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//===-- Scalar.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 "lldb/Utility/Scalar.h"
#include "lldb/Utility/DataBufferHeap.h"
#include "lldb/Utility/DataExtractor.h"
#include "lldb/Utility/Endian.h"
#include "lldb/Utility/Status.h"
#include "lldb/Utility/Stream.h"
#include "lldb/Utility/StreamString.h"
#include "lldb/lldb-types.h"
#include "llvm/ADT/APSInt.h"
#include "llvm/ADT/SmallString.h"
#include <cinttypes>
#include <cstdio>
using namespace lldb;
using namespace lldb_private;
using llvm::APFloat;
using llvm::APInt;
using llvm::APSInt;
Scalar::PromotionKey Scalar::GetPromoKey() const {
switch (m_type) {
case e_void:
return PromotionKey{e_void, 0, false};
case e_int:
return PromotionKey{e_int, m_integer.getBitWidth(), m_integer.isUnsigned()};
case e_float:
return GetFloatPromoKey(m_float.getSemantics());
}
llvm_unreachable("Unhandled category!");
}
Scalar::PromotionKey Scalar::GetFloatPromoKey(const llvm::fltSemantics &sem) {
static const llvm::fltSemantics *const order[] = {
&APFloat::IEEEsingle(), &APFloat::IEEEdouble(),
&APFloat::x87DoubleExtended()};
for (const auto &entry : llvm::enumerate(order)) {
if (entry.value() == &sem)
return PromotionKey{e_float, entry.index(), false};
}
llvm_unreachable("Unsupported semantics!");
}
// Promote to max type currently follows the ANSI C rule for type promotion in
// expressions.
Scalar::Type Scalar::PromoteToMaxType(Scalar &lhs, Scalar &rhs) {
const auto &Promote = [](Scalar &a, const Scalar &b) {
switch (b.GetType()) {
case e_void:
break;
case e_int:
a.IntegralPromote(b.m_integer.getBitWidth(), b.m_integer.isSigned());
break;
case e_float:
a.FloatPromote(b.m_float.getSemantics());
}
};
PromotionKey lhs_key = lhs.GetPromoKey();
PromotionKey rhs_key = rhs.GetPromoKey();
if (lhs_key > rhs_key)
Promote(rhs, lhs);
else if (rhs_key > lhs_key)
Promote(lhs, rhs);
// Make sure our type promotion worked as expected
if (lhs.GetPromoKey() == rhs.GetPromoKey())
return lhs.GetType(); // Return the resulting type
// Return the void type (zero) if we fail to promote either of the values.
return Scalar::e_void;
}
bool Scalar::GetData(DataExtractor &data, size_t limit_byte_size) const {
size_t byte_size = GetByteSize();
if (byte_size == 0) {
data.Clear();
return false;
}
auto buffer_up = std::make_unique<DataBufferHeap>(byte_size, 0);
GetBytes(buffer_up->GetData());
lldb::offset_t offset = 0;
if (limit_byte_size < byte_size) {
if (endian::InlHostByteOrder() == eByteOrderLittle) {
// On little endian systems if we want fewer bytes from the current
// type we just specify fewer bytes since the LSByte is first...
