lldb/source/Plugins/ABI/PowerPC/ABISysV_ppc.cpp

   1 //===-- ABISysV_ppc.cpp ---------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "ABISysV_ppc.h"
  10
  11 #include "llvm/ADT/STLExtras.h"
  12 #include "llvm/TargetParser/Triple.h"
  13
  14 #include "lldb/Core/Module.h"
  15 #include "lldb/Core/PluginManager.h"
  16 #include "lldb/Core/Value.h"
  17 #include "lldb/Core/ValueObjectConstResult.h"
  18 #include "lldb/Core/ValueObjectMemory.h"
  19 #include "lldb/Core/ValueObjectRegister.h"
  20 #include "lldb/Symbol/UnwindPlan.h"
  21 #include "lldb/Target/Process.h"
  22 #include "lldb/Target/RegisterContext.h"
  23 #include "lldb/Target/StackFrame.h"
  24 #include "lldb/Target/Target.h"
  25 #include "lldb/Target/Thread.h"
  26 #include "lldb/Utility/ConstString.h"
  27 #include "lldb/Utility/DataExtractor.h"
  28 #include "lldb/Utility/LLDBLog.h"
  29 #include "lldb/Utility/Log.h"
  30 #include "lldb/Utility/RegisterValue.h"
  31 #include "lldb/Utility/Status.h"
  32 #include <optional>
  33
  34 using namespace lldb;
  35 using namespace lldb_private;
  36
  37 LLDB_PLUGIN_DEFINE(ABISysV_ppc)
  38
  39 enum dwarf_regnums {
  40   dwarf_r0 = 0,
  41   dwarf_r1,
  42   dwarf_r2,
  43   dwarf_r3,
  44   dwarf_r4,
  45   dwarf_r5,
  46   dwarf_r6,
  47   dwarf_r7,
  48   dwarf_r8,
  49   dwarf_r9,
  50   dwarf_r10,
  51   dwarf_r11,
  52   dwarf_r12,
  53   dwarf_r13,
  54   dwarf_r14,
  55   dwarf_r15,
  56   dwarf_r16,
  57   dwarf_r17,
  58   dwarf_r18,
  59   dwarf_r19,
  60   dwarf_r20,
  61   dwarf_r21,
  62   dwarf_r22,
  63   dwarf_r23,
  64   dwarf_r24,
  65   dwarf_r25,
  66   dwarf_r26,
  67   dwarf_r27,
  68   dwarf_r28,
  69   dwarf_r29,
  70   dwarf_r30,
  71   dwarf_r31,
  72   dwarf_f0,
  73   dwarf_f1,
  74   dwarf_f2,
  75   dwarf_f3,
  76   dwarf_f4,
  77   dwarf_f5,
  78   dwarf_f6,
  79   dwarf_f7,
  80   dwarf_f8,
  81   dwarf_f9,
  82   dwarf_f10,
  83   dwarf_f11,
  84   dwarf_f12,
  85   dwarf_f13,
  86   dwarf_f14,
  87   dwarf_f15,
  88   dwarf_f16,
  89   dwarf_f17,
  90   dwarf_f18,
  91   dwarf_f19,
  92   dwarf_f20,
  93   dwarf_f21,
  94   dwarf_f22,
  95   dwarf_f23,
  96   dwarf_f24,
  97   dwarf_f25,
  98   dwarf_f26,
  99   dwarf_f27,
 100   dwarf_f28,
 101   dwarf_f29,
 102   dwarf_f30,
 103   dwarf_f31,
 104   dwarf_cr,
 105   dwarf_fpscr,
 106   dwarf_xer = 101,
 107   dwarf_lr = 108,
 108   dwarf_ctr,
 109   dwarf_pc,
 110   dwarf_cfa,
 111 };
 112
 113 // Note that the size and offset will be updated by platform-specific classes.
