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/ConstString.h"
  20 #include "lldb/Core/DataExtractor.h"
  21 #include "lldb/Core/Error.h"
  22 #include "lldb/Core/Log.h"
  23 #include "lldb/Core/Module.h"
  24 #include "lldb/Core/PluginManager.h"
  25 #include "lldb/Core/RegisterValue.h"
  26 #include "lldb/Core/Value.h"
  27 #include "lldb/Core/ValueObjectConstResult.h"
  28 #include "lldb/Core/ValueObjectMemory.h"
  29 #include "lldb/Core/ValueObjectRegister.h"
  30 #include "lldb/Symbol/UnwindPlan.h"
  31 #include "lldb/Target/Process.h"
  32 #include "lldb/Target/RegisterContext.h"
  33 #include "lldb/Target/StackFrame.h"
  34 #include "lldb/Target/Target.h"
  35 #include "lldb/Target/Thread.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(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);
 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   Error 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 0
 295     // This code adds an extra frame so that we don't lose the function that we came from
 296     // by pushing the PC and the FP and then writing the current FP to point to the FP value
 297     // we just pushed. It is disabled for now until the stack backtracing code can be debugged.
 298
 299     // Save current PC
 300     const RegisterInfo *fp_reg_info = reg_ctx->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_FP);
 301     if (reg_ctx->ReadRegister(pc_reg_info, reg_value))
 302     {
 303         if (log)
 304             log->Printf("Pushing the current PC onto the stack: 0x%" PRIx64 ": 0x%" PRIx64, (uint64_t)sp, reg_value.GetAsUInt64());
 305
 306         if (!process_sp->WritePointerToMemory(sp, reg_value.GetAsUInt64(), error))
 307             return false;
 308
 309         sp -= 8;
 310
 311         // Save current FP
 312         if (reg_ctx->ReadRegister(fp_reg_info, reg_value))
 313         {
 314             if (log)
 315                 log->Printf("Pushing the current FP onto the stack: 0x%" PRIx64 ": 0x%" PRIx64, (uint64_t)sp, reg_value.GetAsUInt64());
 316
 317             if (!process_sp->WritePointerToMemory(sp, reg_value.GetAsUInt64(), error))
 318                 return false;
 319         }
 320         // Setup FP backchain
 321         reg_value.SetUInt64 (sp);
 322
 323         if (log)
 324             log->Printf("Writing FP:  0x%" PRIx64 " (for FP backchain)", reg_value.GetAsUInt64());
 325
 326         if (!reg_ctx->WriteRegister(fp_reg_info, reg_value))
 327         {
 328             return false;
 329         }
 330
 331         sp -= 8;
 332     }
 333 #endif
 334
 335   if (log)
 336     log->Printf("Pushing the return address onto the stack: 0x%" PRIx64
 337                 ": 0x%" PRIx64,
 338                 (uint64_t)sp, (uint64_t)return_addr);
 339
 340   // Save return address onto the stack
 341   if (!process_sp->WritePointerToMemory(sp, return_addr, error))
 342     return false;
 343
 344   // %r1 is set to the actual stack value.
 345
 346   if (log)
 347     log->Printf("Writing SP: 0x%" PRIx64, (uint64_t)sp);
 348
 349   if (!reg_ctx->WriteRegisterFromUnsigned(sp_reg_info, sp))
 350     return false;
 351
 352   // %pc is set to the address of the called function.