byte_size = limit_byte_size;
} else if (endian::InlHostByteOrder() == eByteOrderBig) {
// On big endian systems if we want fewer bytes from the current type
// have to advance our initial byte pointer and trim down the number of
// bytes since the MSByte is first
offset = byte_size - limit_byte_size;
byte_size = limit_byte_size;
}
}
data.SetData(std::move(buffer_up), offset, byte_size);
data.SetByteOrder(endian::InlHostByteOrder());
return true;
}
void Scalar::GetBytes(llvm::MutableArrayRef<uint8_t> storage) const {
assert(storage.size() >= GetByteSize());
const auto &store = [&](const llvm::APInt &val) {
StoreIntToMemory(val, storage.data(), (val.getBitWidth() + 7) / 8);
};
switch (m_type) {
case e_void:
break;
case e_int:
store(m_integer);
break;
case e_float:
store(m_float.bitcastToAPInt());
break;
}
}
size_t Scalar::GetByteSize() const {
switch (m_type) {
case e_void:
break;
case e_int:
return (m_integer.getBitWidth() / 8);
case e_float:
return m_float.bitcastToAPInt().getBitWidth() / 8;
}
return 0;
}
bool Scalar::IsZero() const {
switch (m_type) {
case e_void:
break;
case e_int:
return m_integer.isNullValue();
case e_float:
return m_float.isZero();
}
return false;
}
void Scalar::GetValue(Stream *s, bool show_type) const {
if (show_type)
s->Printf("(%s) ", GetTypeAsCString());
switch (m_type) {
case e_void:
break;
case e_int:
s->PutCString(m_integer.toString(10));
break;
case e_float:
llvm::SmallString<24> string;
m_float.toString(string);
s->PutCString(string);
break;
}
}
void Scalar::TruncOrExtendTo(uint16_t bits, bool sign) {
m_integer.setIsSigned(sign);
m_integer = m_integer.extOrTrunc(bits);
}
bool Scalar::IntegralPromote(uint16_t bits, bool sign) {
switch (m_type) {
case e_void:
case e_float:
break;
case e_int:
if (GetPromoKey() > PromotionKey(e_int, bits, !sign))
break;
m_integer = m_integer.extOrTrunc(bits);
m_integer.setIsSigned(sign);
return true;
}
return false;
}
bool Scalar::FloatPromote(const llvm::fltSemantics &semantics) {
bool success = false;
switch (m_type) {
case e_void:
break;
case e_int:
m_float = llvm::APFloat(semantics);
m_float.convertFromAPInt(m_integer, m_integer.isSigned(),
llvm::APFloat::rmNearestTiesToEven);
success = true;
break;
case e_float:
if (GetFloatPromoKey(semantics) < GetFloatPromoKey(m_float.getSemantics()))
break;
bool ignore;
success = true;
m_float.convert(semantics, llvm::APFloat::rmNearestTiesToEven, &ignore);
}
if (success)
m_type = e_float;
return success;
}
const char *Scalar::GetValueTypeAsCString(Scalar::Type type) {
switch (type) {
case e_void:
return "void";
case e_int:
return "int";
case e_float:
return "float";
}
return "???";
}
bool Scalar::IsSigned() const {
switch (m_type) {
case e_void:
return false;
case e_int:
return m_integer.isSigned();
case e_float:
return true;
}
llvm_unreachable("Unrecognized type!");
}
bool Scalar::MakeSigned() {
bool success = false;
switch (m_type) {
case e_void:
break;
case e_int:
m_integer.setIsSigned(true);
success = true;
break;
case e_float:
success = true;
break;
}
return success;
}
bool Scalar::MakeUnsigned() {
bool success = false;
switch (m_type) {
case e_void:
break;
case e_int:
m_integer.setIsUnsigned(true);
success = true;
break;
case e_float:
success = true;
break;
}
return success;
}
static llvm::APInt ToAPInt(const llvm::APFloat &f, unsigned bits,
bool is_unsigned) {
llvm::APSInt result(bits, is_unsigned);
bool isExact;
f.convertToInteger(result, llvm::APFloat::rmTowardZero, &isExact);
return std::move(result);
