//===-- ABISysV_ppc64.cpp --------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "ABISysV_ppc64.h"

#include "lldb/Core/ConstString.h"
#include "lldb/Core/DataExtractor.h"
#include "lldb/Core/Error.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Core/RegisterValue.h"
#include "lldb/Core/Value.h"
#include "lldb/Core/ValueObjectConstResult.h"
#include "lldb/Core/ValueObjectRegister.h"
#include "lldb/Core/ValueObjectMemory.h"
#include "lldb/Symbol/ClangASTContext.h"
#include "lldb/Symbol/UnwindPlan.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/StackFrame.h"
#include "lldb/Target/Thread.h"

#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/Triple.h"

using namespace lldb;
using namespace lldb_private;

enum gcc_dwarf_regnums
{
    gcc_dwarf_r0 = 0,
    gcc_dwarf_r1,
    gcc_dwarf_r2,
    gcc_dwarf_r3,
    gcc_dwarf_r4,
    gcc_dwarf_r5,
    gcc_dwarf_r6,
    gcc_dwarf_r7,
    gcc_dwarf_r8,
    gcc_dwarf_r9,
    gcc_dwarf_r10,
    gcc_dwarf_r11,
    gcc_dwarf_r12,
    gcc_dwarf_r13,
    gcc_dwarf_r14,
    gcc_dwarf_r15,
    gcc_dwarf_r16,
    gcc_dwarf_r17,
    gcc_dwarf_r18,
    gcc_dwarf_r19,
    gcc_dwarf_r20,
    gcc_dwarf_r21,
    gcc_dwarf_r22,
    gcc_dwarf_r23,
    gcc_dwarf_r24,
    gcc_dwarf_r25,
    gcc_dwarf_r26,
    gcc_dwarf_r27,
    gcc_dwarf_r28,
    gcc_dwarf_r29,
    gcc_dwarf_r30,
    gcc_dwarf_r31,
    gcc_dwarf_f0,
    gcc_dwarf_f1,
    gcc_dwarf_f2,
    gcc_dwarf_f3,
    gcc_dwarf_f4,
    gcc_dwarf_f5,
    gcc_dwarf_f6,
    gcc_dwarf_f7,
    gcc_dwarf_f8,
    gcc_dwarf_f9,
    gcc_dwarf_f10,
    gcc_dwarf_f11,
    gcc_dwarf_f12,
    gcc_dwarf_f13,
    gcc_dwarf_f14,
    gcc_dwarf_f15,
    gcc_dwarf_f16,
    gcc_dwarf_f17,
    gcc_dwarf_f18,
    gcc_dwarf_f19,
    gcc_dwarf_f20,
    gcc_dwarf_f21,
    gcc_dwarf_f22,
    gcc_dwarf_f23,
    gcc_dwarf_f24,
    gcc_dwarf_f25,
    gcc_dwarf_f26,
    gcc_dwarf_f27,
    gcc_dwarf_f28,
    gcc_dwarf_f29,
    gcc_dwarf_f30,
    gcc_dwarf_f31,
    gcc_dwarf_cr,
    gcc_dwarf_fpscr,
    gcc_dwarf_xer = 101,
    gcc_dwarf_lr = 108,
    gcc_dwarf_ctr,
    gcc_dwarf_pc,
    gcc_dwarf_cfa,
};

enum gdb_regnums
{
    gdb_r0 = 0,
    gdb_r1,
    gdb_r2,
    gdb_r3,
    gdb_r4,
    gdb_r5,
    gdb_r6,
    gdb_r7,
    gdb_r8,
    gdb_r9,
    gdb_r10,
    gdb_r11,
    gdb_r12,
    gdb_r13,
    gdb_r14,
    gdb_r15,
    gdb_r16,
    gdb_r17,
    gdb_r18,
    gdb_r19,
    gdb_r20,
    gdb_r21,
    gdb_r22,
    gdb_r23,
    gdb_r24,
    gdb_r25,
    gdb_r26,
    gdb_r27,
    gdb_r28,
    gdb_r29,
    gdb_r30,
    gdb_r31,
    gdb_lr,
    gdb_cr,
    gdb_xer,
    gdb_ctr,
    gdb_pc,
};


