1 //===- AttributeImpl.h - Attribute Internals --------------------*- 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 /// \file 10 /// This file defines various helper methods and classes used by 11 /// LLVMContextImpl for creating and managing attributes. 12 /// 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_LIB_IR_ATTRIBUTEIMPL_H 16 #define LLVM_LIB_IR_ATTRIBUTEIMPL_H 17 18 #include "llvm/ADT/ArrayRef.h" 19 #include "llvm/ADT/DenseMap.h" 20 #include "llvm/ADT/FoldingSet.h" 21 #include "llvm/ADT/StringRef.h" 22 #include "llvm/IR/Attributes.h" 23 #include "llvm/Support/TrailingObjects.h" 24 #include <cassert> 25 #include <cstddef> 26 #include <cstdint> 27 #include <string> 28 #include <utility> 29 30 namespace llvm { 31 32 class LLVMContext; 33 class Type; 34 35 //===----------------------------------------------------------------------===// 36 /// \class 37 /// This class represents a single, uniqued attribute. That attribute 38 /// could be a single enum, a tuple, or a string. 39 class AttributeImpl : public FoldingSetNode { 40 unsigned char KindID; ///< Holds the AttrEntryKind of the attribute 41 42 protected: 43 enum AttrEntryKind { 44 EnumAttrEntry, 45 IntAttrEntry, 46 StringAttrEntry, 47 TypeAttrEntry, 48 }; 49 50 AttributeImpl(AttrEntryKind KindID) : KindID(KindID) {} 51 52 public: 53 // AttributesImpl is uniqued, these should not be available. 54 AttributeImpl(const AttributeImpl &) = delete; 55 AttributeImpl &operator=(const AttributeImpl &) = delete; 56 57 bool isEnumAttribute() const { return KindID == EnumAttrEntry; } 58 bool isIntAttribute() const { return KindID == IntAttrEntry; } 59 bool isStringAttribute() const { return KindID == StringAttrEntry; } 60 bool isTypeAttribute() const { return KindID == TypeAttrEntry; } 61 62 bool hasAttribute(Attribute::AttrKind A) const; 63 bool hasAttribute(StringRef Kind) const; 64 65 Attribute::AttrKind getKindAsEnum() const; 66 uint64_t getValueAsInt() const; 67 bool getValueAsBool() const; 68 69 StringRef getKindAsString() const; 70 StringRef getValueAsString() const; 71 72 Type *getValueAsType() const; 73 74 /// Used when sorting the attributes. 75 bool operator<(const AttributeImpl &AI) const; 76 77 void Profile(FoldingSetNodeID &ID) const { 78 if (isEnumAttribute()) 79 Profile(ID, getKindAsEnum(), static_cast<uint64_t>(0)); 80 else if (isIntAttribute()) 81 Profile(ID, getKindAsEnum(), getValueAsInt()); 82 else if (isStringAttribute()) 83 Profile(ID, getKindAsString(), getValueAsString()); 84 else 85 Profile(ID, getKindAsEnum(), getValueAsType()); 86 } 87 88 static void Profile(FoldingSetNodeID &ID, Attribute::AttrKind Kind, 89 uint64_t Val) { 90 ID.AddInteger(Kind); 91 if (Val) ID.AddInteger(Val); 92 } 93 94 static void Profile(FoldingSetNodeID &ID, StringRef Kind, StringRef Values) { 95 ID.AddString(Kind); 96 if (!Values.empty()) ID.AddString(Values); 97 } 98 99 static void Profile(FoldingSetNodeID &ID, Attribute::AttrKind Kind, 100 Type *Ty) { 101 ID.AddInteger(Kind); 102 ID.AddPointer(Ty); 103 } 104 }; 105 106 static_assert(std::is_trivially_destructible<AttributeImpl>::value, 107 "AttributeImpl should be trivially destructible"); 108 109 //===----------------------------------------------------------------------===// 110 /// \class 111 /// A set of classes that contain the value of the 112 /// attribute object. There are three main categories: enum attribute entries, 113 /// represented by Attribute::AttrKind; alignment attribute entries; and string 114 /// attribute enties, which are for target-dependent attributes. 