source/Target/ThreadPlanStepOverRange.cpp

   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 // C Includes
  11 // C++ Includes
  12 // Other libraries and framework includes
  13 // Project includes
  14 #include "lldb/Target/ThreadPlanStepOverRange.h"
  15 #include "lldb/Core/Log.h"
  16 #include "lldb/Core/Stream.h"
  17 #include "lldb/Symbol/Block.h"
  18 #include "lldb/Symbol/CompileUnit.h"
  19 #include "lldb/Symbol/Function.h"
  20 #include "lldb/Symbol/LineTable.h"
  21 #include "lldb/Target/Process.h"
  22 #include "lldb/Target/RegisterContext.h"
  23 #include "lldb/Target/Target.h"
  24 #include "lldb/Target/Thread.h"
  25 #include "lldb/Target/ThreadPlanStepOut.h"
  26 #include "lldb/Target/ThreadPlanStepThrough.h"
  27
  28 using namespace lldb_private;
  29 using namespace lldb;
  30
  31 uint32_t ThreadPlanStepOverRange::s_default_flag_values = 0;
  32
  33 //----------------------------------------------------------------------
  34 // ThreadPlanStepOverRange: Step through a stack range, either stepping over or into
  35 // based on the value of \a type.
  36 //----------------------------------------------------------------------
  37
  38 ThreadPlanStepOverRange::ThreadPlanStepOverRange
  39 (
  40     Thread &thread,
  41     const AddressRange &range,
  42     const SymbolContext &addr_context,
  43     lldb::RunMode stop_others,
  44     LazyBool step_out_avoids_code_without_debug_info
  45 ) :
  46     ThreadPlanStepRange (ThreadPlan::eKindStepOverRange, "Step range stepping over", thread, range, addr_context, stop_others),
  47     ThreadPlanShouldStopHere (this),
  48     m_first_resume(true)
  49 {
  50     SetFlagsToDefault();
  51     SetupAvoidNoDebug(step_out_avoids_code_without_debug_info);
  52 }
  53
  54 ThreadPlanStepOverRange::~ThreadPlanStepOverRange() = default;
  55
  56 void
  57 ThreadPlanStepOverRange::GetDescription (Stream *s, lldb::DescriptionLevel level)
  58 {
  59     if (level == lldb::eDescriptionLevelBrief)
  60     {
  61         s->Printf("step over");
  62         return;
  63     }
  64     s->Printf ("Stepping over");
  65     bool printed_line_info = false;
  66     if (m_addr_context.line_entry.IsValid())
  67     {
  68         s->Printf (" line ");
  69         m_addr_context.line_entry.DumpStopContext (s, false);
  70         printed_line_info = true;
  71     }
  72
  73     if (!printed_line_info || level == eDescriptionLevelVerbose)
  74     {
  75         s->Printf (" using ranges: ");
  76         DumpRanges(s);
  77     }
  78
  79     s->PutChar('.');
  80 }
  81
  82 void
  83 ThreadPlanStepOverRange::SetupAvoidNoDebug(LazyBool step_out_avoids_code_without_debug_info)
  84 {
  85     bool avoid_nodebug = true;
  86     switch (step_out_avoids_code_without_debug_info)
  87     {
  88         case eLazyBoolYes:
  89             avoid_nodebug = true;
  90             break;
  91         case eLazyBoolNo:
  92             avoid_nodebug = false;
  93             break;
  94         case eLazyBoolCalculate:
  95             avoid_nodebug = m_thread.GetStepOutAvoidsNoDebug();
  96             break;
  97     }
  98     if (avoid_nodebug)
  99         GetFlags().Set (ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
 100     else
 101         GetFlags().Clear (ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
 102     // Step Over plans should always avoid no-debug on step in.  Seems like you shouldn't
 103     // have to say this, but a tail call looks more like a step in that a step out, so
 104     // we want to catch this case.
 105     GetFlags().Set (ThreadPlanShouldStopHere::eStepInAvoidNoDebug);
 106 }
 107
 108 bool
 109 ThreadPlanStepOverRange::IsEquivalentContext(const SymbolContext &context)
 110 {
 111     // Match as much as is specified in the m_addr_context:
 112     // This is a fairly loose sanity check.  Note, sometimes the target doesn't get filled
 113     // in so I left out the target check.  And sometimes the module comes in as the .o file from the
 114     // inlined range, so I left that out too...