}
template <typename T> T Scalar::GetAs(T fail_value) const {
switch (m_type) {
case e_void:
break;
case e_int: {
APSInt ext = m_integer.extOrTrunc(sizeof(T) * 8);
if (ext.isSigned())
return ext.getSExtValue();
return ext.getZExtValue();
}
case e_float:
return ToAPInt(m_float, sizeof(T) * 8, std::is_unsigned<T>::value)
.getSExtValue();
}
return fail_value;
}
signed char Scalar::SChar(signed char fail_value) const {
return GetAs<signed char>(fail_value);
}
unsigned char Scalar::UChar(unsigned char fail_value) const {
return GetAs<unsigned char>(fail_value);
}
short Scalar::SShort(short fail_value) const {
return GetAs<short>(fail_value);
}
unsigned short Scalar::UShort(unsigned short fail_value) const {
return GetAs<unsigned short>(fail_value);
}
int Scalar::SInt(int fail_value) const { return GetAs<int>(fail_value); }
unsigned int Scalar::UInt(unsigned int fail_value) const {
return GetAs<unsigned int>(fail_value);
}
long Scalar::SLong(long fail_value) const { return GetAs<long>(fail_value); }
unsigned long Scalar::ULong(unsigned long fail_value) const {
return GetAs<unsigned long>(fail_value);
}
long long Scalar::SLongLong(long long fail_value) const {
return GetAs<long long>(fail_value);
}
unsigned long long Scalar::ULongLong(unsigned long long fail_value) const {
return GetAs<unsigned long long>(fail_value);
}
llvm::APInt Scalar::SInt128(const llvm::APInt &fail_value) const {
switch (m_type) {
case e_void:
break;
case e_int:
return m_integer;
case e_float:
return ToAPInt(m_float, 128, /*is_unsigned=*/false);
}
return fail_value;
}
llvm::APInt Scalar::UInt128(const llvm::APInt &fail_value) const {
switch (m_type) {
case e_void:
break;
case e_int:
return m_integer;
case e_float:
return ToAPInt(m_float, 128, /*is_unsigned=*/true);
}
return fail_value;
}
float Scalar::Float(float fail_value) const {
switch (m_type) {
case e_void:
break;
case e_int:
if (m_integer.isSigned())
return llvm::APIntOps::RoundSignedAPIntToFloat(m_integer);
return llvm::APIntOps::RoundAPIntToFloat(m_integer);
case e_float: {
APFloat result = m_float;
bool losesInfo;
result.convert(APFloat::IEEEsingle(), APFloat::rmNearestTiesToEven,
&losesInfo);
return result.convertToFloat();
}
}
return fail_value;
}
double Scalar::Double(double fail_value) const {
switch (m_type) {
case e_void:
break;
case e_int:
if (m_integer.isSigned())
return llvm::APIntOps::RoundSignedAPIntToDouble(m_integer);
return llvm::APIntOps::RoundAPIntToDouble(m_integer);
case e_float: {
APFloat result = m_float;
bool losesInfo;
result.convert(APFloat::IEEEdouble(), APFloat::rmNearestTiesToEven,
&losesInfo);
return result.convertToDouble();
}
}
return fail_value;
}
long double Scalar::LongDouble(long double fail_value) const {
/// No way to get more precision at the moment.
return static_cast<long double>(Double(fail_value));
}
Scalar &Scalar::operator+=(Scalar rhs) {
Scalar copy = *this;
if ((m_type = PromoteToMaxType(copy, rhs)) != Scalar::e_void) {
switch (m_type) {
case e_void:
break;
case e_int:
m_integer = copy.m_integer + rhs.m_integer;
break;
case e_float:
m_float = copy.m_float + rhs.m_float;
break;
}
}
return *this;
}
Scalar &Scalar::operator<<=(const Scalar &rhs) {
if (m_type == e_int && rhs.m_type == e_int)
static_cast<APInt &>(m_integer) <<= rhs.m_integer;
else
m_type = e_void;
return *this;
}
bool Scalar::ShiftRightLogical(const Scalar &rhs) {
if (m_type == e_int && rhs.m_type == e_int) {
m_integer = m_integer.lshr(rhs.m_integer);
return true;
}
m_type = e_void;
