AppleObjCTrampolineHandler.cpp revision 344779
1314564Sdim//===-- AppleObjCTrampolineHandler.cpp ----------------------------*- C++ 2314564Sdim//-*-===// 3293116Semaste// 4293116Semaste// The LLVM Compiler Infrastructure 5293116Semaste// 6293116Semaste// This file is distributed under the University of Illinois Open Source 7293116Semaste// License. See LICENSE.TXT for details. 8293116Semaste// 9293116Semaste//===----------------------------------------------------------------------===// 10293116Semaste 11293116Semaste#include "AppleObjCTrampolineHandler.h" 12293116Semaste 13293116Semaste#include "AppleThreadPlanStepThroughObjCTrampoline.h" 14293116Semaste 15293116Semaste#include "lldb/Breakpoint/StoppointCallbackContext.h" 16293116Semaste#include "lldb/Core/Debugger.h" 17293116Semaste#include "lldb/Core/Module.h" 18293116Semaste#include "lldb/Core/StreamFile.h" 19293116Semaste#include "lldb/Core/Value.h" 20309124Sdim#include "lldb/Expression/DiagnosticManager.h" 21309124Sdim#include "lldb/Expression/FunctionCaller.h" 22293116Semaste#include "lldb/Expression/UserExpression.h" 23293116Semaste#include "lldb/Expression/UtilityFunction.h" 24293116Semaste#include "lldb/Symbol/ClangASTContext.h" 25293116Semaste#include "lldb/Symbol/Symbol.h" 26293116Semaste#include "lldb/Target/ABI.h" 27309124Sdim#include "lldb/Target/ExecutionContext.h" 28293116Semaste#include "lldb/Target/ObjCLanguageRuntime.h" 29293116Semaste#include "lldb/Target/Process.h" 30293116Semaste#include "lldb/Target/RegisterContext.h" 31293116Semaste#include "lldb/Target/Target.h" 32293116Semaste#include "lldb/Target/Thread.h" 33293116Semaste#include "lldb/Target/ThreadPlanRunToAddress.h" 34321369Sdim#include "lldb/Utility/ConstString.h" 35321369Sdim#include "lldb/Utility/FileSpec.h" 36321369Sdim#include "lldb/Utility/Log.h" 37293116Semaste 38293116Semaste#include "llvm/ADT/STLExtras.h" 39293116Semaste 40293116Semasteusing namespace lldb; 41293116Semasteusing namespace lldb_private; 42293116Semaste 43314564Sdimconst char *AppleObjCTrampolineHandler::g_lookup_implementation_function_name = 44314564Sdim "__lldb_objc_find_implementation_for_selector"; 45314564Sdimconst char *AppleObjCTrampolineHandler:: 46314564Sdim g_lookup_implementation_with_stret_function_code = 47314564Sdim " \n\ 48341825Sdimextern \"C\" \n\ 49341825Sdim{ \n\ 50341825Sdim extern void *class_getMethodImplementation(void *objc_class, void *sel); \n\ 51341825Sdim extern void *class_getMethodImplementation_stret(void *objc_class, \n\ 52341825Sdim void *sel); \n\ 53341825Sdim extern void * object_getClass (id object); \n\ 54341825Sdim extern void * sel_getUid(char *name); \n\ 55341825Sdim extern int printf(const char *format, ...); \n\ 56341825Sdim} \n\ 57341825Sdimextern \"C\" void * __lldb_objc_find_implementation_for_selector ( \n\ 58341825Sdim void *object, \n\ 59341825Sdim void *sel, \n\ 60341825Sdim int is_stret, \n\ 61341825Sdim int is_super, \n\ 62341825Sdim int is_super2, \n\ 63341825Sdim int is_fixup, \n\ 64341825Sdim int is_fixed, \n\ 65341825Sdim int debug) \n\ 66341825Sdim{ \n\ 67341825Sdim struct __lldb_imp_return_struct \n\ 68341825Sdim { \n\ 69341825Sdim void *class_addr; \n\ 70341825Sdim void *sel_addr; \n\ 71341825Sdim void *impl_addr; \n\ 72341825Sdim }; \n\ 73341825Sdim \n\ 74341825Sdim struct __lldb_objc_class { \n\ 75341825Sdim void *isa; \n\ 76341825Sdim void *super_ptr; \n\ 77341825Sdim }; \n\ 78341825Sdim struct __lldb_objc_super { \n\ 79344779Sdim void *receiver; \n\ 80341825Sdim struct __lldb_objc_class *class_ptr; \n\ 81341825Sdim }; \n\ 82341825Sdim struct __lldb_msg_ref { \n\ 83341825Sdim void *dont_know; \n\ 84341825Sdim void *sel; \n\ 85341825Sdim }; \n\ 86341825Sdim \n\ 87341825Sdim struct __lldb_imp_return_struct return_struct; \n\ 88341825Sdim \n\ 89341825Sdim if (debug) \n\ 90341825Sdim printf (\"\\n*** Called with obj: 0x%p sel: 0x%p is_stret: %d is_super: %d, \"\n\ 91341825Sdim \"is_super2: %d, is_fixup: %d, is_fixed: %d\\n\", \n\ 92341825Sdim object, sel, is_stret, is_super, is_super2, is_fixup, is_fixed);\n\ 93341825Sdim if (is_super) \n\ 94341825Sdim { \n\ 95341825Sdim if (is_super2) \n\ 96341825Sdim { \n\ 97341825Sdim return_struct.class_addr = ((__lldb_objc_super *) object)->class_ptr->super_ptr;\n\ 98341825Sdim } \n\ 99341825Sdim else \n\ 100341825Sdim { \n\ 101341825Sdim return_struct.class_addr = ((__lldb_objc_super *) object)->class_ptr;\n\ 102341825Sdim } \n\ 103341825Sdim } \n\ 104341825Sdim else \n\ 105341825Sdim { \n\ 106341825Sdim // This code seems a little funny, but has its reasons... \n\ 107341825Sdim \n\ 108341825Sdim // The call to [object class] is here because if this is a \n\ 109341825Sdim // class, and has not been called into yet, we need to do \n\ 110341825Sdim // something to force the class to initialize itself. \n\ 111341825Sdim // Then the call to object_getClass will actually return the \n\ 112341825Sdim // correct class, either the class if object is a class \n\ 113341825Sdim // instance, or the meta-class if it is a class pointer. \n\ 114341825Sdim void *class_ptr = (void *) [(id) object class]; \n\ 115341825Sdim return_struct.class_addr = (id) object_getClass((id) object); \n\ 116341825Sdim if (debug) \n\ 117341825Sdim { \n\ 118341825Sdim if (class_ptr == object) \n\ 119341825Sdim { \n\ 120341825Sdim printf (\"Found a class object, need to use the meta class %p -> %p\\n\",\n\ 121341825Sdim class_ptr, return_struct.class_addr); \n\ 122341825Sdim } \n\ 123341825Sdim else \n\ 124341825Sdim { \n\ 125341825Sdim printf (\"[object class] returned: %p object_getClass: %p.\\n\", \n\ 126341825Sdim class_ptr, return_struct.class_addr); \n\ 127341825Sdim } \n\ 128341825Sdim } \n\ 129341825Sdim } \n\ 130341825Sdim \n\ 131341825Sdim if (is_fixup) \n\ 132341825Sdim { \n\ 133341825Sdim if (is_fixed) \n\ 134341825Sdim { \n\ 135341825Sdim return_struct.sel_addr = ((__lldb_msg_ref *) sel)->sel; \n\ 136341825Sdim } \n\ 137341825Sdim else \n\ 138341825Sdim { \n\ 139341825Sdim char *sel_name = (char *) ((__lldb_msg_ref *) sel)->sel; \n\ 140341825Sdim return_struct.sel_addr = sel_getUid (sel_name); \n\ 141341825Sdim if (debug) \n\ 142341825Sdim printf (\"\\n*** Got fixed up selector: %p for name %s.