include/llvm/IR/Attributes.h

   1 //===- llvm/Attributes.h - Container for Attributes -------------*- 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 contains the simple types necessary to represent the
  11 /// attributes associated with functions and their calls.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef LLVM_IR_ATTRIBUTES_H
  16 #define LLVM_IR_ATTRIBUTES_H
  17
  18 #include "llvm-c/Types.h"
  19 #include "llvm/ADT/ArrayRef.h"
  20 #include "llvm/ADT/FoldingSet.h"
  21 #include "llvm/ADT/Optional.h"
  22 #include "llvm/ADT/StringRef.h"
  23 #include "llvm/ADT/iterator_range.h"
  24 #include "llvm/Config/llvm-config.h"
  25 #include "llvm/Support/PointerLikeTypeTraits.h"
  26 #include <bitset>
  27 #include <cassert>
  28 #include <cstdint>
  29 #include <map>
  30 #include <string>
  31 #include <utility>
  32
  33 namespace llvm {
  34
  35 class AttrBuilder;
  36 class AttributeImpl;
  37 class AttributeListImpl;
  38 class AttributeSetNode;
  39 template<typename T> struct DenseMapInfo;
  40 class Function;
  41 class LLVMContext;
  42 class Type;
  43
  44 //===----------------------------------------------------------------------===//
  45 /// \class
  46 /// Functions, function parameters, and return types can have attributes
  47 /// to indicate how they should be treated by optimizations and code
  48 /// generation. This class represents one of those attributes. It's light-weight
  49 /// and should be passed around by-value.
  50 class Attribute {
  51 public:
  52   /// This enumeration lists the attributes that can be associated with
  53   /// parameters, function results, or the function itself.
  54   ///
  55   /// Note: The `uwtable' attribute is about the ABI or the user mandating an
  56   /// entry in the unwind table. The `nounwind' attribute is about an exception
  57   /// passing by the function.
  58   ///
  59   /// In a theoretical system that uses tables for profiling and SjLj for
  60   /// exceptions, they would be fully independent. In a normal system that uses
  61   /// tables for both, the semantics are:
  62   ///
  63   /// nil                = Needs an entry because an exception might pass by.
  64   /// nounwind           = No need for an entry
  65   /// uwtable            = Needs an entry because the ABI says so and because
  66   ///                      an exception might pass by.
  67   /// uwtable + nounwind = Needs an entry because the ABI says so.
  68
  69   enum AttrKind {
  70     // IR-Level Attributes
  71     None,                  ///< No attributes have been set
  72     #define GET_ATTR_ENUM
  73     #include "llvm/IR/Attributes.inc"
  74     EndAttrKinds           ///< Sentinal value useful for loops
  75   };
  76
  77 private:
  78   AttributeImpl *pImpl = nullptr;
  79
  80   Attribute(AttributeImpl *A) : pImpl(A) {}
  81
  82 public:
  83   Attribute() = default;
  84
  85   //===--------------------------------------------------------------------===//
  86   // Attribute Construction
  87   //===--------------------------------------------------------------------===//
  88
  89   /// Return a uniquified Attribute object.
  90   static Attribute get(LLVMContext &Context, AttrKind Kind, uint64_t Val = 0);
  91   static Attribute get(LLVMContext &Context, StringRef Kind,
  92                        StringRef Val = StringRef());
  93   static Attribute get(LLVMContext &Context, AttrKind Kind, Type *Ty);
  94
  95   /// Return a uniquified Attribute object that has the specific
  96   /// alignment set.
  97   static Attribute getWithAlignment(LLVMContext &Context, uint64_t Align);
  98   static Attribute getWithStackAlignment(LLVMContext &Context, uint64_t Align);
  99   static Attribute getWithDereferenceableBytes(LLVMContext &Context,
 100                                               uint64_t Bytes);
 101   static Attribute getWithDereferenceableOrNullBytes(LLVMContext &Context,
 102                                                      uint64_t Bytes);
 103   static Attribute getWithAllocSizeArgs(LLVMContext &Context,
 104                                         unsigned ElemSizeArg,
 105                                         const Optional<unsigned> &NumElemsArg);
 106   static Attribute getWithByValType(LLVMContext &Context, Type *Ty);
 107
 108   //===--------------------------------------------------------------------===//
 109   // Attribute Accessors
 110   //===--------------------------------------------------------------------===//
 111
 112   /// Return true if the attribute is an Attribute::AttrKind type.
 113   bool isEnumAttribute() const;
 114
 115   /// Return true if the attribute is an integer attribute.
 116   bool isIntAttribute() const;
 117
 118   /// Return true if the attribute is a string (target-dependent)
 119   /// attribute.
 120   bool isStringAttribute() const;
 121
 122   /// Return true if the attribute is a type attribute.
 123   bool isTypeAttribute() const;
 124
 125   /// Return true if the attribute is present.
