source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCTrampolineHandler.cpp

   1 //===-- AppleObjCTrampolineHandler.cpp ----------------------------*- C++
   2 //-*-===//
   3 //
   4 //                     The LLVM Compiler Infrastructure
   5 //
   6 // This file is distributed under the University of Illinois Open Source
   7 // License. See LICENSE.TXT for details.
   8 //
   9 //===----------------------------------------------------------------------===//
  10
  11 #include "AppleObjCTrampolineHandler.h"
  12
  13 // C Includes
  14 // C++ Includes
  15 // Other libraries and framework includes
  16 // Project includes
  17 #include "AppleThreadPlanStepThroughObjCTrampoline.h"
  18
  19 #include "lldb/Breakpoint/StoppointCallbackContext.h"
  20 #include "lldb/Core/ConstString.h"
  21 #include "lldb/Core/Debugger.h"
  22 #include "lldb/Core/Log.h"
  23 #include "lldb/Core/Module.h"
  24 #include "lldb/Core/StreamFile.h"
  25 #include "lldb/Core/Value.h"
  26 #include "lldb/Expression/DiagnosticManager.h"
  27 #include "lldb/Expression/FunctionCaller.h"
  28 #include "lldb/Expression/UserExpression.h"
  29 #include "lldb/Expression/UtilityFunction.h"
  30 #include "lldb/Host/FileSpec.h"
  31 #include "lldb/Symbol/ClangASTContext.h"
  32 #include "lldb/Symbol/Symbol.h"
  33 #include "lldb/Target/ABI.h"
  34 #include "lldb/Target/ExecutionContext.h"
  35 #include "lldb/Target/ObjCLanguageRuntime.h"
  36 #include "lldb/Target/Process.h"
  37 #include "lldb/Target/RegisterContext.h"
  38 #include "lldb/Target/Target.h"
  39 #include "lldb/Target/Thread.h"
  40 #include "lldb/Target/ThreadPlanRunToAddress.h"
  41
  42 #include "llvm/ADT/STLExtras.h"
  43
  44 using namespace lldb;
  45 using namespace lldb_private;
  46
  47 const char *AppleObjCTrampolineHandler::g_lookup_implementation_function_name =
  48     "__lldb_objc_find_implementation_for_selector";
  49 const char *AppleObjCTrampolineHandler::
  50     g_lookup_implementation_with_stret_function_code =
  51         "                               \n\
  52 extern \"C\"                                                                                                    \n\
  53 {                                                                                                               \n\
  54     extern void *class_getMethodImplementation(void *objc_class, void *sel);                                    \n\
  55     extern void *class_getMethodImplementation_stret(void *objc_class, void *sel);                              \n\
  56     extern void * object_getClass (id object);                                                                  \n\
  57     extern void * sel_getUid(char *name);                                                                       \n\
  58     extern int printf(const char *format, ...);                                                                 \n\
  59 }                                                                                                               \n\
  60 extern \"C\" void * __lldb_objc_find_implementation_for_selector (void *object,                                 \n\
  61                                                     void *sel,                                                  \n\
  62                                                     int is_stret,                                               \n\
  63                                                     int is_super,                                               \n\
  64                                                     int is_super2,                                              \n\
  65                                                     int is_fixup,                                               \n\
  66                                                     int is_fixed,                                               \n\
  67                                                     int debug)                                                  \n\
  68 {                                                                                                               \n\
  69     struct __lldb_imp_return_struct                                                                             \n\
  70     {                                                                                                           \n\
  71         void *class_addr;                                                                                       \n\
  72         void *sel_addr;                                                                                         \n\
  73         void *impl_addr;                                                                                        \n\
  74     };                                                                                                          \n\
  75                                                                                                                 \n\
  76     struct __lldb_objc_class {                                                                                  \n\
  77         void *isa;                                                                                              \n\
  78         void *super_ptr;                                                                                        \n\
  79     };                                                                                                          \n\
  80     struct __lldb_objc_super {                                                                                  \n\
  81         void *reciever;                                                                                         \n\
  82         struct __lldb_objc_class *class_ptr;                                                                    \n\
  83     };                                                                                                          \n\
  84     struct __lldb_msg_ref {                                                                                     \n\
  85         void *dont_know;                                                                                        \n\
  86         void *sel;                                                                                              \n\
  87     };                                                                                                          \n\
  88                                                                                                                 \n\
  89     struct __lldb_imp_return_struct return_struct;                                                              \n\
  90                                                                                                                 \n\
  91     if (debug)                                                                                                  \n\
  92         printf (\"\\n*** Called with obj: 0x%p sel: 0x%p is_stret: %d is_super: %d, \"                          \n\
  93                 \"is_super2: %d, is_fixup: %d, is_fixed: %d\\n\",                                               \n\
  94                  object, sel, is_stret, is_super, is_super2, is_fixup, is_fixed);                               \n\
  95     if (is_super)                                                                                               \n\
  96     {                                                                                                           \n\
  97         if (is_super2)                                                                                          \n\
  98         {                                                                                                       \n\
  99             return_struct.class_addr = ((__lldb_objc_super *) object)->class_ptr->super_ptr;                    \n\
 100         }                                                                                                       \n\
 101         else                                                                                                    \n\
 102         {                                                                                                       \n\
 103             return_struct.class_addr = ((__lldb_objc_super *) object)->class_ptr;                               \n\
 104         }                                                                                                       \n\
 105     }                                                                                                           \n\
 106     else                                                                                                        \n\
 107     {                                                                                                           \n\
 108         // This code seems a little funny, but has its reasons...                                               \n\
 109         // The call to [object class] is here because if this is a class, and has not been called into          \n\
 110         // yet, we need to do something to force the class to initialize itself.                                \n\
 111         // Then the call to object_getClass will actually return the correct class, either the class            \n\
 112         // if object is a class instance, or the meta-class if it is a class pointer.                           \n\
 113         void *class_ptr = (void *) [(id) object class];                                                         \n\
 114         return_struct.class_addr = (id)  object_getClass((id) object);                                          \n\
 115         if (debug)                                                                                              \n\
 116         {                                                                                                       \n\
 117             if (class_ptr == object)                                                                            \n\
 118             {                                                                                                   \n\
 119                 printf (\"Found a class object, need to use the meta class %p -> %p\\n\",                       \n\
 120                         class_ptr, return_struct.class_addr);                                                   \n\
 121             }                                                                                                   \n\
 122             else                                                                                                \n\
 123             {                                                                                                   \n\