 353
 354   if (log)
 355     log->Printf("Writing IP: 0x%" PRIx64, (uint64_t)func_addr);
 356
 357   if (!reg_ctx->WriteRegisterFromUnsigned(pc_reg_info, func_addr))
 358     return false;
 359
 360   return true;
 361 }
 362
 363 static bool ReadIntegerArgument(Scalar &scalar, unsigned int bit_width,
 364                                 bool is_signed, Thread &thread,
 365                                 uint32_t *argument_register_ids,
 366                                 unsigned int &current_argument_register,
 367                                 addr_t &current_stack_argument) {
 368   if (bit_width > 64)
 369     return false; // Scalar can't hold large integer arguments
 370
 371   if (current_argument_register < 6) {
 372     scalar = thread.GetRegisterContext()->ReadRegisterAsUnsigned(
 373         argument_register_ids[current_argument_register], 0);
 374     current_argument_register++;
 375     if (is_signed)
 376       scalar.SignExtend(bit_width);
 377   } else {
 378     uint32_t byte_size = (bit_width + (8 - 1)) / 8;
 379     Error error;
 380     if (thread.GetProcess()->ReadScalarIntegerFromMemory(
 381             current_stack_argument, byte_size, is_signed, scalar, error)) {
 382       current_stack_argument += byte_size;
 383       return true;
 384     }
 385     return false;
 386   }
 387   return true;
 388 }
 389
 390 bool ABISysV_ppc::GetArgumentValues(Thread &thread, ValueList &values) const {
 391   unsigned int num_values = values.GetSize();
 392   unsigned int value_index;
 393
 394   // Extract the register context so we can read arguments from registers
 395
 396   RegisterContext *reg_ctx = thread.GetRegisterContext().get();
 397
 398   if (!reg_ctx)
 399     return false;
 400
 401   // Get the pointer to the first stack argument so we have a place to start
 402   // when reading data
 403
 404   addr_t sp = reg_ctx->GetSP(0);
 405
 406   if (!sp)
 407     return false;
 408
 409   addr_t current_stack_argument = sp + 48; // jump over return address
 410
 411   uint32_t argument_register_ids[8];
 412
 413   argument_register_ids[0] =
 414       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1)
 415           ->kinds[eRegisterKindLLDB];
 416   argument_register_ids[1] =
 417       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG2)
 418           ->kinds[eRegisterKindLLDB];
 419   argument_register_ids[2] =
 420       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG3)
 421           ->kinds[eRegisterKindLLDB];
 422   argument_register_ids[3] =
 423       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG4)
 424           ->kinds[eRegisterKindLLDB];
 425   argument_register_ids[4] =
 426       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG5)
 427           ->kinds[eRegisterKindLLDB];
 428   argument_register_ids[5] =
 429       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG6)
 430           ->kinds[eRegisterKindLLDB];
 431   argument_register_ids[6] =
 432       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG7)
 433           ->kinds[eRegisterKindLLDB];
 434   argument_register_ids[7] =
 435       reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG8)
 436           ->kinds[eRegisterKindLLDB];
 437
 438   unsigned int current_argument_register = 0;
 439
 440   for (value_index = 0; value_index < num_values; ++value_index) {
 441     Value *value = values.GetValueAtIndex(value_index);
 442
 443     if (!value)
 444       return false;
 445
 446     // We currently only support extracting values with Clang QualTypes.
 447     // Do we care about others?
