| //===-- AppleObjCTrampolineHandler.cpp ----------------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "lldb/lldb-python.h" |
| |
| #include "AppleObjCTrampolineHandler.h" |
| |
| // C Includes |
| // C++ Includes |
| // Other libraries and framework includes |
| // Project includes |
| #include "AppleThreadPlanStepThroughObjCTrampoline.h" |
| |
| #include "lldb/Breakpoint/StoppointCallbackContext.h" |
| #include "lldb/Core/ConstString.h" |
| #include "lldb/Core/Debugger.h" |
| #include "lldb/Core/Log.h" |
| #include "lldb/Core/Module.h" |
| #include "lldb/Core/StreamFile.h" |
| #include "lldb/Core/Value.h" |
| #include "lldb/Expression/ClangExpression.h" |
| #include "lldb/Expression/ClangFunction.h" |
| #include "lldb/Expression/ClangUtilityFunction.h" |
| #include "lldb/Host/FileSpec.h" |
| #include "lldb/Symbol/ClangASTContext.h" |
| #include "lldb/Symbol/Symbol.h" |
| #include "lldb/Target/ObjCLanguageRuntime.h" |
| #include "lldb/Target/Process.h" |
| #include "lldb/Target/RegisterContext.h" |
| #include "lldb/Target/Target.h" |
| #include "lldb/Target/Thread.h" |
| #include "lldb/Target/ExecutionContext.h" |
| #include "lldb/Target/ThreadPlanRunToAddress.h" |
| |
| #include "llvm/ADT/STLExtras.h" |
| |
| 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_function_code = NULL; |
| 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, 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 *reciever; \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 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 = class_getMethodImplementation_stret (return_struct.class_addr, \n\ |
| return_struct.sel_addr); \n\ |
| } \n\ |
| else \n\ |
| { \n\ |
| return_struct.impl_addr = class_getMethodImplementation (return_struct.class_addr, \n\ |
| return_struct.sel_addr); \n\ |
| } \n\ |
| if (debug) \n\ |
| printf (\"\\n*** Returning implementation: %p.\\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 *reciever; \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 = class_getMethodImplementation (return_struct.class_addr, \n\ |
| return_struct.sel_addr); \n\ |
| if (debug) \n\ |
| printf (\"\\n*** Returning implementation: 0x%p.\\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]; |
| Process *process = m_owner->GetProcess(); |
| DataExtractor data(memory_buffer, sizeof(memory_buffer), |
| process->GetByteOrder(), |
| process->GetAddressByteSize()); |
| size_t actual_size = 8 + process->GetAddressByteSize(); |
| Error error; |
| size_t bytes_read = process->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.GetPointer(&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->GetByteOrder(), |
| process->GetAddressByteSize()); |
| bytes_read = process->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_sp (process_sp), |
| m_trampoline_header (LLDB_INVALID_ADDRESS), |
| m_trampolines_changed_bp_id (LLDB_INVALID_BREAK_ID), |
| m_objc_module_sp (objc_module_sp) |
| { |
| |
| } |
| |
| AppleObjCTrampolineHandler::AppleObjCVTables::~AppleObjCVTables() |
| { |
| if (m_trampolines_changed_bp_id != LLDB_INVALID_BREAK_ID) |
| m_process_sp->GetTarget().RemoveBreakpointByID (m_trampolines_changed_bp_id); |
| } |
| |
| bool |
| AppleObjCTrampolineHandler::AppleObjCVTables::InitializeVTableSymbols () |
| { |
| if (m_trampoline_header != LLDB_INVALID_ADDRESS) |
| return true; |
| Target &target = m_process_sp->GetTarget(); |
| |
| const ModuleList &target_modules = target.GetImages(); |
| Mutex::Locker modules_locker(target_modules.GetMutex()); |
| size_t num_modules = target_modules.GetSize(); |
| if (!m_objc_module_sp) |
| { |
| for (size_t i = 0; i < num_modules; i++) |
| { |
| if (m_process_sp->GetObjCLanguageRuntime()->IsModuleObjCLibrary (target_modules.GetModuleAtIndexUnlocked(i))) |
| { |
| m_objc_module_sp = target_modules.GetModuleAtIndexUnlocked(i); |
| 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 != NULL) |
| { |
| if (!trampoline_symbol->GetAddress().IsValid()) |
| return false; |
| |
| m_trampoline_header = trampoline_symbol->GetAddress().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 != NULL) |
| { |
| if (!changed_symbol->GetAddress().IsValid()) |
| return false; |
| |
| lldb::addr_t changed_addr = changed_symbol->GetAddress().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(); |
| |
| ClangASTContext *clang_ast_context = process->GetTarget().GetScratchClangASTContext(); |
| ValueList argument_values; |
| Value input_value; |
| ClangASTType 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.SetClangType (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. |