 124                  printf (\"[object class] returned: %p object_getClass: %p.\\n\",                               \n\
 125                  class_ptr, return_struct.class_addr);                                                          \n\
 126             }                                                                                                   \n\
 127         }                                                                                                       \n\
 128     }                                                                                                           \n\
 129                                                                                                                 \n\
 130     if (is_fixup)                                                                                               \n\
 131     {                                                                                                           \n\
 132         if (is_fixed)                                                                                           \n\
 133         {                                                                                                       \n\
 134             return_struct.sel_addr = ((__lldb_msg_ref *) sel)->sel;                                             \n\
 135         }                                                                                                       \n\
 136         else                                                                                                    \n\
 137         {                                                                                                       \n\
 138             char *sel_name = (char *) ((__lldb_msg_ref *) sel)->sel;                                            \n\
 139             return_struct.sel_addr = sel_getUid (sel_name);                                                     \n\
 140             if (debug)                                                                                          \n\
 141                 printf (\"\\n*** Got fixed up selector: %p for name %s.\\n\",                                   \n\
 142                         return_struct.sel_addr, sel_name);                                                      \n\
 143         }                                                                                                       \n\
 144     }                                                                                                           \n\
 145     else                                                                                                        \n\
 146     {                                                                                                           \n\
 147         return_struct.sel_addr = sel;                                                                           \n\
 148     }                                                                                                           \n\
 149                                                                                                                 \n\
 150     if (is_stret)                                                                                               \n\
 151     {                                                                                                           \n\
 152         return_struct.impl_addr = class_getMethodImplementation_stret (return_struct.class_addr,                \n\
 153                                                                        return_struct.sel_addr);                 \n\
 154     }                                                                                                           \n\
 155     else                                                                                                        \n\
 156     {                                                                                                           \n\
 157         return_struct.impl_addr = class_getMethodImplementation (return_struct.class_addr,                      \n\
 158                                                                        return_struct.sel_addr);                 \n\
 159     }                                                                                                           \n\
 160     if (debug)                                                                                                  \n\
 161         printf (\"\\n*** Returning implementation: %p.\\n\", return_struct.impl_addr);                          \n\
 162                                                                                                                 \n\
 163     return return_struct.impl_addr;                                                                             \n\
 164 }                                                                                                               \n\
 165 ";
 166 const char *
 167     AppleObjCTrampolineHandler::g_lookup_implementation_no_stret_function_code =
 168         "                      \n\
 169 extern \"C\"                                                                                                    \n\
 170 {                                                                                                               \n\
 171     extern void *class_getMethodImplementation(void *objc_class, void *sel);                                    \n\
 172     extern void * object_getClass (id object);                                                                  \n\
 173     extern void * sel_getUid(char *name);                                                                       \n\
 174     extern int printf(const char *format, ...);                                                                 \n\
 175 }                                                                                                               \n\
 176 extern \"C\" void * __lldb_objc_find_implementation_for_selector (void *object,                                 \n\
 177                                                     void *sel,                                                  \n\
 178                                                     int is_stret,                                               \n\
 179                                                     int is_super,                                               \n\
 180                                                     int is_super2,                                              \n\
 181                                                     int is_fixup,                                               \n\
 182                                                     int is_fixed,                                               \n\
 183                                                     int debug)                                                  \n\
 184 {                                                                                                               \n\
 185     struct __lldb_imp_return_struct                                                                             \n\
 186     {                                                                                                           \n\
 187         void *class_addr;                                                                                       \n\
 188         void *sel_addr;                                                                                         \n\
 189         void *impl_addr;                                                                                        \n\
 190     };                                                                                                          \n\
 191                                                                                                                 \n\
 192     struct __lldb_objc_class {                                                                                  \n\
 193         void *isa;                                                                                              \n\
 194         void *super_ptr;                                                                                        \n\
 195     };                                                                                                          \n\
 196     struct __lldb_objc_super {                                                                                  \n\
 197         void *reciever;                                                                                         \n\
 198         struct __lldb_objc_class *class_ptr;                                                                    \n\
 199     };                                                                                                          \n\
 200     struct __lldb_msg_ref {                                                                                     \n\
 201         void *dont_know;                                                                                        \n\
 202         void *sel;                                                                                              \n\
 203     };                                                                                                          \n\
 204                                                                                                                 \n\
 205     struct __lldb_imp_return_struct return_struct;                                                              \n\
 206                                                                                                                 \n\
 207     if (debug)                                                                                                  \n\
 208         printf (\"\\n*** Called with obj: 0x%p sel: 0x%p is_stret: %d is_super: %d, \"                          \n\
 209                 \"is_super2: %d, is_fixup: %d, is_fixed: %d\\n\",                                               \n\
 210                  object, sel, is_stret, is_super, is_super2, is_fixup, is_fixed);                               \n\
 211     if (is_super)                                                                                               \n\
 212     {                                                                                                           \n\
 213         if (is_super2)                                                                                          \n\
 214         {                                                                                                       \n\
 215             return_struct.class_addr = ((__lldb_objc_super *) object)->class_ptr->super_ptr;                    \n\
