contrib/llvm/tools/lldb/source/Plugins/ABI/SysV-ppc/ABISysV_ppc.cpp

   1 //===-- ABISysV_ppc.cpp -----------------------------------------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "ABISysV_ppc.h"
  11
  12 // C Includes
  13 // C++ Includes
  14 // Other libraries and framework includes
  15 #include "llvm/ADT/STLExtras.h"
  16 #include "llvm/ADT/Triple.h"
  17
  18 // Project includes
  19 #include "lldb/Core/Module.h"
  20 #include "lldb/Core/PluginManager.h"
  21 #include "lldb/Core/RegisterValue.h"
  22 #include "lldb/Core/Value.h"
  23 #include "lldb/Core/ValueObjectConstResult.h"
  24 #include "lldb/Core/ValueObjectMemory.h"
  25 #include "lldb/Core/ValueObjectRegister.h"
  26 #include "lldb/Symbol/UnwindPlan.h"
  27 #include "lldb/Target/Process.h"
  28 #include "lldb/Target/RegisterContext.h"
  29 #include "lldb/Target/StackFrame.h"
  30 #include "lldb/Target/Target.h"
  31 #include "lldb/Target/Thread.h"
  32 #include "lldb/Utility/ConstString.h"
  33 #include "lldb/Utility/DataExtractor.h"
  34 #include "lldb/Utility/Log.h"
  35 #include "lldb/Utility/Status.h"
  36
  37 using namespace lldb;
  38 using namespace lldb_private;
  39
  40 enum dwarf_regnums {
  41   dwarf_r0 = 0,
  42   dwarf_r1,
  43   dwarf_r2,
  44   dwarf_r3,
  45   dwarf_r4,
  46   dwarf_r5,
  47   dwarf_r6,
  48   dwarf_r7,
  49   dwarf_r8,
  50   dwarf_r9,
  51   dwarf_r10,
  52   dwarf_r11,
  53   dwarf_r12,
  54   dwarf_r13,
  55   dwarf_r14,
  56   dwarf_r15,
  57   dwarf_r16,
  58   dwarf_r17,
  59   dwarf_r18,
  60   dwarf_r19,
  61   dwarf_r20,
  62   dwarf_r21,
  63   dwarf_r22,
  64   dwarf_r23,
  65   dwarf_r24,
  66   dwarf_r25,
  67   dwarf_r26,
  68   dwarf_r27,
  69   dwarf_r28,
  70   dwarf_r29,
  71   dwarf_r30,
  72   dwarf_r31,
  73   dwarf_f0,
  74   dwarf_f1,
  75   dwarf_f2,
  76   dwarf_f3,
  77   dwarf_f4,
  78   dwarf_f5,
  79   dwarf_f6,
  80   dwarf_f7,
  81   dwarf_f8,
  82   dwarf_f9,
  83   dwarf_f10,
  84   dwarf_f11,
  85   dwarf_f12,
  86   dwarf_f13,
  87   dwarf_f14,
  88   dwarf_f15,
  89   dwarf_f16,
  90   dwarf_f17,
  91   dwarf_f18,
  92   dwarf_f19,
  93   dwarf_f20,
  94   dwarf_f21,
  95   dwarf_f22,
  96   dwarf_f23,
  97   dwarf_f24,
  98   dwarf_f25,
  99   dwarf_f26,
 100   dwarf_f27,
 101   dwarf_f28,
 102   dwarf_f29,
 103   dwarf_f30,
 104   dwarf_f31,
 105   dwarf_cr,
 106   dwarf_fpscr,
 107   dwarf_xer = 101,
 108   dwarf_lr = 108,
 109   dwarf_ctr,
 110   dwarf_pc,
 111   dwarf_cfa,
 112 };
 113
 114 // Note that the size and offset will be updated by platform-specific classes.
 115 #define DEFINE_GPR(reg, alt, kind1, kind2, kind3, kind4)                       \
 116   {                                                                            \
 117     #reg, alt, 8, 0, eEncodingUint, eFormatHex, {kind1, kind2, kind3, kind4 }, \
 118                                                  nullptr, nullptr, nullptr, 0  \
 119   }
 120
 121 static const RegisterInfo g_register_infos[] = {
 122     // General purpose registers.             eh_frame,                 DWARF,
 123     // Generic,    Process Plugin
 124     DEFINE_GPR(r0, nullptr, dwarf_r0, dwarf_r0, LLDB_INVALID_REGNUM,
 125                LLDB_INVALID_REGNUM),
 126     DEFINE_GPR(r1, "sp", dwarf_r1, dwarf_r1, LLDB_REGNUM_GENERIC_SP,
 127                LLDB_INVALID_REGNUM),
 128     DEFINE_GPR(r2, nullptr, dwarf_r2, dwarf_r2, LLDB_INVALID_REGNUM,
 129                LLDB_INVALID_REGNUM),
 130     DEFINE_GPR(r3, "arg1", dwarf_r3, dwarf_r3, LLDB_REGNUM_GENERIC_ARG1,
 131                LLDB_INVALID_REGNUM),
 132     DEFINE_GPR(r4, "arg2", dwarf_r4, dwarf_r4, LLDB_REGNUM_GENERIC_ARG2,
 133                LLDB_INVALID_REGNUM),
 134     DEFINE_GPR(r5, "arg3", dwarf_r5, dwarf_r5, LLDB_REGNUM_GENERIC_ARG3,
 135                LLDB_INVALID_REGNUM),
