clang  10.0.0svn
Type.h
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1 //===- Type.h - C Language Family Type Representation -----------*- 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 /// C Language Family Type Representation
11 ///
12 /// This file defines the clang::Type interface and subclasses, used to
13 /// represent types for languages in the C family.
14 //
15 //===----------------------------------------------------------------------===//
16 
17 #ifndef LLVM_CLANG_AST_TYPE_H
18 #define LLVM_CLANG_AST_TYPE_H
19 
21 #include "clang/AST/TemplateName.h"
23 #include "clang/Basic/AttrKinds.h"
24 #include "clang/Basic/Diagnostic.h"
26 #include "clang/Basic/LLVM.h"
27 #include "clang/Basic/Linkage.h"
30 #include "clang/Basic/Specifiers.h"
31 #include "clang/Basic/Visibility.h"
32 #include "llvm/ADT/APInt.h"
33 #include "llvm/ADT/APSInt.h"
34 #include "llvm/ADT/ArrayRef.h"
35 #include "llvm/ADT/FoldingSet.h"
36 #include "llvm/ADT/None.h"
37 #include "llvm/ADT/Optional.h"
38 #include "llvm/ADT/PointerIntPair.h"
39 #include "llvm/ADT/PointerUnion.h"
40 #include "llvm/ADT/StringRef.h"
41 #include "llvm/ADT/Twine.h"
42 #include "llvm/ADT/iterator_range.h"
43 #include "llvm/Support/Casting.h"
44 #include "llvm/Support/Compiler.h"
45 #include "llvm/Support/ErrorHandling.h"
46 #include "llvm/Support/PointerLikeTypeTraits.h"
47 #include "llvm/Support/type_traits.h"
48 #include "llvm/Support/TrailingObjects.h"
49 #include <cassert>
50 #include <cstddef>
51 #include <cstdint>
52 #include <cstring>
53 #include <string>
54 #include <type_traits>
55 #include <utility>
56 
57 namespace clang {
58 
59 class ExtQuals;
60 class QualType;
61 class TagDecl;
62 class Type;
63 
64 enum {
67 };
68 
69 } // namespace clang
70 
71 namespace llvm {
72 
73  template <typename T>
74  struct PointerLikeTypeTraits;
75  template<>
77  static inline void *getAsVoidPointer(::clang::Type *P) { return P; }
78 
80  return static_cast< ::clang::Type*>(P);
81  }
82 
83  enum { NumLowBitsAvailable = clang::TypeAlignmentInBits };
84  };
85 
86  template<>
88  static inline void *getAsVoidPointer(::clang::ExtQuals *P) { return P; }
89 
90  static inline ::clang::ExtQuals *getFromVoidPointer(void *P) {
91  return static_cast< ::clang::ExtQuals*>(P);
92  }
93 
94  enum { NumLowBitsAvailable = clang::TypeAlignmentInBits };
95  };
96 
97 } // namespace llvm
98 
99 namespace clang {
100 
101 class ASTContext;
102 template <typename> class CanQual;
103 class CXXRecordDecl;
104 class DeclContext;
105 class EnumDecl;
106 class Expr;
107 class ExtQualsTypeCommonBase;
108 class FunctionDecl;
109 class IdentifierInfo;
110 class NamedDecl;
111 class ObjCInterfaceDecl;
112 class ObjCProtocolDecl;
113 class ObjCTypeParamDecl;
114 struct PrintingPolicy;
115 class RecordDecl;
116 class Stmt;
117 class TagDecl;
118 class TemplateArgument;
119 class TemplateArgumentListInfo;
120 class TemplateArgumentLoc;
121 class TemplateTypeParmDecl;
122 class TypedefNameDecl;
123 class UnresolvedUsingTypenameDecl;
124 
125 using CanQualType = CanQual<Type>;
126 
127 // Provide forward declarations for all of the *Type classes.
128 #define TYPE(Class, Base) class Class##Type;
129 #include "clang/AST/TypeNodes.inc"
130 
131 /// The collection of all-type qualifiers we support.
132 /// Clang supports five independent qualifiers:
133 /// * C99: const, volatile, and restrict
134 /// * MS: __unaligned
135 /// * Embedded C (TR18037): address spaces
136 /// * Objective C: the GC attributes (none, weak, or strong)
137 class Qualifiers {
138 public:
139  enum TQ { // NOTE: These flags must be kept in sync with DeclSpec::TQ.