 216         }                                                                                                       \n\
 217         else                                                                                                    \n\
 218         {                                                                                                       \n\
 219             return_struct.class_addr = ((__lldb_objc_super *) object)->class_ptr;                               \n\
 220         }                                                                                                       \n\
 221     }                                                                                                           \n\
 222     else                                                                                                        \n\
 223     {                                                                                                           \n\
 224         // This code seems a little funny, but has its reasons...                                               \n\
 225         // The call to [object class] is here because if this is a class, and has not been called into          \n\
 226         // yet, we need to do something to force the class to initialize itself.                                \n\
 227         // Then the call to object_getClass will actually return the correct class, either the class            \n\
 228         // if object is a class instance, or the meta-class if it is a class pointer.                           \n\
 229         void *class_ptr = (void *) [(id) object class];                                                         \n\
 230         return_struct.class_addr = (id)  object_getClass((id) object);                                          \n\
 231         if (debug)                                                                                              \n\
 232         {                                                                                                       \n\
 233             if (class_ptr == object)                                                                            \n\
 234             {                                                                                                   \n\
 235                 printf (\"Found a class object, need to return the meta class %p -> %p\\n\",                    \n\
 236                         class_ptr, return_struct.class_addr);                                                   \n\
 237             }                                                                                                   \n\
 238             else                                                                                                \n\
 239             {                                                                                                   \n\
 240                  printf (\"[object class] returned: %p object_getClass: %p.\\n\",                               \n\
 241                  class_ptr, return_struct.class_addr);                                                          \n\
 242             }                                                                                                   \n\
 243         }                                                                                                       \n\
 244     }                                                                                                           \n\
 245                                                                                                                 \n\
 246     if (is_fixup)                                                                                               \n\
 247     {                                                                                                           \n\
 248         if (is_fixed)                                                                                           \n\
 249         {                                                                                                       \n\
 250             return_struct.sel_addr = ((__lldb_msg_ref *) sel)->sel;                                             \n\
 251         }                                                                                                       \n\
 252         else                                                                                                    \n\
 253         {                                                                                                       \n\
 254             char *sel_name = (char *) ((__lldb_msg_ref *) sel)->sel;                                            \n\
 255             return_struct.sel_addr = sel_getUid (sel_name);                                                     \n\
 256             if (debug)                                                                                          \n\
 257                 printf (\"\\n*** Got fixed up selector: %p for name %s.\\n\",                                   \n\
 258                         return_struct.sel_addr, sel_name);                                                      \n\
 259         }                                                                                                       \n\
 260     }                                                                                                           \n\
 261     else                                                                                                        \n\
 262     {                                                                                                           \n\
 263         return_struct.sel_addr = sel;                                                                           \n\
 264     }                                                                                                           \n\
 265                                                                                                                 \n\
 266     return_struct.impl_addr = class_getMethodImplementation (return_struct.class_addr,                          \n\
 267                                                              return_struct.sel_addr);                           \n\
 268     if (debug)                                                                                                  \n\
 269         printf (\"\\n*** Returning implementation: 0x%p.\\n\", return_struct.impl_addr);                        \n\
 270                                                                                                                 \n\
 271     return return_struct.impl_addr;                                                                             \n\
 272 }                                                                                                               \n\
 273 ";
 274
 275 AppleObjCTrampolineHandler::AppleObjCVTables::VTableRegion::VTableRegion(
 276     AppleObjCVTables *owner, lldb::addr_t header_addr)
 277     : m_valid(true), m_owner(owner), m_header_addr(header_addr),
 278       m_code_start_addr(0), m_code_end_addr(0), m_next_region(0) {
 279   SetUpRegion();
 280 }
 281
 282 AppleObjCTrampolineHandler::~AppleObjCTrampolineHandler() {}
 283
 284 void AppleObjCTrampolineHandler::AppleObjCVTables::VTableRegion::SetUpRegion() {
 285   // The header looks like:
 286   //
 287   //   uint16_t headerSize
 288   //   uint16_t descSize
 289   //   uint32_t descCount
 290   //   void * next
 291   //
 292   // First read in the header:
 293
 294   char memory_buffer[16];
 295   ProcessSP process_sp = m_owner->GetProcessSP();
 296   if (!process_sp)
 297     return;
 298   DataExtractor data(memory_buffer, sizeof(memory_buffer),
 299                      process_sp->GetByteOrder(),
 300                      process_sp->GetAddressByteSize());
 301   size_t actual_size = 8 + process_sp->GetAddressByteSize();
 302   Error error;
 303   size_t bytes_read =
 304       process_sp->ReadMemory(m_header_addr, memory_buffer, actual_size, error);
 305   if (bytes_read != actual_size) {
 306     m_valid = false;
 307     return;
 308   }
 309
 310   lldb::offset_t offset = 0;
 311   const uint16_t header_size = data.GetU16(&offset);
 312   const uint16_t descriptor_size = data.GetU16(&offset);
 313   const size_t num_descriptors = data.GetU32(&offset);
 314
 315   m_next_region = data.GetPointer(&offset);
 316
 317   // If the header size is 0, that means we've come in too early before this
 318   // data is set up.
 319   // Set ourselves as not valid, and continue.
 320   if (header_size == 0 || num_descriptors == 0) {
 321     m_valid = false;
 322     return;
 323   }
 324
 325   // Now read in all the descriptors:
 326   // The descriptor looks like:
 327   //
 328   // uint32_t offset
 329   // uint32_t flags
 330   //
 331   // Where offset is either 0 - in which case it is unused, or
 332   // it is the offset of the vtable code from the beginning of the descriptor
 333   // record.
 334   // Below, we'll convert that into an absolute code address, since I don't want
 335   // to have
 336   // to compute it over and over.
 337
 338   // Ingest the whole descriptor array:
 339   const lldb::addr_t desc_ptr = m_header_addr + header_size;
 340   const size_t desc_array_size = num_descriptors * descriptor_size;
 341   DataBufferSP data_sp(new DataBufferHeap(desc_array_size, '\0'));
 342   uint8_t *dst = (uint8_t *)data_sp->GetBytes();
 343
 344   DataExtractor desc_extractor(dst, desc_array_size, process_sp->GetByteOrder(),
 345                                process_sp->GetAddressByteSize());
 346   bytes_read = process_sp->ReadMemory(desc_ptr, dst, desc_array_size, error);
 347   if (bytes_read != desc_array_size) {
 348     m_valid = false;
 349     return;
 350   }
 351
 352   // The actual code for the vtables will be laid out consecutively, so I also
 353   // compute the start and end of the whole code block.
 354
 355   offset = 0;
 356   m_code_start_addr = 0;
 357   m_code_end_addr = 0;
 358
 359   for (size_t i = 0; i < num_descriptors; i++) {
 360     lldb::addr_t start_offset = offset;
 361     uint32_t voffset = desc_extractor.GetU32(&offset);
 362     uint32_t flags = desc_extractor.GetU32(&offset);
 363     lldb::addr_t code_addr = desc_ptr + start_offset + voffset;
 364     m_descriptors.push_back(VTableDescriptor(flags, code_addr));
 365
 366     if (m_code_start_addr == 0 || code_addr < m_code_start_addr)
 367       m_code_start_addr = code_addr;
 368     if (code_addr > m_code_end_addr)
 369       m_code_end_addr = code_addr;
 370
 371     offset = start_offset + descriptor_size;
 372   }
 373   // Finally, a little bird told me that all the vtable code blocks are the same
 374   // size.
