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//===-- AppleThreadPlanStepThroughObjCTrampoline.cpp
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "AppleThreadPlanStepThroughObjCTrampoline.h"
#include "AppleObjCTrampolineHandler.h"
#include "lldb/Expression/DiagnosticManager.h"
#include "lldb/Expression/FunctionCaller.h"
#include "lldb/Expression/UtilityFunction.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/Thread.h"
#include "lldb/Target/ThreadPlanRunToAddress.h"
#include "lldb/Target/ThreadPlanStepOut.h"
#include "lldb/Utility/Log.h"
#include "Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.h"
#include <memory>
using namespace lldb;
using namespace lldb_private;
// ThreadPlanStepThroughObjCTrampoline constructor
AppleThreadPlanStepThroughObjCTrampoline::
AppleThreadPlanStepThroughObjCTrampoline(
Thread &thread, AppleObjCTrampolineHandler *trampoline_handler,
ValueList &input_values, lldb::addr_t isa_addr, lldb::addr_t sel_addr,
bool stop_others)
: ThreadPlan(ThreadPlan::eKindGeneric,
"MacOSX Step through ObjC Trampoline", thread, eVoteNoOpinion,
eVoteNoOpinion),
m_trampoline_handler(trampoline_handler),
m_args_addr(LLDB_INVALID_ADDRESS), m_input_values(input_values),
m_isa_addr(isa_addr), m_sel_addr(sel_addr), m_impl_function(nullptr),
m_stop_others(stop_others) {}
// Destructor
AppleThreadPlanStepThroughObjCTrampoline::
~AppleThreadPlanStepThroughObjCTrampoline() {}
void AppleThreadPlanStepThroughObjCTrampoline::DidPush() {
// Setting up the memory space for the called function text might require
// allocations, i.e. a nested function call. This needs to be done as a
// PreResumeAction.
m_thread.GetProcess()->AddPreResumeAction(PreResumeInitializeFunctionCaller,
(void *)this);
}
bool AppleThreadPlanStepThroughObjCTrampoline::InitializeFunctionCaller() {
if (!m_func_sp) {
DiagnosticManager diagnostics;
m_args_addr =
m_trampoline_handler->SetupDispatchFunction(m_thread, m_input_values);
if (m_args_addr == LLDB_INVALID_ADDRESS) {
return false;
}
m_impl_function =
m_trampoline_handler->GetLookupImplementationFunctionCaller();
ExecutionContext exc_ctx;
EvaluateExpressionOptions options;
options.SetUnwindOnError(true);
options.SetIgnoreBreakpoints(true);
options.SetStopOthers(m_stop_others);
m_thread.CalculateExecutionContext(exc_ctx);
m_func_sp = m_impl_function->GetThreadPlanToCallFunction(
exc_ctx, m_args_addr, options, diagnostics);
m_func_sp->SetOkayToDiscard(true);
m_thread.QueueThreadPlan(m_func_sp, false);
}
return true;
}
bool AppleThreadPlanStepThroughObjCTrampoline::
PreResumeInitializeFunctionCaller(void *void_myself) {
AppleThreadPlanStepThroughObjCTrampoline *myself =
static_cast<AppleThreadPlanStepThroughObjCTrampoline *>(void_myself);
return myself->InitializeFunctionCaller();
}
void AppleThreadPlanStepThroughObjCTrampoline::GetDescription(
Stream *s, lldb::DescriptionLevel level) {
if (level == lldb::eDescriptionLevelBrief)
s->Printf("Step through ObjC trampoline");
else {
s->Printf("Stepping to implementation of ObjC method - obj: 0x%llx, isa: "
"0x%" PRIx64 ", sel: 0x%" PRIx64,
m_input_values.GetValueAtIndex(0)->GetScalar().ULongLong(),
m_isa_addr, m_sel_addr);
}
}
bool AppleThreadPlanStepThroughObjCTrampoline::ValidatePlan(Stream *error) {
return true;
}
bool AppleThreadPlanStepThroughObjCTrampoline::DoPlanExplainsStop(
Event *event_ptr) {
// If we get asked to explain the stop it will be because something went
// wrong (like the implementation for selector function crashed... We're
// going to figure out what to do about that, so we do explain the stop.
