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//===-- Scalar.h ------------------------------------------------*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
#ifndef LLDB_UTILITY_SCALAR_H
#define LLDB_UTILITY_SCALAR_H
#include "lldb/Utility/LLDBAssert.h"
#include "lldb/Utility/Status.h"
#include "lldb/lldb-enumerations.h"
#include "lldb/lldb-private-types.h"
#include "llvm/ADT/APFloat.h"
#include "llvm/ADT/APSInt.h"
#include <cstddef>
#include <cstdint>
#include <utility>
namespace lldb_private {
class DataExtractor;
class Stream;
#define NUM_OF_WORDS_INT128 2
#define BITWIDTH_INT128 128
// A class designed to hold onto values and their corresponding types.
// Operators are defined and Scalar objects will correctly promote their types
// and values before performing these operations. Type promotion currently
// follows the ANSI C type promotion rules.
class Scalar {
template<typename T>
static llvm::APSInt MakeAPSInt(T v) {
static_assert(std::is_integral<T>::value, "");
static_assert(sizeof(T) <= sizeof(uint64_t), "Conversion loses precision!");
return llvm::APSInt(
llvm::APInt(sizeof(T) * 8, uint64_t(v), std::is_signed<T>::value),
std::is_unsigned<T>::value);
}
public:
enum Type {
e_void = 0,
e_int,
e_float,
};
// Constructors and Destructors
Scalar() : m_type(e_void), m_float(0.0f) {}
Scalar(int v) : m_type(e_int), m_integer(MakeAPSInt(v)), m_float(0.0f) {}
Scalar(unsigned int v)
: m_type(e_int), m_integer(MakeAPSInt(v)), m_float(0.0f) {}
Scalar(long v) : m_type(e_int), m_integer(MakeAPSInt(v)), m_float(0.0f) {}
Scalar(unsigned long v)
: m_type(e_int), m_integer(MakeAPSInt(v)), m_float(0.0f) {}
Scalar(long long v)
: m_type(e_int), m_integer(MakeAPSInt(v)), m_float(0.0f) {}
Scalar(unsigned long long v)
: m_type(e_int), m_integer(MakeAPSInt(v)), m_float(0.0f) {}
Scalar(float v) : m_type(e_float), m_float(v) {}
Scalar(double v) : m_type(e_float), m_float(v) {}
Scalar(long double v) : m_type(e_float), m_float(double(v)) {
bool ignore;
m_float.convert(llvm::APFloat::x87DoubleExtended(),
llvm::APFloat::rmNearestTiesToEven, &ignore);
}
Scalar(llvm::APInt v)
: m_type(e_int), m_integer(std::move(v), false), m_float(0.0f) {}
Scalar(llvm::APSInt v)
: m_type(e_int), m_integer(std::move(v)), m_float(0.0f) {}
bool SignExtend(uint32_t bit_pos);
bool ExtractBitfield(uint32_t bit_size, uint32_t bit_offset);
bool SetBit(uint32_t bit);
bool ClearBit(uint32_t bit);
/// Store the binary representation of this value into the given storage.
/// Exactly GetByteSize() bytes will be stored, and the buffer must be large
/// enough to hold this data.
void GetBytes(llvm::MutableArrayRef<uint8_t> storage) const;
size_t GetByteSize() const;
bool GetData(DataExtractor &data, size_t limit_byte_size = UINT32_MAX) const;
size_t GetAsMemoryData(void *dst, size_t dst_len,
lldb::ByteOrder dst_byte_order, Status &error) const;
bool IsZero() const;
void Clear() {
m_type = e_void;
m_integer.clearAllBits();
}
const char *GetTypeAsCString() const { return GetValueTypeAsCString(m_type); }
void GetValue(Stream *s, bool show_type) const;
bool IsValid() const { return (m_type >= e_int) && (m_type <= e_float); }
/// Convert to an integer with \p bits and the given signedness.
void TruncOrExtendTo(uint16_t bits, bool sign);
bool IntegralPromote(uint16_t bits, bool sign);
bool FloatPromote(const llvm::fltSemantics &semantics);
bool IsSigned() const;
bool MakeSigned();
bool MakeUnsigned();
static const char *GetValueTypeAsCString(Scalar::Type value_type);
// All operators can benefits from the implicit conversions that will happen
// automagically by the compiler, so no temporary objects will need to be
// created. As a result, we currently don't need a variety of overloaded set
// value accessors.
Scalar &operator+=(Scalar rhs);
Scalar &operator<<=(const Scalar &rhs); // Shift left
Scalar &operator>>=(const Scalar &rhs); // Shift right (arithmetic)
Scalar &operator&=(const Scalar &rhs);
// Shifts the current value to the right without maintaining the current sign
// of the value (if it is signed).
bool ShiftRightLogical(const Scalar &rhs); // Returns true on success
// Takes the absolute value of the current value if it is signed, else the
// value remains unchanged. Returns false if the contained value has a void
// type.
bool AbsoluteValue(); // Returns true on success
// Negates the current value (even for unsigned values). Returns false if the
// contained value has a void type.
bool UnaryNegate(); // Returns true on success
// Inverts all bits in the current value as long as it isn't void or a
// float/double/long double type. Returns false if the contained value has a
// void/float/double/long double type, else the value is inverted and true is
// returned.
bool OnesComplement(); // Returns true on success
// Access the type of the current value.