 375   // Let's compute the blocks and if they are all the same add the size to the
 376   // code end address:
 377   lldb::addr_t code_size = 0;
 378   bool all_the_same = true;
 379   for (size_t i = 0; i < num_descriptors - 1; i++) {
 380     lldb::addr_t this_size =
 381         m_descriptors[i + 1].code_start - m_descriptors[i].code_start;
 382     if (code_size == 0)
 383       code_size = this_size;
 384     else {
 385       if (this_size != code_size)
 386         all_the_same = false;
 387       if (this_size > code_size)
 388         code_size = this_size;
 389     }
 390   }
 391   if (all_the_same)
 392     m_code_end_addr += code_size;
 393 }
 394
 395 bool AppleObjCTrampolineHandler::AppleObjCVTables::VTableRegion::
 396     AddressInRegion(lldb::addr_t addr, uint32_t &flags) {
 397   if (!IsValid())
 398     return false;
 399
 400   if (addr < m_code_start_addr || addr > m_code_end_addr)
 401     return false;
 402
 403   std::vector<VTableDescriptor>::iterator pos, end = m_descriptors.end();
 404   for (pos = m_descriptors.begin(); pos != end; pos++) {
 405     if (addr <= (*pos).code_start) {
 406       flags = (*pos).flags;
 407       return true;
 408     }
 409   }
 410   return false;
 411 }
 412
 413 void AppleObjCTrampolineHandler::AppleObjCVTables::VTableRegion::Dump(
 414     Stream &s) {
 415   s.Printf("Header addr: 0x%" PRIx64 " Code start: 0x%" PRIx64
 416            " Code End: 0x%" PRIx64 " Next: 0x%" PRIx64 "\n",
 417            m_header_addr, m_code_start_addr, m_code_end_addr, m_next_region);
 418   size_t num_elements = m_descriptors.size();
 419   for (size_t i = 0; i < num_elements; i++) {
 420     s.Indent();
 421     s.Printf("Code start: 0x%" PRIx64 " Flags: %d\n",
 422              m_descriptors[i].code_start, m_descriptors[i].flags);
 423   }
 424 }
 425
 426 AppleObjCTrampolineHandler::AppleObjCVTables::AppleObjCVTables(
 427     const ProcessSP &process_sp, const ModuleSP &objc_module_sp)
 428     : m_process_wp(), m_trampoline_header(LLDB_INVALID_ADDRESS),
 429       m_trampolines_changed_bp_id(LLDB_INVALID_BREAK_ID),
 430       m_objc_module_sp(objc_module_sp) {
 431   if (process_sp)
 432     m_process_wp = process_sp;
 433 }
 434
 435 AppleObjCTrampolineHandler::AppleObjCVTables::~AppleObjCVTables() {
 436   ProcessSP process_sp = GetProcessSP();
 437   if (process_sp) {
 438     if (m_trampolines_changed_bp_id != LLDB_INVALID_BREAK_ID)
 439       process_sp->GetTarget().RemoveBreakpointByID(m_trampolines_changed_bp_id);
 440   }
 441 }
 442
 443 bool AppleObjCTrampolineHandler::AppleObjCVTables::InitializeVTableSymbols() {
 444   if (m_trampoline_header != LLDB_INVALID_ADDRESS)
 445     return true;
 446
 447   ProcessSP process_sp = GetProcessSP();
 448   if (process_sp) {
 449     Target &target = process_sp->GetTarget();
 450
 451     const ModuleList &target_modules = target.GetImages();
 452     std::lock_guard<std::recursive_mutex> guard(target_modules.GetMutex());
 453     size_t num_modules = target_modules.GetSize();
 454     if (!m_objc_module_sp) {
 455       for (size_t i = 0; i < num_modules; i++) {
 456         if (process_sp->GetObjCLanguageRuntime()->IsModuleObjCLibrary(
 457                 target_modules.GetModuleAtIndexUnlocked(i))) {
 458           m_objc_module_sp = target_modules.GetModuleAtIndexUnlocked(i);
 459           break;
 460         }
 461       }
 462     }
 463
 464     if (m_objc_module_sp) {
 465       ConstString trampoline_name("gdb_objc_trampolines");
 466       const Symbol *trampoline_symbol =
 467           m_objc_module_sp->FindFirstSymbolWithNameAndType(trampoline_name,
 468                                                            eSymbolTypeData);
 469       if (trampoline_symbol != NULL) {
 470         m_trampoline_header = trampoline_symbol->GetLoadAddress(&target);
 471         if (m_trampoline_header == LLDB_INVALID_ADDRESS)
 472           return false;
 473
 474         // Next look up the "changed" symbol and set a breakpoint on that...
 475         ConstString changed_name("gdb_objc_trampolines_changed");
 476         const Symbol *changed_symbol =
 477             m_objc_module_sp->FindFirstSymbolWithNameAndType(changed_name,
 478                                                              eSymbolTypeCode);
 479         if (changed_symbol != NULL) {
 480           const Address changed_symbol_addr = changed_symbol->GetAddress();
 481           if (!changed_symbol_addr.IsValid())
 482             return false;
 483
 484           lldb::addr_t changed_addr =
 485               changed_symbol_addr.GetOpcodeLoadAddress(&target);
 486           if (changed_addr != LLDB_INVALID_ADDRESS) {
 487             BreakpointSP trampolines_changed_bp_sp =
 488                 target.CreateBreakpoint(changed_addr, true, false);
 489             if (trampolines_changed_bp_sp) {
 490               m_trampolines_changed_bp_id = trampolines_changed_bp_sp->GetID();
 491               trampolines_changed_bp_sp->SetCallback(RefreshTrampolines, this,
 492                                                      true);
 493               trampolines_changed_bp_sp->SetBreakpointKind(
 494                   "objc-trampolines-changed");
 495               return true;
 496             }
 497           }
 498         }
 499       }
 500     }
 501   }
 502   return false;
 503 }
 504
 505 bool AppleObjCTrampolineHandler::AppleObjCVTables::RefreshTrampolines(
 506     void *baton, StoppointCallbackContext *context, lldb::user_id_t break_id,
 507     lldb::user_id_t break_loc_id) {
 508   AppleObjCVTables *vtable_handler = (AppleObjCVTables *)baton;
 509   if (vtable_handler->InitializeVTableSymbols()) {
 510     // The Update function is called with the address of an added region.  So we
 511     // grab that address, and
 512     // feed it into ReadRegions.  Of course, our friend the ABI will get the
 513     // values for us.
 514     ExecutionContext exe_ctx(context->exe_ctx_ref);
 515     Process *process = exe_ctx.GetProcessPtr();
 516     const ABI *abi = process->GetABI().get();
 517
 518     ClangASTContext *clang_ast_context =
 519         process->GetTarget().GetScratchClangASTContext();
 520     ValueList argument_values;
 521     Value input_value;
 522     CompilerType clang_void_ptr_type =
 523         clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType();
 524
 525     input_value.SetValueType(Value::eValueTypeScalar);
 526     // input_value.SetContext (Value::eContextTypeClangType,
 527     // clang_void_ptr_type);
 528     input_value.SetCompilerType(clang_void_ptr_type);
 529     argument_values.PushValue(input_value);
 530
 531     bool success =
 532         abi->GetArgumentValues(exe_ctx.GetThreadRef(), argument_values);
 533     if (!success)
 534       return false;
 535
 536     // Now get a pointer value from the zeroth argument.
