//===-- ThreadPlanStepOut.cpp -----------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "lldb/Target/ThreadPlanStepOut.h"
// C Includes
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "lldb/Breakpoint/Breakpoint.h"
#include "lldb/lldb-private-log.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/Value.h"
#include "lldb/Core/ValueObjectConstResult.h"
#include "lldb/Symbol/Block.h"
#include "lldb/Symbol/Function.h"
#include "lldb/Symbol/Type.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/StopInfo.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/ThreadPlanStepOverRange.h"
using namespace lldb;
using namespace lldb_private;
//----------------------------------------------------------------------
// ThreadPlanStepOut: Step out of the current frame
//----------------------------------------------------------------------
ThreadPlanStepOut::ThreadPlanStepOut
(
Thread &thread,
SymbolContext *context,
bool first_insn,
bool stop_others,
Vote stop_vote,
Vote run_vote,
uint32_t frame_idx
) :
ThreadPlan (ThreadPlan::eKindStepOut, "Step out", thread, stop_vote, run_vote),
m_step_from_context (context),
m_step_from_insn (LLDB_INVALID_ADDRESS),
m_return_bp_id (LLDB_INVALID_BREAK_ID),
m_return_addr (LLDB_INVALID_ADDRESS),
m_first_insn (first_insn),
m_stop_others (stop_others),
m_step_through_inline_plan_sp(),
m_step_out_plan_sp (),
m_immediate_step_from_function(NULL)
{
m_step_from_insn = m_thread.GetRegisterContext()->GetPC(0);
StackFrameSP return_frame_sp (m_thread.GetStackFrameAtIndex(frame_idx + 1));
StackFrameSP immediate_return_from_sp (m_thread.GetStackFrameAtIndex (frame_idx));
if (!return_frame_sp || !immediate_return_from_sp)
return; // we can't do anything here. ValidatePlan() will return false.
m_step_out_to_id = return_frame_sp->GetStackID();
m_immediate_step_from_id = immediate_return_from_sp->GetStackID();
StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID();
// If the frame directly below the one we are returning to is inlined, we have to be
// a little more careful. It is non-trivial to determine the real "return code address" for
// an inlined frame, so we have to work our way to that frame and then step out.
if (immediate_return_from_sp && immediate_return_from_sp->IsInlined())
{
if (frame_idx > 0)
{
// First queue a plan that gets us to this inlined frame, and when we get there we'll queue a second
// plan that walks us out of this frame.
m_step_out_plan_sp.reset (new ThreadPlanStepOut(m_thread,
NULL,
false,
stop_others,
eVoteNoOpinion,
eVoteNoOpinion,
frame_idx - 1));
}
else
{
// If we're already at the inlined frame we're stepping through, then just do that now.
QueueInlinedStepPlan(false);
}
}
else if (return_frame_sp)
{
// Find the return address and set a breakpoint there:
// FIXME - can we do this more securely if we know first_insn?
m_return_addr = return_frame_sp->GetFrameCodeAddress().GetLoadAddress(&m_thread.GetProcess()->GetTarget());
if (m_return_addr == LLDB_INVALID_ADDRESS)
return;
Breakpoint *return_bp = m_thread.CalculateTarget()->CreateBreakpoint (m_return_addr, true).get();
if (return_bp != NULL)
{
return_bp->SetThreadID(m_thread.GetID());
m_return_bp_id = return_bp->GetID();
return_bp->SetBreakpointKind ("step-out");
}
if (immediate_return_from_sp)
{
const SymbolContext &sc = immediate_return_from_sp->GetSymbolContext(eSymbolContextFunction);
if (sc.function)
{
m_immediate_step_from_function = sc.function;
}
}
}
}
void
ThreadPlanStepOut::DidPush()
{
if (m_step_out_plan_sp)
m_thread.QueueThreadPlan(m_step_out_plan_sp, false);
else if (m_step_through_inline_plan_sp)
m_thread.QueueThreadPlan(m_step_through_inline_plan_sp, false);
}
ThreadPlanStepOut::~ThreadPlanStepOut ()
{
if (m_return_bp_id != LLDB_INVALID_BREAK_ID)
m_thread.CalculateTarget()->RemoveBreakpointByID(m_return_bp_id);
}
void
ThreadPlanStepOut::GetDescription (Stream *s, lldb::DescriptionLevel level)
{
if (level == lldb::eDescriptionLevelBrief)
s->Printf ("step out");
else
{
if (m_step_out_plan_sp)
s->Printf ("Stepping out to inlined frame so we can walk through it.");
else if (m_step_through_inline_plan_sp)
s->Printf ("Stepping out by stepping through inlined function.");
else
s->Printf ("Stepping out from address 0x%" PRIx64 " to return address 0x%" PRIx64 " using breakpoint site %d",
(uint64_t)m_step_from_insn,
(uint64_t)m_return_addr,
m_return_bp_id);
}
}
bool
ThreadPlanStepOut::ValidatePlan (Stream *error)
{
if (m_step_out_plan_sp)
return m_step_out_plan_sp->ValidatePlan (error);
else if (m_step_through_inline_plan_sp)
return m_step_through_inline_plan_sp->ValidatePlan (error);
else if (m_return_bp_id == LLDB_INVALID_BREAK_ID)
{
if (error)
error->PutCString("Could not create return address breakpoint.");
return false;
}
else
return true;
}
bool
ThreadPlanStepOut::DoPlanExplainsStop (Event *event_ptr)
{
// If one of our child plans just finished, then we do explain the stop.
