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

Kevin Buettner
2010-03-02T00:25:57Z

The patch below updates remote-mips.c so inferior_ptid is set after
successfully connecting to a target board. A suitable inferior
and thread are also created at that time. I was surprised to find
that I also needed to fiddle with the inferior's aspace and pspace.

Calls to target_mourn_inferior() have also been added.

Using this patch in conjunction with some other soon-to-be-submitted
patches allows me to connect to a board and debug a program on the
board.

Comments?

* remote-mips.c (gdbthread.h): Include.
(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 00:17:56 -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
@@ -1457,6 +1458,8 @@ 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 +1471,7 @@ 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 +1567,12 @@ 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 +2150,10 @@ static void
mips_kill (struct target_ops *ops)
{
if (!mips_wait_flag)
- return;
+ {
+ target_mourn_inferior ();
+ return;
+ }

interrupt_count++;

@@ -2173,6 +2186,8 @@ Give up (and stop debugging it)? ")))

serial_send_break (mips_desc);

+ target_mourn_inferior ();
+
#if 0
if (mips_is_open)
{
@@ -3297,8 +3312,6 @@ 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 +3471,5 @@ Use \"on\" to enable the masking and \"o
NULL,
NULL, /* FIXME: i18n: */
&setlist, &showlist);
+ magic_null_ptid = ptid_build (42000, 1, -1);
}