 537     Error error;
 538     DataExtractor data;
 539     error = argument_values.GetValueAtIndex(0)->GetValueAsData(&exe_ctx, data,
 540                                                                0, NULL);
 541     lldb::offset_t offset = 0;
 542     lldb::addr_t region_addr = data.GetPointer(&offset);
 543
 544     if (region_addr != 0)
 545       vtable_handler->ReadRegions(region_addr);
 546   }
 547   return false;
 548 }
 549
 550 bool AppleObjCTrampolineHandler::AppleObjCVTables::ReadRegions() {
 551   // The no argument version reads the start region from the value of the
 552   // gdb_regions_header, and
 553   // gets started from there.
 554
 555   m_regions.clear();
 556   if (!InitializeVTableSymbols())
 557     return false;
 558   Error error;
 559   ProcessSP process_sp = GetProcessSP();
 560   if (process_sp) {
 561     lldb::addr_t region_addr =
 562         process_sp->ReadPointerFromMemory(m_trampoline_header, error);
 563     if (error.Success())
 564       return ReadRegions(region_addr);
 565   }
 566   return false;
 567 }
 568
 569 bool AppleObjCTrampolineHandler::AppleObjCVTables::ReadRegions(
 570     lldb::addr_t region_addr) {
 571   ProcessSP process_sp = GetProcessSP();
 572   if (!process_sp)
 573     return false;
 574
 575   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
 576
 577   // We aren't starting at the trampoline symbol.
 578   InitializeVTableSymbols();
 579   lldb::addr_t next_region = region_addr;
 580
 581   // Read in the sizes of the headers.
 582   while (next_region != 0) {
 583     m_regions.push_back(VTableRegion(this, next_region));
 584     if (!m_regions.back().IsValid()) {
 585       m_regions.clear();
 586       return false;
 587     }
 588     if (log) {
 589       StreamString s;
 590       m_regions.back().Dump(s);
 591       log->Printf("Read vtable region: \n%s", s.GetData());
 592     }
 593
 594     next_region = m_regions.back().GetNextRegionAddr();
 595   }
 596
 597   return true;
 598 }
 599
 600 bool AppleObjCTrampolineHandler::AppleObjCVTables::IsAddressInVTables(
 601     lldb::addr_t addr, uint32_t &flags) {
 602   region_collection::iterator pos, end = m_regions.end();
 603   for (pos = m_regions.begin(); pos != end; pos++) {
 604     if ((*pos).AddressInRegion(addr, flags))
 605       return true;
 606   }
 607   return false;
 608 }
 609
 610 const AppleObjCTrampolineHandler::DispatchFunction
 611     AppleObjCTrampolineHandler::g_dispatch_functions[] = {
 612         // NAME                              STRET  SUPER  SUPER2  FIXUP TYPE
 613         {"objc_msgSend", false, false, false, DispatchFunction::eFixUpNone},
 614         {"objc_msgSend_fixup", false, false, false,
 615          DispatchFunction::eFixUpToFix},
 616         {"objc_msgSend_fixedup", false, false, false,
 617          DispatchFunction::eFixUpFixed},
 618         {"objc_msgSend_stret", true, false, false,
 619          DispatchFunction::eFixUpNone},
 620         {"objc_msgSend_stret_fixup", true, false, false,
 621          DispatchFunction::eFixUpToFix},
 622         {"objc_msgSend_stret_fixedup", true, false, false,
 623          DispatchFunction::eFixUpFixed},
 624         {"objc_msgSend_fpret", false, false, false,
 625          DispatchFunction::eFixUpNone},
 626         {"objc_msgSend_fpret_fixup", false, false, false,
 627          DispatchFunction::eFixUpToFix},
 628         {"objc_msgSend_fpret_fixedup", false, false, false,
 629          DispatchFunction::eFixUpFixed},
 630         {"objc_msgSend_fp2ret", false, false, true,
 631          DispatchFunction::eFixUpNone},
 632         {"objc_msgSend_fp2ret_fixup", false, false, true,
 633          DispatchFunction::eFixUpToFix},
 634         {"objc_msgSend_fp2ret_fixedup", false, false, true,
 635          DispatchFunction::eFixUpFixed},
 636         {"objc_msgSendSuper", false, true, false, DispatchFunction::eFixUpNone},
 637         {"objc_msgSendSuper_stret", true, true, false,
 638          DispatchFunction::eFixUpNone},
 639         {"objc_msgSendSuper2", false, true, true, DispatchFunction::eFixUpNone},
 640         {"objc_msgSendSuper2_fixup", false, true, true,
 641          DispatchFunction::eFixUpToFix},
 642         {"objc_msgSendSuper2_fixedup", false, true, true,
 643          DispatchFunction::eFixUpFixed},
 644         {"objc_msgSendSuper2_stret", true, true, true,
 645          DispatchFunction::eFixUpNone},
 646         {"objc_msgSendSuper2_stret_fixup", true, true, true,
 647          DispatchFunction::eFixUpToFix},
 648         {"objc_msgSendSuper2_stret_fixedup", true, true, true,
 649          DispatchFunction::eFixUpFixed},
 650 };
 651
 652 AppleObjCTrampolineHandler::AppleObjCTrampolineHandler(
 653     const ProcessSP &process_sp, const ModuleSP &objc_module_sp)
 654     : m_process_wp(), m_objc_module_sp(objc_module_sp),
 655       m_lookup_implementation_function_code(nullptr),
 656       m_impl_fn_addr(LLDB_INVALID_ADDRESS),
 657       m_impl_stret_fn_addr(LLDB_INVALID_ADDRESS),
 658       m_msg_forward_addr(LLDB_INVALID_ADDRESS) {
 659   if (process_sp)
 660     m_process_wp = process_sp;
 661   // Look up the known resolution functions:
 662
 663   ConstString get_impl_name("class_getMethodImplementation");
 664   ConstString get_impl_stret_name("class_getMethodImplementation_stret");
 665   ConstString msg_forward_name("_objc_msgForward");
 666   ConstString msg_forward_stret_name("_objc_msgForward_stret");
 667
 668   Target *target = process_sp ? &process_sp->GetTarget() : NULL;
 669   const Symbol *class_getMethodImplementation =
 670       m_objc_module_sp->FindFirstSymbolWithNameAndType(get_impl_name,
 671                                                        eSymbolTypeCode);
 672   const Symbol *class_getMethodImplementation_stret =
 673       m_objc_module_sp->FindFirstSymbolWithNameAndType(get_impl_stret_name,
 674                                                        eSymbolTypeCode);
 675   const Symbol *msg_forward = m_objc_module_sp->FindFirstSymbolWithNameAndType(
 676       msg_forward_name, eSymbolTypeCode);
 677   const Symbol *msg_forward_stret =
 678       m_objc_module_sp->FindFirstSymbolWithNameAndType(msg_forward_stret_name,
 679                                                        eSymbolTypeCode);
 680
 681   if (class_getMethodImplementation)
 682     m_impl_fn_addr =
 683         class_getMethodImplementation->GetAddress().GetOpcodeLoadAddress(
 684             target);
 685   if (class_getMethodImplementation_stret)
 686     m_impl_stret_fn_addr =
 687         class_getMethodImplementation_stret->GetAddress().GetOpcodeLoadAddress(
 688             target);
 689   if (msg_forward)
 690     m_msg_forward_addr = msg_forward->GetAddress().GetOpcodeLoadAddress(target);
 691   if (msg_forward_stret)
 692     m_msg_forward_stret_addr =
 693         msg_forward_stret->GetAddress().GetOpcodeLoadAddress(target);
 694
 695   // FIXME: Do some kind of logging here.