 114 #define DEFINE_GPR(reg, alt, kind1, kind2, kind3, kind4)                       \
 115   {                                                                            \
 116     #reg, alt, 8, 0, eEncodingUint, eFormatHex, {kind1, kind2, kind3, kind4 }, \
 117                                                  nullptr, nullptr, nullptr,    \
 118   }
 119
 120 static const RegisterInfo g_register_infos[] = {
 121     // General purpose registers.             eh_frame,                 DWARF,
 122     // Generic,    Process Plugin
 123     DEFINE_GPR(r0, nullptr, dwarf_r0, dwarf_r0, LLDB_INVALID_REGNUM,
 124                LLDB_INVALID_REGNUM),
 125     DEFINE_GPR(r1, nullptr, dwarf_r1, dwarf_r1, LLDB_REGNUM_GENERIC_SP,
 126                LLDB_INVALID_REGNUM),
 127     DEFINE_GPR(r2, nullptr, dwarf_r2, dwarf_r2, LLDB_INVALID_REGNUM,
 128                LLDB_INVALID_REGNUM),
 129     DEFINE_GPR(r3, nullptr, dwarf_r3, dwarf_r3, LLDB_REGNUM_GENERIC_ARG1,
 130                LLDB_INVALID_REGNUM),
 131     DEFINE_GPR(r4, nullptr, dwarf_r4, dwarf_r4, LLDB_REGNUM_GENERIC_ARG2,
 132                LLDB_INVALID_REGNUM),
 133     DEFINE_GPR(r5, nullptr, dwarf_r5, dwarf_r5, LLDB_REGNUM_GENERIC_ARG3,
 134                LLDB_INVALID_REGNUM),
 135     DEFINE_GPR(r6, nullptr, dwarf_r6, dwarf_r6, LLDB_REGNUM_GENERIC_ARG4,
 136                LLDB_INVALID_REGNUM),
 137     DEFINE_GPR(r7, nullptr, dwarf_r7, dwarf_r7, LLDB_REGNUM_GENERIC_ARG5,
 138                LLDB_INVALID_REGNUM),
 139     DEFINE_GPR(r8, nullptr, dwarf_r8, dwarf_r8, LLDB_REGNUM_GENERIC_ARG6,
 140                LLDB_INVALID_REGNUM),
 141     DEFINE_GPR(r9, nullptr, dwarf_r9, dwarf_r9, LLDB_REGNUM_GENERIC_ARG7,
 142                LLDB_INVALID_REGNUM),
 143     DEFINE_GPR(r10, nullptr, dwarf_r10, dwarf_r10, LLDB_REGNUM_GENERIC_ARG8,
 144                LLDB_INVALID_REGNUM),
 145     DEFINE_GPR(r11, nullptr, dwarf_r11, dwarf_r11, LLDB_INVALID_REGNUM,
 146                LLDB_INVALID_REGNUM),
 147     DEFINE_GPR(r12, nullptr, dwarf_r12, dwarf_r12, LLDB_INVALID_REGNUM,
 148                LLDB_INVALID_REGNUM),
 149     DEFINE_GPR(r13, nullptr, dwarf_r13, dwarf_r13, LLDB_INVALID_REGNUM,
 150                LLDB_INVALID_REGNUM),
 151     DEFINE_GPR(r14, nullptr, dwarf_r14, dwarf_r14, LLDB_INVALID_REGNUM,
 152                LLDB_INVALID_REGNUM),
 153     DEFINE_GPR(r15, nullptr, dwarf_r15, dwarf_r15, LLDB_INVALID_REGNUM,
 154                LLDB_INVALID_REGNUM),
 155     DEFINE_GPR(r16, nullptr, dwarf_r16, dwarf_r16, LLDB_INVALID_REGNUM,
 156                LLDB_INVALID_REGNUM),
 157     DEFINE_GPR(r17, nullptr, dwarf_r17, dwarf_r17, LLDB_INVALID_REGNUM,
 158                LLDB_INVALID_REGNUM),
 159     DEFINE_GPR(r18, nullptr, dwarf_r18, dwarf_r18, LLDB_INVALID_REGNUM,
 160                LLDB_INVALID_REGNUM),
 161     DEFINE_GPR(r19, nullptr, dwarf_r19, dwarf_r19, LLDB_INVALID_REGNUM,
 162                LLDB_INVALID_REGNUM),
 163     DEFINE_GPR(r20, nullptr, dwarf_r20, dwarf_r20, LLDB_INVALID_REGNUM,
 164                LLDB_INVALID_REGNUM),
 165     DEFINE_GPR(r21, nullptr, dwarf_r21, dwarf_r21, LLDB_INVALID_REGNUM,
 166                LLDB_INVALID_REGNUM),
 167     DEFINE_GPR(r22, nullptr, dwarf_r22, dwarf_r22, LLDB_INVALID_REGNUM,
 168                LLDB_INVALID_REGNUM),
 169     DEFINE_GPR(r23, nullptr, dwarf_r23, dwarf_r23, LLDB_INVALID_REGNUM,
 170                LLDB_INVALID_REGNUM),
 171     DEFINE_GPR(r24, nullptr, dwarf_r24, dwarf_r24, LLDB_INVALID_REGNUM,
 172                LLDB_INVALID_REGNUM),
 173     DEFINE_GPR(r25, nullptr, dwarf_r25, dwarf_r25, LLDB_INVALID_REGNUM,
 174                LLDB_INVALID_REGNUM),
 175     DEFINE_GPR(r26, nullptr, dwarf_r26, dwarf_r26, LLDB_INVALID_REGNUM,
 176                LLDB_INVALID_REGNUM),
 177     DEFINE_GPR(r27, nullptr, dwarf_r27, dwarf_r27, LLDB_INVALID_REGNUM,
 178                LLDB_INVALID_REGNUM),
 179     DEFINE_GPR(r28, nullptr, dwarf_r28, dwarf_r28, LLDB_INVALID_REGNUM,
 180                LLDB_INVALID_REGNUM),
 181     DEFINE_GPR(r29, nullptr, dwarf_r29, dwarf_r29, LLDB_INVALID_REGNUM,
 182                LLDB_INVALID_REGNUM),
 183     DEFINE_GPR(r30, nullptr, dwarf_r30, dwarf_r30, LLDB_INVALID_REGNUM,
