| //===-- ObjCTrampolineHandler.cpp ----------------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "ObjCTrampolineHandler.h" |
| |
| // C Includes |
| // C++ Includes |
| // Other libraries and framework includes |
| // Project includes |
| #include "lldb/Core/Module.h" |
| #include "lldb/Core/ConstString.h" |
| #include "lldb/Core/FileSpec.h" |
| #include "lldb/Target/Thread.h" |
| #include "lldb/Target/RegisterContext.h" |
| #include "lldb/Target/Target.h" |
| #include "lldb/Target/Process.h" |
| #include "lldb/Core/Value.h" |
| #include "lldb/Symbol/ClangASTContext.h" |
| #include "lldb/Expression/ClangFunction.h" |
| #include "lldb/Core/Log.h" |
| #include "lldb/Target/ExecutionContext.h" |
| #include "ThreadPlanStepThroughObjCTrampoline.h" |
| #include "lldb/Target/ThreadPlanRunToAddress.h" |
| |
| using namespace lldb; |
| using namespace lldb_private; |
| |
| const ObjCTrampolineHandler::DispatchFunction |
| ObjCTrampolineHandler::g_dispatch_functions[] = |
| { |
| // NAME STRET SUPER FIXUP TYPE |
| {"objc_msgSend", false, false, ObjCTrampolineHandler::DispatchFunction::eFixUpNone }, |
| {"objc_msgSend_fixup", false, false, ObjCTrampolineHandler::DispatchFunction::eFixUpToFix }, |
| {"objc_msgSend_fixedup", false, false, ObjCTrampolineHandler::DispatchFunction::eFixUpFixed }, |
| {"objc_msgSend_stret", true, false, ObjCTrampolineHandler::DispatchFunction::eFixUpNone }, |
| {"objc_msgSend_stret_fixup", true, false, ObjCTrampolineHandler::DispatchFunction::eFixUpToFix }, |
| {"objc_msgSend_stret_fixedup", true, false, ObjCTrampolineHandler::DispatchFunction::eFixUpFixed }, |
| {"objc_msgSend_fpret", false, false, ObjCTrampolineHandler::DispatchFunction::eFixUpNone }, |
| {"objc_msgSend_fpret_fixup", false, false, ObjCTrampolineHandler::DispatchFunction::eFixUpToFix }, |
| {"objc_msgSend_fpret_fixedup", false, false, ObjCTrampolineHandler::DispatchFunction::eFixUpFixed }, |
| {"objc_msgSend_fp2ret", false, false, ObjCTrampolineHandler::DispatchFunction::eFixUpNone }, |
| {"objc_msgSend_fp2ret_fixup", false, false, ObjCTrampolineHandler::DispatchFunction::eFixUpToFix }, |
| {"objc_msgSend_fp2ret_fixedup", false, false, ObjCTrampolineHandler::DispatchFunction::eFixUpFixed }, |
| {"objc_msgSendSuper", false, true, ObjCTrampolineHandler::DispatchFunction::eFixUpNone }, |
| {"objc_msgSendSuper_stret", true, true, ObjCTrampolineHandler::DispatchFunction::eFixUpNone }, |
| {"objc_msgSendSuper2", false, true, ObjCTrampolineHandler::DispatchFunction::eFixUpNone }, |
| {"objc_msgSendSuper2_fixup", false, true, ObjCTrampolineHandler::DispatchFunction::eFixUpToFix }, |
| {"objc_msgSendSuper2_fixedup", false, true, ObjCTrampolineHandler::DispatchFunction::eFixUpFixed }, |
| {"objc_msgSendSuper2_stret", true, true, ObjCTrampolineHandler::DispatchFunction::eFixUpNone }, |
| {"objc_msgSendSuper2_stret_fixup", true, true, ObjCTrampolineHandler::DispatchFunction::eFixUpToFix }, |
| {"objc_msgSendSuper2_stret_fixedup", true, true, ObjCTrampolineHandler::DispatchFunction::eFixUpFixed }, |
| {NULL} |
| }; |
| |
| bool |
| ObjCTrampolineHandler::ModuleIsObjCLibrary (const ModuleSP &module_sp) |
| { |
| const FileSpec &module_file_spec = module_sp->GetFileSpec(); |
| static ConstString ObjCName ("libobjc.A.dylib"); |
| |
| if (module_file_spec) |
| { |
