1//===-- ThreadPlanStepInRange.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/ThreadPlanStepInRange.h"
10#include "lldb/Core/Architecture.h"
11#include "lldb/Core/Module.h"
12#include "lldb/Symbol/Function.h"
13#include "lldb/Symbol/Symbol.h"
14#include "lldb/Target/Process.h"
15#include "lldb/Target/RegisterContext.h"
16#include "lldb/Target/SectionLoadList.h"
17#include "lldb/Target/Target.h"
18#include "lldb/Target/Thread.h"
19#include "lldb/Target/ThreadPlanStepOut.h"
20#include "lldb/Target/ThreadPlanStepThrough.h"
21#include "lldb/Utility/LLDBLog.h"
22#include "lldb/Utility/Log.h"
23#include "lldb/Utility/RegularExpression.h"
24#include "lldb/Utility/Stream.h"
25
26using namespace lldb;
27using namespace lldb_private;
28
29uint32_t ThreadPlanStepInRange::s_default_flag_values =
30 ThreadPlanShouldStopHere::eStepInAvoidNoDebug;
31
32// ThreadPlanStepInRange: Step through a stack range, either stepping over or
33// into based on the value of \a type.
34
35ThreadPlanStepInRange::ThreadPlanStepInRange(
36 Thread &thread, const AddressRange &range,
37 const SymbolContext &addr_context, const char *step_into_target,
38 lldb::RunMode stop_others, LazyBool step_in_avoids_code_without_debug_info,
39 LazyBool step_out_avoids_code_without_debug_info)
40 : ThreadPlanStepRange(ThreadPlan::eKindStepInRange,
41 "Step Range stepping in", thread, range, addr_context,
42 stop_others),
43 ThreadPlanShouldStopHere(this), m_step_past_prologue(true),
44 m_virtual_step(false), m_step_into_target(step_into_target) {
45 SetCallbacks();
46 SetFlagsToDefault();
47 SetupAvoidNoDebug(step_in_avoids_code_without_debug_info,
48 step_out_avoids_code_without_debug_info);
49}
50
51ThreadPlanStepInRange::~ThreadPlanStepInRange() = default;
52
53void ThreadPlanStepInRange::SetupAvoidNoDebug(
54 LazyBool step_in_avoids_code_without_debug_info,
55 LazyBool step_out_avoids_code_without_debug_info) {
56 bool avoid_nodebug = true;
57 Thread &thread = GetThread();
58 switch (step_in_avoids_code_without_debug_info) {
59 case eLazyBoolYes:
60 avoid_nodebug = true;
61 break;
62 case eLazyBoolNo:
63 avoid_nodebug = false;
64 break;
65 case eLazyBoolCalculate:
66 avoid_nodebug = thread.GetStepInAvoidsNoDebug();
67 break;
68 }
69 if (avoid_nodebug)
70 GetFlags().Set(ThreadPlanShouldStopHere::eStepInAvoidNoDebug);
71 else
72 GetFlags().Clear(mask: ThreadPlanShouldStopHere::eStepInAvoidNoDebug);
73
74 switch (step_out_avoids_code_without_debug_info) {
75 case eLazyBoolYes:
76 avoid_nodebug = true;
77 break;
78 case eLazyBoolNo:
79 avoid_nodebug = false;
80 break;
81 case eLazyBoolCalculate:
82 avoid_nodebug = thread.GetStepOutAvoidsNoDebug();
83 break;
84 }
85 if (avoid_nodebug)
86 GetFlags().Set(ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
87 else
88 GetFlags().Clear(mask: ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
89}
90
91void ThreadPlanStepInRange::GetDescription(Stream *s,
92 lldb::DescriptionLevel level) {
93
94 auto PrintFailureIfAny = [&]() {
95 if (m_status.Success())
96 return;
97 s->Printf(format: " failed (%s)", m_status.AsCString());
98 };
99
100 if (level == lldb::eDescriptionLevelBrief) {
101 s->Printf(format: "step in");
102 PrintFailureIfAny();
103 return;
104 }
105
106 s->Printf(format: "Stepping in");
107 bool printed_line_info = false;
108 if (m_addr_context.line_entry.IsValid()) {
109 s->Printf(format: " through line ");
110 m_addr_context.line_entry.DumpStopContext(s, show_fullpaths: false);
111 printed_line_info = true;
