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comparison lldb/source/Target/ThreadPlanStepUntil.cpp @ 150:1d019706d866

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LLVM10
author anatofuz
date Thu, 13 Feb 2020 15:10:13 +0900
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children 0572611fdcc8
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147:c2174574ed3a 150:1d019706d866
1 //===-- ThreadPlanStepUntil.cpp -------------------------------------------===//
2 //
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
6 //
7 //===----------------------------------------------------------------------===//
8
9 #include "lldb/Target/ThreadPlanStepUntil.h"
10
11 #include "lldb/Breakpoint/Breakpoint.h"
12 #include "lldb/Symbol/SymbolContextScope.h"
13 #include "lldb/Target/Process.h"
14 #include "lldb/Target/RegisterContext.h"
15 #include "lldb/Target/StopInfo.h"
16 #include "lldb/Target/Target.h"
17 #include "lldb/Utility/Log.h"
18
19 using namespace lldb;
20 using namespace lldb_private;
21
22 // ThreadPlanStepUntil: Run until we reach a given line number or step out of
23 // the current frame
24
25 ThreadPlanStepUntil::ThreadPlanStepUntil(Thread &thread,
26 lldb::addr_t *address_list,
27 size_t num_addresses, bool stop_others,
28 uint32_t frame_idx)
29 : ThreadPlan(ThreadPlan::eKindStepUntil, "Step until", thread,
30 eVoteNoOpinion, eVoteNoOpinion),
31 m_step_from_insn(LLDB_INVALID_ADDRESS),
32 m_return_bp_id(LLDB_INVALID_BREAK_ID),
33 m_return_addr(LLDB_INVALID_ADDRESS), m_stepped_out(false),
34 m_should_stop(false), m_ran_analyze(false), m_explains_stop(false),
35 m_until_points(), m_stop_others(stop_others) {
36 // Stash away our "until" addresses:
37 TargetSP target_sp(m_thread.CalculateTarget());
38
39 StackFrameSP frame_sp(m_thread.GetStackFrameAtIndex(frame_idx));
40 if (frame_sp) {
41 m_step_from_insn = frame_sp->GetStackID().GetPC();
42 lldb::user_id_t thread_id = m_thread.GetID();
43
44 // Find the return address and set a breakpoint there:
45 // FIXME - can we do this more securely if we know first_insn?
46
47 StackFrameSP return_frame_sp(m_thread.GetStackFrameAtIndex(frame_idx + 1));
48 if (return_frame_sp) {
49 // TODO: add inline functionality
50 m_return_addr = return_frame_sp->GetStackID().GetPC();
51 Breakpoint *return_bp =
52 target_sp->CreateBreakpoint(m_return_addr, true, false).get();
53
54 if (return_bp != nullptr) {
55 if (return_bp->IsHardware() && !return_bp->HasResolvedLocations())
56 m_could_not_resolve_hw_bp = true;
57 return_bp->SetThreadID(thread_id);
58 m_return_bp_id = return_bp->GetID();
59 return_bp->SetBreakpointKind("until-return-backstop");
60 }
61 }
62
63 m_stack_id = frame_sp->GetStackID();
64
65 // Now set breakpoints on all our return addresses:
66 for (size_t i = 0; i < num_addresses; i++) {
67 Breakpoint *until_bp =
68 target_sp->CreateBreakpoint(address_list[i], true, false).get();
69 if (until_bp != nullptr) {
70 until_bp->SetThreadID(thread_id);
71 m_until_points[address_list[i]] = until_bp->GetID();
72 until_bp->SetBreakpointKind("until-target");
73 } else {
74 m_until_points[address_list[i]] = LLDB_INVALID_BREAK_ID;
75 }
76 }
77 }
78 }
79
80 ThreadPlanStepUntil::~ThreadPlanStepUntil() { Clear(); }
81
82 void ThreadPlanStepUntil::Clear() {
83 TargetSP target_sp(m_thread.CalculateTarget());
84 if (target_sp) {
85 if (m_return_bp_id != LLDB_INVALID_BREAK_ID) {
86 target_sp->RemoveBreakpointByID(m_return_bp_id);
87 m_return_bp_id = LLDB_INVALID_BREAK_ID;
88 }
89
90 until_collection::iterator pos, end = m_until_points.end();
91 for (pos = m_until_points.begin(); pos != end; pos++) {
92 target_sp->RemoveBreakpointByID((*pos).second);
93 }
94 }
95 m_until_points.clear();
96 m_could_not_resolve_hw_bp = false;
97 }
98
99 void ThreadPlanStepUntil::GetDescription(Stream *s,