| if (module_file_spec.GetFilename() == ObjCName) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| ObjCTrampolineHandler::ObjCTrampolineHandler (ProcessSP process_sp, ModuleSP objc_module) : |
| m_process_sp (process_sp), |
| m_objc_module_sp (objc_module), |
| m_impl_fn_addr (LLDB_INVALID_ADDRESS), |
| m_impl_stret_fn_addr (LLDB_INVALID_ADDRESS) |
| { |
| // Look up the known resolution functions: |
| |
| ConstString get_impl_name("class_getMethodImplementation"); |
| ConstString get_impl_stret_name("class_getMethodImplementation_stret"); |
| |
| const Symbol *class_getMethodImplementation = m_objc_module_sp->FindFirstSymbolWithNameAndType (get_impl_name, eSymbolTypeCode); |
| const Symbol *class_getMethodImplementation_stret = m_objc_module_sp->FindFirstSymbolWithNameAndType (get_impl_stret_name, eSymbolTypeCode); |
| |
| if (class_getMethodImplementation) |
| m_impl_fn_addr = class_getMethodImplementation->GetValue().GetLoadAddress(m_process_sp.get()); |
| if (class_getMethodImplementation_stret) |
| m_impl_stret_fn_addr = class_getMethodImplementation_stret->GetValue().GetLoadAddress(m_process_sp.get()); |
| |
| // FIXME: Do some kind of logging here. |
| if (m_impl_fn_addr == LLDB_INVALID_ADDRESS || m_impl_stret_fn_addr == LLDB_INVALID_ADDRESS) |
| return; |
| |
| // Look up the addresses for the objc dispatch functions and cache them. For now I'm inspecting the symbol |
| // names dynamically to figure out how to dispatch to them. If it becomes more complicated than this we can |
| // turn the g_dispatch_functions char * array into a template table, and populate the DispatchFunction map |
| // from there. |
| |
| for (int i = 0; g_dispatch_functions[i].name != NULL; i++) |
| { |
| ConstString name_const_str(g_dispatch_functions[i].name); |
| const Symbol *msgSend_symbol = m_objc_module_sp->FindFirstSymbolWithNameAndType (name_const_str, eSymbolTypeCode); |
| if (msgSend_symbol) |
| { |
| // FixMe: Make g_dispatch_functions static table of DisptachFunctions, and have the map be address->index. |
| // Problem is we also need to lookup the dispatch function. For now we could have a side table of stret & non-stret |
| // dispatch functions. If that's as complex as it gets, we're fine. |
| |
| lldb::addr_t sym_addr = msgSend_symbol->GetValue().GetLoadAddress(m_process_sp.get()); |
| |
| m_msgSend_map.insert(std::pair<lldb::addr_t, int>(sym_addr, i)); |
| } |
| } |
| } |
| |
| ThreadPlanSP |
| ObjCTrampolineHandler::GetStepThroughDispatchPlan (Thread &thread, bool stop_others) |
| { |
| ThreadPlanSP ret_plan_sp; |
| lldb::addr_t curr_pc = thread.GetRegisterContext()->GetPC(); |
| |
| MsgsendMap::iterator pos; |
| pos = m_msgSend_map.find (curr_pc); |
| if (pos != m_msgSend_map.end()) |
| { |
| Log *log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP); |
| |
| const DispatchFunction *this_dispatch = &g_dispatch_functions[(*pos).second]; |
| |
| lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); |
| |
| Process *process = thread.CalculateProcess(); |
| const ABI *abi = process->GetABI(); |
| if (abi == NULL) |
| return ret_plan_sp; |
| |
| Target *target = thread.CalculateTarget(); |
| |
| // FIXME: Since neither the value nor the Clang QualType know their ASTContext, |
| // we have to make sure the type we put in our value list comes from the same ASTContext |
