AppleThreadPlanStepThroughObjCTrampoline.cpp revision 341825 
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// C Includes
12// C++ Includes
13// Other libraries and framework includes
14// Project includes
15#include "AppleThreadPlanStepThroughObjCTrampoline.h"
16#include "AppleObjCTrampolineHandler.h"
17#include "lldb/Expression/DiagnosticManager.h"
18#include "lldb/Expression/FunctionCaller.h"
19#include "lldb/Expression/UtilityFunction.h"
20#include "lldb/Target/ExecutionContext.h"
21#include "lldb/Target/ObjCLanguageRuntime.h"
22#include "lldb/Target/Process.h"
23#include "lldb/Target/Thread.h"
24#include "lldb/Target/ThreadPlanRunToAddress.h"
25#include "lldb/Target/ThreadPlanStepOut.h"
26#include "lldb/Utility/Log.h"
27
28using namespace lldb;
29using namespace lldb_private;
30
31//----------------------------------------------------------------------
32// ThreadPlanStepThroughObjCTrampoline constructor
33//----------------------------------------------------------------------
34AppleThreadPlanStepThroughObjCTrampoline::
35    AppleThreadPlanStepThroughObjCTrampoline(
36        Thread &thread, AppleObjCTrampolineHandler *trampoline_handler,
37        ValueList &input_values, lldb::addr_t isa_addr, lldb::addr_t sel_addr,
38        bool stop_others)
39    : ThreadPlan(ThreadPlan::eKindGeneric,
40                 "MacOSX Step through ObjC Trampoline", thread, eVoteNoOpinion,
41                 eVoteNoOpinion),
42      m_trampoline_handler(trampoline_handler),
43      m_args_addr(LLDB_INVALID_ADDRESS), m_input_values(input_values),
44      m_isa_addr(isa_addr), m_sel_addr(sel_addr), m_impl_function(NULL),
45      m_stop_others(stop_others) {}
46
47//----------------------------------------------------------------------
48// Destructor
49//----------------------------------------------------------------------
50AppleThreadPlanStepThroughObjCTrampoline::
51    ~AppleThreadPlanStepThroughObjCTrampoline() {}
52
53void AppleThreadPlanStepThroughObjCTrampoline::DidPush() {
54  // Setting up the memory space for the called function text might require
55  // allocations, i.e. a nested function call.  This needs to be done as a
56  // PreResumeAction.
57  m_thread.GetProcess()->AddPreResumeAction(PreResumeInitializeFunctionCaller,
58                                            (void *)this);
59}
60
61bool AppleThreadPlanStepThroughObjCTrampoline::InitializeFunctionCaller() {
62  if (!m_func_sp) {
63    DiagnosticManager diagnostics;
64    m_args_addr =
65        m_trampoline_handler->SetupDispatchFunction(m_thread, m_input_values);
66
67    if (m_args_addr == LLDB_INVALID_ADDRESS) {
68      return false;
69    }
70    m_impl_function =
71        m_trampoline_handler->GetLookupImplementationFunctionCaller();
72    ExecutionContext exc_ctx;
73    EvaluateExpressionOptions options;
74    options.SetUnwindOnError(true);
75    options.SetIgnoreBreakpoints(true);
76    options.SetStopOthers(m_stop_others);
77    m_thread.CalculateExecutionContext(exc_ctx);
78    m_func_sp = m_impl_function->GetThreadPlanToCallFunction(
79        exc_ctx, m_args_addr, options, diagnostics);
80    m_func_sp->SetOkayToDiscard(true);
81    m_thread.QueueThreadPlan(m_func_sp, false);
82  }
83  return true;
84}
85
86bool AppleThreadPlanStepThroughObjCTrampoline::
87    PreResumeInitializeFunctionCaller(void *void_myself) {
88  AppleThreadPlanStepThroughObjCTrampoline *myself =
89      static_cast<AppleThreadPlanStepThroughObjCTrampoline *>(void_myself);
90  return myself->InitializeFunctionCaller();
91}
92
93void AppleThreadPlanStepThroughObjCTrampoline::GetDescription(
94    Stream *s, lldb::DescriptionLevel level) {
95  if (level == lldb::eDescriptionLevelBrief)
96    s->Printf("Step through ObjC trampoline");
97  else {
98    s->Printf("Stepping to implementation of ObjC method - obj: 0x%llx, isa: "
99              "0x%" PRIx64 ", sel: 0x%" PRIx64,
100              m_input_values.GetValueAtIndex(0)->GetScalar().ULongLong(),
101              m_isa_addr, m_sel_addr);
102  }
103}
104
105bool AppleThreadPlanStepThroughObjCTrampoline::ValidatePlan(Stream *error) {
106  return true;
107}
108
109bool AppleThreadPlanStepThroughObjCTrampoline::DoPlanExplainsStop(
110    Event *event_ptr) {
111  // If we get asked to explain the stop it will be because something went
112  // wrong (like the implementation for selector function crashed...  We're
113  // going to figure out what to do about that, so we do explain the stop.