 184                LLDB_INVALID_REGNUM),
 185     DEFINE_GPR(r31, nullptr, dwarf_r31, dwarf_r31, LLDB_INVALID_REGNUM,
 186                LLDB_INVALID_REGNUM),
 187     DEFINE_GPR(lr, nullptr, dwarf_lr, dwarf_lr, LLDB_REGNUM_GENERIC_RA,
 188                LLDB_INVALID_REGNUM),
 189     DEFINE_GPR(cr, nullptr, dwarf_cr, dwarf_cr, LLDB_REGNUM_GENERIC_FLAGS,
 190                LLDB_INVALID_REGNUM),
 191     DEFINE_GPR(xer, nullptr, dwarf_xer, dwarf_xer, LLDB_INVALID_REGNUM,
 192                LLDB_INVALID_REGNUM),
 193     DEFINE_GPR(ctr, nullptr, dwarf_ctr, dwarf_ctr, LLDB_INVALID_REGNUM,
 194                LLDB_INVALID_REGNUM),
 195     DEFINE_GPR(pc, nullptr, dwarf_pc, dwarf_pc, LLDB_REGNUM_GENERIC_PC,
 196                LLDB_INVALID_REGNUM),
 197     {nullptr,
 198      nullptr,
 199      8,
 200      0,
 201      eEncodingUint,
 202      eFormatHex,
 203      {dwarf_cfa, dwarf_cfa, LLDB_INVALID_REGNUM, LLDB_INVALID_REGNUM},
 204      nullptr,
 205      nullptr,
 206      nullptr,
 207      }};
 208
 209 static const uint32_t k_num_register_infos = std::size(g_register_infos);
 210
 211 const lldb_private::RegisterInfo *
 212 ABISysV_ppc::GetRegisterInfoArray(uint32_t &count) {
 213   count = k_num_register_infos;
 214   return g_register_infos;
 215 }
 216
 217 size_t ABISysV_ppc::GetRedZoneSize() const { return 224; }
 218
 219 // Static Functions
 220
 221 ABISP
 222 ABISysV_ppc::CreateInstance(lldb::ProcessSP process_sp, const ArchSpec &arch) {
 223   if (arch.GetTriple().getArch() == llvm::Triple::ppc) {
 224     return ABISP(
 225         new ABISysV_ppc(std::move(process_sp), MakeMCRegisterInfo(arch)));
 226   }
 227   return ABISP();
 228 }
 229
 230 bool ABISysV_ppc::PrepareTrivialCall(Thread &thread, addr_t sp,
 231                                      addr_t func_addr, addr_t return_addr,
 232                                      llvm::ArrayRef<addr_t> args) const {
 233   Log *log = GetLog(LLDBLog::Expressions);
 234
 235   if (log) {
 236     StreamString s;
 237     s.Printf("ABISysV_ppc::PrepareTrivialCall (tid = 0x%" PRIx64
 238              ", sp = 0x%" PRIx64 ", func_addr = 0x%" PRIx64
 239              ", return_addr = 0x%" PRIx64,
 240              thread.GetID(), (uint64_t)sp, (uint64_t)func_addr,
 241              (uint64_t)return_addr);
 242
 243     for (size_t i = 0; i < args.size(); ++i)
 244       s.Printf(", arg%" PRIu64 " = 0x%" PRIx64, static_cast<uint64_t>(i + 1),
 245                args[i]);
 246     s.PutCString(")");
 247     log->PutString(s.GetString());
 248   }
 249
 250   RegisterContext *reg_ctx = thread.GetRegisterContext().get();
 251   if (!reg_ctx)
 252     return false;
 253
 254   const RegisterInfo *reg_info = nullptr;
 255
 256   if (args.size() > 8) // TODO handle more than 8 arguments
 257     return false;
 258
 259   for (size_t i = 0; i < args.size(); ++i) {
 260     reg_info = reg_ctx->GetRegisterInfo(eRegisterKindGeneric,
 261                                         LLDB_REGNUM_GENERIC_ARG1 + i);
 262     LLDB_LOGF(log, "About to write arg%" PRIu64 " (0x%" PRIx64 ") into %s",
 263               static_cast<uint64_t>(i + 1), args[i], reg_info->name);
 264     if (!reg_ctx->WriteRegisterFromUnsigned(reg_info, args[i]))
 265       return false;
 266   }
 267
 268   // First, align the SP
 269
 270   LLDB_LOGF(log, "16-byte aligning SP: 0x%" PRIx64 " to 0x%" PRIx64,
 271             (uint64_t)sp, (uint64_t)(sp & ~0xfull));
 272
 273   sp &= ~(0xfull); // 16-byte alignment
 274
 275   sp -= 8;
 276
 277   Status error;
 278   const RegisterInfo *pc_reg_info =
 279       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);
 280   const RegisterInfo *sp_reg_info =
 281       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);
 282   ProcessSP process_sp(thread.GetProcess());
 283
 284   RegisterValue reg_value;
 285
 286   LLDB_LOGF(log,
 287             "Pushing the return address onto the stack: 0x%" PRIx64
 288             ": 0x%" PRIx64,
 289             (uint64_t)sp, (uint64_t)return_addr);
 290
 291   // Save return address onto the stack
 292   if (!process_sp->WritePointerToMemory(sp, return_addr, error))
 293     return false;
 294
 295   // %r1 is set to the actual stack value.