112 }
113
114 const char *step_into_target = m_step_into_target.AsCString();
115 if (step_into_target && step_into_target[0] != '\0')
116 s->Printf(format: " targeting %s", m_step_into_target.AsCString());
117
118 if (!printed_line_info || level == eDescriptionLevelVerbose) {
119 s->Printf(format: " using ranges:");
120 DumpRanges(s);
121 }
122
123 PrintFailureIfAny();
124
125 s->PutChar(ch: '.');
126}
127
128bool ThreadPlanStepInRange::ShouldStop(Event *event_ptr) {
129 Log *log = GetLog(mask: LLDBLog::Step);
130
131 if (log) {
132 StreamString s;
133 DumpAddress(s&: s.AsRawOstream(), addr: GetThread().GetRegisterContext()->GetPC(),
134 addr_size: GetTarget().GetArchitecture().GetAddressByteSize());
135 LLDB_LOGF(log, "ThreadPlanStepInRange reached %s.", s.GetData());
136 }
137
138 if (IsPlanComplete())
139 return true;
140
141 m_no_more_plans = false;
142 if (m_sub_plan_sp && m_sub_plan_sp->IsPlanComplete()) {
143 if (!m_sub_plan_sp->PlanSucceeded()) {
144 SetPlanComplete();
145 m_no_more_plans = true;
146 return true;
147 } else
148 m_sub_plan_sp.reset();
149 }
150
151 if (m_virtual_step) {
152 // If we've just completed a virtual step, all we need to do is check for a
153 // ShouldStopHere plan, and otherwise we're done.
154 // FIXME - This can be both a step in and a step out. Probably should
155 // record which in the m_virtual_step.
156 m_sub_plan_sp =
157 CheckShouldStopHereAndQueueStepOut(operation: eFrameCompareYounger, status&: m_status);
158 } else {
159 // Stepping through should be done running other threads in general, since
160 // we're setting a breakpoint and continuing. So only stop others if we
161 // are explicitly told to do so.
162
163 bool stop_others = (m_stop_others == lldb::eOnlyThisThread);
164
165 FrameComparison frame_order = CompareCurrentFrameToStartFrame();
166
167 Thread &thread = GetThread();
168 if (frame_order == eFrameCompareOlder ||
169 frame_order == eFrameCompareSameParent) {
170 // If we're in an older frame then we should stop.
171 //
172 // A caveat to this is if we think the frame is older but we're actually
173 // in a trampoline.
174 // I'm going to make the assumption that you wouldn't RETURN to a
175 // trampoline. So if we are in a trampoline we think the frame is older
176 // because the trampoline confused the backtracer.
177 m_sub_plan_sp = thread.QueueThreadPlanForStepThrough(
178 return_stack_id&: m_stack_id, abort_other_plans: false, stop_other_threads: stop_others, status&: m_status);
179 if (!m_sub_plan_sp) {
180 // Otherwise check the ShouldStopHere for step out:
181 m_sub_plan_sp =
182 CheckShouldStopHereAndQueueStepOut(operation: frame_order, status&: m_status);
183 if (log) {
184 if (m_sub_plan_sp)
185 LLDB_LOGF(log,
186 "ShouldStopHere found plan to step out of this frame.");
187 else
188 LLDB_LOGF(log, "ShouldStopHere no plan to step out of this frame.");
189 }
190 } else if (log) {
191 LLDB_LOGF(
192 log, "Thought I stepped out, but in fact arrived at a trampoline.");
193 }
194 } else if (frame_order == eFrameCompareEqual && InSymbol()) {
195 // If we are not in a place we should step through, we're done. One
196 // tricky bit here is that some stubs don't push a frame, so we have to
197 // check both the case of a frame that is younger, or the same as this
198 // frame. However, if the frame is the same, and we are still in the
199 // symbol we started in, the we don't need to do this. This first check
200 // isn't strictly necessary, but it is more efficient.