100 lldb::DescriptionLevel level) {
101 if (level == lldb::eDescriptionLevelBrief) {
102 s->Printf("step until");
103 if (m_stepped_out)
104 s->Printf(" - stepped out");
105 } else {
106 if (m_until_points.size() == 1)
107 s->Printf("Stepping from address 0x%" PRIx64 " until we reach 0x%" PRIx64
108 " using breakpoint %d",
109 (uint64_t)m_step_from_insn,
110 (uint64_t)(*m_until_points.begin()).first,
111 (*m_until_points.begin()).second);
112 else {
113 until_collection::iterator pos, end = m_until_points.end();
114 s->Printf("Stepping from address 0x%" PRIx64 " until we reach one of:",
115 (uint64_t)m_step_from_insn);
116 for (pos = m_until_points.begin(); pos != end; pos++) {
117 s->Printf("\n\t0x%" PRIx64 " (bp: %d)", (uint64_t)(*pos).first,
118 (*pos).second);
119 }
120 }
121 s->Printf(" stepped out address is 0x%" PRIx64 ".",
122 (uint64_t)m_return_addr);
123 }
124 }
125
126 bool ThreadPlanStepUntil::ValidatePlan(Stream *error) {
127 if (m_could_not_resolve_hw_bp) {
128 if (error)
129 error->PutCString(
130 "Could not create hardware breakpoint for thread plan.");
131 return false;
132 } else if (m_return_bp_id == LLDB_INVALID_BREAK_ID) {
133 if (error)
134 error->PutCString("Could not create return breakpoint.");
135 return false;
136 } else {
137 until_collection::iterator pos, end = m_until_points.end();
138 for (pos = m_until_points.begin(); pos != end; pos++) {
139 if (!LLDB_BREAK_ID_IS_VALID((*pos).second))
140 return false;
141 }
142 return true;
143 }
144 }
145
146 void ThreadPlanStepUntil::AnalyzeStop() {
147 if (m_ran_analyze)
148 return;
149
150 StopInfoSP stop_info_sp = GetPrivateStopInfo();
151 m_should_stop = true;
152 m_explains_stop = false;
153
154 if (stop_info_sp) {
155 StopReason reason = stop_info_sp->GetStopReason();
156
157 if (reason == eStopReasonBreakpoint) {
158 // If this is OUR breakpoint, we're fine, otherwise we don't know why
159 // this happened...
160 BreakpointSiteSP this_site =
161 m_thread.GetProcess()->GetBreakpointSiteList().FindByID(
162 stop_info_sp->GetValue());
163 if (!this_site) {
164 m_explains_stop = false;
165 return;
166 }
167
168 if (this_site->IsBreakpointAtThisSite(m_return_bp_id)) {
169 // If we are at our "step out" breakpoint, and the stack depth has
170 // shrunk, then this is indeed our stop. If the stack depth has grown,
171 // then we've hit our step out breakpoint recursively. If we are the
172 // only breakpoint at that location, then we do explain the stop, and
173 // we'll just continue. If there was another breakpoint here, then we
174 // don't explain the stop, but we won't mark ourselves Completed,
175 // because maybe that breakpoint will continue, and then we'll finish
176 // the "until".
177 bool done;
178 StackID cur_frame_zero_id;
179
180 done = (m_stack_id < cur_frame_zero_id);
181
182 if (done) {
183 m_stepped_out = true;
184 SetPlanComplete();
185 } else
186 m_should_stop = false;
187
188 if (this_site->GetNumberOfOwners() == 1)
189 m_explains_stop = true;
190 else
191 m_explains_stop = false;
192 return;
193 } else {
194 // Check if we've hit one of our "until" breakpoints.
195 until_collection::iterator pos, end = m_until_points.end();
196 for (pos = m_until_points.begin(); pos != end; pos++) {
197 if (this_site->IsBreakpointAtThisSite((*pos).second)) {
198 // If we're at the right stack depth, then we're done.
199
200 bool done;
201 StackID frame_zero_id =
202 m_thread.GetStackFrameAtIndex(0)->GetStackID();
203
204 if (frame_zero_id == m_stack_id)
205 done = true;
206 else if (frame_zero_id < m_stack_id)
207 done = false;
208 else {
209 StackFrameSP older_frame_sp = m_thread.GetStackFrameAtIndex(1);
210
211 // But if we can't even unwind one frame we should just get out
212 // of here & stop...