\\n\",\n\ 143341825Sdim return_struct.sel_addr, sel_name); \n\ 144341825Sdim } \n\ 145341825Sdim } \n\ 146341825Sdim else \n\ 147341825Sdim { \n\ 148341825Sdim return_struct.sel_addr = sel; \n\ 149341825Sdim } \n\ 150341825Sdim \n\ 151341825Sdim if (is_stret) \n\ 152341825Sdim { \n\ 153341825Sdim return_struct.impl_addr = \n\ 154341825Sdim class_getMethodImplementation_stret (return_struct.class_addr, \n\ 155341825Sdim return_struct.sel_addr); \n\ 156341825Sdim } \n\ 157341825Sdim else \n\ 158341825Sdim { \n\ 159341825Sdim return_struct.impl_addr = \n\ 160341825Sdim class_getMethodImplementation (return_struct.class_addr, \n\ 161341825Sdim return_struct.sel_addr); \n\ 162341825Sdim } \n\ 163341825Sdim if (debug) \n\ 164341825Sdim printf (\"\\n*** Returning implementation: %p.\\n\", \n\ 165341825Sdim return_struct.impl_addr); \n\ 166341825Sdim \n\ 167341825Sdim return return_struct.impl_addr; \n\ 168341825Sdim} \n\ 169293116Semaste"; 170314564Sdimconst char * 171314564Sdim AppleObjCTrampolineHandler::g_lookup_implementation_no_stret_function_code = 172314564Sdim " \n\ 173341825Sdimextern \"C\" \n\ 174341825Sdim{ \n\ 175341825Sdim extern void *class_getMethodImplementation(void *objc_class, void *sel); \n\ 176341825Sdim extern void * object_getClass (id object); \n\ 177341825Sdim extern void * sel_getUid(char *name); \n\ 178341825Sdim extern int printf(const char *format, ...); \n\ 179341825Sdim} \n\ 180293116Semasteextern \"C\" void * __lldb_objc_find_implementation_for_selector (void *object, \n\ 181341825Sdim void *sel, \n\ 182341825Sdim int is_stret, \n\ 183341825Sdim int is_super, \n\ 184341825Sdim int is_super2, \n\ 185341825Sdim int is_fixup, \n\ 186341825Sdim int is_fixed, \n\ 187341825Sdim int debug) \n\ 188341825Sdim{ \n\ 189341825Sdim struct __lldb_imp_return_struct \n\ 190341825Sdim { \n\ 191341825Sdim void *class_addr; \n\ 192341825Sdim void *sel_addr; \n\ 193341825Sdim void *impl_addr; \n\ 194341825Sdim }; \n\ 195341825Sdim \n\ 196341825Sdim struct __lldb_objc_class { \n\ 197341825Sdim void *isa; \n\ 198341825Sdim void *super_ptr; \n\ 199341825Sdim }; \n\ 200341825Sdim struct __lldb_objc_super { \n\ 201344779Sdim void *receiver; \n\ 202341825Sdim struct __lldb_objc_class *class_ptr; \n\ 203341825Sdim }; \n\ 204341825Sdim struct __lldb_msg_ref { \n\ 205341825Sdim void *dont_know; \n\ 206341825Sdim void *sel; \n\ 207341825Sdim }; \n\ 208341825Sdim \n\ 209341825Sdim struct __lldb_imp_return_struct return_struct; \n\ 210341825Sdim \n\ 211341825Sdim if (debug) \n\ 212293116Semaste printf (\"\\n*** Called with obj: 0x%p sel: 0x%p is_stret: %d is_super: %d, \" \n\ 213341825Sdim \"is_super2: %d, is_fixup: %d, is_fixed: %d\\n\", \n\ 214293116Semaste object, sel, is_stret, is_super, is_super2, is_fixup, is_fixed); \n\ 215341825Sdim if (is_super) \n\ 216341825Sdim { \n\ 217341825Sdim if (is_super2) \n\ 218341825Sdim { \n\ 219293116Semaste return_struct.class_addr = ((__lldb_objc_super *) object)->class_ptr->super_ptr; \n\ 220341825Sdim } \n\ 221341825Sdim else \n\ 222341825Sdim { \n\ 223293116Semaste return_struct.class_addr = ((__lldb_objc_super *) object)->class_ptr; \n\ 224341825Sdim } \n\ 225341825Sdim } \n\ 226341825Sdim else \n\ 227341825Sdim { \n\ 228341825Sdim // This code seems a little funny, but has its reasons... \n\ 229293116Semaste // The call to [object class] is here because if this is a class, and has not been called into \n\ 230293116Semaste // yet, we need to do something to force the class to initialize itself. \n\ 231293116Semaste // Then the call to object_getClass will actually return the correct class, either the class \n\ 232293116Semaste // if object is a class instance, or the meta-class if it is a class pointer. \n\ 233341825Sdim void *class_ptr = (void *) [(id) object class]; \n\ 234341825Sdim return_struct.class_addr = (id) object_getClass((id) object); \n\ 235341825Sdim if (debug) \n\ 236341825Sdim { \n\ 237341825Sdim if (class_ptr == object) \n\ 238341825Sdim { \n\ 239293116Semaste printf (\"Found a class object, need to return the meta class %p -> %p\\n\", \n\ 240341825Sdim class_ptr, return_struct.class_addr); \n\ 241341825Sdim } \n\ 242341825Sdim else \n\ 243341825Sdim { \n\ 244293116Semaste printf (\"[object class] returned: %p object_getClass: %p.\\n\", \n\ 245341825Sdim class_ptr, return_struct.class_addr); \n\ 246341825Sdim } \n\ 247341825Sdim } \n\ 248341825Sdim } \n\ 249341825Sdim \n\ 250341825Sdim if (is_fixup) \n\ 251341825Sdim { \n\ 252341825Sdim if (is_fixed) \n\ 253341825Sdim { \n\ 254341825Sdim return_struct.sel_addr = ((__lldb_msg_ref *) sel)->sel; \n\ 255341825Sdim } \n\ 256341825Sdim else \n\ 257341825Sdim { \n\ 258341825Sdim char *sel_name = (char *) ((__lldb_msg_ref *) sel)->sel; \n\ 259341825Sdim return_struct.sel_addr = sel_getUid (sel_name); \n\ 260341825Sdim if (debug) \n\ 261341825Sdim printf (\"\\n*** Got fixed up selector: %p for name %s.\\n\",\n\ 262341825Sdim return_struct.sel_addr, sel_name); \n\ 263341825Sdim } \n\ 264341825Sdim } \n\ 265341825Sdim else \n\ 266341825Sdim { \n\ 267341825Sdim return_struct.sel_addr = sel; \n\ 268341825Sdim } \n\ 269341825Sdim \n\ 270341825Sdim return_struct.impl_addr = \n\ 271341825Sdim class_getMethodImplementation (return_struct.class_addr, \n\ 272341825Sdim return_struct.sel_addr); \n\ 273341825Sdim if (debug) \n\ 274341825Sdim printf (\"\\n*** Returning implementation: 0x%p.\\n\", \n\ 275341825Sdim return_struct.impl_addr); \n\ 276341825Sdim \n\ 277341825Sdim return return_struct.impl_addr; \n\ 278341825Sdim} \n\ 279293116Semaste"; 280293116Semaste 281314564SdimAppleObjCTrampolineHandler::AppleObjCVTables::VTableRegion::VTableRegion( 282314564Sdim AppleObjCVTables *owner, lldb::addr_t header_addr) 283314564Sdim : m_valid(true), m_owner(owner), m_header_addr(header_addr), 284314564Sdim m_code_start_addr(0), m_code_end_addr(0), m_next_region(0) { 285314564Sdim SetUpRegion(); 286293116Semaste} 287293116Semaste 288314564SdimAppleObjCTrampolineHandler::~AppleObjCTrampolineHandler() {} 289293116Semaste 290314564Sdimvoid AppleObjCTrampolineHandler::AppleObjCVTables::VTableRegion::SetUpRegion() { 291314564Sdim // The header looks like: 292314564Sdim // 293314564Sdim // uint16_t headerSize 294314564Sdim // uint16_t descSize 295314564Sdim // uint32_t descCount 296314564Sdim // void * next 297314564Sdim // 298314564Sdim // First read in the header: 299293116Semaste 300314564Sdim char memory_buffer[16]; 301314564Sdim ProcessSP process_sp = m_owner->GetProcessSP(); 302314564Sdim if (!process_sp) 303314564Sdim return; 304314564Sdim DataExtractor data(memory_buffer, sizeof(memory_buffer), 305314564Sdim process_sp->GetByteOrder(), 306314564Sdim process_sp->GetAddressByteSize()); 307314564Sdim size_t actual_size = 8 + process_sp->GetAddressByteSize(); 308321369Sdim Status error; 309314564Sdim size_t bytes_read = 310314564Sdim process_sp->ReadMemory(m_header_addr, memory_buffer, actual_size, error); 311314564Sdim if (bytes_read != actual_size) { 312314564Sdim m_valid = false; 313314564Sdim return; 314314564Sdim } 315293116Semaste 316314564Sdim lldb::offset_t offset = 0; 317314564Sdim const uint16_t header_size = data.GetU16(&offset); 318314564Sdim const uint16_t descriptor_size = data.GetU16(&offset); 319314564Sdim const size_t num_descriptors = data.GetU32(&offset); 320293116Semaste 321314564Sdim m_next_region = data.GetPointer(&offset); 322314564Sdim 323314564Sdim // If the header size is 0, that means we've come in too early before this 324314564Sdim // data is set up. 325314564Sdim // Set ourselves as not valid, and continue. 