| Error error; |
| DataExtractor data; |
| error = argument_values.GetValueAtIndex(0)->GetValueAsData (&exe_ctx, |
| data, |
| 0, |
| NULL); |
| lldb::offset_t offset = 0; |
| lldb::addr_t region_addr = data.GetPointer(&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; |
| Error error; |
| lldb::addr_t region_addr = m_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) |
| { |
| if (!m_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); |
| log->Printf("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 }, |
| }; |
| |
| AppleObjCTrampolineHandler::AppleObjCTrampolineHandler (const ProcessSP &process_sp, |
| const ModuleSP &objc_module_sp) : |
| m_process_sp (process_sp), |
| m_objc_module_sp (objc_module_sp), |
| m_impl_fn_addr (LLDB_INVALID_ADDRESS), |
| m_impl_stret_fn_addr (LLDB_INVALID_ADDRESS), |
| m_msg_forward_addr (LLDB_INVALID_ADDRESS) |
| { |
| // 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 = m_process_sp ? &m_process_sp->GetTarget() : NULL; |
| 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().GetErrorFile()->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. |
| g_lookup_implementation_function_code = g_lookup_implementation_no_stret_function_code; |
| } |
| else |
| { |
| g_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) |
| { |
| // 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->GetAddress().GetOpcodeLoadAddress(target); |
| |
| m_msgSend_map.insert(std::pair<lldb::addr_t, int>(sym_addr, i)); |
| } |
| } |
| |
| // Build our vtable dispatch handler here: |
| m_vtables_ap.reset(new AppleObjCVTables(process_sp, m_objc_module_sp)); |
| if (m_vtables_ap.get()) |
| m_vtables_ap->ReadRegions(); |
| } |
| |
| lldb::addr_t |
| AppleObjCTrampolineHandler::SetupDispatchFunction (Thread &thread, ValueList &dispatch_values) |
| { |
| ExecutionContext exe_ctx (thread.shared_from_this()); |
| Address impl_code_address; |
| StreamString errors; |
| Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); |
| lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; |
| |
| // Scope for mutex locker: |
| { |
| Mutex::Locker locker(m_impl_function_mutex); |
| |
| // First stage is to make the ClangUtility to hold our injected function: |
| |
| #define USE_BUILTIN_FUNCTION 0 // Define this to 1 and we will use the get_implementation function found in the target. |
| // This is useful for debugging additions to the get_impl function 'cause you don't have |
| // to bother with string-ifying the code into g_lookup_implementation_function_code. |
| |
| if (USE_BUILTIN_FUNCTION) |
| { |
| ConstString our_utility_function_name("__lldb_objc_find_implementation_for_selector"); |
| SymbolContextList sc_list; |
| |
| exe_ctx.GetTargetRef().GetImages().FindSymbolsWithNameAndType (our_utility_function_name, eSymbolTypeCode, sc_list); |
| if (sc_list.GetSize() == 1) |
| { |
| SymbolContext sc; |
| sc_list.GetContextAtIndex(0, sc); |
| if (sc.symbol != NULL) |
| impl_code_address = sc.symbol->GetAddress(); |
| |
| //lldb::addr_t addr = impl_code_address.GetOpcodeLoadAddress (exe_ctx.GetTargetPtr()); |
| //printf ("Getting address for our_utility_function: 0x%" PRIx64 ".\n", addr); |
| } |
| else |
| { |
| //printf ("Could not find implementation function address.\n"); |
| return args_addr; |
| } |
| } |
| else if (!m_impl_code.get()) |
| { |
| if (g_lookup_implementation_function_code != NULL) |
| { |
| m_impl_code.reset (new ClangUtilityFunction (g_lookup_implementation_function_code, |
| g_lookup_implementation_function_name)); |
| if (!m_impl_code->Install(errors, exe_ctx)) |
| { |
| if (log) |
| log->Printf ("Failed to install implementation lookup: %s.", errors.GetData()); |
| m_impl_code.reset(); |
| return args_addr; |
| } |
| } |
| else |
| { |
| if (log) |
| log->Printf("No method lookup implementation code."); |
| errors.Printf ("No method lookup implementation code found."); |
| return LLDB_INVALID_ADDRESS; |
| } |
| |
| impl_code_address.Clear(); |
| impl_code_address.SetOffset(m_impl_code->StartAddress()); |
| } |
| else |
| { |
| impl_code_address.Clear(); |
| impl_code_address.SetOffset(m_impl_code->StartAddress()); |
| } |
| |
| // Next make the runner function for our implementation utility function. |
| if (!m_impl_function.get()) |
| { |
| ClangASTContext *clang_ast_context = thread.GetProcess()->GetTarget().GetScratchClangASTContext(); |
| ClangASTType clang_void_ptr_type = clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); |