 696   if (m_impl_fn_addr == LLDB_INVALID_ADDRESS) {
 697     // If we can't even find the ordinary get method implementation function,
 698     // then we aren't going to be able to
 699     // step through any method dispatches.  Warn to that effect and get out of
 700     // here.
 701     if (process_sp->CanJIT()) {
 702       process_sp->GetTarget().GetDebugger().GetErrorFile()->Printf(
 703           "Could not find implementation lookup function \"%s\""
 704           " step in through ObjC method dispatch will not work.\n",
 705           get_impl_name.AsCString());
 706     }
 707     return;
 708   } else if (m_impl_stret_fn_addr == LLDB_INVALID_ADDRESS) {
 709     // It there is no stret return lookup function, assume that it is the same
 710     // as the straight lookup:
 711     m_impl_stret_fn_addr = m_impl_fn_addr;
 712     // Also we will use the version of the lookup code that doesn't rely on the
 713     // stret version of the function.
 714     m_lookup_implementation_function_code =
 715         g_lookup_implementation_no_stret_function_code;
 716   } else {
 717     m_lookup_implementation_function_code =
 718         g_lookup_implementation_with_stret_function_code;
 719   }
 720
 721   // Look up the addresses for the objc dispatch functions and cache them.  For
 722   // now I'm inspecting the symbol
 723   // names dynamically to figure out how to dispatch to them.  If it becomes
 724   // more complicated than this we can
 725   // turn the g_dispatch_functions char * array into a template table, and
 726   // populate the DispatchFunction map
 727   // from there.
 728
 729   for (size_t i = 0; i != llvm::array_lengthof(g_dispatch_functions); i++) {
 730     ConstString name_const_str(g_dispatch_functions[i].name);
 731     const Symbol *msgSend_symbol =
 732         m_objc_module_sp->FindFirstSymbolWithNameAndType(name_const_str,
 733                                                          eSymbolTypeCode);
 734     if (msgSend_symbol && msgSend_symbol->ValueIsAddress()) {
 735       // FixMe: Make g_dispatch_functions static table of DispatchFunctions, and
 736       // have the map be address->index.
 737       // Problem is we also need to lookup the dispatch function.  For now we
 738       // could have a side table of stret & non-stret
 739       // dispatch functions.  If that's as complex as it gets, we're fine.
 740
 741       lldb::addr_t sym_addr =
 742           msgSend_symbol->GetAddressRef().GetOpcodeLoadAddress(target);
 743
 744       m_msgSend_map.insert(std::pair<lldb::addr_t, int>(sym_addr, i));
 745     }
 746   }
 747
 748   // Build our vtable dispatch handler here:
 749   m_vtables_ap.reset(new AppleObjCVTables(process_sp, m_objc_module_sp));
 750   if (m_vtables_ap.get())
 751     m_vtables_ap->ReadRegions();
 752 }
 753
 754 lldb::addr_t
 755 AppleObjCTrampolineHandler::SetupDispatchFunction(Thread &thread,
 756                                                   ValueList &dispatch_values) {
 757   ThreadSP thread_sp(thread.shared_from_this());
 758   ExecutionContext exe_ctx(thread_sp);
 759   DiagnosticManager diagnostics;
 760   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
 761
 762   lldb::addr_t args_addr = LLDB_INVALID_ADDRESS;
 763   FunctionCaller *impl_function_caller = nullptr;
 764
 765   // Scope for mutex locker:
 766   {
 767     std::lock_guard<std::mutex> guard(m_impl_function_mutex);
 768
 769     // First stage is to make the ClangUtility to hold our injected function:
 770
 771     if (!m_impl_code.get()) {
 772       if (m_lookup_implementation_function_code != NULL) {
 773         Error error;
 774         m_impl_code.reset(exe_ctx.GetTargetRef().GetUtilityFunctionForLanguage(
 775             m_lookup_implementation_function_code, eLanguageTypeObjC,
 776             g_lookup_implementation_function_name, error));
 777         if (error.Fail()) {
 778           if (log)
 779             log->Printf(
 780                 "Failed to get Utility Function for implementation lookup: %s.",
 781                 error.AsCString());
 782           m_impl_code.reset();
 783           return args_addr;
 784         }
 785
 786         if (!m_impl_code->Install(diagnostics, exe_ctx)) {
 787           if (log) {
 788             log->Printf("Failed to install implementation lookup.");
 789             diagnostics.Dump(log);
 790           }
 791           m_impl_code.reset();
 792           return args_addr;
 793         }
 794       } else {
 795         if (log)
 796           log->Printf("No method lookup implementation code.");
 797         return LLDB_INVALID_ADDRESS;
 798       }
 799
 800       // Next make the runner function for our implementation utility function.
 801       ClangASTContext *clang_ast_context =
 802           thread.GetProcess()->GetTarget().GetScratchClangASTContext();
 803       CompilerType clang_void_ptr_type =
 804           clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType();
 805       Error error;
 806
 807       impl_function_caller = m_impl_code->MakeFunctionCaller(
 808           clang_void_ptr_type, dispatch_values, thread_sp, error);
 809       if (error.Fail()) {
 810         if (log)
 811           log->Printf(
 812               "Error getting function caller for dispatch lookup: \"%s\".",
 813               error.AsCString());
 814         return args_addr;
 815       }
 816     } else {
 817       impl_function_caller = m_impl_code->GetFunctionCaller();
 818     }
 819   }
 820
 821   diagnostics.Clear();
 822
 823   // Now write down the argument values for this particular call.  This looks
 824   // like it might be a race condition
 825   // if other threads were calling into here, but actually it isn't because we
 826   // allocate a new args structure for
 827   // this call by passing args_addr = LLDB_INVALID_ADDRESS...