 448     CompilerType compiler_type = value->GetCompilerType();
 449     if (!compiler_type)
 450       return false;
 451     bool is_signed;
 452
 453     if (compiler_type.IsIntegerOrEnumerationType(is_signed)) {
 454       ReadIntegerArgument(value->GetScalar(), compiler_type.GetBitSize(&thread),
 455                           is_signed, thread, argument_register_ids,
 456                           current_argument_register, current_stack_argument);
 457     } else if (compiler_type.IsPointerType()) {
 458       ReadIntegerArgument(value->GetScalar(), compiler_type.GetBitSize(&thread),
 459                           false, thread, argument_register_ids,
 460                           current_argument_register, current_stack_argument);
 461     }
 462   }
 463
 464   return true;
 465 }
 466
 467 Error ABISysV_ppc::SetReturnValueObject(lldb::StackFrameSP &frame_sp,
 468                                         lldb::ValueObjectSP &new_value_sp) {
 469   Error error;
 470   if (!new_value_sp) {
 471     error.SetErrorString("Empty value object for return value.");
 472     return error;
 473   }
 474
 475   CompilerType compiler_type = new_value_sp->GetCompilerType();
 476   if (!compiler_type) {
 477     error.SetErrorString("Null clang type for return value.");
 478     return error;
 479   }
 480
 481   Thread *thread = frame_sp->GetThread().get();
 482
 483   bool is_signed;
 484   uint32_t count;
 485   bool is_complex;
 486
 487   RegisterContext *reg_ctx = thread->GetRegisterContext().get();
 488
 489   bool set_it_simple = false;
 490   if (compiler_type.IsIntegerOrEnumerationType(is_signed) ||
 491       compiler_type.IsPointerType()) {
 492     const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoByName("r3", 0);
 493
 494     DataExtractor data;
 495     Error data_error;
 496     size_t num_bytes = new_value_sp->GetData(data, data_error);
 497     if (data_error.Fail()) {
 498       error.SetErrorStringWithFormat(
 499           "Couldn't convert return value to raw data: %s",
 500           data_error.AsCString());
 501       return error;
 502     }
 503     lldb::offset_t offset = 0;
 504     if (num_bytes <= 8) {
 505       uint64_t raw_value = data.GetMaxU64(&offset, num_bytes);
 506
 507       if (reg_ctx->WriteRegisterFromUnsigned(reg_info, raw_value))
 508         set_it_simple = true;
 509     } else {
 510       error.SetErrorString("We don't support returning longer than 64 bit "
 511                            "integer values at present.");
 512     }
 513   } else if (compiler_type.IsFloatingPointType(count, is_complex)) {
 514     if (is_complex)
 515       error.SetErrorString(
 516           "We don't support returning complex values at present");
 517     else {
 518       size_t bit_width = compiler_type.GetBitSize(frame_sp.get());
 519       if (bit_width <= 64) {
 520         DataExtractor data;
 521         Error data_error;
 522         size_t num_bytes = new_value_sp->GetData(data, data_error);
 523         if (data_error.Fail()) {
 524           error.SetErrorStringWithFormat(
 525               "Couldn't convert return value to raw data: %s",
 526               data_error.AsCString());
 527           return error;
 528         }
 529
 530         unsigned char buffer[16];
 531         ByteOrder byte_order = data.GetByteOrder();
 532
 533         data.CopyByteOrderedData(0, num_bytes, buffer, 16, byte_order);
 534         set_it_simple = true;
 535       } else {
 536         // FIXME - don't know how to do 80 bit long doubles yet.
 537         error.SetErrorString(
 538             "We don't support returning float values > 64 bits at present");
 539       }
 540     }
 541   }
 542
 543   if (!set_it_simple) {
 544     // Okay we've got a structure or something that doesn't fit in a simple
 545     // register.
 546     // We should figure out where it really goes, but we don't support this yet.