// Note that the size and offset will be updated by platform-specific classes.
#define DEFINE_GPR(reg, alt, kind1, kind2, kind3, kind4)           \
    { #reg, alt, 8, 0, eEncodingUint, \
      eFormatHex, { kind1, kind2, kind3, kind4}, NULL, NULL }
static const RegisterInfo
g_register_infos[] =
{
    // General purpose registers.                 GCC,                  DWARF,              Generic,                GDB
    DEFINE_GPR(r0,       NULL,  gcc_dwarf_r0,    gcc_dwarf_r0,    LLDB_INVALID_REGNUM,    gdb_r0),
    DEFINE_GPR(r1,       "sp",  gcc_dwarf_r1,    gcc_dwarf_r1,    LLDB_REGNUM_GENERIC_SP, gdb_r1),
    DEFINE_GPR(r2,       NULL,  gcc_dwarf_r2,    gcc_dwarf_r2,    LLDB_INVALID_REGNUM,    gdb_r2),
    DEFINE_GPR(r3,       "arg1",gcc_dwarf_r3,    gcc_dwarf_r3,    LLDB_REGNUM_GENERIC_ARG1, gdb_r3),
    DEFINE_GPR(r4,       "arg2",gcc_dwarf_r4,    gcc_dwarf_r4,    LLDB_REGNUM_GENERIC_ARG2 ,gdb_r4),
    DEFINE_GPR(r5,       "arg3",gcc_dwarf_r5,    gcc_dwarf_r5,    LLDB_REGNUM_GENERIC_ARG3, gdb_r5),
    DEFINE_GPR(r6,       "arg4",gcc_dwarf_r6,    gcc_dwarf_r6,    LLDB_REGNUM_GENERIC_ARG4, gdb_r6),
    DEFINE_GPR(r7,       "arg5",gcc_dwarf_r7,    gcc_dwarf_r7,    LLDB_REGNUM_GENERIC_ARG5, gdb_r7),
    DEFINE_GPR(r8,       "arg6",gcc_dwarf_r8,    gcc_dwarf_r8,    LLDB_REGNUM_GENERIC_ARG6, gdb_r8),
    DEFINE_GPR(r9,       "arg7",gcc_dwarf_r9,    gcc_dwarf_r9,    LLDB_REGNUM_GENERIC_ARG7, gdb_r9),
    DEFINE_GPR(r10,      "arg8",gcc_dwarf_r10,   gcc_dwarf_r10,   LLDB_REGNUM_GENERIC_ARG8, gdb_r10),
    DEFINE_GPR(r11,      NULL,  gcc_dwarf_r11,   gcc_dwarf_r11,   LLDB_INVALID_REGNUM,    gdb_r11),
    DEFINE_GPR(r12,      NULL,  gcc_dwarf_r12,   gcc_dwarf_r12,   LLDB_INVALID_REGNUM,    gdb_r12),
    DEFINE_GPR(r13,      NULL,  gcc_dwarf_r13,   gcc_dwarf_r13,   LLDB_INVALID_REGNUM,    gdb_r13),
    DEFINE_GPR(r14,      NULL,  gcc_dwarf_r14,   gcc_dwarf_r14,   LLDB_INVALID_REGNUM,    gdb_r14),
    DEFINE_GPR(r15,      NULL,  gcc_dwarf_r15,   gcc_dwarf_r15,   LLDB_INVALID_REGNUM,    gdb_r15),
    DEFINE_GPR(r16,      NULL,  gcc_dwarf_r16,   gcc_dwarf_r16,   LLDB_INVALID_REGNUM,    gdb_r16),
    DEFINE_GPR(r17,      NULL,  gcc_dwarf_r17,   gcc_dwarf_r17,   LLDB_INVALID_REGNUM,    gdb_r17),
    DEFINE_GPR(r18,      NULL,  gcc_dwarf_r18,   gcc_dwarf_r18,   LLDB_INVALID_REGNUM,    gdb_r18),
    DEFINE_GPR(r19,      NULL,  gcc_dwarf_r19,   gcc_dwarf_r19,   LLDB_INVALID_REGNUM,    gdb_r19),
    DEFINE_GPR(r20,      NULL,  gcc_dwarf_r20,   gcc_dwarf_r20,   LLDB_INVALID_REGNUM,    gdb_r20),
    DEFINE_GPR(r21,      NULL,  gcc_dwarf_r21,   gcc_dwarf_r21,   LLDB_INVALID_REGNUM,    gdb_r21),
    DEFINE_GPR(r22,      NULL,  gcc_dwarf_r22,   gcc_dwarf_r22,   LLDB_INVALID_REGNUM,    gdb_r22),
    DEFINE_GPR(r23,      NULL,  gcc_dwarf_r23,   gcc_dwarf_r23,   LLDB_INVALID_REGNUM,    gdb_r23),
    DEFINE_GPR(r24,      NULL,  gcc_dwarf_r24,   gcc_dwarf_r24,   LLDB_INVALID_REGNUM,    gdb_r24),
    DEFINE_GPR(r25,      NULL,  gcc_dwarf_r25,   gcc_dwarf_r25,   LLDB_INVALID_REGNUM,    gdb_r25),
    DEFINE_GPR(r26,      NULL,  gcc_dwarf_r26,   gcc_dwarf_r26,   LLDB_INVALID_REGNUM,    gdb_r26),
    DEFINE_GPR(r27,      NULL,  gcc_dwarf_r27,   gcc_dwarf_r27,   LLDB_INVALID_REGNUM,    gdb_r27),
    DEFINE_GPR(r28,      NULL,  gcc_dwarf_r28,   gcc_dwarf_r28,   LLDB_INVALID_REGNUM,    gdb_r28),
    DEFINE_GPR(r29,      NULL,  gcc_dwarf_r29,   gcc_dwarf_r29,   LLDB_INVALID_REGNUM,    gdb_r29),
    DEFINE_GPR(r30,      NULL,  gcc_dwarf_r30,   gcc_dwarf_r30,   LLDB_INVALID_REGNUM,    gdb_r30),
    DEFINE_GPR(r31,      NULL,  gcc_dwarf_r31,   gcc_dwarf_r31,   LLDB_INVALID_REGNUM,    gdb_r31),
    DEFINE_GPR(lr,       "lr",  gcc_dwarf_lr,    gcc_dwarf_lr,    LLDB_REGNUM_GENERIC_RA, gdb_lr),
    DEFINE_GPR(cr,       "cr",  gcc_dwarf_cr,    gcc_dwarf_cr,    LLDB_REGNUM_GENERIC_FLAGS, LLDB_INVALID_REGNUM),
    DEFINE_GPR(xer,      "xer", gcc_dwarf_xer,   gcc_dwarf_xer,   LLDB_INVALID_REGNUM,    LLDB_INVALID_REGNUM),
    DEFINE_GPR(ctr,      "ctr", gcc_dwarf_ctr,   gcc_dwarf_ctr,   LLDB_INVALID_REGNUM,    LLDB_INVALID_REGNUM),
    DEFINE_GPR(pc,       "pc",  gcc_dwarf_pc,    gcc_dwarf_pc,    LLDB_REGNUM_GENERIC_PC, LLDB_INVALID_REGNUM),
    { NULL, NULL, 8, 0, eEncodingUint, eFormatHex, { gcc_dwarf_cfa, gcc_dwarf_cfa, LLDB_INVALID_REGNUM, LLDB_INVALID_REGNUM}, NULL, NULL},
};

