llvm/lib/IR/AttributeImpl.h

   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 <optional>
  28 #include <string>
  29 #include <utility>
  30
  31 namespace llvm {
  32
  33 class LLVMContext;
  34 class Type;
  35
  36 //===----------------------------------------------------------------------===//
  37 /// \class
  38 /// This class represents a single, uniqued attribute. That attribute
  39 /// could be a single enum, a tuple, or a string.
  40 class AttributeImpl : public FoldingSetNode {
  41   unsigned char KindID; ///< Holds the AttrEntryKind of the attribute
  42
  43 protected:
  44   enum AttrEntryKind {
  45     EnumAttrEntry,
  46     IntAttrEntry,
  47     StringAttrEntry,
  48     TypeAttrEntry,
  49   };
  50
  51   AttributeImpl(AttrEntryKind KindID) : KindID(KindID) {}
  52
  53 public:
  54   // AttributesImpl is uniqued, these should not be available.
  55   AttributeImpl(const AttributeImpl &) = delete;
  56   AttributeImpl &operator=(const AttributeImpl &) = delete;
  57
  58   bool isEnumAttribute() const { return KindID == EnumAttrEntry; }
  59   bool isIntAttribute() const { return KindID == IntAttrEntry; }
  60   bool isStringAttribute() const { return KindID == StringAttrEntry; }
  61   bool isTypeAttribute() const { return KindID == TypeAttrEntry; }
  62
  63   bool hasAttribute(Attribute::AttrKind A) const;
  64   bool hasAttribute(StringRef Kind) const;
  65
  66   Attribute::AttrKind getKindAsEnum() const;
  67   uint64_t getValueAsInt() const;
  68   bool getValueAsBool() const;
  69
  70   StringRef getKindAsString() const;
  71   StringRef getValueAsString() const;
  72
  73   Type *getValueAsType() const;
  74
  75   /// Used when sorting the attributes.
  76   bool operator<(const AttributeImpl &AI) const;
  77
  78   void Profile(FoldingSetNodeID &ID) const {
  79     if (isEnumAttribute())
  80       Profile(ID, getKindAsEnum());
  81     else if (isIntAttribute())
  82       Profile(ID, getKindAsEnum(), getValueAsInt());
  83     else if (isStringAttribute())
  84       Profile(ID, getKindAsString(), getValueAsString());
  85     else
  86       Profile(ID, getKindAsEnum(), getValueAsType());
  87   }
  88
  89   static void Profile(FoldingSetNodeID &ID, Attribute::AttrKind Kind) {
  90     assert(Attribute::isEnumAttrKind(Kind) && "Expected enum attribute");
  91     ID.AddInteger(Kind);
  92   }
  93
  94   static void Profile(FoldingSetNodeID &ID, Attribute::AttrKind Kind,
  95                       uint64_t Val) {
  96     assert(Attribute::isIntAttrKind(Kind) && "Expected int attribute");
  97     ID.AddInteger(Kind);
  98     ID.AddInteger(Val);
  99   }
 100
 101   static void Profile(FoldingSetNodeID &ID, StringRef Kind, StringRef Values) {
 102     ID.AddString(Kind);
 103     if (!Values.empty()) ID.AddString(Values);
 104   }
 105
 106   static void Profile(FoldingSetNodeID &ID, Attribute::AttrKind Kind,
 107                       Type *Ty) {
 108     ID.AddInteger(Kind);
 109     ID.AddPointer(Ty);
 110   }
 111 };
 112
 113 static_assert(std::is_trivially_destructible<AttributeImpl>::value,
 114               "AttributeImpl should be trivially destructible");
 115
 116 //===----------------------------------------------------------------------===//
 117 /// \class
 118 /// A set of classes that contain the value of the
 119 /// attribute object. There are three main categories: enum attribute entries,
 120 /// represented by Attribute::AttrKind; alignment attribute entries; and string
 121 /// attribute enties, which are for target-dependent attributes.