 547     error.SetErrorString("We only support setting simple integer and float "
 548                          "return types at present.");
 549   }
 550
 551   return error;
 552 }
 553
 554 ValueObjectSP ABISysV_ppc::GetReturnValueObjectSimple(
 555     Thread &thread, CompilerType &return_compiler_type) const {
 556   ValueObjectSP return_valobj_sp;
 557   Value value;
 558
 559   if (!return_compiler_type)
 560     return return_valobj_sp;
 561
 562   // value.SetContext (Value::eContextTypeClangType, return_value_type);
 563   value.SetCompilerType(return_compiler_type);
 564
 565   RegisterContext *reg_ctx = thread.GetRegisterContext().get();
 566   if (!reg_ctx)
 567     return return_valobj_sp;
 568
 569   const uint32_t type_flags = return_compiler_type.GetTypeInfo();
 570   if (type_flags & eTypeIsScalar) {
 571     value.SetValueType(Value::eValueTypeScalar);
 572
 573     bool success = false;
 574     if (type_flags & eTypeIsInteger) {
 575       // Extract the register context so we can read arguments from registers
 576
 577       const size_t byte_size = return_compiler_type.GetByteSize(nullptr);
 578       uint64_t raw_value = thread.GetRegisterContext()->ReadRegisterAsUnsigned(
 579           reg_ctx->GetRegisterInfoByName("r3", 0), 0);
 580       const bool is_signed = (type_flags & eTypeIsSigned) != 0;
 581       switch (byte_size) {
 582       default:
 583         break;
 584
 585       case sizeof(uint64_t):
 586         if (is_signed)
 587           value.GetScalar() = (int64_t)(raw_value);
 588         else
 589           value.GetScalar() = (uint64_t)(raw_value);
 590         success = true;
 591         break;
 592
 593       case sizeof(uint32_t):
 594         if (is_signed)
 595           value.GetScalar() = (int32_t)(raw_value & UINT32_MAX);
 596         else
 597           value.GetScalar() = (uint32_t)(raw_value & UINT32_MAX);
 598         success = true;
 599         break;
 600
 601       case sizeof(uint16_t):
 602         if (is_signed)
 603           value.GetScalar() = (int16_t)(raw_value & UINT16_MAX);
 604         else
 605           value.GetScalar() = (uint16_t)(raw_value & UINT16_MAX);
 606         success = true;
 607         break;
 608
 609       case sizeof(uint8_t):
 610         if (is_signed)
 611           value.GetScalar() = (int8_t)(raw_value & UINT8_MAX);
 612         else
 613           value.GetScalar() = (uint8_t)(raw_value & UINT8_MAX);
 614         success = true;
 615         break;
 616       }
 617     } else if (type_flags & eTypeIsFloat) {
 618       if (type_flags & eTypeIsComplex) {
 619         // Don't handle complex yet.
 620       } else {
 621         const size_t byte_size = return_compiler_type.GetByteSize(nullptr);
 622         if (byte_size <= sizeof(long double)) {
 623           const RegisterInfo *f1_info = reg_ctx->GetRegisterInfoByName("f1", 0);
 624           RegisterValue f1_value;
 625           if (reg_ctx->ReadRegister(f1_info, f1_value)) {
 626             DataExtractor data;
 627             if (f1_value.GetData(data)) {
 628               lldb::offset_t offset = 0;
 629               if (byte_size == sizeof(float)) {
 630                 value.GetScalar() = (float)data.GetFloat(&offset);
 631                 success = true;
 632               } else if (byte_size == sizeof(double)) {
 633                 value.GetScalar() = (double)data.GetDouble(&offset);
 634                 success = true;
 635               }
 636             }
 637           }
 638         }
 639       }
 640     }
 641
 642     if (success)
 643       return_valobj_sp = ValueObjectConstResult::Create(
 644           thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));
 645   } else if (type_flags & eTypeIsPointer) {
 646     unsigned r3_id =
 647         reg_ctx->GetRegisterInfoByName("r3", 0)->kinds[eRegisterKindLLDB];
 648     value.GetScalar() =
 649         (uint64_t)thread.GetRegisterContext()->ReadRegisterAsUnsigned(r3_id, 0);
 650     value.SetValueType(Value::eValueTypeScalar);
 651     return_valobj_sp = ValueObjectConstResult::Create(
 652         thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));
