lldb/source/Target/ThreadPlanStepInRange.cpp

   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
  26 using namespace lldb;
  27 using namespace lldb_private;
  28
  29 uint32_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
  35 ThreadPlanStepInRange::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(eLazyBoolCalculate), 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
  51 ThreadPlanStepInRange::~ThreadPlanStepInRange() = default;
  52
  53 void 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(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(ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
  89 }
  90
  91 void ThreadPlanStepInRange::GetDescription(Stream *s,
  92                                            lldb::DescriptionLevel level) {
  93
  94   auto PrintFailureIfAny = [&]() {
  95     if (m_status.Success())
  96       return;
  97     s->Printf(" failed (%s)", m_status.AsCString());
  98   };
  99
 100   if (level == lldb::eDescriptionLevelBrief) {
 101     s->Printf("step in");
 102     PrintFailureIfAny();
 103     return;
 104   }
 105
 106   s->Printf("Stepping in");
 107   bool printed_line_info = false;
 108   if (m_addr_context.line_entry.IsValid()) {
 109     s->Printf(" through line ");
 110     m_addr_context.line_entry.DumpStopContext(s, 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(" targeting %s", m_step_into_target.AsCString());
 117
 118   if (!printed_line_info || level == eDescriptionLevelVerbose) {
 119     s->Printf(" using ranges:");
 120     DumpRanges(s);
 121   }
 122
 123   PrintFailureIfAny();
 124
 125   s->PutChar('.');
 126 }
 127
 128 bool ThreadPlanStepInRange::ShouldStop(Event *event_ptr) {
 129   Log *log = GetLog(LLDBLog::Step);
 130
 131   if (log) {
 132     StreamString s;
 133     DumpAddress(s.AsRawOstream(), GetThread().GetRegisterContext()->GetPC(),
 134                 GetTarget().GetArchitecture().GetAddressByteSize());
 135     LLDB_LOGF(log, "ThreadPlanStepInRange reached %s.", s.GetData());
 136   }
 137   ClearNextBranchBreakpointExplainedStop();
 138
 139   if (IsPlanComplete())
 140     return true;
 141
 142   m_no_more_plans = false;
 143   if (m_sub_plan_sp && m_sub_plan_sp->IsPlanComplete()) {
 144     if (!m_sub_plan_sp->PlanSucceeded()) {
 145       SetPlanComplete();
 146       m_no_more_plans = true;
 147       return true;
 148     } else
 149       m_sub_plan_sp.reset();
 150   }
 151
 152   if (m_virtual_step == eLazyBoolYes) {
 153     // If we've just completed a virtual step, all we need to do is check for a
 154     // ShouldStopHere plan, and otherwise we're done.
 155     // FIXME - This can be both a step in and a step out.  Probably should
 156     // record which in the m_virtual_step.
 157     m_sub_plan_sp =
 158         CheckShouldStopHereAndQueueStepOut(eFrameCompareYounger, m_status);
 159   } else {
 160     // Stepping through should be done running other threads in general, since
 161     // we're setting a breakpoint and continuing.  So only stop others if we
 162     // are explicitly told to do so.
 163
 164     bool stop_others = (m_stop_others == lldb::eOnlyThisThread);
 165
 166     FrameComparison frame_order = CompareCurrentFrameToStartFrame();
 167
 168     Thread &thread = GetThread();
 169     if (frame_order == eFrameCompareOlder ||
 170         frame_order == eFrameCompareSameParent) {
 171       // If we're in an older frame then we should stop.
 172       //
 173       // A caveat to this is if we think the frame is older but we're actually
 174       // in a trampoline.
 175       // I'm going to make the assumption that you wouldn't RETURN to a
 176       // trampoline.  So if we are in a trampoline we think the frame is older
 177       // because the trampoline confused the backtracer.
 178       m_sub_plan_sp = thread.QueueThreadPlanForStepThrough(
 179           m_stack_id, false, stop_others, m_status);
 180       if (!m_sub_plan_sp) {
 181         // Otherwise check the ShouldStopHere for step out:
 182         m_sub_plan_sp =
 183             CheckShouldStopHereAndQueueStepOut(frame_order, m_status);
 184         if (log) {
 185           if (m_sub_plan_sp)
 186             LLDB_LOGF(log,
 187                       "ShouldStopHere found plan to step out of this frame.");
 188           else
 189             LLDB_LOGF(log, "ShouldStopHere no plan to step out of this frame.");
 190         }
 191       } else if (log) {
 192         LLDB_LOGF(
 193             log, "Thought I stepped out, but in fact arrived at a trampoline.");
 194       }
 195     } else if (frame_order == eFrameCompareEqual && InSymbol()) {
 196       // If we are not in a place we should step through, we're done. One
 197       // tricky bit here is that some stubs don't push a frame, so we have to
 198       // check both the case of a frame that is younger, or the same as this
 199       // frame. However, if the frame is the same, and we are still in the
 200       // symbol we started in, the we don't need to do this.  This first check
 201       // isn't strictly necessary, but it is more efficient.
