
+	  CHK("deallocate_inferior_ports: mod refs", ret);
+	}
+    }
+
+  ret = mach_port_mod_refs (mach_task_self (),
+			    inferior_exception_port,
+			    MACH_PORT_RIGHT_RECEIVE,
+			    -1);
+  CHK ("deallocate_inferior_ports: cannot get rid of exception port", ret);
+
+  ret = mach_port_deallocate (mach_task_self (),
+			      inferior_task);
+  CHK ("deallocate_task_port: deallocating inferior_task", ret);
+
+  current_thread = MACH_PORT_NULL;
+  inferior_task  = MACH_PORT_NULL;
+}
+
+/* Stop debugging the process whose number is PID
+   and continue it with signal number SIGNAL.
+   SIGNAL = 0 means just continue it.  */
+
+static void
+m3_do_detach (signal)
+     int signal;
+{
+  kern_return_t ret;
+
+  MACH_ERROR_NO_INFERIOR;
+
+  if (current_thread != MACH_PORT_NULL)
+    {
+      /* Store the gdb's view of the thread we are deselecting
+       * before we detach.
+       * @@ I am really not sure if this is ever needeed.
+       */
+      target_prepare_to_store ();
+      target_store_registers (-1);
+    }
+
+  ret = task_set_special_port (inferior_task,
+			       TASK_EXCEPTION_PORT, 
+			       inferior_old_exception_port);
+  CHK ("task_set_special_port", ret);
+
+  /* Discard all requested notifications */
+  setup_notify_port (0);
+
+  if (remove_breakpoints ())
+    warning ("Could not remove breakpoints when detaching");
+  
+  if (signal && inferior_pid > 0)
+    kill (inferior_pid, signal);
+  
+  /* the task might be dead by now */
+  (void) task_resume (inferior_task);
+  
+  deallocate_inferior_ports ();
+  
+  attach_flag = 0;
+}
+
+/* Take a program previously attached to and detaches it.
+   The program resumes execution and will no longer stop
+   on signals, etc.  We'd better not have left any breakpoints
+   in the program or it'll die when it hits one.  For this
+   to work, it may be necessary for the process to have been
+   previously attached.  It *might* work if the program was
+   started via fork.  */
+
+static void
+m3_detach (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  int siggnal = 0;
+
+  if (from_tty)
+    {
+      char *exec_file = get_exec_file (0);
+      if (exec_file == 0)
+	exec_file = "";
+      printf_unfiltered ("Detaching from program: %s %s\n",
+	      exec_file, target_pid_to_str (inferior_pid));
+      gdb_flush (gdb_stdout);
+    }
+  if (args)
+    siggnal = atoi (args);
+  
+  m3_do_detach (siggnal);
+  inferior_pid = 0;
+  unpush_target (&m3_ops);		/* Pop out of handling an inferior */
+}
+#endif /* ATTACH_DETACH */
+
+/* Get ready to modify the registers array.  On machines which store
+   individual registers, this doesn't need to do anything.  On machines
+   which store all the registers in one fell swoop, this makes sure
+   that registers contains all the registers from the program being
+   debugged.  */
+
+static void
+m3_prepare_to_store ()
+{
+#ifdef CHILD_PREPARE_TO_STORE
+  CHILD_PREPARE_TO_STORE ();
+#endif
+}
+
+/* Print status information about what we're accessing.  */
+
+static void
+m3_files_info (ignore)
+     struct target_ops *ignore;
+{
+  /* FIXME: should print MID and all that crap.  */
+  printf_unfiltered ("\tUsing the running image of %s %s.\n",
+		       attach_flag? "attached": "child", target_pid_to_str (inferior_pid));
+}
+
+static void
+m3_open (arg, from_tty)
+     char *arg;
+     int from_tty;
+{
+  error ("Use the \"run\" command to start a Unix child process.");
+}
+
+#ifdef DUMP_SYSCALL
+#ifdef __STDC__
+#define STR(x) #x
+#else
+#define STR(x) "x"
+#endif
+
+char	*bsd1_names[] = {
+  "execve",
+  "fork",
+  "take_signal",
+  "sigreturn",
+  "getrusage",
+  "chdir",
+  "chroot",
+  "open",
+  "creat",
+  "mknod",
+  "link",
+  "symlink",
+  "unlink",
+  "access",
+  "stat",
+  "readlink",