 653   } else if (type_flags & eTypeIsVector) {
 654     const size_t byte_size = return_compiler_type.GetByteSize(nullptr);
 655     if (byte_size > 0) {
 656       const RegisterInfo *altivec_reg = reg_ctx->GetRegisterInfoByName("v2", 0);
 657       if (altivec_reg) {
 658         if (byte_size <= altivec_reg->byte_size) {
 659           ProcessSP process_sp(thread.GetProcess());
 660           if (process_sp) {
 661             std::unique_ptr<DataBufferHeap> heap_data_ap(
 662                 new DataBufferHeap(byte_size, 0));
 663             const ByteOrder byte_order = process_sp->GetByteOrder();
 664             RegisterValue reg_value;
 665             if (reg_ctx->ReadRegister(altivec_reg, reg_value)) {
 666               Error error;
 667               if (reg_value.GetAsMemoryData(
 668                       altivec_reg, heap_data_ap->GetBytes(),
 669                       heap_data_ap->GetByteSize(), byte_order, error)) {
 670                 DataExtractor data(DataBufferSP(heap_data_ap.release()),
 671                                    byte_order, process_sp->GetTarget()
 672                                                    .GetArchitecture()
 673                                                    .GetAddressByteSize());
 674                 return_valobj_sp = ValueObjectConstResult::Create(
 675                     &thread, return_compiler_type, ConstString(""), data);
 676               }
 677             }
 678           }
 679         }
 680       }
 681     }
 682   }
 683
 684   return return_valobj_sp;
 685 }
 686
 687 ValueObjectSP ABISysV_ppc::GetReturnValueObjectImpl(
 688     Thread &thread, CompilerType &return_compiler_type) const {
 689   ValueObjectSP return_valobj_sp;
 690
 691   if (!return_compiler_type)
 692     return return_valobj_sp;
 693
 694   ExecutionContext exe_ctx(thread.shared_from_this());
 695   return_valobj_sp = GetReturnValueObjectSimple(thread, return_compiler_type);
 696   if (return_valobj_sp)
 697     return return_valobj_sp;
 698
 699   RegisterContextSP reg_ctx_sp = thread.GetRegisterContext();
 700   if (!reg_ctx_sp)
 701     return return_valobj_sp;
 702
 703   const size_t bit_width = return_compiler_type.GetBitSize(&thread);
 704   if (return_compiler_type.IsAggregateType()) {
 705     Target *target = exe_ctx.GetTargetPtr();
 706     bool is_memory = true;
 707     if (bit_width <= 128) {
 708       ByteOrder target_byte_order = target->GetArchitecture().GetByteOrder();
 709       DataBufferSP data_sp(new DataBufferHeap(16, 0));
 710       DataExtractor return_ext(data_sp, target_byte_order,
 711                                target->GetArchitecture().GetAddressByteSize());
 712
 713       const RegisterInfo *r3_info = reg_ctx_sp->GetRegisterInfoByName("r3", 0);
 714       const RegisterInfo *rdx_info =
 715           reg_ctx_sp->GetRegisterInfoByName("rdx", 0);
 716
 717       RegisterValue r3_value, rdx_value;
 718       reg_ctx_sp->ReadRegister(r3_info, r3_value);
 719       reg_ctx_sp->ReadRegister(rdx_info, rdx_value);
 720
 721       DataExtractor r3_data, rdx_data;
 722
 723       r3_value.GetData(r3_data);
 724       rdx_value.GetData(rdx_data);
 725
 726       uint32_t fp_bytes =
 727           0; // Tracks how much of the xmm registers we've consumed so far
 728       uint32_t integer_bytes =
 729           0; // Tracks how much of the r3/rds registers we've consumed so far
 730
 731       const uint32_t num_children = return_compiler_type.GetNumFields();
 732
 733       // Since we are in the small struct regime, assume we are not in memory.
 734       is_memory = false;
 735
 736       for (uint32_t idx = 0; idx < num_children; idx++) {
 737         std::string name;
 738         uint64_t field_bit_offset = 0;
 739         bool is_signed;
 740         bool is_complex;
 741         uint32_t count;
 742
 743         CompilerType field_compiler_type = return_compiler_type.GetFieldAtIndex(
 744             idx, name, &field_bit_offset, nullptr, nullptr);
 745         const size_t field_bit_width = field_compiler_type.GetBitSize(&thread);
 746
 747         // If there are any unaligned fields, this is stored in memory.