| m_impl_function.reset(new ClangFunction (thread, |
| clang_void_ptr_type, |
| impl_code_address, |
| dispatch_values, |
| "objc-dispatch-lookup")); |
| |
| errors.Clear(); |
| unsigned num_errors = m_impl_function->CompileFunction(errors); |
| if (num_errors) |
| { |
| if (log) |
| log->Printf ("Error compiling function: \"%s\".", errors.GetData()); |
| return args_addr; |
| } |
| |
| errors.Clear(); |
| if (!m_impl_function->WriteFunctionWrapper(exe_ctx, errors)) |
| { |
| if (log) |
| log->Printf ("Error Inserting function: \"%s\".", errors.GetData()); |
| return args_addr; |
| } |
| } |
| } |
| |
| errors.Clear(); |
| |
| // 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... |
| |
| if (!m_impl_function->WriteFunctionArguments (exe_ctx, args_addr, impl_code_address, dispatch_values, errors)) |
| { |
| if (log) |
| log->Printf ("Error writing function arguments: \"%s\".", errors.GetData()); |
| return args_addr; |
| } |
| |
| return args_addr; |
| } |
| |
| ThreadPlanSP |
| AppleObjCTrampolineHandler::GetStepThroughDispatchPlan (Thread &thread, bool stop_others) |
| { |
| ThreadPlanSP ret_plan_sp; |
| lldb::addr_t curr_pc = thread.GetRegisterContext()->GetPC(); |
| |
| DispatchFunction this_dispatch; |
| bool found_it = false; |
| |
| // 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. |
| |
| MsgsendMap::iterator pos; |
| pos = m_msgSend_map.find (curr_pc); |
| if (pos != m_msgSend_map.end()) |
| { |
| this_dispatch = g_dispatch_functions[(*pos).second]; |
| found_it = true; |
| } |
| |
| // Next check to see if we are in a vtable region: |
| |
| if (!found_it) |
| { |
| uint32_t flags; |
| if (m_vtables_ap.get()) |
| { |
| found_it = m_vtables_ap->IsAddressInVTables (curr_pc, flags); |
| if (found_it) |
| { |
| this_dispatch.name = "vtable"; |
| this_dispatch.stret_return |
| = (flags & AppleObjCVTables::eOBJC_TRAMPOLINE_STRET) == AppleObjCVTables::eOBJC_TRAMPOLINE_STRET; |
| this_dispatch.is_super = false; |
| this_dispatch.is_super2 = false; |
| this_dispatch.fixedup = DispatchFunction::eFixUpFixed; |
| } |
| } |
| } |
| |
| if (found_it) |
| { |
| 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 = NULL; |
| ProcessSP process_sp (thread.CalculateProcess()); |
| if (process_sp) |
| abi = process_sp->GetABI().get(); |
| if (abi == NULL) |
| return ret_plan_sp; |
| |
| TargetSP target_sp (thread.CalculateTarget()); |
| |
| ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); |
| ValueList argument_values; |
| Value void_ptr_value; |
| ClangASTType 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.SetClangType (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) |
| { |
| if (log) |
| log->Printf("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 |
| { |
| if (log) |
| log->Printf("Failed to extract the super class value from the class in objc_super."); |
| } |
| } |
| else |
| { |
| if (log) |
| log->Printf("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 |
| { |
| if (log) |
| log->Printf("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 |
| { |
| if (log) |
| log->Printf("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) |
| { |
| log->Printf("Resolving call for class - 0x%" PRIx64 " and selector - 0x%" PRIx64, |
| isa_addr, sel_addr); |
| } |
| ObjCLanguageRuntime *objc_runtime = m_process_sp->GetObjCLanguageRuntime (); |
| assert(objc_runtime != NULL); |
| |
| 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. |
| |
| if (log) |
| log->Printf ("Found implementation address in cache: 0x%" PRIx64, impl_addr); |
| |
| ret_plan_sp.reset (new 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; |
| ClangASTType 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.SetClangType (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); |
| |
| |
| // The step through code might have to fill in the cache, so it is not safe to run only one thread. |
| // So we override the stop_others value passed in to us here: |
| const bool trampoline_stop_others = false; |
| ret_plan_sp.reset (new AppleThreadPlanStepThroughObjCTrampoline (thread, |
| this, |
| dispatch_values, |
| isa_addr, |
| sel_addr, |
| trampoline_stop_others)); |
| if (log) |
| { |
| StreamString s; |
| ret_plan_sp->GetDescription(&s, eDescriptionLevelFull); |
| log->Printf("Using ObjC step plan: %s.\n", s.GetData()); |
| } |
| } |
| } |
| |
| return ret_plan_sp; |
| } |
| |
| ClangFunction * |
| AppleObjCTrampolineHandler::GetLookupImplementationWrapperFunction () |
| { |
| return m_impl_function.get(); |
| } |