+  "chmod",
+  "chown",
+  "utimes",
+  "truncate",
+  "rename",
+  "mkdir",
+  "rmdir",
+  "xutimes",
+  "mount",
+  "umount",
+  "acct",
+  "setquota",
+  "write_short",
+  "write_long",
+  "send_short",
+  "send_long",
+  "sendto_short",
+  "sendto_long",
+  "select",
+  "task_by_pid",
+  "recvfrom_short",
+  "recvfrom_long",
+  "setgroups",
+  "setrlimit",
+  "sigvec",
+  "sigstack",
+  "settimeofday",
+  "adjtime",
+  "setitimer",
+  "sethostname",
+  "bind",
+  "accept",
+  "connect",
+  "setsockopt",
+  "getsockopt",
+  "getsockname",
+  "getpeername",
+  "init_process",
+  "table_set",
+  "table_get",
+  "pioctl",
+  "emulator_error",
+  "readwrite",
+  "share_wakeup",
+  0,
+  "maprw_request_it",
+  "maprw_release_it",
+  "maprw_remap",
+  "pid_by_task",
+};
+
+int	bsd1_nnames = sizeof(bsd1_names)/sizeof(bsd1_names[0]);
+
+char*
+name_str(name,buf)
+
+int	name;
+char	*buf;
+
+{
+  switch (name) {
+  case MACH_MSG_TYPE_BOOLEAN:
+    return "boolean";
+  case MACH_MSG_TYPE_INTEGER_16:
+    return "short";
+  case MACH_MSG_TYPE_INTEGER_32:
+    return "long";
+  case MACH_MSG_TYPE_CHAR:
+    return "char";
+  case MACH_MSG_TYPE_BYTE:
+    return "byte";
+  case MACH_MSG_TYPE_REAL:
+    return "real";
+  case MACH_MSG_TYPE_STRING:
+    return "string";
+  default:
+    sprintf(buf,"%d",name);
+    return buf;
+  }
+}
+
+char *
+id_str(id,buf)
+
+int	id;
+char	*buf;
+
+{
+  char	*p;
+  if (id >= 101000 && id < 101000+bsd1_nnames) {
+    if (p = bsd1_names[id-101000])
+      return p;
+  }
+  if (id == 102000)
+    return "psignal_retry";
+  if (id == 100000)
+    return "syscall";
+  sprintf(buf,"%d",id);
+  return buf;
+}
+
+print_msg(mp)
+mach_msg_header_t	*mp;
+{
+  char	*fmt_x = "%20s : 0x%08x\n";
+  char	*fmt_d = "%20s : %10d\n";
+  char	*fmt_s = "%20s : %s\n";
+  char	buf[100];
+
+  puts_filtered ("\n");
+#define pr(fmt,h,x) printf_filtered(fmt,STR(x),(h).x)
+  pr(fmt_x,(*mp),msgh_bits);
+  pr(fmt_d,(*mp),msgh_size);
+  pr(fmt_x,(*mp),msgh_remote_port);
+  pr(fmt_x,(*mp),msgh_local_port);
+  pr(fmt_d,(*mp),msgh_kind);
+  printf_filtered(fmt_s,STR(msgh_id),id_str(mp->msgh_id,buf));
+  
+  if (debug_level > 1)
+  {
+    char	*p,*ep,*dp;
+    int		plen;
+    p = (char*)mp;
+    ep = p+mp->msgh_size;
+    p += sizeof(*mp);
+    for(; p < ep; p += plen) {
+      mach_msg_type_t	*tp;
+      mach_msg_type_long_t	*tlp;
+      int	name,size,number;
+      tp = (mach_msg_type_t*)p;
+      if (tp->msgt_longform) {
+	tlp = (mach_msg_type_long_t*)tp;
+	name = tlp->msgtl_name;
+	size = tlp->msgtl_size;
+	number = tlp->msgtl_number;
+	plen = sizeof(*tlp);
+      } else {
+	name = tp->msgt_name;
+	size = tp->msgt_size;
+	number = tp->msgt_number;
+	plen = sizeof(*tp);
+      }
+      printf_filtered("name=%-16s size=%2d number=%7d inline=%d long=%d deal=%d\n",
+		      name_str(name,buf),size,number,tp->msgt_inline,
+		      tp->msgt_longform, tp->msgt_deallocate);
+      dp = p+plen;
+      if (tp->msgt_inline) {
+	int	l;
+	l = size*number/8;
+	l = (l+sizeof(long)-1)&~((sizeof(long))-1);
+	plen += l;
+	print_data(dp,size,number);
+      } else {
+	plen += sizeof(int*);
+      }
+      printf_filtered("plen=%d\n",plen);
+    }
+  }
+}
+
+print_data(p,size,number)
+
+char	*p;
+
+{
+  int	*ip;
+  short	*sp;
+  int	i;
+
+  switch (size) {
+  case 8:
+    for(i = 0; i < number; i++) {
+      printf_filtered(" %02x",p[i]);
+    }
+    break;
+  case 16:
+    sp = (short*)p;
+    for(i = 0; i < number; i++) {
+      printf_filtered(" %04x",sp[i]);
+    }
+    break;
+  case 32:
+    ip = (int*)p;
+    for(i = 0; i < number; i++) {
+      printf_filtered(" %08x",ip[i]);
+    }
+    break;
+  }
+  puts_filtered("\n");
+}
+#endif  DUMP_SYSCALL
+
+static void
+m3_stop ()
+{
+  error ("to_stop target function not implemented");
