1 //===-- ThreadPlanStepOverBreakpoint.cpp ------------------------*- C++ -*-===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 #include "lldb/Target/ThreadPlanStepOverBreakpoint.h"
11 #include "lldb/Target/Process.h"
12 #include "lldb/Target/RegisterContext.h"
13 #include "lldb/Utility/Log.h"
14 #include "lldb/Utility/Stream.h"
17 using namespace lldb_private;
19 // ThreadPlanStepOverBreakpoint: Single steps over a breakpoint bp_site_sp at
22 ThreadPlanStepOverBreakpoint::ThreadPlanStepOverBreakpoint(Thread &thread)
24 ThreadPlan::eKindStepOverBreakpoint, "Step over breakpoint trap",
26 eVoteNoOpinion), // We need to report the run since this happens
27 // first in the thread plan stack when stepping over
29 m_breakpoint_addr(LLDB_INVALID_ADDRESS),
30 m_auto_continue(false), m_reenabled_breakpoint_site(false)
33 m_breakpoint_addr = m_thread.GetRegisterContext()->GetPC();
34 m_breakpoint_site_id =
35 m_thread.GetProcess()->GetBreakpointSiteList().FindIDByAddress(
39 ThreadPlanStepOverBreakpoint::~ThreadPlanStepOverBreakpoint() {}
41 void ThreadPlanStepOverBreakpoint::GetDescription(
42 Stream *s, lldb::DescriptionLevel level) {
43 s->Printf("Single stepping past breakpoint site %" PRIu64 " at 0x%" PRIx64,
44 m_breakpoint_site_id, (uint64_t)m_breakpoint_addr);
47 bool ThreadPlanStepOverBreakpoint::ValidatePlan(Stream *error) { return true; }
49 bool ThreadPlanStepOverBreakpoint::DoPlanExplainsStop(Event *event_ptr) {
50 StopInfoSP stop_info_sp = GetPrivateStopInfo();
52 // It's a little surprising that we stop here for a breakpoint hit.
53 // However, when you single step ONTO a breakpoint we still want to call
54 // that a breakpoint hit, and trigger the actions, etc. Otherwise you
56 // PC at the breakpoint without having triggered the actions, then you'd
57 // continue, the PC wouldn't change,
58 // and you'd see the breakpoint hit, which would be odd. So the lower
59 // levels fake "step onto breakpoint address" and return that as a
60 // breakpoint. So our trace step COULD appear as a breakpoint hit if the
61 // next instruction also contained a breakpoint.
62 StopReason reason = stop_info_sp->GetStopReason();
64 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
67 log->Printf("Step over breakpoint stopped for reason: %s.",
68 Thread::StopReasonAsCString(reason));
71 case eStopReasonTrace:
74 case eStopReasonBreakpoint:
76 // It's a little surprising that we stop here for a breakpoint hit.
77 // However, when you single step ONTO a breakpoint we still want to call
78 // that a breakpoint hit, and trigger the actions, etc. Otherwise you
79 // would see the PC at the breakpoint without having triggered the
80 // actions, then you'd continue, the PC wouldn't change, and you'd see
81 // the breakpoint hit, which would be odd. So the lower levels fake
82 // "step onto breakpoint address" and return that as a breakpoint hit.
83 // So our trace step COULD appear as a breakpoint hit if the next
84 // instruction also contained a breakpoint. We don't want to handle
85 // that, since we really don't know what to do with breakpoint hits.
86 // But make sure we don't set ourselves to auto-continue or we'll wrench
87 // control away from the plans that can deal with this.
88 // Be careful, however, as we may have "seen a breakpoint under the PC
89 // because we stopped without changing the PC, in which case we do want
90 // to re-claim this stop so we'll try again.
91 lldb::addr_t pc_addr = m_thread.GetRegisterContext()->GetPC();
93 if (pc_addr == m_breakpoint_addr) {
95 log->Printf("Got breakpoint stop reason but pc: 0x%" PRIx64
96 "hasn't changed.", pc_addr);
100 SetAutoContinue(false);
110 bool ThreadPlanStepOverBreakpoint::ShouldStop(Event *event_ptr) {
111 return !ShouldAutoContinue(event_ptr);
114 bool ThreadPlanStepOverBreakpoint::StopOthers() { return true; }
116 StateType ThreadPlanStepOverBreakpoint::GetPlanRunState() {
117 return eStateStepping;
120 bool ThreadPlanStepOverBreakpoint::DoWillResume(StateType resume_state,
123 BreakpointSiteSP bp_site_sp(
124 m_thread.GetProcess()->GetBreakpointSiteList().FindByAddress(
126 if (bp_site_sp && bp_site_sp->IsEnabled()) {
127 m_thread.GetProcess()->DisableBreakpointSite(bp_site_sp.get());
128 m_reenabled_breakpoint_site = false;
134 bool ThreadPlanStepOverBreakpoint::WillStop() {
135 ReenableBreakpointSite();
139 void ThreadPlanStepOverBreakpoint::WillPop() {
140 ReenableBreakpointSite();
143 bool ThreadPlanStepOverBreakpoint::MischiefManaged() {
144 lldb::addr_t pc_addr = m_thread.GetRegisterContext()->GetPC();
146 if (pc_addr == m_breakpoint_addr) {
147 // If we are still at the PC of our breakpoint, then for some reason we
148 // didn't get a chance to run.
151 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
153 log->Printf("Completed step over breakpoint plan.");
154 // Otherwise, re-enable the breakpoint we were stepping over, and we're
156 ReenableBreakpointSite();
157 ThreadPlan::MischiefManaged();
162 void ThreadPlanStepOverBreakpoint::ReenableBreakpointSite() {
163 if (!m_reenabled_breakpoint_site) {
164 m_reenabled_breakpoint_site = true;
165 BreakpointSiteSP bp_site_sp(
166 m_thread.GetProcess()->GetBreakpointSiteList().FindByAddress(
169 m_thread.GetProcess()->EnableBreakpointSite(bp_site_sp.get());
173 void ThreadPlanStepOverBreakpoint::ThreadDestroyed() {
174 ReenableBreakpointSite();
177 void ThreadPlanStepOverBreakpoint::SetAutoContinue(bool do_it) {
178 m_auto_continue = do_it;
181 bool ThreadPlanStepOverBreakpoint::ShouldAutoContinue(Event *event_ptr) {
182 return m_auto_continue;
185 bool ThreadPlanStepOverBreakpoint::IsPlanStale() {
186 return m_thread.GetRegisterContext()->GetPC() != m_breakpoint_addr;