 296
 297   LLDB_LOGF(log, "Writing SP: 0x%" PRIx64, (uint64_t)sp);
 298
 299   if (!reg_ctx->WriteRegisterFromUnsigned(sp_reg_info, sp))
 300     return false;
 301
 302   // %pc is set to the address of the called function.
 303
 304   LLDB_LOGF(log, "Writing IP: 0x%" PRIx64, (uint64_t)func_addr);
 305
 306   if (!reg_ctx->WriteRegisterFromUnsigned(pc_reg_info, func_addr))
 307     return false;
 308
 309   return true;
 310 }
 311
 312 static bool ReadIntegerArgument(Scalar &scalar, unsigned int bit_width,
 313                                 bool is_signed, Thread &thread,
 314                                 uint32_t *argument_register_ids,
 315                                 unsigned int &current_argument_register,
 316                                 addr_t &current_stack_argument) {
 317   if (bit_width > 64)
 318     return false; // Scalar can't hold large integer arguments
 319
 320   if (current_argument_register < 6) {
 321     scalar = thread.GetRegisterContext()->ReadRegisterAsUnsigned(
 322         argument_register_ids[current_argument_register], 0);
 323     current_argument_register++;
 324     if (is_signed)
 325       scalar.SignExtend(bit_width);
 326   } else {
 327     uint32_t byte_size = (bit_width + (8 - 1)) / 8;
 328     Status error;
 329     if (thread.GetProcess()->ReadScalarIntegerFromMemory(
 330             current_stack_argument, byte_size, is_signed, scalar, error)) {
 331       current_stack_argument += byte_size;
 332       return true;
 333     }
 334     return false;
 335   }
 336   return true;
 337 }
 338
 339 bool ABISysV_ppc::GetArgumentValues(Thread &thread, ValueList &values) const {
 340   unsigned int num_values = values.GetSize();
 341   unsigned int value_index;
 342
 343   // Extract the register context so we can read arguments from registers
 344
 345   RegisterContext *reg_ctx = thread.GetRegisterContext().get();
 346
 347   if (!reg_ctx)
 348     return false;
 349
 350   // Get the pointer to the first stack argument so we have a place to start
 351   // when reading data
 352
 353   addr_t sp = reg_ctx->GetSP(0);
 354
 355   if (!sp)
 356     return false;
 357
 358   addr_t current_stack_argument = sp + 48; // jump over return address
 359
 360   uint32_t argument_register_ids[8];
 361
 362   argument_register_ids[0] =
 363       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1)
 364           ->kinds[eRegisterKindLLDB];
 365   argument_register_ids[1] =
 366       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG2)
 367           ->kinds[eRegisterKindLLDB];
 368   argument_register_ids[2] =
 369       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG3)
 370           ->kinds[eRegisterKindLLDB];
 371   argument_register_ids[3] =
 372       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG4)
 373           ->kinds[eRegisterKindLLDB];
 374   argument_register_ids[4] =
 375       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG5)
 376           ->kinds[eRegisterKindLLDB];
 377   argument_register_ids[5] =
 378       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG6)
 379           ->kinds[eRegisterKindLLDB];
 380   argument_register_ids[6] =
 381       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG7)
 382           ->kinds[eRegisterKindLLDB];
 383   argument_register_ids[7] =
 384       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG8)
 385           ->kinds[eRegisterKindLLDB];
 386
 387   unsigned int current_argument_register = 0;
 388
 389   for (value_index = 0; value_index < num_values; ++value_index) {
 390     Value *value = values.GetValueAtIndex(value_index);
 391
 392     if (!value)
 393       return false;
 394
 395     // We currently only support extracting values with Clang QualTypes. Do we
 396     // care about others?