326314564Sdim if (header_size == 0 || num_descriptors == 0) { 327314564Sdim m_valid = false; 328314564Sdim return; 329314564Sdim } 330314564Sdim 331314564Sdim // Now read in all the descriptors: 332314564Sdim // The descriptor looks like: 333314564Sdim // 334314564Sdim // uint32_t offset 335314564Sdim // uint32_t flags 336314564Sdim // 337341825Sdim // Where offset is either 0 - in which case it is unused, or it is 338341825Sdim // the offset of the vtable code from the beginning of the 339341825Sdim // descriptor record. Below, we'll convert that into an absolute 340341825Sdim // code address, since I don't want to have to compute it over and 341341825Sdim // over. 342314564Sdim 343314564Sdim // Ingest the whole descriptor array: 344314564Sdim const lldb::addr_t desc_ptr = m_header_addr + header_size; 345314564Sdim const size_t desc_array_size = num_descriptors * descriptor_size; 346314564Sdim DataBufferSP data_sp(new DataBufferHeap(desc_array_size, '\0')); 347314564Sdim uint8_t *dst = (uint8_t *)data_sp->GetBytes(); 348314564Sdim 349314564Sdim DataExtractor desc_extractor(dst, desc_array_size, process_sp->GetByteOrder(), 350314564Sdim process_sp->GetAddressByteSize()); 351314564Sdim bytes_read = process_sp->ReadMemory(desc_ptr, dst, desc_array_size, error); 352314564Sdim if (bytes_read != desc_array_size) { 353314564Sdim m_valid = false; 354314564Sdim return; 355314564Sdim } 356314564Sdim 357314564Sdim // The actual code for the vtables will be laid out consecutively, so I also 358314564Sdim // compute the start and end of the whole code block. 359314564Sdim 360314564Sdim offset = 0; 361314564Sdim m_code_start_addr = 0; 362314564Sdim m_code_end_addr = 0; 363314564Sdim 364314564Sdim for (size_t i = 0; i < num_descriptors; i++) { 365314564Sdim lldb::addr_t start_offset = offset; 366314564Sdim uint32_t voffset = desc_extractor.GetU32(&offset); 367314564Sdim uint32_t flags = desc_extractor.GetU32(&offset); 368314564Sdim lldb::addr_t code_addr = desc_ptr + start_offset + voffset; 369314564Sdim m_descriptors.push_back(VTableDescriptor(flags, code_addr)); 370314564Sdim 371314564Sdim if (m_code_start_addr == 0 || code_addr < m_code_start_addr) 372314564Sdim m_code_start_addr = code_addr; 373314564Sdim if (code_addr > m_code_end_addr) 374314564Sdim m_code_end_addr = code_addr; 375314564Sdim 376314564Sdim offset = start_offset + descriptor_size; 377314564Sdim } 378341825Sdim // Finally, a little bird told me that all the vtable code blocks 379341825Sdim // are the same size. Let's compute the blocks and if they are all 380341825Sdim // the same add the size to the code end address: 381314564Sdim lldb::addr_t code_size = 0; 382314564Sdim bool all_the_same = true; 383314564Sdim for (size_t i = 0; i < num_descriptors - 1; i++) { 384314564Sdim lldb::addr_t this_size = 385314564Sdim m_descriptors[i + 1].code_start - m_descriptors[i].code_start; 386314564Sdim if (code_size == 0) 387314564Sdim code_size = this_size; 388314564Sdim else { 389314564Sdim if (this_size != code_size) 390314564Sdim all_the_same = false; 391314564Sdim if (this_size > code_size) 392314564Sdim code_size = this_size; 393293116Semaste } 394314564Sdim } 395314564Sdim if (all_the_same) 396314564Sdim m_code_end_addr += code_size; 397293116Semaste} 398293116Semaste 399314564Sdimbool AppleObjCTrampolineHandler::AppleObjCVTables::VTableRegion:: 400314564Sdim AddressInRegion(lldb::addr_t addr, uint32_t &flags) { 401314564Sdim if (!IsValid()) 402293116Semaste return false; 403293116Semaste 404314564Sdim if (addr < m_code_start_addr || addr > m_code_end_addr) 405314564Sdim return false; 406314564Sdim 407314564Sdim std::vector<VTableDescriptor>::iterator pos, end = m_descriptors.end(); 408314564Sdim for (pos = m_descriptors.begin(); pos != end; pos++) { 409314564Sdim if (addr <= (*pos).code_start) { 410314564Sdim flags = (*pos).flags; 411314564Sdim return true; 412293116Semaste } 413314564Sdim } 414314564Sdim return false; 415293116Semaste} 416314564Sdim 417314564Sdimvoid AppleObjCTrampolineHandler::AppleObjCVTables::VTableRegion::Dump( 418314564Sdim Stream &s) { 419314564Sdim s.Printf("Header addr: 0x%" PRIx64 " Code start: 0x%" PRIx64 420314564Sdim " Code End: 0x%" PRIx64 " Next: 0x%" PRIx64 "\n", 421314564Sdim m_header_addr, m_code_start_addr, m_code_end_addr, m_next_region); 422314564Sdim size_t num_elements = m_descriptors.size(); 423314564Sdim for (size_t i = 0; i < num_elements; i++) { 424314564Sdim s.Indent(); 425314564Sdim s.Printf("Code start: 0x%" PRIx64 " Flags: %d\n", 426314564Sdim m_descriptors[i].code_start, m_descriptors[i].flags); 427314564Sdim } 428293116Semaste} 429293116Semaste 430314564SdimAppleObjCTrampolineHandler::AppleObjCVTables::AppleObjCVTables( 431314564Sdim const ProcessSP &process_sp, const ModuleSP &objc_module_sp) 432314564Sdim : m_process_wp(), m_trampoline_header(LLDB_INVALID_ADDRESS), 433314564Sdim m_trampolines_changed_bp_id(LLDB_INVALID_BREAK_ID), 434314564Sdim m_objc_module_sp(objc_module_sp) { 435314564Sdim if (process_sp) 436314564Sdim m_process_wp = process_sp; 437293116Semaste} 438293116Semaste 439314564SdimAppleObjCTrampolineHandler::AppleObjCVTables::~AppleObjCVTables() { 440314564Sdim ProcessSP process_sp = GetProcessSP(); 441314564Sdim if (process_sp) { 442314564Sdim if (m_trampolines_changed_bp_id != LLDB_INVALID_BREAK_ID) 443314564Sdim process_sp->GetTarget().RemoveBreakpointByID(m_trampolines_changed_bp_id); 444314564Sdim } 445314564Sdim} 446293116Semaste 447314564Sdimbool AppleObjCTrampolineHandler::AppleObjCVTables::InitializeVTableSymbols() { 448314564Sdim if (m_trampoline_header != LLDB_INVALID_ADDRESS) 449314564Sdim return true; 450314564Sdim 