 122
 123 class EnumAttributeImpl : public AttributeImpl {
 124   Attribute::AttrKind Kind;
 125
 126 protected:
 127   EnumAttributeImpl(AttrEntryKind ID, Attribute::AttrKind Kind)
 128       : AttributeImpl(ID), Kind(Kind) {}
 129
 130 public:
 131   EnumAttributeImpl(Attribute::AttrKind Kind)
 132       : AttributeImpl(EnumAttrEntry), Kind(Kind) {
 133     assert(Kind != Attribute::AttrKind::None &&
 134            "Can't create a None attribute!");
 135   }
 136
 137   Attribute::AttrKind getEnumKind() const { return Kind; }
 138 };
 139
 140 class IntAttributeImpl : public EnumAttributeImpl {
 141   uint64_t Val;
 142
 143 public:
 144   IntAttributeImpl(Attribute::AttrKind Kind, uint64_t Val)
 145       : EnumAttributeImpl(IntAttrEntry, Kind), Val(Val) {
 146     assert(Attribute::isIntAttrKind(Kind) &&
 147            "Wrong kind for int attribute!");
 148   }
 149
 150   uint64_t getValue() const { return Val; }
 151 };
 152
 153 class StringAttributeImpl final
 154     : public AttributeImpl,
 155       private TrailingObjects<StringAttributeImpl, char> {
 156   friend TrailingObjects;
 157
 158   unsigned KindSize;
 159   unsigned ValSize;
 160   size_t numTrailingObjects(OverloadToken<char>) const {
 161     return KindSize + 1 + ValSize + 1;
 162   }
 163
 164 public:
 165   StringAttributeImpl(StringRef Kind, StringRef Val = StringRef())
 166       : AttributeImpl(StringAttrEntry), KindSize(Kind.size()),
 167         ValSize(Val.size()) {
 168     char *TrailingString = getTrailingObjects<char>();
 169     // Some users rely on zero-termination.
 170     llvm::copy(Kind, TrailingString);
 171     TrailingString[KindSize] = '\0';
 172     llvm::copy(Val, &TrailingString[KindSize + 1]);
 173     TrailingString[KindSize + 1 + ValSize] = '\0';
 174   }
 175
 176   StringRef getStringKind() const {
 177     return StringRef(getTrailingObjects<char>(), KindSize);
 178   }
 179   StringRef getStringValue() const {
 180     return StringRef(getTrailingObjects<char>() + KindSize + 1, ValSize);
 181   }
 182
 183   static size_t totalSizeToAlloc(StringRef Kind, StringRef Val) {
 184     return TrailingObjects::totalSizeToAlloc<char>(Kind.size() + 1 +
 185                                                    Val.size() + 1);
 186   }
 187 };
 188
 189 class TypeAttributeImpl : public EnumAttributeImpl {
 190   Type *Ty;
 191
 192 public:
 193   TypeAttributeImpl(Attribute::AttrKind Kind, Type *Ty)
 194       : EnumAttributeImpl(TypeAttrEntry, Kind), Ty(Ty) {}
 195
 196   Type *getTypeValue() const { return Ty; }
 197 };
 198
 199 class AttributeBitSet {
 200   /// Bitset with a bit for each available attribute Attribute::AttrKind.
 201   uint8_t AvailableAttrs[12] = {};
 202   static_assert(Attribute::EndAttrKinds <= sizeof(AvailableAttrs) * CHAR_BIT,
 203                 "Too many attributes");
 204
 205 public:
 206   bool hasAttribute(Attribute::AttrKind Kind) const {
 207     return AvailableAttrs[Kind / 8] & (1 << (Kind % 8));
 208   }
 209
 210   void addAttribute(Attribute::AttrKind Kind) {
 211     AvailableAttrs[Kind / 8] |= 1 << (Kind % 8);
 212   }
 213 };
 214
 215 //===----------------------------------------------------------------------===//
 216 /// \class
 217 /// This class represents a group of attributes that apply to one
 218 /// element: function, return type, or parameter.
 219 class AttributeSetNode final
 220     : public FoldingSetNode,
 221       private TrailingObjects<AttributeSetNode, Attribute> {
 222   friend TrailingObjects;
 223
 224   unsigned NumAttrs; ///< Number of attributes in this node.
 225   AttributeBitSet AvailableAttrs; ///< Available enum attributes.
 226
 227   DenseMap<StringRef, Attribute> StringAttrs;
 228
 229   AttributeSetNode(ArrayRef<Attribute> Attrs);
 230
 231   static AttributeSetNode *getSorted(LLVMContext &C,
 232                                      ArrayRef<Attribute> SortedAttrs);
 233   std::optional<Attribute> findEnumAttribute(Attribute::AttrKind Kind) const;
 234
 235 public:
 236   // AttributesSetNode is uniqued, these should not be available.
 237   AttributeSetNode(const AttributeSetNode &) = delete;
 238   AttributeSetNode &operator=(const AttributeSetNode &) = delete;
 239
 240   void operator delete(void *p) { ::operator delete(p); }
 241
 242   static AttributeSetNode *get(LLVMContext &C, const AttrBuilder &B);
 243
 244   static AttributeSetNode *get(LLVMContext &C, ArrayRef<Attribute> Attrs);
 245
 246   /// Return the number of attributes this AttributeList contains.