213 if (older_frame_sp) {
214 const SymbolContext &older_context =
215 older_frame_sp->GetSymbolContext(eSymbolContextEverything);
216 SymbolContext stack_context;
217 m_stack_id.GetSymbolContextScope()->CalculateSymbolContext(
218 &stack_context);
219
220 done = (older_context == stack_context);
221 } else
222 done = false;
223 }
224
225 if (done)
226 SetPlanComplete();
227 else
228 m_should_stop = false;
229
230 // Otherwise we've hit this breakpoint recursively. If we're the
231 // only breakpoint here, then we do explain the stop, and we'll
232 // continue. If not then we should let higher plans handle this
233 // stop.
234 if (this_site->GetNumberOfOwners() == 1)
235 m_explains_stop = true;
236 else {
237 m_should_stop = true;
238 m_explains_stop = false;
239 }
240 return;
241 }
242 }
243 }
244 // If we get here we haven't hit any of our breakpoints, so let the
245 // higher plans take care of the stop.
246 m_explains_stop = false;
247 return;
248 } else if (IsUsuallyUnexplainedStopReason(reason)) {
249 m_explains_stop = false;
250 } else {
251 m_explains_stop = true;
252 }
253 }
254 }
255
256 bool ThreadPlanStepUntil::DoPlanExplainsStop(Event *event_ptr) {
257 // We don't explain signals or breakpoints (breakpoints that handle stepping
258 // in or out will be handled by a child plan.
259 AnalyzeStop();
260 return m_explains_stop;
261 }
262
263 bool ThreadPlanStepUntil::ShouldStop(Event *event_ptr) {
264 // If we've told our self in ExplainsStop that we plan to continue, then do
265 // so here. Otherwise, as long as this thread has stopped for a reason, we
266 // will stop.
267
268 StopInfoSP stop_info_sp = GetPrivateStopInfo();
269 if (!stop_info_sp || stop_info_sp->GetStopReason() == eStopReasonNone)
270 return false;
271
272 AnalyzeStop();
273 return m_should_stop;
274 }
275
276 bool ThreadPlanStepUntil::StopOthers() { return m_stop_others; }
277
278 StateType ThreadPlanStepUntil::GetPlanRunState() { return eStateRunning; }
279
280 bool ThreadPlanStepUntil::DoWillResume(StateType resume_state,
281 bool current_plan) {
282 if (current_plan) {
283 TargetSP target_sp(m_thread.CalculateTarget());
284 if (target_sp) {
285 Breakpoint *return_bp =
286 target_sp->GetBreakpointByID(m_return_bp_id).get();
287 if (return_bp != nullptr)
288 return_bp->SetEnabled(true);
289
290 until_collection::iterator pos, end = m_until_points.end();
291 for (pos = m_until_points.begin(); pos != end; pos++) {
292 Breakpoint *until_bp =
293 target_sp->GetBreakpointByID((*pos).second).get();
294 if (until_bp != nullptr)
295 until_bp->SetEnabled(true);
296 }
297 }
298 }
299
300 m_should_stop = true;
301 m_ran_analyze = false;
302 m_explains_stop = false;
303 return true;
304 }
305
306 bool ThreadPlanStepUntil::WillStop() {
307 TargetSP target_sp(m_thread.CalculateTarget());
308 if (target_sp) {
309 Breakpoint *return_bp = target_sp->GetBreakpointByID(m_return_bp_id).get();
310 if (return_bp != nullptr)
311 return_bp->SetEnabled(false);
312
313 until_collection::iterator pos, end = m_until_points.end();
314 for (pos = m_until_points.begin(); pos != end; pos++) {
315 Breakpoint *until_bp = target_sp->GetBreakpointByID((*pos).second).get();
316 if (until_bp != nullptr)
317 until_bp->SetEnabled(false);
318 }
319 }
320 return true;
321 }
322
323 bool ThreadPlanStepUntil::MischiefManaged() {
324 // I'm letting "PlanExplainsStop" do all the work, and just reporting that
325 // here.
326 bool done = false;
327 if (IsPlanComplete()) {
328 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
329 LLDB_LOGF(log, "Completed step until plan.");
330
331 Clear();
332 done = true;
333 }
334 if (done)
335 ThreadPlan::MischiefManaged();
336
337 return done;
338 }