 126   bool hasAttribute(AttrKind Val) const;
 127
 128   /// Return true if the target-dependent attribute is present.
 129   bool hasAttribute(StringRef Val) const;
 130
 131   /// Return the attribute's kind as an enum (Attribute::AttrKind). This
 132   /// requires the attribute to be an enum or integer attribute.
 133   Attribute::AttrKind getKindAsEnum() const;
 134
 135   /// Return the attribute's value as an integer. This requires that the
 136   /// attribute be an integer attribute.
 137   uint64_t getValueAsInt() const;
 138
 139   /// Return the attribute's kind as a string. This requires the
 140   /// attribute to be a string attribute.
 141   StringRef getKindAsString() const;
 142
 143   /// Return the attribute's value as a string. This requires the
 144   /// attribute to be a string attribute.
 145   StringRef getValueAsString() const;
 146
 147   /// Return the attribute's value as a Type. This requires the attribute to be
 148   /// a type attribute.
 149   Type *getValueAsType() const;
 150
 151   /// Returns the alignment field of an attribute as a byte alignment
 152   /// value.
 153   unsigned getAlignment() const;
 154
 155   /// Returns the stack alignment field of an attribute as a byte
 156   /// alignment value.
 157   unsigned getStackAlignment() const;
 158
 159   /// Returns the number of dereferenceable bytes from the
 160   /// dereferenceable attribute.
 161   uint64_t getDereferenceableBytes() const;
 162
 163   /// Returns the number of dereferenceable_or_null bytes from the
 164   /// dereferenceable_or_null attribute.
 165   uint64_t getDereferenceableOrNullBytes() const;
 166
 167   /// Returns the argument numbers for the allocsize attribute (or pair(0, 0)
 168   /// if not known).
 169   std::pair<unsigned, Optional<unsigned>> getAllocSizeArgs() const;
 170
 171   /// The Attribute is converted to a string of equivalent mnemonic. This
 172   /// is, presumably, for writing out the mnemonics for the assembly writer.
 173   std::string getAsString(bool InAttrGrp = false) const;
 174
 175   /// Equality and non-equality operators.
 176   bool operator==(Attribute A) const { return pImpl == A.pImpl; }
 177   bool operator!=(Attribute A) const { return pImpl != A.pImpl; }
 178
 179   /// Less-than operator. Useful for sorting the attributes list.
 180   bool operator<(Attribute A) const;
 181
 182   void Profile(FoldingSetNodeID &ID) const {
 183     ID.AddPointer(pImpl);
 184   }
 185
 186   /// Return a raw pointer that uniquely identifies this attribute.
 187   void *getRawPointer() const {
 188     return pImpl;
 189   }
 190
 191   /// Get an attribute from a raw pointer created by getRawPointer.
 192   static Attribute fromRawPointer(void *RawPtr) {
 193     return Attribute(reinterpret_cast<AttributeImpl*>(RawPtr));
 194   }
 195 };
 196
 197 // Specialized opaque value conversions.
 198 inline LLVMAttributeRef wrap(Attribute Attr) {
 199   return reinterpret_cast<LLVMAttributeRef>(Attr.getRawPointer());
 200 }
 201
 202 // Specialized opaque value conversions.
 203 inline Attribute unwrap(LLVMAttributeRef Attr) {
 204   return Attribute::fromRawPointer(Attr);
 205 }
 206
 207 //===----------------------------------------------------------------------===//
 208 /// \class
 209 /// This class holds the attributes for a particular argument, parameter,
 210 /// function, or return value. It is an immutable value type that is cheap to
 211 /// copy. Adding and removing enum attributes is intended to be fast, but adding
 212 /// and removing string or integer attributes involves a FoldingSet lookup.
 213 class AttributeSet {
 214   friend AttributeListImpl;
 215   template <typename Ty> friend struct DenseMapInfo;
 216
 217   // TODO: Extract AvailableAttrs from AttributeSetNode and store them here.
 218   // This will allow an efficient implementation of addAttribute and
 219   // removeAttribute for enum attrs.
 220
 221   /// Private implementation pointer.
 222   AttributeSetNode *SetNode = nullptr;
 223
 224 private:
 225   explicit AttributeSet(AttributeSetNode *ASN) : SetNode(ASN) {}
 226
 227 public:
 228   /// AttributeSet is a trivially copyable value type.
 229   AttributeSet() = default;
 230   AttributeSet(const AttributeSet &) = default;
 231   ~AttributeSet() = default;
 232
 233   static AttributeSet get(LLVMContext &C, const AttrBuilder &B);
 234   static AttributeSet get(LLVMContext &C, ArrayRef<Attribute> Attrs);
 235
 236   bool operator==(const AttributeSet &O) const { return SetNode == O.SetNode; }
 237   bool operator!=(const AttributeSet &O) const { return !(*this == O); }
 238
 239   /// Add an argument attribute. Returns a new set because attribute sets are
 240   /// immutable.