140  Const = 0x1,
141  Restrict = 0x2,
142  Volatile = 0x4,
143  CVRMask = Const | Volatile | Restrict
144  };
145 
146  enum GC {
147  GCNone = 0,
149  Strong
150  };
151 
153  /// There is no lifetime qualification on this type.
155 
156  /// This object can be modified without requiring retains or
157  /// releases.
159 
160  /// Assigning into this object requires the old value to be
161  /// released and the new value to be retained. The timing of the
162  /// release of the old value is inexact: it may be moved to
163  /// immediately after the last known point where the value is
164  /// live.
166 
167  /// Reading or writing from this object requires a barrier call.
169 
170  /// Assigning into this object requires a lifetime extension.
171  OCL_Autoreleasing
172  };
173 
174  enum {
175  /// The maximum supported address space number.
176  /// 23 bits should be enough for anyone.
177  MaxAddressSpace = 0x7fffffu,
178 
179  /// The width of the "fast" qualifier mask.
180  FastWidth = 3,
181 
182  /// The fast qualifier mask.
183  FastMask = (1 << FastWidth) - 1
184  };
185 
186  /// Returns the common set of qualifiers while removing them from
187  /// the given sets.
189  // If both are only CVR-qualified, bit operations are sufficient.
190  if (!(L.Mask & ~CVRMask) && !(R.Mask & ~CVRMask)) {
191  Qualifiers Q;
192  Q.Mask = L.Mask & R.Mask;
193  L.Mask &= ~Q.Mask;
194  R.Mask &= ~Q.Mask;
195  return Q;
196  }
197 
198  Qualifiers Q;
199  unsigned CommonCRV = L.getCVRQualifiers() & R.getCVRQualifiers();
200  Q.addCVRQualifiers(CommonCRV);
201  L.removeCVRQualifiers(CommonCRV);
202  R.removeCVRQualifiers(CommonCRV);
203 
204  if (L.getObjCGCAttr() == R.getObjCGCAttr()) {
206  L.removeObjCGCAttr();
207  R.removeObjCGCAttr();
208  }
209 
210  if (L.getObjCLifetime() == R.getObjCLifetime()) {
212  L.removeObjCLifetime();
213  R.removeObjCLifetime();
214  }
215 
216  if (L.getAddressSpace() == R.getAddressSpace()) {
218  L.removeAddressSpace();
219  R.removeAddressSpace();
220  }
221  return Q;
222  }
223 
224  static Qualifiers fromFastMask(unsigned Mask) {
225  Qualifiers Qs;
226  Qs.addFastQualifiers(Mask);
227  return Qs;
228  }
229 
230  static Qualifiers fromCVRMask(unsigned CVR) {
231  Qualifiers Qs;
232  Qs.addCVRQualifiers(CVR);
233  return Qs;
234  }
235 
236  static Qualifiers fromCVRUMask(unsigned CVRU) {
237  Qualifiers Qs;
238  Qs.addCVRUQualifiers(CVRU);
239  return Qs;
240  }
241 
242  // Deserialize qualifiers from an opaque representation.
243  static Qualifiers fromOpaqueValue(unsigned opaque) {
244  Qualifiers Qs;
245  Qs.Mask = opaque;
246  return Qs;
247  }
248 
249  // Serialize these qualifiers into an opaque representation.