return false;
}
Scalar &Scalar::operator>>=(const Scalar &rhs) {
switch (m_type) {
case e_void:
case e_float:
m_type = e_void;
break;
case e_int:
switch (rhs.m_type) {
case e_void:
case e_float:
m_type = e_void;
break;
case e_int:
m_integer = m_integer.ashr(rhs.m_integer);
break;
}
break;
}
return *this;
}
Scalar &Scalar::operator&=(const Scalar &rhs) {
if (m_type == e_int && rhs.m_type == e_int)
m_integer &= rhs.m_integer;
else
m_type = e_void;
return *this;
}
bool Scalar::AbsoluteValue() {
switch (m_type) {
case e_void:
break;
case e_int:
if (m_integer.isNegative())
m_integer = -m_integer;
return true;
case e_float:
m_float.clearSign();
return true;
}
return false;
}
bool Scalar::UnaryNegate() {
switch (m_type) {
case e_void:
break;
case e_int:
m_integer = -m_integer;
return true;
case e_float:
m_float.changeSign();
return true;
}
return false;
}
bool Scalar::OnesComplement() {
if (m_type == e_int) {
m_integer = ~m_integer;
return true;
}
return false;
}
const Scalar lldb_private::operator+(const Scalar &lhs, const Scalar &rhs) {
Scalar result = lhs;
result += rhs;
return result;
}
const Scalar lldb_private::operator-(Scalar lhs, Scalar rhs) {
Scalar result;
if ((result.m_type = Scalar::PromoteToMaxType(lhs, rhs)) != Scalar::e_void) {
switch (result.m_type) {
case Scalar::e_void:
break;
case Scalar::e_int:
result.m_integer = lhs.m_integer - rhs.m_integer;
break;
case Scalar::e_float:
result.m_float = lhs.m_float - rhs.m_float;
break;
}
}
return result;
}
const Scalar lldb_private::operator/(Scalar lhs, Scalar rhs) {
Scalar result;
if ((result.m_type = Scalar::PromoteToMaxType(lhs, rhs)) != Scalar::e_void &&
!rhs.IsZero()) {
switch (result.m_type) {
case Scalar::e_void:
break;
case Scalar::e_int:
result.m_integer = lhs.m_integer / rhs.m_integer;
return result;
case Scalar::e_float:
result.m_float = lhs.m_float / rhs.m_float;
return result;
}
}
// For division only, the only way it should make it here is if a promotion
// failed, or if we are trying to do a divide by zero.
result.m_type = Scalar::e_void;
return result;
}
const Scalar lldb_private::operator*(Scalar lhs, Scalar rhs) {
Scalar result;
if ((result.m_type = Scalar::PromoteToMaxType(lhs, rhs)) != Scalar::e_void) {
switch (result.m_type) {
case Scalar::e_void:
break;
case Scalar::e_int:
result.m_integer = lhs.m_integer * rhs.m_integer;
break;
case Scalar::e_float:
result.m_float = lhs.m_float * rhs.m_float;
break;
}
}
return result;
}
const Scalar lldb_private::operator&(Scalar lhs, Scalar rhs) {
Scalar result;
if ((result.m_type = Scalar::PromoteToMaxType(lhs, rhs)) != Scalar::e_void) {
if (result.m_type == Scalar::e_int)
result.m_integer = lhs.m_integer & rhs.m_integer;
else
result.m_type = Scalar::e_void;
}
return result;
}
const Scalar lldb_private::operator|(Scalar lhs, Scalar rhs) {
Scalar result;
if ((result.m_type = Scalar::PromoteToMaxType(lhs, rhs)) != Scalar::e_void) {
if (result.m_type == Scalar::e_int)
result.m_integer = lhs.m_integer | rhs.m_integer;
else
result.m_type = Scalar::e_void;
}
return result;
}
const Scalar lldb_private::operator%(Scalar lhs, Scalar rhs) {
Scalar result;
if ((result.m_type = Scalar::PromoteToMaxType(lhs, rhs)) != Scalar::e_void) {
if (!rhs.IsZero() && result.m_type == Scalar::e_int) {
result.m_integer = lhs.m_integer % rhs.m_integer;
return result;
}
}
result.m_type = Scalar::e_void;
return result;
}
const Scalar lldb_private::operator^(Scalar lhs, Scalar rhs) {
Scalar result;
