| //===-- AppleObjCTrampolineHandler.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 "AppleObjCTrampolineHandler.h" |
| #include "AppleThreadPlanStepThroughObjCTrampoline.h" |
| |
| #include "Plugins/TypeSystem/Clang/TypeSystemClang.h" |
| #include "lldb/Breakpoint/StoppointCallbackContext.h" |
| #include "lldb/Core/Debugger.h" |
| #include "lldb/Core/Module.h" |
| #include "lldb/Core/StreamFile.h" |
| #include "lldb/Core/Value.h" |
| #include "lldb/Expression/DiagnosticManager.h" |
| #include "lldb/Expression/FunctionCaller.h" |
| #include "lldb/Expression/UserExpression.h" |
| #include "lldb/Expression/UtilityFunction.h" |
| #include "lldb/Symbol/Symbol.h" |
| #include "lldb/Target/ABI.h" |
| #include "lldb/Target/ExecutionContext.h" |
| #include "lldb/Target/Process.h" |
| #include "lldb/Target/RegisterContext.h" |
| #include "lldb/Target/Target.h" |
| #include "lldb/Target/Thread.h" |
| #include "lldb/Target/ThreadPlanRunToAddress.h" |
| #include "lldb/Utility/ConstString.h" |
| #include "lldb/Utility/FileSpec.h" |
| #include "lldb/Utility/Log.h" |
| |
| #include "llvm/ADT/STLExtras.h" |
| |
| #include "Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.h" |
| |
| #include <memory> |
| |
| using namespace lldb; |
| using namespace lldb_private; |
| |
| const char *AppleObjCTrampolineHandler::g_lookup_implementation_function_name = |
| "__lldb_objc_find_implementation_for_selector"; |
| const char *AppleObjCTrampolineHandler:: |
| g_lookup_implementation_with_stret_function_code = |
| " \n\ |
| extern \"C\" \n\ |
| { \n\ |
| extern void *class_getMethodImplementation(void *objc_class, void *sel); \n\ |
| extern void *class_getMethodImplementation_stret(void *objc_class, \n\ |
| void *sel); \n\ |
| extern void * object_getClass (id object); \n\ |
| extern void * sel_getUid(char *name); \n\ |
| extern int printf(const char *format, ...); \n\ |
| } \n\ |
| extern \"C\" void * __lldb_objc_find_implementation_for_selector ( \n\ |
| void *object, \n\ |
| void *sel, \n\ |
| int is_stret, \n\ |
| int is_super, \n\ |
| int is_super2, \n\ |
| int is_fixup, \n\ |
| int is_fixed, \n\ |
| int debug) \n\ |
| { \n\ |
| struct __lldb_imp_return_struct \n\ |
| { \n\ |
| void *class_addr; \n\ |
| void *sel_addr; \n\ |
| void *impl_addr; \n\ |
| }; \n\ |
| \n\ |
| struct __lldb_objc_class { \n\ |
| void *isa; \n\ |
| void *super_ptr; \n\ |
| }; \n\ |
| struct __lldb_objc_super { \n\ |
| void *receiver; \n\ |
| struct __lldb_objc_class *class_ptr; \n\ |
| }; \n\ |
| struct __lldb_msg_ref { \n\ |
| void *dont_know; \n\ |
| void *sel; \n\ |
| }; \n\ |
| \n\ |
| struct __lldb_imp_return_struct return_struct; \n\ |
| \n\ |
| if (debug) \n\ |
| printf (\"\\n*** Called with obj: 0x%p sel: 0x%p is_stret: %d is_super: %d, \"\n\ |
| \"is_super2: %d, is_fixup: %d, is_fixed: %d\\n\", \n\ |
| object, sel, is_stret, is_super, is_super2, is_fixup, is_fixed);\n\ |
| if (is_super) \n\ |
| { \n\ |
| if (is_super2) \n\ |
| { \n\ |
| return_struct.class_addr = ((__lldb_objc_super *) object)->class_ptr->super_ptr;\n\ |
| } \n\ |
| else \n\ |
| { \n\ |
| return_struct.class_addr = ((__lldb_objc_super *) object)->class_ptr;\n\ |
| } \n\ |
| } \n\ |
| else \n\ |
| { \n\ |
| // This code seems a little funny, but has its reasons... \n\ |
| \n\ |
| // The call to [object class] is here because if this is a \n\ |
| // class, and has not been called into yet, we need to do \n\ |
| // something to force the class to initialize itself. \n\ |
| // Then the call to object_getClass will actually return the \n\ |
| // correct class, either the class if object is a class \n\ |
| // instance, or the meta-class if it is a class pointer. \n\ |
| void *class_ptr = (void *) [(id) object class]; \n\ |
| return_struct.class_addr = (id) object_getClass((id) object); \n\ |
| if (debug) \n\ |
| { \n\ |
| if (class_ptr == object) \n\ |
| { \n\ |
| printf (\"Found a class object, need to use the meta class %p -> %p\\n\",\n\ |
| class_ptr, return_struct.class_addr); \n\ |
| } \n\ |
| else \n\ |
| { \n\ |
| printf (\"[object class] returned: %p object_getClass: %p.\\n\", \n\ |
| class_ptr, return_struct.class_addr); \n\ |
| } \n\ |
| } \n\ |
| } \n\ |
| \n\ |
| if (is_fixup) \n\ |
| { \n\ |
| if (is_fixed) \n\ |
| { \n\ |
| return_struct.sel_addr = ((__lldb_msg_ref *) sel)->sel; \n\ |
| } \n\ |
| else \n\ |
| { \n\ |
| char *sel_name = (char *) ((__lldb_msg_ref *) sel)->sel; \n\ |
| return_struct.sel_addr = sel_getUid (sel_name); \n\ |
| if (debug) \n\ |
| printf (\"\\n*** Got fixed up selector: %p for name %s.\\n\",\n\ |
| return_struct.sel_addr, sel_name); \n\ |
| } \n\ |
| } \n\ |
| else \n\ |
| { \n\ |
| return_struct.sel_addr = sel; \n\ |
| } \n\ |
| \n\ |
| if (is_stret) \n\ |
| { \n\ |
| return_struct.impl_addr = \n\ |
| class_getMethodImplementation_stret (return_struct.class_addr, \n\ |
| return_struct.sel_addr); \n\ |
| } \n\ |
| else \n\ |
| { \n\ |
| return_struct.impl_addr = \n\ |
| class_getMethodImplementation (return_struct.class_addr, \n\ |
| return_struct.sel_addr); \n\ |