static const uint32_t k_num_register_infos = llvm::array_lengthof(g_register_infos);

const lldb_private::RegisterInfo *
ABISysV_ppc64::GetRegisterInfoArray (uint32_t &count)
{
    count = k_num_register_infos;
    return g_register_infos;
}


size_t
ABISysV_ppc64::GetRedZoneSize () const
{
    return 224;
}

//------------------------------------------------------------------
// Static Functions
//------------------------------------------------------------------
ABISP
ABISysV_ppc64::CreateInstance (const ArchSpec &arch)
{
    static ABISP g_abi_sp;
    if (arch.GetTriple().getArch() == llvm::Triple::ppc64)
    {
        if (!g_abi_sp)
            g_abi_sp.reset (new ABISysV_ppc64);
        return g_abi_sp;
    }
    return ABISP();
}

bool
ABISysV_ppc64::PrepareTrivialCall (Thread &thread,
                                    addr_t sp,
                                    addr_t func_addr,
                                    addr_t return_addr,
                                    llvm::ArrayRef<addr_t> args) const
{
    Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));

    if (log)
    {
        StreamString s;
        s.Printf("ABISysV_ppc64::PrepareTrivialCall (tid = 0x%" PRIx64 ", sp = 0x%" PRIx64 ", func_addr = 0x%" PRIx64 ", return_addr = 0x%" PRIx64,
                    thread.GetID(),
                    (uint64_t)sp,
                    (uint64_t)func_addr,
                    (uint64_t)return_addr);

        for (size_t i = 0; i < args.size(); ++i)
            s.Printf (", arg%" PRIu64 " = 0x%" PRIx64, static_cast<uint64_t>(i + 1), args[i]);
        s.PutCString (")");
        log->PutCString(s.GetString().c_str());
    }

    RegisterContext *reg_ctx = thread.GetRegisterContext().get();
    if (!reg_ctx)
        return false;

    const RegisterInfo *reg_info = NULL;

    if (args.size() > 8) // TODO handle more than 8 arguments
        return false;

    for (size_t i = 0; i < args.size(); ++i)
    {
        reg_info = reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1 + i);
        if (log)
            log->Printf("About to write arg%" PRIu64 " (0x%" PRIx64 ") into %s", static_cast<uint64_t>(i + 1), args[i], reg_info->name);
        if (!reg_ctx->WriteRegisterFromUnsigned(reg_info, args[i]))
            return false;
    }

    // First, align the SP

    if (log)
        log->Printf("16-byte aligning SP: 0x%" PRIx64 " to 0x%" PRIx64, (uint64_t)sp, (uint64_t)(sp & ~0xfull));

    sp &= ~(0xfull); // 16-byte alignment

    sp -= 8;

    Error error;
    const RegisterInfo *pc_reg_info = reg_ctx->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);
    const RegisterInfo *sp_reg_info = reg_ctx->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_SP);
    ProcessSP process_sp (thread.GetProcess());

    RegisterValue reg_value;

#if 0
    // This code adds an extra frame so that we don't lose the function that we came from
    // by pushing the PC and the FP and then writing the current FP to point to the FP value
    // we just pushed. It is disabled for now until the stack backtracing code can be debugged.

    // Save current PC
    const RegisterInfo *fp_reg_info = reg_ctx->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_FP);
    if (reg_ctx->ReadRegister(pc_reg_info, reg_value))
    {
        if (log)
            log->Printf("Pushing the current PC onto the stack: 0x%" PRIx64 ": 0x%" PRIx64, (uint64_t)sp, reg_value.GetAsUInt64());

        if (!process_sp->WritePointerToMemory(sp, reg_value.GetAsUInt64(), error))
            return false;

        sp -= 8;