 241   LLVM_NODISCARD AttributeSet addAttribute(LLVMContext &C,
 242                                            Attribute::AttrKind Kind) const;
 243
 244   /// Add a target-dependent attribute. Returns a new set because attribute sets
 245   /// are immutable.
 246   LLVM_NODISCARD AttributeSet addAttribute(LLVMContext &C, StringRef Kind,
 247                                            StringRef Value = StringRef()) const;
 248
 249   /// Add attributes to the attribute set. Returns a new set because attribute
 250   /// sets are immutable.
 251   LLVM_NODISCARD AttributeSet addAttributes(LLVMContext &C,
 252                                             AttributeSet AS) const;
 253
 254   /// Remove the specified attribute from this set. Returns a new set because
 255   /// attribute sets are immutable.
 256   LLVM_NODISCARD AttributeSet removeAttribute(LLVMContext &C,
 257                                               Attribute::AttrKind Kind) const;
 258
 259   /// Remove the specified attribute from this set. Returns a new set because
 260   /// attribute sets are immutable.
 261   LLVM_NODISCARD AttributeSet removeAttribute(LLVMContext &C,
 262                                               StringRef Kind) const;
 263
 264   /// Remove the specified attributes from this set. Returns a new set because
 265   /// attribute sets are immutable.
 266   LLVM_NODISCARD AttributeSet
 267   removeAttributes(LLVMContext &C, const AttrBuilder &AttrsToRemove) const;
 268
 269   /// Return the number of attributes in this set.
 270   unsigned getNumAttributes() const;
 271
 272   /// Return true if attributes exists in this set.
 273   bool hasAttributes() const { return SetNode != nullptr; }
 274
 275   /// Return true if the attribute exists in this set.
 276   bool hasAttribute(Attribute::AttrKind Kind) const;
 277
 278   /// Return true if the attribute exists in this set.
 279   bool hasAttribute(StringRef Kind) const;
 280
 281   /// Return the attribute object.
 282   Attribute getAttribute(Attribute::AttrKind Kind) const;
 283
 284   /// Return the target-dependent attribute object.
 285   Attribute getAttribute(StringRef Kind) const;
 286
 287   unsigned getAlignment() const;
 288   unsigned getStackAlignment() const;
 289   uint64_t getDereferenceableBytes() const;
 290   uint64_t getDereferenceableOrNullBytes() const;
 291   Type *getByValType() const;
 292   std::pair<unsigned, Optional<unsigned>> getAllocSizeArgs() const;
 293   std::string getAsString(bool InAttrGrp = false) const;
 294
 295   using iterator = const Attribute *;
 296
 297   iterator begin() const;
 298   iterator end() const;
 299 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 300   void dump() const;
 301 #endif
 302 };
 303
 304 //===----------------------------------------------------------------------===//
 305 /// \class
 306 /// Provide DenseMapInfo for AttributeSet.
 307 template <> struct DenseMapInfo<AttributeSet> {
 308   static AttributeSet getEmptyKey() {
 309     auto Val = static_cast<uintptr_t>(-1);
 310     Val <<= PointerLikeTypeTraits<void *>::NumLowBitsAvailable;
 311     return AttributeSet(reinterpret_cast<AttributeSetNode *>(Val));
 312   }
 313
 314   static AttributeSet getTombstoneKey() {
 315     auto Val = static_cast<uintptr_t>(-2);
 316     Val <<= PointerLikeTypeTraits<void *>::NumLowBitsAvailable;
 317     return AttributeSet(reinterpret_cast<AttributeSetNode *>(Val));
 318   }
 319
 320   static unsigned getHashValue(AttributeSet AS) {
 321     return (unsigned((uintptr_t)AS.SetNode) >> 4) ^
 322            (unsigned((uintptr_t)AS.SetNode) >> 9);
 323   }
 324
 325   static bool isEqual(AttributeSet LHS, AttributeSet RHS) { return LHS == RHS; }
 326 };
 327
 328 //===----------------------------------------------------------------------===//
 329 /// \class
 330 /// This class holds the attributes for a function, its return value, and
 331 /// its parameters. You access the attributes for each of them via an index into
 332 /// the AttributeList object. The function attributes are at index
 333 /// `AttributeList::FunctionIndex', the return value is at index
 334 /// `AttributeList::ReturnIndex', and the attributes for the parameters start at
 335 /// index `AttributeList::FirstArgIndex'.
 336 class AttributeList {
 337 public:
 338   enum AttrIndex : unsigned {
 339     ReturnIndex = 0U,
 340     FunctionIndex = ~0U,
 341     FirstArgIndex = 1,
 342   };
 343
 344 private:
 345   friend class AttrBuilder;
 346   friend class AttributeListImpl;
 347   friend class AttributeSet;
 348   friend class AttributeSetNode;
 349   template <typename Ty> friend struct DenseMapInfo;
 350
 351   /// The attributes that we are managing. This can be null to represent
 352   /// the empty attributes list.
