gdb/

2009-07-02  Pedro Alves  <pedro@codesourcery.com>

	* linux-nat.c (linux_child_follow_fork): If we're staying attached
	to the child process, enable event reporting on it.  Don't handle
	checkpoints here.  Instead, add the child fork to the lwp thread
	and inferior lists without clobbering the previous inferior.  Let
	the thread_db layer learn about a new child process, even if
	following the parent.
	(linux_nat_switch_fork): Delete lwps of the current inferior only,
	instead of clearing the whole list.  Use thread_change_ptid to
	give the core the illusion the new checkpoint is still the same
	inferior.  Clear the register cache.
	(linux_handle_extended_wait): Handle checkpoints here.
	(linux_multi_process): Turn on.
	* linux-fork.c (struct fork_info) <pc>: Remove field.
	(init_fork_list): Do not delete the checkpoint from the inferior
	list (it is not there).
	(fork_load_infrun_state): Don't switch inferior_ptid here.  Pass
	the new checkpoint's ptid to linux_nat_switch_fork.
	(fork_save_infrun_state): Make static.  Don't stop the pc field of
	fork_info, it's gone.
	(linux_fork_mourn_inferior): Don't delete the checkpoint from the
	inferior list, it's not there.
	(linux_fork_detach): Ditto.
	(delete_fork_command): Replace mention of fork/checkpoint by
	checkpoint only.
	(detach_fork_command): Likewise.  Don't delete the checkpoint from
	the inferior list.
	(info_forks_command): Adjust.
	(restore_detach_fork): Delete.
	(checkpointing_pid): New.
	(linux_fork_checkpointing_p): New.
	(save_detach_fork): Delete.
	(checkpoint_command): Delete temp_detach_fork.  Don't remove
	breakpoints, that's a nop.  Store the pid of the process we're
	checkpointing, and use make_cleanup_restore_integer to restore it.
	Don't reinsert breakpoints here.
	(process_command, fork_command): Delete.
	(restart_command): Update comments to only mention checkpoints,
	not forks.
	(_initialize_linux_fork): Delete "fork", "process", "info forks"
	commands.
	* linux-fork.h (fork_save_infrun_state, fork_list): Delete
	declarations.
	(linux_fork_checkpointing_p): Declare.
	* cli/cli-cmds.c (killlist): New.
	* cli/cli-cmds.h (killlist): Declare.
	* gdbcmd.h (killlist): Declare.
	* inferior.c: Include "gdbthread.h".
	(detach_inferior_command, kill_inferior_command)
	(inferior_command): New.
	(info_inferiors_command): Allow specifying a specific inferior id.
	(_initialize_inferiors): Register "inferior", "kill inferior" and
	"detach inferior" commands.
	* infcmd.c (_initialize_infcmd): Make "kill" a prefix command.
	* gdbthread.h (any_thread_of_process): Declare.
	* thread.c (any_thread_of_process): New.

	* NEWS: Mention multi-inferior debugging.  Mention 'info
	inferiors', 'inferior', 'detach inferior' and 'kill inferior' as
	new commands.
	(Removed commands): New section, mentioning that 'info forks',
	'fork', 'process', 'delete fork' and 'detach fork' are now gone.

gdb/testsuite/
2009-07-02  Pedro Alves  <pedro@codesourcery.com>

	* gdb.base/multi-forks.exp: Only run detach-on-fork tests on
	linux.  Adjust to use "inferior", "info inferiors", "detach
	inferior" and "kill inferior" instead of "restart", "info fork",
	"detach fork" and "delete fork".
	* gdb.base/ending-run.exp: Spell out "info".
	* gdb.base/help.exp: Adjust to use test_prefix_command_help for
	the "kill" command.

gdb/doc/
2009-07-02  Pedro Alves  <pedro@codesourcery.com>

	* gdb.texinfo (Debugging multiple inferiors): Document the
	"inferior", "detach inferior" and "kill inferior" commands.
	(Debugging Programs with Multiple Processes): Adjust to mention
	generic "inferior" commands.  Delete mention of "detach fork" and
	"delete fork".  Cross reference to "Debugging multiple inferiors"
	section.