 115     if (m_addr_context.comp_unit)
 116     {
 117         if (m_addr_context.comp_unit == context.comp_unit)
 118         {
 119             if (m_addr_context.function && m_addr_context.function == context.function)
 120             {
 121                 if (m_addr_context.block && m_addr_context.block == context.block)
 122                     return true;
 123             }
 124         }
 125     }
 126     else if (m_addr_context.symbol && m_addr_context.symbol == context.symbol)
 127     {
 128         return true;
 129     }
 130     return false;
 131 }
 132
 133 bool
 134 ThreadPlanStepOverRange::ShouldStop (Event *event_ptr)
 135 {
 136     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
 137
 138     if (log)
 139     {
 140         StreamString s;
 141         s.Address (m_thread.GetRegisterContext()->GetPC(),
 142                    m_thread.CalculateTarget()->GetArchitecture().GetAddressByteSize());
 143         log->Printf("ThreadPlanStepOverRange reached %s.", s.GetData());
 144     }
 145
 146     // If we're out of the range but in the same frame or in our caller's frame
 147     // then we should stop.
 148     // When stepping out we only stop others if we are forcing running one thread.
 149     bool stop_others = (m_stop_others == lldb::eOnlyThisThread);
 150     ThreadPlanSP new_plan_sp;
 151     FrameComparison frame_order = CompareCurrentFrameToStartFrame();
 152
 153     if (frame_order == eFrameCompareOlder)
 154     {
 155         // If we're in an older frame then we should stop.
 156         //
 157         // A caveat to this is if we think the frame is older but we're actually in a trampoline.
 158         // I'm going to make the assumption that you wouldn't RETURN to a trampoline.  So if we are
 159         // in a trampoline we think the frame is older because the trampoline confused the backtracer.
 160         // As below, we step through first, and then try to figure out how to get back out again.
 161
 162         new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
 163
 164         if (new_plan_sp && log)
 165             log->Printf("Thought I stepped out, but in fact arrived at a trampoline.");
 166     }
 167     else if (frame_order == eFrameCompareYounger)
 168     {
 169         // Make sure we really are in a new frame.  Do that by unwinding and seeing if the
 170         // start function really is our start function...
 171         for(uint32_t i = 1;; ++i)
 172         {
 173             StackFrameSP older_frame_sp = m_thread.GetStackFrameAtIndex(i);
 174             if (!older_frame_sp) {
 175                 // We can't unwind the next frame we should just get out of here & stop...
 176                 break;
 177             }
 178
 179             const SymbolContext &older_context = older_frame_sp->GetSymbolContext(eSymbolContextEverything);
 180             if (IsEquivalentContext(older_context))
 181             {
 182                 new_plan_sp = m_thread.QueueThreadPlanForStepOutNoShouldStop(false,
 183                                                                              nullptr,
 184                                                                              true,
 185                                                                              stop_others,
 186                                                                              eVoteNo,
 187                                                                              eVoteNoOpinion,
 188                                                                              0);
 189                 break;
 190             }
 191             else
 192             {
 193                 new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
 194                 // If we found a way through, then we should stop recursing.
 195                 if (new_plan_sp)
 196                     break;
 197             }
 198         }
 199     }
 200     else
 201     {
 202         // If we're still in the range, keep going.
 203         if (InRange())
 204         {
 205             SetNextBranchBreakpoint();
 206             return false;
 207         }
 208
 209         if (!InSymbol())
 210         {
 211             // This one is a little tricky.  Sometimes we may be in a stub or something similar,
 212             // in which case we need to get out of there.  But if we are in a stub then it's
 213             // likely going to be hard to get out from here.  It is probably easiest to step into the
 214             // stub, and then it will be straight-forward to step out.
 215             new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
 216         }
 217         else
 218         {
 219             // The current clang (at least through 424) doesn't always get the address range for the
 220             // DW_TAG_inlined_subroutines right, so that when you leave the inlined range the line table says
 221             // you are still in the source file of the inlining function.  This is bad, because now you are missing
 222             // the stack frame for the function containing the inlining, and if you sensibly do "finish" to get
 223             // out of this function you will instead exit the containing function.