 202
 203       // If we're still in the range, keep going, either by running to the next
 204       // branch breakpoint, or by stepping.
 205       if (InRange()) {
 206         SetNextBranchBreakpoint();
 207         return false;
 208       }
 209
 210       SetPlanComplete();
 211       m_no_more_plans = true;
 212       return true;
 213     }
 214
 215     // If we get to this point, we're not going to use a previously set "next
 216     // branch" breakpoint, so delete it:
 217     ClearNextBranchBreakpoint();
 218
 219     // We may have set the plan up above in the FrameIsOlder section:
 220
 221     if (!m_sub_plan_sp)
 222       m_sub_plan_sp = thread.QueueThreadPlanForStepThrough(
 223           m_stack_id, false, stop_others, m_status);
 224
 225     if (log) {
 226       if (m_sub_plan_sp)
 227         LLDB_LOGF(log, "Found a step through plan: %s",
 228                   m_sub_plan_sp->GetName());
 229       else
 230         LLDB_LOGF(log, "No step through plan found.");
 231     }
 232
 233     // If not, give the "should_stop" callback a chance to push a plan to get
 234     // us out of here. But only do that if we actually have stepped in.
 235     if (!m_sub_plan_sp && frame_order == eFrameCompareYounger)
 236       m_sub_plan_sp = CheckShouldStopHereAndQueueStepOut(frame_order, m_status);
 237
 238     // If we've stepped in and we are going to stop here, check to see if we
 239     // were asked to run past the prologue, and if so do that.
 240
 241     if (!m_sub_plan_sp && frame_order == eFrameCompareYounger &&
 242         m_step_past_prologue) {
 243       lldb::StackFrameSP curr_frame = thread.GetStackFrameAtIndex(0);
 244       if (curr_frame) {
 245         size_t bytes_to_skip = 0;
 246         lldb::addr_t curr_addr = thread.GetRegisterContext()->GetPC();
 247         Address func_start_address;
 248
 249         SymbolContext sc = curr_frame->GetSymbolContext(eSymbolContextFunction |
 250                                                         eSymbolContextSymbol);
 251
 252         if (sc.function) {
 253           func_start_address = sc.function->GetAddressRange().GetBaseAddress();
 254           if (curr_addr == func_start_address.GetLoadAddress(&GetTarget()))
 255             bytes_to_skip = sc.function->GetPrologueByteSize();
 256         } else if (sc.symbol) {
 257           func_start_address = sc.symbol->GetAddress();
 258           if (curr_addr == func_start_address.GetLoadAddress(&GetTarget()))
 259             bytes_to_skip = sc.symbol->GetPrologueByteSize();
 260         }
 261
 262         if (bytes_to_skip == 0 && sc.symbol) {
 263           const Architecture *arch = GetTarget().GetArchitecturePlugin();
 264           if (arch) {
 265             Address curr_sec_addr;
 266             GetTarget().GetSectionLoadList().ResolveLoadAddress(curr_addr,
 267                                                                 curr_sec_addr);
 268             bytes_to_skip = arch->GetBytesToSkip(*sc.symbol, curr_sec_addr);
 269           }
 270         }
 271
 272         if (bytes_to_skip != 0) {
 273           func_start_address.Slide(bytes_to_skip);
 274           log = GetLog(LLDBLog::Step);
 275           LLDB_LOGF(log, "Pushing past prologue ");
 276
 277           m_sub_plan_sp = thread.QueueThreadPlanForRunToAddress(
 278               false, func_start_address, true, m_status);
 279         }
 280       }
 281     }
 282   }
 283
 284   if (!m_sub_plan_sp) {
 285     m_no_more_plans = true;
 286     SetPlanComplete();
 287     return true;
 288   } else {
 289     m_no_more_plans = false;
 290     m_sub_plan_sp->SetPrivate(true);
 291     return false;
 292   }
 293 }
 294
 295 void ThreadPlanStepInRange::SetAvoidRegexp(const char *name) {
 296   if (m_avoid_regexp_up)
 297     *m_avoid_regexp_up = RegularExpression(name);
 298   else
 299     m_avoid_regexp_up = std::make_unique<RegularExpression>(name);
 300 }
 301
 302 void ThreadPlanStepInRange::SetDefaultFlagValue(uint32_t new_value) {
 303   // TODO: Should we test this for sanity?
