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//===-- ThreadPlanStepUntil.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/ThreadPlanStepUntil.h"
#include "lldb/Breakpoint/Breakpoint.h"
#include "lldb/Symbol/SymbolContextScope.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/StopInfo.h"
#include "lldb/Target/Target.h"
#include "lldb/Utility/Log.h"
using namespace lldb;
using namespace lldb_private;
// ThreadPlanStepUntil: Run until we reach a given line number or step out of
// the current frame
ThreadPlanStepUntil::ThreadPlanStepUntil(Thread &thread,
lldb::addr_t *address_list,
size_t num_addresses, bool stop_others,
uint32_t frame_idx)
: ThreadPlan(ThreadPlan::eKindStepUntil, "Step until", thread,
eVoteNoOpinion, eVoteNoOpinion),
m_step_from_insn(LLDB_INVALID_ADDRESS),
m_return_bp_id(LLDB_INVALID_BREAK_ID),
m_return_addr(LLDB_INVALID_ADDRESS), m_stepped_out(false),
m_should_stop(false), m_ran_analyze(false), m_explains_stop(false),
m_until_points(), m_stop_others(stop_others) {
// Stash away our "until" addresses:
TargetSP target_sp(thread.CalculateTarget());
StackFrameSP frame_sp(thread.GetStackFrameAtIndex(frame_idx));
if (frame_sp) {
m_step_from_insn = frame_sp->GetStackID().GetPC();
// Find the return address and set a breakpoint there:
// FIXME - can we do this more securely if we know first_insn?
StackFrameSP return_frame_sp(thread.GetStackFrameAtIndex(frame_idx + 1));
if (return_frame_sp) {
// TODO: add inline functionality
m_return_addr = return_frame_sp->GetStackID().GetPC();
Breakpoint *return_bp =
target_sp->CreateBreakpoint(m_return_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_return_bp_id = return_bp->GetID();
return_bp->SetBreakpointKind("until-return-backstop");
}
}
m_stack_id = frame_sp->GetStackID();
// Now set breakpoints on all our return addresses:
for (size_t i = 0; i < num_addresses; i++) {
Breakpoint *until_bp =
target_sp->CreateBreakpoint(address_list[i], true, false).get();
if (until_bp != nullptr) {
until_bp->SetThreadID(m_tid);
m_until_points[address_list[i]] = until_bp->GetID();
until_bp->SetBreakpointKind("until-target");
} else {
m_until_points[address_list[i]] = LLDB_INVALID_BREAK_ID;
}
}
}
}
ThreadPlanStepUntil::~ThreadPlanStepUntil() { Clear(); }
void ThreadPlanStepUntil::Clear() {
Target &target = GetTarget();
if (m_return_bp_id != LLDB_INVALID_BREAK_ID) {
target.RemoveBreakpointByID(m_return_bp_id);
m_return_bp_id = LLDB_INVALID_BREAK_ID;
}
until_collection::iterator pos, end = m_until_points.end();
for (pos = m_until_points.begin(); pos != end; pos++) {
target.RemoveBreakpointByID((*pos).second);
}
m_until_points.clear();
m_could_not_resolve_hw_bp = false;
}
void ThreadPlanStepUntil::GetDescription(Stream *s,
lldb::DescriptionLevel level) {
if (level == lldb::eDescriptionLevelBrief) {
s->Printf("step until");
if (m_stepped_out)
s->Printf(" - stepped out");
} else {
if (m_until_points.size() == 1)
s->Printf("Stepping from address 0x%" PRIx64 " until we reach 0x%" PRIx64
" using breakpoint %d",
(uint64_t)m_step_from_insn,
(uint64_t)(*m_until_points.begin()).first,
(*m_until_points.begin()).second);
else {
until_collection::iterator pos, end = m_until_points.end();
s->Printf("Stepping from address 0x%" PRIx64 " until we reach one of:",
(uint64_t)m_step_from_insn);
for (pos = m_until_points.begin(); pos != end; pos++) {
s->Printf("\n\t0x%" PRIx64 " (bp: %d)", (uint64_t)(*pos).first,
(*pos).second);
}
}
s->Printf(" stepped out address is 0x%" PRIx64 ".",
(uint64_t)m_return_addr);
}
}
bool ThreadPlanStepUntil::ValidatePlan(Stream *error) {
if (m_could_not_resolve_hw_bp) {
if (error)
error->PutCString(
"Could not create hardware breakpoint for thread plan.");
return false;
} else if (m_return_bp_id == LLDB_INVALID_BREAK_ID) {
if (error)
error->PutCString("Could not create return breakpoint.");
return false;
} else {
until_collection::iterator pos, end = m_until_points.end();
for (pos = m_until_points.begin(); pos != end; pos++) {
if (!LLDB_BREAK_ID_IS_VALID((*pos).second))
return false;
}
return true;
}
}
void ThreadPlanStepUntil::AnalyzeStop() {
if (m_ran_analyze)
return;
StopInfoSP stop_info_sp = GetPrivateStopInfo();
m_should_stop = true;
m_explains_stop = false;
if (stop_info_sp) {
StopReason reason = stop_info_sp->GetStopReason();
if (reason == eStopReasonBreakpoint) {
// If this is OUR breakpoint, we're fine, otherwise we don't know why
// this happened...