115 116 class EnumAttributeImpl : public AttributeImpl { 117 Attribute::AttrKind Kind; 118 119 protected: 120 EnumAttributeImpl(AttrEntryKind ID, Attribute::AttrKind Kind) 121 : AttributeImpl(ID), Kind(Kind) {} 122 123 public: 124 EnumAttributeImpl(Attribute::AttrKind Kind) 125 : AttributeImpl(EnumAttrEntry), Kind(Kind) { 126 assert(Kind != Attribute::AttrKind::None && 127 "Can't create a None attribute!"); 128 } 129 130 Attribute::AttrKind getEnumKind() const { return Kind; } 131 }; 132 133 class IntAttributeImpl : public EnumAttributeImpl { 134 uint64_t Val; 135 136 public: 137 IntAttributeImpl(Attribute::AttrKind Kind, uint64_t Val) 138 : EnumAttributeImpl(IntAttrEntry, Kind), Val(Val) { 139 assert(Attribute::isIntAttrKind(Kind) && 140 "Wrong kind for int attribute!"); 141 } 142 143 uint64_t getValue() const { return Val; } 144 }; 145 146 class StringAttributeImpl final 147 : public AttributeImpl, 148 private TrailingObjects<StringAttributeImpl, char> { 149 friend TrailingObjects; 150 151 unsigned KindSize; 152 unsigned ValSize; 153 size_t numTrailingObjects(OverloadToken<char>) const { 154 return KindSize + 1 + ValSize + 1; 155 } 156 157 public: 158 StringAttributeImpl(StringRef Kind, StringRef Val = StringRef()) 159 : AttributeImpl(StringAttrEntry), KindSize(Kind.size()), 160 ValSize(Val.size()) { 161 char *TrailingString = getTrailingObjects<char>(); 162 // Some users rely on zero-termination. 163 llvm::copy(Kind, TrailingString); 164 TrailingString[KindSize] = '\0'; 165 llvm::copy(Val, &TrailingString[KindSize + 1]); 166 TrailingString[KindSize + 1 + ValSize] = '\0'; 167 } 168 169 StringRef getStringKind() const { 170 return StringRef(getTrailingObjects<char>(), KindSize); 171 } 172 StringRef getStringValue() const { 173 return StringRef(getTrailingObjects<char>() + KindSize + 1, ValSize); 174 } 175 176 static size_t totalSizeToAlloc(StringRef Kind, StringRef Val) { 177 return TrailingObjects::totalSizeToAlloc<char>(Kind.size() + 1 + 178 Val.size() + 1); 179 } 180 }; 181 182 class TypeAttributeImpl : public EnumAttributeImpl { 183 Type *Ty; 184 185 public: 186 TypeAttributeImpl(Attribute::AttrKind Kind, Type *Ty) 187 : EnumAttributeImpl(TypeAttrEntry, Kind), Ty(Ty) {} 188 189 Type *getTypeValue() const { return Ty; } 190 }; 191 192 class AttributeBitSet { 193 /// Bitset with a bit for each available attribute Attribute::AttrKind. 194 uint8_t AvailableAttrs[12] = {}; 195 static_assert(Attribute::EndAttrKinds <= sizeof(AvailableAttrs) * CHAR_BIT, 196 "Too many attributes"); 197 198 public: 199 bool hasAttribute(Attribute::AttrKind Kind) const { 200 return AvailableAttrs[Kind / 8] & (1 << (Kind % 8)); 201 } 202 203 void addAttribute(Attribute::AttrKind Kind) { 204 AvailableAttrs[Kind / 8] |= 1 << (Kind % 8); 205 } 206 }; 207 208 //===----------------------------------------------------------------------===// 209 /// \class 210 /// This class represents a group of attributes that apply to one 211 /// element: function, return type, or parameter. 212 class AttributeSetNode final 213 : public FoldingSetNode, 214 private TrailingObjects<AttributeSetNode, Attribute> { 215 friend TrailingObjects; 216 217 unsigned NumAttrs; ///< Number of attributes in this node. 218 AttributeBitSet AvailableAttrs; ///< Available enum attributes. 219 220 DenseMap<StringRef, Attribute> StringAttrs; 221 222 AttributeSetNode(ArrayRef<Attribute> Attrs); 223 224 static AttributeSetNode *getSorted(LLVMContext &C, 225 ArrayRef<Attribute> SortedAttrs); 226 Optional<Attribute> findEnumAttribute(Attribute::AttrKind Kind) const; 227 228 public: 229 // AttributesSetNode is uniqued, these should not be available. 