 304   ThreadPlanStepInRange::s_default_flag_values = new_value;
 305 }
 306
 307 bool ThreadPlanStepInRange::FrameMatchesAvoidCriteria() {
 308   StackFrame *frame = GetThread().GetStackFrameAtIndex(0).get();
 309
 310   // Check the library list first, as that's cheapest:
 311   bool libraries_say_avoid = false;
 312
 313   FileSpecList libraries_to_avoid(GetThread().GetLibrariesToAvoid());
 314   size_t num_libraries = libraries_to_avoid.GetSize();
 315   if (num_libraries > 0) {
 316     SymbolContext sc(frame->GetSymbolContext(eSymbolContextModule));
 317     FileSpec frame_library(sc.module_sp->GetFileSpec());
 318
 319     if (frame_library) {
 320       for (size_t i = 0; i < num_libraries; i++) {
 321         const FileSpec &file_spec(libraries_to_avoid.GetFileSpecAtIndex(i));
 322         if (FileSpec::Match(file_spec, frame_library)) {
 323           libraries_say_avoid = true;
 324           break;
 325         }
 326       }
 327     }
 328   }
 329   if (libraries_say_avoid)
 330     return true;
 331
 332   const RegularExpression *avoid_regexp_to_use = m_avoid_regexp_up.get();
 333   if (avoid_regexp_to_use == nullptr)
 334     avoid_regexp_to_use = GetThread().GetSymbolsToAvoidRegexp();
 335
 336   if (avoid_regexp_to_use != nullptr) {
 337     SymbolContext sc = frame->GetSymbolContext(
 338         eSymbolContextFunction | eSymbolContextBlock | eSymbolContextSymbol);
 339     if (sc.symbol != nullptr) {
 340       const char *frame_function_name =
 341           sc.GetFunctionName(Mangled::ePreferDemangledWithoutArguments)
 342               .GetCString();
 343       if (frame_function_name) {
 344         bool return_value = avoid_regexp_to_use->Execute(frame_function_name);
 345         if (return_value) {
 346           LLDB_LOGF(GetLog(LLDBLog::Step),
 347                     "Stepping out of function \"%s\" because it matches the "
 348                     "avoid regexp \"%s\".",
 349                     frame_function_name,
 350                     avoid_regexp_to_use->GetText().str().c_str());
 351         }
 352         return return_value;
 353       }
 354     }
 355   }
 356   return false;
 357 }
 358
 359 bool ThreadPlanStepInRange::DefaultShouldStopHereCallback(
 360     ThreadPlan *current_plan, Flags &flags, FrameComparison operation,
 361     Status &status, void *baton) {
 362   bool should_stop_here = true;
 363   StackFrame *frame = current_plan->GetThread().GetStackFrameAtIndex(0).get();
 364   Log *log = GetLog(LLDBLog::Step);
 365
 366   // First see if the ThreadPlanShouldStopHere default implementation thinks we
 367   // should get out of here:
 368   should_stop_here = ThreadPlanShouldStopHere::DefaultShouldStopHereCallback(
 369       current_plan, flags, operation, status, baton);
 370   if (!should_stop_here)
 371     return false;
 372
 373   if (should_stop_here && current_plan->GetKind() == eKindStepInRange &&
 374       operation == eFrameCompareYounger) {
 375     ThreadPlanStepInRange *step_in_range_plan =
 376         static_cast<ThreadPlanStepInRange *>(current_plan);
 377     if (step_in_range_plan->m_step_into_target) {
 378       SymbolContext sc = frame->GetSymbolContext(
 379           eSymbolContextFunction | eSymbolContextBlock | eSymbolContextSymbol);
 380       if (sc.symbol != nullptr) {
 381         // First try an exact match, since that's cheap with ConstStrings.
 382         // Then do a strstr compare.
