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         s->Printf("step over");
  66     else
  67     {
  68         s->Printf ("stepping through range (stepping over functions): ");
  69         DumpRanges(s);
  70     }
  71 }
  72
  73 void
  74 ThreadPlanStepOverRange::SetupAvoidNoDebug(LazyBool step_out_avoids_code_without_debug_info)
  75 {
  76     bool avoid_nodebug = true;
  77     switch (step_out_avoids_code_without_debug_info)
  78     {
  79         case eLazyBoolYes:
  80             avoid_nodebug = true;
  81             break;
  82         case eLazyBoolNo:
  83             avoid_nodebug = false;
  84             break;
  85         case eLazyBoolCalculate:
  86             avoid_nodebug = m_thread.GetStepOutAvoidsNoDebug();
  87             break;
  88     }
  89     if (avoid_nodebug)
  90         GetFlags().Set (ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
  91     else
  92         GetFlags().Clear (ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
  93     // Step Over plans should always avoid no-debug on step in.  Seems like you shouldn't
  94     // have to say this, but a tail call looks more like a step in that a step out, so
  95     // we want to catch this case.
  96     GetFlags().Set (ThreadPlanShouldStopHere::eStepInAvoidNoDebug);
  97 }
  98
  99 bool
 100 ThreadPlanStepOverRange::IsEquivalentContext(const SymbolContext &context)
 101 {
 102
 103     // Match as much as is specified in the m_addr_context:
 104     // This is a fairly loose sanity check.  Note, sometimes the target doesn't get filled
 105     // in so I left out the target check.  And sometimes the module comes in as the .o file from the
 106     // inlined range, so I left that out too...
 107     if (m_addr_context.comp_unit)
 108     {
 109         if (m_addr_context.comp_unit == context.comp_unit)
 110         {
 111             if (m_addr_context.function && m_addr_context.function == context.function)
 112             {
 113                 if (m_addr_context.block && m_addr_context.block == context.block)
 114                     return true;
 115             }
 116         }
 117     }
 118     else if (m_addr_context.symbol && m_addr_context.symbol == context.symbol)
 119     {
 120         return true;
 121     }
 122     return false;
 123 }
 124
 125 bool
 126 ThreadPlanStepOverRange::ShouldStop (Event *event_ptr)
 127 {
 128     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
 129
 130     if (log)
 131     {
 132         StreamString s;
 133         s.Address (m_thread.GetRegisterContext()->GetPC(),
 134                    m_thread.CalculateTarget()->GetArchitecture().GetAddressByteSize());
 135         log->Printf("ThreadPlanStepOverRange reached %s.", s.GetData());
 136     }
 137
 138     // If we're out of the range but in the same frame or in our caller's frame
 139     // then we should stop.
 140     // When stepping out we only stop others if we are forcing running one thread.
 141     bool stop_others;
 142     if (m_stop_others == lldb::eOnlyThisThread)
 143         stop_others = true;
 144     else
 145         stop_others = false;
 146
 147     ThreadPlanSP new_plan_sp;
 148
 149     FrameComparison frame_order = CompareCurrentFrameToStartFrame();
 150
 151     if (frame_order == eFrameCompareOlder)
 152     {
 153         // If we're in an older frame then we should stop.
 154         //
 155         // A caveat to this is if we think the frame is older but we're actually in a trampoline.
 156         // I'm going to make the assumption that you wouldn't RETURN to a trampoline.  So if we are
 157         // in a trampoline we think the frame is older because the trampoline confused the backtracer.
 158         // As below, we step through first, and then try to figure out how to get back out again.
 159
 160         new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
 161
 162         if (new_plan_sp && log)
 163             log->Printf("Thought I stepped out, but in fact arrived at a trampoline.");
 164     }
 165     else if (frame_order == eFrameCompareYounger)
 166     {
 167         // Make sure we really are in a new frame.  Do that by unwinding and seeing if the
 168         // start function really is our start function...
 169         for(uint32_t i = 1;; ++i)
 170         {
 171             StackFrameSP older_frame_sp = m_thread.GetStackFrameAtIndex(i);
 172             if (!older_frame_sp) {
 173                 // We can't unwind the next frame we should just get out of here & stop...
 174                 break;
 175             }
 176
 177             const SymbolContext &older_context = older_frame_sp->GetSymbolContext(eSymbolContextEverything);
 178             if (IsEquivalentContext(older_context))
 179             {
 180                 new_plan_sp = m_thread.QueueThreadPlanForStepOutNoShouldStop (false,
 181                                                                               NULL,
 182                                                                               true,
 183                                                                               stop_others,
 184                                                                               eVoteNo,
 185                                                                               eVoteNoOpinion,
 186                                                                               0);
 187                 break;
 188             }
 189             else
 190             {
 191                 new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
 192                 // If we found a way through, then we should stop recursing.
 193                 if (new_plan_sp)
 194                     break;
 195             }
 196         }
 197     }
 198     else
 199     {
 200         // If we're still in the range, keep going.
 201         if (InRange())
 202         {
 203             SetNextBranchBreakpoint();
 204             return false;
 205         }
 206
 207
 208         if (!InSymbol())
 209         {
 210             // This one is a little tricky.  Sometimes we may be in a stub or something similar,
 211             // in which case we need to get out of there.  But if we are in a stub then it's
 212             // likely going to be hard to get out from here.  It is probably easiest to step into the
 213             // stub, and then it will be straight-forward to step out.