 748         if (field_bit_offset % field_bit_width != 0) {
 749           is_memory = true;
 750           break;
 751         }
 752
 753         uint32_t field_byte_width = field_bit_width / 8;
 754         uint32_t field_byte_offset = field_bit_offset / 8;
 755
 756         DataExtractor *copy_from_extractor = nullptr;
 757         uint32_t copy_from_offset = 0;
 758
 759         if (field_compiler_type.IsIntegerOrEnumerationType(is_signed) ||
 760             field_compiler_type.IsPointerType()) {
 761           if (integer_bytes < 8) {
 762             if (integer_bytes + field_byte_width <= 8) {
 763               // This is in RAX, copy from register to our result structure:
 764               copy_from_extractor = &r3_data;
 765               copy_from_offset = integer_bytes;
 766               integer_bytes += field_byte_width;
 767             } else {
 768               // The next field wouldn't fit in the remaining space, so we
 769               // pushed it to rdx.
 770               copy_from_extractor = &rdx_data;
 771               copy_from_offset = 0;
 772               integer_bytes = 8 + field_byte_width;
 773             }
 774           } else if (integer_bytes + field_byte_width <= 16) {
 775             copy_from_extractor = &rdx_data;
 776             copy_from_offset = integer_bytes - 8;
 777             integer_bytes += field_byte_width;
 778           } else {
 779             // The last field didn't fit.  I can't see how that would happen w/o
 780             // the overall size being
 781             // greater than 16 bytes.  For now, return a nullptr return value
 782             // object.
 783             return return_valobj_sp;
 784           }
 785         } else if (field_compiler_type.IsFloatingPointType(count, is_complex)) {
 786           // Structs with long doubles are always passed in memory.
 787           if (field_bit_width == 128) {
 788             is_memory = true;
 789             break;
 790           } else if (field_bit_width == 64) {
 791             copy_from_offset = 0;
 792             fp_bytes += field_byte_width;
 793           } else if (field_bit_width == 32) {
 794             // This one is kind of complicated.  If we are in an "eightbyte"
 795             // with another float, we'll
 796             // be stuffed into an xmm register with it.  If we are in an
 797             // "eightbyte" with one or more ints,
 798             // then we will be stuffed into the appropriate GPR with them.
 799             bool in_gpr;
 800             if (field_byte_offset % 8 == 0) {
 801               // We are at the beginning of one of the eightbytes, so check the
 802               // next element (if any)
 803               if (idx == num_children - 1)
 804                 in_gpr = false;
 805               else {
 806                 uint64_t next_field_bit_offset = 0;
 807                 CompilerType next_field_compiler_type =
 808                     return_compiler_type.GetFieldAtIndex(idx + 1, name,
 809                                                          &next_field_bit_offset,
 810                                                          nullptr, nullptr);
 811                 if (next_field_compiler_type.IsIntegerOrEnumerationType(
 812                         is_signed))
 813                   in_gpr = true;
 814                 else {
 815                   copy_from_offset = 0;
 816                   in_gpr = false;
 817                 }
 818               }
 819             } else if (field_byte_offset % 4 == 0) {
 820               // We are inside of an eightbyte, so see if the field before us is
 821               // floating point:
 822               // This could happen if somebody put padding in the structure.
 823               if (idx == 0)
 824                 in_gpr = false;
 825               else {
 826                 uint64_t prev_field_bit_offset = 0;
 827                 CompilerType prev_field_compiler_type =
 828                     return_compiler_type.GetFieldAtIndex(idx - 1, name,
 829                                                          &prev_field_bit_offset,
 830                                                          nullptr, nullptr);
 831                 if (prev_field_compiler_type.IsIntegerOrEnumerationType(
 832                         is_signed))
 833                   in_gpr = true;
 834                 else {
 835                   copy_from_offset = 4;
 836                   in_gpr = false;
 837                 }
 838               }
 839             } else {
 840               is_memory = true;
 841               continue;
 842             }
 843
 844             // Okay, we've figured out whether we are in GPR or XMM, now figure
 845             // out which one.