 383         if (step_in_range_plan->m_step_into_target == sc.GetFunctionName()) {
 384           should_stop_here = true;
 385         } else {
 386           const char *target_name =
 387               step_in_range_plan->m_step_into_target.AsCString();
 388           const char *function_name = sc.GetFunctionName().AsCString();
 389
 390           if (function_name == nullptr)
 391             should_stop_here = false;
 392           else if (strstr(function_name, target_name) == nullptr)
 393             should_stop_here = false;
 394         }
 395         if (log && !should_stop_here)
 396           LLDB_LOGF(log,
 397                     "Stepping out of frame %s which did not match step into "
 398                     "target %s.",
 399                     sc.GetFunctionName().AsCString(),
 400                     step_in_range_plan->m_step_into_target.AsCString());
 401       }
 402     }
 403
 404     if (should_stop_here) {
 405       ThreadPlanStepInRange *step_in_range_plan =
 406           static_cast<ThreadPlanStepInRange *>(current_plan);
 407       // Don't log the should_step_out here, it's easier to do it in
 408       // FrameMatchesAvoidCriteria.
 409       should_stop_here = !step_in_range_plan->FrameMatchesAvoidCriteria();
 410     }
 411   }
 412
 413   return should_stop_here;
 414 }
 415
 416 bool ThreadPlanStepInRange::DoPlanExplainsStop(Event *event_ptr) {
 417   // We always explain a stop.  Either we've just done a single step, in which
 418   // case we'll do our ordinary processing, or we stopped for some reason that
 419   // isn't handled by our sub-plans, in which case we want to just stop right
 420   // away. In general, we don't want to mark the plan as complete for
 421   // unexplained stops. For instance, if you step in to some code with no debug
 422   // info, so you step out and in the course of that hit a breakpoint, then you
 423   // want to stop & show the user the breakpoint, but not unship the step in
 424   // plan, since you still may want to complete that plan when you continue.
 425   // This is particularly true when doing "step in to target function."
 426   // stepping.
 427   //
 428   // The only variation is that if we are doing "step by running to next
 429   // branch" in which case if we hit our branch breakpoint we don't set the
 430   // plan to complete.
 431
 432   bool return_value = false;
 433
 434   if (m_virtual_step == eLazyBoolYes) {
 435     return_value = true;
 436   } else {
 437     StopInfoSP stop_info_sp = GetPrivateStopInfo();
 438     if (stop_info_sp) {
 439       StopReason reason = stop_info_sp->GetStopReason();
 440
 441       if (reason == eStopReasonBreakpoint) {
 442         if (NextRangeBreakpointExplainsStop(stop_info_sp)) {
 443           return_value = true;
 444         }
 445       } else if (IsUsuallyUnexplainedStopReason(reason)) {
 446         Log *log = GetLog(LLDBLog::Step);
 447         if (log)
 448           log->PutCString("ThreadPlanStepInRange got asked if it explains the "
 449                           "stop for some reason other than step.");
 450         return_value = false;
 451       } else {
 452         return_value = true;
 453       }
 454     } else
 455       return_value = true;
 456   }
 457
 458   return return_value;
 459 }
 460
 461 bool ThreadPlanStepInRange::DoWillResume(lldb::StateType resume_state,
 462                                          bool current_plan) {
 463   m_virtual_step = eLazyBoolCalculate;
 464   if (resume_state == eStateStepping && current_plan) {
 465     Thread &thread = GetThread();
 466     // See if we are about to step over a virtual inlined call.
 467     // But if we already know we're virtual stepping, don't decrement the
 468     // inlined depth again...
 469
 470     bool step_without_resume = thread.DecrementCurrentInlinedDepth();
 471     if (step_without_resume) {
 472       Log *log = GetLog(LLDBLog::Step);
 473       LLDB_LOGF(log,
 474                 "ThreadPlanStepInRange::DoWillResume: returning false, "
 475                 "inline_depth: %d",
 476                 thread.GetCurrentInlinedDepth());
 477       SetStopInfo(StopInfo::CreateStopReasonToTrace(thread));
 478
 479       // FIXME: Maybe it would be better to create a InlineStep stop reason, but
 480       // then
 481       // the whole rest of the world would have to handle that stop reason.
 482       m_virtual_step = eLazyBoolYes;
 483     }
 484     return !step_without_resume;
 485   }
 486   return true;
 487 }
 488
 489 bool ThreadPlanStepInRange::IsVirtualStep() {
 490   if (m_virtual_step == eLazyBoolCalculate) {
 491     Thread &thread = GetThread();
 492     uint32_t cur_inline_depth = thread.GetCurrentInlinedDepth();
 493     if (cur_inline_depth == UINT32_MAX || cur_inline_depth == 0)
 494       m_virtual_step = eLazyBoolNo;
 495     else
 496       m_virtual_step = eLazyBoolYes;
 497   }
 498   return m_virtual_step == eLazyBoolYes;
 499 }