 828
 829   if (!impl_function_caller->WriteFunctionArguments(
 830           exe_ctx, args_addr, dispatch_values, diagnostics)) {
 831     if (log) {
 832       log->Printf("Error writing function arguments.");
 833       diagnostics.Dump(log);
 834     }
 835     return args_addr;
 836   }
 837
 838   return args_addr;
 839 }
 840
 841 ThreadPlanSP
 842 AppleObjCTrampolineHandler::GetStepThroughDispatchPlan(Thread &thread,
 843                                                        bool stop_others) {
 844   ThreadPlanSP ret_plan_sp;
 845   lldb::addr_t curr_pc = thread.GetRegisterContext()->GetPC();
 846
 847   DispatchFunction this_dispatch;
 848   bool found_it = false;
 849
 850   // First step is to look and see if we are in one of the known ObjC dispatch
 851   // functions.  We've already compiled
 852   // a table of same, so consult it.
 853
 854   MsgsendMap::iterator pos;
 855   pos = m_msgSend_map.find(curr_pc);
 856   if (pos != m_msgSend_map.end()) {
 857     this_dispatch = g_dispatch_functions[(*pos).second];
 858     found_it = true;
 859   }
 860
 861   // Next check to see if we are in a vtable region:
 862
 863   if (!found_it) {
 864     uint32_t flags;
 865     if (m_vtables_ap.get()) {
 866       found_it = m_vtables_ap->IsAddressInVTables(curr_pc, flags);
 867       if (found_it) {
 868         this_dispatch.name = "vtable";
 869         this_dispatch.stret_return =
 870             (flags & AppleObjCVTables::eOBJC_TRAMPOLINE_STRET) ==
 871             AppleObjCVTables::eOBJC_TRAMPOLINE_STRET;
 872         this_dispatch.is_super = false;
 873         this_dispatch.is_super2 = false;
 874         this_dispatch.fixedup = DispatchFunction::eFixUpFixed;
 875       }
 876     }
 877   }
 878
 879   if (found_it) {
 880     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
 881
 882     // We are decoding a method dispatch.
 883     // First job is to pull the arguments out:
 884
 885     lldb::StackFrameSP thread_cur_frame = thread.GetStackFrameAtIndex(0);
 886
 887     const ABI *abi = NULL;
 888     ProcessSP process_sp(thread.CalculateProcess());
 889     if (process_sp)
 890       abi = process_sp->GetABI().get();
 891     if (abi == NULL)
 892       return ret_plan_sp;
 893
 894     TargetSP target_sp(thread.CalculateTarget());
 895
 896     ClangASTContext *clang_ast_context = target_sp->GetScratchClangASTContext();
 897     ValueList argument_values;
 898     Value void_ptr_value;
 899     CompilerType clang_void_ptr_type =
 900         clang_ast_context->GetBasicType(eBasicTypeVoid).GetPointerType();
 901     void_ptr_value.SetValueType(Value::eValueTypeScalar);
 902     // void_ptr_value.SetContext (Value::eContextTypeClangType,
 903     // clang_void_ptr_type);
 904     void_ptr_value.SetCompilerType(clang_void_ptr_type);
 905
 906     int obj_index;
 907     int sel_index;
 908
 909     // If this is a struct return dispatch, then the first argument is the
 910     // return struct pointer, and the object is the second, and the selector is
 911     // the third.
 912     // Otherwise the object is the first and the selector the second.
 913     if (this_dispatch.stret_return) {
 914       obj_index = 1;
 915       sel_index = 2;
 916       argument_values.PushValue(void_ptr_value);
 917       argument_values.PushValue(void_ptr_value);
 918       argument_values.PushValue(void_ptr_value);
 919     } else {
 920       obj_index = 0;
 921       sel_index = 1;
 922       argument_values.PushValue(void_ptr_value);
 923       argument_values.PushValue(void_ptr_value);
 924     }
 925
 926     bool success = abi->GetArgumentValues(thread, argument_values);
 927     if (!success)
 928       return ret_plan_sp;
 929
 930     lldb::addr_t obj_addr =
 931         argument_values.GetValueAtIndex(obj_index)->GetScalar().ULongLong();
 932     if (obj_addr == 0x0) {
 933       if (log)
 934         log->Printf(
 935             "Asked to step to dispatch to nil object, returning empty plan.");
 936       return ret_plan_sp;
 937     }
 938
 939     ExecutionContext exe_ctx(thread.shared_from_this());
 940     Process *process = exe_ctx.GetProcessPtr();
 941     // isa_addr will store the class pointer that the method is being dispatched
 942     // to - so either the class
 943     // directly or the super class if this is one of the objc_msgSendSuper
 944     // flavors.  That's mostly used to
 945     // look up the class/selector pair in our cache.
 946
 947     lldb::addr_t isa_addr = LLDB_INVALID_ADDRESS;
 948     lldb::addr_t sel_addr =
 949         argument_values.GetValueAtIndex(sel_index)->GetScalar().ULongLong();
 950
 951     // Figure out the class this is being dispatched to and see if we've already
 952     // cached this method call,
 953     // If so we can push a run-to-address plan directly.  Otherwise we have to
 954     // figure out where
 955     // the implementation lives.
 956
 957     if (this_dispatch.is_super) {
 958       if (this_dispatch.is_super2) {
 959         // In the objc_msgSendSuper2 case, we don't get the object directly, we
 960         // get a structure containing
 961         // the object and the class to which the super message is being sent.
 962         // So we need to dig the super
 963         // out of the class and use that.
 964
 965         Value super_value(*(argument_values.GetValueAtIndex(obj_index)));
 966         super_value.GetScalar() += process->GetAddressByteSize();
 967         super_value.ResolveValue(&exe_ctx);
 968
 969         if (super_value.GetScalar().IsValid()) {
 970
 971           // isa_value now holds the class pointer.  The second word of the
 972           // class pointer is the super-class pointer:
 973           super_value.GetScalar() += process->GetAddressByteSize();
 974           super_value.ResolveValue(&exe_ctx);
 975           if (super_value.GetScalar().IsValid())
 976             isa_addr = super_value.GetScalar().ULongLong();
 977           else {
 978             if (log)
 979               log->Printf("Failed to extract the super class value from the "
 980                           "class in objc_super.");
 981           }
 982         } else {
 983           if (log)
 984             log->Printf("Failed to extract the class value from objc_super.");
 985         }
 986       } else {
 987         // In the objc_msgSendSuper case, we don't get the object directly, we
 988         // get a two element structure containing
 989         // the object and the super class to which the super message is being
 990         // sent.  So the class we want is
 991         // the second element of this structure.
