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 <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