| } \n\ |
| if (debug) \n\ |
| printf (\"\\n*** Returning implementation: %p.\\n\", \n\ |
| return_struct.impl_addr); \n\ |
| \n\ |
| return return_struct.impl_addr; \n\ |
| } \n\ |
| "; |
| const char * |
| AppleObjCTrampolineHandler::g_lookup_implementation_no_stret_function_code = |
| " \n\ |
| extern \"C\" \n\ |
| { \n\ |
| extern void *class_getMethodImplementation(void *objc_class, void *sel); \n\ |
| extern void * object_getClass (id object); \n\ |
| extern void * sel_getUid(char *name); \n\ |
| extern int printf(const char *format, ...); \n\ |
| } \n\ |
| extern \"C\" void * __lldb_objc_find_implementation_for_selector (void *object, \n\ |
| void *sel, \n\ |
| int is_stret, \n\ |
| int is_super, \n\ |
| int is_super2, \n\ |
| int is_fixup, \n\ |
| int is_fixed, \n\ |
| int debug) \n\ |
| { \n\ |
| struct __lldb_imp_return_struct \n\ |
| { \n\ |
| void *class_addr; \n\ |
| void *sel_addr; \n\ |
| void *impl_addr; \n\ |
| }; \n\ |
| \n\ |
| struct __lldb_objc_class { \n\ |
| void *isa; \n\ |
| void *super_ptr; \n\ |
| }; \n\ |
| struct __lldb_objc_super { \n\ |
| void *receiver; \n\ |
| struct __lldb_objc_class *class_ptr; \n\ |
| }; \n\ |
| struct __lldb_msg_ref { \n\ |
| void *dont_know; \n\ |
| void *sel; \n\ |
| }; \n\ |
| \n\ |
| struct __lldb_imp_return_struct return_struct; \n\ |
| \n\ |
| if (debug) \n\ |
| printf (\"\\n*** Called with obj: 0x%p sel: 0x%p is_stret: %d is_super: %d, \" \n\ |
| \"is_super2: %d, is_fixup: %d, is_fixed: %d\\n\", \n\ |
| object, sel, is_stret, is_super, is_super2, is_fixup, is_fixed); \n\ |
| if (is_super) \n\ |
| { \n\ |
| if (is_super2) \n\ |
| { \n\ |
| return_struct.class_addr = ((__lldb_objc_super *) object)->class_ptr->super_ptr; \n\ |
| } \n\ |
| else \n\ |
| { \n\ |
| return_struct.class_addr = ((__lldb_objc_super *) object)->class_ptr; \n\ |
| } \n\ |
| } \n\ |
| else \n\ |
| { \n\ |
| // This code seems a little funny, but has its reasons... \n\ |
| // The call to [object class] is here because if this is a class, and has not been called into \n\ |
| // yet, we need to do something to force the class to initialize itself. \n\ |
| // Then the call to object_getClass will actually return the correct class, either the class \n\ |
| // if object is a class instance, or the meta-class if it is a class pointer. \n\ |
| void *class_ptr = (void *) [(id) object class]; \n\ |
| return_struct.class_addr = (id) object_getClass((id) object); \n\ |
| if (debug) \n\ |
| { \n\ |
| if (class_ptr == object) \n\ |
| { \n\ |
| printf (\"Found a class object, need to return the meta class %p -> %p\\n\", \n\ |
| class_ptr, return_struct.class_addr); \n\ |
| } \n\ |
| else \n\ |
| { \n\ |
| printf (\"[object class] returned: %p object_getClass: %p.\\n\", \n\ |
| class_ptr, return_struct.class_addr); \n\ |
| } \n\ |
| } \n\ |
| } \n\ |
| \n\ |
| if (is_fixup) \n\ |
| { \n\ |
| if (is_fixed) \n\ |
| { \n\ |
| return_struct.sel_addr = ((__lldb_msg_ref *) sel)->sel; \n\ |
| } \n\ |
| else \n\ |
| { \n\ |
| char *sel_name = (char *) ((__lldb_msg_ref *) sel)->sel; \n\ |
| return_struct.sel_addr = sel_getUid (sel_name); \n\ |
| if (debug) \n\ |
| printf (\"\\n*** Got fixed up selector: %p for name %s.\\n\",\n\ |
| return_struct.sel_addr, sel_name); \n\ |
| } \n\ |
| } \n\ |
| else \n\ |
| { \n\ |
| return_struct.sel_addr = sel; \n\ |
| } \n\ |
| \n\ |
| return_struct.impl_addr = \n\ |
| class_getMethodImplementation (return_struct.class_addr, \n\ |
| return_struct.sel_addr); \n\ |
| if (debug) \n\ |
| printf (\"\\n*** Returning implementation: 0x%p.\\n\", \n\ |
| return_struct.impl_addr); \n\ |
| \n\ |
| return return_struct.impl_addr; \n\ |
| } \n\ |
| "; |
| |
| AppleObjCTrampolineHandler::AppleObjCVTables::VTableRegion::VTableRegion( |
| AppleObjCVTables *owner, lldb::addr_t header_addr) |
| : m_valid(true), m_owner(owner), m_header_addr(header_addr), |
| m_code_start_addr(0), m_code_end_addr(0), m_next_region(0) { |
| SetUpRegion(); |
| } |
| |
| AppleObjCTrampolineHandler::~AppleObjCTrampolineHandler() {} |
| |
| void AppleObjCTrampolineHandler::AppleObjCVTables::VTableRegion::SetUpRegion() { |
| // The header looks like: |
| // |
| // uint16_t headerSize |
| // uint16_t descSize |
| // uint32_t descCount |
| // void * next |
| // |
| // First read in the header: |
| |
| char memory_buffer[16]; |
| ProcessSP process_sp = m_owner->GetProcessSP(); |
| if (!process_sp) |
| return; |
| DataExtractor data(memory_buffer, sizeof(memory_buffer), |
| process_sp->GetByteOrder(), |
| process_sp->GetAddressByteSize()); |
| size_t actual_size = 8 + process_sp->GetAddressByteSize(); |
| Status error; |
| size_t bytes_read = |
| process_sp->ReadMemory(m_header_addr, memory_buffer, actual_size, error); |
| if (bytes_read != actual_size) { |
| m_valid = false; |
| return; |
| } |
| |
| lldb::offset_t offset = 0; |
| const uint16_t header_size = data.GetU16(&offset); |
| const uint16_t descriptor_size = data.GetU16(&offset); |
| const size_t num_descriptors = data.GetU32(&offset); |
| |
| m_next_region = data.GetAddress(&offset); |
