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 #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 uint32_t ThreadPlanStepOverRange::s_default_flag_values = 0;
  35
  36 //----------------------------------------------------------------------
  37 // ThreadPlanStepOverRange: Step through a stack range, either stepping over or into
  38 // based on the value of \a type.
  39 //----------------------------------------------------------------------
  40
  41 ThreadPlanStepOverRange::ThreadPlanStepOverRange
  42 (
  43     Thread &thread,
  44     const AddressRange &range,
  45     const SymbolContext &addr_context,
  46     lldb::RunMode stop_others,
  47     LazyBool step_out_avoids_code_without_debug_info
  48 ) :
  49     ThreadPlanStepRange (ThreadPlan::eKindStepOverRange, "Step range stepping over", thread, range, addr_context, stop_others),
  50     ThreadPlanShouldStopHere (this),
  51     m_first_resume(true)
  52 {
  53     SetFlagsToDefault();
  54     SetupAvoidNoDebug(step_out_avoids_code_without_debug_info);
  55 }
  56
  57 ThreadPlanStepOverRange::~ThreadPlanStepOverRange ()
  58 {
  59 }
  60
  61 void
  62 ThreadPlanStepOverRange::GetDescription (Stream *s, lldb::DescriptionLevel level)
  63 {
  64     if (level == lldb::eDescriptionLevelBrief)
  65     {
  66         s->Printf("step over");
  67         return;
  68     }
  69     s->Printf ("Stepping over");
  70     bool printed_line_info = false;
  71     if (m_addr_context.line_entry.IsValid())
  72     {
  73         s->Printf (" line ");
  74         m_addr_context.line_entry.DumpStopContext (s, false);
  75         printed_line_info = true;
  76     }
  77
  78     if (!printed_line_info || level == eDescriptionLevelVerbose)
  79     {
  80         s->Printf (" using ranges: ");
  81         DumpRanges(s);
  82     }
  83
  84     s->PutChar('.');
  85 }
  86
  87 void
  88 ThreadPlanStepOverRange::SetupAvoidNoDebug(LazyBool step_out_avoids_code_without_debug_info)
  89 {
  90     bool avoid_nodebug = true;
  91     switch (step_out_avoids_code_without_debug_info)
  92     {
  93         case eLazyBoolYes:
  94             avoid_nodebug = true;
  95             break;
  96         case eLazyBoolNo:
  97             avoid_nodebug = false;
  98             break;
  99         case eLazyBoolCalculate:
 100             avoid_nodebug = m_thread.GetStepOutAvoidsNoDebug();
 101             break;
 102     }
 103     if (avoid_nodebug)
 104         GetFlags().Set (ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
 105     else
 106         GetFlags().Clear (ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
 107     // Step Over plans should always avoid no-debug on step in.  Seems like you shouldn't
 108     // have to say this, but a tail call looks more like a step in that a step out, so
 109     // we want to catch this case.
 110     GetFlags().Set (ThreadPlanShouldStopHere::eStepInAvoidNoDebug);
 111 }
 112
 113 bool
 114 ThreadPlanStepOverRange::IsEquivalentContext(const SymbolContext &context)
 115 {
 116
 117     // Match as much as is specified in the m_addr_context:
 118     // This is a fairly loose sanity check.  Note, sometimes the target doesn't get filled
 119     // in so I left out the target check.  And sometimes the module comes in as the .o file from the
 120     // inlined range, so I left that out too...
 121     if (m_addr_context.comp_unit)
 122     {
 123         if (m_addr_context.comp_unit == context.comp_unit)
 124         {
 125             if (m_addr_context.function && m_addr_context.function == context.function)
 126             {
 127                 if (m_addr_context.block && m_addr_context.block == context.block)
 128                     return true;
 129             }
 130         }
 131     }
 132     else if (m_addr_context.symbol && m_addr_context.symbol == context.symbol)
 133     {
 134         return true;
 135     }
 136     return false;
 137 }
 138
 139 bool
 140 ThreadPlanStepOverRange::ShouldStop (Event *event_ptr)
 141 {
 142     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
 143
 144     if (log)
 145     {
 146         StreamString s;
 147         s.Address (m_thread.GetRegisterContext()->GetPC(),
 148                    m_thread.CalculateTarget()->GetArchitecture().GetAddressByteSize());
 149         log->Printf("ThreadPlanStepOverRange reached %s.", s.GetData());
 150     }
 151
 152     // If we're out of the range but in the same frame or in our caller's frame
 153     // then we should stop.