 214             new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others);
 215         }
 216         else
 217         {
 218             // The current clang (at least through 424) doesn't always get the address range for the
 219             // DW_TAG_inlined_subroutines right, so that when you leave the inlined range the line table says
 220             // you are still in the source file of the inlining function.  This is bad, because now you are missing
 221             // the stack frame for the function containing the inlining, and if you sensibly do "finish" to get
 222             // out of this function you will instead exit the containing function.
 223             // To work around this, we check whether we are still in the source file we started in, and if not assume
 224             // it is an error, and push a plan to get us out of this line and back to the containing file.
 225
 226             if (m_addr_context.line_entry.IsValid())
 227             {
 228                 SymbolContext sc;
 229                 StackFrameSP frame_sp = m_thread.GetStackFrameAtIndex(0);
 230                 sc = frame_sp->GetSymbolContext (eSymbolContextEverything);
 231                 if (sc.line_entry.IsValid())
 232                 {
 233                     if (sc.line_entry.file != m_addr_context.line_entry.file
 234                          && sc.comp_unit == m_addr_context.comp_unit
 235                          && sc.function == m_addr_context.function)
 236                     {
 237                         // Okay, find the next occurance of this file in the line table:
 238                         LineTable *line_table = m_addr_context.comp_unit->GetLineTable();
 239                         if (line_table)
 240                         {
 241                             Address cur_address = frame_sp->GetFrameCodeAddress();
 242                             uint32_t entry_idx;
 243                             LineEntry line_entry;
 244                             if (line_table->FindLineEntryByAddress (cur_address, line_entry, &entry_idx))
 245                             {
 246                                 LineEntry next_line_entry;
 247                                 bool step_past_remaining_inline = false;
 248                                 if (entry_idx > 0)
 249                                 {
 250                                     // We require the the previous line entry and the current line entry come
 251                                     // from the same file.
 252                                     // The other requirement is that the previous line table entry be part of an
 253                                     // inlined block, we don't want to step past cases where people have inlined
 254                                     // some code fragment by using #include <source-fragment.c> directly.
 255                                     LineEntry prev_line_entry;
 256                                     if (line_table->GetLineEntryAtIndex(entry_idx - 1, prev_line_entry)
 257                                         && prev_line_entry.file == line_entry.file)
 258                                     {
 259                                         SymbolContext prev_sc;
 260                                         Address prev_address = prev_line_entry.range.GetBaseAddress();
 261                                         prev_address.CalculateSymbolContext(&prev_sc);
 262                                         if (prev_sc.block)
 263                                         {
 264                                             Block *inlined_block = prev_sc.block->GetContainingInlinedBlock();
 265                                             if (inlined_block)
 266                                             {
 267                                                 AddressRange inline_range;
 268                                                 inlined_block->GetRangeContainingAddress(prev_address, inline_range);
 269                                                 if (!inline_range.ContainsFileAddress(cur_address))
 270                                                 {
 271
 272                                                     step_past_remaining_inline = true;
 273                                                 }
 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 bool stop_other_threads = false;
 295                                             new_plan_sp = m_thread.QueueThreadPlanForRunToAddress(abort_other_plans,
 296                                                                                                next_line_address,
 297                                                                                                stop_other_threads);
 298                                             break;
 299                                         }
 300                                         look_ahead_step++;
 301                                     }
 302                                 }
 303                             }
 304                         }
 305                     }
 306                 }
 307             }
 308         }
 309     }
 310
 311     // If we get to this point, we're not going to use a previously set "next branch" breakpoint, so delete it:
 312     ClearNextBranchBreakpoint();
 313
 314
 315     // If we haven't figured out something to do yet, then ask the ShouldStopHere callback:
 316     if (!new_plan_sp)
 317     {
 318         new_plan_sp = CheckShouldStopHereAndQueueStepOut (frame_order);
 319     }
 320
 321     if (!new_plan_sp)
 322         m_no_more_plans = true;
 323     else
 324         m_no_more_plans = false;
 325
 326     if (!new_plan_sp)
 327     {
 328         // For efficiencies sake, we know we're done here so we don't have to do this
 329         // calculation again in MischiefManaged.
 330         SetPlanComplete();
 331         return true;
 332     }
 333     else
 334         return false;
 335 }
 336
 337 bool
 338 ThreadPlanStepOverRange::DoPlanExplainsStop (Event *event_ptr)
 339 {
 340     // For crashes, breakpoint hits, signals, etc, let the base plan (or some plan above us)
 341     // handle the stop.  That way the user can see the stop, step around, and then when they
 342     // are done, continue and have their step complete.  The exception is if we've hit our
 343     // "run to next branch" breakpoint.
 344     // Note, unlike the step in range plan, we don't mark ourselves complete if we hit an
 345     // unexplained breakpoint/crash.
 346
 347     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
 348     StopInfoSP stop_info_sp = GetPrivateStopInfo ();
 349     bool return_value;
 350
 351     if (stop_info_sp)
 352     {
 353         StopReason reason = stop_info_sp->GetStopReason();
 354
 355         switch (reason)
 356         {
 357         case eStopReasonTrace:
 358             return_value = true;
 359             break;
 360         case eStopReasonBreakpoint:
 361             if (NextRangeBreakpointExplainsStop(stop_info_sp))
 362                 return_value = true;
 363             else
 364                 return_value = false;
 365             break;
 366         case eStopReasonWatchpoint:
 367         case eStopReasonSignal:
 368         case eStopReasonException:
 369         case eStopReasonExec:
 370         case eStopReasonThreadExiting:
 371         default:
 372             if (log)
 373                 log->PutCString ("ThreadPlanStepInRange got asked if it explains the stop for some reason other than step.");
 374             return_value = false;
 375             break;
 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().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 }
 434