 353   AttributeListImpl *pImpl = nullptr;
 354
 355 public:
 356   /// Create an AttributeList with the specified parameters in it.
 357   static AttributeList get(LLVMContext &C,
 358                            ArrayRef<std::pair<unsigned, Attribute>> Attrs);
 359   static AttributeList get(LLVMContext &C,
 360                            ArrayRef<std::pair<unsigned, AttributeSet>> Attrs);
 361
 362   /// Create an AttributeList from attribute sets for a function, its
 363   /// return value, and all of its arguments.
 364   static AttributeList get(LLVMContext &C, AttributeSet FnAttrs,
 365                            AttributeSet RetAttrs,
 366                            ArrayRef<AttributeSet> ArgAttrs);
 367
 368 private:
 369   explicit AttributeList(AttributeListImpl *LI) : pImpl(LI) {}
 370
 371   static AttributeList getImpl(LLVMContext &C, ArrayRef<AttributeSet> AttrSets);
 372
 373 public:
 374   AttributeList() = default;
 375
 376   //===--------------------------------------------------------------------===//
 377   // AttributeList Construction and Mutation
 378   //===--------------------------------------------------------------------===//
 379
 380   /// Return an AttributeList with the specified parameters in it.
 381   static AttributeList get(LLVMContext &C, ArrayRef<AttributeList> Attrs);
 382   static AttributeList get(LLVMContext &C, unsigned Index,
 383                            ArrayRef<Attribute::AttrKind> Kinds);
 384   static AttributeList get(LLVMContext &C, unsigned Index,
 385                            ArrayRef<StringRef> Kind);
 386   static AttributeList get(LLVMContext &C, unsigned Index,
 387                            const AttrBuilder &B);
 388
 389   /// Add an attribute to the attribute set at the given index.
 390   /// Returns a new list because attribute lists are immutable.
 391   LLVM_NODISCARD AttributeList addAttribute(LLVMContext &C, unsigned Index,
 392                                             Attribute::AttrKind Kind) const;
 393
 394   /// Add an attribute to the attribute set at the given index.
 395   /// Returns a new list because attribute lists are immutable.
 396   LLVM_NODISCARD AttributeList
 397   addAttribute(LLVMContext &C, unsigned Index, StringRef Kind,
 398                StringRef Value = StringRef()) const;
 399
 400   /// Add an attribute to the attribute set at the given index.
 401   /// Returns a new list because attribute lists are immutable.
 402   LLVM_NODISCARD AttributeList addAttribute(LLVMContext &C, unsigned Index,
 403                                             Attribute A) const;
 404
 405   /// Add attributes to the attribute set at the given index.
 406   /// Returns a new list because attribute lists are immutable.
 407   LLVM_NODISCARD AttributeList addAttributes(LLVMContext &C, unsigned Index,
 408                                              const AttrBuilder &B) const;
 409
 410   /// Add an argument attribute to the list. Returns a new list because
 411   /// attribute lists are immutable.
 412   LLVM_NODISCARD AttributeList addParamAttribute(
 413       LLVMContext &C, unsigned ArgNo, Attribute::AttrKind Kind) const {
 414     return addAttribute(C, ArgNo + FirstArgIndex, Kind);
 415   }
 416
 417   /// Add an argument attribute to the list. Returns a new list because
 418   /// attribute lists are immutable.
 419   LLVM_NODISCARD AttributeList
 420   addParamAttribute(LLVMContext &C, unsigned ArgNo, StringRef Kind,
 421                     StringRef Value = StringRef()) const {
 422     return addAttribute(C, ArgNo + FirstArgIndex, Kind, Value);
 423   }
 424
 425   /// Add an attribute to the attribute list at the given arg indices. Returns a
 426   /// new list because attribute lists are immutable.
 427   LLVM_NODISCARD AttributeList addParamAttribute(LLVMContext &C,
 428                                                  ArrayRef<unsigned> ArgNos,
 429                                                  Attribute A) const;
 430
 431   /// Add an argument attribute to the list. Returns a new list because
 432   /// attribute lists are immutable.
 433   LLVM_NODISCARD AttributeList addParamAttributes(LLVMContext &C,
 434                                                   unsigned ArgNo,
 435                                                   const AttrBuilder &B) const {
 436     return addAttributes(C, ArgNo + FirstArgIndex, B);
 437   }
 438
 439   /// Remove the specified attribute at the specified index from this
 440   /// attribute list. Returns a new list because attribute lists are immutable.
 441   LLVM_NODISCARD AttributeList removeAttribute(LLVMContext &C, unsigned Index,
 442                                                Attribute::AttrKind Kind) const;
 443
 444   /// Remove the specified attribute at the specified index from this
 445   /// attribute list. Returns a new list because attribute lists are immutable.
 446   LLVM_NODISCARD AttributeList removeAttribute(LLVMContext &C, unsigned Index,
 447                                                StringRef Kind) const;
 448
 449   /// Remove the specified attributes at the specified index from this
 450   /// attribute list. Returns a new list because attribute lists are immutable.