| |
| // If the header size is 0, that means we've come in too early before this |
| // data is set up. |
| // Set ourselves as not valid, and continue. |
| if (header_size == 0 || num_descriptors == 0) { |
| m_valid = false; |
| return; |
| } |
| |
| // Now read in all the descriptors: |
| // The descriptor looks like: |
| // |
| // uint32_t offset |
| // uint32_t flags |
| // |
| // Where offset is either 0 - in which case it is unused, or it is |
| // the offset of the vtable code from the beginning of the |
| // descriptor record. Below, we'll convert that into an absolute |
| // code address, since I don't want to have to compute it over and |
| // over. |
| |
| // Ingest the whole descriptor array: |
| const lldb::addr_t desc_ptr = m_header_addr + header_size; |
| const size_t desc_array_size = num_descriptors * descriptor_size; |
| DataBufferSP data_sp(new DataBufferHeap(desc_array_size, '\0')); |
| uint8_t *dst = (uint8_t *)data_sp->GetBytes(); |
| |
| DataExtractor desc_extractor(dst, desc_array_size, process_sp->GetByteOrder(), |
| process_sp->GetAddressByteSize()); |
| bytes_read = process_sp->ReadMemory(desc_ptr, dst, desc_array_size, error); |
| if (bytes_read != desc_array_size) { |
| m_valid = false; |
| return; |
| } |
| |
| // The actual code for the vtables will be laid out consecutively, so I also |
| // compute the start and end of the whole code block. |
| |
| offset = 0; |
| m_code_start_addr = 0; |
| m_code_end_addr = 0; |
| |
| for (size_t i = 0; i < num_descriptors; i++) { |
| lldb::addr_t start_offset = offset; |
| uint32_t voffset = desc_extractor.GetU32(&offset); |
| uint32_t flags = desc_extractor.GetU32(&offset); |
| lldb::addr_t code_addr = desc_ptr + start_offset + voffset; |
| m_descriptors.push_back(VTableDescriptor(flags, code_addr)); |
| |
| if (m_code_start_addr == 0 || code_addr < m_code_start_addr) |
| m_code_start_addr = code_addr; |
| if (code_addr > m_code_end_addr) |
| m_code_end_addr = code_addr; |
| |
| offset = start_offset + descriptor_size; |
| } |
| // Finally, a little bird told me that all the vtable code blocks |
| // are the same size. Let's compute the blocks and if they are all |
| // the same add the size to the code end address: |
| lldb::addr_t code_size = 0; |
| bool all_the_same = true; |
| for (size_t i = 0; i < num_descriptors - 1; i++) { |
| lldb::addr_t this_size = |
| m_descriptors[i + 1].code_start - m_descriptors[i].code_start; |
| if (code_size == 0) |
| code_size = this_size; |
| else { |
| if (this_size != code_size) |
| all_the_same = false; |
| if (this_size > code_size) |
| code_size = this_size; |
| } |
| } |
| if (all_the_same) |
| m_code_end_addr += code_size; |
| } |
| |
| bool AppleObjCTrampolineHandler::AppleObjCVTables::VTableRegion:: |
| AddressInRegion(lldb::addr_t addr, uint32_t &flags) { |
| if (!IsValid()) |
| return false; |
| |
| if (addr < m_code_start_addr || addr > m_code_end_addr) |
| return false; |
| |
| std::vector<VTableDescriptor>::iterator pos, end = m_descriptors.end(); |
| for (pos = m_descriptors.begin(); pos != end; pos++) { |
| if (addr <= (*pos).code_start) { |
| flags = (*pos).flags; |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| void AppleObjCTrampolineHandler::AppleObjCVTables::VTableRegion::Dump( |
| Stream &s) { |
| s.Printf("Header addr: 0x%" PRIx64 " Code start: 0x%" PRIx64 |
| " Code End: 0x%" PRIx64 " Next: 0x%" PRIx64 "\n", |
| m_header_addr, m_code_start_addr, m_code_end_addr, m_next_region); |
| size_t num_elements = m_descriptors.size(); |
| for (size_t i = 0; i < num_elements; i++) { |
| s.Indent(); |
| s.Printf("Code start: 0x%" PRIx64 " Flags: %d\n", |
| m_descriptors[i].code_start, m_descriptors[i].flags); |
| } |
| } |
| |
| AppleObjCTrampolineHandler::AppleObjCVTables::AppleObjCVTables( |
| const ProcessSP &process_sp, const ModuleSP &objc_module_sp) |
| : m_process_wp(), m_trampoline_header(LLDB_INVALID_ADDRESS), |
| m_trampolines_changed_bp_id(LLDB_INVALID_BREAK_ID), |
| m_objc_module_sp(objc_module_sp) { |
| if (process_sp) |
| m_process_wp = process_sp; |
| } |
| |
| AppleObjCTrampolineHandler::AppleObjCVTables::~AppleObjCVTables() { |
| ProcessSP process_sp = GetProcessSP(); |
| if (process_sp) { |
| if (m_trampolines_changed_bp_id != LLDB_INVALID_BREAK_ID) |
| process_sp->GetTarget().RemoveBreakpointByID(m_trampolines_changed_bp_id); |
| } |
| } |
| |
| bool AppleObjCTrampolineHandler::AppleObjCVTables::InitializeVTableSymbols() { |
| if (m_trampoline_header != LLDB_INVALID_ADDRESS) |
| return true; |
| |
| ProcessSP process_sp = GetProcessSP(); |
| if (process_sp) { |
| Target &target = process_sp->GetTarget(); |
| |
| if (!m_objc_module_sp) { |
| for (ModuleSP module_sp : target.GetImages().Modules()) { |
| if (ObjCLanguageRuntime::Get(*process_sp) |
| ->IsModuleObjCLibrary(module_sp)) { |
| m_objc_module_sp = module_sp; |
| break; |
| } |
| } |
| } |
| |
| if (m_objc_module_sp) { |
| ConstString trampoline_name("gdb_objc_trampolines"); |
| const Symbol *trampoline_symbol = |