1 files changed, 85 insertions, 30 deletions

diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c
index 0253fe9..f8d7a5c 100644
--- a/gdb/linux-nat.c
+++ b/gdb/linux-nat.c
@@ -338,6 +338,12 @@ static int stop_callback (struct lwp_info *lp, void *data);
 
 static void block_child_signals (sigset_t *prev_mask);
 static void restore_child_signals_mask (sigset_t *prev_mask);
+
+struct lwp_info;
+static struct lwp_info *add_lwp (ptid_t ptid);
+static void purge_lwp_list (int pid);
+static struct lwp_info *find_lwp_pid (ptid_t ptid);
+
 
 /* Trivial list manipulation functions to keep track of a list of
    new stopped processes.  */
@@ -587,6 +593,9 @@ linux_child_follow_fork (struct target_ops *ops, int follow_child)
     parent_pid = ptid_get_pid (inferior_ptid);
   child_pid = PIDGET (inferior_thread ()->pending_follow.value.related_pid);
 
+  if (!detach_fork)
+    linux_enable_event_reporting (pid_to_ptid (child_pid));
+
   if (! follow_child)
     {
       /* We're already attached to the parent, by default. */
@@ -617,8 +626,9 @@ linux_child_follow_fork (struct target_ops *ops, int follow_child)
 	}
       else
 	{
-	  struct fork_info *fp;
 	  struct inferior *parent_inf, *child_inf;
+	  struct lwp_info *lp;
+	  struct cleanup *old_chain;
 
 	  /* Add process to GDB's tables.  */
 	  child_inf = add_inferior (child_pid);
@@ -627,11 +637,16 @@ linux_child_follow_fork (struct target_ops *ops, int follow_child)
 	  child_inf->attach_flag = parent_inf->attach_flag;
 	  copy_terminal_info (child_inf, parent_inf);
 
-	  /* Retain child fork in ptrace (stopped) state.  */
-	  fp = find_fork_pid (child_pid);
-	  if (!fp)
-	    fp = add_fork (child_pid);
-	  fork_save_infrun_state (fp, 0);
+	  old_chain = save_inferior_ptid ();
+
+	  inferior_ptid = ptid_build (child_pid, child_pid, 0);
+	  add_thread (inferior_ptid);
+	  lp = add_lwp (inferior_ptid);
+	  lp->stopped = 1;
+
+	  check_for_thread_db ();
+
+	  do_cleanups (old_chain);
 	}
 
       if (has_vforked)
@@ -692,6 +707,7 @@ linux_child_follow_fork (struct target_ops *ops, int follow_child)
     {
       struct thread_info *tp;
       struct inferior *parent_inf, *child_inf;
+      struct lwp_info *lp;
 
       /* Before detaching from the parent, remove all breakpoints from it. */
       remove_breakpoints ();
@@ -733,30 +749,33 @@ linux_child_follow_fork (struct target_ops *ops, int follow_child)
 
       if (has_vforked)
 	{
+	  struct lwp_info *parent_lwp;
+
 	  linux_parent_pid = parent_pid;
+
+	  /* Get rid of the inferior on the core side as well.  */
+	  inferior_ptid = null_ptid;
 	  detach_inferior (parent_pid);
-	}
-      else if (!detach_fork)
-	{
-	  struct fork_info *fp;
-	  /* Retain parent fork in ptrace (stopped) state.  */
-	  fp = find_fork_pid (parent_pid);
-	  if (!fp)
-	    fp = add_fork (parent_pid);
-	  fork_save_infrun_state (fp, 0);
 
