Get rid of ATTACH_NO_WAIT

[Pedro Alves <pedro at codesourcery dot com>]

As I described in the email I just sent, ATTACH_NO_WAIT being a host
macro, is wrong to be applied to other targets other than the
native target.  Due to it, the "target extended-remote; attach" sequence
behaves differently depending on the host.

This patch replaces the macro by a target property.

The only hosts that define it currently are Windows hosts,
and GNU Hurd.  I've tested the patch on
x86_64-unknown-linux-gnu {native/gdbserver}
and x86-pc-cygwin {native/gdbserver}.  I don't have access
to a Hurd system, but the change seems pretty obvious to me.

OK?

-- 
Pedro Alves

2008-06-28  Pedro Alves  <pedro@codesourcery.com>

	* config/i386/nm-cygwin.h (ATTACH_NO_WAIT): Delete.
	* config/i386/nm-i386gnu.h (ATTACH_NO_WAIT): Delete.

	* target.h (struct target_ops): Add to_attach_no_wait member.
	(target_attach_no_wait): New.
	* target.c (update_current_target): Inherit to_attach_no_wait.

	* infcmd.c: Replace ATTACH_NO_WAIT compile time check by
	target_attach_no_wait runtime check.

	* gnu-nat.c (init_gnu_ops): Set to_attach_no_wait in gnu_ops.
	* win32-nat.c (init_win32_ops): Set to_attach_no_wait in
	win32_ops.

---
 gdb/config/i386/nm-cygwin.h  |    1 
 gdb/config/i386/nm-i386gnu.h |    3 --
 gdb/gnu-nat.c                |    1 
 gdb/infcmd.c                 |   60 ++++++++++++++++++++++---------------------
 gdb/remote.c                 |    1 
 gdb/target.c                 |    1 
 gdb/target.h                 |    8 +++++
 gdb/win32-nat.c              |    1 
 8 files changed, 43 insertions(+), 33 deletions(-)

Index: src/gdb/config/i386/nm-cygwin.h
===================================================================
--- src.orig/gdb/config/i386/nm-cygwin.h
+++ src/gdb/config/i386/nm-cygwin.h
@@ -16,7 +16,6 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#define ATTACH_NO_WAIT
 #define ADD_SHARED_SYMBOL_FILES dll_symbol_command
 void dll_symbol_command (char *, int);
 
Index: src/gdb/config/i386/nm-i386gnu.h
===================================================================
--- src.orig/gdb/config/i386/nm-i386gnu.h
+++ src/gdb/config/i386/nm-i386gnu.h
@@ -26,9 +26,6 @@
 
 extern char *gnu_target_pid_to_str (int pid);
 
-/* Don't do wait_for_inferior on attach.  */
-#define ATTACH_NO_WAIT
-
 /* Thread flavors used in re-setting the T bit.  */
 #define THREAD_STATE_FLAVOR		i386_REGS_SEGS_STATE
 #define THREAD_STATE_SIZE		i386_THREAD_STATE_COUNT
Index: src/gdb/gnu-nat.c
===================================================================
--- src.orig/gdb/gnu-nat.c
+++ src/gdb/gnu-nat.c
@@ -2592,6 +2592,7 @@ init_gnu_ops (void)
   gnu_ops.to_doc = "GNU Hurd process";	/* to_doc */
   gnu_ops.to_open = gnu_open;		/* to_open */
   gnu_ops.to_attach = gnu_attach;	/* to_attach */
+  gnu_ops.to_attach_no_wait = 1;	/* to_attach_no_wait */
   gnu_ops.to_detach = gnu_detach;	/* to_detach */
   gnu_ops.to_resume = gnu_resume;	/* to_resume */
   gnu_ops.to_wait = gnu_wait;		/* to_wait */
Index: src/gdb/infcmd.c
===================================================================
--- src.orig/gdb/infcmd.c
+++ src/gdb/infcmd.c
@@ -2014,38 +2014,40 @@ attach_command (char *args, int from_tty
   init_wait_for_inferior ();
   clear_proceed_status ();
 