| // the ABI will use to get the argument values. THis is the bottom-most frame's module. |
| |
| ClangASTContext *clang_ast_context = target->GetScratchClangASTContext(); |
| ValueList argument_values; |
| Value input_value; |
| void *clang_void_ptr_type = clang_ast_context->GetVoidPtrType(false); |
| input_value.SetValueType (Value::eValueTypeScalar); |
| input_value.SetContext (Value::eContextTypeOpaqueClangQualType, clang_void_ptr_type); |
| |
| int obj_index; |
| int sel_index; |
| |
| // If this is a struct return dispatch, then the first argument is the |
| // return struct pointer, and the object is the second, and the selector is the third. |
| // Otherwise the object is the first and the selector the second. |
| if (this_dispatch->stret_return) |
| { |
| obj_index = 1; |
| sel_index = 2; |
| argument_values.PushValue(input_value); |
| argument_values.PushValue(input_value); |
| argument_values.PushValue(input_value); |
| } |
| else |
| { |
| obj_index = 0; |
| sel_index = 1; |
| argument_values.PushValue(input_value); |
| argument_values.PushValue(input_value); |
| } |
| |
| |
| bool success = abi->GetArgumentValues (thread, argument_values); |
| if (!success) |
| return ret_plan_sp; |
| |
| // Okay, the first value here is the object, we actually want the class of that object. |
| // For now we're just going with the ISA. |
| // FIXME: This should really be the return value of [object class] to properly handle KVO interposition. |
| |
| Value isa_value(*(argument_values.GetValueAtIndex(obj_index))); |
| |
| // This is a little cheesy, but since object->isa is the first field, |
| // making the object value a load address value and resolving it will get |
| // the pointer sized data pointed to by that value... |
| ExecutionContext exec_ctx; |
| thread.Calculate (exec_ctx); |
| |
| isa_value.SetValueType(Value::eValueTypeLoadAddress); |
| isa_value.ResolveValue(&exec_ctx, clang_ast_context->getASTContext()); |
| |
| if (this_dispatch->fixedup == DispatchFunction::eFixUpFixed) |
| { |
| // For the FixedUp method the Selector is actually a pointer to a |
| // structure, the second field of which is the selector number. |
| Value *sel_value = argument_values.GetValueAtIndex(sel_index); |
| sel_value->GetScalar() += process->GetAddressByteSize(); |
| sel_value->SetValueType(Value::eValueTypeLoadAddress); |
| sel_value->ResolveValue(&exec_ctx, clang_ast_context->getASTContext()); |
| } |
| else if (this_dispatch->fixedup == DispatchFunction::eFixUpToFix) |
| { |
| // FIXME: If the method dispatch is not "fixed up" then the selector is actually a |
| // pointer to the string name of the selector. We need to look that up... |
| // For now I'm going to punt on that and just return no plan. |
| if (log) |
| log->Printf ("Punting on stepping into un-fixed-up method dispatch."); |
| return ret_plan_sp; |
| } |
| |
| // FIXME: If this is a dispatch to the super-class, we need to get the super-class from |
| // the class, and disaptch to that instead. |
| // But for now I just punt and return no plan. |
| if (this_dispatch->is_super) |
| { |
| if (log) |
| log->Printf ("Punting on stepping into super method dispatch."); |
| return ret_plan_sp; |
| } |
| |
| ValueList dispatch_values; |
| dispatch_values.PushValue (isa_value); |