201
202 // If we're still in the range, keep going, either by running to the next
203 // branch breakpoint, or by stepping.
204 if (InRange()) {
205 SetNextBranchBreakpoint();
206 return false;
207 }
208
209 SetPlanComplete();
210 m_no_more_plans = true;
211 return true;
212 }
213
214 // If we get to this point, we're not going to use a previously set "next
215 // branch" breakpoint, so delete it:
216 ClearNextBranchBreakpoint();
217
218 // We may have set the plan up above in the FrameIsOlder section:
219
220 if (!m_sub_plan_sp)
221 m_sub_plan_sp = thread.QueueThreadPlanForStepThrough(
222 return_stack_id&: m_stack_id, abort_other_plans: false, stop_other_threads: stop_others, status&: m_status);
223
224 if (log) {
225 if (m_sub_plan_sp)
226 LLDB_LOGF(log, "Found a step through plan: %s",
227 m_sub_plan_sp->GetName());
228 else
229 LLDB_LOGF(log, "No step through plan found.");
230 }
231
232 // If not, give the "should_stop" callback a chance to push a plan to get
233 // us out of here. But only do that if we actually have stepped in.
234 if (!m_sub_plan_sp && frame_order == eFrameCompareYounger)
235 m_sub_plan_sp = CheckShouldStopHereAndQueueStepOut(operation: frame_order, status&: m_status);
236
237 // If we've stepped in and we are going to stop here, check to see if we
238 // were asked to run past the prologue, and if so do that.
239
240 if (!m_sub_plan_sp && frame_order == eFrameCompareYounger &&
241 m_step_past_prologue) {
242 lldb::StackFrameSP curr_frame = thread.GetStackFrameAtIndex(idx: 0);
243 if (curr_frame) {
244 size_t bytes_to_skip = 0;
245 lldb::addr_t curr_addr = thread.GetRegisterContext()->GetPC();
246 Address func_start_address;
247
248 SymbolContext sc = curr_frame->GetSymbolContext(resolve_scope: eSymbolContextFunction |
249 eSymbolContextSymbol);
250
251 if (sc.function) {
252 func_start_address = sc.function->GetAddressRange().GetBaseAddress();
253 if (curr_addr == func_start_address.GetLoadAddress(target: &GetTarget()))
254 bytes_to_skip = sc.function->GetPrologueByteSize();
255 } else if (sc.symbol) {
256 func_start_address = sc.symbol->GetAddress();
257 if (curr_addr == func_start_address.GetLoadAddress(target: &GetTarget()))
258 bytes_to_skip = sc.symbol->GetPrologueByteSize();
259 }
260
261 if (bytes_to_skip == 0 && sc.symbol) {
262 const Architecture *arch = GetTarget().GetArchitecturePlugin();
263 if (arch) {
264 Address curr_sec_addr;
265 GetTarget().GetSectionLoadList().ResolveLoadAddress(load_addr: curr_addr,
266 so_addr&: curr_sec_addr);
267 bytes_to_skip = arch->GetBytesToSkip(func&: *sc.symbol, curr_addr: curr_sec_addr);
268 }
269 }
270
271 if (bytes_to_skip != 0) {
272 func_start_address.Slide(offset: bytes_to_skip);
273 log = GetLog(mask: LLDBLog::Step);
274 LLDB_LOGF(log, "Pushing past prologue ");
275
276 m_sub_plan_sp = thread.QueueThreadPlanForRunToAddress(
277 abort_other_plans: false, target_addr&: func_start_address, stop_other_threads: true, status&: m_status);
278 }
279 }
280 }
281 }
282
283 if (!m_sub_plan_sp) {
284 m_no_more_plans = true;
285 SetPlanComplete();
286 return true;
287 } else {
288 m_no_more_plans = false;
289 m_sub_plan_sp->SetPrivate(true);
290 return false;
291 }
292}
293
294void ThreadPlanStepInRange::SetAvoidRegexp(const char *name) {
295 if (m_avoid_regexp_up)
296 *m_avoid_regexp_up = RegularExpression(name);
297 else
298 m_avoid_regexp_up = std::make_unique<RegularExpression>(args&: name);
299}
300
301void ThreadPlanStepInRange::SetDefaultFlagValue(uint32_t new_value) {
302 // TODO: Should we test this for sanity?