451314564Sdim ProcessSP process_sp = GetProcessSP(); 452314564Sdim if (process_sp) { 453314564Sdim Target &target = process_sp->GetTarget(); 454314564Sdim 455314564Sdim const ModuleList &target_modules = target.GetImages(); 456314564Sdim std::lock_guard<std::recursive_mutex> guard(target_modules.GetMutex()); 457314564Sdim size_t num_modules = target_modules.GetSize(); 458314564Sdim if (!m_objc_module_sp) { 459314564Sdim for (size_t i = 0; i < num_modules; i++) { 460314564Sdim if (process_sp->GetObjCLanguageRuntime()->IsModuleObjCLibrary( 461314564Sdim target_modules.GetModuleAtIndexUnlocked(i))) { 462314564Sdim m_objc_module_sp = target_modules.GetModuleAtIndexUnlocked(i); 463314564Sdim break; 464293116Semaste } 465314564Sdim } 466314564Sdim } 467314564Sdim 468314564Sdim if (m_objc_module_sp) { 469314564Sdim ConstString trampoline_name("gdb_objc_trampolines"); 470314564Sdim const Symbol *trampoline_symbol = 471314564Sdim m_objc_module_sp->FindFirstSymbolWithNameAndType(trampoline_name, 472314564Sdim eSymbolTypeData); 473314564Sdim if (trampoline_symbol != NULL) { 474314564Sdim m_trampoline_header = trampoline_symbol->GetLoadAddress(&target); 475314564Sdim if (m_trampoline_header == LLDB_INVALID_ADDRESS) 476314564Sdim return false; 477314564Sdim 478314564Sdim // Next look up the "changed" symbol and set a breakpoint on that... 479314564Sdim ConstString changed_name("gdb_objc_trampolines_changed"); 480314564Sdim const Symbol *changed_symbol = 481314564Sdim m_objc_module_sp->FindFirstSymbolWithNameAndType(changed_name, 482314564Sdim eSymbolTypeCode); 483314564Sdim if (changed_symbol != NULL) { 484314564Sdim const Address changed_symbol_addr = changed_symbol->GetAddress(); 485314564Sdim if (!changed_symbol_addr.IsValid()) 486314564Sdim return false; 487314564Sdim 488314564Sdim lldb::addr_t changed_addr = 489314564Sdim changed_symbol_addr.GetOpcodeLoadAddress(&target); 490314564Sdim if (changed_addr != LLDB_INVALID_ADDRESS) { 491314564Sdim BreakpointSP trampolines_changed_bp_sp = 492314564Sdim target.CreateBreakpoint(changed_addr, true, false); 493314564Sdim if (trampolines_changed_bp_sp) { 494314564Sdim m_trampolines_changed_bp_id = trampolines_changed_bp_sp->GetID(); 495314564Sdim trampolines_changed_bp_sp->SetCallback(RefreshTrampolines, this, 496314564Sdim true); 497314564Sdim trampolines_changed_bp_sp->SetBreakpointKind( 498314564Sdim "objc-trampolines-changed"); 499314564Sdim return true; 500293116Semaste } 501314564Sdim } 502293116Semaste } 503314564Sdim } 504293116Semaste } 505314564Sdim } 506314564Sdim return false; 507293116Semaste} 508293116Semaste 509314564Sdimbool AppleObjCTrampolineHandler::AppleObjCVTables::RefreshTrampolines( 510314564Sdim void *baton, StoppointCallbackContext *context, lldb::user_id_t break_id, 511314564Sdim lldb::user_id_t break_loc_id) { 512314564Sdim AppleObjCVTables *vtable_handler = (AppleObjCVTables *)baton; 513314564Sdim if (vtable_handler->InitializeVTableSymbols()) { 514314564Sdim // The Update function is called with the address of an added region. So we 515314564Sdim // grab that address, and 516314564Sdim // feed it into ReadRegions. Of course, our friend the ABI will get the 517314564Sdim // values for us. 518314564Sdim ExecutionContext exe_ctx(context->exe_ctx_ref); 519314564Sdim Process *process = exe_ctx.GetProcessPtr(); 520314564Sdim const ABI *abi = process->GetABI().get(); 521314564Sdim 522314564Sdim ClangASTContext *clang_ast_context = 523314564Sdim process->GetTarget().GetScratchClangASTContext(); 524314564Sdim ValueList argument_values; 525314564Sdim Value input_value; 526314564Sdim CompilerType clang_void_ptr_type = 527314564Sdim clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 528314564Sdim 529314564Sdim input_value.SetValueType(Value::eValueTypeScalar); 530314564Sdim // input_value.SetContext (Value::eContextTypeClangType, 531314564Sdim // clang_void_ptr_type); 532314564Sdim input_value.SetCompilerType(clang_void_ptr_type); 533314564Sdim argument_values.PushValue(input_value); 534314564Sdim 535314564Sdim bool success = 536314564Sdim abi->GetArgumentValues(exe_ctx.GetThreadRef(), argument_values); 537314564Sdim if (!success) 538314564Sdim return false; 539314564Sdim 540314564Sdim // Now get a pointer value from the zeroth argument. 541321369Sdim Status error; 542314564Sdim DataExtractor data; 543314564Sdim error = argument_values.GetValueAtIndex(0)->GetValueAsData(&exe_ctx, data, 544314564Sdim 0, NULL); 545314564Sdim lldb::offset_t offset = 0; 546314564Sdim lldb::addr_t region_addr = data.GetPointer(&offset); 547314564Sdim 548314564Sdim if (region_addr != 0) 549314564Sdim vtable_handler->ReadRegions(region_addr); 550314564Sdim } 551314564Sdim return false; 552293116Semaste} 553293116Semaste 554314564Sdimbool AppleObjCTrampolineHandler::AppleObjCVTables::ReadRegions() { 555341825Sdim // The no argument version reads the start region from the value of 556341825Sdim // the gdb_regions_header, and gets started from there. 557314564Sdim 558314564Sdim m_regions.clear(); 559314564Sdim if (!InitializeVTableSymbols()) 560293116Semaste return false; 561321369Sdim Status error; 562314564Sdim ProcessSP process_sp = GetProcessSP(); 563314564Sdim if (process_sp) { 564314564Sdim lldb::addr_t region_addr = 565314564Sdim process_sp->ReadPointerFromMemory(m_trampoline_header, error); 566314564Sdim if (error.Success()) 567314564Sdim return ReadRegions(region_addr); 568314564Sdim } 569314564Sdim return false; 570293116Semaste} 571293116Semaste 572314564Sdimbool AppleObjCTrampolineHandler::AppleObjCVTables::ReadRegions( 573314564Sdim lldb::addr_t region_addr) { 574314564Sdim ProcessSP process_sp = GetProcessSP(); 575314564Sdim if (!process_sp) 576314564Sdim return false; 577314564Sdim 578314564Sdim Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); 579314564Sdim 580314564Sdim // We aren't starting at the trampoline symbol. 581314564Sdim InitializeVTableSymbols(); 582314564Sdim lldb::addr_t next_region = region_addr; 583314564Sdim 584314564Sdim // Read in the sizes of the headers. 