250  unsigned getAsOpaqueValue() const {
251  return Mask;
252  }
253 
254  bool hasConst() const { return Mask & Const; }
255  bool hasOnlyConst() const { return Mask == Const; }
256  void removeConst() { Mask &= ~Const; }
257  void addConst() { Mask |= Const; }
258 
259  bool hasVolatile() const { return Mask & Volatile; }
260  bool hasOnlyVolatile() const { return Mask == Volatile; }
261  void removeVolatile() { Mask &= ~Volatile; }
262  void addVolatile() { Mask |= Volatile; }
263 
264  bool hasRestrict() const { return Mask & Restrict; }
265  bool hasOnlyRestrict() const { return Mask == Restrict; }
266  void removeRestrict() { Mask &= ~Restrict; }
267  void addRestrict() { Mask |= Restrict; }
268 
269  bool hasCVRQualifiers() const { return getCVRQualifiers(); }
270  unsigned getCVRQualifiers() const { return Mask & CVRMask; }
271  unsigned getCVRUQualifiers() const { return Mask & (CVRMask | UMask); }
272 
273  void setCVRQualifiers(unsigned mask) {
274  assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits");
275  Mask = (Mask & ~CVRMask) | mask;
276  }
277  void removeCVRQualifiers(unsigned mask) {
278  assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits");
279  Mask &= ~mask;
280  }
282  removeCVRQualifiers(CVRMask);
283  }
284  void addCVRQualifiers(unsigned mask) {
285  assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits");
286  Mask |= mask;
287  }
288  void addCVRUQualifiers(unsigned mask) {
289  assert(!(mask & ~CVRMask & ~UMask) && "bitmask contains non-CVRU bits");
290  Mask |= mask;
291  }
292 
293  bool hasUnaligned() const { return Mask & UMask; }
294  void setUnaligned(bool flag) {
295  Mask = (Mask & ~UMask) | (flag ? UMask : 0);
296  }
297  void removeUnaligned() { Mask &= ~UMask; }
298  void addUnaligned() { Mask |= UMask; }
299 
300  bool hasObjCGCAttr() const { return Mask & GCAttrMask; }
301  GC getObjCGCAttr() const { return GC((Mask & GCAttrMask) >> GCAttrShift); }
303  Mask = (Mask & ~GCAttrMask) | (type << GCAttrShift);
304  }
305  void removeObjCGCAttr() { setObjCGCAttr(GCNone); }
307  assert(type);
308  setObjCGCAttr(type);
309  }
311  Qualifiers qs = *this;
312  qs.removeObjCGCAttr();
313  return qs;
314  }
316  Qualifiers qs = *this;
317  qs.removeObjCLifetime();
318  return qs;
319  }
321  Qualifiers qs = *this;
322  qs.removeAddressSpace();
323  return qs;
324  }
325 
326  bool hasObjCLifetime() const { return Mask & LifetimeMask; }
328  return ObjCLifetime((Mask & LifetimeMask) >> LifetimeShift);
329  }
331  Mask = (Mask & ~LifetimeMask) | (type << LifetimeShift);
332  }
333  void removeObjCLifetime() { setObjCLifetime(OCL_None); }
335  assert(type);
336  assert(!hasObjCLifetime());
337  Mask |= (type << LifetimeShift);
338  }
339 
340  /// True if the lifetime is neither None or ExplicitNone.
342  ObjCLifetime lifetime = getObjCLifetime();
343  return (lifetime > OCL_ExplicitNone);
344  }
345 
346  /// True if the lifetime is either strong or weak.
348  ObjCLifetime lifetime = getObjCLifetime();
349  return (lifetime == OCL_Strong || lifetime == OCL_Weak);
350  }
351 
352  bool hasAddressSpace() const { return Mask & AddressSpaceMask; }
354  return static_cast<LangAS>(Mask >> AddressSpaceShift);
355  }
357  return isTargetAddressSpace(getAddressSpace());
358  }
359  /// Get the address space attribute value to be printed by diagnostics.
361  auto Addr = getAddressSpace();
362  // This function is not supposed to be used with language specific
363  // address spaces. If that happens, the diagnostic message should consider
364  // printing the QualType instead of the address space value.
365  assert(Addr == LangAS::Default || hasTargetSpecificAddressSpace());
366  if (Addr != LangAS::Default)
367  return toTargetAddressSpace(Addr);
368  // TODO: The diagnostic messages where Addr may be 0 should be fixed
369  // since it cannot differentiate the situation where 0 denotes the default
370  // address space or user specified __attribute__((address_space(0))).
371  return 0;
372  }
373  void setAddressSpace(LangAS space) {
374  assert((unsigned)space <= MaxAddressSpace);
375  Mask = (Mask & ~AddressSpaceMask)
376  | (((uint32_t) space) << AddressSpaceShift);
377  }
378  void removeAddressSpace() { setAddressSpace(LangAS::Default); }
379  void addAddressSpace(LangAS space) {
380  assert(space != LangAS::Default);
381  setAddressSpace(space);
382  }
383 
384  // Fast qualifiers are those that can be allocated directly
385  // on a QualType object.
