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 #include "lldb/Core/Log.h"
  17 #include "lldb/Core/Stream.h"
  18 #include "lldb/Symbol/Block.h"
  19 #include "lldb/Symbol/CompileUnit.h"
  20 #include "lldb/Symbol/Function.h"
  21 #include "lldb/Symbol/LineTable.h"
  22 #include "lldb/Target/Process.h"
  23 #include "lldb/Target/RegisterContext.h"
  24 #include "lldb/Target/Target.h"
  25 #include "lldb/Target/Thread.h"
  26 #include "lldb/Target/ThreadPlanStepOut.h"
  27 #include "lldb/Target/ThreadPlanStepThrough.h"
  28
  29 using namespace lldb_private;
  30 using namespace lldb;
  31
  32 uint32_t ThreadPlanStepOverRange::s_default_flag_values = 0;
  33
  34 //----------------------------------------------------------------------
  35 // ThreadPlanStepOverRange: Step through a stack range, either stepping over or into
  36 // based on the value of \a type.
  37 //----------------------------------------------------------------------
  38
  39 ThreadPlanStepOverRange::ThreadPlanStepOverRange
  40 (
  41     Thread &thread,
  42     const AddressRange &range,
  43     const SymbolContext &addr_context,
  44     lldb::RunMode stop_others,
  45     LazyBool step_out_avoids_code_without_debug_info
  46 ) :
  47     ThreadPlanStepRange (ThreadPlan::eKindStepOverRange, "Step range stepping over", thread, range, addr_context, stop_others),
  48     ThreadPlanShouldStopHere (this),
  49     m_first_resume(true)
  50 {
  51     SetFlagsToDefault();
  52     SetupAvoidNoDebug(step_out_avoids_code_without_debug_info);
  53 }
  54
  55 ThreadPlanStepOverRange::~ThreadPlanStepOverRange ()
  56 {
  57 }
  58
  59 void
  60 ThreadPlanStepOverRange::GetDescription (Stream *s, lldb::DescriptionLevel level)
  61 {
  62     if (level == lldb::eDescriptionLevelBrief)
  63     {
  64         s->Printf("step over");
  65         return;
  66     }
  67     s->Printf ("Stepping over");
  68     bool printed_line_info = false;
  69     if (m_addr_context.line_entry.IsValid())
  70     {
  71         s->Printf (" line ");
  72         m_addr_context.line_entry.DumpStopContext (s, false);
  73         printed_line_info = true;
  74     }
  75
  76     if (!printed_line_info || level == eDescriptionLevelVerbose)
  77     {
  78         s->Printf (" using ranges: ");
  79         DumpRanges(s);
  80     }
  81
  82     s->PutChar('.');
  83 }
  84
  85 void
  86 ThreadPlanStepOverRange::SetupAvoidNoDebug(LazyBool step_out_avoids_code_without_debug_info)
  87 {
  88     bool avoid_nodebug = true;
  89     switch (step_out_avoids_code_without_debug_info)
  90     {
  91         case eLazyBoolYes:
  92             avoid_nodebug = true;
  93             break;
  94         case eLazyBoolNo:
  95             avoid_nodebug = false;
  96             break;
  97         case eLazyBoolCalculate:
  98             avoid_nodebug = m_thread.GetStepOutAvoidsNoDebug();
  99             break;
 100     }
 101     if (avoid_nodebug)
 102         GetFlags().Set (ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
 103     else
 104         GetFlags().Clear (ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
 105     // Step Over plans should always avoid no-debug on step in.  Seems like you shouldn't
 106     // have to say this, but a tail call looks more like a step in that a step out, so
 107     // we want to catch this case.
 108     GetFlags().Set (ThreadPlanShouldStopHere::eStepInAvoidNoDebug);
 109 }
 110
 111 bool
 112 ThreadPlanStepOverRange::IsEquivalentContext(const SymbolContext &context)
 113 {
 114
 115     // Match as much as is specified in the m_addr_context:
 116     // This is a fairly loose sanity check.  Note, sometimes the target doesn't get filled
 117     // in so I left out the target check.  And sometimes the module comes in as the .o file from the
 118     // inlined range, so I left that out too...
