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Fix a misunderstanding of the ThreadPlan::OkayToDiscard flag in InferiorCallPOSIX. It was 

set to true, but all plans run by RunThreadPlan need to have this set to false so they will
return control to RunThreadPlan without consulting plans higher on the stack.

Since this seems like a common error, I also modified RunThreadPlan to enforce this behavior.

<rdar://problem/22543166>

llvm-svn: 250084
This commit is contained in:
Jim Ingham 2015-10-12 19:11:03 +00:00
parent 1fd2f08ea9
commit c60963c6c7
2 changed files with 84 additions and 18 deletions
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9
lldb/source/Plugins/Process/Utility/InferiorCallPOSIX.cpp
View File

@ -103,9 +103,6 @@ lldb_private::InferiorCallMmap (Process *process,
if (call_plan_sp)
{
StreamFile error_strm;
// This plan is a utility plan, so set it to discard itself when done.
call_plan_sp->SetIsMasterPlan (true);
call_plan_sp->SetOkayToDiscard(true);
StackFrame *frame = thread->GetStackFrameAtIndex (0).get();
if (frame)
@ -188,9 +185,6 @@ lldb_private::InferiorCallMunmap (Process *process,
if (call_plan_sp)
{
StreamFile error_strm;
// This plan is a utility plan, so set it to discard itself when done.
call_plan_sp->SetIsMasterPlan (true);
call_plan_sp->SetOkayToDiscard(true);
StackFrame *frame = thread->GetStackFrameAtIndex (0).get();
if (frame)
@ -244,9 +238,6 @@ lldb_private::InferiorCall (Process *process,
if (call_plan_sp)
{
StreamString error_strm;
// This plan is a utility plan, so set it to discard itself when done.
call_plan_sp->SetIsMasterPlan (true);
call_plan_sp->SetOkayToDiscard(true);
StackFrame *frame = thread->GetStackFrameAtIndex (0).get();
if (frame)