114  return true;
115}
116
117lldb::StateType AppleThreadPlanStepThroughObjCTrampoline::GetPlanRunState() {
118  return eStateRunning;
119}
120
121bool AppleThreadPlanStepThroughObjCTrampoline::ShouldStop(Event *event_ptr) {
122  // First stage: we are still handling the "call a function to get the target
123  // of the dispatch"
124  if (m_func_sp) {
125    if (!m_func_sp->IsPlanComplete()) {
126      return false;
127    } else {
128      if (!m_func_sp->PlanSucceeded()) {
129        SetPlanComplete(false);
130        return true;
131      }
132      m_func_sp.reset();
133    }
134  }
135
136  // Second stage, if all went well with the function calling, then fetch the
137  // target address, and queue up a "run to that address" plan.
138  if (!m_run_to_sp) {
139    Value target_addr_value;
140    ExecutionContext exc_ctx;
141    m_thread.CalculateExecutionContext(exc_ctx);
142    m_impl_function->FetchFunctionResults(exc_ctx, m_args_addr,
143                                          target_addr_value);
144    m_impl_function->DeallocateFunctionResults(exc_ctx, m_args_addr);
145    lldb::addr_t target_addr = target_addr_value.GetScalar().ULongLong();
146    Address target_so_addr;
147    target_so_addr.SetOpcodeLoadAddress(target_addr, exc_ctx.GetTargetPtr());
148    Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
149    if (target_addr == 0) {
150      if (log)
151        log->Printf("Got target implementation of 0x0, stopping.");
152      SetPlanComplete();
153      return true;
154    }
155    if (m_trampoline_handler->AddrIsMsgForward(target_addr)) {
156      if (log)
157        log->Printf(
158            "Implementation lookup returned msgForward function: 0x%" PRIx64
159            ", stopping.",
160            target_addr);
161
162      SymbolContext sc = m_thread.GetStackFrameAtIndex(0)->GetSymbolContext(
163          eSymbolContextEverything);
164      const bool abort_other_plans = false;
165      const bool first_insn = true;
166      const uint32_t frame_idx = 0;
167      m_run_to_sp = m_thread.QueueThreadPlanForStepOutNoShouldStop(
168          abort_other_plans, &sc, first_insn, m_stop_others, eVoteNoOpinion,
169          eVoteNoOpinion, frame_idx);
170      m_run_to_sp->SetPrivate(true);
171      return false;
172    }
173
174    if (log)
175      log->Printf("Running to ObjC method implementation: 0x%" PRIx64,
176                  target_addr);
177
178    ObjCLanguageRuntime *objc_runtime =
179        GetThread().GetProcess()->GetObjCLanguageRuntime();
180    assert(objc_runtime != NULL);
181    objc_runtime->AddToMethodCache(m_isa_addr, m_sel_addr, target_addr);
182    if (log)
183      log->Printf("Adding {isa-addr=0x%" PRIx64 ", sel-addr=0x%" PRIx64
184                  "} = addr=0x%" PRIx64 " to cache.",
185                  m_isa_addr, m_sel_addr, target_addr);
186
187    // Extract the target address from the value:
188
189    m_run_to_sp.reset(
190        new ThreadPlanRunToAddress(m_thread, target_so_addr, m_stop_others));
191    m_thread.QueueThreadPlan(m_run_to_sp, false);
192    m_run_to_sp->SetPrivate(true);
193    return false;
194  } else if (m_thread.IsThreadPlanDone(m_run_to_sp.get())) {
195    // Third stage, work the run to target plan.
196    SetPlanComplete();
197    return true;
198  }
199  return false;
200}
201
202// The base class MischiefManaged does some cleanup - so you have to call it in
203// your MischiefManaged derived class.
204bool AppleThreadPlanStepThroughObjCTrampoline::MischiefManaged() {
205  if (IsPlanComplete())
206    return true;
207  else
208    return false;
209}
210
211bool AppleThreadPlanStepThroughObjCTrampoline::WillStop() { return true; }
212