303 ThreadPlanStepInRange::s_default_flag_values = new_value;
304}
305
306bool ThreadPlanStepInRange::FrameMatchesAvoidCriteria() {
307 StackFrame *frame = GetThread().GetStackFrameAtIndex(idx: 0).get();
308
309 // Check the library list first, as that's cheapest:
310 bool libraries_say_avoid = false;
311
312 FileSpecList libraries_to_avoid(GetThread().GetLibrariesToAvoid());
313 size_t num_libraries = libraries_to_avoid.GetSize();
314 if (num_libraries > 0) {
315 SymbolContext sc(frame->GetSymbolContext(resolve_scope: eSymbolContextModule));
316 FileSpec frame_library(sc.module_sp->GetFileSpec());
317
318 if (frame_library) {
319 for (size_t i = 0; i < num_libraries; i++) {
320 const FileSpec &file_spec(libraries_to_avoid.GetFileSpecAtIndex(idx: i));
321 if (FileSpec::Match(pattern: file_spec, file: frame_library)) {
322 libraries_say_avoid = true;
323 break;
324 }
325 }
326 }
327 }
328 if (libraries_say_avoid)
329 return true;
330
331 const RegularExpression *avoid_regexp_to_use = m_avoid_regexp_up.get();
332 if (avoid_regexp_to_use == nullptr)
333 avoid_regexp_to_use = GetThread().GetSymbolsToAvoidRegexp();
334
335 if (avoid_regexp_to_use != nullptr) {
336 SymbolContext sc = frame->GetSymbolContext(
337 resolve_scope: eSymbolContextFunction | eSymbolContextBlock | eSymbolContextSymbol);
338 if (sc.symbol != nullptr) {
339 const char *frame_function_name =
340 sc.GetFunctionName(preference: Mangled::ePreferDemangledWithoutArguments)
341 .GetCString();
342 if (frame_function_name) {
343 bool return_value = avoid_regexp_to_use->Execute(string: frame_function_name);
344 if (return_value) {
345 LLDB_LOGF(GetLog(LLDBLog::Step),
346 "Stepping out of function \"%s\" because it matches the "
347 "avoid regexp \"%s\".",
348 frame_function_name,
349 avoid_regexp_to_use->GetText().str().c_str());
350 }
351 return return_value;
352 }
353 }
354 }
355 return false;
356}
357
358bool ThreadPlanStepInRange::DefaultShouldStopHereCallback(
359 ThreadPlan *current_plan, Flags &flags, FrameComparison operation,
360 Status &status, void *baton) {
361 bool should_stop_here = true;
362 StackFrame *frame = current_plan->GetThread().GetStackFrameAtIndex(idx: 0).get();
363 Log *log = GetLog(mask: LLDBLog::Step);
364
365 // First see if the ThreadPlanShouldStopHere default implementation thinks we
366 // should get out of here:
367 should_stop_here = ThreadPlanShouldStopHere::DefaultShouldStopHereCallback(
368 current_plan, flags, operation, status, baton);
369 if (!should_stop_here)
370 return false;
371
372 if (should_stop_here && current_plan->GetKind() == eKindStepInRange &&
373 operation == eFrameCompareYounger) {
374 ThreadPlanStepInRange *step_in_range_plan =
375 static_cast<ThreadPlanStepInRange *>(current_plan);
376 if (step_in_range_plan->m_step_into_target) {
377 SymbolContext sc = frame->GetSymbolContext(
378 resolve_scope: eSymbolContextFunction | eSymbolContextBlock | eSymbolContextSymbol);
379 if (sc.symbol != nullptr) {
380 // First try an exact match, since that's cheap with ConstStrings.
381 // Then do a strstr compare.