 992
 993         Value super_value(*(argument_values.GetValueAtIndex(obj_index)));
 994         super_value.GetScalar() += process->GetAddressByteSize();
 995         super_value.ResolveValue(&exe_ctx);
 996
 997         if (super_value.GetScalar().IsValid()) {
 998           isa_addr = super_value.GetScalar().ULongLong();
 999         } else {
1000           if (log)
1001             log->Printf("Failed to extract the class value from objc_super.");
1002         }
1003       }
1004     } else {
1005       // In the direct dispatch case, the object->isa is the class pointer we
1006       // want.
1007
1008       // This is a little cheesy, but since object->isa is the first field,
1009       // making the object value a load address value and resolving it will get
1010       // the pointer sized data pointed to by that value...
1011
1012       // Note, it isn't a fatal error not to be able to get the address from the
1013       // object, since this might
1014       // be a "tagged pointer" which isn't a real object, but rather some word
1015       // length encoded dingus.
1016
1017       Value isa_value(*(argument_values.GetValueAtIndex(obj_index)));
1018
1019       isa_value.SetValueType(Value::eValueTypeLoadAddress);
1020       isa_value.ResolveValue(&exe_ctx);
1021       if (isa_value.GetScalar().IsValid()) {
1022         isa_addr = isa_value.GetScalar().ULongLong();
1023       } else {
1024         if (log)
1025           log->Printf("Failed to extract the isa value from object.");
1026       }
1027     }
1028
1029     // Okay, we've got the address of the class for which we're resolving this,
1030     // let's see if it's in our cache:
1031     lldb::addr_t impl_addr = LLDB_INVALID_ADDRESS;
1032
1033     if (isa_addr != LLDB_INVALID_ADDRESS) {
1034       if (log) {
1035         log->Printf("Resolving call for class - 0x%" PRIx64
1036                     " and selector - 0x%" PRIx64,
1037                     isa_addr, sel_addr);
1038       }
1039       ObjCLanguageRuntime *objc_runtime =
1040           thread.GetProcess()->GetObjCLanguageRuntime();
1041       assert(objc_runtime != NULL);
1042
1043       impl_addr = objc_runtime->LookupInMethodCache(isa_addr, sel_addr);
1044     }
1045
1046     if (impl_addr != LLDB_INVALID_ADDRESS) {
1047       // Yup, it was in the cache, so we can run to that address directly.
1048
1049       if (log)
1050         log->Printf("Found implementation address in cache: 0x%" PRIx64,
1051                     impl_addr);
1052
1053       ret_plan_sp.reset(
1054           new ThreadPlanRunToAddress(thread, impl_addr, stop_others));
1055     } else {
1056       // We haven't seen this class/selector pair yet.  Look it up.
1057       StreamString errors;
1058       Address impl_code_address;
1059
1060       ValueList dispatch_values;
1061
1062       // We've will inject a little function in the target that takes the
1063       // object, selector and some flags,
1064       // and figures out the implementation.  Looks like:
1065       //      void *__lldb_objc_find_implementation_for_selector (void *object,
1066       //                                                          void *sel,
1067       //                                                          int is_stret,
1068       //                                                          int is_super,
1069       //                                                          int is_super2,
1070       //                                                          int is_fixup,
1071       //                                                          int is_fixed,
1072       //                                                          int debug)
1073       // So set up the arguments for that call.
1074
1075       dispatch_values.PushValue(*(argument_values.GetValueAtIndex(obj_index)));
1076       dispatch_values.PushValue(*(argument_values.GetValueAtIndex(sel_index)));
1077
1078       Value flag_value;
1079       CompilerType clang_int_type =
1080           clang_ast_context->GetBuiltinTypeForEncodingAndBitSize(
1081               lldb::eEncodingSint, 32);
1082       flag_value.SetValueType(Value::eValueTypeScalar);
1083       // flag_value.SetContext (Value::eContextTypeClangType, clang_int_type);
1084       flag_value.SetCompilerType(clang_int_type);
1085
1086       if (this_dispatch.stret_return)
1087         flag_value.GetScalar() = 1;
1088       else
1089         flag_value.GetScalar() = 0;
1090       dispatch_values.PushValue(flag_value);
1091
1092       if (this_dispatch.is_super)
1093         flag_value.GetScalar() = 1;
1094       else
1095         flag_value.GetScalar() = 0;
1096       dispatch_values.PushValue(flag_value);
1097
1098       if (this_dispatch.is_super2)
1099         flag_value.GetScalar() = 1;
1100       else
1101         flag_value.GetScalar() = 0;
1102       dispatch_values.PushValue(flag_value);
1103
1104       switch (this_dispatch.fixedup) {
1105       case DispatchFunction::eFixUpNone:
1106         flag_value.GetScalar() = 0;
1107         dispatch_values.PushValue(flag_value);
1108         dispatch_values.PushValue(flag_value);
1109         break;
1110       case DispatchFunction::eFixUpFixed:
1111         flag_value.GetScalar() = 1;
1112         dispatch_values.PushValue(flag_value);
1113         flag_value.GetScalar() = 1;
1114         dispatch_values.PushValue(flag_value);
1115         break;
1116       case DispatchFunction::eFixUpToFix:
1117         flag_value.GetScalar() = 1;
1118         dispatch_values.PushValue(flag_value);
1119         flag_value.GetScalar() = 0;
1120         dispatch_values.PushValue(flag_value);
1121         break;
1122       }
1123       if (log && log->GetVerbose())
1124         flag_value.GetScalar() = 1;
1125       else
1126         flag_value.GetScalar() = 0; // FIXME - Set to 0 when debugging is done.
1127       dispatch_values.PushValue(flag_value);
1128
1129       // The step through code might have to fill in the cache, so it is not
1130       // safe to run only one thread.
1131       // So we override the stop_others value passed in to us here:
1132       const bool trampoline_stop_others = false;
1133       ret_plan_sp.reset(new AppleThreadPlanStepThroughObjCTrampoline(
1134           thread, this, dispatch_values, isa_addr, sel_addr,
1135           trampoline_stop_others));
1136       if (log) {
1137         StreamString s;
1138         ret_plan_sp->GetDescription(&s, eDescriptionLevelFull);
1139         log->Printf("Using ObjC step plan: %s.\n", s.GetData());
1140       }
1141     }
1142   }
1143
1144   return ret_plan_sp;
1145 }
1146
1147 FunctionCaller *
1148 AppleObjCTrampolineHandler::GetLookupImplementationFunctionCaller() {
1149   return m_impl_code->GetFunctionCaller();
1150 }