386  bool hasFastQualifiers() const { return getFastQualifiers(); }
387  unsigned getFastQualifiers() const { return Mask & FastMask; }
388  void setFastQualifiers(unsigned mask) {
389  assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits");
390  Mask = (Mask & ~FastMask) | mask;
391  }
392  void removeFastQualifiers(unsigned mask) {
393  assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits");
394  Mask &= ~mask;
395  }
397  removeFastQualifiers(FastMask);
398  }
399  void addFastQualifiers(unsigned mask) {
400  assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits");
401  Mask |= mask;
402  }
403 
404  /// Return true if the set contains any qualifiers which require an ExtQuals
405  /// node to be allocated.
406  bool hasNonFastQualifiers() const { return Mask & ~FastMask; }
408  Qualifiers Quals = *this;
409  Quals.setFastQualifiers(0);
410  return Quals;
411  }
412 
413  /// Return true if the set contains any qualifiers.
414  bool hasQualifiers() const { return Mask; }
415  bool empty() const { return !Mask; }
416 
417  /// Add the qualifiers from the given set to this set.
419  // If the other set doesn't have any non-boolean qualifiers, just
420  // bit-or it in.
421  if (!(Q.Mask & ~CVRMask))
422  Mask |= Q.Mask;
423  else {
424  Mask |= (Q.Mask & CVRMask);
425  if (Q.hasAddressSpace())
426  addAddressSpace(Q.getAddressSpace());
427  if (Q.hasObjCGCAttr())
428  addObjCGCAttr(Q.getObjCGCAttr());
429  if (Q.hasObjCLifetime())
430  addObjCLifetime(Q.getObjCLifetime());
431  }
432  }
433 
434  /// Remove the qualifiers from the given set from this set.
436  // If the other set doesn't have any non-boolean qualifiers, just
437  // bit-and the inverse in.
438  if (!(Q.Mask & ~CVRMask))
439  Mask &= ~Q.Mask;
440  else {
441  Mask &= ~(Q.Mask & CVRMask);
442  if (getObjCGCAttr() == Q.getObjCGCAttr())
443  removeObjCGCAttr();
444  if (getObjCLifetime() == Q.getObjCLifetime())
445  removeObjCLifetime();
446  if (getAddressSpace() == Q.getAddressSpace())
447  removeAddressSpace();
448  }
449  }
450 
451  /// Add the qualifiers from the given set to this set, given that
452  /// they don't conflict.
454  assert(getAddressSpace() == qs.getAddressSpace() ||
455  !hasAddressSpace() || !qs.hasAddressSpace());
456  assert(getObjCGCAttr() == qs.getObjCGCAttr() ||
457  !hasObjCGCAttr() || !qs.hasObjCGCAttr());
458  assert(getObjCLifetime() == qs.getObjCLifetime() ||
459  !hasObjCLifetime() || !qs.hasObjCLifetime());
460  Mask |= qs.Mask;
461  }
462 
463  /// Returns true if address space A is equal to or a superset of B.
464  /// OpenCL v2.0 defines conversion rules (OpenCLC v2.0 s6.5.5) and notion of
465  /// overlapping address spaces.
466  /// CL1.1 or CL1.2:
467  /// every address space is a superset of itself.
468  /// CL2.0 adds:
469  /// __generic is a superset of any address space except for __constant.
471  // Address spaces must match exactly.
472  return A == B ||
473  // Otherwise in OpenCLC v2.0 s6.5.5: every address space except
474  // for __constant can be used as __generic.
476  }
477 
478  /// Returns true if the address space in these qualifiers is equal to or
479  /// a superset of the address space in the argument qualifiers.
481  return isAddressSpaceSupersetOf(getAddressSpace(), other.getAddressSpace());
482  }
483 
484  /// Determines if these qualifiers compatibly include another set.
485  /// Generally this answers the question of whether an object with the other
486  /// qualifiers can be safely used as an object with these qualifiers.
487  bool compatiblyIncludes(Qualifiers other) const {
488  return isAddressSpaceSupersetOf(other) &&
489  // ObjC GC qualifiers can match, be added, or be removed, but can't
490  // be changed.
491  (getObjCGCAttr() == other.getObjCGCAttr() || !hasObjCGCAttr() ||
492  !other.hasObjCGCAttr()) &&
493  // ObjC lifetime qualifiers must match exactly.
494  getObjCLifetime() == other.getObjCLifetime() &&
495  // CVR qualifiers may subset.
496  (((Mask & CVRMask) | (other.Mask & CVRMask)) == (Mask & CVRMask)) &&
497  // U qualifier may superset.