 136     DEFINE_GPR(r6, "arg4", dwarf_r6, dwarf_r6, LLDB_REGNUM_GENERIC_ARG4,
 137                LLDB_INVALID_REGNUM),
 138     DEFINE_GPR(r7, "arg5", dwarf_r7, dwarf_r7, LLDB_REGNUM_GENERIC_ARG5,
 139                LLDB_INVALID_REGNUM),
 140     DEFINE_GPR(r8, "arg6", dwarf_r8, dwarf_r8, LLDB_REGNUM_GENERIC_ARG6,
 141                LLDB_INVALID_REGNUM),
 142     DEFINE_GPR(r9, "arg7", dwarf_r9, dwarf_r9, LLDB_REGNUM_GENERIC_ARG7,
 143                LLDB_INVALID_REGNUM),
 144     DEFINE_GPR(r10, "arg8", dwarf_r10, dwarf_r10, LLDB_REGNUM_GENERIC_ARG8,
 145                LLDB_INVALID_REGNUM),
 146     DEFINE_GPR(r11, nullptr, dwarf_r11, dwarf_r11, LLDB_INVALID_REGNUM,
 147                LLDB_INVALID_REGNUM),
 148     DEFINE_GPR(r12, nullptr, dwarf_r12, dwarf_r12, LLDB_INVALID_REGNUM,
 149                LLDB_INVALID_REGNUM),
 150     DEFINE_GPR(r13, nullptr, dwarf_r13, dwarf_r13, LLDB_INVALID_REGNUM,
 151                LLDB_INVALID_REGNUM),
 152     DEFINE_GPR(r14, nullptr, dwarf_r14, dwarf_r14, LLDB_INVALID_REGNUM,
 153                LLDB_INVALID_REGNUM),
 154     DEFINE_GPR(r15, nullptr, dwarf_r15, dwarf_r15, LLDB_INVALID_REGNUM,
 155                LLDB_INVALID_REGNUM),
 156     DEFINE_GPR(r16, nullptr, dwarf_r16, dwarf_r16, LLDB_INVALID_REGNUM,
 157                LLDB_INVALID_REGNUM),
 158     DEFINE_GPR(r17, nullptr, dwarf_r17, dwarf_r17, LLDB_INVALID_REGNUM,
 159                LLDB_INVALID_REGNUM),
 160     DEFINE_GPR(r18, nullptr, dwarf_r18, dwarf_r18, LLDB_INVALID_REGNUM,
 161                LLDB_INVALID_REGNUM),
 162     DEFINE_GPR(r19, nullptr, dwarf_r19, dwarf_r19, LLDB_INVALID_REGNUM,
 163                LLDB_INVALID_REGNUM),
 164     DEFINE_GPR(r20, nullptr, dwarf_r20, dwarf_r20, LLDB_INVALID_REGNUM,
 165                LLDB_INVALID_REGNUM),
 166     DEFINE_GPR(r21, nullptr, dwarf_r21, dwarf_r21, LLDB_INVALID_REGNUM,
 167                LLDB_INVALID_REGNUM),
 168     DEFINE_GPR(r22, nullptr, dwarf_r22, dwarf_r22, LLDB_INVALID_REGNUM,
 169                LLDB_INVALID_REGNUM),
 170     DEFINE_GPR(r23, nullptr, dwarf_r23, dwarf_r23, LLDB_INVALID_REGNUM,
 171                LLDB_INVALID_REGNUM),
 172     DEFINE_GPR(r24, nullptr, dwarf_r24, dwarf_r24, LLDB_INVALID_REGNUM,
 173                LLDB_INVALID_REGNUM),
 174     DEFINE_GPR(r25, nullptr, dwarf_r25, dwarf_r25, LLDB_INVALID_REGNUM,
 175                LLDB_INVALID_REGNUM),
 176     DEFINE_GPR(r26, nullptr, dwarf_r26, dwarf_r26, LLDB_INVALID_REGNUM,
 177                LLDB_INVALID_REGNUM),
 178     DEFINE_GPR(r27, nullptr, dwarf_r27, dwarf_r27, LLDB_INVALID_REGNUM,
 179                LLDB_INVALID_REGNUM),
 180     DEFINE_GPR(r28, nullptr, dwarf_r28, dwarf_r28, LLDB_INVALID_REGNUM,
 181                LLDB_INVALID_REGNUM),
 182     DEFINE_GPR(r29, nullptr, dwarf_r29, dwarf_r29, LLDB_INVALID_REGNUM,
 183                LLDB_INVALID_REGNUM),
 184     DEFINE_GPR(r30, nullptr, dwarf_r30, dwarf_r30, LLDB_INVALID_REGNUM,
 185                LLDB_INVALID_REGNUM),
 186     DEFINE_GPR(r31, nullptr, dwarf_r31, dwarf_r31, LLDB_INVALID_REGNUM,
 187                LLDB_INVALID_REGNUM),
 188     DEFINE_GPR(lr, "lr", dwarf_lr, dwarf_lr, LLDB_REGNUM_GENERIC_RA,
 189                LLDB_INVALID_REGNUM),
 190     DEFINE_GPR(cr, "cr", dwarf_cr, dwarf_cr, LLDB_REGNUM_GENERIC_FLAGS,
 191                LLDB_INVALID_REGNUM),
 192     DEFINE_GPR(xer, "xer", dwarf_xer, dwarf_xer, LLDB_INVALID_REGNUM,
 193                LLDB_INVALID_REGNUM),
 194     DEFINE_GPR(ctr, "ctr", dwarf_ctr, dwarf_ctr, LLDB_INVALID_REGNUM,
 195                LLDB_INVALID_REGNUM),
 196     DEFINE_GPR(pc, "pc", dwarf_pc, dwarf_pc, LLDB_REGNUM_GENERIC_PC,
 197                LLDB_INVALID_REGNUM),
 198     {nullptr,
 199      nullptr,
 200      8,
 201      0,
 202      eEncodingUint,
 203      eFormatHex,