| m_objc_module_sp->FindFirstSymbolWithNameAndType(trampoline_name, |
| eSymbolTypeData); |
| if (trampoline_symbol != nullptr) { |
| m_trampoline_header = trampoline_symbol->GetLoadAddress(&target); |
| if (m_trampoline_header == LLDB_INVALID_ADDRESS) |
| return false; |
| |
| // Next look up the "changed" symbol and set a breakpoint on that... |
| ConstString changed_name("gdb_objc_trampolines_changed"); |
| const Symbol *changed_symbol = |
| m_objc_module_sp->FindFirstSymbolWithNameAndType(changed_name, |
| eSymbolTypeCode); |
| if (changed_symbol != nullptr) { |
| const Address changed_symbol_addr = changed_symbol->GetAddress(); |
| if (!changed_symbol_addr.IsValid()) |
| return false; |
| |
| lldb::addr_t changed_addr = |
| changed_symbol_addr.GetOpcodeLoadAddress(&target); |
| if (changed_addr != LLDB_INVALID_ADDRESS) { |
| BreakpointSP trampolines_changed_bp_sp = |
| target.CreateBreakpoint(changed_addr, true, false); |
| if (trampolines_changed_bp_sp) { |
| m_trampolines_changed_bp_id = trampolines_changed_bp_sp->GetID(); |
| trampolines_changed_bp_sp->SetCallback(RefreshTrampolines, this, |
| true); |
| trampolines_changed_bp_sp->SetBreakpointKind( |
| "objc-trampolines-changed"); |
| return true; |
| } |
| } |
| } |
| } |
| } |
| } |
| return false; |
| } |
| |
| bool AppleObjCTrampolineHandler::AppleObjCVTables::RefreshTrampolines( |
| void *baton, StoppointCallbackContext *context, lldb::user_id_t break_id, |
| lldb::user_id_t break_loc_id) { |
| AppleObjCVTables *vtable_handler = (AppleObjCVTables *)baton; |
| if (vtable_handler->InitializeVTableSymbols()) { |
| // The Update function is called with the address of an added region. So we |
| // grab that address, and |
| // feed it into ReadRegions. Of course, our friend the ABI will get the |
| // values for us. |
| ExecutionContext exe_ctx(context->exe_ctx_ref); |
| Process *process = exe_ctx.GetProcessPtr(); |
| const ABI *abi = process->GetABI().get(); |
| |
| TypeSystemClang *clang_ast_context = |
| ScratchTypeSystemClang::GetForTarget(process->GetTarget()); |
| if (!clang_ast_context) |
| return false; |
| |
| ValueList argument_values; |
| Value input_value; |
| CompilerType clang_void_ptr_type = |
| clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); |
| |
| input_value.SetValueType(Value::eValueTypeScalar); |
| // input_value.SetContext (Value::eContextTypeClangType, |
| // clang_void_ptr_type); |
| input_value.SetCompilerType(clang_void_ptr_type); |
| argument_values.PushValue(input_value); |
| |
| bool success = |
| abi->GetArgumentValues(exe_ctx.GetThreadRef(), argument_values); |
| if (!success) |
| return false; |
| |
| // Now get a pointer value from the zeroth argument. |
| Status error; |
| DataExtractor data; |
| error = argument_values.GetValueAtIndex(0)->GetValueAsData(&exe_ctx, data, |
| nullptr); |
| lldb::offset_t offset = 0; |
| lldb::addr_t region_addr = data.GetAddress(&offset); |
| |
| if (region_addr != 0) |
| vtable_handler->ReadRegions(region_addr); |
| } |
| return false; |
| } |
| |
| bool AppleObjCTrampolineHandler::AppleObjCVTables::ReadRegions() { |
| // The no argument version reads the start region from the value of |
| // the gdb_regions_header, and gets started from there. |
| |
| m_regions.clear(); |
| if (!InitializeVTableSymbols()) |
| return false; |
| Status error; |
| ProcessSP process_sp = GetProcessSP(); |
| if (process_sp) { |
| lldb::addr_t region_addr = |
| process_sp->ReadPointerFromMemory(m_trampoline_header, error); |
| if (error.Success()) |
| return ReadRegions(region_addr); |
| } |
| return false; |
| } |
| |
| bool AppleObjCTrampolineHandler::AppleObjCVTables::ReadRegions( |
| lldb::addr_t region_addr) { |
| ProcessSP process_sp = GetProcessSP(); |
| if (!process_sp) |
| return false; |
| |
| Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); |
| |
| // We aren't starting at the trampoline symbol. |
| InitializeVTableSymbols(); |
| lldb::addr_t next_region = region_addr; |
| |
| // Read in the sizes of the headers. |
| while (next_region != 0) { |
| m_regions.push_back(VTableRegion(this, next_region)); |
| if (!m_regions.back().IsValid()) { |
| m_regions.clear(); |
| return false; |
| } |
| if (log) { |
| StreamString s; |
| m_regions.back().Dump(s); |
| LLDB_LOGF(log, "Read vtable region: \n%s", s.GetData()); |
| } |
| |
| next_region = m_regions.back().GetNextRegionAddr(); |
| } |
| |
| return true; |
| } |
| |
| bool AppleObjCTrampolineHandler::AppleObjCVTables::IsAddressInVTables( |
| lldb::addr_t addr, uint32_t &flags) { |
| region_collection::iterator pos, end = m_regions.end(); |
| for (pos = m_regions.begin(); pos != end; pos++) { |
| if ((*pos).AddressInRegion(addr, flags)) |
| return true; |
| } |
| return false; |
| } |
| |
| const AppleObjCTrampolineHandler::DispatchFunction |
| AppleObjCTrampolineHandler::g_dispatch_functions[] = { |
| // NAME STRET SUPER SUPER2 FIXUP TYPE |
| {"objc_msgSend", false, false, false, DispatchFunction::eFixUpNone}, |
| {"objc_msgSend_fixup", false, false, false, |
