Re: [RFC] remote-mips.c: Fix bit rot associated with the inferior's state

[Kevin Buettner <kevinb@redhat.com>]

Below is a slight revision over yesterday's patch.   The only difference
between this patch and the previous one is the addition of the change to
mips_error().  That change avoids an internal error when inferior_ptid
is the same as null_ptid.

I'll wait a few more days for comments before checking this in.

Kevin

	* remote-mips.c (gdbthread.h): Include.
	(mips_error): Only mourn the inferior when inferior_ptid is non-null.
	(magic_null_ptid): Declare.
	(common_open): Set inferior_ptid, add it as an inferior, and
	as a thread too.  Set up the inferior's address spaces.
	(mips_kill): Make sure that target_mourn_inferior is invoked.
	(mips_load): Don't null out inferior_ptid.
	(_initialize_remote_mips): Initialize magic_null_ptid.

Index: remote-mips.c
===================================================================
RCS file: /cvs/src/src/gdb/remote-mips.c,v
retrieving revision 1.108
diff -u -p -r1.108 remote-mips.c
--- remote-mips.c	26 Feb 2010 23:11:24 -0000	1.108
+++ remote-mips.c	2 Mar 2010 23:02:32 -0000
@@ -35,6 +35,7 @@
 #include "regcache.h"
 #include <ctype.h>
 #include "mips-tdep.h"
+#include "gdbthread.h"
 \f
 
 /* Breakpoint types.  Values 0, 1, and 2 must agree with the watch
@@ -483,7 +484,8 @@ mips_error (char *string,...)
   close_ports ();
 
   printf_unfiltered ("Ending remote MIPS debugging.\n");
-  target_mourn_inferior ();
+  if (!ptid_equal (inferior_ptid, null_ptid))
+    target_mourn_inferior ();
 
   deprecated_throw_reason (RETURN_ERROR);
 }
@@ -1457,6 +1459,8 @@ mips_initialize (void)
   mips_request ('r', 0, 0, &err, mips_receive_wait, NULL);
 }
 
+static ptid_t magic_null_ptid;
+
 /* Open a connection to the remote board.  */
 static void
 common_open (struct target_ops *ops, char *name, int from_tty,
@@ -1468,6 +1472,7 @@ common_open (struct target_ops *ops, cha
   char *remote_name = 0;
   char *local_name = 0;
   char **argv;
+  struct inferior *inf;
 
   if (name == 0)
     error (
@@ -1563,6 +1568,12 @@ device is attached to the target board (
   /* Switch to using remote target now.  */
   push_target (ops);
 
+  inferior_ptid = magic_null_ptid;
+  inf = add_inferior_silent (ptid_get_pid (inferior_ptid));
+  inf->aspace = current_program_space->aspace;
+  inf->pspace = current_program_space;
+  add_thread_silent (inferior_ptid);
+
   /* FIXME: Should we call start_remote here?  */
 
   /* Try to figure out the processor model if possible.  */
@@ -2140,7 +2151,10 @@ static void
 mips_kill (struct target_ops *ops)
 {
   if (!mips_wait_flag)
-    return;
+    {
+      target_mourn_inferior ();
+      return;
+    }
 
   interrupt_count++;
 
@@ -2173,6 +2187,8 @@ Give up (and stop debugging it)? ")))
 
   serial_send_break (mips_desc);
 
+  target_mourn_inferior ();
+
 #if 0
   if (mips_is_open)
     {
@@ -3297,8 +3313,6 @@ mips_load (char *file, int from_tty)
   if (exec_bfd)
     regcache_write_pc (regcache, bfd_get_start_address (exec_bfd));
 
-  inferior_ptid = null_ptid;	/* No process now */
-
 /* This is necessary because many things were based on the PC at the time that
    we attached to the monitor, which is no longer valid now that we have loaded
    new code (and just changed the PC).  Another way to do this might be to call
@@ -3458,4 +3472,5 @@ Use \"on\" to enable the masking and \"o
 			   NULL,
 			   NULL, /* FIXME: i18n: */
 			   &setlist, &showlist);
+  magic_null_ptid = ptid_build (42000, 1, -1);
 }