 204      {dwarf_cfa, dwarf_cfa, LLDB_INVALID_REGNUM, LLDB_INVALID_REGNUM},
 205      nullptr,
 206      nullptr,
 207      nullptr,
 208      0}};
 209
 210 static const uint32_t k_num_register_infos =
 211     llvm::array_lengthof(g_register_infos);
 212
 213 const lldb_private::RegisterInfo *
 214 ABISysV_ppc::GetRegisterInfoArray(uint32_t &count) {
 215   count = k_num_register_infos;
 216   return g_register_infos;
 217 }
 218
 219 size_t ABISysV_ppc::GetRedZoneSize() const { return 224; }
 220
 221 //------------------------------------------------------------------
 222 // Static Functions
 223 //------------------------------------------------------------------
 224
 225 ABISP
 226 ABISysV_ppc::CreateInstance(lldb::ProcessSP process_sp, const ArchSpec &arch) {
 227   static ABISP g_abi_sp;
 228   if (arch.GetTriple().getArch() == llvm::Triple::ppc) {
 229     if (!g_abi_sp)
 230       g_abi_sp.reset(new ABISysV_ppc(process_sp));
 231     return g_abi_sp;
 232   }
 233   return ABISP();
 234 }
 235
 236 bool ABISysV_ppc::PrepareTrivialCall(Thread &thread, addr_t sp,
 237                                      addr_t func_addr, addr_t return_addr,
 238                                      llvm::ArrayRef<addr_t> args) const {
 239   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
 240
 241   if (log) {
 242     StreamString s;
 243     s.Printf("ABISysV_ppc::PrepareTrivialCall (tid = 0x%" PRIx64
 244              ", sp = 0x%" PRIx64 ", func_addr = 0x%" PRIx64
 245              ", return_addr = 0x%" PRIx64,
 246              thread.GetID(), (uint64_t)sp, (uint64_t)func_addr,
 247              (uint64_t)return_addr);
 248
 249     for (size_t i = 0; i < args.size(); ++i)
 250       s.Printf(", arg%" PRIu64 " = 0x%" PRIx64, static_cast<uint64_t>(i + 1),
 251                args[i]);
 252     s.PutCString(")");
 253     log->PutString(s.GetString());
 254   }
 255
 256   RegisterContext *reg_ctx = thread.GetRegisterContext().get();
 257   if (!reg_ctx)
 258     return false;
 259
 260   const RegisterInfo *reg_info = nullptr;
 261
 262   if (args.size() > 8) // TODO handle more than 8 arguments
 263     return false;
 264
 265   for (size_t i = 0; i < args.size(); ++i) {
 266     reg_info = reg_ctx->GetRegisterInfo(eRegisterKindGeneric,
 267                                         LLDB_REGNUM_GENERIC_ARG1 + i);
 268     if (log)
 269       log->Printf("About to write arg%" PRIu64 " (0x%" PRIx64 ") into %s",
 270                   static_cast<uint64_t>(i + 1), args[i], reg_info->name);
 271     if (!reg_ctx->WriteRegisterFromUnsigned(reg_info, args[i]))
 272       return false;
 273   }
 274
 275   // First, align the SP
 276
 277   if (log)
 278     log->Printf("16-byte aligning SP: 0x%" PRIx64 " to 0x%" PRIx64,
 279                 (uint64_t)sp, (uint64_t)(sp & ~0xfull));
 280
 281   sp &= ~(0xfull); // 16-byte alignment
 282
 283   sp -= 8;
 284
 285   Status error;
 286   const RegisterInfo *pc_reg_info =
 287       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);
 288   const RegisterInfo *sp_reg_info =
 289       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);
 290   ProcessSP process_sp(thread.GetProcess());
 291
 292   RegisterValue reg_value;
 293
 294   if (log)
 295     log->Printf("Pushing the return address onto the stack: 0x%" PRIx64
 296                 ": 0x%" PRIx64,
 297                 (uint64_t)sp, (uint64_t)return_addr);
 298
 299   // Save return address onto the stack
 300   if (!process_sp->WritePointerToMemory(sp, return_addr, error))
 301     return false;
 302
 303   // %r1 is set to the actual stack value.
 304
 305   if (log)
 306     log->Printf("Writing SP: 0x%" PRIx64, (uint64_t)sp);
 307
 308   if (!reg_ctx->WriteRegisterFromUnsigned(sp_reg_info, sp))
 309     return false;
 310
 311   // %pc is set to the address of the called function.
