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llvm-project/lldb/source/Plugins/ABI/X86/ABISysV_x86_64.cpp
Archibald Elliott 62c7f035b4 [NFC][TargetParser] Remove llvm/ADT/Triple.h 
I also ran `git clang-format` to get the headers in the right order for
the new location, which has changed the order of other headers in two
files.
2023-02-07 12:39:46 +00:00

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//===-- ABISysV_x86_64.cpp ------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "ABISysV_x86_64.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/TargetParser/Triple.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Core/Value.h"
#include "lldb/Core/ValueObjectConstResult.h"
#include "lldb/Core/ValueObjectMemory.h"
#include "lldb/Core/ValueObjectRegister.h"
#include "lldb/Symbol/UnwindPlan.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/StackFrame.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Thread.h"
#include "lldb/Utility/ConstString.h"
#include "lldb/Utility/DataExtractor.h"
#include "lldb/Utility/LLDBLog.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/RegisterValue.h"
#include "lldb/Utility/Status.h"
#include <optional>
#include <vector>
using namespace lldb;
using namespace lldb_private;
LLDB_PLUGIN_DEFINE(ABISysV_x86_64)
enum dwarf_regnums {
dwarf_rax = 0,
dwarf_rdx,
dwarf_rcx,
dwarf_rbx,
dwarf_rsi,
dwarf_rdi,
dwarf_rbp,
dwarf_rsp,
dwarf_r8,
dwarf_r9,
dwarf_r10,
dwarf_r11,
dwarf_r12,
dwarf_r13,
dwarf_r14,
dwarf_r15,
dwarf_rip,
};
bool ABISysV_x86_64::GetPointerReturnRegister(const char *&name) {
name = "rax";
return true;
}
size_t ABISysV_x86_64::GetRedZoneSize() const { return 128; }
// Static Functions
ABISP
ABISysV_x86_64::CreateInstance(lldb::ProcessSP process_sp, const ArchSpec &arch) {
const llvm::Triple::ArchType arch_type = arch.GetTriple().getArch();
const llvm::Triple::OSType os_type = arch.GetTriple().getOS();
const llvm::Triple::EnvironmentType os_env =
arch.GetTriple().getEnvironment();
if (arch_type == llvm::Triple::x86_64) {
switch(os_type) {
case llvm::Triple::OSType::IOS:
case llvm::Triple::OSType::TvOS:
case llvm::Triple::OSType::WatchOS:
switch (os_env) {
case llvm::Triple::EnvironmentType::MacABI:
case llvm::Triple::EnvironmentType::Simulator:
case llvm::Triple::EnvironmentType::UnknownEnvironment:
// UnknownEnvironment is needed for older compilers that don't
// support the simulator environment.
return ABISP(new ABISysV_x86_64(std::move(process_sp),
MakeMCRegisterInfo(arch)));
default:
return ABISP();
}
case llvm::Triple::OSType::Darwin:
case llvm::Triple::OSType::FreeBSD:
case llvm::Triple::OSType::Linux:
case llvm::Triple::OSType::MacOSX:
case llvm::Triple::OSType::NetBSD:
case llvm::Triple::OSType::Solaris:
case llvm::Triple::OSType::UnknownOS:
return ABISP(
new ABISysV_x86_64(std::move(process_sp), MakeMCRegisterInfo(arch)));
default:
return ABISP();
}
}
return ABISP();
}
bool ABISysV_x86_64::PrepareTrivialCall(Thread &thread, addr_t sp,
addr_t func_addr, addr_t return_addr,
llvm::ArrayRef<addr_t> args) const {
Log *log = GetLog(LLDBLog::Expressions);
if (log) {
StreamString s;
s.Printf("ABISysV_x86_64::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->PutString(s.GetString());
}
RegisterContext *reg_ctx = thread.GetRegisterContext().get();
if (!reg_ctx)
return false;
const RegisterInfo *reg_info = nullptr;
if (args.size() > 6) // TODO handle more than 6 arguments
return false;
for (size_t i = 0; i < args.size(); ++i) {
reg_info = reg_ctx->GetRegisterInfo(eRegisterKindGeneric,
LLDB_REGNUM_GENERIC_ARG1 + i);
LLDB_LOGF(log, "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
LLDB_LOGF(log, "16-byte aligning SP: 0x%" PRIx64 " to 0x%" PRIx64,
(uint64_t)sp, (uint64_t)(sp & ~0xfull));
sp &= ~(0xfull); // 16-byte alignment
sp -= 8;
Status 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;
LLDB_LOGF(log,
"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;
// %rsp is set to the actual stack value.