        // Save current FP
        if (reg_ctx->ReadRegister(fp_reg_info, reg_value))
        {
            if (log)
                log->Printf("Pushing the current FP onto the stack: 0x%" PRIx64 ": 0x%" PRIx64, (uint64_t)sp, reg_value.GetAsUInt64());

            if (!process_sp->WritePointerToMemory(sp, reg_value.GetAsUInt64(), error))
                return false;
        }
        // Setup FP backchain
        reg_value.SetUInt64 (sp);

        if (log)
            log->Printf("Writing FP:  0x%" PRIx64 " (for FP backchain)", reg_value.GetAsUInt64());

        if (!reg_ctx->WriteRegister(fp_reg_info, reg_value))
        {
            return false;
        }

        sp -= 8;
    }
#endif

    if (log)
        log->Printf("Pushing the return address onto the stack: 0x%" PRIx64 ": 0x%" PRIx64, (uint64_t)sp, (uint64_t)return_addr);

    // Save return address onto the stack
    if (!process_sp->WritePointerToMemory(sp, return_addr, error))
        return false;

    // %r1 is set to the actual stack value.

    if (log)
        log->Printf("Writing SP: 0x%" PRIx64, (uint64_t)sp);

    if (!reg_ctx->WriteRegisterFromUnsigned (sp_reg_info, sp))
        return false;

    // %pc is set to the address of the called function.

    if (log)
        log->Printf("Writing IP: 0x%" PRIx64, (uint64_t)func_addr);

    if (!reg_ctx->WriteRegisterFromUnsigned (pc_reg_info, func_addr))
        return false;

    return true;
}

static bool ReadIntegerArgument(Scalar           &scalar,
                                unsigned int     bit_width,
                                bool             is_signed,
                                Thread           &thread,
                                uint32_t         *argument_register_ids,
                                unsigned int     &current_argument_register,
                                addr_t           &current_stack_argument)
{
    if (bit_width > 64)
        return false; // Scalar can't hold large integer arguments

    if (current_argument_register < 6)
    {
        scalar = thread.GetRegisterContext()->ReadRegisterAsUnsigned(argument_register_ids[current_argument_register], 0);
        current_argument_register++;
        if (is_signed)
            scalar.SignExtend (bit_width);
    }
    else
    {
        uint32_t byte_size = (bit_width + (8-1))/8;
        Error error;
        if (thread.GetProcess()->ReadScalarIntegerFromMemory(current_stack_argument, byte_size, is_signed, scalar, error))
        {
            current_stack_argument += byte_size;
            return true;
        }
        return false;
    }
    return true;
}

bool
ABISysV_ppc64::GetArgumentValues (Thread &thread,
                                  ValueList &values) const
{
    unsigned int num_values = values.GetSize();
    unsigned int value_index;

    // Extract the register context so we can read arguments from registers

    RegisterContext *reg_ctx = thread.GetRegisterContext().get();

    if (!reg_ctx)
        return false;

    // Get the pointer to the first stack argument so we have a place to start
    // when reading data

    addr_t sp = reg_ctx->GetSP(0);

    if (!sp)
        return false;

    addr_t current_stack_argument = sp + 48; // jump over return address

    uint32_t argument_register_ids[8];

    argument_register_ids[0] = reg_ctx->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG1)->kinds[eRegisterKindLLDB];
    argument_register_ids[1] = reg_ctx->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG2)->kinds[eRegisterKindLLDB];
    argument_register_ids[2] = reg_ctx->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG3)->kinds[eRegisterKindLLDB];
    argument_register_ids[3] = reg_ctx->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG4)->kinds[eRegisterKindLLDB];
    argument_register_ids[4] = reg_ctx->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG5)->kinds[eRegisterKindLLDB];
    argument_register_ids[5] = reg_ctx->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG6)->kinds[eRegisterKindLLDB];
    argument_register_ids[6] = reg_ctx->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG7)->kinds[eRegisterKindLLDB];
    argument_register_ids[7] = reg_ctx->GetRegisterInfo (eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG8)->kinds[eRegisterKindLLDB];

    unsigned int current_argument_register = 0;

    for (value_index = 0;
         value_index < num_values;
         ++value_index)
    {
        Value *value = values.GetValueAtIndex(value_index);

        if (!value)
            return false;

        // We currently only support extracting values with Clang QualTypes.
        // Do we care about others?
        ClangASTType clang_type = value->GetClangType();
        if (!clang_type)
            return false;
        bool is_signed;

        if (clang_type.IsIntegerType (is_signed))
        {
            ReadIntegerArgument(value->GetScalar(),
                                clang_type.GetBitSize(&thread),
                                is_signed,
                                thread,
                                argument_register_ids,
                                current_argument_register,
                                current_stack_argument);
        }
        else if (clang_type.IsPointerType ())
        {
            ReadIntegerArgument(value->GetScalar(),
                                clang_type.GetBitSize(&thread),
                                false,
                                thread,
                                argument_register_ids,
                                current_argument_register,
                                current_stack_argument);
        }
    }

    return true;
}

Error
ABISysV_ppc64::SetReturnValueObject(lldb::StackFrameSP &frame_sp, lldb::ValueObjectSP &new_value_sp)
{
    Error error;
    if (!new_value_sp)
    {
        error.SetErrorString("Empty value object for return value.");
        return error;
    }

    ClangASTType clang_type = new_value_sp->GetClangType();
    if (!clang_type)
    {
        error.SetErrorString ("Null clang type for return value.");
        return error;
    }