 312
 313   if (log)
 314     log->Printf("Writing IP: 0x%" PRIx64, (uint64_t)func_addr);
 315
 316   if (!reg_ctx->WriteRegisterFromUnsigned(pc_reg_info, func_addr))
 317     return false;
 318
 319   return true;
 320 }
 321
 322 static bool ReadIntegerArgument(Scalar &scalar, unsigned int bit_width,
 323                                 bool is_signed, Thread &thread,
 324                                 uint32_t *argument_register_ids,
 325                                 unsigned int &current_argument_register,
 326                                 addr_t &current_stack_argument) {
 327   if (bit_width > 64)
 328     return false; // Scalar can't hold large integer arguments
 329
 330   if (current_argument_register < 6) {
 331     scalar = thread.GetRegisterContext()->ReadRegisterAsUnsigned(
 332         argument_register_ids[current_argument_register], 0);
 333     current_argument_register++;
 334     if (is_signed)
 335       scalar.SignExtend(bit_width);
 336   } else {
 337     uint32_t byte_size = (bit_width + (8 - 1)) / 8;
 338     Status error;
 339     if (thread.GetProcess()->ReadScalarIntegerFromMemory(
 340             current_stack_argument, byte_size, is_signed, scalar, error)) {
 341       current_stack_argument += byte_size;
 342       return true;
 343     }
 344     return false;
 345   }
 346   return true;
 347 }
 348
 349 bool ABISysV_ppc::GetArgumentValues(Thread &thread, ValueList &values) const {
 350   unsigned int num_values = values.GetSize();
 351   unsigned int value_index;
 352
 353   // Extract the register context so we can read arguments from registers
 354
 355   RegisterContext *reg_ctx = thread.GetRegisterContext().get();
 356
 357   if (!reg_ctx)
 358     return false;
 359
 360   // Get the pointer to the first stack argument so we have a place to start
 361   // when reading data
 362
 363   addr_t sp = reg_ctx->GetSP(0);
 364
 365   if (!sp)
 366     return false;
 367
 368   addr_t current_stack_argument = sp + 48; // jump over return address
 369
 370   uint32_t argument_register_ids[8];
 371
 372   argument_register_ids[0] =
 373       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1)
 374           ->kinds[eRegisterKindLLDB];
 375   argument_register_ids[1] =
 376       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG2)
 377           ->kinds[eRegisterKindLLDB];
 378   argument_register_ids[2] =
 379       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG3)
 380           ->kinds[eRegisterKindLLDB];
 381   argument_register_ids[3] =
 382       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG4)
 383           ->kinds[eRegisterKindLLDB];
 384   argument_register_ids[4] =
 385       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG5)
 386           ->kinds[eRegisterKindLLDB];
 387   argument_register_ids[5] =
 388       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG6)
 389           ->kinds[eRegisterKindLLDB];
 390   argument_register_ids[6] =
 391       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG7)
 392           ->kinds[eRegisterKindLLDB];
 393   argument_register_ids[7] =
 394       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG8)
 395           ->kinds[eRegisterKindLLDB];
 396
 397   unsigned int current_argument_register = 0;
 398
 399   for (value_index = 0; value_index < num_values; ++value_index) {
 400     Value *value = values.GetValueAtIndex(value_index);
 401
 402     if (!value)
 403       return false;
 404
 405     // We currently only support extracting values with Clang QualTypes. Do we
 406     // care about others?
 407     CompilerType compiler_type = value->GetCompilerType();
 408     if (!compiler_type)
 409       return false;
 410     bool is_signed;
 411
 412     if (compiler_type.IsIntegerOrEnumerationType(is_signed)) {
 413       ReadIntegerArgument(value->GetScalar(), compiler_type.GetBitSize(&thread),
 414                           is_signed, thread, argument_register_ids,
 415                           current_argument_register, current_stack_argument);
 416     } else if (compiler_type.IsPointerType()) {
 417       ReadIntegerArgument(value->GetScalar(), compiler_type.GetBitSize(&thread),
 418                           false, thread, argument_register_ids,
 419                           current_argument_register, current_stack_argument);
 420     }
 421   }
 422
 423   return true;
 424 }
 425
 426 Status ABISysV_ppc::SetReturnValueObject(lldb::StackFrameSP &frame_sp,
 427                                          lldb::ValueObjectSP &new_value_sp) {
 428   Status error;
 429   if (!new_value_sp) {
 430     error.SetErrorString("Empty value object for return value.");
 431     return error;
 432   }
 433
 434   CompilerType compiler_type = new_value_sp->GetCompilerType();
 435   if (!compiler_type) {
 436     error.SetErrorString("Null clang type for return value.");
 437     return error;
 438   }
 439
 440   Thread *thread = frame_sp->GetThread().get();
 441
 442   bool is_signed;
 443   uint32_t count;
 444   bool is_complex;
 445
 446   RegisterContext *reg_ctx = thread->GetRegisterContext().get();
 447
 448   bool set_it_simple = false;
 449   if (compiler_type.IsIntegerOrEnumerationType(is_signed) ||
 450       compiler_type.IsPointerType()) {
 451     const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoByName("r3", 0);
 452
 453     DataExtractor data;
 454     Status data_error;
 455     size_t num_bytes = new_value_sp->GetData(data, data_error);
 456     if (data_error.Fail()) {
 457       error.SetErrorStringWithFormat(
 458           "Couldn't convert return value to raw data: %s",
 459           data_error.AsCString());
 460       return error;
 461     }
 462     lldb::offset_t offset = 0;
 463     if (num_bytes <= 8) {
 464       uint64_t raw_value = data.GetMaxU64(&offset, num_bytes);
 465
 466       if (reg_ctx->WriteRegisterFromUnsigned(reg_info, raw_value))
 467         set_it_simple = true;
 468     } else {
 469       error.SetErrorString("We don't support returning longer than 64 bit "
 470                            "integer values at present.");
 471     }
 472   } else if (compiler_type.IsFloatingPointType(count, is_complex)) {
 473     if (is_complex)
 474       error.SetErrorString(
 475           "We don't support returning complex values at present");
 476     else {
 477       size_t bit_width = compiler_type.GetBitSize(frame_sp.get());
 478       if (bit_width <= 64) {
 479         DataExtractor data;
 480         Status data_error;
 481         size_t num_bytes = new_value_sp->GetData(data, data_error);
 482         if (data_error.Fail()) {
 483           error.SetErrorStringWithFormat(
 484               "Couldn't convert return value to raw data: %s",
 485               data_error.AsCString());
 486           return error;
 487         }
 488
 489         unsigned char buffer[16];
 490         ByteOrder byte_order = data.GetByteOrder();
 491
 492         data.CopyByteOrderedData(0, num_bytes, buffer, 16, byte_order);
 493         set_it_simple = true;
 494       } else {
 495         // FIXME - don't know how to do 80 bit long doubles yet.