LLDB_LOGF(log, "Writing SP: 0x%" PRIx64, (uint64_t)sp);
if (!reg_ctx->WriteRegisterFromUnsigned(sp_reg_info, sp))
return false;
// %rip is set to the address of the called function.
LLDB_LOGF(log, "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;
Status 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_x86_64::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 + 8; // jump over return address
uint32_t argument_register_ids[6];
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];
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?
CompilerType compiler_type = value->GetCompilerType();
std::optional<uint64_t> bit_size = compiler_type.GetBitSize(&thread);
if (!bit_size)
return false;
bool is_signed;
if (compiler_type.IsIntegerOrEnumerationType(is_signed)) {
ReadIntegerArgument(value->GetScalar(), *bit_size, is_signed, thread,
argument_register_ids, current_argument_register,
current_stack_argument);
} else if (compiler_type.IsPointerType()) {
ReadIntegerArgument(value->GetScalar(), *bit_size, false, thread,
argument_register_ids, current_argument_register,
current_stack_argument);
}
}
return true;
}
Status ABISysV_x86_64::SetReturnValueObject(lldb::StackFrameSP &frame_sp,
lldb::ValueObjectSP &new_value_sp) {
Status error;
if (!new_value_sp) {
error.SetErrorString("Empty value object for return value.");
return error;
}
CompilerType compiler_type = new_value_sp->GetCompilerType();
if (!compiler_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 (compiler_type.IsIntegerOrEnumerationType(is_signed) ||
compiler_type.IsPointerType()) {
const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoByName("rax", 0);
DataExtractor data;
Status 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 (compiler_type.IsFloatingPointType(count, is_complex)) {
if (is_complex)
error.SetErrorString(
"We don't support returning complex values at present");
else {
std::optional<uint64_t> bit_width =
compiler_type.GetBitSize(frame_sp.get());
if (!bit_width) {
error.SetErrorString("can't get type size");
return error;
}
if (*bit_width <= 64) {
const RegisterInfo *xmm0_info =
reg_ctx->GetRegisterInfoByName("xmm0", 0);
RegisterValue xmm0_value;
DataExtractor data;
Status 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);
xmm0_value.SetBytes(buffer, 16, byte_order);
reg_ctx->WriteRegister(xmm0_info, xmm0_value);
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_x86_64::GetReturnValueObjectSimple(
Thread &thread, CompilerType &return_compiler_type) const {
ValueObjectSP return_valobj_sp;
Value value;
if (!return_compiler_type)
return return_valobj_sp;
// value.SetContext (Value::eContextTypeClangType, return_value_type);
value.SetCompilerType(return_compiler_type);
RegisterContext *reg_ctx = thread.GetRegisterContext().get();
if (!reg_ctx)
return return_valobj_sp;
const uint32_t type_flags = return_compiler_type.GetTypeInfo();
if (type_flags & eTypeIsScalar) {
value.SetValueType(Value::ValueType::Scalar);
bool success = false;
if (type_flags & eTypeIsInteger) {
// Extract the register context so we can read arguments from registers
std::optional<uint64_t> byte_size =
return_compiler_type.GetByteSize(&thread);
if (!byte_size)
return return_valobj_sp;
uint64_t raw_value = thread.GetRegisterContext()->ReadRegisterAsUnsigned(
reg_ctx->GetRegisterInfoByName("rax", 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 {
std::optional<uint64_t> byte_size =
return_compiler_type.GetByteSize(&thread);
if (byte_size && *byte_size <= sizeof(long double)) {
const RegisterInfo *xmm0_info =
reg_ctx->GetRegisterInfoByName("xmm0", 0);
RegisterValue xmm0_value;
if (reg_ctx->ReadRegister(xmm0_info, xmm0_value)) {
DataExtractor data;
if (xmm0_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;
} else if (*byte_size == sizeof(long double)) {
// Don't handle long double since that can be encoded as 80 bit
// floats...