 397     CompilerType compiler_type = value->GetCompilerType();
 398     std::optional<uint64_t> bit_size = compiler_type.GetBitSize(&thread);
 399     if (!bit_size)
 400       return false;
 401     bool is_signed;
 402     if (compiler_type.IsIntegerOrEnumerationType(is_signed))
 403       ReadIntegerArgument(value->GetScalar(), *bit_size, is_signed, thread,
 404                           argument_register_ids, current_argument_register,
 405                           current_stack_argument);
 406     else if (compiler_type.IsPointerType())
 407       ReadIntegerArgument(value->GetScalar(), *bit_size, false, thread,
 408                           argument_register_ids, current_argument_register,
 409                           current_stack_argument);
 410   }
 411
 412   return true;
 413 }
 414
 415 Status ABISysV_ppc::SetReturnValueObject(lldb::StackFrameSP &frame_sp,
 416                                          lldb::ValueObjectSP &new_value_sp) {
 417   Status error;
 418   if (!new_value_sp) {
 419     error.SetErrorString("Empty value object for return value.");
 420     return error;
 421   }
 422
 423   CompilerType compiler_type = new_value_sp->GetCompilerType();
 424   if (!compiler_type) {
 425     error.SetErrorString("Null clang type for return value.");
 426     return error;
 427   }
 428
 429   Thread *thread = frame_sp->GetThread().get();
 430
 431   bool is_signed;
 432   uint32_t count;
 433   bool is_complex;
 434
 435   RegisterContext *reg_ctx = thread->GetRegisterContext().get();
 436
 437   bool set_it_simple = false;
 438   if (compiler_type.IsIntegerOrEnumerationType(is_signed) ||
 439       compiler_type.IsPointerType()) {
 440     const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoByName("r3", 0);
 441
 442     DataExtractor data;
 443     Status data_error;
 444     size_t num_bytes = new_value_sp->GetData(data, data_error);
 445     if (data_error.Fail()) {
 446       error.SetErrorStringWithFormat(
 447           "Couldn't convert return value to raw data: %s",
 448           data_error.AsCString());
 449       return error;
 450     }
 451     lldb::offset_t offset = 0;
 452     if (num_bytes <= 8) {
 453       uint64_t raw_value = data.GetMaxU64(&offset, num_bytes);
 454
 455       if (reg_ctx->WriteRegisterFromUnsigned(reg_info, raw_value))
 456         set_it_simple = true;
 457     } else {
 458       error.SetErrorString("We don't support returning longer than 64 bit "
 459                            "integer values at present.");
 460     }
 461   } else if (compiler_type.IsFloatingPointType(count, is_complex)) {
 462     if (is_complex)
 463       error.SetErrorString(
 464           "We don't support returning complex values at present");
 465     else {
 466       std::optional<uint64_t> bit_width =
 467           compiler_type.GetBitSize(frame_sp.get());
 468       if (!bit_width) {
 469         error.SetErrorString("can't get type size");
 470         return error;
 471       }
 472       if (*bit_width <= 64) {
 473         DataExtractor data;
 474         Status data_error;
 475         size_t num_bytes = new_value_sp->GetData(data, data_error);
 476         if (data_error.Fail()) {
 477           error.SetErrorStringWithFormat(
 478               "Couldn't convert return value to raw data: %s",
 479               data_error.AsCString());
 480           return error;
 481         }
 482
 483         unsigned char buffer[16];
 484         ByteOrder byte_order = data.GetByteOrder();
 485
 486         data.CopyByteOrderedData(0, num_bytes, buffer, 16, byte_order);
 487         set_it_simple = true;
 488       } else {
 489         // FIXME - don't know how to do 80 bit long doubles yet.
 490         error.SetErrorString(
 491             "We don't support returning float values > 64 bits at present");
 492       }
 493     }
 494   }
 495
 496   if (!set_it_simple) {
 497     // Okay we've got a structure or something that doesn't fit in a simple
 498     // register. We should figure out where it really goes, but we don't
 499     // support this yet.