| DispatchFunction::eFixUpToFix}, |
| {"objc_msgSend_fixedup", false, false, false, |
| DispatchFunction::eFixUpFixed}, |
| {"objc_msgSend_stret", true, false, false, |
| DispatchFunction::eFixUpNone}, |
| {"objc_msgSend_stret_fixup", true, false, false, |
| DispatchFunction::eFixUpToFix}, |
| {"objc_msgSend_stret_fixedup", true, false, false, |
| DispatchFunction::eFixUpFixed}, |
| {"objc_msgSend_fpret", false, false, false, |
| DispatchFunction::eFixUpNone}, |
| {"objc_msgSend_fpret_fixup", false, false, false, |
| DispatchFunction::eFixUpToFix}, |
| {"objc_msgSend_fpret_fixedup", false, false, false, |
| DispatchFunction::eFixUpFixed}, |
| {"objc_msgSend_fp2ret", false, false, true, |
| DispatchFunction::eFixUpNone}, |
| {"objc_msgSend_fp2ret_fixup", false, false, true, |
| DispatchFunction::eFixUpToFix}, |
| {"objc_msgSend_fp2ret_fixedup", false, false, true, |
| DispatchFunction::eFixUpFixed}, |
| {"objc_msgSendSuper", false, true, false, DispatchFunction::eFixUpNone}, |
| {"objc_msgSendSuper_stret", true, true, false, |
| DispatchFunction::eFixUpNone}, |
| {"objc_msgSendSuper2", false, true, true, DispatchFunction::eFixUpNone}, |
| {"objc_msgSendSuper2_fixup", false, true, true, |
| DispatchFunction::eFixUpToFix}, |
| {"objc_msgSendSuper2_fixedup", false, true, true, |
| DispatchFunction::eFixUpFixed}, |
| {"objc_msgSendSuper2_stret", true, true, true, |
| DispatchFunction::eFixUpNone}, |
| {"objc_msgSendSuper2_stret_fixup", true, true, true, |
| DispatchFunction::eFixUpToFix}, |
| {"objc_msgSendSuper2_stret_fixedup", true, true, true, |
| DispatchFunction::eFixUpFixed}, |
| }; |
| |
| // This is the table of ObjC "accelerated dispatch" functions. They are a set |
| // of objc methods that are "seldom overridden" and so the compiler replaces the |
| // objc_msgSend with a call to one of the dispatch functions. That will check |
| // whether the method has been overridden, and directly call the Foundation |
| // implementation if not. |
| // This table is supposed to be complete. If ones get added in the future, we |
| // will have to add them to the table. |
| const char *AppleObjCTrampolineHandler::g_opt_dispatch_names[] = { |
| "objc_alloc", |
| "objc_autorelease", |
| "objc_release", |
| "objc_retain", |
| "objc_alloc_init", |
| "objc_allocWithZone", |
| "objc_opt_class", |
| "objc_opt_isKindOfClass", |
| "objc_opt_new", |
| "objc_opt_respondsToSelector", |
| "objc_opt_self", |
| }; |
| |
| AppleObjCTrampolineHandler::AppleObjCTrampolineHandler( |
| const ProcessSP &process_sp, const ModuleSP &objc_module_sp) |
| : m_process_wp(), m_objc_module_sp(objc_module_sp), |
| m_lookup_implementation_function_code(nullptr), |
| m_impl_fn_addr(LLDB_INVALID_ADDRESS), |
| m_impl_stret_fn_addr(LLDB_INVALID_ADDRESS), |
| m_msg_forward_addr(LLDB_INVALID_ADDRESS) { |
| if (process_sp) |
| m_process_wp = process_sp; |
| // Look up the known resolution functions: |
| |
| ConstString get_impl_name("class_getMethodImplementation"); |
| ConstString get_impl_stret_name("class_getMethodImplementation_stret"); |
| ConstString msg_forward_name("_objc_msgForward"); |
| ConstString msg_forward_stret_name("_objc_msgForward_stret"); |
| |
| Target *target = process_sp ? &process_sp->GetTarget() : nullptr; |
| 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); |
| const Symbol *msg_forward = m_objc_module_sp->FindFirstSymbolWithNameAndType( |
| msg_forward_name, eSymbolTypeCode); |
| const Symbol *msg_forward_stret = |
| m_objc_module_sp->FindFirstSymbolWithNameAndType(msg_forward_stret_name, |
| eSymbolTypeCode); |
| |
| if (class_getMethodImplementation) |
| m_impl_fn_addr = |
| class_getMethodImplementation->GetAddress().GetOpcodeLoadAddress( |
| target); |
| if (class_getMethodImplementation_stret) |
| m_impl_stret_fn_addr = |
| class_getMethodImplementation_stret->GetAddress().GetOpcodeLoadAddress( |
| target); |
| if (msg_forward) |
| m_msg_forward_addr = msg_forward->GetAddress().GetOpcodeLoadAddress(target); |
| if (msg_forward_stret) |
| m_msg_forward_stret_addr = |
| msg_forward_stret->GetAddress().GetOpcodeLoadAddress(target); |
| |
| // FIXME: Do some kind of logging here. |
| if (m_impl_fn_addr == LLDB_INVALID_ADDRESS) { |
| // If we can't even find the ordinary get method implementation function, |
| // then we aren't going to be able to |
| // step through any method dispatches. Warn to that effect and get out of |
| // here. |
| if (process_sp->CanJIT()) { |
| process_sp->GetTarget().GetDebugger().GetErrorStream().Printf( |
| "Could not find implementation lookup function \"%s\"" |
| " step in through ObjC method dispatch will not work.\n", |
| get_impl_name.AsCString()); |
| } |
| return; |
| } else if (m_impl_stret_fn_addr == LLDB_INVALID_ADDRESS) { |
| // It there is no stret return lookup function, assume that it is the same |
| // as the straight lookup: |
| m_impl_stret_fn_addr = m_impl_fn_addr; |
| // Also we will use the version of the lookup code that doesn't rely on the |
| // stret version of the function. |