    Thread *thread = frame_sp->GetThread().get();

    bool is_signed;
    uint32_t count;
    bool is_complex;

    RegisterContext *reg_ctx = thread->GetRegisterContext().get();

    bool set_it_simple = false;
    if (clang_type.IsIntegerType (is_signed) || clang_type.IsPointerType())
    {
        const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoByName("r3", 0);

        DataExtractor data;
        Error data_error;
        size_t num_bytes = new_value_sp->GetData(data, data_error);
        if (data_error.Fail())
        {
            error.SetErrorStringWithFormat("Couldn't convert return value to raw data: %s", data_error.AsCString());
            return error;
        }
        lldb::offset_t offset = 0;
        if (num_bytes <= 8)
        {
            uint64_t raw_value = data.GetMaxU64(&offset, num_bytes);

            if (reg_ctx->WriteRegisterFromUnsigned (reg_info, raw_value))
                set_it_simple = true;
        }
        else
        {
            error.SetErrorString("We don't support returning longer than 64 bit integer values at present.");
        }

    }
    else if (clang_type.IsFloatingPointType (count, is_complex))
    {
        if (is_complex)
            error.SetErrorString ("We don't support returning complex values at present");
        else
        {
            size_t bit_width = clang_type.GetBitSize(frame_sp.get());
            if (bit_width <= 64)
            {
                DataExtractor data;
                Error data_error;
                size_t num_bytes = new_value_sp->GetData(data, data_error);
                if (data_error.Fail())
                {
                    error.SetErrorStringWithFormat("Couldn't convert return value to raw data: %s", data_error.AsCString());
                    return error;
                }

                unsigned char buffer[16];
                ByteOrder byte_order = data.GetByteOrder();

                data.CopyByteOrderedData (0, num_bytes, buffer, 16, byte_order);
                set_it_simple = true;
            }
            else
            {
                // FIXME - don't know how to do 80 bit long doubles yet.
                error.SetErrorString ("We don't support returning float values > 64 bits at present");
            }
        }
    }

    if (!set_it_simple)
    {
        // Okay we've got a structure or something that doesn't fit in a simple register.
        // We should figure out where it really goes, but we don't support this yet.
        error.SetErrorString ("We only support setting simple integer and float return types at present.");
    }

    return error;
}


ValueObjectSP
ABISysV_ppc64::GetReturnValueObjectSimple (Thread &thread,
                                            ClangASTType &return_clang_type) const
{
    ValueObjectSP return_valobj_sp;
    Value value;

    if (!return_clang_type)
        return return_valobj_sp;

    //value.SetContext (Value::eContextTypeClangType, return_value_type);
    value.SetClangType (return_clang_type);

    RegisterContext *reg_ctx = thread.GetRegisterContext().get();
    if (!reg_ctx)
        return return_valobj_sp;

    const uint32_t type_flags = return_clang_type.GetTypeInfo ();
    if (type_flags & eTypeIsScalar)
    {
        value.SetValueType(Value::eValueTypeScalar);

        bool success = false;
        if (type_flags & eTypeIsInteger)
        {
            // Extract the register context so we can read arguments from registers

            const size_t byte_size = return_clang_type.GetByteSize(nullptr);
            uint64_t raw_value = thread.GetRegisterContext()->ReadRegisterAsUnsigned(reg_ctx->GetRegisterInfoByName("r3", 0), 0);
            const bool is_signed = (type_flags & eTypeIsSigned) != 0;
            switch (byte_size)
            {
            default:
                break;

            case sizeof(uint64_t):
                if (is_signed)
                    value.GetScalar() = (int64_t)(raw_value);
                else
                    value.GetScalar() = (uint64_t)(raw_value);
                success = true;
                break;

            case sizeof(uint32_t):
                if (is_signed)
                    value.GetScalar() = (int32_t)(raw_value & UINT32_MAX);
                else
                    value.GetScalar() = (uint32_t)(raw_value & UINT32_MAX);
                success = true;
                break;

            case sizeof(uint16_t):
                if (is_signed)
                    value.GetScalar() = (int16_t)(raw_value & UINT16_MAX);
                else
                    value.GetScalar() = (uint16_t)(raw_value & UINT16_MAX);
                success = true;
                break;

            case sizeof(uint8_t):
                if (is_signed)
                    value.GetScalar() = (int8_t)(raw_value & UINT8_MAX);
                else
                    value.GetScalar() = (uint8_t)(raw_value & UINT8_MAX);
                success = true;
                break;
            }
        }
        else if (type_flags & eTypeIsFloat)
        {
            if (type_flags & eTypeIsComplex)
            {
                // Don't handle complex yet.
            }
            else
            {
                const size_t byte_size = return_clang_type.GetByteSize(nullptr);
                if (byte_size <= sizeof(long double))
                {
                    const RegisterInfo *f1_info = reg_ctx->GetRegisterInfoByName("f1", 0);
                    RegisterValue f1_value;
                    if (reg_ctx->ReadRegister (f1_info, f1_value))
                    {
                        DataExtractor data;
                        if (f1_value.GetData(data))
                        {
                            lldb::offset_t offset = 0;
                            if (byte_size == sizeof(float))
                            {
                                value.GetScalar() = (float) data.GetFloat(&offset);
                                success = true;
                            }
                            else if (byte_size == sizeof(double))
                            {
                                value.GetScalar() = (double) data.GetDouble(&offset);
                                success = true;
                            }
                        }
                    }
                }
            }
        }

        if (success)
            return_valobj_sp = ValueObjectConstResult::Create (thread.GetStackFrameAtIndex(0).get(),
                                                               value,
                                                               ConstString(""));

