blob: c039a32f5515215c75064464a9c72d04c7bd6875 [file] [log] [blame]
//===-- ThreadPlanStepThrough.cpp -------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// C Includes
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "lldb/Target/ThreadPlanStepThrough.h"
#include "lldb/Breakpoint/Breakpoint.h"
#include "lldb/Target/DynamicLoader.h"
#include "lldb/Target/ObjCLanguageRuntime.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/Target.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/Stream.h"
using namespace lldb;
using namespace lldb_private;
//----------------------------------------------------------------------
// ThreadPlanStepThrough: If the current instruction is a trampoline, step
// through it If it is the beginning of the prologue of a function, step
// through that as well.
// FIXME: At present only handles DYLD trampolines.
//----------------------------------------------------------------------
ThreadPlanStepThrough::ThreadPlanStepThrough(Thread &thread,
StackID &m_stack_id,
bool stop_others)
: ThreadPlan(ThreadPlan::eKindStepThrough,
"Step through trampolines and prologues", thread,
eVoteNoOpinion, eVoteNoOpinion),
m_start_address(0), m_backstop_bkpt_id(LLDB_INVALID_BREAK_ID),
m_backstop_addr(LLDB_INVALID_ADDRESS), m_return_stack_id(m_stack_id),
m_stop_others(stop_others) {
LookForPlanToStepThroughFromCurrentPC();
// If we don't get a valid step through plan, don't bother to set up a
// backstop.
if (m_sub_plan_sp) {
m_start_address = GetThread().GetRegisterContext()->GetPC(0);
// We are going to return back to the concrete frame 1, we might pass by
// some inlined code that we're in the middle of by doing this, but it's
// easier than trying to figure out where the inlined code might return to.
StackFrameSP return_frame_sp = m_thread.GetFrameWithStackID(m_stack_id);
if (return_frame_sp) {
m_backstop_addr = return_frame_sp->GetFrameCodeAddress().GetLoadAddress(
m_thread.CalculateTarget().get());
Breakpoint *return_bp =
m_thread.GetProcess()
->GetTarget()
.CreateBreakpoint(m_backstop_addr, true, false)
.get();
if (return_bp != nullptr) {
return_bp->SetThreadID(m_thread.GetID());
m_backstop_bkpt_id = return_bp->GetID();
return_bp->SetBreakpointKind("step-through-backstop");
}
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
if (log) {
log->Printf("Setting backstop breakpoint %d at address: 0x%" PRIx64,
m_backstop_bkpt_id, m_backstop_addr);
}
}
}
}
ThreadPlanStepThrough::~ThreadPlanStepThrough() { ClearBackstopBreakpoint(); }
void ThreadPlanStepThrough::DidPush() {
if (m_sub_plan_sp)
PushPlan(m_sub_plan_sp);
}
void ThreadPlanStepThrough::LookForPlanToStepThroughFromCurrentPC() {
DynamicLoader *loader = m_thread.GetProcess()->GetDynamicLoader();
if (loader)
m_sub_plan_sp =
loader->GetStepThroughTrampolinePlan(m_thread, m_stop_others);
// If that didn't come up with anything, try the ObjC runtime plugin:
if (!m_sub_plan_sp.get()) {
ObjCLanguageRuntime *objc_runtime =
m_thread.GetProcess()->GetObjCLanguageRuntime();
if (objc_runtime)
m_sub_plan_sp =
objc_runtime->GetStepThroughTrampolinePlan(m_thread, m_stop_others);
}
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
if (log) {
lldb::addr_t current_address = GetThread().GetRegisterContext()->GetPC(0);
if (m_sub_plan_sp) {
StreamString s;
m_sub_plan_sp->GetDescription(&s, lldb::eDescriptionLevelFull);
log->Printf("Found step through plan from 0x%" PRIx64 ": %s",
current_address, s.GetData());
} else {
log->Printf("Couldn't find step through plan from address 0x%" PRIx64 ".",
current_address);
}
}
}
void ThreadPlanStepThrough::GetDescription(Stream *s,
lldb::DescriptionLevel level) {
if (level == lldb::eDescriptionLevelBrief)
s->Printf("Step through");
else {
s->PutCString("Stepping through trampoline code from: ");
s->Address(m_start_address, sizeof(addr_t));
if (m_backstop_bkpt_id != LLDB_INVALID_BREAK_ID) {
s->Printf(" with backstop breakpoint ID: %d at address: ",
m_backstop_bkpt_id);
s->Address(m_backstop_addr, sizeof(addr_t));
} else
s->PutCString(" unable to set a backstop breakpoint.");
}
}
bool ThreadPlanStepThrough::ValidatePlan(Stream *error) {
return m_sub_plan_sp.get() != nullptr;
}
bool ThreadPlanStepThrough::DoPlanExplainsStop(Event *event_ptr) {
// If we have a sub-plan, it will have been asked first if we explain the
// stop, and we won't get asked. The only time we would be the one directly
// asked this question is if we hit our backstop breakpoint.