 500     error.SetErrorString("We only support setting simple integer and float "
 501                          "return types at present.");
 502   }
 503
 504   return error;
 505 }
 506
 507 ValueObjectSP ABISysV_ppc::GetReturnValueObjectSimple(
 508     Thread &thread, CompilerType &return_compiler_type) const {
 509   ValueObjectSP return_valobj_sp;
 510   Value value;
 511
 512   if (!return_compiler_type)
 513     return return_valobj_sp;
 514
 515   // value.SetContext (Value::eContextTypeClangType, return_value_type);
 516   value.SetCompilerType(return_compiler_type);
 517
 518   RegisterContext *reg_ctx = thread.GetRegisterContext().get();
 519   if (!reg_ctx)
 520     return return_valobj_sp;
 521
 522   const uint32_t type_flags = return_compiler_type.GetTypeInfo();
 523   if (type_flags & eTypeIsScalar) {
 524     value.SetValueType(Value::ValueType::Scalar);
 525
 526     bool success = false;
 527     if (type_flags & eTypeIsInteger) {
 528       // Extract the register context so we can read arguments from registers
 529
 530       std::optional<uint64_t> byte_size =
 531           return_compiler_type.GetByteSize(&thread);
 532       if (!byte_size)
 533         return return_valobj_sp;
 534       uint64_t raw_value = thread.GetRegisterContext()->ReadRegisterAsUnsigned(
 535           reg_ctx->GetRegisterInfoByName("r3", 0), 0);
 536       const bool is_signed = (type_flags & eTypeIsSigned) != 0;
 537       switch (*byte_size) {
 538       default:
 539         break;
 540
 541       case sizeof(uint64_t):
 542         if (is_signed)
 543           value.GetScalar() = (int64_t)(raw_value);
 544         else
 545           value.GetScalar() = (uint64_t)(raw_value);
 546         success = true;
 547         break;
 548
 549       case sizeof(uint32_t):
 550         if (is_signed)
 551           value.GetScalar() = (int32_t)(raw_value & UINT32_MAX);
 552         else
 553           value.GetScalar() = (uint32_t)(raw_value & UINT32_MAX);
 554         success = true;
 555         break;
 556
 557       case sizeof(uint16_t):
 558         if (is_signed)
 559           value.GetScalar() = (int16_t)(raw_value & UINT16_MAX);
 560         else
 561           value.GetScalar() = (uint16_t)(raw_value & UINT16_MAX);
 562         success = true;
 563         break;
 564
 565       case sizeof(uint8_t):
 566         if (is_signed)
 567           value.GetScalar() = (int8_t)(raw_value & UINT8_MAX);
 568         else
 569           value.GetScalar() = (uint8_t)(raw_value & UINT8_MAX);
 570         success = true;
 571         break;
 572       }
 573     } else if (type_flags & eTypeIsFloat) {
 574       if (type_flags & eTypeIsComplex) {
 575         // Don't handle complex yet.
 576       } else {
 577         std::optional<uint64_t> byte_size =
 578             return_compiler_type.GetByteSize(&thread);
 579         if (byte_size && *byte_size <= sizeof(long double)) {
 580           const RegisterInfo *f1_info = reg_ctx->GetRegisterInfoByName("f1", 0);
 581           RegisterValue f1_value;
 582           if (reg_ctx->ReadRegister(f1_info, f1_value)) {
 583             DataExtractor data;
 584             if (f1_value.GetData(data)) {
 585               lldb::offset_t offset = 0;
 586               if (*byte_size == sizeof(float)) {
 587                 value.GetScalar() = (float)data.GetFloat(&offset);
 588                 success = true;
 589               } else if (*byte_size == sizeof(double)) {
 590                 value.GetScalar() = (double)data.GetDouble(&offset);
 591                 success = true;
 592               }
 593             }
 594           }
 595         }
 596       }
 597     }
 598
 599     if (success)
 600       return_valobj_sp = ValueObjectConstResult::Create(
 601           thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));
 602   } else if (type_flags & eTypeIsPointer) {
 603     unsigned r3_id =
 604         reg_ctx->GetRegisterInfoByName("r3", 0)->kinds[eRegisterKindLLDB];
 605     value.GetScalar() =
 606         (uint64_t)thread.GetRegisterContext()->ReadRegisterAsUnsigned(r3_id, 0);
 607     value.SetValueType(Value::ValueType::Scalar);
 608     return_valobj_sp = ValueObjectConstResult::Create(
 609         thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));
 610   } else if (type_flags & eTypeIsVector) {
 611     std::optional<uint64_t> byte_size =
 612         return_compiler_type.GetByteSize(&thread);
 613     if (byte_size && *byte_size > 0) {
 614       const RegisterInfo *altivec_reg = reg_ctx->GetRegisterInfoByName("v2", 0);
 615       if (altivec_reg) {
 616         if (*byte_size <= altivec_reg->byte_size) {
 617           ProcessSP process_sp(thread.GetProcess());
 618           if (process_sp) {
 619             std::unique_ptr<DataBufferHeap> heap_data_up(
 620                 new DataBufferHeap(*byte_size, 0));
 621             const ByteOrder byte_order = process_sp->GetByteOrder();
 622             RegisterValue reg_value;
 623             if (reg_ctx->ReadRegister(altivec_reg, reg_value)) {
 624               Status error;
 625               if (reg_value.GetAsMemoryData(
 626                       *altivec_reg, heap_data_up->GetBytes(),
 627                       heap_data_up->GetByteSize(), byte_order, error)) {