 846             if (in_gpr) {
 847               if (integer_bytes < 8) {
 848                 // This is in RAX, copy from register to our result structure:
 849                 copy_from_extractor = &r3_data;
 850                 copy_from_offset = integer_bytes;
 851                 integer_bytes += field_byte_width;
 852               } else {
 853                 copy_from_extractor = &rdx_data;
 854                 copy_from_offset = integer_bytes - 8;
 855                 integer_bytes += field_byte_width;
 856               }
 857             } else {
 858               fp_bytes += field_byte_width;
 859             }
 860           }
 861         }
 862
 863         // These two tests are just sanity checks.  If I somehow get the
 864         // type calculation wrong above it is better to just return nothing
 865         // than to assert or crash.
 866         if (!copy_from_extractor)
 867           return return_valobj_sp;
 868         if (copy_from_offset + field_byte_width >
 869             copy_from_extractor->GetByteSize())
 870           return return_valobj_sp;
 871
 872         copy_from_extractor->CopyByteOrderedData(
 873             copy_from_offset, field_byte_width,
 874             data_sp->GetBytes() + field_byte_offset, field_byte_width,
 875             target_byte_order);
 876       }
 877
 878       if (!is_memory) {
 879         // The result is in our data buffer.  Let's make a variable object out
 880         // of it:
 881         return_valobj_sp = ValueObjectConstResult::Create(
 882             &thread, return_compiler_type, ConstString(""), return_ext);
 883       }
 884     }
 885
 886     // FIXME: This is just taking a guess, r3 may very well no longer hold the
 887     // return storage location.
 888     // If we are going to do this right, when we make a new frame we should
 889     // check to see if it uses a memory
 890     // return, and if we are at the first instruction and if so stash away the
 891     // return location.  Then we would
 892     // only return the memory return value if we know it is valid.
 893
 894     if (is_memory) {
 895       unsigned r3_id =
 896           reg_ctx_sp->GetRegisterInfoByName("r3", 0)->kinds[eRegisterKindLLDB];
 897       lldb::addr_t storage_addr =
 898           (uint64_t)thread.GetRegisterContext()->ReadRegisterAsUnsigned(r3_id,
 899                                                                         0);
 900       return_valobj_sp = ValueObjectMemory::Create(
 901           &thread, "", Address(storage_addr, nullptr), return_compiler_type);
 902     }
 903   }
 904
 905   return return_valobj_sp;
 906 }
 907
 908 bool ABISysV_ppc::CreateFunctionEntryUnwindPlan(UnwindPlan &unwind_plan) {
 909   unwind_plan.Clear();
 910   unwind_plan.SetRegisterKind(eRegisterKindDWARF);
 911
 912   uint32_t lr_reg_num = dwarf_lr;
 913   uint32_t sp_reg_num = dwarf_r1;
 914   uint32_t pc_reg_num = dwarf_pc;
 915
 916   UnwindPlan::RowSP row(new UnwindPlan::Row);
 917
 918   // Our Call Frame Address is the stack pointer value
 919   row->GetCFAValue().SetIsRegisterPlusOffset(sp_reg_num, 0);
 920
 921   // The previous PC is in the LR
 922   row->SetRegisterLocationToRegister(pc_reg_num, lr_reg_num, true);
 923   unwind_plan.AppendRow(row);
 924
 925   // All other registers are the same.