| m_lookup_implementation_function_code = |
| g_lookup_implementation_no_stret_function_code; |
| } else { |
| m_lookup_implementation_function_code = |
| g_lookup_implementation_with_stret_function_code; |
| } |
| |
| // 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 (size_t i = 0; i != llvm::array_lengthof(g_dispatch_functions); 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 && msgSend_symbol->ValueIsAddress()) { |
| // FIXME: Make g_dispatch_functions static table of |
| // DispatchFunctions, 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->GetAddressRef().GetOpcodeLoadAddress(target); |
| |
| m_msgSend_map.insert(std::pair<lldb::addr_t, int>(sym_addr, i)); |
| } |
| } |
| |
| // Similarly, cache the addresses of the "optimized dispatch" function. |
| for (size_t i = 0; i != llvm::array_lengthof(g_opt_dispatch_names); i++) { |
| ConstString name_const_str(g_opt_dispatch_names[i]); |
| const Symbol *msgSend_symbol = |
| m_objc_module_sp->FindFirstSymbolWithNameAndType(name_const_str, |
| eSymbolTypeCode); |
| if (msgSend_symbol && msgSend_symbol->ValueIsAddress()) { |
| lldb::addr_t sym_addr = |
| msgSend_symbol->GetAddressRef().GetOpcodeLoadAddress(target); |
| |
| m_opt_dispatch_map.emplace(sym_addr, i); |
| } |
| } |
| |
| // Build our vtable dispatch handler here: |
| m_vtables_up = |
| std::make_unique<AppleObjCVTables>(process_sp, m_objc_module_sp); |
| if (m_vtables_up) |
| m_vtables_up->ReadRegions(); |
| } |
| |
| lldb::addr_t |
| AppleObjCTrampolineHandler::SetupDispatchFunction(Thread &thread, |
| ValueList &dispatch_values) { |
| ThreadSP thread_sp(thread.shared_from_this()); |
| ExecutionContext exe_ctx(thread_sp); |
| Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); |
| |
| lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; |
| FunctionCaller *impl_function_caller = nullptr; |
| |
| // Scope for mutex locker: |
| { |
| std::lock_guard<std::mutex> guard(m_impl_function_mutex); |
| |
| // First stage is to make the ClangUtility to hold our injected function: |
| |
| if (!m_impl_code) { |
| if (m_lookup_implementation_function_code != nullptr) { |
| auto utility_fn_or_error = exe_ctx.GetTargetRef().CreateUtilityFunction( |
| m_lookup_implementation_function_code, |
| g_lookup_implementation_function_name, eLanguageTypeC, exe_ctx); |
| if (!utility_fn_or_error) { |
| LLDB_LOG_ERROR( |
| log, utility_fn_or_error.takeError(), |
| "Failed to get Utility Function for implementation lookup: {0}."); |
| return args_addr; |
| } |
| m_impl_code = std::move(*utility_fn_or_error); |
| } else { |
| LLDB_LOGF(log, "No method lookup implementation code."); |
| return LLDB_INVALID_ADDRESS; |
| } |
| |
| // Next make the runner function for our implementation utility function. |
| TypeSystemClang *clang_ast_context = ScratchTypeSystemClang::GetForTarget( |
| thread.GetProcess()->GetTarget()); |
| if (!clang_ast_context) |
| return LLDB_INVALID_ADDRESS; |
| |
| CompilerType clang_void_ptr_type = |
| clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); |
| Status error; |
| |
| impl_function_caller = m_impl_code->MakeFunctionCaller( |
| clang_void_ptr_type, dispatch_values, thread_sp, error); |
| if (error.Fail()) { |
| LLDB_LOGF(log, |
| "Error getting function caller for dispatch lookup: \"%s\".", |
| error.AsCString()); |
| return args_addr; |
| } |
| } else { |
| impl_function_caller = m_impl_code->GetFunctionCaller(); |
| } |
| } |
| |
| // Now write down the argument values for this particular call. |
| // This looks like it might be a race condition if other threads |
| // were calling into here, but actually it isn't because we allocate |
| // a new args structure for this call by passing args_addr = |
| // LLDB_INVALID_ADDRESS... |
| |
| DiagnosticManager diagnostics; |
| if (!impl_function_caller->WriteFunctionArguments( |
| exe_ctx, args_addr, dispatch_values, diagnostics)) { |
| if (log) { |
| LLDB_LOGF(log, "Error writing function arguments."); |
| diagnostics.Dump(log); |
| } |
| return args_addr; |
| } |
| |
| return args_addr; |
| } |
| |
| const AppleObjCTrampolineHandler::DispatchFunction * |
| AppleObjCTrampolineHandler::FindDispatchFunction(lldb::addr_t addr) { |
| MsgsendMap::iterator pos; |
| pos = m_msgSend_map.find(addr); |
| if (pos != m_msgSend_map.end()) { |
| return &g_dispatch_functions[(*pos).second]; |
| } |
| return nullptr; |
| } |
| |
| void |
| AppleObjCTrampolineHandler::ForEachDispatchFunction( |
| std::function<void(lldb::addr_t, |
| const DispatchFunction &)> callback) { |
| for (auto elem : m_msgSend_map) { |
| callback(elem.first, g_dispatch_functions[elem.second]); |
| } |
| } |
| |
| ThreadPlanSP |
| AppleObjCTrampolineHandler::GetStepThroughDispatchPlan(Thread &thread, |
| bool stop_others) { |
| ThreadPlanSP ret_plan_sp; |
| lldb::addr_t curr_pc = thread.GetRegisterContext()->GetPC(); |
| |
| DispatchFunction vtable_dispatch |
| = {"vtable", 0, false, false, DispatchFunction::eFixUpFixed}; |
| |
| // First step is to look and see if we are in one of the known ObjC |