}
}
}
}
}
}
if (success)
return_valobj_sp = ValueObjectConstResult::Create(
thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));
} else if (type_flags & eTypeIsPointer) {
unsigned rax_id =
reg_ctx->GetRegisterInfoByName("rax", 0)->kinds[eRegisterKindLLDB];
value.GetScalar() =
(uint64_t)thread.GetRegisterContext()->ReadRegisterAsUnsigned(rax_id,
0);
value.SetValueType(Value::ValueType::Scalar);
return_valobj_sp = ValueObjectConstResult::Create(
thread.GetStackFrameAtIndex(0).get(), value, ConstString(""));
} else if (type_flags & eTypeIsVector) {
std::optional<uint64_t> byte_size =
return_compiler_type.GetByteSize(&thread);
if (byte_size && *byte_size > 0) {
const RegisterInfo *altivec_reg =
reg_ctx->GetRegisterInfoByName("xmm0", 0);
if (altivec_reg == nullptr)
altivec_reg = reg_ctx->GetRegisterInfoByName("mm0", 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_up(
new DataBufferHeap(*byte_size, 0));
const ByteOrder byte_order = process_sp->GetByteOrder();
RegisterValue reg_value;
if (reg_ctx->ReadRegister(altivec_reg, reg_value)) {
Status error;
if (reg_value.GetAsMemoryData(
*altivec_reg, heap_data_up->GetBytes(),
heap_data_up->GetByteSize(), byte_order, error)) {
DataExtractor data(DataBufferSP(heap_data_up.release()),
byte_order,
process_sp->GetTarget()
.GetArchitecture()
.GetAddressByteSize());
return_valobj_sp = ValueObjectConstResult::Create(
&thread, return_compiler_type, ConstString(""), data);
}
}
}
} else if (*byte_size <= altivec_reg->byte_size * 2) {
const RegisterInfo *altivec_reg2 =
reg_ctx->GetRegisterInfoByName("xmm1", 0);
if (altivec_reg2) {
ProcessSP process_sp(thread.GetProcess());
if (process_sp) {
std::unique_ptr<DataBufferHeap> heap_data_up(
new DataBufferHeap(*byte_size, 0));
const ByteOrder byte_order = process_sp->GetByteOrder();
RegisterValue reg_value;
RegisterValue reg_value2;
if (reg_ctx->ReadRegister(altivec_reg, reg_value) &&
reg_ctx->ReadRegister(altivec_reg2, reg_value2)) {
Status error;
if (reg_value.GetAsMemoryData(
*altivec_reg, heap_data_up->GetBytes(),
altivec_reg->byte_size, byte_order, error) &&
reg_value2.GetAsMemoryData(
*altivec_reg2,
heap_data_up->GetBytes() + altivec_reg->byte_size,
heap_data_up->GetByteSize() - altivec_reg->byte_size,
byte_order, error)) {
DataExtractor data(DataBufferSP(heap_data_up.release()),
byte_order,
process_sp->GetTarget()
.GetArchitecture()
.GetAddressByteSize());
return_valobj_sp = ValueObjectConstResult::Create(
&thread, return_compiler_type, ConstString(""), data);
}
}
}
}
}
}
}
}
return return_valobj_sp;
}
// The compiler will flatten the nested aggregate type into single
// layer and push the value to stack
// This helper function will flatten an aggregate type
// and return true if it can be returned in register(s) by value
// return false if the aggregate is in memory
static bool FlattenAggregateType(
Thread &thread, ExecutionContext &exe_ctx,
CompilerType &return_compiler_type,
uint32_t data_byte_offset,
std::vector<uint32_t> &aggregate_field_offsets,
std::vector<CompilerType> &aggregate_compiler_types) {
const uint32_t num_children = return_compiler_type.GetNumFields();