 451   LLVM_NODISCARD AttributeList removeAttributes(
 452       LLVMContext &C, unsigned Index, const AttrBuilder &AttrsToRemove) const;
 453
 454   /// Remove all attributes at the specified index from this
 455   /// attribute list. Returns a new list because attribute lists are immutable.
 456   LLVM_NODISCARD AttributeList removeAttributes(LLVMContext &C,
 457                                                 unsigned Index) const;
 458
 459   /// Remove the specified attribute at the specified arg index from this
 460   /// attribute list. Returns a new list because attribute lists are immutable.
 461   LLVM_NODISCARD AttributeList removeParamAttribute(
 462       LLVMContext &C, unsigned ArgNo, Attribute::AttrKind Kind) const {
 463     return removeAttribute(C, ArgNo + FirstArgIndex, Kind);
 464   }
 465
 466   /// Remove the specified attribute at the specified arg index from this
 467   /// attribute list. Returns a new list because attribute lists are immutable.
 468   LLVM_NODISCARD AttributeList removeParamAttribute(LLVMContext &C,
 469                                                     unsigned ArgNo,
 470                                                     StringRef Kind) const {
 471     return removeAttribute(C, ArgNo + FirstArgIndex, Kind);
 472   }
 473
 474   /// Remove the specified attribute at the specified arg index from this
 475   /// attribute list. Returns a new list because attribute lists are immutable.
 476   LLVM_NODISCARD AttributeList removeParamAttributes(
 477       LLVMContext &C, unsigned ArgNo, const AttrBuilder &AttrsToRemove) const {
 478     return removeAttributes(C, ArgNo + FirstArgIndex, AttrsToRemove);
 479   }
 480
 481   /// Remove all attributes at the specified arg index from this
 482   /// attribute list. Returns a new list because attribute lists are immutable.
 483   LLVM_NODISCARD AttributeList removeParamAttributes(LLVMContext &C,
 484                                                      unsigned ArgNo) const {
 485     return removeAttributes(C, ArgNo + FirstArgIndex);
 486   }
 487
 488   /// \brief Add the dereferenceable attribute to the attribute set at the given
 489   /// index. Returns a new list because attribute lists are immutable.
 490   LLVM_NODISCARD AttributeList addDereferenceableAttr(LLVMContext &C,
 491                                                       unsigned Index,
 492                                                       uint64_t Bytes) const;
 493
 494   /// \brief Add the dereferenceable attribute to the attribute set at the given
 495   /// arg index. Returns a new list because attribute lists are immutable.
 496   LLVM_NODISCARD AttributeList addDereferenceableParamAttr(
 497       LLVMContext &C, unsigned ArgNo, uint64_t Bytes) const {
 498     return addDereferenceableAttr(C, ArgNo + FirstArgIndex, Bytes);
 499   }
 500
 501   /// Add the dereferenceable_or_null attribute to the attribute set at
 502   /// the given index. Returns a new list because attribute lists are immutable.
 503   LLVM_NODISCARD AttributeList addDereferenceableOrNullAttr(
 504       LLVMContext &C, unsigned Index, uint64_t Bytes) const;
 505
 506   /// Add the dereferenceable_or_null attribute to the attribute set at
 507   /// the given arg index. Returns a new list because attribute lists are
 508   /// immutable.
 509   LLVM_NODISCARD AttributeList addDereferenceableOrNullParamAttr(
 510       LLVMContext &C, unsigned ArgNo, uint64_t Bytes) const {
 511     return addDereferenceableOrNullAttr(C, ArgNo + FirstArgIndex, Bytes);
 512   }
 513
 514   /// Add the allocsize attribute to the attribute set at the given index.
 515   /// Returns a new list because attribute lists are immutable.
 516   LLVM_NODISCARD AttributeList
 517   addAllocSizeAttr(LLVMContext &C, unsigned Index, unsigned ElemSizeArg,
 518                    const Optional<unsigned> &NumElemsArg);
 519
 520   /// Add the allocsize attribute to the attribute set at the given arg index.
 521   /// Returns a new list because attribute lists are immutable.
 522   LLVM_NODISCARD AttributeList
 523   addAllocSizeParamAttr(LLVMContext &C, unsigned ArgNo, unsigned ElemSizeArg,
 524                         const Optional<unsigned> &NumElemsArg) {
 525     return addAllocSizeAttr(C, ArgNo + FirstArgIndex, ElemSizeArg, NumElemsArg);
 526   }
 527
 528   //===--------------------------------------------------------------------===//
 529   // AttributeList Accessors
 530   //===--------------------------------------------------------------------===//
 531
 532   /// Retrieve the LLVM context.
 533   LLVMContext &getContext() const;
 534
 535   /// The attributes for the specified index are returned.