230 AttributeSetNode(const AttributeSetNode &) = delete; 231 AttributeSetNode &operator=(const AttributeSetNode &) = delete; 232 233 void operator delete(void *p) { ::operator delete(p); } 234 235 static AttributeSetNode *get(LLVMContext &C, const AttrBuilder &B); 236 237 static AttributeSetNode *get(LLVMContext &C, ArrayRef<Attribute> Attrs); 238 239 /// Return the number of attributes this AttributeList contains. 240 unsigned getNumAttributes() const { return NumAttrs; } 241 242 bool hasAttribute(Attribute::AttrKind Kind) const { 243 return AvailableAttrs.hasAttribute(Kind); 244 } 245 bool hasAttribute(StringRef Kind) const; 246 bool hasAttributes() const { return NumAttrs != 0; } 247 248 Attribute getAttribute(Attribute::AttrKind Kind) const; 249 Attribute getAttribute(StringRef Kind) const; 250 251 MaybeAlign getAlignment() const; 252 MaybeAlign getStackAlignment() const; 253 uint64_t getDereferenceableBytes() const; 254 uint64_t getDereferenceableOrNullBytes() const; 255 std::pair<unsigned, Optional<unsigned>> getAllocSizeArgs() const; 256 std::pair<unsigned, unsigned> getVScaleRangeArgs() const; 257 std::string getAsString(bool InAttrGrp) const; 258 Type *getAttributeType(Attribute::AttrKind Kind) const; 259 260 using iterator = const Attribute *; 261 262 iterator begin() const { return getTrailingObjects<Attribute>(); } 263 iterator end() const { return begin() + NumAttrs; } 264 265 void Profile(FoldingSetNodeID &ID) const { 266 Profile(ID, makeArrayRef(begin(), end())); 267 } 268 269 static void Profile(FoldingSetNodeID &ID, ArrayRef<Attribute> AttrList) { 270 for (const auto &Attr : AttrList) 271 Attr.Profile(ID); 272 } 273 }; 274 275 //===----------------------------------------------------------------------===// 276 /// \class 277 /// This class represents a set of attributes that apply to the function, 278 /// return type, and parameters. 279 class AttributeListImpl final 280 : public FoldingSetNode, 281 private TrailingObjects<AttributeListImpl, AttributeSet> { 282 friend class AttributeList; 283 friend TrailingObjects; 284 285 private: 286 unsigned NumAttrSets; ///< Number of entries in this set. 287 /// Available enum function attributes. 288 AttributeBitSet AvailableFunctionAttrs; 289 /// Union of enum attributes available at any index. 290 AttributeBitSet AvailableSomewhereAttrs; 291 292 // Helper fn for TrailingObjects class. 293 size_t numTrailingObjects(OverloadToken<AttributeSet>) { return NumAttrSets; } 294 295 public: 296 AttributeListImpl(ArrayRef<AttributeSet> Sets); 297 298 // AttributesSetImpt is uniqued, these should not be available. 299 AttributeListImpl(const AttributeListImpl &) = delete; 300 AttributeListImpl &operator=(const AttributeListImpl &) = delete; 301 302 /// Return true if the AttributeSet or the FunctionIndex has an 303 /// enum attribute of the given kind. 304 bool hasFnAttribute(Attribute::AttrKind Kind) const { 305 return AvailableFunctionAttrs.hasAttribute(Kind); 306 } 307 308 /// Return true if the specified attribute is set for at least one 309 /// parameter or for the return value. If Index is not nullptr, the index 310 /// of a parameter with the specified attribute is provided. 311 bool hasAttrSomewhere(Attribute::AttrKind Kind, 312 unsigned *Index = nullptr) const; 313 314 using iterator = const AttributeSet *; 315 316 iterator begin() const { return getTrailingObjects<AttributeSet>(); } 317 iterator end() const { return begin() + NumAttrSets; } 318 319 void Profile(FoldingSetNodeID &ID) const; 320 static void Profile(FoldingSetNodeID &ID, ArrayRef<AttributeSet> Nodes); 321 322 void dump() const; 323 }; 324 325 static_assert(std::is_trivially_destructible<AttributeListImpl>::value, 326 "AttributeListImpl should be trivially destructible"); 327 328 } // end namespace llvm 329 330 #endif // LLVM_LIB_IR_ATTRIBUTEIMPL_H 331