 224             // To work around this, we check whether we are still in the source file we started in, and if not assume
 225             // it is an error, and push a plan to get us out of this line and back to the containing file.
 226
 227             if (m_addr_context.line_entry.IsValid())
 228             {
 229                 SymbolContext sc;
 230                 StackFrameSP frame_sp = m_thread.GetStackFrameAtIndex(0);
 231                 sc = frame_sp->GetSymbolContext (eSymbolContextEverything);
 232                 if (sc.line_entry.IsValid())
 233                 {
 234                     if (sc.line_entry.file != m_addr_context.line_entry.file
 235                          && sc.comp_unit == m_addr_context.comp_unit
 236                          && sc.function == m_addr_context.function)
 237                     {
 238                         // Okay, find the next occurrence of this file in the line table:
 239                         LineTable *line_table = m_addr_context.comp_unit->GetLineTable();
 240                         if (line_table)
 241                         {
 242                             Address cur_address = frame_sp->GetFrameCodeAddress();
 243                             uint32_t entry_idx;
 244                             LineEntry line_entry;
 245                             if (line_table->FindLineEntryByAddress (cur_address, line_entry, &entry_idx))
 246                             {
 247                                 LineEntry next_line_entry;
 248                                 bool step_past_remaining_inline = false;
 249                                 if (entry_idx > 0)
 250                                 {
 251                                     // We require the previous line entry and the current line entry come
 252                                     // from the same file.
 253                                     // The other requirement is that the previous line table entry be part of an
 254                                     // inlined block, we don't want to step past cases where people have inlined
 255                                     // some code fragment by using #include <source-fragment.c> directly.
 256                                     LineEntry prev_line_entry;
 257                                     if (line_table->GetLineEntryAtIndex(entry_idx - 1, prev_line_entry)
 258                                         && prev_line_entry.file == line_entry.file)
 259                                     {
 260                                         SymbolContext prev_sc;
 261                                         Address prev_address = prev_line_entry.range.GetBaseAddress();
 262                                         prev_address.CalculateSymbolContext(&prev_sc);
 263                                         if (prev_sc.block)
 264                                         {
 265                                             Block *inlined_block = prev_sc.block->GetContainingInlinedBlock();
 266                                             if (inlined_block)
 267                                             {
 268                                                 AddressRange inline_range;
 269                                                 inlined_block->GetRangeContainingAddress(prev_address, inline_range);
 270                                                 if (!inline_range.ContainsFileAddress(cur_address))
 271                                                 {
 272
 273                                                     step_past_remaining_inline = true;
 274                                                 }
 275                                             }
 276                                         }
 277                                     }
 278                                 }
 279
 280                                 if (step_past_remaining_inline)
 281                                 {
 282                                     uint32_t look_ahead_step = 1;
 283                                     while (line_table->GetLineEntryAtIndex(entry_idx + look_ahead_step, next_line_entry))
 284                                     {
 285                                         // Make sure we haven't wandered out of the function we started from...
 286                                         Address next_line_address = next_line_entry.range.GetBaseAddress();
 287                                         Function *next_line_function = next_line_address.CalculateSymbolContextFunction();
 288                                         if (next_line_function != m_addr_context.function)
 289                                             break;
 290
 291                                         if (next_line_entry.file == m_addr_context.line_entry.file)
 292                                         {
 293                                             const bool abort_other_plans = false;
 294                                             const RunMode stop_other_threads = RunMode::eAllThreads;
 295                                             lldb::addr_t cur_pc = m_thread.GetStackFrameAtIndex(0)->GetRegisterContext()->GetPC();
 296                                             AddressRange step_range(cur_pc, next_line_address.GetLoadAddress(&GetTarget()) - cur_pc);
 297
 298                                             new_plan_sp = m_thread.QueueThreadPlanForStepOverRange (abort_other_plans,
 299                                                                                                     step_range,
 300                                                                                                     sc,
 301                                                                                                     stop_other_threads);
 302                                             break;
 303                                         }
 304                                         look_ahead_step++;
 305                                     }
 306                                 }
 307                             }
 308                         }
 309                     }
 310                 }
 311             }
 312         }
 313     }
 314
 315     // If we get to this point, we're not going to use a previously set "next branch" breakpoint, so delete it:
 316     ClearNextBranchBreakpoint();
 317
 318
 319     // If we haven't figured out something to do yet, then ask the ShouldStopHere callback:
 320     if (!new_plan_sp)
 321     {
 322         new_plan_sp = CheckShouldStopHereAndQueueStepOut (frame_order);
 323     }
 324
 325     if (!new_plan_sp)
 326         m_no_more_plans = true;
 327     else
 328     {
 329         // Any new plan will be an implementation plan, so mark it private:
 330         new_plan_sp->SetPrivate(true);
 331         m_no_more_plans = false;
 332     }
 333
 334     if (!new_plan_sp)
 335     {
 336         // For efficiencies sake, we know we're done here so we don't have to do this
 337         // calculation again in MischiefManaged.
