1 //===-- ThreadPlanStepOverRange.cpp -----------------------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "lldb/Target/ThreadPlanStepOverRange.h"
11 #include "lldb/Symbol/Block.h"
12 #include "lldb/Symbol/CompileUnit.h"
13 #include "lldb/Symbol/Function.h"
14 #include "lldb/Symbol/LineTable.h"
15 #include "lldb/Target/Process.h"
16 #include "lldb/Target/RegisterContext.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/Log.h"
22 #include "lldb/Utility/Stream.h"
23
24 using namespace lldb_private;
25 using namespace lldb;
26
27 uint32_t ThreadPlanStepOverRange::s_default_flag_values = 0;
28
29 //----------------------------------------------------------------------
30 // ThreadPlanStepOverRange: Step through a stack range, either stepping over or
31 // into based on the value of \a type.
32 //----------------------------------------------------------------------
33
ThreadPlanStepOverRange(Thread & thread,const AddressRange & range,const SymbolContext & addr_context,lldb::RunMode stop_others,LazyBool step_out_avoids_code_without_debug_info)34 ThreadPlanStepOverRange::ThreadPlanStepOverRange(
35 Thread &thread, const AddressRange &range,
36 const SymbolContext &addr_context, lldb::RunMode stop_others,
37 LazyBool step_out_avoids_code_without_debug_info)
38 : ThreadPlanStepRange(ThreadPlan::eKindStepOverRange,
39 "Step range stepping over", thread, range,
40 addr_context, stop_others),
41 ThreadPlanShouldStopHere(this), m_first_resume(true) {
42 SetFlagsToDefault();
43 SetupAvoidNoDebug(step_out_avoids_code_without_debug_info);
44 }
45
46 ThreadPlanStepOverRange::~ThreadPlanStepOverRange() = default;
47
GetDescription(Stream * s,lldb::DescriptionLevel level)48 void ThreadPlanStepOverRange::GetDescription(Stream *s,
49 lldb::DescriptionLevel level) {
50 auto PrintFailureIfAny = [&]() {
51 if (m_status.Success())
52 return;
53 s->Printf(" failed (%s)", m_status.AsCString());
54 };
55
56 if (level == lldb::eDescriptionLevelBrief) {
57 s->Printf("step over");
58 PrintFailureIfAny();
59 return;
60 }
61
62 s->Printf("Stepping over");
63 bool printed_line_info = false;
64 if (m_addr_context.line_entry.IsValid()) {
65 s->Printf(" line ");
66 m_addr_context.line_entry.DumpStopContext(s, false);
67 printed_line_info = true;
68 }
69
70 if (!printed_line_info || level == eDescriptionLevelVerbose) {
71 s->Printf(" using ranges: ");
72 DumpRanges(s);
73 }
74
75 PrintFailureIfAny();
76
77 s->PutChar('.');
78 }
79
SetupAvoidNoDebug(LazyBool step_out_avoids_code_without_debug_info)80 void ThreadPlanStepOverRange::SetupAvoidNoDebug(
81 LazyBool step_out_avoids_code_without_debug_info) {
82 bool avoid_nodebug = true;
83 switch (step_out_avoids_code_without_debug_info) {
84 case eLazyBoolYes:
85 avoid_nodebug = true;
86 break;
87 case eLazyBoolNo:
88 avoid_nodebug = false;
89 break;
90 case eLazyBoolCalculate:
91 avoid_nodebug = m_thread.GetStepOutAvoidsNoDebug();
92 break;
93 }
94 if (avoid_nodebug)
95 GetFlags().Set(ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
96 else
97 GetFlags().Clear(ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
98 // Step Over plans should always avoid no-debug on step in. Seems like you
99 // shouldn't have to say this, but a tail call looks more like a step in that
100 // a step out, so we want to catch this case.
101 GetFlags().Set(ThreadPlanShouldStopHere::eStepInAvoidNoDebug);
102 }
103
IsEquivalentContext(const SymbolContext & context)104 bool ThreadPlanStepOverRange::IsEquivalentContext(
105 const SymbolContext &context) {
106 // Match as much as is specified in the m_addr_context: This is a fairly
107 // loose sanity check. Note, sometimes the target doesn't get filled in so I
108 // left out the target check. And sometimes the module comes in as the .o
109 // file from the inlined range, so I left that out too...