    }
    else if (type_flags & eTypeIsPointer)
    {
        unsigned r3_id = reg_ctx->GetRegisterInfoByName("r3", 0)->kinds[eRegisterKindLLDB];
        value.GetScalar() = (uint64_t)thread.GetRegisterContext()->ReadRegisterAsUnsigned(r3_id, 0);
        value.SetValueType(Value::eValueTypeScalar);
        return_valobj_sp = ValueObjectConstResult::Create (thread.GetStackFrameAtIndex(0).get(),
                                                           value,
                                                           ConstString(""));
    }
    else if (type_flags & eTypeIsVector)
    {
        const size_t byte_size = return_clang_type.GetByteSize(nullptr);
        if (byte_size > 0)
        {

            const RegisterInfo *altivec_reg = reg_ctx->GetRegisterInfoByName("v2", 0);
            if (altivec_reg)
            {
                if (byte_size <= altivec_reg->byte_size)
                {
                    ProcessSP process_sp (thread.GetProcess());
                    if (process_sp)
                    {
                        std::unique_ptr<DataBufferHeap> heap_data_ap (new DataBufferHeap(byte_size, 0));
                        const ByteOrder byte_order = process_sp->GetByteOrder();
                        RegisterValue reg_value;
                        if (reg_ctx->ReadRegister(altivec_reg, reg_value))
                        {
                            Error error;
                            if (reg_value.GetAsMemoryData (altivec_reg,
                                                           heap_data_ap->GetBytes(),
                                                           heap_data_ap->GetByteSize(),
                                                           byte_order,
                                                           error))
                            {
                                DataExtractor data (DataBufferSP (heap_data_ap.release()),
                                                    byte_order,
                                                    process_sp->GetTarget().GetArchitecture().GetAddressByteSize());
                                return_valobj_sp = ValueObjectConstResult::Create (&thread,
                                                                                   return_clang_type,
                                                                                   ConstString(""),
                                                                                   data);
                            }
                        }
                    }
                }
            }
        }
    }

    return return_valobj_sp;
}

ValueObjectSP
ABISysV_ppc64::GetReturnValueObjectImpl (Thread &thread, ClangASTType &return_clang_type) const
{
    ValueObjectSP return_valobj_sp;

    if (!return_clang_type)
        return return_valobj_sp;

    ExecutionContext exe_ctx (thread.shared_from_this());
    return_valobj_sp = GetReturnValueObjectSimple(thread, return_clang_type);
    if (return_valobj_sp)
        return return_valobj_sp;

    RegisterContextSP reg_ctx_sp = thread.GetRegisterContext();
    if (!reg_ctx_sp)
        return return_valobj_sp;

    const size_t bit_width = return_clang_type.GetBitSize(&thread);
    if (return_clang_type.IsAggregateType())
    {
        Target *target = exe_ctx.GetTargetPtr();
        bool is_memory = true;
        if (bit_width <= 128)
        {
            ByteOrder target_byte_order = target->GetArchitecture().GetByteOrder();
            DataBufferSP data_sp (new DataBufferHeap(16, 0));
            DataExtractor return_ext (data_sp,
                                      target_byte_order,
                                      target->GetArchitecture().GetAddressByteSize());

            const RegisterInfo *r3_info = reg_ctx_sp->GetRegisterInfoByName("r3", 0);
            const RegisterInfo *rdx_info = reg_ctx_sp->GetRegisterInfoByName("rdx", 0);

            RegisterValue r3_value, rdx_value;
            reg_ctx_sp->ReadRegister (r3_info, r3_value);
            reg_ctx_sp->ReadRegister (rdx_info, rdx_value);

            DataExtractor r3_data, rdx_data;

            r3_value.GetData(r3_data);
            rdx_value.GetData(rdx_data);

            uint32_t fp_bytes = 0;       // Tracks how much of the xmm registers we've consumed so far
            uint32_t integer_bytes = 0;  // Tracks how much of the r3/rds registers we've consumed so far

            const uint32_t num_children = return_clang_type.GetNumFields ();

            // Since we are in the small struct regime, assume we are not in memory.
            is_memory = false;

            for (uint32_t idx = 0; idx < num_children; idx++)
            {
                std::string name;
                uint64_t field_bit_offset = 0;
                bool is_signed;
                bool is_complex;
                uint32_t count;

                ClangASTType field_clang_type = return_clang_type.GetFieldAtIndex (idx, name, &field_bit_offset, NULL, NULL);
                const size_t field_bit_width = field_clang_type.GetBitSize(&thread);

                // If there are any unaligned fields, this is stored in memory.
                if (field_bit_offset % field_bit_width != 0)
                {
                    is_memory = true;
                    break;
                }

                uint32_t field_byte_width = field_bit_width/8;
                uint32_t field_byte_offset = field_bit_offset/8;