return HitOurBackstopBreakpoint();
}
bool ThreadPlanStepThrough::ShouldStop(Event *event_ptr) {
// If we've already marked ourselves done, then we're done...
if (IsPlanComplete())
return true;
// First, did we hit the backstop breakpoint?
if (HitOurBackstopBreakpoint()) {
SetPlanComplete(true);
return true;
}
// If we don't have a sub-plan, then we're also done (can't see how we would
// ever get here without a plan, but just in case.
if (!m_sub_plan_sp) {
SetPlanComplete();
return true;
}
// If the current sub plan is not done, we don't want to stop. Actually, we
// probably won't ever get here in this state, since we generally won't get
// asked any questions if out current sub-plan is not done...
if (!m_sub_plan_sp->IsPlanComplete())
return false;
// If our current sub plan failed, then let's just run to our backstop. If
// we can't do that then just stop.
if (!m_sub_plan_sp->PlanSucceeded()) {
if (m_backstop_bkpt_id != LLDB_INVALID_BREAK_ID) {
m_sub_plan_sp.reset();
return false;
} else {
SetPlanComplete(false);
return true;
}
}
// Next see if there is a specific step through plan at our current pc (these
// might chain, for instance stepping through a dylib trampoline to the objc
// dispatch function...)
LookForPlanToStepThroughFromCurrentPC();
if (m_sub_plan_sp) {
PushPlan(m_sub_plan_sp);
return false;
} else {
SetPlanComplete();
return true;
}
}
bool ThreadPlanStepThrough::StopOthers() { return m_stop_others; }
StateType ThreadPlanStepThrough::GetPlanRunState() { return eStateRunning; }
bool ThreadPlanStepThrough::DoWillResume(StateType resume_state,
bool current_plan) {
return true;
}
bool ThreadPlanStepThrough::WillStop() { return true; }
void ThreadPlanStepThrough::ClearBackstopBreakpoint() {
if (m_backstop_bkpt_id != LLDB_INVALID_BREAK_ID) {
m_thread.GetProcess()->GetTarget().RemoveBreakpointByID(m_backstop_bkpt_id);
m_backstop_bkpt_id = LLDB_INVALID_BREAK_ID;
}
}
bool ThreadPlanStepThrough::MischiefManaged() {
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
if (!IsPlanComplete()) {
return false;
} else {
if (log)
log->Printf("Completed step through step plan.");
ClearBackstopBreakpoint();
ThreadPlan::MischiefManaged();
return true;
}
}
bool ThreadPlanStepThrough::HitOurBackstopBreakpoint() {
StopInfoSP stop_info_sp(m_thread.GetStopInfo());
if (stop_info_sp && stop_info_sp->GetStopReason() == eStopReasonBreakpoint) {
break_id_t stop_value = (break_id_t)stop_info_sp->GetValue();
BreakpointSiteSP cur_site_sp =
m_thread.GetProcess()->GetBreakpointSiteList().FindByID(stop_value);
if (cur_site_sp &&
cur_site_sp->IsBreakpointAtThisSite(m_backstop_bkpt_id)) {
StackID cur_frame_zero_id =
m_thread.GetStackFrameAtIndex(0)->GetStackID();
if (cur_frame_zero_id == m_return_stack_id) {
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
if (log)
log->PutCString("ThreadPlanStepThrough hit backstop breakpoint.");
return true;
}
}
}
return false;
}