 536   AttributeSet getAttributes(unsigned Index) const;
 537
 538   /// The attributes for the argument or parameter at the given index are
 539   /// returned.
 540   AttributeSet getParamAttributes(unsigned ArgNo) const;
 541
 542   /// The attributes for the ret value are returned.
 543   AttributeSet getRetAttributes() const;
 544
 545   /// The function attributes are returned.
 546   AttributeSet getFnAttributes() const;
 547
 548   /// Return true if the attribute exists at the given index.
 549   bool hasAttribute(unsigned Index, Attribute::AttrKind Kind) const;
 550
 551   /// Return true if the attribute exists at the given index.
 552   bool hasAttribute(unsigned Index, StringRef Kind) const;
 553
 554   /// Return true if attribute exists at the given index.
 555   bool hasAttributes(unsigned Index) const;
 556
 557   /// Return true if the attribute exists for the given argument
 558   bool hasParamAttr(unsigned ArgNo, Attribute::AttrKind Kind) const {
 559     return hasAttribute(ArgNo + FirstArgIndex, Kind);
 560   }
 561
 562   /// Return true if the attribute exists for the given argument
 563   bool hasParamAttr(unsigned ArgNo, StringRef Kind) const {
 564     return hasAttribute(ArgNo + FirstArgIndex, Kind);
 565   }
 566
 567   /// Return true if attributes exists for the given argument
 568   bool hasParamAttrs(unsigned ArgNo) const {
 569     return hasAttributes(ArgNo + FirstArgIndex);
 570   }
 571
 572   /// Equivalent to hasAttribute(AttributeList::FunctionIndex, Kind) but
 573   /// may be faster.
 574   bool hasFnAttribute(Attribute::AttrKind Kind) const;
 575
 576   /// Equivalent to hasAttribute(AttributeList::FunctionIndex, Kind) but
 577   /// may be faster.
 578   bool hasFnAttribute(StringRef Kind) const;
 579
 580   /// Equivalent to hasAttribute(ArgNo + FirstArgIndex, Kind).
 581   bool hasParamAttribute(unsigned ArgNo, Attribute::AttrKind Kind) const;
 582
 583   /// Return true if the specified attribute is set for at least one
 584   /// parameter or for the return value. If Index is not nullptr, the index
 585   /// of a parameter with the specified attribute is provided.
 586   bool hasAttrSomewhere(Attribute::AttrKind Kind,
 587                         unsigned *Index = nullptr) const;
 588
 589   /// Return the attribute object that exists at the given index.
 590   Attribute getAttribute(unsigned Index, Attribute::AttrKind Kind) const;
 591
 592   /// Return the attribute object that exists at the given index.
 593   Attribute getAttribute(unsigned Index, StringRef Kind) const;
 594
 595   /// Return the attribute object that exists at the arg index.
 596   Attribute getParamAttr(unsigned ArgNo, Attribute::AttrKind Kind) const {
 597     return getAttribute(ArgNo + FirstArgIndex, Kind);
 598   }
 599
 600   /// Return the attribute object that exists at the given index.
 601   Attribute getParamAttr(unsigned ArgNo, StringRef Kind) const {
 602     return getAttribute(ArgNo + FirstArgIndex, Kind);
 603   }
 604
 605   /// Return the alignment of the return value.
 606   unsigned getRetAlignment() const;
 607
 608   /// Return the alignment for the specified function parameter.
 609   unsigned getParamAlignment(unsigned ArgNo) const;
 610
 611   /// Return the byval type for the specified function parameter.
 612   Type *getParamByValType(unsigned ArgNo) const;
 613
 614   /// Get the stack alignment.
 615   unsigned getStackAlignment(unsigned Index) const;
 616
 617   /// Get the number of dereferenceable bytes (or zero if unknown).
 618   uint64_t getDereferenceableBytes(unsigned Index) const;
 619
 620   /// Get the number of dereferenceable bytes (or zero if unknown) of an
 621   /// arg.
 622   uint64_t getParamDereferenceableBytes(unsigned ArgNo) const {
 623     return getDereferenceableBytes(ArgNo + FirstArgIndex);
 624   }
 625
 626   /// Get the number of dereferenceable_or_null bytes (or zero if
 627   /// unknown).
 628   uint64_t getDereferenceableOrNullBytes(unsigned Index) const;
 629
 630   /// Get the number of dereferenceable_or_null bytes (or zero if
 631   /// unknown) of an arg.
 632   uint64_t getParamDereferenceableOrNullBytes(unsigned ArgNo) const {
 633     return getDereferenceableOrNullBytes(ArgNo + FirstArgIndex);
 634   }
 635
 636   /// Get the allocsize argument numbers (or pair(0, 0) if unknown).
 637   std::pair<unsigned, Optional<unsigned>>
 638   getAllocSizeArgs(unsigned Index) const;
 639
 640   /// Return the attributes at the index as a string.
