infrun.c: add for_each_just_stopped_thread

This is a preparatory/cleanup patch that does two things:

- Renames 'delete_step_thread_step_resume_breakpoint'.  The
  "step_resume" part is misnomer these days, as the function deletes
  other kinds of breakpoints, not just the step-resume breakpoint.  A
  following patch will want to make it delete yet another kind of
  breakpoint, even.

- Splits out the logic of which threads get those breakpoints deleted
  to a separate "for_each"-style function, so that the same following
  patch may use it with a different callback.

Tested on x86_64 Fedora 20.

gdb/
2014-10-15  Pedro Alves  <palves@redhat.com>

	* infrun.c (delete_step_resume_breakpoint_callback): Delete.
	(delete_thread_infrun_breakpoints): New function, with parts
	salvaged from delete_step_resume_breakpoint_callback.
	(delete_step_thread_step_resume_breakpoint): Delete.
	(for_each_just_stopped_thread_callback_func): New typedef.
	(for_each_just_stopped_thread): New function.
	(delete_just_stopped_threads_infrun_breakpoints): New function.
	(delete_step_thread_step_resume_breakpoint_cleanup): Rename to ...
	(delete_just_stopped_threads_infrun_breakpoints_cleanup):
	... this.  Adjust.
	(wait_for_inferior, fetch_inferior_event): Adjust to renames.

2 files changed, 54 insertions, 32 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 0b03948..ef803bb 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,19 @@
 2014-10-15  Pedro Alves  <palves@redhat.com>
 
+	* infrun.c (delete_step_resume_breakpoint_callback): Delete.
+	(delete_thread_infrun_breakpoints): New function, with parts
+	salvaged from delete_step_resume_breakpoint_callback.
+	(delete_step_thread_step_resume_breakpoint): Delete.
+	(for_each_just_stopped_thread_callback_func): New typedef.
+	(for_each_just_stopped_thread): New function.
+	(delete_just_stopped_threads_infrun_breakpoints): New function.
+	(delete_step_thread_step_resume_breakpoint_cleanup): Rename to ...
+	(delete_just_stopped_threads_infrun_breakpoints_cleanup):
+	... this.  Adjust.
+	(wait_for_inferior, fetch_inferior_event): Adjust to renames.
+
+2014-10-15  Pedro Alves  <palves@redhat.com>
+
 	* breakpoint.c (should_be_inserted): Don't insert watchpoints if
 	trying to step past a non-steppable watchpoint.
 	* gdbthread.h (struct thread_info) <stepping_over_watchpoint>: New
diff --git a/gdb/infrun.c b/gdb/infrun.c
index d0431df..aa36dbc 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -2846,54 +2846,61 @@ infrun_thread_thread_exit (struct thread_info *tp, int silent)
     nullify_last_target_wait_ptid ();
 }
 
-/* Callback for iterate_over_threads.  */
+/* Delete the step resume, single-step and longjmp/exception resume
+   breakpoints of TP.  */
 
-static int
-delete_step_resume_breakpoint_callback (struct thread_info *info, void *data)
+static void
+delete_thread_infrun_breakpoints (struct thread_info *tp)
 {
-  if (is_exited (info->ptid))
-    return 0;
-
-  delete_step_resume_breakpoint (info);
-  delete_exception_resume_breakpoint (info);
-  return 0;
+  delete_step_resume_breakpoint (tp);
+  delete_exception_resume_breakpoint (tp);
 }
 
-/* In all-stop, delete the step resume breakpoint of any thread that
-   had one.  In non-stop, delete the step resume breakpoint of the
-   thread that just stopped.  */
+/* If the target still has execution, call FUNC for each thread that
+   just stopped.  In all-stop, that's all the non-exited threads; in
+   non-stop, that's the current thread, only.  */
+
+typedef void (*for_each_just_stopped_thread_callback_func)
+  (struct thread_info *tp);
 
 static void
-delete_step_thread_step_resume_breakpoint (void)
+for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
 {
-  if (!target_has_execution
-      || ptid_equal (inferior_ptid, null_ptid))
-    /* If the inferior has exited, we have already deleted the step
-       resume breakpoints out of GDB's lists.  */
+  if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
     return;
 
   if (non_stop)
     {
-      /* If in non-stop mode, only delete the step-resume or
-	 longjmp-resume breakpoint of the thread that just stopped
-	 stepping.  */
-      struct thread_info *tp = inferior_thread ();
-
-      delete_step_resume_breakpoint (tp);
-      delete_exception_resume_breakpoint (tp);
+      /* If in non-stop mode, only the current thread stopped.  */
+      func (inferior_thread ());
     }
   else
-    /* In all-stop mode, delete all step-resume and longjmp-resume
-       breakpoints of any thread that had them.  */
-    iterate_over_threads (delete_step_resume_breakpoint_callback, NULL);
+    {
+      struct thread_info *tp;
+
+      /* In all-stop mode, all threads have stopped.  */
+      ALL_NON_EXITED_THREADS (tp)
+        {
+	  func (tp);
+	}
+    }
+}
+
+/* Delete the step resume and longjmp/exception resume breakpoints of
+   the threads that just stopped.  */
+
+static void
+delete_just_stopped_threads_infrun_breakpoints (void)
+{
+  for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
 }
 
 /* A cleanup wrapper.  */
 
 static void
-delete_step_thread_step_resume_breakpoint_cleanup (void *arg)
+delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
 {
-  delete_step_thread_step_resume_breakpoint ();
+  delete_just_stopped_threads_infrun_breakpoints ();
 }
 
 /* Pretty print the results of target_wait, for debugging purposes.  */
@@ -3028,8 +3035,9 @@ wait_for_inferior (void)
     fprintf_unfiltered
       (gdb_stdlog, "infrun: wait_for_inferior ()\n");
 
-  old_cleanups =
-    make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup, NULL);
+  old_cleanups
+    = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
+		    NULL);
 
   while (1)
     {
@@ -3151,7 +3159,7 @@ fetch_inferior_event (void *client_data)
     {
       struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
 
-      delete_step_thread_step_resume_breakpoint ();
+      delete_just_stopped_threads_infrun_breakpoints ();
 
       /* We may not find an inferior if this was a process exit.  */
       if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)