1//===-- Scalar.h ------------------------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef LLDB_UTILITY_SCALAR_H
10#define LLDB_UTILITY_SCALAR_H
11
12#include "lldb/Utility/LLDBAssert.h"
13#include "lldb/Utility/Status.h"
14#include "lldb/lldb-enumerations.h"
15#include "lldb/lldb-private-types.h"
16#include "llvm/ADT/APFloat.h"
17#include "llvm/ADT/APSInt.h"
18#include <cstddef>
19#include <cstdint>
20#include <utility>
21
22namespace lldb_private {
23
24class DataExtractor;
25class Stream;
26
27#define NUM_OF_WORDS_INT128 2
28#define BITWIDTH_INT128 128
29
30// A class designed to hold onto values and their corresponding types.
31// Operators are defined and Scalar objects will correctly promote their types
32// and values before performing these operations. Type promotion currently
33// follows the ANSI C type promotion rules.
34class Scalar {
35 template<typename T>
36 static llvm::APSInt MakeAPSInt(T v) {
37 static_assert(std::is_integral<T>::value, "");
38 static_assert(sizeof(T) <= sizeof(uint64_t), "Conversion loses precision!");
39 return llvm::APSInt(
40 llvm::APInt(sizeof(T) * 8, uint64_t(v), std::is_signed<T>::value),
41 std::is_unsigned<T>::value);
42 }
43
44public:
45 enum Type {
46 e_void = 0,
47 e_int,
48 e_float,
49 };
50
51 // Constructors and Destructors
52 Scalar() : m_type(e_void), m_float(0.0f) {}
53 Scalar(int v) : m_type(e_int), m_integer(MakeAPSInt(v)), m_float(0.0f) {}
54 Scalar(unsigned int v)
55 : m_type(e_int), m_integer(MakeAPSInt(v)), m_float(0.0f) {}
56 Scalar(long v) : m_type(e_int), m_integer(MakeAPSInt(v)), m_float(0.0f) {}
57 Scalar(unsigned long v)
58 : m_type(e_int), m_integer(MakeAPSInt(v)), m_float(0.0f) {}
59 Scalar(long long v)
60 : m_type(e_int), m_integer(MakeAPSInt(v)), m_float(0.0f) {}
61 Scalar(unsigned long long v)
62 : m_type(e_int), m_integer(MakeAPSInt(v)), m_float(0.0f) {}
63 Scalar(float v) : m_type(e_float), m_float(v) {}
64 Scalar(double v) : m_type(e_float), m_float(v) {}
65 Scalar(long double v) : m_type(e_float), m_float(double(v)) {
66 bool ignore;
67 m_float.convert(llvm::APFloat::x87DoubleExtended(),
68 llvm::APFloat::rmNearestTiesToEven, &ignore);
69 }
70 Scalar(llvm::APInt v)
71 : m_type(e_int), m_integer(std::move(v), false), m_float(0.0f) {}
72 Scalar(llvm::APSInt v)
73 : m_type(e_int), m_integer(std::move(v)), m_float(0.0f) {}
74
75 bool SignExtend(uint32_t bit_pos);
76
77 bool ExtractBitfield(uint32_t bit_size, uint32_t bit_offset);
78
79 bool SetBit(uint32_t bit);
80
81 bool ClearBit(uint32_t bit);
82
83 /// Store the binary representation of this value into the given storage.
84 /// Exactly GetByteSize() bytes will be stored, and the buffer must be large
85 /// enough to hold this data.
86 void GetBytes(llvm::MutableArrayRef<uint8_t> storage) const;
87
88 size_t GetByteSize() const;
89
90 bool GetData(DataExtractor &data, size_t limit_byte_size = UINT32_MAX) const;
91
92 size_t GetAsMemoryData(void *dst, size_t dst_len,
93 lldb::ByteOrder dst_byte_order, Status &error) const;
94
95 bool IsZero() const;
96
97 void Clear() {
98 m_type = e_void;
99 m_integer.clearAllBits();
100 }
101
102 const char *GetTypeAsCString() const { return GetValueTypeAsCString(m_type); }
103
104 void GetValue(Stream *s, bool show_type) const;
105
106 bool IsValid() const { return (m_type >= e_int) && (m_type <= e_float); }
107
108 /// Convert to an integer with \p bits and the given signedness.
109 void TruncOrExtendTo(uint16_t bits, bool sign);
110
111 bool IntegralPromote(uint16_t bits, bool sign);
112 bool FloatPromote(const llvm::fltSemantics &semantics);
113
114 bool IsSigned() const;
115 bool MakeSigned();
116
117 bool MakeUnsigned();
118
119 static const char *GetValueTypeAsCString(Scalar::Type value_type);
120
121 // All operators can benefits from the implicit conversions that will happen
122 // automagically by the compiler, so no temporary objects will need to be
123 // created. As a result, we currently don't need a variety of overloaded set
124 // value accessors.
125 Scalar &operator+=(Scalar rhs);
126 Scalar &operator<<=(const Scalar &rhs); // Shift left
127 Scalar &operator>>=(const Scalar &rhs); // Shift right (arithmetic)
128 Scalar &operator&=(const Scalar &rhs);
129
130 // Shifts the current value to the right without maintaining the current sign
131 // of the value (if it is signed).
132 bool ShiftRightLogical(const Scalar &rhs); // Returns true on success
133
134 // Takes the absolute value of the current value if it is signed, else the
135 // value remains unchanged. Returns false if the contained value has a void
136 // type.
