1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
| //===-- ThreadPlanStepOverBreakpoint.cpp ------------------------*- C++ -*-===//
//
// 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/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 = m_thread.GetRegisterContext()->GetPC();
m_breakpoint_site_id =
m_thread.GetProcess()->GetBreakpointSiteList().FindIDByAddress(
m_breakpoint_addr);
}
ThreadPlanStepOverBreakpoint::~ThreadPlanStepOverBreakpoint() {}
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) {
// 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. So our trace step COULD appear as a breakpoint hit if the
// next instruction also contained a breakpoint.
StopReason reason = stop_info_sp->GetStopReason();
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
LLDB_LOGF(log, "Step over breakpoint stopped for reason: %s.",
Thread::StopReasonAsCString(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 = m_thread.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_thread.GetProcess()->GetBreakpointSiteList().FindByAddress(
m_breakpoint_addr));
if (bp_site_sp && bp_site_sp->IsEnabled()) {
m_thread.GetProcess()->DisableBreakpointSite(bp_site_sp.get());
m_reenabled_breakpoint_site = false;
}
}
return true;
}
bool ThreadPlanStepOverBreakpoint::WillStop() {
ReenableBreakpointSite();
return true;
}
void ThreadPlanStepOverBreakpoint::WillPop() {
ReenableBreakpointSite();
}
bool ThreadPlanStepOverBreakpoint::MischiefManaged() {
lldb::addr_t pc_addr = m_thread.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(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_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_thread.GetProcess()->GetBreakpointSiteList().FindByAddress(
m_breakpoint_addr));
if (bp_site_sp) {
m_thread.GetProcess()->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 m_thread.GetRegisterContext()->GetPC() != m_breakpoint_addr;
}
|