gdb, infrun: refactor part of `proceed` into separate function

Split the thread resuming code from proceed into new function
proceed_resume_thread_checked.

Co-Authored-By: Christina Schimpe <christina.schimpe@intel.com>

diff --git a/gdb/infrun.c b/gdb/infrun.c
index 5b0257076f02deb6e8c469926ffb0c4ea803b728..010fcd7952f280553f7b096a6ee0f429d80b6cdf 100644 (file)
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -3268,6 +3268,89 @@ check_multi_target_resumption (process_stratum_target *resume_target)
     }
 }
 
+/* Helper function for `proceed`.  Check if thread TP is suitable for
+   resuming, and, if it is, switch to the thread and call
+   `keep_going_pass_signal`.  If TP is not suitable for resuming then this
+   function will just return without switching threads.  */
+
+static void
+proceed_resume_thread_checked (thread_info *tp)
+{
+  if (!tp->inf->has_execution ())
+    {
+      infrun_debug_printf ("[%s] target has no execution",
+                          tp->ptid.to_string ().c_str ());
+      return;
+    }
+
+  if (tp->resumed ())
+    {
+      infrun_debug_printf ("[%s] resumed",
+                          tp->ptid.to_string ().c_str ());
+      gdb_assert (tp->executing () || tp->has_pending_waitstatus ());
+      return;
+    }
+
+  if (thread_is_in_step_over_chain (tp))
+    {
+      infrun_debug_printf ("[%s] needs step-over",
+                          tp->ptid.to_string ().c_str ());
+      return;
+    }
+
+  /* When handling a vfork GDB removes all breakpoints from the program
+     space in which the vfork is being handled, as such we must take care
+     not to resume any thread other than the vfork parent -- resuming the
+     vfork parent allows GDB to receive and handle the 'vfork done'
+     event.  */
+  if (tp->inf->thread_waiting_for_vfork_done != nullptr)
+    {
+      if (target_is_non_stop_p ())
+       {
+         /* For non-stop targets, regardless of whether GDB is using
+            all-stop or non-stop mode, threads are controlled
+            individually.
+
+            When a thread is handling a vfork, breakpoints are removed
+            from the inferior (well, program space in fact), so it is
+            critical that we don't try to resume any thread other than the
+            vfork parent.  */
+         if (tp != tp->inf->thread_waiting_for_vfork_done)
+           {
+             infrun_debug_printf ("[%s] thread %s of this inferior is "
+                                  "waiting for vfork-done",
+                                  tp->ptid.to_string ().c_str (),
+                                  tp->inf->thread_waiting_for_vfork_done
+                                    ->ptid.to_string ().c_str ());
+             return;
+           }
+       }
+      else
+       {
+         /* For all-stop targets, when we attempt to resume the inferior,
+            we will only resume the vfork parent thread, this is handled
+            in internal_resume_ptid.
+
+            Additionally, we will always be called with the vfork parent
+            thread as the current thread (TP) thanks to follow_fork, as
+            such the following assertion should hold.
+
+            Beyond this there is nothing more that needs to be done
+            here.  */
+         gdb_assert (tp == tp->inf->thread_waiting_for_vfork_done);
+       }
+    }
+
+  infrun_debug_printf ("resuming %s",
+                      tp->ptid.to_string ().c_str ());
+
+  execution_control_state ecs (tp);
+  switch_to_thread (tp);
+  keep_going_pass_signal (&ecs);
+  if (!ecs.wait_some_more)
+    error (_("Command aborted."));
+}
+
 /* Basic routine for continuing the program in various fashions.
 
    ADDR is the address to resume at, or -1 for resume where stopped.
@@ -3456,77 +3539,11 @@ proceed (CORE_ADDR addr, enum gdb_signal siggnal)
                                                       resume_ptid))
          {
            switch_to_thread_no_regs (tp);
-
-           if (!tp->inf->has_execution ())
-             {
-               infrun_debug_printf ("[%s] target has no execution",
-                                    tp->ptid.to_string ().c_str ());
-               continue;
-             }
-
-           if (tp->resumed ())
-             {
-               infrun_debug_printf ("[%s] resumed",
-                                    tp->ptid.to_string ().c_str ());
-               gdb_assert (tp->executing () || tp->has_pending_waitstatus ());
-               continue;
-             }
-
-           if (thread_is_in_step_over_chain (tp))
-             {
-               infrun_debug_printf ("[%s] needs step-over",
-                                    tp->ptid.to_string ().c_str ());
-               continue;
-             }
-
-           /* If a thread of that inferior is waiting for a vfork-done
-              (for a detached vfork child to exec or exit), breakpoints are
-              removed.  We must not resume any thread of that inferior, other
-              than the one waiting for the vfork-done.  */
-           if (tp->inf->thread_waiting_for_vfork_done != nullptr
-               && tp != tp->inf->thread_waiting_for_vfork_done)
-             {
-               infrun_debug_printf ("[%s] another thread of this inferior is "
-                                    "waiting for vfork-done",
-                                    tp->ptid.to_string ().c_str ());
-               continue;
-             }
-
-           infrun_debug_printf ("resuming %s",
-                                tp->ptid.to_string ().c_str ());
-
-           execution_control_state ecs (tp);
-           switch_to_thread (tp);
-           keep_going_pass_signal (&ecs);
-           if (!ecs.wait_some_more)
-             error (_("Command aborted."));
-         }
-      }
-    else if (!cur_thr->resumed ()
-            && !thread_is_in_step_over_chain (cur_thr))
-      {
-       /* In non-stop mode, if a there exists a thread waiting for a vfork
-          then only allow that thread to resume (breakpoints are removed
-          from an inferior when handling a vfork).
-
-          We check target_is_non_stop_p here rather than just checking the
-          non-stop flag, though these are equivalent (all-stop on a
-          non-stop target was handled in a previous block, so at this
-          point, if target_is_non_stop_p then GDB must be running on
-          non-stop mode).  By using target_is_non_stop_p it will be easier
-          to merge this block with the previous in a later commit.  */
-       if (!(target_is_non_stop_p ()
-             && cur_thr->inf->thread_waiting_for_vfork_done != nullptr
-             && cur_thr->inf->thread_waiting_for_vfork_done != cur_thr))
-         {
-           /* The thread wasn't started, and isn't queued, run it now.  */
-           execution_control_state ecs (cur_thr);
-           switch_to_thread (cur_thr);
-           keep_going_pass_signal (&ecs);
-           if (!ecs.wait_some_more)
-             error (_("Command aborted."));
+           proceed_resume_thread_checked (tp);
          }
       }
+    else
+      proceed_resume_thread_checked (cur_thr);
 
     disable_commit_resumed.reset_and_commit ();
   }