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be1294de9dd93ae02002bd1aa4b4a8d62e562c21
clang-p2996/lldb/source/Plugins/ABI/X86/ABISysV_x86_64.cpp
Pavel Labath c34698a811 [lldb] Rename Logging.h to LLDBLog.h and clean up includes 
Most of our code was including Log.h even though that is not where the
"lldb" log channel is defined (Log.h defines the generic logging
infrastructure). This worked because Log.h included Logging.h, even
though it should.

After the recent refactor, it became impossible the two files include
each other in this direction (the opposite inclusion is needed), so this
patch removes the workaround that was put in place and cleans up all
files to include the right thing. It also renames the file to LLDBLog to
better reflect its purpose.
2022-02-03 14:47:01 +01:00

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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/ADT/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 <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();
llvm::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 {
llvm::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
llvm::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 {
llvm::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) {
llvm::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);
llvm::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;
llvm::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;
if (return_compiler_type.GetTypeSystem()->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();
DataBufferSP 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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