 247   unsigned getNumAttributes() const { return NumAttrs; }
 248
 249   bool hasAttribute(Attribute::AttrKind Kind) const {
 250     return AvailableAttrs.hasAttribute(Kind);
 251   }
 252   bool hasAttribute(StringRef Kind) const;
 253   bool hasAttributes() const { return NumAttrs != 0; }
 254
 255   Attribute getAttribute(Attribute::AttrKind Kind) const;
 256   Attribute getAttribute(StringRef Kind) const;
 257
 258   MaybeAlign getAlignment() const;
 259   MaybeAlign getStackAlignment() const;
 260   uint64_t getDereferenceableBytes() const;
 261   uint64_t getDereferenceableOrNullBytes() const;
 262   std::optional<std::pair<unsigned, std::optional<unsigned>>> getAllocSizeArgs()
 263       const;
 264   unsigned getVScaleRangeMin() const;
 265   std::optional<unsigned> getVScaleRangeMax() const;
 266   UWTableKind getUWTableKind() const;
 267   AllocFnKind getAllocKind() const;
 268   MemoryEffects getMemoryEffects() const;
 269   FPClassTest getNoFPClass() const;
 270   std::string getAsString(bool InAttrGrp) const;
 271   Type *getAttributeType(Attribute::AttrKind Kind) const;
 272
 273   using iterator = const Attribute *;
 274
 275   iterator begin() const { return getTrailingObjects<Attribute>(); }
 276   iterator end() const { return begin() + NumAttrs; }
 277
 278   void Profile(FoldingSetNodeID &ID) const {
 279     Profile(ID, ArrayRef(begin(), end()));
 280   }
 281
 282   static void Profile(FoldingSetNodeID &ID, ArrayRef<Attribute> AttrList) {
 283     for (const auto &Attr : AttrList)
 284       Attr.Profile(ID);
 285   }
 286 };
 287
 288 //===----------------------------------------------------------------------===//
 289 /// \class
 290 /// This class represents a set of attributes that apply to the function,
 291 /// return type, and parameters.
 292 class AttributeListImpl final
 293     : public FoldingSetNode,
 294       private TrailingObjects<AttributeListImpl, AttributeSet> {
 295   friend class AttributeList;
 296   friend TrailingObjects;
 297
 298 private:
 299   unsigned NumAttrSets; ///< Number of entries in this set.
 300   /// Available enum function attributes.
 301   AttributeBitSet AvailableFunctionAttrs;
 302   /// Union of enum attributes available at any index.
 303   AttributeBitSet AvailableSomewhereAttrs;
 304
 305   // Helper fn for TrailingObjects class.
 306   size_t numTrailingObjects(OverloadToken<AttributeSet>) { return NumAttrSets; }
 307
 308 public:
 309   AttributeListImpl(ArrayRef<AttributeSet> Sets);
 310
 311   // AttributesSetImpt is uniqued, these should not be available.
 312   AttributeListImpl(const AttributeListImpl &) = delete;
 313   AttributeListImpl &operator=(const AttributeListImpl &) = delete;
 314
 315   /// Return true if the AttributeSet or the FunctionIndex has an
 316   /// enum attribute of the given kind.
 317   bool hasFnAttribute(Attribute::AttrKind Kind) const {
 318     return AvailableFunctionAttrs.hasAttribute(Kind);
 319   }
 320
 321   /// Return true if the specified attribute is set for at least one
 322   /// parameter or for the return value. If Index is not nullptr, the index
 323   /// of a parameter with the specified attribute is provided.
 324   bool hasAttrSomewhere(Attribute::AttrKind Kind,
 325                         unsigned *Index = nullptr) const;
 326
 327   using iterator = const AttributeSet *;
 328
 329   iterator begin() const { return getTrailingObjects<AttributeSet>(); }
 330   iterator end() const { return begin() + NumAttrSets; }
 331
 332   void Profile(FoldingSetNodeID &ID) const;
 333   static void Profile(FoldingSetNodeID &ID, ArrayRef<AttributeSet> Nodes);
 334
 335   void dump() const;
 336 };
 337
 338 static_assert(std::is_trivially_destructible<AttributeListImpl>::value,
 339               "AttributeListImpl should be trivially destructible");
 340
 341 } // end namespace llvm
 342
 343 #endif // LLVM_LIB_IR_ATTRIBUTEIMPL_H