498  (!other.hasUnaligned() || hasUnaligned());
499  }
500 
501  /// Determines if these qualifiers compatibly include another set of
502  /// qualifiers from the narrow perspective of Objective-C ARC lifetime.
503  ///
504  /// One set of Objective-C lifetime qualifiers compatibly includes the other
505  /// if the lifetime qualifiers match, or if both are non-__weak and the
506  /// including set also contains the 'const' qualifier, or both are non-__weak
507  /// and one is None (which can only happen in non-ARC modes).
509  if (getObjCLifetime() == other.getObjCLifetime())
510  return true;
511 
512  if (getObjCLifetime() == OCL_Weak || other.getObjCLifetime() == OCL_Weak)
513  return false;
514 
515  if (getObjCLifetime() == OCL_None || other.getObjCLifetime() == OCL_None)
516  return true;
517 
518  return hasConst();
519  }
520 
521  /// Determine whether this set of qualifiers is a strict superset of
522  /// another set of qualifiers, not considering qualifier compatibility.
523  bool isStrictSupersetOf(Qualifiers Other) const;
524 
525  bool operator==(Qualifiers Other) const { return Mask == Other.Mask; }
526  bool operator!=(Qualifiers Other) const { return Mask != Other.Mask; }
527 
528  explicit operator bool() const { return hasQualifiers(); }
529 
531  addQualifiers(R);
532  return *this;
533  }
534 
535  // Union two qualifier sets. If an enumerated qualifier appears
536  // in both sets, use the one from the right.
538  L += R;
539  return L;
540  }
541 
543  removeQualifiers(R);
544  return *this;
545  }
546 
547  /// Compute the difference between two qualifier sets.
549  L -= R;
550  return L;
551  }
552 
553  std::string getAsString() const;
554  std::string getAsString(const PrintingPolicy &Policy) const;
555 
556  bool isEmptyWhenPrinted(const PrintingPolicy &Policy) const;
557  void print(raw_ostream &OS, const PrintingPolicy &Policy,
558  bool appendSpaceIfNonEmpty = false) const;
559 
560  void Profile(llvm::FoldingSetNodeID &ID) const {
561  ID.AddInteger(Mask);
562  }
563 
564 private:
565  // bits: |0 1 2|3|4 .. 5|6 .. 8|9 ... 31|
566  // |C R V|U|GCAttr|Lifetime|AddressSpace|
567  uint32_t Mask = 0;
568 
569  static const uint32_t UMask = 0x8;
570  static const uint32_t UShift = 3;
571  static const uint32_t GCAttrMask = 0x30;
572  static const uint32_t GCAttrShift = 4;
573  static const uint32_t LifetimeMask = 0x1C0;
574  static const uint32_t LifetimeShift = 6;
575  static const uint32_t AddressSpaceMask =
576  ~(CVRMask | UMask | GCAttrMask | LifetimeMask);
577  static const uint32_t AddressSpaceShift = 9;
578 };
579 
580 /// A std::pair-like structure for storing a qualified type split
581 /// into its local qualifiers and its locally-unqualified type.
583  /// The locally-unqualified type.
584  const Type *Ty = nullptr;
585 
586  /// The local qualifiers.
588 
589  SplitQualType() = default;
590  SplitQualType(const Type *ty, Qualifiers qs) : Ty(ty), Quals(qs) {}
591 
592  SplitQualType getSingleStepDesugaredType() const; // end of this file
593 
594  // Make std::tie work.
595  std::pair<const Type *,Qualifiers> asPair() const {
596  return std::pair<const Type *, Qualifiers>(Ty, Quals);
597  }
598 
600  return a.Ty == b.Ty && a.Quals == b.Quals;
601  }
603  return a.Ty != b.Ty || a.Quals != b.Quals;
604  }
605 };
606 
607 /// The kind of type we are substituting Objective-C type arguments into.
608 ///
609 /// The kind of substitution affects the replacement of type parameters when
610 /// no concrete type information is provided, e.g., when dealing with an
611 /// unspecialized type.
613  /// An ordinary type.
614  Ordinary,
615 
616  /// The result type of a method or function.
617  Result,
618 
619  /// The parameter type of a method or function.
620  Parameter,
621 
622  /// The type of a property.
623  Property,
624 
625  /// The superclass of a type.
626  Superclass,
627 };
628 
629 /// A (possibly-)qualified type.