 641   std::string getAsString(unsigned Index, bool InAttrGrp = false) const;
 642
 643   //===--------------------------------------------------------------------===//
 644   // AttributeList Introspection
 645   //===--------------------------------------------------------------------===//
 646
 647   using iterator = const AttributeSet *;
 648
 649   iterator begin() const;
 650   iterator end() const;
 651
 652   unsigned getNumAttrSets() const;
 653
 654   /// Use these to iterate over the valid attribute indices.
 655   unsigned index_begin() const { return AttributeList::FunctionIndex; }
 656   unsigned index_end() const { return getNumAttrSets() - 1; }
 657
 658   /// operator==/!= - Provide equality predicates.
 659   bool operator==(const AttributeList &RHS) const { return pImpl == RHS.pImpl; }
 660   bool operator!=(const AttributeList &RHS) const { return pImpl != RHS.pImpl; }
 661
 662   /// Return a raw pointer that uniquely identifies this attribute list.
 663   void *getRawPointer() const {
 664     return pImpl;
 665   }
 666
 667   /// Return true if there are no attributes.
 668   bool isEmpty() const { return pImpl == nullptr; }
 669
 670   void dump() const;
 671 };
 672
 673 //===----------------------------------------------------------------------===//
 674 /// \class
 675 /// Provide DenseMapInfo for AttributeList.
 676 template <> struct DenseMapInfo<AttributeList> {
 677   static AttributeList getEmptyKey() {
 678     auto Val = static_cast<uintptr_t>(-1);
 679     Val <<= PointerLikeTypeTraits<void*>::NumLowBitsAvailable;
 680     return AttributeList(reinterpret_cast<AttributeListImpl *>(Val));
 681   }
 682
 683   static AttributeList getTombstoneKey() {
 684     auto Val = static_cast<uintptr_t>(-2);
 685     Val <<= PointerLikeTypeTraits<void*>::NumLowBitsAvailable;
 686     return AttributeList(reinterpret_cast<AttributeListImpl *>(Val));
 687   }
 688
 689   static unsigned getHashValue(AttributeList AS) {
 690     return (unsigned((uintptr_t)AS.pImpl) >> 4) ^
 691            (unsigned((uintptr_t)AS.pImpl) >> 9);
 692   }
 693
 694   static bool isEqual(AttributeList LHS, AttributeList RHS) {
 695     return LHS == RHS;
 696   }
 697 };
 698
 699 //===----------------------------------------------------------------------===//
 700 /// \class
 701 /// This class is used in conjunction with the Attribute::get method to
 702 /// create an Attribute object. The object itself is uniquified. The Builder's
 703 /// value, however, is not. So this can be used as a quick way to test for
 704 /// equality, presence of attributes, etc.
 705 class AttrBuilder {
 706   std::bitset<Attribute::EndAttrKinds> Attrs;
 707   std::map<std::string, std::string> TargetDepAttrs;
 708   uint64_t Alignment = 0;
 709   uint64_t StackAlignment = 0;
 710   uint64_t DerefBytes = 0;
 711   uint64_t DerefOrNullBytes = 0;
 712   uint64_t AllocSizeArgs = 0;
 713   Type *ByValType = nullptr;
 714
 715 public:
 716   AttrBuilder() = default;
 717
 718   AttrBuilder(const Attribute &A) {
 719     addAttribute(A);
 720   }
 721
 722   AttrBuilder(AttributeList AS, unsigned Idx);
 723   AttrBuilder(AttributeSet AS);
 724
 725   void clear();
 726
 727   /// Add an attribute to the builder.
 728   AttrBuilder &addAttribute(Attribute::AttrKind Val);
 729
 730   /// Add the Attribute object to the builder.
 731   AttrBuilder &addAttribute(Attribute A);
 732
 733   /// Add the target-dependent attribute to the builder.
 734   AttrBuilder &addAttribute(StringRef A, StringRef V = StringRef());
 735
 736   /// Remove an attribute from the builder.
 737   AttrBuilder &removeAttribute(Attribute::AttrKind Val);
 738
 739   /// Remove the attributes from the builder.
 740   AttrBuilder &removeAttributes(AttributeList A, uint64_t WithoutIndex);
 741
 742   /// Remove the target-dependent attribute to the builder.
 743   AttrBuilder &removeAttribute(StringRef A);
 744
 745   /// Add the attributes from the builder.
 746   AttrBuilder &merge(const AttrBuilder &B);
 747
 748   /// Remove the attributes from the builder.
 749   AttrBuilder &remove(const AttrBuilder &B);
 750
 751   /// Return true if the builder has any attribute that's in the
 752   /// specified builder.
 753   bool overlaps(const AttrBuilder &B) const;
 754
 755   /// Return true if the builder has the specified attribute.
 756   bool contains(Attribute::AttrKind A) const {
 757     assert((unsigned)A < Attribute::EndAttrKinds && "Attribute out of range!");
 758     return Attrs[A];
 759   }
 760
 761   /// Return true if the builder has the specified target-dependent
 762   /// attribute.
