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//===-- ThreadPlanStepOverBreakpoint.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/ThreadPlanStepOverBreakpoint.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Utility/LLDBLog.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/Stream.h"
using namespace lldb;
using namespace lldb_private;
// ThreadPlanStepOverBreakpoint: Single steps over a breakpoint bp_site_sp at
// the pc.
ThreadPlanStepOverBreakpoint::ThreadPlanStepOverBreakpoint(Thread &thread)
: ThreadPlan(
ThreadPlan::eKindStepOverBreakpoint, "Step over breakpoint trap",
thread, eVoteNo,
eVoteNoOpinion), // We need to report the run since this happens
// first in the thread plan stack when stepping over
// a breakpoint
m_breakpoint_addr(LLDB_INVALID_ADDRESS),
m_auto_continue(false), m_reenabled_breakpoint_site(false)
{
m_breakpoint_addr = thread.GetRegisterContext()->GetPC();
m_breakpoint_site_id =
thread.GetProcess()->GetBreakpointSiteList().FindIDByAddress(
m_breakpoint_addr);
}
ThreadPlanStepOverBreakpoint::~ThreadPlanStepOverBreakpoint() = default;
void ThreadPlanStepOverBreakpoint::GetDescription(
Stream *s, lldb::DescriptionLevel level) {
s->Printf("Single stepping past breakpoint site %" PRIu64 " at 0x%" PRIx64,
m_breakpoint_site_id, (uint64_t)m_breakpoint_addr);
}
bool ThreadPlanStepOverBreakpoint::ValidatePlan(Stream *error) { return true; }
bool ThreadPlanStepOverBreakpoint::DoPlanExplainsStop(Event *event_ptr) {
StopInfoSP stop_info_sp = GetPrivateStopInfo();
if (stop_info_sp) {
StopReason reason = stop_info_sp->GetStopReason();
Log *log = GetLog(LLDBLog::Step);
LLDB_LOG(log, "Step over breakpoint stopped for reason: {0}.",
Thread::StopReasonAsString(reason));
switch (reason) {
case eStopReasonTrace:
case eStopReasonNone:
return true;
case eStopReasonBreakpoint:
{
// It's a little surprising that we stop here for a breakpoint hit.
// However, when you single step ONTO a breakpoint we still want to call
// that a breakpoint hit, and trigger the actions, etc. Otherwise you
// would see the PC at the breakpoint without having triggered the
// actions, then you'd continue, the PC wouldn't change, and you'd see
// the breakpoint hit, which would be odd. So the lower levels fake
// "step onto breakpoint address" and return that as a breakpoint hit.
// So our trace step COULD appear as a breakpoint hit if the next
// instruction also contained a breakpoint. We don't want to handle
// that, since we really don't know what to do with breakpoint hits.
// But make sure we don't set ourselves to auto-continue or we'll wrench
// control away from the plans that can deal with this.
// Be careful, however, as we may have "seen a breakpoint under the PC
// because we stopped without changing the PC, in which case we do want
// to re-claim this stop so we'll try again.
lldb::addr_t pc_addr = GetThread().GetRegisterContext()->GetPC();
if (pc_addr == m_breakpoint_addr) {
LLDB_LOGF(log,
"Got breakpoint stop reason but pc: 0x%" PRIx64
"hasn't changed.",
pc_addr);
return true;
}
SetAutoContinue(false);
return false;
}
default:
return false;
}
}
return false;
}
bool ThreadPlanStepOverBreakpoint::ShouldStop(Event *event_ptr) {
return !ShouldAutoContinue(event_ptr);
}
bool ThreadPlanStepOverBreakpoint::StopOthers() { return true; }
StateType ThreadPlanStepOverBreakpoint::GetPlanRunState() {
return eStateStepping;
}
bool ThreadPlanStepOverBreakpoint::DoWillResume(StateType resume_state,
bool current_plan) {
if (current_plan) {
BreakpointSiteSP bp_site_sp(
m_process.GetBreakpointSiteList().FindByAddress(m_breakpoint_addr));
if (bp_site_sp && bp_site_sp->IsEnabled()) {
m_process.DisableBreakpointSite(bp_site_sp.get());
m_reenabled_breakpoint_site = false;
}
}
return true;
}
bool ThreadPlanStepOverBreakpoint::WillStop() {
ReenableBreakpointSite();
return true;
}
void ThreadPlanStepOverBreakpoint::DidPop() { ReenableBreakpointSite(); }
bool ThreadPlanStepOverBreakpoint::MischiefManaged() {
lldb::addr_t pc_addr = GetThread().GetRegisterContext()->GetPC();
if (pc_addr == m_breakpoint_addr) {
// If we are still at the PC of our breakpoint, then for some reason we
// didn't get a chance to run.
return false;
} else {
Log *log = GetLog(LLDBLog::Step);
LLDB_LOGF(log, "Completed step over breakpoint plan.");
// Otherwise, re-enable the breakpoint we were stepping over, and we're
// done.
ReenableBreakpointSite();
ThreadPlan::MischiefManaged();
return true;
}
}
void ThreadPlanStepOverBreakpoint::ReenableBreakpointSite() {
if (!m_reenabled_breakpoint_site) {
m_reenabled_breakpoint_site = true;
BreakpointSiteSP bp_site_sp(
m_process.GetBreakpointSiteList().FindByAddress(m_breakpoint_addr));
if (bp_site_sp) {
m_process.EnableBreakpointSite(bp_site_sp.get());
}
}
}
void ThreadPlanStepOverBreakpoint::ThreadDestroyed() {
ReenableBreakpointSite();
}
void ThreadPlanStepOverBreakpoint::SetAutoContinue(bool do_it) {
m_auto_continue = do_it;
}
bool ThreadPlanStepOverBreakpoint::ShouldAutoContinue(Event *event_ptr) {
return m_auto_continue;
}
bool ThreadPlanStepOverBreakpoint::IsPlanStale() {
return GetThread().GetRegisterContext()->GetPC() != m_breakpoint_addr;
}
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