| //===-- ThreadPlanStepThrough.cpp -----------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "lldb/Target/ThreadPlanStepThrough.h" |
| #include "lldb/Breakpoint/Breakpoint.h" |
| #include "lldb/Target/DynamicLoader.h" |
| #include "lldb/Target/LanguageRuntime.h" |
| #include "lldb/Target/Process.h" |
| #include "lldb/Target/RegisterContext.h" |
| #include "lldb/Target/Target.h" |
| #include "lldb/Utility/LLDBLog.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. |
| |
| 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 = thread.GetFrameWithStackID(m_stack_id); |
| |
| if (return_frame_sp) { |
| m_backstop_addr = return_frame_sp->GetFrameCodeAddress().GetLoadAddress( |
| thread.CalculateTarget().get()); |
| Breakpoint *return_bp = |
| m_process.GetTarget() |
| .CreateBreakpoint(m_backstop_addr, true, false) |
| .get(); |
| |
| if (return_bp != nullptr) { |
| if (return_bp->IsHardware() && !return_bp->HasResolvedLocations()) |
| m_could_not_resolve_hw_bp = true; |
| return_bp->SetThreadID(m_tid); |
| m_backstop_bkpt_id = return_bp->GetID(); |
| return_bp->SetBreakpointKind("step-through-backstop"); |
| } |
| Log *log = GetLog(LLDBLog::Step); |
| if (log) { |
| LLDB_LOGF(log, "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() { |
| Thread &thread = GetThread(); |
| DynamicLoader *loader = thread.GetProcess()->GetDynamicLoader(); |
| if (loader) |
| m_sub_plan_sp = loader->GetStepThroughTrampolinePlan(thread, m_stop_others); |
| |
| // If the DynamicLoader was unable to provide us with a ThreadPlan, then we |
| // try the LanguageRuntimes. |
| if (!m_sub_plan_sp) { |
| for (LanguageRuntime *runtime : m_process.GetLanguageRuntimes()) { |
| m_sub_plan_sp = |
| runtime->GetStepThroughTrampolinePlan(thread, m_stop_others); |
| |
| if (m_sub_plan_sp) |
| break; |
| } |
| } |
| |
| Log *log = GetLog(LLDBLog::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); |
| LLDB_LOGF(log, "Found step through plan from 0x%" PRIx64 ": %s", |
| current_address, s.GetData()); |
| } else { |
| LLDB_LOGF(log, |
| "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: "); |
| DumpAddress(s->AsRawOstream(), 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); |
| DumpAddress(s->AsRawOstream(), m_backstop_addr, sizeof(addr_t)); |
| } else |
| s->PutCString(" unable to set a backstop breakpoint."); |
| } |
| } |
| |
| bool ThreadPlanStepThrough::ValidatePlan(Stream *error) { |
| if (m_could_not_resolve_hw_bp) { |
| if (error) |
| error->PutCString( |
| "Could not create hardware breakpoint for thread plan."); |
| return false; |
| } |
| |
| if (m_backstop_bkpt_id == LLDB_INVALID_BREAK_ID) { |
| if (error) |
| error->PutCString("Could not create backstop breakpoint."); |
| return false; |
| } |
| |
| if (!m_sub_plan_sp.get()) { |
| if (error) |
| error->PutCString("Does not have a subplan."); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| 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_process.GetTarget().RemoveBreakpointByID(m_backstop_bkpt_id); |
| m_backstop_bkpt_id = LLDB_INVALID_BREAK_ID; |
| m_could_not_resolve_hw_bp = false; |
| } |
| } |
| |
| bool ThreadPlanStepThrough::MischiefManaged() { |
| Log *log = GetLog(LLDBLog::Step); |
| |
| if (!IsPlanComplete()) { |
| return false; |
| } else { |
| LLDB_LOGF(log, "Completed step through step plan."); |
| |
| ClearBackstopBreakpoint(); |
| ThreadPlan::MischiefManaged(); |
| return true; |
| } |
| } |
| |
| bool ThreadPlanStepThrough::HitOurBackstopBreakpoint() { |
| Thread &thread = GetThread(); |
| StopInfoSP stop_info_sp(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_process.GetBreakpointSiteList().FindByID(stop_value); |
| if (cur_site_sp && |
| cur_site_sp->IsBreakpointAtThisSite(m_backstop_bkpt_id)) { |
| StackID cur_frame_zero_id = thread.GetStackFrameAtIndex(0)->GetStackID(); |
| |
| if (cur_frame_zero_id == m_return_stack_id) { |
| Log *log = GetLog(LLDBLog::Step); |
| if (log) |
| log->PutCString("ThreadPlanStepThrough hit backstop breakpoint."); |
| return true; |
| } |
| } |
| } |
| return false; |
| } |