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      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 }
    389