-  /* No traps are generated when attaching to inferior under Mach 3
-     or GNU hurd.  */
-#ifndef ATTACH_NO_WAIT
-  /* Careful here. See comments in inferior.h.  Basically some OSes
-     don't ignore SIGSTOPs on continue requests anymore.  We need a
-     way for handle_inferior_event to reset the stop_signal variable
-     after an attach, and this is what STOP_QUIETLY_NO_SIGSTOP is for.  */
-  stop_soon = STOP_QUIETLY_NO_SIGSTOP;
-
-  if (target_can_async_p ())
+  /* Some system don't generate traps when attaching to inferior.
+     E.g. Mach 3 or GNU hurd.  */
+  if (!target_attach_no_wait)
     {
-      /* sync_execution mode.  Wait for stop.  */
-      struct continuation_arg *arg1, *arg2, *arg3;
+      /* Careful here. See comments in inferior.h.  Basically some
+	 OSes don't ignore SIGSTOPs on continue requests anymore.  We
+	 need a way for handle_inferior_event to reset the stop_signal
+	 variable after an attach, and this is what
+	 STOP_QUIETLY_NO_SIGSTOP is for.  */
+      stop_soon = STOP_QUIETLY_NO_SIGSTOP;
 
-      arg1 =
-	(struct continuation_arg *) xmalloc (sizeof (struct continuation_arg));
-      arg2 =
-	(struct continuation_arg *) xmalloc (sizeof (struct continuation_arg));
-      arg3 =
-	(struct continuation_arg *) xmalloc (sizeof (struct continuation_arg));
-      arg1->next = arg2;
-      arg2->next = arg3;
-      arg3->next = NULL;
-      arg1->data.pointer = args;
-      arg2->data.integer = from_tty;
-      arg3->data.integer = async_exec;
-      add_continuation (attach_command_continuation, arg1);
-      return;
-    }
+      if (target_can_async_p ())
+	{
+	  /* sync_execution mode.  Wait for stop.  */
+	  struct continuation_arg *arg1, *arg2, *arg3;
 
-  wait_for_inferior (0);
-#endif
+	  arg1 =
+	    (struct continuation_arg *) xmalloc (sizeof (struct continuation_arg));
+	  arg2 =
+	    (struct continuation_arg *) xmalloc (sizeof (struct continuation_arg));
+	  arg3 =
+	    (struct continuation_arg *) xmalloc (sizeof (struct continuation_arg));
+	  arg1->next = arg2;
+	  arg2->next = arg3;
+	  arg3->next = NULL;
+	  arg1->data.pointer = args;
+	  arg2->data.integer = from_tty;
+	  arg3->data.integer = async_exec;
+	  add_continuation (attach_command_continuation, arg1);
+	  return;
+	}
+
+      wait_for_inferior (0);
+    }
 
   attach_command_post_wait (args, from_tty, async_exec);
 }
Index: src/gdb/target.h
===================================================================
--- src.orig/gdb/target.h
+++ src/gdb/target.h
@@ -407,6 +407,7 @@ struct target_ops
     int to_has_registers;
     int to_has_execution;
     int to_has_thread_control;	/* control thread execution */
+    int to_attach_no_wait;
     struct section_table
      *to_sections;
     struct section_table
@@ -559,6 +560,13 @@ void target_close (struct target_ops *ta
 #define	target_attach(args, from_tty)	\
      (*current_target.to_attach) (args, from_tty)
 
+/* Some targets don't generate traps when attaching to the inferior,
+   or their target_attach implementation takes care of the waiting.
+   These targets must set to_attach_no_wait.  */
+
+#define target_attach_no_wait \
+     (current_target.to_attach_no_wait)
+
 /* The target_attach operation places a process under debugger control,
    and stops the process.
 
Index: src/gdb/win32-nat.c
===================================================================
--- src.orig/gdb/win32-nat.c
+++ src/gdb/win32-nat.c
@@ -2080,6 +2080,7 @@ init_win32_ops (void)
   win32_ops.to_open = win32_open;
   win32_ops.to_close = win32_close;
   win32_ops.to_attach = win32_attach;
+  win32_ops.to_attach_no_wait = 1;
   win32_ops.to_detach = win32_detach;
   win32_ops.to_resume = win32_resume;
   win32_ops.to_wait = win32_wait;
Index: src/gdb/target.c
===================================================================
--- src.orig/gdb/target.c
+++ src/gdb/target.c
@@ -406,6 +406,7 @@ update_current_target (void)
       INHERIT (to_close, t);
       INHERIT (to_attach, t);
       INHERIT (to_post_attach, t);
+      INHERIT (to_attach_no_wait, t);
       INHERIT (to_detach, t);
       /* Do not inherit to_disconnect.  */
       INHERIT (to_resume, t);
Index: src/gdb/remote.c
===================================================================
--- src.orig/gdb/remote.c
+++ src/gdb/remote.c
@@ -7099,6 +7099,7 @@ Specify the serial device it is connecte
   extended_remote_ops.to_mourn_inferior = extended_remote_mourn;
   extended_remote_ops.to_detach = extended_remote_detach;
   extended_remote_ops.to_attach = extended_remote_attach;
+  extended_remote_ops.to_attach_no_wait = 0;
 }
 
 static int