585314564Sdim while (next_region != 0) { 586314564Sdim m_regions.push_back(VTableRegion(this, next_region)); 587314564Sdim if (!m_regions.back().IsValid()) { 588314564Sdim m_regions.clear(); 589314564Sdim return false; 590293116Semaste } 591314564Sdim if (log) { 592314564Sdim StreamString s; 593314564Sdim m_regions.back().Dump(s); 594314564Sdim log->Printf("Read vtable region: \n%s", s.GetData()); 595293116Semaste } 596314564Sdim 597314564Sdim next_region = m_regions.back().GetNextRegionAddr(); 598314564Sdim } 599314564Sdim 600314564Sdim return true; 601293116Semaste} 602293116Semaste 603314564Sdimbool AppleObjCTrampolineHandler::AppleObjCVTables::IsAddressInVTables( 604314564Sdim lldb::addr_t addr, uint32_t &flags) { 605314564Sdim region_collection::iterator pos, end = m_regions.end(); 606314564Sdim for (pos = m_regions.begin(); pos != end; pos++) { 607314564Sdim if ((*pos).AddressInRegion(addr, flags)) 608314564Sdim return true; 609314564Sdim } 610314564Sdim return false; 611314564Sdim} 612314564Sdim 613293116Semasteconst AppleObjCTrampolineHandler::DispatchFunction 614314564Sdim AppleObjCTrampolineHandler::g_dispatch_functions[] = { 615314564Sdim // NAME STRET SUPER SUPER2 FIXUP TYPE 616314564Sdim {"objc_msgSend", false, false, false, DispatchFunction::eFixUpNone}, 617314564Sdim {"objc_msgSend_fixup", false, false, false, 618314564Sdim DispatchFunction::eFixUpToFix}, 619314564Sdim {"objc_msgSend_fixedup", false, false, false, 620314564Sdim DispatchFunction::eFixUpFixed}, 621314564Sdim {"objc_msgSend_stret", true, false, false, 622314564Sdim DispatchFunction::eFixUpNone}, 623314564Sdim {"objc_msgSend_stret_fixup", true, false, false, 624314564Sdim DispatchFunction::eFixUpToFix}, 625314564Sdim {"objc_msgSend_stret_fixedup", true, false, false, 626314564Sdim DispatchFunction::eFixUpFixed}, 627314564Sdim {"objc_msgSend_fpret", false, false, false, 628314564Sdim DispatchFunction::eFixUpNone}, 629314564Sdim {"objc_msgSend_fpret_fixup", false, false, false, 630314564Sdim DispatchFunction::eFixUpToFix}, 631314564Sdim {"objc_msgSend_fpret_fixedup", false, false, false, 632314564Sdim DispatchFunction::eFixUpFixed}, 633314564Sdim {"objc_msgSend_fp2ret", false, false, true, 634314564Sdim DispatchFunction::eFixUpNone}, 635314564Sdim {"objc_msgSend_fp2ret_fixup", false, false, true, 636314564Sdim DispatchFunction::eFixUpToFix}, 637314564Sdim {"objc_msgSend_fp2ret_fixedup", false, false, true, 638314564Sdim DispatchFunction::eFixUpFixed}, 639314564Sdim {"objc_msgSendSuper", false, true, false, DispatchFunction::eFixUpNone}, 640314564Sdim {"objc_msgSendSuper_stret", true, true, false, 641314564Sdim DispatchFunction::eFixUpNone}, 642314564Sdim {"objc_msgSendSuper2", false, true, true, DispatchFunction::eFixUpNone}, 643314564Sdim {"objc_msgSendSuper2_fixup", false, true, true, 644314564Sdim DispatchFunction::eFixUpToFix}, 645314564Sdim {"objc_msgSendSuper2_fixedup", false, true, true, 646314564Sdim DispatchFunction::eFixUpFixed}, 647314564Sdim {"objc_msgSendSuper2_stret", true, true, true, 648314564Sdim DispatchFunction::eFixUpNone}, 649314564Sdim {"objc_msgSendSuper2_stret_fixup", true, true, true, 650314564Sdim DispatchFunction::eFixUpToFix}, 651314564Sdim {"objc_msgSendSuper2_stret_fixedup", true, true, true, 652314564Sdim DispatchFunction::eFixUpFixed}, 653293116Semaste}; 654293116Semaste 655314564SdimAppleObjCTrampolineHandler::AppleObjCTrampolineHandler( 656314564Sdim const ProcessSP &process_sp, const ModuleSP &objc_module_sp) 657314564Sdim : m_process_wp(), m_objc_module_sp(objc_module_sp), 658314564Sdim m_lookup_implementation_function_code(nullptr), 659314564Sdim m_impl_fn_addr(LLDB_INVALID_ADDRESS), 660314564Sdim m_impl_stret_fn_addr(LLDB_INVALID_ADDRESS), 661314564Sdim m_msg_forward_addr(LLDB_INVALID_ADDRESS) { 662314564Sdim if (process_sp) 663314564Sdim m_process_wp = process_sp; 664314564Sdim // Look up the known resolution functions: 665314564Sdim 666314564Sdim ConstString get_impl_name("class_getMethodImplementation"); 667314564Sdim ConstString get_impl_stret_name("class_getMethodImplementation_stret"); 668314564Sdim ConstString msg_forward_name("_objc_msgForward"); 669314564Sdim ConstString msg_forward_stret_name("_objc_msgForward_stret"); 670314564Sdim 671314564Sdim Target *target = process_sp ? &process_sp->GetTarget() : NULL; 672314564Sdim const Symbol *class_getMethodImplementation = 673314564Sdim m_objc_module_sp->FindFirstSymbolWithNameAndType(get_impl_name, 674314564Sdim eSymbolTypeCode); 675314564Sdim const Symbol *class_getMethodImplementation_stret = 676314564Sdim m_objc_module_sp->FindFirstSymbolWithNameAndType(get_impl_stret_name, 677314564Sdim eSymbolTypeCode); 678314564Sdim const Symbol *msg_forward = m_objc_module_sp->FindFirstSymbolWithNameAndType( 679314564Sdim msg_forward_name, eSymbolTypeCode); 680314564Sdim const Symbol *msg_forward_stret = 681314564Sdim m_objc_module_sp->FindFirstSymbolWithNameAndType(msg_forward_stret_name, 682314564Sdim eSymbolTypeCode); 683314564Sdim 684314564Sdim if (class_getMethodImplementation) 685314564Sdim m_impl_fn_addr = 686314564Sdim class_getMethodImplementation->GetAddress().GetOpcodeLoadAddress( 687314564Sdim target); 688314564Sdim if (class_getMethodImplementation_stret) 689314564Sdim m_impl_stret_fn_addr = 690314564Sdim class_getMethodImplementation_stret->GetAddress().GetOpcodeLoadAddress( 691314564Sdim target); 692314564Sdim if (msg_forward) 693314564Sdim m_msg_forward_addr = msg_forward->GetAddress().GetOpcodeLoadAddress(target); 694314564Sdim if (msg_forward_stret) 695314564Sdim m_msg_forward_stret_addr = 696314564Sdim msg_forward_stret->GetAddress().GetOpcodeLoadAddress(target); 697314564Sdim 698314564Sdim // FIXME: Do some kind of logging here. 699314564Sdim if (m_impl_fn_addr == LLDB_INVALID_ADDRESS) { 700314564Sdim // If we can't even find the ordinary get method implementation function, 701314564Sdim // then we aren't going to be able to 702314564Sdim // step through any method dispatches. Warn to that effect and get out of 703314564Sdim // here. 704314564Sdim if (process_sp->CanJIT()) { 705314564Sdim process_sp->GetTarget().GetDebugger().GetErrorFile()->Printf( 706314564Sdim "Could not find implementation lookup function \"%s\"" 707314564Sdim " step in through ObjC method dispatch will not work.\n", 708314564Sdim get_impl_name.AsCString()); 709293116Semaste } 710314564Sdim return; 711314564Sdim } else if (m_impl_stret_fn_addr == LLDB_INVALID_ADDRESS) { 712314564Sdim // It there is no stret return lookup function, assume that it is the same 713314564Sdim // as the straight lookup: 714314564Sdim m_impl_stret_fn_addr = m_impl_fn_addr; 715314564Sdim // Also we will use the version of the lookup code that doesn't rely on the 716314564Sdim // stret version of the function. 