137 bool AbsoluteValue(); // Returns true on success
138 // Negates the current value (even for unsigned values). Returns false if the
139 // contained value has a void type.
140 bool UnaryNegate(); // Returns true on success
141 // Inverts all bits in the current value as long as it isn't void or a
142 // float/double/long double type. Returns false if the contained value has a
143 // void/float/double/long double type, else the value is inverted and true is
144 // returned.
145 bool OnesComplement(); // Returns true on success
146
147 // Access the type of the current value.
148 Scalar::Type GetType() const { return m_type; }
149
150 // Returns a casted value of the current contained data without modifying the
151 // current value. FAIL_VALUE will be returned if the type of the value is
152 // void or invalid.
153 int SInt(int fail_value = 0) const;
154
155 unsigned char UChar(unsigned char fail_value = 0) const;
156
157 signed char SChar(signed char fail_value = 0) const;
158
159 unsigned short UShort(unsigned short fail_value = 0) const;
160
161 short SShort(short fail_value = 0) const;
162
163 unsigned int UInt(unsigned int fail_value = 0) const;
164
165 long SLong(long fail_value = 0) const;
166
167 unsigned long ULong(unsigned long fail_value = 0) const;
168
169 long long SLongLong(long long fail_value = 0) const;
170
171 unsigned long long ULongLong(unsigned long long fail_value = 0) const;
172
173 llvm::APInt SInt128(const llvm::APInt &fail_value) const;
174
175 llvm::APInt UInt128(const llvm::APInt &fail_value) const;
176
177 float Float(float fail_value = 0.0f) const;
178
179 double Double(double fail_value = 0.0) const;
180
181 long double LongDouble(long double fail_value = 0.0) const;
182
183 Status SetValueFromCString(const char *s, lldb::Encoding encoding,
184 size_t byte_size);
185
186 Status SetValueFromData(const DataExtractor &data, lldb::Encoding encoding,
187 size_t byte_size);
188
189protected:
190 Scalar::Type m_type;
191 llvm::APSInt m_integer;
192 llvm::APFloat m_float;
193
194 template <typename T> T GetAs(T fail_value) const;
195
196 static Type PromoteToMaxType(Scalar &lhs, Scalar &rhs);
197
198 using PromotionKey = std::tuple<Type, unsigned, bool>;
199 PromotionKey GetPromoKey() const;
200
201 static PromotionKey GetFloatPromoKey(const llvm::fltSemantics &semantics);
202
203private:
204 friend const Scalar operator+(const Scalar &lhs, const Scalar &rhs);
205 friend const Scalar operator-(Scalar lhs, Scalar rhs);
206 friend const Scalar operator/(Scalar lhs, Scalar rhs);
207 friend const Scalar operator*(Scalar lhs, Scalar rhs);
208 friend const Scalar operator&(Scalar lhs, Scalar rhs);
209 friend const Scalar operator|(Scalar lhs, Scalar rhs);
210 friend const Scalar operator%(Scalar lhs, Scalar rhs);
211 friend const Scalar operator^(Scalar lhs, Scalar rhs);
212 friend const Scalar operator<<(const Scalar &lhs, const Scalar &rhs);
213 friend const Scalar operator>>(const Scalar &lhs, const Scalar &rhs);
214 friend bool operator==(Scalar lhs, Scalar rhs);
215 friend bool operator!=(const Scalar &lhs, const Scalar &rhs);
216 friend bool operator<(Scalar lhs, Scalar rhs);
217 friend bool operator<=(const Scalar &lhs, const Scalar &rhs);
218 friend bool operator>(const Scalar &lhs, const Scalar &rhs);
219 friend bool operator>=(const Scalar &lhs, const Scalar &rhs);
220};
221
222// Split out the operators into a format where the compiler will be able to
223// implicitly convert numbers into Scalar objects.
224//
225// This allows code like:
226// Scalar two(2);
227// Scalar four = two * 2;
228// Scalar eight = 2 * four; // This would cause an error if the
229// // operator* was implemented as a
230// // member function.
231// SEE:
232// Item 19 of "Effective C++ Second Edition" by Scott Meyers
233// Differentiate among members functions, non-member functions, and
234// friend functions
235const Scalar operator+(const Scalar &lhs, const Scalar &rhs);
236const Scalar operator-(Scalar lhs, Scalar rhs);
237const Scalar operator/(Scalar lhs, Scalar rhs);
238const Scalar operator*(Scalar lhs, Scalar rhs);
239const Scalar operator&(Scalar lhs, Scalar rhs);
240const Scalar operator|(Scalar lhs, Scalar rhs);
241const Scalar operator%(Scalar lhs, Scalar rhs);
242const Scalar operator^(Scalar lhs, Scalar rhs);
243const Scalar operator<<(const Scalar &lhs, const Scalar &rhs);
244const Scalar operator>>(const Scalar &lhs, const Scalar &rhs);
245bool operator==(Scalar lhs, Scalar rhs);
246bool operator!=(const Scalar &lhs, const Scalar &rhs);
247bool operator<(Scalar lhs, Scalar rhs);
248bool operator<=(const Scalar &lhs, const Scalar &rhs);
249bool operator>(const Scalar &lhs, const Scalar &rhs);
250bool operator>=(const Scalar &lhs, const Scalar &rhs);
251
252llvm::raw_ostream &operator<<(llvm::raw_ostream &os, const Scalar &scalar);
253
254} // namespace lldb_private
255
256#endif // LLDB_UTILITY_SCALAR_H
257