for (uint32_t idx = 0; idx < num_children; ++idx) {
std::string name;
bool is_signed;
uint32_t count;
bool is_complex;
uint64_t field_bit_offset = 0;
CompilerType field_compiler_type = return_compiler_type.GetFieldAtIndex(
idx, name, &field_bit_offset, nullptr, nullptr);
std::optional<uint64_t> field_bit_width =
field_compiler_type.GetBitSize(&thread);
// if we don't know the size of the field (e.g. invalid type), exit
if (!field_bit_width || *field_bit_width == 0) {
return false;
}
uint32_t field_byte_offset = field_bit_offset / 8 + data_byte_offset;
const uint32_t field_type_flags = field_compiler_type.GetTypeInfo();
if (field_compiler_type.IsIntegerOrEnumerationType(is_signed) ||
field_compiler_type.IsPointerType() ||
field_compiler_type.IsFloatingPointType(count, is_complex)) {
aggregate_field_offsets.push_back(field_byte_offset);
aggregate_compiler_types.push_back(field_compiler_type);
} else if (field_type_flags & eTypeHasChildren) {
if (!FlattenAggregateType(thread, exe_ctx, field_compiler_type,
field_byte_offset, aggregate_field_offsets,
aggregate_compiler_types)) {
return false;
}
}
}
return true;
}
ValueObjectSP ABISysV_x86_64::GetReturnValueObjectImpl(
Thread &thread, CompilerType &return_compiler_type) const {
ValueObjectSP return_valobj_sp;
if (!return_compiler_type)
return return_valobj_sp;
ExecutionContext exe_ctx(thread.shared_from_this());
return_valobj_sp = GetReturnValueObjectSimple(thread, return_compiler_type);
if (return_valobj_sp)
return return_valobj_sp;
RegisterContextSP reg_ctx_sp = thread.GetRegisterContext();
if (!reg_ctx_sp)
return return_valobj_sp;
std::optional<uint64_t> bit_width = return_compiler_type.GetBitSize(&thread);
if (!bit_width)
return return_valobj_sp;
if (return_compiler_type.IsAggregateType()) {
Target *target = exe_ctx.GetTargetPtr();
bool is_memory = true;
std::vector<uint32_t> aggregate_field_offsets;
std::vector<CompilerType> aggregate_compiler_types;
auto ts = return_compiler_type.GetTypeSystem();
if (ts && ts->CanPassInRegisters(return_compiler_type) &&
*bit_width <= 128 &&
FlattenAggregateType(thread, exe_ctx, return_compiler_type, 0,
aggregate_field_offsets,
aggregate_compiler_types)) {
ByteOrder byte_order = target->GetArchitecture().GetByteOrder();
WritableDataBufferSP data_sp(new DataBufferHeap(16, 0));
DataExtractor return_ext(data_sp, byte_order,
target->GetArchitecture().GetAddressByteSize());
const RegisterInfo *rax_info =
reg_ctx_sp->GetRegisterInfoByName("rax", 0);
const RegisterInfo *rdx_info =
reg_ctx_sp->GetRegisterInfoByName("rdx", 0);
const RegisterInfo *xmm0_info =
reg_ctx_sp->GetRegisterInfoByName("xmm0", 0);
const RegisterInfo *xmm1_info =
reg_ctx_sp->GetRegisterInfoByName("xmm1", 0);
RegisterValue rax_value, rdx_value, xmm0_value, xmm1_value;
reg_ctx_sp->ReadRegister(rax_info, rax_value);
reg_ctx_sp->ReadRegister(rdx_info, rdx_value);
reg_ctx_sp->ReadRegister(xmm0_info, xmm0_value);
reg_ctx_sp->ReadRegister(xmm1_info, xmm1_value);
DataExtractor rax_data, rdx_data, xmm0_data, xmm1_data;
rax_value.GetData(rax_data);
rdx_value.GetData(rdx_data);
xmm0_value.GetData(xmm0_data);