110 if (m_addr_context.comp_unit) {
111 if (m_addr_context.comp_unit != context.comp_unit)
112 return false;
113 if (m_addr_context.function) {
114 if (m_addr_context.function != context.function)
115 return false;
116 // It is okay to return to a different block of a straight function, we
117 // only have to be more careful if returning from one inlined block to
118 // another.
119 if (m_addr_context.block->GetInlinedFunctionInfo() == nullptr &&
120 context.block->GetInlinedFunctionInfo() == nullptr)
121 return true;
122 return m_addr_context.block == context.block;
123 }
124 }
125 // Fall back to symbol if we have no decision from comp_unit/function/block.
126 return m_addr_context.symbol && m_addr_context.symbol == context.symbol;
127 }
128
ShouldStop(Event * event_ptr)129 bool ThreadPlanStepOverRange::ShouldStop(Event *event_ptr) {
130 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
131
132 if (log) {
133 StreamString s;
134 s.Address(
135 m_thread.GetRegisterContext()->GetPC(),
136 m_thread.CalculateTarget()->GetArchitecture().GetAddressByteSize());
137 log->Printf("ThreadPlanStepOverRange reached %s.", s.GetData());
138 }
139
140 // If we're out of the range but in the same frame or in our caller's frame
141 // then we should stop. When stepping out we only stop others if we are
142 // forcing running one thread.
143 bool stop_others = (m_stop_others == lldb::eOnlyThisThread);
144 ThreadPlanSP new_plan_sp;
145 FrameComparison frame_order = CompareCurrentFrameToStartFrame();
146
147 if (frame_order == eFrameCompareOlder) {
148 // If we're in an older frame then we should stop.
149 //
150 // A caveat to this is if we think the frame is older but we're actually in
151 // a trampoline.
152 // I'm going to make the assumption that you wouldn't RETURN to a
153 // trampoline. So if we are in a trampoline we think the frame is older
154 // because the trampoline confused the backtracer. As below, we step
155 // through first, and then try to figure out how to get back out again.
156
157 new_plan_sp = m_thread.QueueThreadPlanForStepThrough(m_stack_id, false,
158 stop_others, m_status);
159
160 if (new_plan_sp && log)
161 log->Printf(
162 "Thought I stepped out, but in fact arrived at a trampoline.");
163 } else if (frame_order == eFrameCompareYounger) {
164 // Make sure we really are in a new frame. Do that by unwinding and seeing
165 // if the start function really is our start function...
166 for (uint32_t i = 1;; ++i) {
167 StackFrameSP older_frame_sp = m_thread.GetStackFrameAtIndex(i);
168 if (!older_frame_sp) {
169 // We can't unwind the next frame we should just get out of here &
170 // stop...
171 break;
172 }
173
174 const SymbolContext &older_context =
175 older_frame_sp->GetSymbolContext(eSymbolContextEverything);
176 if (IsEquivalentContext(older_context)) {
177 new_plan_sp = m_thread.QueueThreadPlanForStepOutNoShouldStop(
178 false, nullptr, true, stop_others, eVoteNo, eVoteNoOpinion, 0,
179 m_status, true);
180 break;
181 } else {
182 new_plan_sp = m_thread.QueueThreadPlanForStepThrough(
183 m_stack_id, false, stop_others, m_status);
184 // If we found a way through, then we should stop recursing.
185 if (new_plan_sp)
186 break;
187 }
188 }
189 } else {
190 // If we're still in the range, keep going.
191 if (InRange()) {
192 SetNextBranchBreakpoint();
193 return false;
194 }
195
196 if (!InSymbol()) {
197 // This one is a little tricky. Sometimes we may be in a stub or
198 // something similar, in which case we need to get out of there. But if
199 // we are in a stub then it's likely going to be hard to get out from
200 // here. It is probably easiest to step into the stub, and then it will
201 // be straight-forward to step out.