Scalar::Type GetType() const { return m_type; }
// Returns a casted value of the current contained data without modifying the
// current value. FAIL_VALUE will be returned if the type of the value is
// void or invalid.
int SInt(int fail_value = 0) const;
unsigned char UChar(unsigned char fail_value = 0) const;
signed char SChar(signed char fail_value = 0) const;
unsigned short UShort(unsigned short fail_value = 0) const;
short SShort(short fail_value = 0) const;
unsigned int UInt(unsigned int fail_value = 0) const;
long SLong(long fail_value = 0) const;
unsigned long ULong(unsigned long fail_value = 0) const;
long long SLongLong(long long fail_value = 0) const;
unsigned long long ULongLong(unsigned long long fail_value = 0) const;
llvm::APInt SInt128(const llvm::APInt &fail_value) const;
llvm::APInt UInt128(const llvm::APInt &fail_value) const;
float Float(float fail_value = 0.0f) const;
double Double(double fail_value = 0.0) const;
long double LongDouble(long double fail_value = 0.0) const;
Status SetValueFromCString(const char *s, lldb::Encoding encoding,
size_t byte_size);
Status SetValueFromData(const DataExtractor &data, lldb::Encoding encoding,
size_t byte_size);
protected:
Scalar::Type m_type;
llvm::APSInt m_integer;
llvm::APFloat m_float;
template <typename T> T GetAs(T fail_value) const;
static Type PromoteToMaxType(Scalar &lhs, Scalar &rhs);
using PromotionKey = std::tuple<Type, unsigned, bool>;
PromotionKey GetPromoKey() const;
static PromotionKey GetFloatPromoKey(const llvm::fltSemantics &semantics);
private:
friend const Scalar operator+(const Scalar &lhs, const Scalar &rhs);
friend const Scalar operator-(Scalar lhs, Scalar rhs);
friend const Scalar operator/(Scalar lhs, Scalar rhs);
friend const Scalar operator*(Scalar lhs, Scalar rhs);
friend const Scalar operator&(Scalar lhs, Scalar rhs);
friend const Scalar operator|(Scalar lhs, Scalar rhs);
friend const Scalar operator%(Scalar lhs, Scalar rhs);
friend const Scalar operator^(Scalar lhs, Scalar rhs);
friend const Scalar operator<<(const Scalar &lhs, const Scalar &rhs);
friend const Scalar operator>>(const Scalar &lhs, const Scalar &rhs);
friend bool operator==(Scalar lhs, Scalar rhs);
friend bool operator!=(const Scalar &lhs, const Scalar &rhs);
friend bool operator<(Scalar lhs, Scalar rhs);
friend bool operator<=(const Scalar &lhs, const Scalar &rhs);
friend bool operator>(const Scalar &lhs, const Scalar &rhs);
friend bool operator>=(const Scalar &lhs, const Scalar &rhs);
};
// Split out the operators into a format where the compiler will be able to
// implicitly convert numbers into Scalar objects.
//
// This allows code like:
// Scalar two(2);
// Scalar four = two * 2;
// Scalar eight = 2 * four; // This would cause an error if the
// // operator* was implemented as a
// // member function.
// SEE:
// Item 19 of "Effective C++ Second Edition" by Scott Meyers
// Differentiate among members functions, non-member functions, and
// friend functions
const Scalar operator+(const Scalar &lhs, const Scalar &rhs);
const Scalar operator-(Scalar lhs, Scalar rhs);
const Scalar operator/(Scalar lhs, Scalar rhs);
const Scalar operator*(Scalar lhs, Scalar rhs);
const Scalar operator&(Scalar lhs, Scalar rhs);
const Scalar operator|(Scalar lhs, Scalar rhs);
const Scalar operator%(Scalar lhs, Scalar rhs);
const Scalar operator^(Scalar lhs, Scalar rhs);
const Scalar operator<<(const Scalar &lhs, const Scalar &rhs);
const Scalar operator>>(const Scalar &lhs, const Scalar &rhs);
bool operator==(Scalar lhs, Scalar rhs);
bool operator!=(const Scalar &lhs, const Scalar &rhs);
bool operator<(Scalar lhs, Scalar rhs);
bool operator<=(const Scalar &lhs, const Scalar &rhs);
bool operator>(const Scalar &lhs, const Scalar &rhs);
bool operator>=(const Scalar &lhs, const Scalar &rhs);
llvm::raw_ostream &operator<<(llvm::raw_ostream &os, const Scalar &scalar);
} // namespace lldb_private
#endif // LLDB_UTILITY_SCALAR_H