| // dispatch functions. We've already compiled a table of same, so |
| // consult it. |
| |
| const DispatchFunction *this_dispatch = FindDispatchFunction(curr_pc); |
| |
| // Next check to see if we are in a vtable region: |
| |
| if (!this_dispatch && m_vtables_up) { |
| uint32_t flags; |
| if (m_vtables_up->IsAddressInVTables(curr_pc, flags)) { |
| vtable_dispatch.stret_return = |
| (flags & AppleObjCVTables::eOBJC_TRAMPOLINE_STRET) == |
| AppleObjCVTables::eOBJC_TRAMPOLINE_STRET; |
| this_dispatch = &vtable_dispatch; |
| } |
| } |
| |
| if (this_dispatch) { |
| Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); |
| |
| // We are decoding a method dispatch. First job is to pull the |
| // arguments out: |
| |
| lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); |
| |
| const ABI *abi = nullptr; |
| ProcessSP process_sp(thread.CalculateProcess()); |
| if (process_sp) |
| abi = process_sp->GetABI().get(); |
| if (abi == nullptr) |
| return ret_plan_sp; |
| |
| TargetSP target_sp(thread.CalculateTarget()); |
| |
| TypeSystemClang *clang_ast_context = |
| ScratchTypeSystemClang::GetForTarget(*target_sp); |
| if (!clang_ast_context) |
| return ret_plan_sp; |
| |
| ValueList argument_values; |
| Value void_ptr_value; |
| CompilerType clang_void_ptr_type = |
| clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); |
| void_ptr_value.SetValueType(Value::eValueTypeScalar); |
| // void_ptr_value.SetContext (Value::eContextTypeClangType, |
| // clang_void_ptr_type); |
| void_ptr_value.SetCompilerType(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(void_ptr_value); |
| argument_values.PushValue(void_ptr_value); |
| argument_values.PushValue(void_ptr_value); |
| } else { |
| obj_index = 0; |
| sel_index = 1; |
| argument_values.PushValue(void_ptr_value); |
| argument_values.PushValue(void_ptr_value); |
| } |
| |
| bool success = abi->GetArgumentValues(thread, argument_values); |
| if (!success) |
| return ret_plan_sp; |
| |
| lldb::addr_t obj_addr = |
| argument_values.GetValueAtIndex(obj_index)->GetScalar().ULongLong(); |
| if (obj_addr == 0x0) { |
| LLDB_LOGF( |
| log, |
| "Asked to step to dispatch to nil object, returning empty plan."); |
| return ret_plan_sp; |
| } |
| |
| ExecutionContext exe_ctx(thread.shared_from_this()); |
| Process *process = exe_ctx.GetProcessPtr(); |
| // isa_addr will store the class pointer that the method is being |
| // dispatched to - so either the class directly or the super class |
| // if this is one of the objc_msgSendSuper flavors. That's mostly |
| // used to look up the class/selector pair in our cache. |
| |
| lldb::addr_t isa_addr = LLDB_INVALID_ADDRESS; |
| lldb::addr_t sel_addr = |
| argument_values.GetValueAtIndex(sel_index)->GetScalar().ULongLong(); |
| |
| // Figure out the class this is being dispatched to and see if |
| // we've already cached this method call, If so we can push a |
| // run-to-address plan directly. Otherwise we have to figure out |
| // where the implementation lives. |
| |
| if (this_dispatch->is_super) { |
| if (this_dispatch->is_super2) { |
| // In the objc_msgSendSuper2 case, we don't get the object |
| // directly, we get a structure containing the object and the |
| // class to which the super message is being sent. So we need |
| // to dig the super out of the class and use that. |
| |
| Value super_value(*(argument_values.GetValueAtIndex(obj_index))); |
| super_value.GetScalar() += process->GetAddressByteSize(); |
| super_value.ResolveValue(&exe_ctx); |
| |
| if (super_value.GetScalar().IsValid()) { |
| |
| // isa_value now holds the class pointer. The second word of the |
| // class pointer is the super-class pointer: |
| super_value.GetScalar() += process->GetAddressByteSize(); |
| super_value.ResolveValue(&exe_ctx); |
| if (super_value.GetScalar().IsValid()) |
| isa_addr = super_value.GetScalar().ULongLong(); |
| else { |
| LLDB_LOGF(log, "Failed to extract the super class value from the " |
| "class in objc_super."); |
| } |
| } else { |
| LLDB_LOGF(log, "Failed to extract the class value from objc_super."); |
| } |
| } else { |
| // In the objc_msgSendSuper case, we don't get the object |
| // directly, we get a two element structure containing the |
| // object and the super class to which the super message is |
| // being sent. So the class we want is the second element of |
| // this structure. |
| |
| Value super_value(*(argument_values.GetValueAtIndex(obj_index))); |
| super_value.GetScalar() += process->GetAddressByteSize(); |
| super_value.ResolveValue(&exe_ctx); |
| |
| if (super_value.GetScalar().IsValid()) { |
| isa_addr = super_value.GetScalar().ULongLong(); |
| } else { |
| LLDB_LOGF(log, "Failed to extract the class value from objc_super."); |
| } |
| } |
| } else { |
| // In the direct dispatch case, the object->isa is the class pointer we |
| // want. |
| |
| // 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... |
| |
| // Note, it isn't a fatal error not to be able to get the |