| dispatch_values.PushValue(*(argument_values.GetValueAtIndex(sel_index))); |
| |
| if (log) |
| { |
| log->Printf("Resolving method call for class - 0x%llx and selector - 0x%llx", |
| dispatch_values.GetValueAtIndex(0)->GetScalar().ULongLong(), |
| dispatch_values.GetValueAtIndex(1)->GetScalar().ULongLong()); |
| } |
| |
| lldb::addr_t impl_addr = LookupInCache (dispatch_values.GetValueAtIndex(0)->GetScalar().ULongLong(), |
| dispatch_values.GetValueAtIndex(1)->GetScalar().ULongLong()); |
| |
| if (impl_addr == LLDB_INVALID_ADDRESS) |
| { |
| |
| Address resolve_address(NULL, this_dispatch->stret_return ? m_impl_stret_fn_addr : m_impl_fn_addr); |
| |
| StreamString errors; |
| { |
| // Scope for mutex locker: |
| Mutex::Locker (m_impl_function_mutex); |
| if (!m_impl_function.get()) |
| { |
| m_impl_function.reset(new ClangFunction(process->GetTargetTriple().GetCString(), |
| clang_ast_context, |
| clang_void_ptr_type, |
| resolve_address, |
| dispatch_values)); |
| |
| unsigned num_errors = m_impl_function->CompileFunction(errors); |
| if (num_errors) |
| { |
| Log *log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP); |
| if (log) |
| log->Printf ("Error compiling function: \"%s\".", errors.GetData()); |
| return ret_plan_sp; |
| } |
| |
| errors.Clear(); |
| if (!m_impl_function->WriteFunctionWrapper(exec_ctx, errors)) |
| { |
| Log *log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP); |
| if (log) |
| log->Printf ("Error Inserting function: \"%s\".", errors.GetData()); |
| return ret_plan_sp; |
| } |
| } |
| |
| } |
| |
| errors.Clear(); |
| |
| // Now write down the argument values for this call. |
| lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; |
| if (!m_impl_function->WriteFunctionArguments (exec_ctx, args_addr, resolve_address, dispatch_values, errors)) |
| return ret_plan_sp; |
| |
| ret_plan_sp.reset (new ThreadPlanStepThroughObjCTrampoline (thread, this, args_addr, |
| argument_values.GetValueAtIndex(0)->GetScalar().ULongLong(), |
| dispatch_values.GetValueAtIndex(0)->GetScalar().ULongLong(), |
| dispatch_values.GetValueAtIndex(1)->GetScalar().ULongLong(), |
| stop_others)); |
| } |
| else |
| { |
| if (log) |
| log->Printf ("Found implementation address in cache: 0x%llx", impl_addr); |
| |
| ret_plan_sp.reset (new ThreadPlanRunToAddress (thread, impl_addr, stop_others)); |
| } |
| } |
| |
| return ret_plan_sp; |
| } |
| |
| void |
| ObjCTrampolineHandler::AddToCache (lldb::addr_t class_addr, lldb::addr_t selector, lldb::addr_t impl_addr) |
| { |
| Log *log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP); |
| if (log) |
| { |
| log->Printf ("Caching: class 0x%llx selector 0x%llx implementation 0x%llx.", class_addr, selector, impl_addr); |
| } |
| m_impl_cache.insert (std::pair<ClassAndSel,lldb::addr_t> (ClassAndSel(class_addr, selector), impl_addr)); |
| } |
| |
| lldb::addr_t |
| ObjCTrampolineHandler::LookupInCache (lldb::addr_t class_addr, lldb::addr_t selector) |
| { |
| MsgImplMap::iterator pos, end = m_impl_cache.end(); |
| pos = m_impl_cache.find (ClassAndSel(class_addr, selector)); |
| if (pos != end) |
| return (*pos).second; |
| return LLDB_INVALID_ADDRESS; |
| } |
| |
| ClangFunction * |
| ObjCTrampolineHandler::GetLookupImplementationWrapperFunction () |
| { |
| return m_impl_function.get(); |
| } |