 496         error.SetErrorString(
 497             "We don't support returning float values > 64 bits at present");
 498       }
 499     }
 500   }
 501
 502   if (!set_it_simple) {
 503     // Okay we've got a structure or something that doesn't fit in a simple
 504     // register. We should figure out where it really goes, but we don't
 505     // support this yet.
 506     error.SetErrorString("We only support setting simple integer and float "
 507                          "return types at present.");
 508   }
 509
 510   return error;
 511 }
 512
 513 ValueObjectSP ABISysV_ppc::GetReturnValueObjectSimple(
 514     Thread &thread, CompilerType &return_compiler_type) const {
 515   ValueObjectSP return_valobj_sp;
 516   Value value;
 517
 518   if (!return_compiler_type)
 519     return return_valobj_sp;
 520
 521   // value.SetContext (Value::eContextTypeClangType, return_value_type);
 522   value.SetCompilerType(return_compiler_type);
 523
 524   RegisterContext *reg_ctx = thread.GetRegisterContext().get();
 525   if (!reg_ctx)
 526     return return_valobj_sp;
 527
 528   const uint32_t type_flags = return_compiler_type.GetTypeInfo();
 529   if (type_flags & eTypeIsScalar) {
 530     value.SetValueType(Value::eValueTypeScalar);
 531
 532     bool success = false;
 533     if (type_flags & eTypeIsInteger) {
 534       // Extract the register context so we can read arguments from registers
 535
 536       const size_t byte_size = return_compiler_type.GetByteSize(nullptr);
 537       uint64_t raw_value = thread.GetRegisterContext()->ReadRegisterAsUnsigned(
 538           reg_ctx->GetRegisterInfoByName("r3", 0), 0);
 539       const bool is_signed = (type_flags & eTypeIsSigned) != 0;
 540       switch (byte_size) {
 541       default:
 542         break;
 543
 544       case sizeof(uint64_t):
 545         if (is_signed)
 546           value.GetScalar() = (int64_t)(raw_value);
 547         else
 548           value.GetScalar() = (uint64_t)(raw_value);
 549         success = true;
 550         break;
 551
 552       case sizeof(uint32_t):
 553         if (is_signed)
 554           value.GetScalar() = (int32_t)(raw_value & UINT32_MAX);
 555         else
 556           value.GetScalar() = (uint32_t)(raw_value & UINT32_MAX);
 557         success = true;
 558         break;
 559
 560       case sizeof(uint16_t):
 561         if (is_signed)
 562           value.GetScalar() = (int16_t)(raw_value & UINT16_MAX);
 563         else
 564           value.GetScalar() = (uint16_t)(raw_value & UINT16_MAX);
 565         success = true;
 566         break;
 567
 568       case sizeof(uint8_t):
 569         if (is_signed)
 570           value.GetScalar() = (int8_t)(raw_value & UINT8_MAX);
 571         else
 572           value.GetScalar() = (uint8_t)(raw_value & UINT8_MAX);
 573         success = true;
 574         break;
 575       }
 576     } else if (type_flags & eTypeIsFloat) {
 577       if (type_flags & eTypeIsComplex) {
 578         // Don't handle complex yet.