382 if (step_in_range_plan->m_step_into_target == sc.GetFunctionName()) {
383 should_stop_here = true;
384 } else {
385 const char *target_name =
386 step_in_range_plan->m_step_into_target.AsCString();
387 const char *function_name = sc.GetFunctionName().AsCString();
388
389 if (function_name == nullptr)
390 should_stop_here = false;
391 else if (strstr(haystack: function_name, needle: target_name) == nullptr)
392 should_stop_here = false;
393 }
394 if (log && !should_stop_here)
395 LLDB_LOGF(log,
396 "Stepping out of frame %s which did not match step into "
397 "target %s.",
398 sc.GetFunctionName().AsCString(),
399 step_in_range_plan->m_step_into_target.AsCString());
400 }
401 }
402
403 if (should_stop_here) {
404 ThreadPlanStepInRange *step_in_range_plan =
405 static_cast<ThreadPlanStepInRange *>(current_plan);
406 // Don't log the should_step_out here, it's easier to do it in
407 // FrameMatchesAvoidCriteria.
408 should_stop_here = !step_in_range_plan->FrameMatchesAvoidCriteria();
409 }
410 }
411
412 return should_stop_here;
413}
414
415bool ThreadPlanStepInRange::DoPlanExplainsStop(Event *event_ptr) {
416 // We always explain a stop. Either we've just done a single step, in which
417 // case we'll do our ordinary processing, or we stopped for some reason that
418 // isn't handled by our sub-plans, in which case we want to just stop right
419 // away. In general, we don't want to mark the plan as complete for
420 // unexplained stops. For instance, if you step in to some code with no debug
421 // info, so you step out and in the course of that hit a breakpoint, then you
422 // want to stop & show the user the breakpoint, but not unship the step in
423 // plan, since you still may want to complete that plan when you continue.
424 // This is particularly true when doing "step in to target function."
425 // stepping.
426 //
427 // The only variation is that if we are doing "step by running to next
428 // branch" in which case if we hit our branch breakpoint we don't set the
429 // plan to complete.
430
431 bool return_value = false;
432
433 if (m_virtual_step) {
434 return_value = true;
435 } else {
436 StopInfoSP stop_info_sp = GetPrivateStopInfo();
437 if (stop_info_sp) {
438 StopReason reason = stop_info_sp->GetStopReason();
439
440 if (reason == eStopReasonBreakpoint) {
441 if (NextRangeBreakpointExplainsStop(stop_info_sp)) {
442 return_value = true;
443 }
444 } else if (IsUsuallyUnexplainedStopReason(reason)) {
445 Log *log = GetLog(mask: LLDBLog::Step);
446 if (log)
447 log->PutCString(cstr: "ThreadPlanStepInRange got asked if it explains the "
448 "stop for some reason other than step.");
449 return_value = false;
450 } else {
451 return_value = true;
452 }
453 } else
454 return_value = true;
455 }
456
457 return return_value;
458}
459
460bool ThreadPlanStepInRange::DoWillResume(lldb::StateType resume_state,
461 bool current_plan) {
462 m_virtual_step = false;
463 if (resume_state == eStateStepping && current_plan) {
464 Thread &thread = GetThread();
465 // See if we are about to step over a virtual inlined call.
466 bool step_without_resume = thread.DecrementCurrentInlinedDepth();
467 if (step_without_resume) {
468 Log *log = GetLog(mask: LLDBLog::Step);
469 LLDB_LOGF(log,
470 "ThreadPlanStepInRange::DoWillResume: returning false, "
471 "inline_depth: %d",
472 thread.GetCurrentInlinedDepth());
473 SetStopInfo(StopInfo::CreateStopReasonToTrace(thread));
474
475 // FIXME: Maybe it would be better to create a InlineStep stop reason, but
476 // then
477 // the whole rest of the world would have to handle that stop reason.
478 m_virtual_step = true;
479 }
480 return !step_without_resume;
481 }
482 return true;
483}
484
485bool ThreadPlanStepInRange::IsVirtualStep() { return m_virtual_step; }
486

source code of lldb/source/Target/ThreadPlanStepInRange.cpp