[commit] Make to_follow_fork take a target argument

[Daniel Jacobowitz <drow at false dot org>]

A cleanup I've had in my tree for quite a while, that I posted as part
of my original target inheritance patch.

The GNU/Linux to_follow_fork method calls push_target
(&deprecated_child_ops).  This patch passes the correct target to
to_follow_fork, so that it can push the correct target instead.  The
fact that I needed to use push_target here still bugs me; that can
probably be fixed.  But this is the model we've been moving target
methods to anyway, so I don't feel that the patch is wasted even if I
eliminate the need later.

Tested on i686-pc-linux-gnu and committed.

-- 
Daniel Jacobowitz
CodeSourcery, LLC

2005-09-04  Daniel Jacobowitz  <dan@debian.org>

	* inf-child.c (inf_child_follow_fork): Add OPS argument.
	* inf-ptrace.c (inf_ptrace_follow_fork): Likewise.
	* inf-ttrace.c (inf_ttrace_follow_fork): Likewise.
	* inftarg.c (child_follow_fork): Likewise.
	* linux-nat.c (child_follow_fork): Likewise.  Use ops instead of
	&deprecated_child_ops.
	* target.c (update_current_target): Do not inherit to_follow_fork.
	(target_follow_fork): New function.
	(debug_to_follow_fork): Remove.
	(setup_target_debug): Don't set to_follow_fork.
	* target.h (struct target_ops): Add struct target_ops * to
	to_follow_fork.
	(child_follow_fork): Add struct target_ops * argument.
	(target_follow_fork): Replace macro with prototype.

Index: inf-child.c
===================================================================
RCS file: /cvs/src/src/gdb/inf-child.c,v
retrieving revision 1.6
diff -u -p -r1.6 inf-child.c
--- inf-child.c	11 Feb 2005 04:05:54 -0000	1.6
+++ inf-child.c	4 Sep 2005 16:01:43 -0000
@@ -2,7 +2,7 @@
    Unix.
 
    Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
-   1998, 1999, 2000, 2001, 2002, 2004 Free Software Foundation, Inc.
+   1998, 1999, 2000, 2001, 2002, 2004, 2005 Free Software Foundation, Inc.
 
    This file is part of GDB.
 
@@ -121,7 +121,7 @@ inf_child_remove_vfork_catchpoint (int p
 }
 
 static int
-inf_child_follow_fork (int follow_child)
+inf_child_follow_fork (struct target_ops *ops, int follow_child)
 {
   /* This version of Unix doesn't support following fork or vfork
      events.  */
Index: inf-ptrace.c
===================================================================
RCS file: /cvs/src/src/gdb/inf-ptrace.c,v
retrieving revision 1.24
diff -u -p -r1.24 inf-ptrace.c
--- inf-ptrace.c	13 Aug 2005 22:23:35 -0000	1.24
+++ inf-ptrace.c	4 Sep 2005 16:01:43 -0000
@@ -44,7 +44,7 @@ static struct target_ops *ptrace_ops_hac
 #ifdef PT_GET_PROCESS_STATE
 
 static int
-inf_ptrace_follow_fork (int follow_child)
+inf_ptrace_follow_fork (struct target_ops *ops, int follow_child)
 {
   pid_t pid, fpid;
   ptrace_state_t pe;
Index: inf-ttrace.c
===================================================================
RCS file: /cvs/src/src/gdb/inf-ttrace.c,v
retrieving revision 1.13
diff -u -p -r1.13 inf-ttrace.c
--- inf-ttrace.c	21 Jul 2005 10:36:19 -0000	1.13
+++ inf-ttrace.c	4 Sep 2005 16:01:43 -0000
@@ -404,7 +404,7 @@ inf_ttrace_stopped_by_watchpoint (void)
 static pid_t inf_ttrace_vfork_ppid = -1;
 
 static int
-inf_ttrace_follow_fork (int follow_child)
+inf_ttrace_follow_fork (struct target_ops *ops, int follow_child)
 {
   pid_t pid, fpid;
   lwpid_t lwpid, flwpid;
Index: inftarg.c
===================================================================
RCS file: /cvs/src/src/gdb/inftarg.c,v
retrieving revision 1.42
diff -u -p -r1.42 inftarg.c
--- inftarg.c	23 May 2005 19:32:27 -0000	1.42
+++ inftarg.c	4 Sep 2005 16:01:43 -0000
@@ -1,7 +1,7 @@
 /* Target-vector operations for controlling Unix child processes, for GDB.
 
    Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999,
-   2000, 2002, 2003, 2004 Free Software Foundation, Inc.
+   2000, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
 
    Contributed by Cygnus Support.
 
@@ -401,7 +401,7 @@ child_remove_vfork_catchpoint (int pid)
 
 #if !defined(CHILD_FOLLOW_FORK)
 int
-child_follow_fork (int follow_child)
+child_follow_fork (struct target_ops *ops, int follow_child)
 {
   /* This version of Unix doesn't support following fork or vfork events.  */
   return 0;
Index: linux-nat.c
===================================================================
RCS file: /cvs/src/src/gdb/linux-nat.c,v
retrieving revision 1.31
diff -u -p -r1.31 linux-nat.c
--- linux-nat.c	9 Aug 2005 16:35:45 -0000	1.31
+++ linux-nat.c	4 Sep 2005 16:01:44 -0000
@@ -334,7 +334,7 @@ child_post_startup_inferior (ptid_t ptid
 #endif
 
 int
-child_follow_fork (int follow_child)
+child_follow_fork (struct target_ops *ops, int follow_child)
 {
   ptid_t last_ptid;
   struct target_waitstatus last_status;
@@ -466,7 +466,10 @@ child_follow_fork (int follow_child)
 	target_detach (NULL, 0);
 
       inferior_ptid = pid_to_ptid (child_pid);
-      push_target (&deprecated_child_ops);
+
+      /* Reinstall ourselves, since we might have been removed in
+	 target_detach (which does other necessary cleanup).  */
+      push_target (ops);
 
