contrib/llvm/tools/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleThreadPlanStepThroughObjCTrampoline.cpp

   1 //===-- AppleThreadPlanStepThroughObjCTrampoline.cpp
   2 //--------------------------*- C++ -*-===//
   3 //
   4 //                     The LLVM Compiler Infrastructure
   5 //
   6 // This file is distributed under the University of Illinois Open Source
   7 // License. See LICENSE.TXT for details.
   8 //
   9 //===----------------------------------------------------------------------===//
  10
  11 #include "AppleThreadPlanStepThroughObjCTrampoline.h"
  12 #include "AppleObjCTrampolineHandler.h"
  13 #include "lldb/Expression/DiagnosticManager.h"
  14 #include "lldb/Expression/FunctionCaller.h"
  15 #include "lldb/Expression/UtilityFunction.h"
  16 #include "lldb/Target/ExecutionContext.h"
  17 #include "lldb/Target/ObjCLanguageRuntime.h"
  18 #include "lldb/Target/Process.h"
  19 #include "lldb/Target/Thread.h"
  20 #include "lldb/Target/ThreadPlanRunToAddress.h"
  21 #include "lldb/Target/ThreadPlanStepOut.h"
  22 #include "lldb/Utility/Log.h"
  23
  24 using namespace lldb;
  25 using namespace lldb_private;
  26
  27 //----------------------------------------------------------------------
  28 // ThreadPlanStepThroughObjCTrampoline constructor
  29 //----------------------------------------------------------------------
  30 AppleThreadPlanStepThroughObjCTrampoline::
  31     AppleThreadPlanStepThroughObjCTrampoline(
  32         Thread &thread, AppleObjCTrampolineHandler *trampoline_handler,
  33         ValueList &input_values, lldb::addr_t isa_addr, lldb::addr_t sel_addr,
  34         bool stop_others)
  35     : ThreadPlan(ThreadPlan::eKindGeneric,
  36                  "MacOSX Step through ObjC Trampoline", thread, eVoteNoOpinion,
  37                  eVoteNoOpinion),
  38       m_trampoline_handler(trampoline_handler),
  39       m_args_addr(LLDB_INVALID_ADDRESS), m_input_values(input_values),
  40       m_isa_addr(isa_addr), m_sel_addr(sel_addr), m_impl_function(NULL),
  41       m_stop_others(stop_others) {}
  42
  43 //----------------------------------------------------------------------
  44 // Destructor
  45 //----------------------------------------------------------------------
  46 AppleThreadPlanStepThroughObjCTrampoline::
  47     ~AppleThreadPlanStepThroughObjCTrampoline() {}
  48
  49 void AppleThreadPlanStepThroughObjCTrampoline::DidPush() {
  50   // Setting up the memory space for the called function text might require
  51   // allocations, i.e. a nested function call.  This needs to be done as a
  52   // PreResumeAction.
  53   m_thread.GetProcess()->AddPreResumeAction(PreResumeInitializeFunctionCaller,
  54                                             (void *)this);
  55 }
  56
  57 bool AppleThreadPlanStepThroughObjCTrampoline::InitializeFunctionCaller() {
  58   if (!m_func_sp) {
  59     DiagnosticManager diagnostics;
  60     m_args_addr =
  61         m_trampoline_handler->SetupDispatchFunction(m_thread, m_input_values);
  62
  63     if (m_args_addr == LLDB_INVALID_ADDRESS) {
  64       return false;
  65     }
  66     m_impl_function =
  67         m_trampoline_handler->GetLookupImplementationFunctionCaller();
  68     ExecutionContext exc_ctx;
  69     EvaluateExpressionOptions options;
  70     options.SetUnwindOnError(true);
  71     options.SetIgnoreBreakpoints(true);
  72     options.SetStopOthers(m_stop_others);
  73     m_thread.CalculateExecutionContext(exc_ctx);
  74     m_func_sp = m_impl_function->GetThreadPlanToCallFunction(
  75         exc_ctx, m_args_addr, options, diagnostics);
  76     m_func_sp->SetOkayToDiscard(true);
  77     m_thread.QueueThreadPlan(m_func_sp, false);
  78   }
  79   return true;
  80 }
  81
  82 bool AppleThreadPlanStepThroughObjCTrampoline::
  83     PreResumeInitializeFunctionCaller(void *void_myself) {
  84   AppleThreadPlanStepThroughObjCTrampoline *myself =
  85       static_cast<AppleThreadPlanStepThroughObjCTrampoline *>(void_myself);
  86   return myself->InitializeFunctionCaller();
  87 }
  88
  89 void AppleThreadPlanStepThroughObjCTrampoline::GetDescription(
  90     Stream *s, lldb::DescriptionLevel level) {
  91   if (level == lldb::eDescriptionLevelBrief)
  92     s->Printf("Step through ObjC trampoline");
  93   else {
  94     s->Printf("Stepping to implementation of ObjC method - obj: 0x%llx, isa: "
  95               "0x%" PRIx64 ", sel: 0x%" PRIx64,
  96               m_input_values.GetValueAtIndex(0)->GetScalar().ULongLong(),
  97               m_isa_addr, m_sel_addr);
  98   }
  99 }
 100
 101 bool AppleThreadPlanStepThroughObjCTrampoline::ValidatePlan(Stream *error) {
 102   return true;
 103 }
 104
 105 bool AppleThreadPlanStepThroughObjCTrampoline::DoPlanExplainsStop(
 106     Event *event_ptr) {
 107   // If we get asked to explain the stop it will be because something went
 108   // wrong (like the implementation for selector function crashed...  We're
 109   // going to figure out what to do about that, so we do explain the stop.