 119     if (m_addr_context.comp_unit)
 120     {
 121         if (m_addr_context.comp_unit == context.comp_unit)
 122         {
 123             if (m_addr_context.function && m_addr_context.function == context.function)
 124             {
 125                 if (m_addr_context.block && m_addr_context.block == context.block)
 126                     return true;
 127             }
 128         }
 129     }
 130     else if (m_addr_context.symbol && m_addr_context.symbol == context.symbol)
 131     {
 132         return true;
 133     }
 134     return false;
 135 }
 136
 137 bool
 138 ThreadPlanStepOverRange::ShouldStop (Event *event_ptr)
 139 {
 140     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
 141
 142     if (log)
 143     {
 144         StreamString s;
 145         s.Address (m_thread.GetRegisterContext()->GetPC(),
 146                    m_thread.CalculateTarget()->GetArchitecture().GetAddressByteSize());
 147         log->Printf("ThreadPlanStepOverRange reached %s.", s.GetData());
 148     }
 149
 150     // If we're out of the range but in the same frame or in our caller's frame
 151     // then we should stop.
 152     // When stepping out we only stop others if we are forcing running one thread.
 153     bool stop_others;
 154     if (m_stop_others == lldb::eOnlyThisThread)
 155         stop_others = true;
 156     else
 157         stop_others = false;
 158
 159     ThreadPlanSP new_plan_sp;
 160
 161     FrameComparison frame_order = CompareCurrentFrameToStartFrame();
 162
 163     if (frame_order == eFrameCompareOlder)
 164     {
 165         // If we're in an older frame then we should stop.
 166         //
 167         // A caveat to this is if we think the frame is older but we're actually in a trampoline.
 168         // I'm going to make the assumption that you wouldn't RETURN to a trampoline.  So if we are
 169         // in a trampoline we think the frame is older because the trampoline confused the backtracer.
 170         // As below, we step through first, and then try to figure out how to get back out again.
 171
 172         new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
 173
 174         if (new_plan_sp && log)
 175             log->Printf("Thought I stepped out, but in fact arrived at a trampoline.");
 176     }
 177     else if (frame_order == eFrameCompareYounger)
 178     {
 179         // Make sure we really are in a new frame.  Do that by unwinding and seeing if the
 180         // start function really is our start function...
 181         for(uint32_t i = 1;; ++i)
 182         {
 183             StackFrameSP older_frame_sp = m_thread.GetStackFrameAtIndex(i);
 184             if (!older_frame_sp) {
 185                 // We can't unwind the next frame we should just get out of here & stop...
 186                 break;
 187             }
 188
 189             const SymbolContext &older_context = older_frame_sp->GetSymbolContext(eSymbolContextEverything);
 190             if (IsEquivalentContext(older_context))
 191             {
 192                 new_plan_sp = m_thread.QueueThreadPlanForStepOutNoShouldStop (false,
 193                                                                               NULL,
 194                                                                               true,
 195                                                                               stop_others,
 196                                                                               eVoteNo,
 197                                                                               eVoteNoOpinion,
 198                                                                               0);
 199                 break;
 200             }
 201             else
 202             {
 203                 new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
 204                 // If we found a way through, then we should stop recursing.
 205                 if (new_plan_sp)
 206                     break;
 207             }
 208         }
 209     }
 210     else
 211     {
 212         // If we're still in the range, keep going.
 213         if (InRange())
 214         {
 215             SetNextBranchBreakpoint();
 216             return false;
 217         }
 218
 219
 220         if (!InSymbol())
 221         {
 222             // This one is a little tricky.  Sometimes we may be in a stub or something similar,
 223             // in which case we need to get out of there.  But if we are in a stub then it's
 224             // likely going to be hard to get out from here.  It is probably easiest to step into the
 225             // stub, and then it will be straight-forward to step out.
 226             new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
 227         }
 228         else
 229         {
 230             // The current clang (at least through 424) doesn't always get the address range for the
 231             // DW_TAG_inlined_subroutines right, so that when you leave the inlined range the line table says
 232             // you are still in the source file of the inlining function.  This is bad, because now you are missing
 233             // the stack frame for the function containing the inlining, and if you sensibly do "finish" to get
 234             // out of this function you will instead exit the containing function.
 235             // To work around this, we check whether we are still in the source file we started in, and if not assume
 236             // it is an error, and push a plan to get us out of this line and back to the containing file.