 154     // When stepping out we only stop others if we are forcing running one thread.
 155     bool stop_others;
 156     if (m_stop_others == lldb::eOnlyThisThread)
 157         stop_others = true;
 158     else
 159         stop_others = false;
 160
 161     ThreadPlanSP new_plan_sp;
 162
 163     FrameComparison frame_order = CompareCurrentFrameToStartFrame();
 164
 165     if (frame_order == eFrameCompareOlder)
 166     {
 167         // If we're in an older frame then we should stop.
 168         //
 169         // A caveat to this is if we think the frame is older but we're actually in a trampoline.
 170         // I'm going to make the assumption that you wouldn't RETURN to a trampoline.  So if we are
 171         // in a trampoline we think the frame is older because the trampoline confused the backtracer.
 172         // As below, we step through first, and then try to figure out how to get back out again.
 173
 174         new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
 175
 176         if (new_plan_sp && log)
 177             log->Printf("Thought I stepped out, but in fact arrived at a trampoline.");
 178     }
 179     else if (frame_order == eFrameCompareYounger)
 180     {
 181         // Make sure we really are in a new frame.  Do that by unwinding and seeing if the
 182         // start function really is our start function...
 183         for(uint32_t i = 1;; ++i)
 184         {
 185             StackFrameSP older_frame_sp = m_thread.GetStackFrameAtIndex(i);
 186             if (!older_frame_sp) {
 187                 // We can't unwind the next frame we should just get out of here & stop...
 188                 break;
 189             }
 190
 191             const SymbolContext &older_context = older_frame_sp->GetSymbolContext(eSymbolContextEverything);
 192             if (IsEquivalentContext(older_context))
 193             {
 194                 new_plan_sp = m_thread.QueueThreadPlanForStepOutNoShouldStop (false,
 195                                                                               NULL,
 196                                                                               true,
 197                                                                               stop_others,
 198                                                                               eVoteNo,
 199                                                                               eVoteNoOpinion,
 200                                                                               0);
 201                 break;
 202             }
 203             else
 204             {
 205                 new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
 206                 // If we found a way through, then we should stop recursing.
 207                 if (new_plan_sp)
 208                     break;
 209             }
 210         }
 211     }
 212     else
 213     {
 214         // If we're still in the range, keep going.
 215         if (InRange())
 216         {
 217             SetNextBranchBreakpoint();
 218             return false;
 219         }
 220
 221
 222         if (!InSymbol())
 223         {
 224             // This one is a little tricky.  Sometimes we may be in a stub or something similar,
 225             // in which case we need to get out of there.  But if we are in a stub then it's
 226             // likely going to be hard to get out from here.  It is probably easiest to step into the
 227             // stub, and then it will be straight-forward to step out.
 228             new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
 229         }
 230         else
 231         {
 232             // The current clang (at least through 424) doesn't always get the address range for the
 233             // DW_TAG_inlined_subroutines right, so that when you leave the inlined range the line table says
 234             // you are still in the source file of the inlining function.  This is bad, because now you are missing
 235             // the stack frame for the function containing the inlining, and if you sensibly do "finish" to get
 236             // out of this function you will instead exit the containing function.
 237             // To work around this, we check whether we are still in the source file we started in, and if not assume
 238             // it is an error, and push a plan to get us out of this line and back to the containing file.