 579       } else {
 580         const size_t byte_size = return_compiler_type.GetByteSize(nullptr);
 581         if (byte_size <= sizeof(long double)) {
 582           const RegisterInfo *f1_info = reg_ctx->GetRegisterInfoByName("f1", 0);
 583           RegisterValue f1_value;
 584           if (reg_ctx->ReadRegister(f1_info, f1_value)) {
 585             DataExtractor data;
 586             if (f1_value.GetData(data)) {
 587               lldb::offset_t offset = 0;
 588               if (byte_size == sizeof(float)) {
 589                 value.GetScalar() = (float)data.GetFloat(&offset);
 590                 success = true;
 591               } else if (byte_size == sizeof(double)) {
 592                 value.GetScalar() = (double)data.GetDouble(&offset);
 593                 success = true;
 594               }
 595             }
 596           }
 597         }
 598       }
 599     }
 600
 601     if (success)
 602       return_valobj_sp = ValueObjectConstResult::Create(
 603           thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));
 604   } else if (type_flags & eTypeIsPointer) {
 605     unsigned r3_id =
 606         reg_ctx->GetRegisterInfoByName("r3", 0)->kinds[eRegisterKindLLDB];
 607     value.GetScalar() =
 608         (uint64_t)thread.GetRegisterContext()->ReadRegisterAsUnsigned(r3_id, 0);
 609     value.SetValueType(Value::eValueTypeScalar);
 610     return_valobj_sp = ValueObjectConstResult::Create(
 611         thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));
 612   } else if (type_flags & eTypeIsVector) {
 613     const size_t byte_size = return_compiler_type.GetByteSize(nullptr);
 614     if (byte_size > 0) {
 615       const RegisterInfo *altivec_reg = reg_ctx->GetRegisterInfoByName("v2", 0);
 616       if (altivec_reg) {
 617         if (byte_size <= altivec_reg->byte_size) {
 618           ProcessSP process_sp(thread.GetProcess());
 619           if (process_sp) {
 620             std::unique_ptr<DataBufferHeap> heap_data_ap(
 621                 new DataBufferHeap(byte_size, 0));
 622             const ByteOrder byte_order = process_sp->GetByteOrder();
 623             RegisterValue reg_value;
 624             if (reg_ctx->ReadRegister(altivec_reg, reg_value)) {
 625               Status error;
 626               if (reg_value.GetAsMemoryData(
 627                       altivec_reg, heap_data_ap->GetBytes(),
 628                       heap_data_ap->GetByteSize(), byte_order, error)) {
 629                 DataExtractor data(DataBufferSP(heap_data_ap.release()),
 630                                    byte_order, process_sp->GetTarget()
 631                                                    .GetArchitecture()
 632                                                    .GetAddressByteSize());
 633                 return_valobj_sp = ValueObjectConstResult::Create(
 634                     &thread, return_compiler_type, ConstString(""), data);
 635               }
 636             }
 637           }
 638         }
 639       }
 640     }
 641   }
 642
 643   return return_valobj_sp;
 644 }
 645
 646 ValueObjectSP ABISysV_ppc::GetReturnValueObjectImpl(
 647     Thread &thread, CompilerType &return_compiler_type) const {
 648   ValueObjectSP return_valobj_sp;
 649
 650   if (!return_compiler_type)
 651     return return_valobj_sp;
 652
 653   ExecutionContext exe_ctx(thread.shared_from_this());
 654   return_valobj_sp = GetReturnValueObjectSimple(thread, return_compiler_type);
 655   if (return_valobj_sp)
 656     return return_valobj_sp;
 657
 658   RegisterContextSP reg_ctx_sp = thread.GetRegisterContext();
 659   if (!reg_ctx_sp)
 660     return return_valobj_sp;
 661
 662   const size_t bit_width = return_compiler_type.GetBitSize(&thread);
 663   if (return_compiler_type.IsAggregateType()) {
 664     Target *target = exe_ctx.GetTargetPtr();
 665     bool is_memory = true;
 666     if (bit_width <= 128) {
 667       ByteOrder target_byte_order = target->GetArchitecture().GetByteOrder();
 668       DataBufferSP data_sp(new DataBufferHeap(16, 0));
 669       DataExtractor return_ext(data_sp, target_byte_order,
 670                                target->GetArchitecture().GetAddressByteSize());
 671
 672       const RegisterInfo *r3_info = reg_ctx_sp->GetRegisterInfoByName("r3", 0);
 673       const RegisterInfo *rdx_info =
 674           reg_ctx_sp->GetRegisterInfoByName("rdx", 0);
 675
 676       RegisterValue r3_value, rdx_value;
 677       reg_ctx_sp->ReadRegister(r3_info, r3_value);
 678       reg_ctx_sp->ReadRegister(rdx_info, rdx_value);
 679
 680       DataExtractor r3_data, rdx_data;
 681
 682       r3_value.GetData(r3_data);
 683       rdx_value.GetData(rdx_data);
 684
 685       uint32_t fp_bytes =
 686           0; // Tracks how much of the xmm registers we've consumed so far
 687       uint32_t integer_bytes =
 688           0; // Tracks how much of the r3/rds registers we've consumed so far
 689
 690       const uint32_t num_children = return_compiler_type.GetNumFields();
 691
 692       // Since we are in the small struct regime, assume we are not in memory.
 693       is_memory = false;
 694
 695       for (uint32_t idx = 0; idx < num_children; idx++) {
 696         std::string name;
 697         uint64_t field_bit_offset = 0;
 698         bool is_signed;
 699         bool is_complex;
 700         uint32_t count;
 701
 702         CompilerType field_compiler_type = return_compiler_type.GetFieldAtIndex(
 703             idx, name, &field_bit_offset, nullptr, nullptr);
 704         const size_t field_bit_width = field_compiler_type.GetBitSize(&thread);
 705
 706         // If there are any unaligned fields, this is stored in memory.
 707         if (field_bit_offset % field_bit_width != 0) {
 708           is_memory = true;
 709           break;
 710         }
 711
 712         uint32_t field_byte_width = field_bit_width / 8;
 713         uint32_t field_byte_offset = field_bit_offset / 8;
 714
 715         DataExtractor *copy_from_extractor = nullptr;
 716         uint32_t copy_from_offset = 0;
 717
 718         if (field_compiler_type.IsIntegerOrEnumerationType(is_signed) ||
 719             field_compiler_type.IsPointerType()) {
 720           if (integer_bytes < 8) {
 721             if (integer_bytes + field_byte_width <= 8) {
 722               // This is in RAX, copy from register to our result structure:
 723               copy_from_extractor = &r3_data;
 724               copy_from_offset = integer_bytes;
 725               integer_bytes += field_byte_width;
 726             } else {
 727               // The next field wouldn't fit in the remaining space, so we
 728               // pushed it to rdx.