 237
 238             if (m_addr_context.line_entry.IsValid())
 239             {
 240                 SymbolContext sc;
 241                 StackFrameSP frame_sp = m_thread.GetStackFrameAtIndex(0);
 242                 sc = frame_sp->GetSymbolContext (eSymbolContextEverything);
 243                 if (sc.line_entry.IsValid())
 244                 {
 245                     if (sc.line_entry.file != m_addr_context.line_entry.file
 246                          && sc.comp_unit == m_addr_context.comp_unit
 247                          && sc.function == m_addr_context.function)
 248                     {
 249                         // Okay, find the next occurrence of this file in the line table:
 250                         LineTable *line_table = m_addr_context.comp_unit->GetLineTable();
 251                         if (line_table)
 252                         {
 253                             Address cur_address = frame_sp->GetFrameCodeAddress();
 254                             uint32_t entry_idx;
 255                             LineEntry line_entry;
 256                             if (line_table->FindLineEntryByAddress (cur_address, line_entry, &entry_idx))
 257                             {
 258                                 LineEntry next_line_entry;
 259                                 bool step_past_remaining_inline = false;
 260                                 if (entry_idx > 0)
 261                                 {
 262                                     // We require the previous line entry and the current line entry come
 263                                     // from the same file.
 264                                     // The other requirement is that the previous line table entry be part of an
 265                                     // inlined block, we don't want to step past cases where people have inlined
 266                                     // some code fragment by using #include <source-fragment.c> directly.
 267                                     LineEntry prev_line_entry;
 268                                     if (line_table->GetLineEntryAtIndex(entry_idx - 1, prev_line_entry)
 269                                         && prev_line_entry.file == line_entry.file)
 270                                     {
 271                                         SymbolContext prev_sc;
 272                                         Address prev_address = prev_line_entry.range.GetBaseAddress();
 273                                         prev_address.CalculateSymbolContext(&prev_sc);
 274                                         if (prev_sc.block)
 275                                         {
 276                                             Block *inlined_block = prev_sc.block->GetContainingInlinedBlock();
 277                                             if (inlined_block)
 278                                             {
 279                                                 AddressRange inline_range;
 280                                                 inlined_block->GetRangeContainingAddress(prev_address, inline_range);
 281                                                 if (!inline_range.ContainsFileAddress(cur_address))
 282                                                 {
 283
 284                                                     step_past_remaining_inline = true;
 285                                                 }
 286
 287                                             }
 288                                         }
 289                                     }
 290                                 }
 291
 292                                 if (step_past_remaining_inline)
 293                                 {
 294                                     uint32_t look_ahead_step = 1;
 295                                     while (line_table->GetLineEntryAtIndex(entry_idx + look_ahead_step, next_line_entry))
 296                                     {
 297                                         // Make sure we haven't wandered out of the function we started from...
 298                                         Address next_line_address = next_line_entry.range.GetBaseAddress();
 299                                         Function *next_line_function = next_line_address.CalculateSymbolContextFunction();
 300                                         if (next_line_function != m_addr_context.function)
 301                                             break;
 302
 303                                         if (next_line_entry.file == m_addr_context.line_entry.file)
 304                                         {
 305                                             const bool abort_other_plans = false;
 306                                             const bool stop_other_threads = false;
 307                                             new_plan_sp = m_thread.QueueThreadPlanForRunToAddress(abort_other_plans,
 308                                                                                                next_line_address,
 309                                                                                                stop_other_threads);
 310                                             break;
 311                                         }
 312                                         look_ahead_step++;
 313                                     }
 314                                 }
 315                             }
 316                         }
 317                     }
 318                 }
 319             }
 320         }
 321     }
 322
 323     // If we get to this point, we're not going to use a previously set "next branch" breakpoint, so delete it:
 324     ClearNextBranchBreakpoint();
 325
 326
 327     // If we haven't figured out something to do yet, then ask the ShouldStopHere callback:
 328     if (!new_plan_sp)
 329     {
 330         new_plan_sp = CheckShouldStopHereAndQueueStepOut (frame_order);
 331     }
 332
 333     if (!new_plan_sp)
 334         m_no_more_plans = true;
 335     else
 336     {
 337         // Any new plan will be an implementation plan, so mark it private:
 338         new_plan_sp->SetPrivate(true);
 339         m_no_more_plans = false;
 340     }
 341
 342     if (!new_plan_sp)
 343     {
 344         // For efficiencies sake, we know we're done here so we don't have to do this
 345         // calculation again in MischiefManaged.