                DataExtractor *copy_from_extractor = NULL;
                uint32_t       copy_from_offset    = 0;

                if (field_clang_type.IsIntegerType (is_signed) || field_clang_type.IsPointerType ())
                {
                    if (integer_bytes < 8)
                    {
                        if (integer_bytes + field_byte_width <= 8)
                        {
                            // This is in RAX, copy from register to our result structure:
                            copy_from_extractor = &r3_data;
                            copy_from_offset = integer_bytes;
                            integer_bytes += field_byte_width;
                        }
                        else
                        {
                            // The next field wouldn't fit in the remaining space, so we pushed it to rdx.
                            copy_from_extractor = &rdx_data;
                            copy_from_offset = 0;
                            integer_bytes = 8 + field_byte_width;

                        }
                    }
                    else if (integer_bytes + field_byte_width <= 16)
                    {
                        copy_from_extractor = &rdx_data;
                        copy_from_offset = integer_bytes - 8;
                        integer_bytes += field_byte_width;
                    }
                    else
                    {
                        // The last field didn't fit.  I can't see how that would happen w/o the overall size being
                        // greater than 16 bytes.  For now, return a NULL return value object.
                        return return_valobj_sp;
                    }
                }
                else if (field_clang_type.IsFloatingPointType (count, is_complex))
                {
                    // Structs with long doubles are always passed in memory.
                    if (field_bit_width == 128)
                    {
                        is_memory = true;
                        break;
                    }
                    else if (field_bit_width == 64)
                    {
                        copy_from_offset = 0;
                        fp_bytes += field_byte_width;
                    }
                    else if (field_bit_width == 32)
                    {
                        // This one is kind of complicated.  If we are in an "eightbyte" with another float, we'll
                        // be stuffed into an xmm register with it.  If we are in an "eightbyte" with one or more ints,
                        // then we will be stuffed into the appropriate GPR with them.
                        bool in_gpr;
                        if (field_byte_offset % 8 == 0)
                        {
                            // We are at the beginning of one of the eightbytes, so check the next element (if any)
                            if (idx == num_children - 1)
                                in_gpr = false;
                            else
                            {
                                uint64_t next_field_bit_offset = 0;
                                ClangASTType next_field_clang_type = return_clang_type.GetFieldAtIndex (idx + 1,
                                                                                                        name,
                                                                                                        &next_field_bit_offset,
                                                                                                        NULL,
                                                                                                        NULL);
                                if (next_field_clang_type.IsIntegerType (is_signed))
                                    in_gpr = true;
                                else
                                {
                                    copy_from_offset = 0;
                                    in_gpr = false;
                                }
                            }

                        }
                        else if (field_byte_offset % 4 == 0)
                        {
                            // We are inside of an eightbyte, so see if the field before us is floating point:
                            // This could happen if somebody put padding in the structure.
                            if (idx == 0)
                                in_gpr = false;
                            else
                            {
                                uint64_t prev_field_bit_offset = 0;
                                ClangASTType prev_field_clang_type = return_clang_type.GetFieldAtIndex (idx - 1,
                                                                                                        name,
                                                                                                        &prev_field_bit_offset,
                                                                                                        NULL,
                                                                                                        NULL);
                                if (prev_field_clang_type.IsIntegerType (is_signed))
                                    in_gpr = true;
                                else
                                {
                                    copy_from_offset = 4;
                                    in_gpr = false;
                                }
                            }

                        }
                        else
                        {
                            is_memory = true;
                            continue;
                        }

                        // Okay, we've figured out whether we are in GPR or XMM, now figure out which one.
                        if (in_gpr)
                        {
                            if (integer_bytes < 8)
                            {
                                // This is in RAX, copy from register to our result structure:
                                copy_from_extractor = &r3_data;
                                copy_from_offset = integer_bytes;
                                integer_bytes += field_byte_width;
                            }
                            else
                            {
                                copy_from_extractor = &rdx_data;
                                copy_from_offset = integer_bytes - 8;
                                integer_bytes += field_byte_width;
                            }
                        }
                        else
                        {
                            fp_bytes += field_byte_width;
                        }
                    }
                }

                // These two tests are just sanity checks.  If I somehow get the
                // type calculation wrong above it is better to just return nothing
                // than to assert or crash.
                if (!copy_from_extractor)
                    return return_valobj_sp;
                if (copy_from_offset + field_byte_width > copy_from_extractor->GetByteSize())
                    return return_valobj_sp;

                copy_from_extractor->CopyByteOrderedData (copy_from_offset,
                                                          field_byte_width,
                                                          data_sp->GetBytes() + field_byte_offset,
                                                          field_byte_width,
                                                          target_byte_order);
            }

            if (!is_memory)
            {
                // The result is in our data buffer.  Let's make a variable object out of it:
                return_valobj_sp = ValueObjectConstResult::Create (&thread,
                                                                   return_clang_type,
                                                                   ConstString(""),
                                                                   return_ext);
            }
        }


        // FIXME: This is just taking a guess, r3 may very well no longer hold the return storage location.
        // If we are going to do this right, when we make a new frame we should check to see if it uses a memory
        // return, and if we are at the first instruction and if so stash away the return location.  Then we would
        // only return the memory return value if we know it is valid.