93
lldb/source/Target/Process.cpp
View File

@ -5367,6 +5367,53 @@ Process::SettingsTerminate ()
Thread::SettingsTerminate ();
}
namespace
{
// RestorePlanState is used to record the "is private", "is master" and "okay to discard" fields of
// the plan we are running, and reset it on Clean or on destruction.
// It will only reset the state once, so you can call Clean and then monkey with the state and it
// won't get reset on you again.
class RestorePlanState
{
public:
RestorePlanState (lldb::ThreadPlanSP thread_plan_sp) :
m_thread_plan_sp(thread_plan_sp),
m_already_reset(false)
{
if (m_thread_plan_sp)
{
m_private = m_thread_plan_sp->GetPrivate();
m_is_master = m_thread_plan_sp->IsMasterPlan();
m_okay_to_discard = m_thread_plan_sp->OkayToDiscard();
}
}
~RestorePlanState()
{
Clean();
}
void
Clean ()
{
if (!m_already_reset && m_thread_plan_sp)
{
m_already_reset = true;
m_thread_plan_sp->SetPrivate(m_private);
m_thread_plan_sp->SetIsMasterPlan (m_is_master);
m_thread_plan_sp->SetOkayToDiscard(m_okay_to_discard);
}
}
private:
lldb::ThreadPlanSP m_thread_plan_sp;
bool m_already_reset;
bool m_private;
bool m_is_master;
bool m_okay_to_discard;
};
}
ExpressionResults
Process::RunThreadPlan (ExecutionContext &exe_ctx,
lldb::ThreadPlanSP &thread_plan_sp,
@ -5400,12 +5447,22 @@ Process::RunThreadPlan (ExecutionContext &exe_ctx,
return eExpressionSetupError;
}
// We need to change some of the thread plan attributes for the thread plan runner. This will restore them
// when we are done:
RestorePlanState thread_plan_restorer(thread_plan_sp);
// We rely on the thread plan we are running returning "PlanCompleted" if when it successfully completes.
// For that to be true the plan can't be private - since private plans suppress themselves in the
// GetCompletedPlan call.
bool orig_plan_private = thread_plan_sp->GetPrivate();
thread_plan_sp->SetPrivate(false);
// The plans run with RunThreadPlan also need to be terminal master plans or when they are done we will end
// up asking the plan above us whether we should stop, which may give the wrong answer.
thread_plan_sp->SetIsMasterPlan (true);
thread_plan_sp->SetOkayToDiscard(false);
if (m_private_state.GetValue() != eStateStopped)
{
@ -5835,10 +5892,10 @@ Process::RunThreadPlan (ExecutionContext &exe_ctx,
{
if (log)
log->PutCString ("Process::RunThreadPlan(): execution completed successfully.");
// Now mark this plan as private so it doesn't get reported as the stop reason
// after this point.
if (thread_plan_sp)
thread_plan_sp->SetPrivate (orig_plan_private);
// Restore the plan state so it will get reported as intended when we are done.
thread_plan_restorer.Clean();
return_value = eExpressionCompleted;
}
else
@ -5851,6 +5908,13 @@ Process::RunThreadPlan (ExecutionContext &exe_ctx,
return_value = eExpressionHitBreakpoint;
if (!options.DoesIgnoreBreakpoints())
{
// Restore the plan state and then force Private to false. We are
// going to stop because of this plan so we need it to become a public
// plan or it won't report correctly when we continue to its termination
// later on.
thread_plan_restorer.Clean();
if (thread_plan_sp)
thread_plan_sp->SetPrivate(false);
event_to_broadcast_sp = event_sp;
}
}
@ -6069,6 +6133,19 @@ Process::RunThreadPlan (ExecutionContext &exe_ctx,
m_public_state.SetValueNoLock(old_state);
}
if (return_value != eExpressionCompleted && log)
{
// Print a backtrace into the log so we can figure out where we are:
StreamString s;
s.PutCString("Thread state after unsuccessful completion: \n");
thread->GetStackFrameStatus (s,
0,
UINT32_MAX,
true,
UINT32_MAX);
log->PutCString(s.GetData());
}
// Restore the thread state if we are going to discard the plan execution. There are three cases where this
// could happen:
// 1) The execution successfully completed
@ -6157,7 +6234,8 @@ Process::RunThreadPlan (ExecutionContext &exe_ctx,
else
ts.Printf("[ip unknown] ");
lldb::StopInfoSP stop_info_sp = thread->GetStopInfo();
// Show the private stop info here, the public stop info will be from the last natural stop.
lldb::StopInfoSP stop_info_sp = thread->GetPrivateStopInfo();
if (stop_info_sp)
{
const char *stop_desc = stop_info_sp->GetDescription();
@ -6183,7 +6261,6 @@ Process::RunThreadPlan (ExecutionContext &exe_ctx,
log->Printf ("Process::RunThreadPlan: ExecutionInterrupted - discarding thread plans up to %p.",
static_cast<void*>(thread_plan_sp.get()));
thread->DiscardThreadPlansUpToPlan (thread_plan_sp);
thread_plan_sp->SetPrivate (orig_plan_private);
}
else
{
@ -6200,7 +6277,6 @@ Process::RunThreadPlan (ExecutionContext &exe_ctx,
if (options.DoesUnwindOnError())
{
thread->DiscardThreadPlansUpToPlan (thread_plan_sp);
thread_plan_sp->SetPrivate (orig_plan_private);
}
}
else
@ -6226,7 +6302,6 @@ Process::RunThreadPlan (ExecutionContext &exe_ctx,
if (log)
log->PutCString("Process::RunThreadPlan(): discarding thread plan 'cause unwind_on_error is set.");
thread->DiscardThreadPlansUpToPlan (thread_plan_sp);
thread_plan_sp->SetPrivate (orig_plan_private);
}
}
}