| // address from the object, since this might be a "tagged |
| // pointer" which isn't a real object, but rather some word |
| // length encoded dingus. |
| |
| Value isa_value(*(argument_values.GetValueAtIndex(obj_index))); |
| |
| isa_value.SetValueType(Value::eValueTypeLoadAddress); |
| isa_value.ResolveValue(&exe_ctx); |
| if (isa_value.GetScalar().IsValid()) { |
| isa_addr = isa_value.GetScalar().ULongLong(); |
| } else { |
| LLDB_LOGF(log, "Failed to extract the isa value from object."); |
| } |
| } |
| |
| // Okay, we've got the address of the class for which we're resolving this, |
| // let's see if it's in our cache: |
| lldb::addr_t impl_addr = LLDB_INVALID_ADDRESS; |
| |
| if (isa_addr != LLDB_INVALID_ADDRESS) { |
| if (log) { |
| LLDB_LOGF(log, |
| "Resolving call for class - 0x%" PRIx64 |
| " and selector - 0x%" PRIx64, |
| isa_addr, sel_addr); |
| } |
| ObjCLanguageRuntime *objc_runtime = |
| ObjCLanguageRuntime::Get(*thread.GetProcess()); |
| assert(objc_runtime != nullptr); |
| |
| impl_addr = objc_runtime->LookupInMethodCache(isa_addr, sel_addr); |
| } |
| |
| if (impl_addr != LLDB_INVALID_ADDRESS) { |
| // Yup, it was in the cache, so we can run to that address directly. |
| |
| LLDB_LOGF(log, "Found implementation address in cache: 0x%" PRIx64, |
| impl_addr); |
| |
| ret_plan_sp = std::make_shared<ThreadPlanRunToAddress>(thread, impl_addr, |
| stop_others); |
| } else { |
| // We haven't seen this class/selector pair yet. Look it up. |
| StreamString errors; |
| Address impl_code_address; |
| |
| ValueList dispatch_values; |
| |
| // We've will inject a little function in the target that takes the |
| // object, selector and some flags, |
| // and figures out the implementation. Looks like: |
| // void *__lldb_objc_find_implementation_for_selector (void *object, |
| // void *sel, |
| // int is_stret, |
| // int is_super, |
| // int is_super2, |
| // int is_fixup, |
| // int is_fixed, |
| // int debug) |
| // So set up the arguments for that call. |
| |
| dispatch_values.PushValue(*(argument_values.GetValueAtIndex(obj_index))); |
| dispatch_values.PushValue(*(argument_values.GetValueAtIndex(sel_index))); |
| |
| Value flag_value; |
| CompilerType clang_int_type = |
| clang_ast_context->GetBuiltinTypeForEncodingAndBitSize( |
| lldb::eEncodingSint, 32); |
| flag_value.SetValueType(Value::eValueTypeScalar); |
| // flag_value.SetContext (Value::eContextTypeClangType, clang_int_type); |
| flag_value.SetCompilerType(clang_int_type); |
| |
| if (this_dispatch->stret_return) |
| flag_value.GetScalar() = 1; |
| else |
| flag_value.GetScalar() = 0; |
| dispatch_values.PushValue(flag_value); |
| |
| if (this_dispatch->is_super) |
| flag_value.GetScalar() = 1; |
| else |
| flag_value.GetScalar() = 0; |
| dispatch_values.PushValue(flag_value); |
| |
| if (this_dispatch->is_super2) |
| flag_value.GetScalar() = 1; |
| else |
| flag_value.GetScalar() = 0; |
| dispatch_values.PushValue(flag_value); |
| |
| switch (this_dispatch->fixedup) { |
| case DispatchFunction::eFixUpNone: |
| flag_value.GetScalar() = 0; |
| dispatch_values.PushValue(flag_value); |
| dispatch_values.PushValue(flag_value); |
| break; |
| case DispatchFunction::eFixUpFixed: |
| flag_value.GetScalar() = 1; |
| dispatch_values.PushValue(flag_value); |
| flag_value.GetScalar() = 1; |
| dispatch_values.PushValue(flag_value); |
| break; |
| case DispatchFunction::eFixUpToFix: |
| flag_value.GetScalar() = 1; |
| dispatch_values.PushValue(flag_value); |
| flag_value.GetScalar() = 0; |
| dispatch_values.PushValue(flag_value); |
| break; |
| } |
| if (log && log->GetVerbose()) |
| flag_value.GetScalar() = 1; |
| else |
| flag_value.GetScalar() = 0; // FIXME - Set to 0 when debugging is done. |
| dispatch_values.PushValue(flag_value); |
| |
| ret_plan_sp = std::make_shared<AppleThreadPlanStepThroughObjCTrampoline>( |
| thread, *this, dispatch_values, isa_addr, sel_addr); |
| if (log) { |
| StreamString s; |
| ret_plan_sp->GetDescription(&s, eDescriptionLevelFull); |
| LLDB_LOGF(log, "Using ObjC step plan: %s.\n", s.GetData()); |
| } |
| } |
| } |
| |
| // Finally, check if we have hit an "optimized dispatch" function. This will |
| // either directly call the base implementation or dispatch an objc_msgSend |
| // if the method has been overridden. So we just do a "step in/step out", |
| // setting a breakpoint on objc_msgSend, and if we hit the msgSend, we |
| // will automatically step in again. That's the job of the |
| // AppleThreadPlanStepThroughDirectDispatch. |
| if (!this_dispatch && !ret_plan_sp) { |
| MsgsendMap::iterator pos; |
| pos = m_opt_dispatch_map.find(curr_pc); |
| if (pos != m_opt_dispatch_map.end()) { |
| const char *opt_name = g_opt_dispatch_names[(*pos).second]; |
| ret_plan_sp = std::make_shared<AppleThreadPlanStepThroughDirectDispatch>( |
| thread, *this, opt_name); |
| } |
| } |
| |
| return ret_plan_sp; |
| } |
| |
| FunctionCaller * |
| AppleObjCTrampolineHandler::GetLookupImplementationFunctionCaller() { |
| return m_impl_code->GetFunctionCaller(); |
| } |