+}
+
+static char *
+m3_pid_to_exec_file (pid)
+int  pid;
+{
+  error ("to_pid_to_exec_file target function not implemented");
+  return NULL;  /* To keep all compilers happy. */
+}
+
+static void
+init_m3_ops ()
+{
+  m3_ops.to_shortname = "mach";
+  m3_ops.to_longname = "Mach child process";
+  m3_ops.to_doc = "Mach child process (started by the \"run\" command).";
+  m3_ops.to_open = m3_open;
+  m3_ops.to_attach = m3_attach;
+  m3_ops.to_detach = m3_detach;
+  m3_ops.to_resume = m3_resume;
+  m3_ops.to_wait = mach_really__wait;
+  m3_ops.to_fetch_registers = fetch_inferior_registers;
+  m3_ops.to_store_registers = store_inferior_registers;
+  m3_ops.to_prepare_to_store = m3_prepare_to_store;
+  m3_ops.to_xfer_memory = m3_xfer_memory;
+  m3_ops.to_files_info = m3_files_info;
+  m3_ops.to_insert_breakpoint = memory_insert_breakpoint;
+  m3_ops.to_remove_breakpoint = memory_remove_breakpoint;
+  m3_ops.to_terminal_init = terminal_init_inferior;
+  m3_ops.to_terminal_inferior = terminal_inferior;
+  m3_ops.to_terminal_ours_for_output = terminal_ours_for_output;
+  m3_ops.to_terminal_ours = terminal_ours;
+  m3_ops.to_terminal_info = child_terminal_info;
+  m3_ops.to_kill = m3_kill_inferior;
+  m3_ops.to_create_inferior = m3_create_inferior;
+  m3_ops.to_mourn_inferior = m3_mourn_inferior;
+  m3_ops.to_can_run = m3_can_run;
+  m3_ops.to_stop = m3_stop;
+  m3_ops.to_pid_to_exec_file = m3_pid_to_exec_file;
+  m3_ops.to_stratum = process_stratum;
+  m3_ops.to_has_all_memory = 1;
+  m3_ops.to_has_memory = 1;
+  m3_ops.to_has_stack = 1;
+  m3_ops.to_has_registers = 1;
+  m3_ops.to_has_execution = 1;
+  m3_ops.to_magic = OPS_MAGIC;
+}
+
+void
+_initialize_m3_nat ()
+{
+  kern_return_t ret;
+
+  init_m3_ops ();
+  add_target (&m3_ops);
+
+  ret = mach_port_allocate(mach_task_self(), 
+			   MACH_PORT_RIGHT_PORT_SET,
+			   &inferior_wait_port_set);
+  if (ret != KERN_SUCCESS)
+    fatal("initial port set %s",mach_error_string(ret));
+
+  /* mach_really_wait now waits for this */
+  currently_waiting_for = inferior_wait_port_set;
+
+  ret = netname_look_up(name_server_port, hostname, "MachID", &mid_server);
+  if (ret != KERN_SUCCESS)
+    {
+      mid_server = MACH_PORT_NULL;
+      
+      warning ("initialize machid: netname_lookup_up(MachID) : %s",
+	       mach_error_string(ret));
+      warning ("Some (most?) features disabled...");
+    }
+  
+  mid_auth = mach_privileged_host_port();
+  if (mid_auth == MACH_PORT_NULL)
+    mid_auth = mach_task_self();
+  
+  obstack_init (port_chain_obstack);
+
+  ret = mach_port_allocate (mach_task_self (), 
+			    MACH_PORT_RIGHT_RECEIVE,
+			    &thread_exception_port);
+  CHK ("Creating thread_exception_port for single stepping", ret);
+  
+  ret = mach_port_insert_right (mach_task_self (),
+				thread_exception_port,
+				thread_exception_port,
+				MACH_MSG_TYPE_MAKE_SEND);
+  CHK ("Inserting send right to thread_exception_port", ret);
+
+  /* Allocate message port */
+  ret = mach_port_allocate (mach_task_self (),
+			    MACH_PORT_RIGHT_RECEIVE,
+			    &our_message_port);
+  if (ret != KERN_SUCCESS)
+    warning ("Creating message port %s", mach_error_string (ret));
+  else
+    {
+      char buf[ MAX_NAME_LEN ];
+      ret = mach_port_move_member(mach_task_self (),
+				  our_message_port,
+				  inferior_wait_port_set);
+      if (ret != KERN_SUCCESS)
+	warning ("message move member %s", mach_error_string (ret));
+
+
+      /* @@@@ No way to change message port name currently */
+      /* Foo. This assumes gdb has a unix pid */
+      sprintf (buf, "gdb-%d", getpid ());
+      gdb_register_port (buf, our_message_port);
+    }
+  
+  /* Heap for thread commands */
+  obstack_init (cproc_obstack);
+
+  add_mach_specific_commands ();
+}