 239
 240             if (m_addr_context.line_entry.IsValid())
 241             {
 242                 SymbolContext sc;
 243                 StackFrameSP frame_sp = m_thread.GetStackFrameAtIndex(0);
 244                 sc = frame_sp->GetSymbolContext (eSymbolContextEverything);
 245                 if (sc.line_entry.IsValid())
 246                 {
 247                     if (sc.line_entry.file != m_addr_context.line_entry.file
 248                          && sc.comp_unit == m_addr_context.comp_unit
 249                          && sc.function == m_addr_context.function)
 250                     {
 251                         // Okay, find the next occurance of this file in the line table:
 252                         LineTable *line_table = m_addr_context.comp_unit->GetLineTable();
 253                         if (line_table)
 254                         {
 255                             Address cur_address = frame_sp->GetFrameCodeAddress();
 256                             uint32_t entry_idx;
 257                             LineEntry line_entry;
 258                             if (line_table->FindLineEntryByAddress (cur_address, line_entry, &entry_idx))
 259                             {
 260                                 LineEntry next_line_entry;
 261                                 bool step_past_remaining_inline = false;
 262                                 if (entry_idx > 0)
 263                                 {
 264                                     // We require the the previous line entry and the current line entry come
 265                                     // from the same file.
 266                                     // The other requirement is that the previous line table entry be part of an
 267                                     // inlined block, we don't want to step past cases where people have inlined
 268                                     // some code fragment by using #include <source-fragment.c> directly.
 269                                     LineEntry prev_line_entry;
 270                                     if (line_table->GetLineEntryAtIndex(entry_idx - 1, prev_line_entry)
 271                                         && prev_line_entry.file == line_entry.file)
 272                                     {
 273                                         SymbolContext prev_sc;
 274                                         Address prev_address = prev_line_entry.range.GetBaseAddress();
 275                                         prev_address.CalculateSymbolContext(&prev_sc);
 276                                         if (prev_sc.block)
 277                                         {
 278                                             Block *inlined_block = prev_sc.block->GetContainingInlinedBlock();
 279                                             if (inlined_block)
 280                                             {
 281                                                 AddressRange inline_range;
 282                                                 inlined_block->GetRangeContainingAddress(prev_address, inline_range);
 283                                                 if (!inline_range.ContainsFileAddress(cur_address))
 284                                                 {
 285
 286                                                     step_past_remaining_inline = true;
 287                                                 }
 288
 289                                             }
 290                                         }
 291                                     }
 292                                 }
 293
 294                                 if (step_past_remaining_inline)
 295                                 {
 296                                     uint32_t look_ahead_step = 1;
 297                                     while (line_table->GetLineEntryAtIndex(entry_idx + look_ahead_step, next_line_entry))
 298                                     {
 299                                         // Make sure we haven't wandered out of the function we started from...
 300                                         Address next_line_address = next_line_entry.range.GetBaseAddress();
 301                                         Function *next_line_function = next_line_address.CalculateSymbolContextFunction();
 302                                         if (next_line_function != m_addr_context.function)
 303                                             break;
 304
 305                                         if (next_line_entry.file == m_addr_context.line_entry.file)
 306                                         {
 307                                             const bool abort_other_plans = false;
 308                                             const bool stop_other_threads = false;
 309                                             new_plan_sp = m_thread.QueueThreadPlanForRunToAddress(abort_other_plans,
 310                                                                                                next_line_address,
 311                                                                                                stop_other_threads);
 312                                             break;
 313                                         }
 314                                         look_ahead_step++;
 315                                     }
 316                                 }
 317                             }
 318                         }
 319                     }
 320                 }
 321             }
 322         }
 323     }
 324
 325     // If we get to this point, we're not going to use a previously set "next branch" breakpoint, so delete it:
 326     ClearNextBranchBreakpoint();
 327
 328
 329     // If we haven't figured out something to do yet, then ask the ShouldStopHere callback:
 330     if (!new_plan_sp)
 331     {
 332         new_plan_sp = CheckShouldStopHereAndQueueStepOut (frame_order);
 333     }
 334
 335     if (!new_plan_sp)
 336         m_no_more_plans = true;
 337     else
 338     {
 339         // Any new plan will be an implementation plan, so mark it private:
 340         new_plan_sp->SetPrivate(true);
 341         m_no_more_plans = false;
 342     }
 343
 344     if (!new_plan_sp)
 345     {
 346         // For efficiencies sake, we know we're done here so we don't have to do this
 347         // calculation again in MischiefManaged.