 729               copy_from_extractor = &rdx_data;
 730               copy_from_offset = 0;
 731               integer_bytes = 8 + field_byte_width;
 732             }
 733           } else if (integer_bytes + field_byte_width <= 16) {
 734             copy_from_extractor = &rdx_data;
 735             copy_from_offset = integer_bytes - 8;
 736             integer_bytes += field_byte_width;
 737           } else {
 738             // The last field didn't fit.  I can't see how that would happen
 739             // w/o the overall size being greater than 16 bytes.  For now,
 740             // return a nullptr return value object.
 741             return return_valobj_sp;
 742           }
 743         } else if (field_compiler_type.IsFloatingPointType(count, is_complex)) {
 744           // Structs with long doubles are always passed in memory.
 745           if (field_bit_width == 128) {
 746             is_memory = true;
 747             break;
 748           } else if (field_bit_width == 64) {
 749             copy_from_offset = 0;
 750             fp_bytes += field_byte_width;
 751           } else if (field_bit_width == 32) {
 752             // This one is kind of complicated.  If we are in an "eightbyte"
 753             // with another float, we'll be stuffed into an xmm register with
 754             // it.  If we are in an "eightbyte" with one or more ints, then we
 755             // will be stuffed into the appropriate GPR with them.
 756             bool in_gpr;
 757             if (field_byte_offset % 8 == 0) {
 758               // We are at the beginning of one of the eightbytes, so check the
 759               // next element (if any)
 760               if (idx == num_children - 1)
 761                 in_gpr = false;
 762               else {
 763                 uint64_t next_field_bit_offset = 0;
 764                 CompilerType next_field_compiler_type =
 765                     return_compiler_type.GetFieldAtIndex(idx + 1, name,
 766                                                          &next_field_bit_offset,
 767                                                          nullptr, nullptr);
 768                 if (next_field_compiler_type.IsIntegerOrEnumerationType(
 769                         is_signed))
 770                   in_gpr = true;
 771                 else {
 772                   copy_from_offset = 0;
 773                   in_gpr = false;
 774                 }
 775               }
 776             } else if (field_byte_offset % 4 == 0) {
 777               // We are inside of an eightbyte, so see if the field before us
 778               // is floating point: This could happen if somebody put padding
 779               // in the structure.
 780               if (idx == 0)
 781                 in_gpr = false;
 782               else {
 783                 uint64_t prev_field_bit_offset = 0;
 784                 CompilerType prev_field_compiler_type =
 785                     return_compiler_type.GetFieldAtIndex(idx - 1, name,
 786                                                          &prev_field_bit_offset,
 787                                                          nullptr, nullptr);
 788                 if (prev_field_compiler_type.IsIntegerOrEnumerationType(
 789                         is_signed))
 790                   in_gpr = true;
 791                 else {
 792                   copy_from_offset = 4;
 793                   in_gpr = false;
 794                 }
 795               }
 796             } else {
 797               is_memory = true;
 798               continue;
 799             }
 800
 801             // Okay, we've figured out whether we are in GPR or XMM, now figure
 802             // out which one.
 803             if (in_gpr) {
 804               if (integer_bytes < 8) {
 805                 // This is in RAX, copy from register to our result structure:
 806                 copy_from_extractor = &r3_data;
 807                 copy_from_offset = integer_bytes;
 808                 integer_bytes += field_byte_width;
 809               } else {
 810                 copy_from_extractor = &rdx_data;
 811                 copy_from_offset = integer_bytes - 8;
 812                 integer_bytes += field_byte_width;
 813               }
 814             } else {
 815               fp_bytes += field_byte_width;
 816             }
 817           }
 818         }
 819
 820         // These two tests are just sanity checks.  If I somehow get the type
 821         // calculation wrong above it is better to just return nothing than to
 822         // assert or crash.
 823         if (!copy_from_extractor)
 824           return return_valobj_sp;
 825         if (copy_from_offset + field_byte_width >
 826             copy_from_extractor->GetByteSize())
 827           return return_valobj_sp;
 828
 829         copy_from_extractor->CopyByteOrderedData(
 830             copy_from_offset, field_byte_width,
 831             data_sp->GetBytes() + field_byte_offset, field_byte_width,
 832             target_byte_order);
 833       }
 834
 835       if (!is_memory) {
 836         // The result is in our data buffer.  Let's make a variable object out
 837         // of it:
 838         return_valobj_sp = ValueObjectConstResult::Create(
 839             &thread, return_compiler_type, ConstString(""), return_ext);
 840       }
 841     }
 842
 843     // FIXME: This is just taking a guess, r3 may very well no longer hold the
 844     // return storage location.
 845     // If we are going to do this right, when we make a new frame we should
 846     // check to see if it uses a memory return, and if we are at the first
 847     // instruction and if so stash away the return location.  Then we would
 848     // only return the memory return value if we know it is valid.