BreakpointSiteSP this_site =
m_process.GetBreakpointSiteList().FindByID(stop_info_sp->GetValue());
if (!this_site) {
m_explains_stop = false;
return;
}
if (this_site->IsBreakpointAtThisSite(m_return_bp_id)) {
// If we are at our "step out" breakpoint, and the stack depth has
// shrunk, then this is indeed our stop. If the stack depth has grown,
// then we've hit our step out breakpoint recursively. If we are the
// only breakpoint at that location, then we do explain the stop, and
// we'll just continue. If there was another breakpoint here, then we
// don't explain the stop, but we won't mark ourselves Completed,
// because maybe that breakpoint will continue, and then we'll finish
// the "until".
bool done;
StackID cur_frame_zero_id;
done = (m_stack_id < cur_frame_zero_id);
if (done) {
m_stepped_out = true;
SetPlanComplete();
} else
m_should_stop = false;
if (this_site->GetNumberOfOwners() == 1)
m_explains_stop = true;
else
m_explains_stop = false;
return;
} else {
// Check if we've hit one of our "until" breakpoints.
until_collection::iterator pos, end = m_until_points.end();
for (pos = m_until_points.begin(); pos != end; pos++) {
if (this_site->IsBreakpointAtThisSite((*pos).second)) {
// If we're at the right stack depth, then we're done.
Thread &thread = GetThread();
bool done;
StackID frame_zero_id =
thread.GetStackFrameAtIndex(0)->GetStackID();
if (frame_zero_id == m_stack_id)
done = true;
else if (frame_zero_id < m_stack_id)
done = false;
else {
StackFrameSP older_frame_sp = thread.GetStackFrameAtIndex(1);
// But if we can't even unwind one frame we should just get out
// of here & stop...
if (older_frame_sp) {
const SymbolContext &older_context =
older_frame_sp->GetSymbolContext(eSymbolContextEverything);
SymbolContext stack_context;
m_stack_id.GetSymbolContextScope()->CalculateSymbolContext(
&stack_context);
done = (older_context == stack_context);
} else
done = false;
}
if (done)
SetPlanComplete();
else
m_should_stop = false;
// Otherwise we've hit this breakpoint recursively. If we're the
// only breakpoint here, then we do explain the stop, and we'll
// continue. If not then we should let higher plans handle this
// stop.
if (this_site->GetNumberOfOwners() == 1)
m_explains_stop = true;
else {
m_should_stop = true;
m_explains_stop = false;
}
return;
}
}
}
// If we get here we haven't hit any of our breakpoints, so let the
// higher plans take care of the stop.
m_explains_stop = false;
return;
} else if (IsUsuallyUnexplainedStopReason(reason)) {
m_explains_stop = false;
} else {
m_explains_stop = true;
}
}
}
bool ThreadPlanStepUntil::DoPlanExplainsStop(Event *event_ptr) {
// We don't explain signals or breakpoints (breakpoints that handle stepping
// in or out will be handled by a child plan.
AnalyzeStop();
return m_explains_stop;
}
bool ThreadPlanStepUntil::ShouldStop(Event *event_ptr) {
// If we've told our self in ExplainsStop that we plan to continue, then do
// so here. Otherwise, as long as this thread has stopped for a reason, we
// will stop.
StopInfoSP stop_info_sp = GetPrivateStopInfo();
if (!stop_info_sp || stop_info_sp->GetStopReason() == eStopReasonNone)
return false;
AnalyzeStop();
return m_should_stop;
}
bool ThreadPlanStepUntil::StopOthers() { return m_stop_others; }
StateType ThreadPlanStepUntil::GetPlanRunState() { return eStateRunning; }
bool ThreadPlanStepUntil::DoWillResume(StateType resume_state,
bool current_plan) {
if (current_plan) {
Target &target = GetTarget();
Breakpoint *return_bp = target.GetBreakpointByID(m_return_bp_id).get();
if (return_bp != nullptr)
return_bp->SetEnabled(true);
until_collection::iterator pos, end = m_until_points.end();
for (pos = m_until_points.begin(); pos != end; pos++) {
Breakpoint *until_bp = target.GetBreakpointByID((*pos).second).get();
if (until_bp != nullptr)
until_bp->SetEnabled(true);
}
}
m_should_stop = true;
m_ran_analyze = false;
m_explains_stop = false;
return true;
}
bool ThreadPlanStepUntil::WillStop() {
Target &target = GetTarget();
Breakpoint *return_bp = target.GetBreakpointByID(m_return_bp_id).get();
if (return_bp != nullptr)
return_bp->SetEnabled(false);
until_collection::iterator pos, end = m_until_points.end();
for (pos = m_until_points.begin(); pos != end; pos++) {
Breakpoint *until_bp = target.GetBreakpointByID((*pos).second).get();
if (until_bp != nullptr)
until_bp->SetEnabled(false);
}
return true;
}
bool ThreadPlanStepUntil::MischiefManaged() {
// I'm letting "PlanExplainsStop" do all the work, and just reporting that
// here.
bool done = false;
if (IsPlanComplete()) {
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
LLDB_LOGF(log, "Completed step until plan.");
Clear();
done = true;
}
if (done)
ThreadPlan::MischiefManaged();
return done;
}