diff --git a/lldb/include/lldb/Target/ThreadPlan.h b/lldb/include/lldb/Target/ThreadPlan.h
--- a/lldb/include/lldb/Target/ThreadPlan.h
+++ b/lldb/include/lldb/Target/ThreadPlan.h
@@ -81,7 +81,7 @@
 //
 //  Cleaning up after your plans:
 //
-//  When the plan is moved from the plan stack its WillPop method is always
+//  When the plan is moved from the plan stack its DidPop method is always
 //  called, no matter why.  Once it is moved off the plan stack it is done, and
 //  won't get a chance to run again.  So you should undo anything that affects
 //  target state in this method.  But be sure to leave the plan able to
@@ -413,7 +413,7 @@
 
   virtual void DidPush();
 
-  virtual void WillPop();
+  virtual void DidPop();
 
   ThreadPlanKind GetKind() const { return m_kind; }
 
diff --git a/lldb/include/lldb/Target/ThreadPlanCallFunction.h b/lldb/include/lldb/Target/ThreadPlanCallFunction.h
--- a/lldb/include/lldb/Target/ThreadPlanCallFunction.h
+++ b/lldb/include/lldb/Target/ThreadPlanCallFunction.h
@@ -68,10 +68,10 @@
   // been cleaned up.
   lldb::addr_t GetFunctionStackPointer() { return m_function_sp; }
 
-  // Classes that derive from FunctionCaller, and implement their own WillPop
+  // Classes that derive from FunctionCaller, and implement their own DidPop
   // methods should call this so that the thread state gets restored if the
   // plan gets discarded.
-  void WillPop() override;
+  void DidPop() override;
 
   // If the thread plan stops mid-course, this will be the stop reason that
   // interrupted us. Once DoTakedown is called, this will be the real stop
diff --git a/lldb/include/lldb/Target/ThreadPlanCallUserExpression.h b/lldb/include/lldb/Target/ThreadPlanCallUserExpression.h
--- a/lldb/include/lldb/Target/ThreadPlanCallUserExpression.h
+++ b/lldb/include/lldb/Target/ThreadPlanCallUserExpression.h
@@ -32,7 +32,7 @@
 
   void DidPush() override;
 
-  void WillPop() override;
+  void DidPop() override;
 
   lldb::StopInfoSP GetRealStopInfo() override;
 
diff --git a/lldb/include/lldb/Target/ThreadPlanStepOverBreakpoint.h b/lldb/include/lldb/Target/ThreadPlanStepOverBreakpoint.h
--- a/lldb/include/lldb/Target/ThreadPlanStepOverBreakpoint.h
+++ b/lldb/include/lldb/Target/ThreadPlanStepOverBreakpoint.h
@@ -26,7 +26,7 @@
   bool StopOthers() override;
   lldb::StateType GetPlanRunState() override;
   bool WillStop() override;
-  void WillPop() override;
+  void DidPop() override;
   bool MischiefManaged() override;
   void ThreadDestroyed() override;
   void SetAutoContinue(bool do_it);
diff --git a/lldb/source/Target/ThreadPlan.cpp b/lldb/source/Target/ThreadPlan.cpp
--- a/lldb/source/Target/ThreadPlan.cpp
+++ b/lldb/source/Target/ThreadPlan.cpp
@@ -149,7 +149,7 @@
 
 void ThreadPlan::DidPush() {}
 
-void ThreadPlan::WillPop() {}
+void ThreadPlan::DidPop() {}
 
 bool ThreadPlan::OkayToDiscard() {
   return IsMasterPlan() ? m_okay_to_discard : true;
diff --git a/lldb/source/Target/ThreadPlanCallFunction.cpp b/lldb/source/Target/ThreadPlanCallFunction.cpp
--- a/lldb/source/Target/ThreadPlanCallFunction.cpp
+++ b/lldb/source/Target/ThreadPlanCallFunction.cpp
@@ -209,7 +209,7 @@
   }
 }
 
-void ThreadPlanCallFunction::WillPop() { DoTakedown(PlanSucceeded()); }
+void ThreadPlanCallFunction::DidPop() { DoTakedown(PlanSucceeded()); }
 
 void ThreadPlanCallFunction::GetDescription(Stream *s, DescriptionLevel level) {
   if (level == eDescriptionLevelBrief) {
diff --git a/lldb/source/Target/ThreadPlanCallUserExpression.cpp b/lldb/source/Target/ThreadPlanCallUserExpression.cpp
--- a/lldb/source/Target/ThreadPlanCallUserExpression.cpp
+++ b/lldb/source/Target/ThreadPlanCallUserExpression.cpp
@@ -59,8 +59,8 @@
     m_user_expression_sp->WillStartExecuting();
 }
 
-void ThreadPlanCallUserExpression::WillPop() {
-  ThreadPlanCallFunction::WillPop();
+void ThreadPlanCallUserExpression::DidPop() {
+  ThreadPlanCallFunction::DidPop();
   if (m_user_expression_sp)
     m_user_expression_sp.reset();
 }
diff --git a/lldb/source/Target/ThreadPlanStack.cpp b/lldb/source/Target/ThreadPlanStack.cpp
--- a/lldb/source/Target/ThreadPlanStack.cpp
+++ b/lldb/source/Target/ThreadPlanStack.cpp
@@ -150,10 +150,13 @@
   std::lock_guard<std::recursive_mutex> guard(m_stack_mutex);
   assert(m_plans.size() > 1 && "Can't pop the base thread plan");
 
-  lldb::ThreadPlanSP plan_sp = std::move(m_plans.back());
-  m_completed_plans.push_back(plan_sp);
-  plan_sp->WillPop();
+  // Note that moving the top element of the vector would leave it in an
+  // undefined state, and break the guarantee that the stack's thread plans are
+  // all valid.
+  lldb::ThreadPlanSP plan_sp = m_plans.back();
   m_plans.pop_back();
+  m_completed_plans.push_back(plan_sp);
+  plan_sp->DidPop();
   return plan_sp;
 }
 
@@ -161,10 +164,13 @@
   std::lock_guard<std::recursive_mutex> guard(m_stack_mutex);
   assert(m_plans.size() > 1 && "Can't discard the base thread plan");
 
-  lldb::ThreadPlanSP plan_sp = std::move(m_plans.back());
-  m_discarded_plans.push_back(plan_sp);
-  plan_sp->WillPop();
+  // Note that moving the top element of the vector would leave it in an
+  // undefined state, and break the guarantee that the stack's thread plans are
+  // all valid.
+  lldb::ThreadPlanSP plan_sp = m_plans.back();
   m_plans.pop_back();
+  m_discarded_plans.push_back(plan_sp);
+  plan_sp->DidPop();
   return plan_sp;
 }
 
diff --git a/lldb/source/Target/ThreadPlanStepOverBreakpoint.cpp b/lldb/source/Target/ThreadPlanStepOverBreakpoint.cpp
--- a/lldb/source/Target/ThreadPlanStepOverBreakpoint.cpp
+++ b/lldb/source/Target/ThreadPlanStepOverBreakpoint.cpp
@@ -124,9 +124,7 @@
   return true;
 }
 
-void ThreadPlanStepOverBreakpoint::WillPop() {
-  ReenableBreakpointSite();
-}
+void ThreadPlanStepOverBreakpoint::DidPop() { ReenableBreakpointSite(); }
 
 bool ThreadPlanStepOverBreakpoint::MischiefManaged() {
   lldb::addr_t pc_addr = GetThread().GetRegisterContext()->GetPC();