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