if (m_step_out_plan_sp)
{
if (m_step_out_plan_sp->MischiefManaged())
{
// If this one is done, then we are all done.
CalculateReturnValue();
SetPlanComplete();
return true;
}
else
return false;
}
else if (m_step_through_inline_plan_sp)
{
if (m_step_through_inline_plan_sp->MischiefManaged())
return true;
else
return false;
}
// We don't explain signals or breakpoints (breakpoints that handle stepping in or
// out will be handled by a child plan.
StopInfoSP stop_info_sp = GetPrivateStopInfo ();
if (stop_info_sp)
{
StopReason reason = stop_info_sp->GetStopReason();
switch (reason)
{
case eStopReasonBreakpoint:
{
// If this is OUR breakpoint, we're fine, otherwise we don't know why this happened...
BreakpointSiteSP site_sp (m_thread.GetProcess()->GetBreakpointSiteList().FindByID (stop_info_sp->GetValue()));
if (site_sp && site_sp->IsBreakpointAtThisSite (m_return_bp_id))
{
bool done;
StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID();
if (m_step_out_to_id == frame_zero_id)
done = true;
else if (m_step_out_to_id < frame_zero_id)
{
// Either we stepped past the breakpoint, or the stack ID calculation
// was incorrect and we should probably stop.
done = true;
}
else
{
if (m_immediate_step_from_id < frame_zero_id)
done = true;
else
done = false;
}
if (done)
{
CalculateReturnValue();
SetPlanComplete();
}
// If there was only one owner, then we're done. But if we also hit some
// user breakpoint on our way out, we should mark ourselves as done, but
// also not claim to explain the stop, since it is more important to report
// the user breakpoint than the step out completion.
if (site_sp->GetNumberOfOwners() == 1)
return true;
}
return false;
}
case eStopReasonWatchpoint:
case eStopReasonSignal:
case eStopReasonException:
case eStopReasonExec:
case eStopReasonThreadExiting:
return false;
default:
return true;
}
}
return true;
}
bool
ThreadPlanStepOut::ShouldStop (Event *event_ptr)
{
if (IsPlanComplete())
return true;
bool done;
StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID();
if (frame_zero_id < m_step_out_to_id)
done = false;
else
done = true;
if (done)
{
CalculateReturnValue();
SetPlanComplete();
return true;
}
else
{
if (m_step_out_plan_sp)
{
if (m_step_out_plan_sp->MischiefManaged())
{
// Now step through the inlined stack we are in:
if (QueueInlinedStepPlan(true))
{
return false;
}
else
{
CalculateReturnValue();
SetPlanComplete ();
return true;
}
}
else
return m_step_out_plan_sp->ShouldStop(event_ptr);
}
else if (m_step_through_inline_plan_sp)
{
if (m_step_through_inline_plan_sp->MischiefManaged())
{
// We don't calculate the return value here because we don't know how to.