-	  /* Also add an entry for the child fork.  */
-	  fp = find_fork_pid (child_pid);
-	  if (!fp)
-	    fp = add_fork (child_pid);
-	  fork_save_infrun_state (fp, 0);
+	  /* Also get rid of all its lwps.  We will detach from this
+	     inferior soon-ish, but, we will still get an exit event
+	     reported through waitpid when it exits.  If we didn't get
+	     rid of the lwps from our list, we would end up reporting
+	     the inferior exit to the core, which would then try to
+	     mourn a non-existing (from the core's perspective)
+	     inferior.  */
+	  parent_lwp = find_lwp_pid (pid_to_ptid (parent_pid));
+	  purge_lwp_list (GET_PID (parent_lwp->ptid));
+	  linux_parent_pid = parent_pid;
 	}
-      else
+      else if (detach_fork)
 	target_detach (NULL, 0);
 
       inferior_ptid = ptid_build (child_pid, child_pid, 0);
+      add_thread (inferior_ptid);
+      lp = add_lwp (inferior_ptid);
+      lp->stopped = 1;
 
-      linux_nat_switch_fork (inferior_ptid);
       check_for_thread_db ();
     }
 
@@ -1073,22 +1092,30 @@ iterate_over_lwps (ptid_t filter,
   return NULL;
 }
 
-/* Update our internal state when changing from one fork (checkpoint,
-   et cetera) to another indicated by NEW_PTID.  We can only switch
-   single-threaded applications, so we only create one new LWP, and
-   the previous list is discarded.  */
+/* Update our internal state when changing from one checkpoint to
+   another indicated by NEW_PTID.  We can only switch single-threaded
+   applications, so we only create one new LWP, and the previous list
+   is discarded.  */
 
 void
 linux_nat_switch_fork (ptid_t new_ptid)
 {
   struct lwp_info *lp;
 
-  init_lwp_list ();
+  purge_lwp_list (GET_PID (inferior_ptid));
+
   lp = add_lwp (new_ptid);
   lp->stopped = 1;
 
-  init_thread_list ();
-  add_thread_silent (new_ptid);
+  /* This changes the thread's ptid while preserving the gdb thread
+     num.  Also changes the inferior pid, while preserving the
+     inferior num.  */
+  thread_change_ptid (inferior_ptid, new_ptid);
+
+  /* We've just told GDB core that the thread changed target id, but,
+     in fact, it really is a different thread, with different register
+     contents.  */
+  registers_changed ();
 }
 
 /* Handle the exit of a single thread LP.  */
@@ -1815,6 +1842,34 @@ linux_handle_extended_wait (struct lwp_info *lp, int status,
 
       ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
 
+      if (event == PTRACE_EVENT_FORK
+	  && linux_fork_checkpointing_p (GET_PID (lp->ptid)))
+	{
+	  struct fork_info *fp;
+
+	  /* Handle checkpointing by linux-fork.c here as a special
+	     case.  We don't want the follow-fork-mode or 'catch fork'
+	     to interfere with this.  */
+
+	  /* This won't actually modify the breakpoint list, but will
+	     physically remove the breakpoints from the child.  */
+	  detach_breakpoints (new_pid);
+
+	  /* Retain child fork in ptrace (stopped) state.  */
+	  fp = find_fork_pid (new_pid);
+	  if (!fp)
+	    fp = add_fork (new_pid);
+
+	  /* Report as spurious, so that infrun doesn't want to follow
+	     this fork.  We're actually doing an infcall in
+	     linux-fork.c.  */
+	  ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
+	  linux_enable_event_reporting (pid_to_ptid (new_pid));
+
+	  /* Report the stop to the core.  */
+	  return 0;
+	}
+
       if (event == PTRACE_EVENT_FORK)
 	ourstatus->kind = TARGET_WAITKIND_FORKED;
       else if (event == PTRACE_EVENT_VFORK)
@@ -4295,7 +4350,7 @@ linux_nat_supports_non_stop (void)
 /* True if we want to support multi-process.  To be removed when GDB
    supports multi-exec.  */
 
-int linux_multi_process = 0;
+int linux_multi_process = 1;
 
 static int
 linux_nat_supports_multi_process (void)