xmm1_value.GetData(xmm1_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 rax/rds registers we've consumed so far
// in case of the returned type is a subclass of non-abstract-base class
// it will have a padding to skip the base content
if (aggregate_field_offsets.size()) {
fp_bytes = aggregate_field_offsets[0];
integer_bytes = aggregate_field_offsets[0];
}
const uint32_t num_children = aggregate_compiler_types.size();
// 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++) {
bool is_signed;
uint32_t count;
bool is_complex;
CompilerType field_compiler_type = aggregate_compiler_types[idx];
uint32_t field_byte_width = (uint32_t) (*field_compiler_type.GetByteSize(&thread));
uint32_t field_byte_offset = aggregate_field_offsets[idx];
uint32_t field_bit_width = field_byte_width * 8;
DataExtractor *copy_from_extractor = nullptr;
uint32_t copy_from_offset = 0;
if (field_compiler_type.IsIntegerOrEnumerationType(is_signed) ||
field_compiler_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 = &rax_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 nullptr return value object.
return return_valobj_sp;
}
} else if (field_compiler_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) {
// These have to be in a single xmm register.
if (fp_bytes == 0)
copy_from_extractor = &xmm0_data;
else
copy_from_extractor = &xmm1_data;
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 {
CompilerType next_field_compiler_type =
aggregate_compiler_types[idx + 1];
if (next_field_compiler_type.IsIntegerOrEnumerationType(
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 {
CompilerType prev_field_compiler_type =
aggregate_compiler_types[idx - 1];
if (prev_field_compiler_type.IsIntegerOrEnumerationType(
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 = &rax_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 {
if (fp_bytes < 8)
copy_from_extractor = &xmm0_data;
else
copy_from_extractor = &xmm1_data;
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,
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_compiler_type, ConstString(""), return_ext);
}
}
// FIXME: This is just taking a guess, rax 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 rax_id =
reg_ctx_sp->GetRegisterInfoByName("rax", 0)->kinds[eRegisterKindLLDB];
lldb::addr_t storage_addr =
(uint64_t)thread.GetRegisterContext()->ReadRegisterAsUnsigned(rax_id,
0);
return_valobj_sp = ValueObjectMemory::Create(
&thread, "", Address(storage_addr, nullptr), return_compiler_type);
}
}
return return_valobj_sp;
}
// This defines the CFA as rsp+8
// the saved pc is at CFA-8 (i.e. rsp+0)
// The saved rsp is CFA+0
bool ABISysV_x86_64::CreateFunctionEntryUnwindPlan(UnwindPlan &unwind_plan) {
unwind_plan.Clear();
unwind_plan.SetRegisterKind(eRegisterKindDWARF);
uint32_t sp_reg_num = dwarf_rsp;
uint32_t pc_reg_num = dwarf_rip;
UnwindPlan::RowSP row(new UnwindPlan::Row);
row->GetCFAValue().SetIsRegisterPlusOffset(sp_reg_num, 8);
row->SetRegisterLocationToAtCFAPlusOffset(pc_reg_num, -8, false);
row->SetRegisterLocationToIsCFAPlusOffset(sp_reg_num, 0, true);
unwind_plan.AppendRow(row);