 338         SetPlanComplete();
 339         return true;
 340     }
 341     else
 342         return false;
 343 }
 344
 345 bool
 346 ThreadPlanStepOverRange::DoPlanExplainsStop (Event *event_ptr)
 347 {
 348     // For crashes, breakpoint hits, signals, etc, let the base plan (or some plan above us)
 349     // handle the stop.  That way the user can see the stop, step around, and then when they
 350     // are done, continue and have their step complete.  The exception is if we've hit our
 351     // "run to next branch" breakpoint.
 352     // Note, unlike the step in range plan, we don't mark ourselves complete if we hit an
 353     // unexplained breakpoint/crash.
 354
 355     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
 356     StopInfoSP stop_info_sp = GetPrivateStopInfo ();
 357     bool return_value;
 358
 359     if (stop_info_sp)
 360     {
 361         StopReason reason = stop_info_sp->GetStopReason();
 362
 363         if (reason == eStopReasonTrace)
 364         {
 365             return_value = true;
 366         }
 367         else if (reason == eStopReasonBreakpoint)
 368         {
 369             return_value = NextRangeBreakpointExplainsStop(stop_info_sp);
 370         }
 371         else
 372         {
 373             if (log)
 374                 log->PutCString ("ThreadPlanStepInRange got asked if it explains the stop for some reason other than step.");
 375             return_value = false;
 376         }
 377     }
 378     else
 379         return_value = true;
 380
 381     return return_value;
 382 }
 383
 384 bool
 385 ThreadPlanStepOverRange::DoWillResume (lldb::StateType resume_state, bool current_plan)
 386 {
 387     if (resume_state != eStateSuspended && m_first_resume)
 388     {
 389         m_first_resume = false;
 390         if (resume_state == eStateStepping && current_plan)
 391         {
 392             // See if we are about to step over an inlined call in the middle of the inlined stack, if so figure
 393             // out its extents and reset our range to step over that.
 394             bool in_inlined_stack = m_thread.DecrementCurrentInlinedDepth();
 395             if (in_inlined_stack)
 396             {
 397                 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
 398                 if (log)
 399                     log->Printf ("ThreadPlanStepInRange::DoWillResume: adjusting range to the frame at inlined depth %d.",
 400                                  m_thread.GetCurrentInlinedDepth());
 401                 StackFrameSP stack_sp = m_thread.GetStackFrameAtIndex(0);
 402                 if (stack_sp)
 403                 {
 404                     Block *frame_block = stack_sp->GetFrameBlock();
 405                     lldb::addr_t curr_pc = m_thread.GetRegisterContext()->GetPC();
 406                     AddressRange my_range;
 407                     if (frame_block->GetRangeContainingLoadAddress(curr_pc, m_thread.GetProcess()->GetTarget(), my_range))
 408                     {
 409                         m_address_ranges.clear();
 410                         m_address_ranges.push_back(my_range);
 411                         if (log)
 412                         {
 413                             StreamString s;
 414                             const InlineFunctionInfo *inline_info = frame_block->GetInlinedFunctionInfo();
 415                             const char *name;
 416                             if (inline_info)
 417                                 name = inline_info->GetName(frame_block->CalculateSymbolContextFunction()->GetLanguage()).AsCString();
 418                             else
 419                                 name = "<unknown-notinlined>";
 420
 421                             s.Printf ("Stepping over inlined function \"%s\" in inlined stack: ", name);
 422                             DumpRanges(&s);
 423                             log->PutCString(s.GetData());
 424                         }
 425                     }
 426
 427                 }
 428             }
 429         }
 430     }
 431
 432     return true;
 433 }