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