if ((result.m_type = Scalar::PromoteToMaxType(lhs, rhs)) != Scalar::e_void) {
if (result.m_type == Scalar::e_int)
result.m_integer = lhs.m_integer ^ rhs.m_integer;
else
result.m_type = Scalar::e_void;
}
return result;
}
const Scalar lldb_private::operator<<(const Scalar &lhs, const Scalar &rhs) {
Scalar result = lhs;
result <<= rhs;
return result;
}
const Scalar lldb_private::operator>>(const Scalar &lhs, const Scalar &rhs) {
Scalar result = lhs;
result >>= rhs;
return result;
}
Status Scalar::SetValueFromCString(const char *value_str, Encoding encoding,
size_t byte_size) {
Status error;
if (value_str == nullptr || value_str[0] == '\0') {
error.SetErrorString("Invalid c-string value string.");
return error;
}
switch (encoding) {
case eEncodingInvalid:
error.SetErrorString("Invalid encoding.");
break;
case eEncodingSint:
case eEncodingUint: {
llvm::StringRef str = value_str;
bool is_signed = encoding == eEncodingSint;
bool is_negative = is_signed && str.consume_front("-");
APInt integer;
if (str.getAsInteger(0, integer)) {
error.SetErrorStringWithFormatv(
"'{0}' is not a valid integer string value", value_str);
break;
}
bool fits;
if (is_signed) {
integer = integer.zext(integer.getBitWidth() + 1);
if (is_negative)
integer.negate();
fits = integer.isSignedIntN(byte_size * 8);
} else
fits = integer.isIntN(byte_size * 8);
if (!fits) {
error.SetErrorStringWithFormatv(
"value {0} is too large to fit in a {1} byte integer value",
value_str, byte_size);
break;
}
m_type = e_int;
m_integer =
APSInt(std::move(integer), !is_signed).extOrTrunc(8 * byte_size);
break;
}
case eEncodingIEEE754: {
// FIXME: It's not possible to unambiguously map a byte size to a floating
// point type. This function should be refactored to take an explicit
// semantics argument.
const llvm::fltSemantics &sem =
byte_size <= 4 ? APFloat::IEEEsingle()
: byte_size <= 8 ? APFloat::IEEEdouble()
: APFloat::x87DoubleExtended();
APFloat f(sem);
if (llvm::Expected<APFloat::opStatus> op =
f.convertFromString(value_str, APFloat::rmNearestTiesToEven)) {
m_type = e_float;
m_float = std::move(f);
} else
error = op.takeError();
break;
}
case eEncodingVector:
error.SetErrorString("vector encoding unsupported.");
break;
}
if (error.Fail())
m_type = e_void;
return error;
}
Status Scalar::SetValueFromData(const DataExtractor &data,
lldb::Encoding encoding, size_t byte_size) {
Status error;
switch (encoding) {
case lldb::eEncodingInvalid:
error.SetErrorString("invalid encoding");
break;
case lldb::eEncodingVector:
error.SetErrorString("vector encoding unsupported");
break;
case lldb::eEncodingUint:
case lldb::eEncodingSint: {
if (data.GetByteSize() < byte_size)
return Status("insufficient data");
m_type = e_int;
m_integer =
APSInt(APInt::getNullValue(8 * byte_size), encoding == eEncodingUint);
if (data.GetByteOrder() == endian::InlHostByteOrder()) {
llvm::LoadIntFromMemory(m_integer, data.GetDataStart(), byte_size);
} else {
std::vector<uint8_t> buffer(byte_size);
std::copy_n(data.GetDataStart(), byte_size, buffer.rbegin());
llvm::LoadIntFromMemory(m_integer, buffer.data(), byte_size);
}
break;
}
case lldb::eEncodingIEEE754: {
lldb::offset_t offset = 0;
if (byte_size == sizeof(float))
operator=(data.GetFloat(&offset));
else if (byte_size == sizeof(double))
operator=(data.GetDouble(&offset));
else if (byte_size == sizeof(long double))
operator=(data.GetLongDouble(&offset));
else
error.SetErrorStringWithFormat("unsupported float byte size: %" PRIu64 "",
static_cast<uint64_t>(byte_size));