// But in case we had a return value sitting around from our process in
// getting here, let's clear it out.
m_return_valobj_sp.reset();
SetPlanComplete();
return true;
}
else
return m_step_through_inline_plan_sp->ShouldStop(event_ptr);
}
else
return false;
}
}
bool
ThreadPlanStepOut::StopOthers ()
{
return m_stop_others;
}
StateType
ThreadPlanStepOut::GetPlanRunState ()
{
return eStateRunning;
}
bool
ThreadPlanStepOut::DoWillResume (StateType resume_state, bool current_plan)
{
if (m_step_out_plan_sp || m_step_through_inline_plan_sp)
return true;
if (m_return_bp_id == LLDB_INVALID_BREAK_ID)
return false;
if (current_plan)
{
Breakpoint *return_bp = m_thread.CalculateTarget()->GetBreakpointByID(m_return_bp_id).get();
if (return_bp != NULL)
return_bp->SetEnabled (true);
}
return true;
}
bool
ThreadPlanStepOut::WillStop ()
{
if (m_return_bp_id != LLDB_INVALID_BREAK_ID)
{
Breakpoint *return_bp = m_thread.CalculateTarget()->GetBreakpointByID(m_return_bp_id).get();
if (return_bp != NULL)
return_bp->SetEnabled (false);
}
return true;
}
bool
ThreadPlanStepOut::MischiefManaged ()
{
if (IsPlanComplete())
{
// Did I reach my breakpoint? If so I'm done.
//
// I also check the stack depth, since if we've blown past the breakpoint for some
// reason and we're now stopping for some other reason altogether, then we're done
// with this step out operation.
Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
if (log)
log->Printf("Completed step out plan.");
if (m_return_bp_id != LLDB_INVALID_BREAK_ID)
{
m_thread.CalculateTarget()->RemoveBreakpointByID (m_return_bp_id);
m_return_bp_id = LLDB_INVALID_BREAK_ID;
}
ThreadPlan::MischiefManaged ();
return true;
}
else
{
return false;
}
}
bool
ThreadPlanStepOut::QueueInlinedStepPlan (bool queue_now)
{
// Now figure out the range of this inlined block, and set up a "step through range"
// plan for that. If we've been provided with a context, then use the block in that
// context.
StackFrameSP immediate_return_from_sp (m_thread.GetStackFrameAtIndex (0));
if (!immediate_return_from_sp)
return false;
Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
if (log)
{
StreamString s;
immediate_return_from_sp->Dump(&s, true, false);
log->Printf("Queuing inlined frame to step past: %s.", s.GetData());
}
Block *from_block = immediate_return_from_sp->GetFrameBlock();
if (from_block)
{
Block *inlined_block = from_block->GetContainingInlinedBlock();
if (inlined_block)
{
size_t num_ranges = inlined_block->GetNumRanges();
AddressRange inline_range;
if (inlined_block->GetRangeAtIndex(0, inline_range))
{
SymbolContext inlined_sc;
inlined_block->CalculateSymbolContext(&inlined_sc);
inlined_sc.target_sp = GetTarget().shared_from_this();
RunMode run_mode = m_stop_others ? lldb::eOnlyThisThread : lldb::eAllThreads;
ThreadPlanStepOverRange *step_through_inline_plan_ptr = new ThreadPlanStepOverRange(m_thread,
inline_range,
inlined_sc,
run_mode);
step_through_inline_plan_ptr->SetOkayToDiscard(true);
StreamString errors;
if (!step_through_inline_plan_ptr->ValidatePlan(&errors))
{
//FIXME: Log this failure.
delete step_through_inline_plan_ptr;
return false;
}
for (size_t i = 1; i < num_ranges; i++)
{
if (inlined_block->GetRangeAtIndex (i, inline_range))
step_through_inline_plan_ptr->AddRange (inline_range);
}
m_step_through_inline_plan_sp.reset (step_through_inline_plan_ptr);
if (queue_now)
m_thread.QueueThreadPlan (m_step_through_inline_plan_sp, false);
return true;
}
}
}
return false;
}
void
ThreadPlanStepOut::CalculateReturnValue ()
{
if (m_return_valobj_sp)
return;
if (m_immediate_step_from_function != NULL)
{
ClangASTType return_clang_type = m_immediate_step_from_function->GetClangType().GetFunctionReturnType();
if (return_clang_type)
{
lldb::ABISP abi_sp = m_thread.GetProcess()->GetABI();
if (abi_sp)
m_return_valobj_sp = abi_sp->GetReturnValueObject(m_thread, return_clang_type);
}
}
}
bool
ThreadPlanStepOut::IsPlanStale()
{
// If we are still lower on the stack than the frame we are returning to, then
// there's something for us to do. Otherwise, we're stale.
StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID();
if (frame_zero_id < m_step_out_to_id)
return false;
else
return true;
}