717314564Sdim m_lookup_implementation_function_code = 718314564Sdim g_lookup_implementation_no_stret_function_code; 719314564Sdim } else { 720314564Sdim m_lookup_implementation_function_code = 721314564Sdim g_lookup_implementation_with_stret_function_code; 722314564Sdim } 723314564Sdim 724341825Sdim // Look up the addresses for the objc dispatch functions and cache 725341825Sdim // them. For now I'm inspecting the symbol names dynamically to 726341825Sdim // figure out how to dispatch to them. If it becomes more 727341825Sdim // complicated than this we can turn the g_dispatch_functions char * 728341825Sdim // array into a template table, and populate the DispatchFunction 729341825Sdim // map from there. 730314564Sdim 731314564Sdim for (size_t i = 0; i != llvm::array_lengthof(g_dispatch_functions); i++) { 732314564Sdim ConstString name_const_str(g_dispatch_functions[i].name); 733314564Sdim const Symbol *msgSend_symbol = 734314564Sdim m_objc_module_sp->FindFirstSymbolWithNameAndType(name_const_str, 735314564Sdim eSymbolTypeCode); 736314564Sdim if (msgSend_symbol && msgSend_symbol->ValueIsAddress()) { 737341825Sdim // FIXME: Make g_dispatch_functions static table of 738341825Sdim // DispatchFunctions, and have the map be address->index. 739341825Sdim // Problem is we also need to lookup the dispatch function. For 740341825Sdim // now we could have a side table of stret & non-stret dispatch 741341825Sdim // functions. If that's as complex as it gets, we're fine. 742314564Sdim 743314564Sdim lldb::addr_t sym_addr = 744314564Sdim msgSend_symbol->GetAddressRef().GetOpcodeLoadAddress(target); 745314564Sdim 746314564Sdim m_msgSend_map.insert(std::pair<lldb::addr_t, int>(sym_addr, i)); 747293116Semaste } 748314564Sdim } 749293116Semaste 750314564Sdim // Build our vtable dispatch handler here: 751314564Sdim m_vtables_ap.reset(new AppleObjCVTables(process_sp, m_objc_module_sp)); 752314564Sdim if (m_vtables_ap.get()) 753314564Sdim m_vtables_ap->ReadRegions(); 754293116Semaste} 755293116Semaste 756293116Semastelldb::addr_t 757314564SdimAppleObjCTrampolineHandler::SetupDispatchFunction(Thread &thread, 758314564Sdim ValueList &dispatch_values) { 759314564Sdim ThreadSP thread_sp(thread.shared_from_this()); 760314564Sdim ExecutionContext exe_ctx(thread_sp); 761314564Sdim DiagnosticManager diagnostics; 762314564Sdim Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); 763309124Sdim 764314564Sdim lldb::addr_t args_addr = LLDB_INVALID_ADDRESS; 765314564Sdim FunctionCaller *impl_function_caller = nullptr; 766293116Semaste 767314564Sdim // Scope for mutex locker: 768314564Sdim { 769314564Sdim std::lock_guard<std::mutex> guard(m_impl_function_mutex); 770309124Sdim 771314564Sdim // First stage is to make the ClangUtility to hold our injected function: 772293116Semaste 773314564Sdim if (!m_impl_code.get()) { 774314564Sdim if (m_lookup_implementation_function_code != NULL) { 775321369Sdim Status error; 776314564Sdim m_impl_code.reset(exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage( 777314564Sdim m_lookup_implementation_function_code, eLanguageTypeObjC, 778314564Sdim g_lookup_implementation_function_name, error)); 779314564Sdim if (error.Fail()) { 780314564Sdim if (log) 781314564Sdim log->Printf( 782314564Sdim "Failed to get Utility Function for implementation lookup: %s.", 783314564Sdim error.AsCString()); 784314564Sdim m_impl_code.reset(); 785314564Sdim return args_addr; 786314564Sdim } 787309124Sdim 788314564Sdim if (!m_impl_code->Install(diagnostics, exe_ctx)) { 789314564Sdim if (log) { 790314564Sdim log->Printf("Failed to install implementation lookup."); 791314564Sdim diagnostics.Dump(log); 792314564Sdim } 793314564Sdim m_impl_code.reset(); 794314564Sdim return args_addr; 795293116Semaste } 796314564Sdim } else { 797314564Sdim if (log) 798314564Sdim log->Printf("No method lookup implementation code."); 799314564Sdim return LLDB_INVALID_ADDRESS; 800314564Sdim } 801309124Sdim 802314564Sdim // Next make the runner function for our implementation utility function. 803314564Sdim ClangASTContext *clang_ast_context = 804314564Sdim thread.GetProcess()->GetTarget().GetScratchClangASTContext(); 805314564Sdim CompilerType clang_void_ptr_type = 806314564Sdim clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 807321369Sdim Status error; 808309124Sdim 809314564Sdim impl_function_caller = m_impl_code->MakeFunctionCaller( 810314564Sdim clang_void_ptr_type, dispatch_values, thread_sp, error); 811314564Sdim if (error.Fail()) { 812293116Semaste if (log) 813314564Sdim log->Printf( 814314564Sdim "Error getting function caller for dispatch lookup: \"%s\".", 815314564Sdim error.AsCString()); 816293116Semaste return args_addr; 817314564Sdim } 818314564Sdim } else { 819314564Sdim impl_function_caller = m_impl_code->GetFunctionCaller(); 820293116Semaste } 821314564Sdim } 822309124Sdim 823314564Sdim diagnostics.Clear(); 824314564Sdim 825341825Sdim // Now write down the argument values for this particular call. 826341825Sdim // This looks like it might be a race condition if other threads 827341825Sdim // were calling into here, but actually it isn't because we allocate 828341825Sdim // a new args structure for this call by passing args_addr = 829341825Sdim // LLDB_INVALID_ADDRESS... 830314564Sdim 831314564Sdim if (!impl_function_caller->WriteFunctionArguments( 832314564Sdim exe_ctx, args_addr, dispatch_values, diagnostics)) { 833314564Sdim if (log) { 834314564Sdim log->Printf("Error writing function arguments."); 835314564Sdim diagnostics.Dump(log); 836314564Sdim } 837293116Semaste return args_addr; 838314564Sdim } 839314564Sdim 840314564Sdim return args_addr; 841293116Semaste} 842293116Semaste 843293116SemasteThreadPlanSP 844314564SdimAppleObjCTrampolineHandler::GetStepThroughDispatchPlan(Thread &thread, 845314564Sdim bool stop_others) { 846314564Sdim ThreadPlanSP ret_plan_sp; 847314564Sdim lldb::addr_t curr_pc = thread.GetRegisterContext()->GetPC(); 848314564Sdim 849314564Sdim DispatchFunction this_dispatch; 850314564Sdim bool found_it = false; 851314564Sdim 852341825Sdim // First step is to look and see if we are in one of the known ObjC 853341825Sdim // dispatch functions. We've already compiled a table of same, so 854341825Sdim // consult it. 855314564Sdim 856314564Sdim MsgsendMap::iterator pos; 857314564Sdim pos = m_msgSend_map.find(curr_pc); 858314564Sdim if (pos != m_msgSend_map.end()) { 859314564Sdim this_dispatch = g_dispatch_functions[(*pos).second]; 860314564Sdim found_it = true; 861314564Sdim } 862314564Sdim 863314564Sdim // Next check to see if we are in a vtable region: 864314564Sdim 