} break;
}
return error;
}
bool Scalar::SignExtend(uint32_t sign_bit_pos) {
const uint32_t max_bit_pos = GetByteSize() * 8;
if (sign_bit_pos < max_bit_pos) {
switch (m_type) {
case Scalar::e_void:
case Scalar::e_float:
return false;
case Scalar::e_int:
if (max_bit_pos == sign_bit_pos)
return true;
else if (sign_bit_pos < (max_bit_pos - 1)) {
llvm::APInt sign_bit = llvm::APInt::getSignMask(sign_bit_pos + 1);
llvm::APInt bitwize_and = m_integer & sign_bit;
if (bitwize_and.getBoolValue()) {
llvm::APInt mask =
~(sign_bit) + llvm::APInt(m_integer.getBitWidth(), 1);
m_integer |= APSInt(std::move(mask), m_integer.isUnsigned());
}
return true;
}
break;
}
}
return false;
}
size_t Scalar::GetAsMemoryData(void *dst, size_t dst_len,
lldb::ByteOrder dst_byte_order,
Status &error) const {
// Get a data extractor that points to the native scalar data
DataExtractor data;
if (!GetData(data)) {
error.SetErrorString("invalid scalar value");
return 0;
}
const size_t src_len = data.GetByteSize();
// Prepare a memory buffer that contains some or all of the register value
const size_t bytes_copied =
data.CopyByteOrderedData(0, // src offset
src_len, // src length
dst, // dst buffer
dst_len, // dst length
dst_byte_order); // dst byte order
if (bytes_copied == 0)
error.SetErrorString("failed to copy data");
return bytes_copied;
}
bool Scalar::ExtractBitfield(uint32_t bit_size, uint32_t bit_offset) {
if (bit_size == 0)
return true;
switch (m_type) {
case Scalar::e_void:
case Scalar::e_float:
break;
case Scalar::e_int:
m_integer >>= bit_offset;
m_integer = m_integer.extOrTrunc(bit_size).extOrTrunc(8 * GetByteSize());
return true;
}
return false;
}
bool lldb_private::operator==(Scalar lhs, Scalar rhs) {
// If either entry is void then we can just compare the types
if (lhs.m_type == Scalar::e_void || rhs.m_type == Scalar::e_void)
return lhs.m_type == rhs.m_type;
llvm::APFloat::cmpResult result;
switch (Scalar::PromoteToMaxType(lhs, rhs)) {
case Scalar::e_void:
break;
case Scalar::e_int:
return lhs.m_integer == rhs.m_integer;
case Scalar::e_float:
result = lhs.m_float.compare(rhs.m_float);
if (result == llvm::APFloat::cmpEqual)
return true;
}
return false;
}
bool lldb_private::operator!=(const Scalar &lhs, const Scalar &rhs) {
return !(lhs == rhs);
}
bool lldb_private::operator<(Scalar lhs, Scalar rhs) {
if (lhs.m_type == Scalar::e_void || rhs.m_type == Scalar::e_void)
return false;
llvm::APFloat::cmpResult result;
switch (Scalar::PromoteToMaxType(lhs, rhs)) {
case Scalar::e_void:
break;
case Scalar::e_int:
return lhs.m_integer < rhs.m_integer;
case Scalar::e_float:
result = lhs.m_float.compare(rhs.m_float);
if (result == llvm::APFloat::cmpLessThan)
return true;
}
return false;
}
bool lldb_private::operator<=(const Scalar &lhs, const Scalar &rhs) {
return !(rhs < lhs);
}
bool lldb_private::operator>(const Scalar &lhs, const Scalar &rhs) {
return rhs < lhs;
}
bool lldb_private::operator>=(const Scalar &lhs, const Scalar &rhs) {
return !(lhs < rhs);
}
bool Scalar::ClearBit(uint32_t bit) {
switch (m_type) {
case e_void:
break;
case e_int:
m_integer.clearBit(bit);
return true;
case e_float:
break;
}
return false;
}
bool Scalar::SetBit(uint32_t bit) {
switch (m_type) {
case e_void:
break;
case e_int:
m_integer.setBit(bit);
return true;
case e_float:
break;
}
return false;
}
llvm::raw_ostream &lldb_private::operator<<(llvm::raw_ostream &os, const Scalar &scalar) {
StreamString s;
scalar.GetValue(&s, /*show_type*/ true);
return os << s.GetString();
}