 926
 927   unwind_plan.SetSourceName("ppc at-func-entry default");
 928   unwind_plan.SetSourcedFromCompiler(eLazyBoolNo);
 929
 930   return true;
 931 }
 932
 933 bool ABISysV_ppc::CreateDefaultUnwindPlan(UnwindPlan &unwind_plan) {
 934   unwind_plan.Clear();
 935   unwind_plan.SetRegisterKind(eRegisterKindDWARF);
 936
 937   uint32_t sp_reg_num = dwarf_r1;
 938   uint32_t pc_reg_num = dwarf_lr;
 939
 940   UnwindPlan::RowSP row(new UnwindPlan::Row);
 941
 942   const int32_t ptr_size = 4;
 943   row->GetCFAValue().SetIsRegisterDereferenced(sp_reg_num);
 944
 945   row->SetRegisterLocationToAtCFAPlusOffset(pc_reg_num, ptr_size * 1, true);
 946   row->SetRegisterLocationToIsCFAPlusOffset(sp_reg_num, 0, true);
 947
 948   unwind_plan.AppendRow(row);
 949   unwind_plan.SetSourceName("ppc default unwind plan");
 950   unwind_plan.SetSourcedFromCompiler(eLazyBoolNo);
 951   unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo);
 952   unwind_plan.SetReturnAddressRegister(dwarf_lr);
 953   return true;
 954 }
 955
 956 bool ABISysV_ppc::RegisterIsVolatile(const RegisterInfo *reg_info) {
 957   return !RegisterIsCalleeSaved(reg_info);
 958 }
 959
 960 // See "Register Usage" in the
 961 // "System V Application Binary Interface"
 962 // "64-bit PowerPC ELF Application Binary Interface Supplement"
 963 // current version is 1.9 released 2004 at
 964 // http://refspecs.linuxfoundation.org/ELF/ppc/PPC-elf64abi-1.9.pdf
 965
 966 bool ABISysV_ppc::RegisterIsCalleeSaved(const RegisterInfo *reg_info) {
 967   if (reg_info) {
 968     // Preserved registers are :
 969     //    r1,r2,r13-r31
 970     //    f14-f31 (not yet)
 971     //    v20-v31 (not yet)
 972     //    vrsave (not yet)
 973
 974     const char *name = reg_info->name;
 975     if (name[0] == 'r') {
 976       if ((name[1] == '1' || name[1] == '2') && name[2] == '\0')
 977         return true;
 978       if (name[1] == '1' && name[2] > '2')
 979         return true;
 980       if ((name[1] == '2' || name[1] == '3') && name[2] != '\0')
 981         return true;
 982     }
 983
 984     if (name[0] == 'f' && name[1] >= '0' && name[1] <= '9') {
 985       if (name[3] == '1' && name[4] >= '4')
 986         return true;
 987       if ((name[3] == '2' || name[3] == '3') && name[4] != '\0')
 988         return true;
 989     }
 990
 991     if (name[0] == 's' && name[1] == 'p' && name[2] == '\0') // sp
 992       return true;
 993     if (name[0] == 'f' && name[1] == 'p' && name[2] == '\0') // fp
 994       return true;
 995     if (name[0] == 'p' && name[1] == 'c' && name[2] == '\0') // pc
 996       return true;
 997   }
 998   return false;
 999 }
1000
1001 void ABISysV_ppc::Initialize() {
1002   PluginManager::RegisterPlugin(GetPluginNameStatic(),
1003                                 "System V ABI for ppc targets", CreateInstance);
1004 }
1005
1006 void ABISysV_ppc::Terminate() {
1007   PluginManager::UnregisterPlugin(CreateInstance);
1008 }
1009
1010 lldb_private::ConstString ABISysV_ppc::GetPluginNameStatic() {
1011   static ConstString g_name("sysv-ppc");
1012   return g_name;
1013 }
1014
1015 //------------------------------------------------------------------
1016 // PluginInterface protocol
1017 //------------------------------------------------------------------
1018
1019 lldb_private::ConstString ABISysV_ppc::GetPluginName() {
1020   return GetPluginNameStatic();
1021 }
1022
1023 uint32_t ABISysV_ppc::GetPluginVersion() { return 1; }