202 new_plan_sp = m_thread.QueueThreadPlanForStepThrough(
203 m_stack_id, false, stop_others, m_status);
204 } else {
205 // The current clang (at least through 424) doesn't always get the
206 // address range for the DW_TAG_inlined_subroutines right, so that when
207 // you leave the inlined range the line table says you are still in the
208 // source file of the inlining function. This is bad, because now you
209 // are missing the stack frame for the function containing the inlining,
210 // and if you sensibly do "finish" to get out of this function you will
211 // instead exit the containing function. To work around this, we check
212 // whether we are still in the source file we started in, and if not
213 // assume it is an error, and push a plan to get us out of this line and
214 // back to the containing file.
215
216 if (m_addr_context.line_entry.IsValid()) {
217 SymbolContext sc;
218 StackFrameSP frame_sp = m_thread.GetStackFrameAtIndex(0);
219 sc = frame_sp->GetSymbolContext(eSymbolContextEverything);
220 if (sc.line_entry.IsValid()) {
221 if (sc.line_entry.original_file !=
222 m_addr_context.line_entry.original_file &&
223 sc.comp_unit == m_addr_context.comp_unit &&
224 sc.function == m_addr_context.function) {
225 // Okay, find the next occurrence of this file in the line table:
226 LineTable *line_table = m_addr_context.comp_unit->GetLineTable();
227 if (line_table) {
228 Address cur_address = frame_sp->GetFrameCodeAddress();
229 uint32_t entry_idx;
230 LineEntry line_entry;
231 if (line_table->FindLineEntryByAddress(cur_address, line_entry,
232 &entry_idx)) {
233 LineEntry next_line_entry;
234 bool step_past_remaining_inline = false;
235 if (entry_idx > 0) {
236 // We require the previous line entry and the current line
237 // entry come from the same file. The other requirement is
238 // that the previous line table entry be part of an inlined
239 // block, we don't want to step past cases where people have
240 // inlined some code fragment by using #include <source-
241 // fragment.c> directly.
242 LineEntry prev_line_entry;
243 if (line_table->GetLineEntryAtIndex(entry_idx - 1,
244 prev_line_entry) &&
245 prev_line_entry.original_file ==
246 line_entry.original_file) {
247 SymbolContext prev_sc;
248 Address prev_address =
249 prev_line_entry.range.GetBaseAddress();
250 prev_address.CalculateSymbolContext(&prev_sc);
251 if (prev_sc.block) {
252 Block *inlined_block =
253 prev_sc.block->GetContainingInlinedBlock();
254 if (inlined_block) {
255 AddressRange inline_range;
256 inlined_block->GetRangeContainingAddress(prev_address,
257 inline_range);
258 if (!inline_range.ContainsFileAddress(cur_address)) {
259
260 step_past_remaining_inline = true;
261 }
262 }
263 }
264 }
265 }
266
267 if (step_past_remaining_inline) {
268 uint32_t look_ahead_step = 1;
269 while (line_table->GetLineEntryAtIndex(
270 entry_idx + look_ahead_step, next_line_entry)) {
271 // Make sure we haven't wandered out of the function we
272 // started from...
273 Address next_line_address =
274 next_line_entry.range.GetBaseAddress();
275 Function *next_line_function =
276 next_line_address.CalculateSymbolContextFunction();
277 if (next_line_function != m_addr_context.function)
278 break;
279
280 if (next_line_entry.original_file ==
281 m_addr_context.line_entry.original_file) {
282 const bool abort_other_plans = false;
283 const RunMode stop_other_threads = RunMode::eAllThreads;
284 lldb::addr_t cur_pc = m_thread.GetStackFrameAtIndex(0)
285 ->GetRegisterContext()
286 ->GetPC();
287 AddressRange step_range(
288 cur_pc,
289 next_line_address.GetLoadAddress(&GetTarget()) -
290 cur_pc);
291
292 new_plan_sp = m_thread.QueueThreadPlanForStepOverRange(
293 abort_other_plans, step_range, sc, stop_other_threads,
294 m_status);
295 break;
296 }
297 look_ahead_step++;
298 }
299 }
300 }
301 }
302 }
303 }
304 }
305 }
306 }
307
308 // If we get to this point, we're not going to use a previously set "next
309 // branch" breakpoint, so delete it:
310 ClearNextBranchBreakpoint();
311
312 // If we haven't figured out something to do yet, then ask the ShouldStopHere
313 // callback:
314 if (!new_plan_sp) {
315 new_plan_sp = CheckShouldStopHereAndQueueStepOut(frame_order, m_status);
316 }
317
318 if (!new_plan_sp)
319 m_no_more_plans = true;
320 else {
321 // Any new plan will be an implementation plan, so mark it private:
322 new_plan_sp->SetPrivate(true);
323 m_no_more_plans = false;
324 }
325
326 if (!new_plan_sp) {
327 // For efficiencies sake, we know we're done here so we don't have to do
328 // this calculation again in MischiefManaged.