 346         SetPlanComplete();
 347         return true;
 348     }
 349     else
 350         return false;
 351 }
 352
 353 bool
 354 ThreadPlanStepOverRange::DoPlanExplainsStop (Event *event_ptr)
 355 {
 356     // For crashes, breakpoint hits, signals, etc, let the base plan (or some plan above us)
 357     // handle the stop.  That way the user can see the stop, step around, and then when they
 358     // are done, continue and have their step complete.  The exception is if we've hit our
 359     // "run to next branch" breakpoint.
 360     // Note, unlike the step in range plan, we don't mark ourselves complete if we hit an
 361     // unexplained breakpoint/crash.
 362
 363     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
 364     StopInfoSP stop_info_sp = GetPrivateStopInfo ();
 365     bool return_value;
 366
 367     if (stop_info_sp)
 368     {
 369         StopReason reason = stop_info_sp->GetStopReason();
 370
 371         switch (reason)
 372         {
 373         case eStopReasonTrace:
 374             return_value = true;
 375             break;
 376         case eStopReasonBreakpoint:
 377             if (NextRangeBreakpointExplainsStop(stop_info_sp))
 378                 return_value = true;
 379             else
 380                 return_value = false;
 381             break;
 382         case eStopReasonWatchpoint:
 383         case eStopReasonSignal:
 384         case eStopReasonException:
 385         case eStopReasonExec:
 386         case eStopReasonThreadExiting:
 387         default:
 388             if (log)
 389                 log->PutCString ("ThreadPlanStepInRange got asked if it explains the stop for some reason other than step.");
 390             return_value = false;
 391             break;
 392         }
 393     }
 394     else
 395         return_value = true;
 396
 397     return return_value;
 398 }
 399
 400 bool
 401 ThreadPlanStepOverRange::DoWillResume (lldb::StateType resume_state, bool current_plan)
 402 {
 403     if (resume_state != eStateSuspended && m_first_resume)
 404     {
 405         m_first_resume = false;
 406         if (resume_state == eStateStepping && current_plan)
 407         {
 408             // See if we are about to step over an inlined call in the middle of the inlined stack, if so figure
 409             // out its extents and reset our range to step over that.
 410             bool in_inlined_stack = m_thread.DecrementCurrentInlinedDepth();
 411             if (in_inlined_stack)
 412             {
 413                 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
 414                 if (log)
 415                     log->Printf ("ThreadPlanStepInRange::DoWillResume: adjusting range to the frame at inlined depth %d.",
 416                                  m_thread.GetCurrentInlinedDepth());
 417                 StackFrameSP stack_sp = m_thread.GetStackFrameAtIndex(0);
 418                 if (stack_sp)
 419                 {
 420                     Block *frame_block = stack_sp->GetFrameBlock();
 421                     lldb::addr_t curr_pc = m_thread.GetRegisterContext()->GetPC();
 422                     AddressRange my_range;
 423                     if (frame_block->GetRangeContainingLoadAddress(curr_pc, m_thread.GetProcess()->GetTarget(), my_range))
 424                     {
 425                         m_address_ranges.clear();
 426                         m_address_ranges.push_back(my_range);
 427                         if (log)
 428                         {
 429                             StreamString s;
 430                             const InlineFunctionInfo *inline_info = frame_block->GetInlinedFunctionInfo();
 431                             const char *name;
 432                             if (inline_info)
 433                                 name = inline_info->GetName(frame_block->CalculateSymbolContextFunction()->GetLanguage()).AsCString();
 434                             else
 435                                 name = "<unknown-notinlined>";
 436
 437                             s.Printf ("Stepping over inlined function \"%s\" in inlined stack: ", name);
 438                             DumpRanges(&s);
 439                             log->PutCString(s.GetData());
 440                         }
 441                     }
 442
 443                 }
 444             }
 445         }
 446     }
 447
 448     return true;
 449 }
 450