 849
 850     if (is_memory) {
 851       unsigned r3_id =
 852           reg_ctx_sp->GetRegisterInfoByName("r3", 0)->kinds[eRegisterKindLLDB];
 853       lldb::addr_t storage_addr =
 854           (uint64_t)thread.GetRegisterContext()->ReadRegisterAsUnsigned(r3_id,
 855                                                                         0);
 856       return_valobj_sp = ValueObjectMemory::Create(
 857           &thread, "", Address(storage_addr, nullptr), return_compiler_type);
 858     }
 859   }
 860
 861   return return_valobj_sp;
 862 }
 863
 864 bool ABISysV_ppc::CreateFunctionEntryUnwindPlan(UnwindPlan &unwind_plan) {
 865   unwind_plan.Clear();
 866   unwind_plan.SetRegisterKind(eRegisterKindDWARF);
 867
 868   uint32_t lr_reg_num = dwarf_lr;
 869   uint32_t sp_reg_num = dwarf_r1;
 870   uint32_t pc_reg_num = dwarf_pc;
 871
 872   UnwindPlan::RowSP row(new UnwindPlan::Row);
 873
 874   // Our Call Frame Address is the stack pointer value
 875   row->GetCFAValue().SetIsRegisterPlusOffset(sp_reg_num, 0);
 876
 877   // The previous PC is in the LR
 878   row->SetRegisterLocationToRegister(pc_reg_num, lr_reg_num, true);
 879   unwind_plan.AppendRow(row);
 880
 881   // All other registers are the same.
 882
 883   unwind_plan.SetSourceName("ppc at-func-entry default");
 884   unwind_plan.SetSourcedFromCompiler(eLazyBoolNo);
 885
 886   return true;
 887 }
 888
 889 bool ABISysV_ppc::CreateDefaultUnwindPlan(UnwindPlan &unwind_plan) {
 890   unwind_plan.Clear();
 891   unwind_plan.SetRegisterKind(eRegisterKindDWARF);
 892
 893   uint32_t sp_reg_num = dwarf_r1;
 894   uint32_t pc_reg_num = dwarf_lr;
 895
 896   UnwindPlan::RowSP row(new UnwindPlan::Row);
 897
 898   const int32_t ptr_size = 4;
 899   row->GetCFAValue().SetIsRegisterDereferenced(sp_reg_num);
 900
 901   row->SetRegisterLocationToAtCFAPlusOffset(pc_reg_num, ptr_size * 1, true);
 902   row->SetRegisterLocationToIsCFAPlusOffset(sp_reg_num, 0, true);
 903
 904   unwind_plan.AppendRow(row);
 905   unwind_plan.SetSourceName("ppc default unwind plan");
 906   unwind_plan.SetSourcedFromCompiler(eLazyBoolNo);
 907   unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo);
 908   unwind_plan.SetReturnAddressRegister(dwarf_lr);
 909   return true;
 910 }
 911
 912 bool ABISysV_ppc::RegisterIsVolatile(const RegisterInfo *reg_info) {
 913   return !RegisterIsCalleeSaved(reg_info);
 914 }
 915
 916 // See "Register Usage" in the
 917 // "System V Application Binary Interface"
 918 // "64-bit PowerPC ELF Application Binary Interface Supplement" current version
 919 // is 1.9 released 2004 at http://refspecs.linuxfoundation.org/ELF/ppc/PPC-
 920 // elf64abi-1.9.pdf
 921
 922 bool ABISysV_ppc::RegisterIsCalleeSaved(const RegisterInfo *reg_info) {
 923   if (reg_info) {
 924     // Preserved registers are :
 925     //    r1,r2,r13-r31
 926     //    f14-f31 (not yet)
 927     //    v20-v31 (not yet)
 928     //    vrsave (not yet)
 929
 930     const char *name = reg_info->name;
 931     if (name[0] == 'r') {
 932       if ((name[1] == '1' || name[1] == '2') && name[2] == '\0')
 933         return true;
 934       if (name[1] == '1' && name[2] > '2')
 935         return true;
 936       if ((name[1] == '2' || name[1] == '3') && name[2] != '\0')
 937         return true;
 938     }
 939
 940     if (name[0] == 'f' && name[1] >= '0' && name[1] <= '9') {
 941       if (name[3] == '1' && name[4] >= '4')
 942         return true;
 943       if ((name[3] == '2' || name[3] == '3') && name[4] != '\0')
 944         return true;
 945     }
 946
 947     if (name[0] == 's' && name[1] == 'p' && name[2] == '\0') // sp
 948       return true;
 949     if (name[0] == 'f' && name[1] == 'p' && name[2] == '\0') // fp
 950       return true;
 951     if (name[0] == 'p' && name[1] == 'c' && name[2] == '\0') // pc
 952       return true;
 953   }
 954   return false;
 955 }
 956
 957 void ABISysV_ppc::Initialize() {
 958   PluginManager::RegisterPlugin(GetPluginNameStatic(),
 959                                 "System V ABI for ppc targets", CreateInstance);
 960 }
 961
 962 void ABISysV_ppc::Terminate() {
 963   PluginManager::UnregisterPlugin(CreateInstance);
 964 }
 965
 966 lldb_private::ConstString ABISysV_ppc::GetPluginNameStatic() {
 967   static ConstString g_name("sysv-ppc");
 968   return g_name;
 969 }
 970
 971 //------------------------------------------------------------------
 972 // PluginInterface protocol
 973 //------------------------------------------------------------------
 974
 975 lldb_private::ConstString ABISysV_ppc::GetPluginName() {
 976   return GetPluginNameStatic();
 977 }
 978
 979 uint32_t ABISysV_ppc::GetPluginVersion() { return 1; }