 348         SetPlanComplete();
 349         return true;
 350     }
 351     else
 352         return false;
 353 }
 354
 355 bool
 356 ThreadPlanStepOverRange::DoPlanExplainsStop (Event *event_ptr)
 357 {
 358     // For crashes, breakpoint hits, signals, etc, let the base plan (or some plan above us)
 359     // handle the stop.  That way the user can see the stop, step around, and then when they
 360     // are done, continue and have their step complete.  The exception is if we've hit our
 361     // "run to next branch" breakpoint.
 362     // Note, unlike the step in range plan, we don't mark ourselves complete if we hit an
 363     // unexplained breakpoint/crash.
 364
 365     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
 366     StopInfoSP stop_info_sp = GetPrivateStopInfo ();
 367     bool return_value;
 368
 369     if (stop_info_sp)
 370     {
 371         StopReason reason = stop_info_sp->GetStopReason();
 372
 373         switch (reason)
 374         {
 375         case eStopReasonTrace:
 376             return_value = true;
 377             break;
 378         case eStopReasonBreakpoint:
 379             if (NextRangeBreakpointExplainsStop(stop_info_sp))
 380                 return_value = true;
 381             else
 382                 return_value = false;
 383             break;
 384         case eStopReasonWatchpoint:
 385         case eStopReasonSignal:
 386         case eStopReasonException:
 387         case eStopReasonExec:
 388         case eStopReasonThreadExiting:
 389         default:
 390             if (log)
 391                 log->PutCString ("ThreadPlanStepInRange got asked if it explains the stop for some reason other than step.");
 392             return_value = false;
 393             break;
 394         }
 395     }
 396     else
 397         return_value = true;
 398
 399     return return_value;
 400 }
 401
 402 bool
 403 ThreadPlanStepOverRange::DoWillResume (lldb::StateType resume_state, bool current_plan)
 404 {
 405     if (resume_state != eStateSuspended && m_first_resume)
 406     {
 407         m_first_resume = false;
 408         if (resume_state == eStateStepping && current_plan)
 409         {
 410             // See if we are about to step over an inlined call in the middle of the inlined stack, if so figure
 411             // out its extents and reset our range to step over that.
 412             bool in_inlined_stack = m_thread.DecrementCurrentInlinedDepth();
 413             if (in_inlined_stack)
 414             {
 415                 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
 416                 if (log)
 417                     log->Printf ("ThreadPlanStepInRange::DoWillResume: adjusting range to the frame at inlined depth %d.",
 418                                  m_thread.GetCurrentInlinedDepth());
 419                 StackFrameSP stack_sp = m_thread.GetStackFrameAtIndex(0);
 420                 if (stack_sp)
 421                 {
 422                     Block *frame_block = stack_sp->GetFrameBlock();
 423                     lldb::addr_t curr_pc = m_thread.GetRegisterContext()->GetPC();
 424                     AddressRange my_range;
 425                     if (frame_block->GetRangeContainingLoadAddress(curr_pc, m_thread.GetProcess()->GetTarget(), my_range))
 426                     {
 427                         m_address_ranges.clear();
 428                         m_address_ranges.push_back(my_range);
 429                         if (log)
 430                         {
 431                             StreamString s;
 432                             const InlineFunctionInfo *inline_info = frame_block->GetInlinedFunctionInfo();
 433                             const char *name;
 434                             if (inline_info)
 435                                 name = inline_info->GetName().AsCString();
 436                             else
 437                                 name = "<unknown-notinlined>";
 438
 439                             s.Printf ("Stepping over inlined function \"%s\" in inlined stack: ", name);
 440                             DumpRanges(&s);
 441                             log->PutCString(s.GetData());
 442                         }
 443                     }
 444
 445                 }
 446             }
 447         }
 448     }
 449
 450     return true;
 451 }
 452