unwind_plan.SetSourceName("x86_64 at-func-entry default");
unwind_plan.SetSourcedFromCompiler(eLazyBoolNo);
return true;
}
// This defines the CFA as rbp+16
// The saved pc is at CFA-8 (i.e. rbp+8)
// The saved rbp is at CFA-16 (i.e. rbp+0)
// The saved rsp is CFA+0
bool ABISysV_x86_64::CreateDefaultUnwindPlan(UnwindPlan &unwind_plan) {
unwind_plan.Clear();
unwind_plan.SetRegisterKind(eRegisterKindDWARF);
uint32_t fp_reg_num = dwarf_rbp;
uint32_t sp_reg_num = dwarf_rsp;
uint32_t pc_reg_num = dwarf_rip;
UnwindPlan::RowSP row(new UnwindPlan::Row);
const int32_t ptr_size = 8;
row->GetCFAValue().SetIsRegisterPlusOffset(dwarf_rbp, 2 * ptr_size);
row->SetOffset(0);
row->SetUnspecifiedRegistersAreUndefined(true);
row->SetRegisterLocationToAtCFAPlusOffset(fp_reg_num, ptr_size * -2, true);
row->SetRegisterLocationToAtCFAPlusOffset(pc_reg_num, ptr_size * -1, true);
row->SetRegisterLocationToIsCFAPlusOffset(sp_reg_num, 0, true);
unwind_plan.AppendRow(row);
unwind_plan.SetSourceName("x86_64 default unwind plan");
unwind_plan.SetSourcedFromCompiler(eLazyBoolNo);
unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo);
unwind_plan.SetUnwindPlanForSignalTrap(eLazyBoolNo);
return true;
}
bool ABISysV_x86_64::RegisterIsVolatile(const RegisterInfo *reg_info) {
return !RegisterIsCalleeSaved(reg_info);
}
// See "Register Usage" in the
// "System V Application Binary Interface"
// "AMD64 Architecture Processor Supplement" (or "x86-64(tm) Architecture
// Processor Supplement" in earlier revisions) (this doc is also commonly
// referred to as the x86-64/AMD64 psABI) Edited by Michael Matz, Jan Hubicka,
// Andreas Jaeger, and Mark Mitchell current version is 0.99.6 released
// 2012-07-02 at http://refspecs.linuxfoundation.org/elf/x86-64-abi-0.99.pdf
// It's being revised & updated at https://github.com/hjl-tools/x86-psABI/
bool ABISysV_x86_64::RegisterIsCalleeSaved(const RegisterInfo *reg_info) {
if (!reg_info)
return false;
assert(reg_info->name != nullptr && "unnamed register?");
std::string Name = std::string(reg_info->name);
bool IsCalleeSaved =
llvm::StringSwitch<bool>(Name)
.Cases("r12", "r13", "r14", "r15", "rbp", "ebp", "rbx", "ebx", true)
.Cases("rip", "eip", "rsp", "esp", "sp", "fp", "pc", true)
.Default(false);
return IsCalleeSaved;
}
uint32_t ABISysV_x86_64::GetGenericNum(llvm::StringRef name) {
return llvm::StringSwitch<uint32_t>(name)
.Case("rip", LLDB_REGNUM_GENERIC_PC)
.Case("rsp", LLDB_REGNUM_GENERIC_SP)
.Case("rbp", LLDB_REGNUM_GENERIC_FP)
.Case("rflags", LLDB_REGNUM_GENERIC_FLAGS)
// gdbserver uses eflags
.Case("eflags", LLDB_REGNUM_GENERIC_FLAGS)
.Case("rdi", LLDB_REGNUM_GENERIC_ARG1)
.Case("rsi", LLDB_REGNUM_GENERIC_ARG2)
.Case("rdx", LLDB_REGNUM_GENERIC_ARG3)
.Case("rcx", LLDB_REGNUM_GENERIC_ARG4)
.Case("r8", LLDB_REGNUM_GENERIC_ARG5)
.Case("r9", LLDB_REGNUM_GENERIC_ARG6)
.Default(LLDB_INVALID_REGNUM);
}
void ABISysV_x86_64::Initialize() {
PluginManager::RegisterPlugin(
GetPluginNameStatic(), "System V ABI for x86_64 targets", CreateInstance);
}
void ABISysV_x86_64::Terminate() {
PluginManager::UnregisterPlugin(CreateInstance);
}
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