 628                 DataExtractor data(DataBufferSP(heap_data_up.release()),
 629                                    byte_order,
 630                                    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   std::optional<uint64_t> bit_width = return_compiler_type.GetBitSize(&thread);
 663   if (!bit_width)
 664     return return_valobj_sp;
 665   if (return_compiler_type.IsAggregateType()) {
 666     Target *target = exe_ctx.GetTargetPtr();
 667     bool is_memory = true;
 668     if (*bit_width <= 128) {
 669       ByteOrder target_byte_order = target->GetArchitecture().GetByteOrder();
 670       WritableDataBufferSP data_sp(new DataBufferHeap(16, 0));
 671       DataExtractor return_ext(data_sp, target_byte_order,
 672                                target->GetArchitecture().GetAddressByteSize());
 673
 674       const RegisterInfo *r3_info = reg_ctx_sp->GetRegisterInfoByName("r3", 0);
 675       const RegisterInfo *rdx_info =
 676           reg_ctx_sp->GetRegisterInfoByName("rdx", 0);
 677
 678       RegisterValue r3_value, rdx_value;
 679       reg_ctx_sp->ReadRegister(r3_info, r3_value);
 680       reg_ctx_sp->ReadRegister(rdx_info, rdx_value);
 681
 682       DataExtractor r3_data, rdx_data;
 683
 684       r3_value.GetData(r3_data);
 685       rdx_value.GetData(rdx_data);
 686
 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         std::optional<uint64_t> field_bit_width =
 705             field_compiler_type.GetBitSize(&thread);
 706         if (!field_bit_width)
 707           return return_valobj_sp;
 708
 709         // If there are any unaligned fields, this is stored in memory.
 710         if (field_bit_offset % *field_bit_width != 0) {
 711           is_memory = true;
 712           break;
 713         }
 714
 715         uint32_t field_byte_width = *field_bit_width / 8;
 716         uint32_t field_byte_offset = field_bit_offset / 8;
 717
 718         DataExtractor *copy_from_extractor = nullptr;
 719         uint32_t copy_from_offset = 0;
 720
 721         if (field_compiler_type.IsIntegerOrEnumerationType(is_signed) ||
 722             field_compiler_type.IsPointerType()) {
 723           if (integer_bytes < 8) {
 724             if (integer_bytes + field_byte_width <= 8) {
 725               // This is in RAX, copy from register to our result structure:
 726               copy_from_extractor = &r3_data;
 727               copy_from_offset = integer_bytes;
 728               integer_bytes += field_byte_width;
 729             } else {
 730               // The next field wouldn't fit in the remaining space, so we
 731               // pushed it to rdx.
 732               copy_from_extractor = &rdx_data;
 733               copy_from_offset = 0;
 734               integer_bytes = 8 + field_byte_width;
 735             }
 736           } else if (integer_bytes + field_byte_width <= 16) {
 737             copy_from_extractor = &rdx_data;
 738             copy_from_offset = integer_bytes - 8;
 739             integer_bytes += field_byte_width;
 740           } else {
 741             // The last field didn't fit.  I can't see how that would happen
 742             // w/o the overall size being greater than 16 bytes.  For now,
 743             // return a nullptr return value object.
 744             return return_valobj_sp;
 745           }
 746         } else if (field_compiler_type.IsFloatingPointType(count, is_complex)) {
 747           // Structs with long doubles are always passed in memory.
 748           if (*field_bit_width == 128) {
 749             is_memory = true;
 750             break;
 751           } else if (*field_bit_width == 64) {
 752             copy_from_offset = 0;
 753           } else if (*field_bit_width == 32) {
 754             // This one is kind of complicated.  If we are in an "eightbyte"
 755             // with another float, we'll be stuffed into an xmm register with
 756             // it.  If we are in an "eightbyte" with one or more ints, then we
 757             // will be stuffed into the appropriate GPR with them.
 758             bool in_gpr;
 759             if (field_byte_offset % 8 == 0) {
 760               // We are at the beginning of one of the eightbytes, so check the
 761               // next element (if any)
 762               if (idx == num_children - 1)
 763                 in_gpr = false;
 764               else {
 765                 uint64_t next_field_bit_offset = 0;
 766                 CompilerType next_field_compiler_type =
 767                     return_compiler_type.GetFieldAtIndex(idx + 1, name,
 768                                                          &next_field_bit_offset,
 769                                                          nullptr, nullptr);
 770                 if (next_field_compiler_type.IsIntegerOrEnumerationType(
 771                         is_signed))
 772                   in_gpr = true;
 773                 else {
 774                   copy_from_offset = 0;
 775                   in_gpr = false;
 776                 }
 777               }
 778             } else if (field_byte_offset % 4 == 0) {
 779               // We are inside of an eightbyte, so see if the field before us
 780               // is floating point: This could happen if somebody put padding
 781               // in the structure.