return true;
}
lldb::StateType AppleThreadPlanStepThroughObjCTrampoline::GetPlanRunState() {
return eStateRunning;
}
bool AppleThreadPlanStepThroughObjCTrampoline::ShouldStop(Event *event_ptr) {
// First stage: we are still handling the "call a function to get the target
// of the dispatch"
if (m_func_sp) {
if (!m_func_sp->IsPlanComplete()) {
return false;
} else {
if (!m_func_sp->PlanSucceeded()) {
SetPlanComplete(false);
return true;
}
m_func_sp.reset();
}
}
// Second stage, if all went well with the function calling, then fetch the
// target address, and queue up a "run to that address" plan.
if (!m_run_to_sp) {
Value target_addr_value;
ExecutionContext exc_ctx;
m_thread.CalculateExecutionContext(exc_ctx);
m_impl_function->FetchFunctionResults(exc_ctx, m_args_addr,
target_addr_value);
m_impl_function->DeallocateFunctionResults(exc_ctx, m_args_addr);
lldb::addr_t target_addr = target_addr_value.GetScalar().ULongLong();
Address target_so_addr;
target_so_addr.SetOpcodeLoadAddress(target_addr, exc_ctx.GetTargetPtr());
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
if (target_addr == 0) {
if (log)
log->Printf("Got target implementation of 0x0, stopping.");
SetPlanComplete();
return true;
}
if (m_trampoline_handler->AddrIsMsgForward(target_addr)) {
if (log)
log->Printf(
"Implementation lookup returned msgForward function: 0x%" PRIx64
", stopping.",
target_addr);
SymbolContext sc = m_thread.GetStackFrameAtIndex(0)->GetSymbolContext(
eSymbolContextEverything);
Status status;
const bool abort_other_plans = false;
const bool first_insn = true;
const uint32_t frame_idx = 0;
m_run_to_sp = m_thread.QueueThreadPlanForStepOutNoShouldStop(
abort_other_plans, &sc, first_insn, m_stop_others, eVoteNoOpinion,
eVoteNoOpinion, frame_idx, status);
if (m_run_to_sp && status.Success())
m_run_to_sp->SetPrivate(true);
return false;
}
if (log)
log->Printf("Running to ObjC method implementation: 0x%" PRIx64,
target_addr);
ObjCLanguageRuntime *objc_runtime =
ObjCLanguageRuntime::Get(*GetThread().GetProcess());
assert(objc_runtime != nullptr);
objc_runtime->AddToMethodCache(m_isa_addr, m_sel_addr, target_addr);
if (log)
log->Printf("Adding {isa-addr=0x%" PRIx64 ", sel-addr=0x%" PRIx64
"} = addr=0x%" PRIx64 " to cache.",
m_isa_addr, m_sel_addr, target_addr);
// Extract the target address from the value:
m_run_to_sp = std::make_shared<ThreadPlanRunToAddress>(
m_thread, target_so_addr, m_stop_others);
m_thread.QueueThreadPlan(m_run_to_sp, false);
m_run_to_sp->SetPrivate(true);
return false;
} else if (m_thread.IsThreadPlanDone(m_run_to_sp.get())) {
// Third stage, work the run to target plan.
SetPlanComplete();
return true;
}
return false;
}
// The base class MischiefManaged does some cleanup - so you have to call it in
// your MischiefManaged derived class.
bool AppleThreadPlanStepThroughObjCTrampoline::MischiefManaged() {
return IsPlanComplete();
}
bool AppleThreadPlanStepThroughObjCTrampoline::WillStop() { return true; }
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