329 SetPlanComplete(m_status.Success());
330 return true;
331 } else
332 return false;
333 }
334
DoPlanExplainsStop(Event * event_ptr)335 bool ThreadPlanStepOverRange::DoPlanExplainsStop(Event *event_ptr) {
336 // For crashes, breakpoint hits, signals, etc, let the base plan (or some
337 // plan above us) handle the stop. That way the user can see the stop, step
338 // around, and then when they are done, continue and have their step
339 // complete. The exception is if we've hit our "run to next branch"
340 // breakpoint. Note, unlike the step in range plan, we don't mark ourselves
341 // complete if we hit an unexplained breakpoint/crash.
342
343 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
344 StopInfoSP stop_info_sp = GetPrivateStopInfo();
345 bool return_value;
346
347 if (stop_info_sp) {
348 StopReason reason = stop_info_sp->GetStopReason();
349
350 if (reason == eStopReasonTrace) {
351 return_value = true;
352 } else if (reason == eStopReasonBreakpoint) {
353 return_value = NextRangeBreakpointExplainsStop(stop_info_sp);
354 } else {
355 if (log)
356 log->PutCString("ThreadPlanStepInRange got asked if it explains the "
357 "stop for some reason other than step.");
358 return_value = false;
359 }
360 } else
361 return_value = true;
362
363 return return_value;
364 }
365
DoWillResume(lldb::StateType resume_state,bool current_plan)366 bool ThreadPlanStepOverRange::DoWillResume(lldb::StateType resume_state,
367 bool current_plan) {
368 if (resume_state != eStateSuspended && m_first_resume) {
369 m_first_resume = false;
370 if (resume_state == eStateStepping && current_plan) {
371 // See if we are about to step over an inlined call in the middle of the
372 // inlined stack, if so figure out its extents and reset our range to
373 // step over that.
374 bool in_inlined_stack = m_thread.DecrementCurrentInlinedDepth();
375 if (in_inlined_stack) {
376 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
377 if (log)
378 log->Printf("ThreadPlanStepInRange::DoWillResume: adjusting range to "
379 "the frame at inlined depth %d.",
380 m_thread.GetCurrentInlinedDepth());
381 StackFrameSP stack_sp = m_thread.GetStackFrameAtIndex(0);
382 if (stack_sp) {
383 Block *frame_block = stack_sp->GetFrameBlock();
384 lldb::addr_t curr_pc = m_thread.GetRegisterContext()->GetPC();
385 AddressRange my_range;
386 if (frame_block->GetRangeContainingLoadAddress(
387 curr_pc, m_thread.GetProcess()->GetTarget(), my_range)) {
388 m_address_ranges.clear();
389 m_address_ranges.push_back(my_range);
390 if (log) {
391 StreamString s;
392 const InlineFunctionInfo *inline_info =
393 frame_block->GetInlinedFunctionInfo();
394 const char *name;
395 if (inline_info)
396 name =
397 inline_info
398 ->GetName(frame_block->CalculateSymbolContextFunction()
399 ->GetLanguage())
400 .AsCString();
401 else
402 name = "<unknown-notinlined>";
403
404 s.Printf(
405 "Stepping over inlined function \"%s\" in inlined stack: ",
406 name);
407 DumpRanges(&s);
408 log->PutString(s.GetString());
409 }
410 }
411 }
412 }
413 }
414 }
415
416 return true;
417 }
418