 782               if (idx == 0)
 783                 in_gpr = false;
 784               else {
 785                 uint64_t prev_field_bit_offset = 0;
 786                 CompilerType prev_field_compiler_type =
 787                     return_compiler_type.GetFieldAtIndex(idx - 1, name,
 788                                                          &prev_field_bit_offset,
 789                                                          nullptr, nullptr);
 790                 if (prev_field_compiler_type.IsIntegerOrEnumerationType(
 791                         is_signed))
 792                   in_gpr = true;
 793                 else {
 794                   copy_from_offset = 4;
 795                   in_gpr = false;
 796                 }
 797               }
 798             } else {
 799               is_memory = true;
 800               continue;
 801             }
 802
 803             // Okay, we've figured out whether we are in GPR or XMM, now figure
 804             // out which one.
 805             if (in_gpr) {
 806               if (integer_bytes < 8) {
 807                 // This is in RAX, copy from register to our result structure:
 808                 copy_from_extractor = &r3_data;
 809                 copy_from_offset = integer_bytes;
 810                 integer_bytes += field_byte_width;
 811               } else {
 812                 copy_from_extractor = &rdx_data;
 813                 copy_from_offset = integer_bytes - 8;
 814                 integer_bytes += field_byte_width;
 815               }
 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->SetUnspecifiedRegistersAreUndefined(true);
 900   row->GetCFAValue().SetIsRegisterDereferenced(sp_reg_num);
 901
 902   row->SetRegisterLocationToAtCFAPlusOffset(pc_reg_num, ptr_size * 1, true);
 903   row->SetRegisterLocationToIsCFAPlusOffset(sp_reg_num, 0, true);
 904
 905   unwind_plan.AppendRow(row);
 906   unwind_plan.SetSourceName("ppc default unwind plan");
 907   unwind_plan.SetSourcedFromCompiler(eLazyBoolNo);
 908   unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo);
 909   unwind_plan.SetUnwindPlanForSignalTrap(eLazyBoolNo);
 910   unwind_plan.SetReturnAddressRegister(dwarf_lr);
 911   return true;
 912 }
 913
 914 bool ABISysV_ppc::RegisterIsVolatile(const RegisterInfo *reg_info) {
 915   return !RegisterIsCalleeSaved(reg_info);
 916 }
 917
 918 // See "Register Usage" in the
 919 // "System V Application Binary Interface"
 920 // "64-bit PowerPC ELF Application Binary Interface Supplement" current version
 921 // is 1.9 released 2004 at http://refspecs.linuxfoundation.org/ELF/ppc/PPC-
 922 // elf64abi-1.9.pdf
 923
 924 bool ABISysV_ppc::RegisterIsCalleeSaved(const RegisterInfo *reg_info) {
 925   if (reg_info) {
 926     // Preserved registers are :
 927     //    r1,r2,r13-r31
 928     //    f14-f31 (not yet)
 929     //    v20-v31 (not yet)
 930     //    vrsave (not yet)
 931
 932     const char *name = reg_info->name;
 933     if (name[0] == 'r') {
 934       if ((name[1] == '1' || name[1] == '2') && name[2] == '\0')
 935         return true;
 936       if (name[1] == '1' && name[2] > '2')
 937         return true;
 938       if ((name[1] == '2' || name[1] == '3') && name[2] != '\0')
 939         return true;
 940     }
 941
 942     if (name[0] == 'f' && name[1] >= '0' && name[1] <= '9') {
 943       if (name[3] == '1' && name[4] >= '4')
 944         return true;
 945       if ((name[3] == '2' || name[3] == '3') && name[4] != '\0')
 946         return true;
 947     }
 948
 949     if (name[0] == 's' && name[1] == 'p' && name[2] == '\0') // sp
 950       return true;
 951     if (name[0] == 'f' && name[1] == 'p' && name[2] == '\0') // fp
 952       return true;
 953     if (name[0] == 'p' && name[1] == 'c' && name[2] == '\0') // pc
 954       return true;
 955   }
 956   return false;
 957 }
 958
 959 void ABISysV_ppc::Initialize() {
 960   PluginManager::RegisterPlugin(GetPluginNameStatic(),
 961                                 "System V ABI for ppc targets", CreateInstance);
 962 }
 963
 964 void ABISysV_ppc::Terminate() {
 965   PluginManager::UnregisterPlugin(CreateInstance);
 966 }