 110   return true;
 111 }
 112
 113 lldb::StateType AppleThreadPlanStepThroughObjCTrampoline::GetPlanRunState() {
 114   return eStateRunning;
 115 }
 116
 117 bool AppleThreadPlanStepThroughObjCTrampoline::ShouldStop(Event *event_ptr) {
 118   // First stage: we are still handling the "call a function to get the target
 119   // of the dispatch"
 120   if (m_func_sp) {
 121     if (!m_func_sp->IsPlanComplete()) {
 122       return false;
 123     } else {
 124       if (!m_func_sp->PlanSucceeded()) {
 125         SetPlanComplete(false);
 126         return true;
 127       }
 128       m_func_sp.reset();
 129     }
 130   }
 131
 132   // Second stage, if all went well with the function calling, then fetch the
 133   // target address, and queue up a "run to that address" plan.
 134   if (!m_run_to_sp) {
 135     Value target_addr_value;
 136     ExecutionContext exc_ctx;
 137     m_thread.CalculateExecutionContext(exc_ctx);
 138     m_impl_function->FetchFunctionResults(exc_ctx, m_args_addr,
 139                                           target_addr_value);
 140     m_impl_function->DeallocateFunctionResults(exc_ctx, m_args_addr);
 141     lldb::addr_t target_addr = target_addr_value.GetScalar().ULongLong();
 142     Address target_so_addr;
 143     target_so_addr.SetOpcodeLoadAddress(target_addr, exc_ctx.GetTargetPtr());
 144     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
 145     if (target_addr == 0) {
 146       if (log)
 147         log->Printf("Got target implementation of 0x0, stopping.");
 148       SetPlanComplete();
 149       return true;
 150     }
 151     if (m_trampoline_handler->AddrIsMsgForward(target_addr)) {
 152       if (log)
 153         log->Printf(
 154             "Implementation lookup returned msgForward function: 0x%" PRIx64
 155             ", stopping.",
 156             target_addr);
 157
 158       SymbolContext sc = m_thread.GetStackFrameAtIndex(0)->GetSymbolContext(
 159           eSymbolContextEverything);
 160       Status status;
 161       const bool abort_other_plans = false;
 162       const bool first_insn = true;
 163       const uint32_t frame_idx = 0;
 164       m_run_to_sp = m_thread.QueueThreadPlanForStepOutNoShouldStop(
 165           abort_other_plans, &sc, first_insn, m_stop_others, eVoteNoOpinion,
 166           eVoteNoOpinion, frame_idx, status);
 167       if (m_run_to_sp && status.Success())
 168         m_run_to_sp->SetPrivate(true);
 169       return false;
 170     }
 171
 172     if (log)
 173       log->Printf("Running to ObjC method implementation: 0x%" PRIx64,
 174                   target_addr);
 175
 176     ObjCLanguageRuntime *objc_runtime =
 177         GetThread().GetProcess()->GetObjCLanguageRuntime();
 178     assert(objc_runtime != NULL);
 179     objc_runtime->AddToMethodCache(m_isa_addr, m_sel_addr, target_addr);
 180     if (log)
 181       log->Printf("Adding {isa-addr=0x%" PRIx64 ", sel-addr=0x%" PRIx64
 182                   "} = addr=0x%" PRIx64 " to cache.",
 183                   m_isa_addr, m_sel_addr, target_addr);
 184
 185     // Extract the target address from the value:
 186
 187     m_run_to_sp.reset(
 188         new ThreadPlanRunToAddress(m_thread, target_so_addr, m_stop_others));
 189     m_thread.QueueThreadPlan(m_run_to_sp, false);
 190     m_run_to_sp->SetPrivate(true);
 191     return false;
 192   } else if (m_thread.IsThreadPlanDone(m_run_to_sp.get())) {
 193     // Third stage, work the run to target plan.
 194     SetPlanComplete();
 195     return true;
 196   }
 197   return false;
 198 }
 199
 200 // The base class MischiefManaged does some cleanup - so you have to call it in
 201 // your MischiefManaged derived class.
 202 bool AppleThreadPlanStepThroughObjCTrampoline::MischiefManaged() {
 203   return IsPlanComplete();
 204 }
 205
 206 bool AppleThreadPlanStepThroughObjCTrampoline::WillStop() { return true; }