 763   bool contains(StringRef A) const;
 764
 765   /// Return true if the builder has IR-level attributes.
 766   bool hasAttributes() const;
 767
 768   /// Return true if the builder has any attribute that's in the
 769   /// specified attribute.
 770   bool hasAttributes(AttributeList A, uint64_t Index) const;
 771
 772   /// Return true if the builder has an alignment attribute.
 773   bool hasAlignmentAttr() const;
 774
 775   /// Retrieve the alignment attribute, if it exists.
 776   uint64_t getAlignment() const { return Alignment; }
 777
 778   /// Retrieve the stack alignment attribute, if it exists.
 779   uint64_t getStackAlignment() const { return StackAlignment; }
 780
 781   /// Retrieve the number of dereferenceable bytes, if the
 782   /// dereferenceable attribute exists (zero is returned otherwise).
 783   uint64_t getDereferenceableBytes() const { return DerefBytes; }
 784
 785   /// Retrieve the number of dereferenceable_or_null bytes, if the
 786   /// dereferenceable_or_null attribute exists (zero is returned otherwise).
 787   uint64_t getDereferenceableOrNullBytes() const { return DerefOrNullBytes; }
 788
 789   /// Retrieve the byval type.
 790   Type *getByValType() const { return ByValType; }
 791
 792   /// Retrieve the allocsize args, if the allocsize attribute exists.  If it
 793   /// doesn't exist, pair(0, 0) is returned.
 794   std::pair<unsigned, Optional<unsigned>> getAllocSizeArgs() const;
 795
 796   /// This turns an int alignment (which must be a power of 2) into the
 797   /// form used internally in Attribute.
 798   AttrBuilder &addAlignmentAttr(unsigned Align);
 799
 800   /// This turns an int stack alignment (which must be a power of 2) into
 801   /// the form used internally in Attribute.
 802   AttrBuilder &addStackAlignmentAttr(unsigned Align);
 803
 804   /// This turns the number of dereferenceable bytes into the form used
 805   /// internally in Attribute.
 806   AttrBuilder &addDereferenceableAttr(uint64_t Bytes);
 807
 808   /// This turns the number of dereferenceable_or_null bytes into the
 809   /// form used internally in Attribute.
 810   AttrBuilder &addDereferenceableOrNullAttr(uint64_t Bytes);
 811
 812   /// This turns one (or two) ints into the form used internally in Attribute.
 813   AttrBuilder &addAllocSizeAttr(unsigned ElemSizeArg,
 814                                 const Optional<unsigned> &NumElemsArg);
 815
 816   /// This turns a byval type into the form used internally in Attribute.
 817   AttrBuilder &addByValAttr(Type *Ty);
 818
 819   /// Add an allocsize attribute, using the representation returned by
 820   /// Attribute.getIntValue().
 821   AttrBuilder &addAllocSizeAttrFromRawRepr(uint64_t RawAllocSizeRepr);
 822
 823   /// Return true if the builder contains no target-independent
 824   /// attributes.
 825   bool empty() const { return Attrs.none(); }
 826
 827   // Iterators for target-dependent attributes.
 828   using td_type = std::pair<std::string, std::string>;
 829   using td_iterator = std::map<std::string, std::string>::iterator;
 830   using td_const_iterator = std::map<std::string, std::string>::const_iterator;
 831   using td_range = iterator_range<td_iterator>;
 832   using td_const_range = iterator_range<td_const_iterator>;
 833
 834   td_iterator td_begin() { return TargetDepAttrs.begin(); }
 835   td_iterator td_end() { return TargetDepAttrs.end(); }
 836
 837   td_const_iterator td_begin() const { return TargetDepAttrs.begin(); }
 838   td_const_iterator td_end() const { return TargetDepAttrs.end(); }
 839
 840   td_range td_attrs() { return td_range(td_begin(), td_end()); }
 841
 842   td_const_range td_attrs() const {
 843     return td_const_range(td_begin(), td_end());
 844   }
 845
 846   bool td_empty() const { return TargetDepAttrs.empty(); }
 847
 848   bool operator==(const AttrBuilder &B);
 849   bool operator!=(const AttrBuilder &B) {
 850     return !(*this == B);
 851   }
 852 };
 853
 854 namespace AttributeFuncs {
 855
 856 /// Which attributes cannot be applied to a type.
 857 AttrBuilder typeIncompatible(Type *Ty);
 858
 859 /// \returns Return true if the two functions have compatible target-independent
 860 /// attributes for inlining purposes.
 861 bool areInlineCompatible(const Function &Caller, const Function &Callee);
 862
 863 /// Merge caller's and callee's attributes.
 864 void mergeAttributesForInlining(Function &Caller, const Function &Callee);
 865
 866 } // end namespace AttributeFuncs
 867
 868 } // end namespace llvm
 869
 870 #endif // LLVM_IR_ATTRIBUTES_H