865314564Sdim if (!found_it) { 866314564Sdim uint32_t flags; 867314564Sdim if (m_vtables_ap.get()) { 868314564Sdim found_it = m_vtables_ap->IsAddressInVTables(curr_pc, flags); 869314564Sdim if (found_it) { 870314564Sdim this_dispatch.name = "vtable"; 871314564Sdim this_dispatch.stret_return = 872314564Sdim (flags & AppleObjCVTables::eOBJC_TRAMPOLINE_STRET) == 873314564Sdim AppleObjCVTables::eOBJC_TRAMPOLINE_STRET; 874314564Sdim this_dispatch.is_super = false; 875314564Sdim this_dispatch.is_super2 = false; 876314564Sdim this_dispatch.fixedup = DispatchFunction::eFixUpFixed; 877314564Sdim } 878293116Semaste } 879314564Sdim } 880314564Sdim 881314564Sdim if (found_it) { 882314564Sdim Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); 883314564Sdim 884341825Sdim // We are decoding a method dispatch. First job is to pull the 885341825Sdim // arguments out: 886314564Sdim 887314564Sdim lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0); 888314564Sdim 889314564Sdim const ABI *abi = NULL; 890314564Sdim ProcessSP process_sp(thread.CalculateProcess()); 891314564Sdim if (process_sp) 892314564Sdim abi = process_sp->GetABI().get(); 893314564Sdim if (abi == NULL) 894314564Sdim return ret_plan_sp; 895314564Sdim 896314564Sdim TargetSP target_sp(thread.CalculateTarget()); 897314564Sdim 898314564Sdim ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext(); 899314564Sdim ValueList argument_values; 900314564Sdim Value void_ptr_value; 901314564Sdim CompilerType clang_void_ptr_type = 902314564Sdim clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType(); 903314564Sdim void_ptr_value.SetValueType(Value::eValueTypeScalar); 904314564Sdim // void_ptr_value.SetContext (Value::eContextTypeClangType, 905314564Sdim // clang_void_ptr_type); 906314564Sdim void_ptr_value.SetCompilerType(clang_void_ptr_type); 907314564Sdim 908314564Sdim int obj_index; 909314564Sdim int sel_index; 910314564Sdim 911341825Sdim // If this is a struct return dispatch, then the first argument is 912341825Sdim // the return struct pointer, and the object is the second, and 913341825Sdim // the selector is the third. Otherwise the object is the first 914341825Sdim // and the selector the second. 915314564Sdim if (this_dispatch.stret_return) { 916314564Sdim obj_index = 1; 917314564Sdim sel_index = 2; 918314564Sdim argument_values.PushValue(void_ptr_value); 919314564Sdim argument_values.PushValue(void_ptr_value); 920314564Sdim argument_values.PushValue(void_ptr_value); 921314564Sdim } else { 922314564Sdim obj_index = 0; 923314564Sdim sel_index = 1; 924314564Sdim argument_values.PushValue(void_ptr_value); 925314564Sdim argument_values.PushValue(void_ptr_value); 926293116Semaste } 927293116Semaste 928314564Sdim bool success = abi->GetArgumentValues(thread, argument_values); 929314564Sdim if (!success) 930314564Sdim return ret_plan_sp; 931293116Semaste 932314564Sdim lldb::addr_t obj_addr = 933314564Sdim argument_values.GetValueAtIndex(obj_index)->GetScalar().ULongLong(); 934314564Sdim if (obj_addr == 0x0) { 935314564Sdim if (log) 936314564Sdim log->Printf( 937314564Sdim "Asked to step to dispatch to nil object, returning empty plan."); 938314564Sdim return ret_plan_sp; 939314564Sdim } 940314564Sdim 941314564Sdim ExecutionContext exe_ctx(thread.shared_from_this()); 942314564Sdim Process *process = exe_ctx.GetProcessPtr(); 943341825Sdim // isa_addr will store the class pointer that the method is being 944341825Sdim // dispatched to - so either the class directly or the super class 945341825Sdim // if this is one of the objc_msgSendSuper flavors. That's mostly 946341825Sdim // used to look up the class/selector pair in our cache. 947314564Sdim 948314564Sdim lldb::addr_t isa_addr = LLDB_INVALID_ADDRESS; 949314564Sdim lldb::addr_t sel_addr = 950314564Sdim argument_values.GetValueAtIndex(sel_index)->GetScalar().ULongLong(); 951314564Sdim 952341825Sdim // Figure out the class this is being dispatched to and see if 953341825Sdim // we've already cached this method call, If so we can push a 954341825Sdim // run-to-address plan directly. Otherwise we have to figure out 955341825Sdim // where the implementation lives. 956314564Sdim 957314564Sdim if (this_dispatch.is_super) { 958314564Sdim if (this_dispatch.is_super2) { 959341825Sdim // In the objc_msgSendSuper2 case, we don't get the object 960341825Sdim // directly, we get a structure containing the object and the 961341825Sdim // class to which the super message is being sent. So we need 962341825Sdim // to dig the super out of the class and use that. 963314564Sdim 964314564Sdim Value super_value(*(argument_values.GetValueAtIndex(obj_index))); 965314564Sdim super_value.GetScalar() += process->GetAddressByteSize(); 966314564Sdim super_value.ResolveValue(&exe_ctx); 967314564Sdim 968314564Sdim if (super_value.GetScalar().IsValid()) { 969314564Sdim 970314564Sdim // isa_value now holds the class pointer. The second word of the 971314564Sdim // class pointer is the super-class pointer: 972314564Sdim super_value.GetScalar() += process->GetAddressByteSize(); 973314564Sdim super_value.ResolveValue(&exe_ctx); 974314564Sdim if (super_value.GetScalar().IsValid()) 975314564Sdim isa_addr = super_value.GetScalar().ULongLong(); 976314564Sdim else { 977293116Semaste if (log) 978314564Sdim log->Printf("Failed to extract the super class value from the " 979314564Sdim "class in objc_super."); 980314564Sdim } 981314564Sdim } else { 982314564Sdim if (log) 983314564Sdim log->Printf("Failed to extract the class value from objc_super."); 984293116Semaste } 985314564Sdim } else { 986341825Sdim // In the objc_msgSendSuper case, we don't get the object 987341825Sdim // directly, we get a two element structure containing the 988341825Sdim // object and the super class to which the super message is 989341825Sdim // being sent. So the class we want is the second element of 990341825Sdim // this structure. 991293116Semaste 992314564Sdim Value super_value(*(argument_values.GetValueAtIndex(obj_index))); 993314564Sdim super_value.GetScalar() += process->GetAddressByteSize(); 994314564Sdim super_value.ResolveValue(&exe_ctx); 995314564Sdim 996314564Sdim if (super_value.GetScalar().IsValid()) { 997314564Sdim isa_addr = super_value.GetScalar().ULongLong(); 998314564Sdim } else { 999314564Sdim if (log) 1000314564Sdim log->Printf("Failed to extract the class value from objc_super."); 1001293116Semaste } 1002314564Sdim } 1003314564Sdim } else { 1004314564Sdim // In the direct dispatch case, the object->isa is the class pointer we 1005314564Sdim // want. 1006293116Semaste 1007314564Sdim // This is a little cheesy, but since object->isa is the first field, 1008314564Sdim // making the object value a load address value and resolving it will get 1009314564Sdim // the pointer sized data pointed to by that value... 