xref: /llvm-project/clang/lib/AST/ByteCode/Boolean.h (revision 12ca72ba7f11fb880794a37cffdea5f47e3062f4)
1 //===--- Boolean.h - Wrapper for boolean types for the VM -------*- 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 LLVM_CLANG_AST_INTERP_BOOLEAN_H
10 #define LLVM_CLANG_AST_INTERP_BOOLEAN_H
11 
12 #include "Integral.h"
13 #include "clang/AST/APValue.h"
14 #include "clang/AST/ComparisonCategories.h"
15 #include "llvm/ADT/APSInt.h"
16 #include "llvm/Support/MathExtras.h"
17 #include "llvm/Support/raw_ostream.h"
18 #include <cstddef>
19 #include <cstdint>
20 
21 namespace clang {
22 namespace interp {
23 
24 /// Wrapper around boolean types.
25 class Boolean final {
26 private:
27   /// Underlying boolean.
28   bool V;
29 
30 public:
31   /// Zero-initializes a boolean.
32   Boolean() : V(false) {}
33   Boolean(const llvm::APSInt &I) : V(!I.isZero()) {}
34   explicit Boolean(bool V) : V(V) {}
35 
36   bool operator<(Boolean RHS) const { return V < RHS.V; }
37   bool operator>(Boolean RHS) const { return V > RHS.V; }
38   bool operator<=(Boolean RHS) const { return V <= RHS.V; }
39   bool operator>=(Boolean RHS) const { return V >= RHS.V; }
40   bool operator==(Boolean RHS) const { return V == RHS.V; }
41   bool operator!=(Boolean RHS) const { return V != RHS.V; }
42 
43   bool operator>(unsigned RHS) const { return static_cast<unsigned>(V) > RHS; }
44 
45   Boolean operator-() const { return Boolean(V); }
46   Boolean operator-(const Boolean &Other) const { return Boolean(V - Other.V); }
47   Boolean operator~() const { return Boolean(true); }
48   Boolean operator!() const { return Boolean(!V); }
49 
50   template <typename Ty, typename = std::enable_if_t<std::is_integral_v<Ty>>>
51   explicit operator Ty() const {
52     return V;
53   }
54 
55   APSInt toAPSInt() const {
56     return APSInt(APInt(1, static_cast<uint64_t>(V), false), true);
57   }
58   APSInt toAPSInt(unsigned NumBits) const {
59     return APSInt(toAPSInt().zextOrTrunc(NumBits), true);
60   }
61   APValue toAPValue(const ASTContext &) const { return APValue(toAPSInt()); }
62 
63   Boolean toUnsigned() const { return *this; }
64 
65   constexpr static unsigned bitWidth() { return 1; }
66   bool isZero() const { return !V; }
67   bool isMin() const { return isZero(); }
68 
69   constexpr static bool isMinusOne() { return false; }
70 
71   constexpr static bool isSigned() { return false; }
72 
73   constexpr static bool isNegative() { return false; }
74   constexpr static bool isPositive() { return !isNegative(); }
75 
76   ComparisonCategoryResult compare(const Boolean &RHS) const {
77     return Compare(V, RHS.V);
78   }
79 
80   unsigned countLeadingZeros() const { return V ? 0 : 1; }
81 
82   Boolean truncate(unsigned TruncBits) const { return *this; }
83 
84   static Boolean bitcastFromMemory(const std::byte *Buff, unsigned BitWidth) {
85     // Just load the first byte.
86     bool Val = static_cast<bool>(*Buff);
87     return Boolean(Val);
88   }
89 
90   void bitcastToMemory(std::byte *Buff) { std::memcpy(Buff, &V, sizeof(V)); }
91 
92   void print(llvm::raw_ostream &OS) const { OS << (V ? "true" : "false"); }
93   std::string toDiagnosticString(const ASTContext &Ctx) const {
94     std::string NameStr;
95     llvm::raw_string_ostream OS(NameStr);
96     print(OS);
97     return NameStr;
98   }
99 
100   static Boolean min(unsigned NumBits) { return Boolean(false); }
101   static Boolean max(unsigned NumBits) { return Boolean(true); }
102 
103   template <typename T> static Boolean from(T Value) {
104     if constexpr (std::is_integral<T>::value)
105       return Boolean(Value != 0);
106     return Boolean(static_cast<decltype(Boolean::V)>(Value) != 0);
107   }
108 
109   template <unsigned SrcBits, bool SrcSign>
110   static std::enable_if_t<SrcBits != 0, Boolean>
111   from(Integral<SrcBits, SrcSign> Value) {
112     return Boolean(!Value.isZero());
113   }
114 
115   static Boolean zero() { return from(false); }
116 
117   template <typename T> static Boolean from(T Value, unsigned NumBits) {
118     return Boolean(Value);
119   }
120 
121   static bool inRange(int64_t Value, unsigned NumBits) {
122     return Value == 0 || Value == 1;
123   }
124 
125   static bool increment(Boolean A, Boolean *R) {
126     *R = Boolean(true);
127     return false;
128   }
129 
130   static bool decrement(Boolean A, Boolean *R) {
131     llvm_unreachable("Cannot decrement booleans");
132   }
133 
134   static bool add(Boolean A, Boolean B, unsigned OpBits, Boolean *R) {
135     *R = Boolean(A.V || B.V);
136     return false;
137   }
138 
139   static bool sub(Boolean A, Boolean B, unsigned OpBits, Boolean *R) {
140     *R = Boolean(A.V ^ B.V);
141     return false;
142   }
143 
144   static bool mul(Boolean A, Boolean B, unsigned OpBits, Boolean *R) {
145     *R = Boolean(A.V && B.V);
146     return false;
147   }
148 
149   static bool inv(Boolean A, Boolean *R) {
150     *R = Boolean(!A.V);
151     return false;
152   }
153 
154   static bool neg(Boolean A, Boolean *R) {
155     *R = Boolean(A.V);
156     return false;
157   }
158 };
159 
160 inline llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Boolean &B) {
161   B.print(OS);
162   return OS;
163 }
164 
165 } // namespace interp
166 } // namespace clang
167 
168 #endif
169