       /* Reset breakpoints in the child as appropriate.  */
       follow_inferior_reset_breakpoints ();
Index: target.c
===================================================================
RCS file: /cvs/src/src/gdb/target.c,v
retrieving revision 1.110
diff -u -p -r1.110 target.c
--- target.c	18 Jul 2005 21:00:49 -0000	1.110
+++ target.c	4 Sep 2005 16:01:44 -0000
@@ -422,7 +422,7 @@ update_current_target (void)
       INHERIT (to_remove_fork_catchpoint, t);
       INHERIT (to_insert_vfork_catchpoint, t);
       INHERIT (to_remove_vfork_catchpoint, t);
-      INHERIT (to_follow_fork, t);
+      /* Do not inherit to_follow_fork.  */
       INHERIT (to_insert_exec_catchpoint, t);
       INHERIT (to_remove_exec_catchpoint, t);
       INHERIT (to_reported_exec_events_per_exec_call, t);
@@ -579,9 +579,6 @@ update_current_target (void)
   de_fault (to_remove_vfork_catchpoint, 
 	    (int (*) (int)) 
 	    tcomplain);
-  de_fault (to_follow_fork,
-	    (int (*) (int)) 
-	    target_ignore);
   de_fault (to_insert_exec_catchpoint, 
 	    (void (*) (int)) 
 	    tcomplain);
@@ -1501,6 +1498,31 @@ target_async_mask (int mask)
 }
 
 /* Look through the list of possible targets for a target that can
+   follow forks.  */
+
+int
+target_follow_fork (int follow_child)
+{
+  struct target_ops *t;
+
+  for (t = current_target.beneath; t != NULL; t = t->beneath)
+    {
+      if (t->to_follow_fork != NULL)
+	{
+	  int retval = t->to_follow_fork (t, follow_child);
+	  if (targetdebug)
+	    fprintf_unfiltered (gdb_stdlog, "target_follow_fork (%d) = %d\n",
+				follow_child, retval);
+	  return retval;
+	}
+    }
+
+  /* Some target returned a fork event, but did not know how to follow it.  */
+  internal_error (__FILE__, __LINE__,
+		  "could not find a target to follow fork");
+}
+
+/* Look through the list of possible targets for a target that can
    execute a run or attach command without any other data.  This is
    used to locate the default process stratum.
 
@@ -2336,17 +2358,6 @@ debug_to_remove_vfork_catchpoint (int pi
   return retval;
 }
 
-static int
-debug_to_follow_fork (int follow_child)
-{
-  int retval =  debug_target.to_follow_fork (follow_child);
-
-  fprintf_unfiltered (gdb_stdlog, "target_follow_fork (%d) = %d\n",
-		      follow_child, retval);
-
-  return retval;
-}
-
 static void
 debug_to_insert_exec_catchpoint (int pid)
 {
@@ -2539,7 +2550,6 @@ setup_target_debug (void)
   current_target.to_remove_fork_catchpoint = debug_to_remove_fork_catchpoint;
   current_target.to_insert_vfork_catchpoint = debug_to_insert_vfork_catchpoint;
   current_target.to_remove_vfork_catchpoint = debug_to_remove_vfork_catchpoint;
-  current_target.to_follow_fork = debug_to_follow_fork;
   current_target.to_insert_exec_catchpoint = debug_to_insert_exec_catchpoint;
   current_target.to_remove_exec_catchpoint = debug_to_remove_exec_catchpoint;
   current_target.to_reported_exec_events_per_exec_call = debug_to_reported_exec_events_per_exec_call;
Index: target.h
===================================================================
RCS file: /cvs/src/src/gdb/target.h,v
retrieving revision 1.75
diff -u -p -r1.75 target.h
--- target.h	26 May 2005 20:48:58 -0000	1.75
+++ target.h	4 Sep 2005 16:01:44 -0000
@@ -1,7 +1,7 @@
 /* Interface between GDB and target environments, including files and processes
 
    Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-   1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
+   1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
 
    Contributed by Cygnus Support.  Written by John Gilmore.
 
@@ -362,7 +362,7 @@ struct target_ops
     int (*to_remove_fork_catchpoint) (int);
     void (*to_insert_vfork_catchpoint) (int);
     int (*to_remove_vfork_catchpoint) (int);
-    int (*to_follow_fork) (int);
+    int (*to_follow_fork) (struct target_ops *, int);
     void (*to_insert_exec_catchpoint) (int);
     int (*to_remove_exec_catchpoint) (int);
     int (*to_reported_exec_events_per_exec_call) (void);
@@ -582,7 +582,7 @@ extern int child_remove_vfork_catchpoint
 
 extern void child_acknowledge_created_inferior (int);
 
-extern int child_follow_fork (int);
+extern int child_follow_fork (struct target_ops *, int);
 
 extern void child_insert_exec_catchpoint (int);
 
@@ -747,8 +747,7 @@ extern void target_load (char *arg, int 
    This function returns 1 if the inferior should not be resumed
    (i.e. there is another event pending).  */
 
-#define target_follow_fork(follow_child) \
-     (*current_target.to_follow_fork) (follow_child)
+int target_follow_fork (int follow_child);
 
 /* On some targets, we can catch an inferior exec event when it
    occurs.  These functions insert/remove an already-created