1010293116Semaste 1011341825Sdim // Note, it isn't a fatal error not to be able to get the 1012341825Sdim // address from the object, since this might be a "tagged 1013341825Sdim // pointer" which isn't a real object, but rather some word 1014314564Sdim // length encoded dingus. 1015314564Sdim 1016314564Sdim Value isa_value(*(argument_values.GetValueAtIndex(obj_index))); 1017314564Sdim 1018314564Sdim isa_value.SetValueType(Value::eValueTypeLoadAddress); 1019314564Sdim isa_value.ResolveValue(&exe_ctx); 1020314564Sdim if (isa_value.GetScalar().IsValid()) { 1021314564Sdim isa_addr = isa_value.GetScalar().ULongLong(); 1022314564Sdim } else { 1023314564Sdim if (log) 1024314564Sdim log->Printf("Failed to extract the isa value from object."); 1025314564Sdim } 1026293116Semaste } 1027314564Sdim 1028314564Sdim // Okay, we've got the address of the class for which we're resolving this, 1029314564Sdim // let's see if it's in our cache: 1030314564Sdim lldb::addr_t impl_addr = LLDB_INVALID_ADDRESS; 1031314564Sdim 1032314564Sdim if (isa_addr != LLDB_INVALID_ADDRESS) { 1033314564Sdim if (log) { 1034314564Sdim log->Printf("Resolving call for class - 0x%" PRIx64 1035314564Sdim " and selector - 0x%" PRIx64, 1036314564Sdim isa_addr, sel_addr); 1037314564Sdim } 1038314564Sdim ObjCLanguageRuntime *objc_runtime = 1039314564Sdim thread.GetProcess()->GetObjCLanguageRuntime(); 1040314564Sdim assert(objc_runtime != NULL); 1041314564Sdim 1042314564Sdim impl_addr = objc_runtime->LookupInMethodCache(isa_addr, sel_addr); 1043314564Sdim } 1044314564Sdim 1045314564Sdim if (impl_addr != LLDB_INVALID_ADDRESS) { 1046314564Sdim // Yup, it was in the cache, so we can run to that address directly. 1047314564Sdim 1048314564Sdim if (log) 1049314564Sdim log->Printf("Found implementation address in cache: 0x%" PRIx64, 1050314564Sdim impl_addr); 1051314564Sdim 1052314564Sdim ret_plan_sp.reset( 1053314564Sdim new ThreadPlanRunToAddress(thread, impl_addr, stop_others)); 1054314564Sdim } else { 1055314564Sdim // We haven't seen this class/selector pair yet. Look it up. 1056314564Sdim StreamString errors; 1057314564Sdim Address impl_code_address; 1058314564Sdim 1059314564Sdim ValueList dispatch_values; 1060314564Sdim 1061314564Sdim // We've will inject a little function in the target that takes the 1062314564Sdim // object, selector and some flags, 1063314564Sdim // and figures out the implementation. Looks like: 1064314564Sdim // void *__lldb_objc_find_implementation_for_selector (void *object, 1065314564Sdim // void *sel, 1066314564Sdim // int is_stret, 1067314564Sdim // int is_super, 1068314564Sdim // int is_super2, 1069314564Sdim // int is_fixup, 1070314564Sdim // int is_fixed, 1071314564Sdim // int debug) 1072314564Sdim // So set up the arguments for that call. 1073314564Sdim 1074314564Sdim dispatch_values.PushValue(*(argument_values.GetValueAtIndex(obj_index))); 1075314564Sdim dispatch_values.PushValue(*(argument_values.GetValueAtIndex(sel_index))); 1076314564Sdim 1077314564Sdim Value flag_value; 1078314564Sdim CompilerType clang_int_type = 1079314564Sdim clang_ast_context->GetBuiltinTypeForEncodingAndBitSize( 1080314564Sdim lldb::eEncodingSint, 32); 1081314564Sdim flag_value.SetValueType(Value::eValueTypeScalar); 1082314564Sdim // flag_value.SetContext (Value::eContextTypeClangType, clang_int_type); 1083314564Sdim flag_value.SetCompilerType(clang_int_type); 1084314564Sdim 1085314564Sdim if (this_dispatch.stret_return) 1086314564Sdim flag_value.GetScalar() = 1; 1087314564Sdim else 1088314564Sdim flag_value.GetScalar() = 0; 1089314564Sdim dispatch_values.PushValue(flag_value); 1090314564Sdim 1091314564Sdim if (this_dispatch.is_super) 1092314564Sdim flag_value.GetScalar() = 1; 1093314564Sdim else 1094314564Sdim flag_value.GetScalar() = 0; 1095314564Sdim dispatch_values.PushValue(flag_value); 1096314564Sdim 1097314564Sdim if (this_dispatch.is_super2) 1098314564Sdim flag_value.GetScalar() = 1; 1099314564Sdim else 1100314564Sdim flag_value.GetScalar() = 0; 1101314564Sdim dispatch_values.PushValue(flag_value); 1102314564Sdim 1103314564Sdim switch (this_dispatch.fixedup) { 1104314564Sdim case DispatchFunction::eFixUpNone: 1105314564Sdim flag_value.GetScalar() = 0; 1106314564Sdim dispatch_values.PushValue(flag_value); 1107314564Sdim dispatch_values.PushValue(flag_value); 1108314564Sdim break; 1109314564Sdim case DispatchFunction::eFixUpFixed: 1110314564Sdim flag_value.GetScalar() = 1; 1111314564Sdim dispatch_values.PushValue(flag_value); 1112314564Sdim flag_value.GetScalar() = 1; 1113314564Sdim dispatch_values.PushValue(flag_value); 1114314564Sdim break; 1115314564Sdim case DispatchFunction::eFixUpToFix: 1116314564Sdim flag_value.GetScalar() = 1; 1117314564Sdim dispatch_values.PushValue(flag_value); 1118314564Sdim flag_value.GetScalar() = 0; 1119314564Sdim dispatch_values.PushValue(flag_value); 1120314564Sdim break; 1121314564Sdim } 1122314564Sdim if (log && log->GetVerbose()) 1123314564Sdim flag_value.GetScalar() = 1; 1124314564Sdim else 1125314564Sdim flag_value.GetScalar() = 0; // FIXME - Set to 0 when debugging is done. 1126314564Sdim dispatch_values.PushValue(flag_value); 1127314564Sdim 1128341825Sdim // The step through code might have to fill in the cache, so it 1129341825Sdim // is not safe to run only one thread. So we override the 1130341825Sdim // stop_others value passed in to us here: 1131314564Sdim const bool trampoline_stop_others = false; 1132314564Sdim ret_plan_sp.reset(new AppleThreadPlanStepThroughObjCTrampoline( 1133314564Sdim thread, this, dispatch_values, isa_addr, sel_addr, 1134314564Sdim trampoline_stop_others)); 1135314564Sdim if (log) { 1136314564Sdim StreamString s; 1137314564Sdim ret_plan_sp->GetDescription(&s, eDescriptionLevelFull); 1138314564Sdim log->Printf("Using ObjC step plan: %s.\n", s.GetData()); 1139314564Sdim } 1140314564Sdim } 1141314564Sdim } 1142314564Sdim 1143314564Sdim return ret_plan_sp; 1144293116Semaste} 1145293116Semaste 1146293116SemasteFunctionCaller * 1147314564SdimAppleObjCTrampolineHandler::GetLookupImplementationFunctionCaller() { 1148314564Sdim return m_impl_code->GetFunctionCaller(); 1149293116Semaste} 1150