        if (is_memory)
        {
            unsigned r3_id = reg_ctx_sp->GetRegisterInfoByName("r3", 0)->kinds[eRegisterKindLLDB];
            lldb::addr_t storage_addr = (uint64_t)thread.GetRegisterContext()->ReadRegisterAsUnsigned(r3_id, 0);
            return_valobj_sp = ValueObjectMemory::Create (&thread,
                                                          "",
                                                          Address (storage_addr, NULL),
                                                          return_clang_type);
        }
    }

    return return_valobj_sp;
}

bool
ABISysV_ppc64::CreateFunctionEntryUnwindPlan (UnwindPlan &unwind_plan)
{
    unwind_plan.Clear();
    unwind_plan.SetRegisterKind (eRegisterKindDWARF);

    uint32_t lr_reg_num = gcc_dwarf_lr;
    uint32_t sp_reg_num = gcc_dwarf_r1;
    uint32_t pc_reg_num = gcc_dwarf_pc;

    UnwindPlan::RowSP row(new UnwindPlan::Row);

    // Our Call Frame Address is the stack pointer value
    row->GetCFAValue().SetIsRegisterPlusOffset(sp_reg_num, 0);

    // The previous PC is in the LR
    row->SetRegisterLocationToRegister(pc_reg_num, lr_reg_num, true);
    unwind_plan.AppendRow (row);

    // All other registers are the same.

    unwind_plan.SetSourceName ("ppc64 at-func-entry default");
    unwind_plan.SetSourcedFromCompiler (eLazyBoolNo);

    return true;
}

bool
ABISysV_ppc64::CreateDefaultUnwindPlan (UnwindPlan &unwind_plan)
{
    unwind_plan.Clear();
    unwind_plan.SetRegisterKind (eRegisterKindDWARF);

    uint32_t sp_reg_num = gcc_dwarf_r1;
    uint32_t pc_reg_num = gcc_dwarf_lr;

    UnwindPlan::RowSP row(new UnwindPlan::Row);

    const int32_t ptr_size = 8;
    row->GetCFAValue().SetIsRegisterDereferenced(sp_reg_num);

    row->SetRegisterLocationToAtCFAPlusOffset(pc_reg_num, ptr_size * 2, true);
    row->SetRegisterLocationToIsCFAPlusOffset(sp_reg_num, 0, true);
    row->SetRegisterLocationToAtCFAPlusOffset(gcc_dwarf_cr, ptr_size, true);

    unwind_plan.AppendRow (row);
    unwind_plan.SetSourceName ("ppc64 default unwind plan");
    unwind_plan.SetSourcedFromCompiler (eLazyBoolNo);
    unwind_plan.SetUnwindPlanValidAtAllInstructions (eLazyBoolNo);
    unwind_plan.SetReturnAddressRegister(gcc_dwarf_lr);
    return true;
}

bool
ABISysV_ppc64::RegisterIsVolatile (const RegisterInfo *reg_info)
{
    return !RegisterIsCalleeSaved (reg_info);
}



// See "Register Usage" in the
// "System V Application Binary Interface"
// "64-bit PowerPC ELF Application Binary Interface Supplement"
// current version is 1.9 released 2004 at http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.pdf

bool
ABISysV_ppc64::RegisterIsCalleeSaved (const RegisterInfo *reg_info)
{
    if (reg_info)
    {
        // Preserved registers are :
        //    r1,r2,r13-r31
        //    cr2-cr4 (partially preserved)
        //    f14-f31 (not yet)
        //    v20-v31 (not yet)
        //    vrsave (not yet)

        const char *name = reg_info->name;
        if (name[0] == 'r')
        {
            if ((name[1] == '1' || name[1] == '2') && name[2] == '\0')
                return true;
            if (name[1] == '1' && name[2] > '2')
                return true;
            if ((name[1] == '2' || name[1] == '3') && name[2] != '\0')
                return true;
        }

        if (name[0] == 'f' && name[1] >= '0' && name[2] <= '9')
        {
            if (name[2] == '\0')
                return false;
            if (name[1] == '1' && name[2] >= '4')
                return true;
            if ((name[1] == '2' || name[1] == '3') && name[2] != '\0')
                return true;
        }

        if (name[0] == 's' && name[1] == 'p' && name[2] == '\0')   // sp
            return true;
        if (name[0] == 'f' && name[1] == 'p' && name[2] == '\0')   // fp
            return true;
        if (name[0] == 'p' && name[1] == 'c' && name[2] == '\0')   // pc
            return true;
    }
    return false;
}



void
ABISysV_ppc64::Initialize()
{
    PluginManager::RegisterPlugin (GetPluginNameStatic(),
                                   "System V ABI for ppc64 targets",
                                   CreateInstance);
}

void
ABISysV_ppc64::Terminate()
{
    PluginManager::UnregisterPlugin (CreateInstance);
}

lldb_private::ConstString
ABISysV_ppc64::GetPluginNameStatic()
{
    static ConstString g_name("sysv-ppc64");
    return g_name;
}

//------------------------------------------------------------------
// PluginInterface protocol
//------------------------------------------------------------------
lldb_private::ConstString
ABISysV_ppc64::GetPluginName()
{
    return GetPluginNameStatic();
}

uint32_t
ABISysV_ppc64::GetPluginVersion()
{
    return 1;
}

