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