630 ///
631 /// For efficiency, we don't store CV-qualified types as nodes on their
632 /// own: instead each reference to a type stores the qualifiers. This
633 /// greatly reduces the number of nodes we need to allocate for types (for
634 /// example we only need one for 'int', 'const int', 'volatile int',
635 /// 'const volatile int', etc).
636 ///
637 /// As an added efficiency bonus, instead of making this a pair, we
638 /// just store the two bits we care about in the low bits of the
639 /// pointer. To handle the packing/unpacking, we make QualType be a
640 /// simple wrapper class that acts like a smart pointer. A third bit
641 /// indicates whether there are extended qualifiers present, in which
642 /// case the pointer points to a special structure.
643 class QualType {
644  friend class QualifierCollector;
645 
646  // Thankfully, these are efficiently composable.
647  llvm::PointerIntPair<llvm::PointerUnion<const Type *, const ExtQuals *>,
649 
650  const ExtQuals *getExtQualsUnsafe() const {
651  return Value.getPointer().get<const ExtQuals*>();
652  }
653 
654  const Type *getTypePtrUnsafe() const {
655  return Value.getPointer().get<const Type*>();
656  }
657 
658  const ExtQualsTypeCommonBase *getCommonPtr() const {
659  assert(!isNull() && "Cannot retrieve a NULL type pointer");
660  auto CommonPtrVal = reinterpret_cast<uintptr_t>(Value.getOpaqueValue());
661  CommonPtrVal &= ~(uintptr_t)((1 << TypeAlignmentInBits) - 1);
662  return reinterpret_cast<ExtQualsTypeCommonBase*>(CommonPtrVal);
663  }
664 
665 public:
666  QualType() = default;
667  QualType(const Type *Ptr, unsigned Quals) : Value(Ptr, Quals) {}
668  QualType(const ExtQuals *Ptr, unsigned Quals) : Value(Ptr, Quals) {}
669 
670  unsigned getLocalFastQualifiers() const { return Value.getInt(); }
671  void setLocalFastQualifiers(unsigned Quals) { Value.setInt(Quals); }
672 
673  /// Retrieves a pointer to the underlying (unqualified) type.
674  ///
675  /// This function requires that the type not be NULL. If the type might be
676  /// NULL, use the (slightly less efficient) \c getTypePtrOrNull().
677  const Type *getTypePtr() const;
678 
679  const Type *getTypePtrOrNull() const;
680 
681  /// Retrieves a pointer to the name of the base type.
682  const IdentifierInfo *getBaseTypeIdentifier() const;
683 
684  /// Divides a QualType into its unqualified type and a set of local
685  /// qualifiers.
686  SplitQualType split() const;
687 
688  void *getAsOpaquePtr() const { return Value.getOpaqueValue(); }
689 
690  static QualType getFromOpaquePtr(const void *Ptr) {
691  QualType T;
692  T.Value.setFromOpaqueValue(const_cast<void*>(Ptr));
693  return T;
694  }
695 
696  const Type &operator*() const {
697  return *getTypePtr();
698  }
699 
700  const Type *operator->() const {
701  return getTypePtr();
702  }
703 
704  bool isCanonical() const;
705  bool isCanonicalAsParam() const;
706 
707  /// Return true if this QualType doesn't point to a type yet.
708  bool isNull() const {
709  return Value.getPointer().isNull();
710  }
711 
712  /// Determine whether this particular QualType instance has the
713  /// "const" qualifier set, without looking through typedefs that may have
714  /// added "const" at a different level.
715  bool isLocalConstQualified() const {
716  return (getLocalFastQualifiers() & Qualifiers::Const);
717  }
718 
719  /// Determine whether this type is const-qualified.
720  bool isConstQualified() const;
721 
722  /// Determine whether this particular QualType instance has the
723  /// "restrict" qualifier set, without looking through typedefs that may have
724  /// added "restrict" at a different level.
726  return (getLocalFastQualifiers() & Qualifiers::Restrict);
727  }
728 
729  /// Determine whether this type is restrict-qualified.
730  bool isRestrictQualified() const;
731 
732  /// Determine whether this particular QualType instance has the
733  /// "volatile" qualifier set, without looking through typedefs that may have
734  /// added "volatile" at a different level.
736  return (getLocalFastQualifiers() & Qualifiers::Volatile);
737  }
738 
739  /// Determine whether this type is volatile-qualified.
740  bool isVolatileQualified() const;
741 
742  /// Determine whether this particular QualType instance has any
743  /// qualifiers, without looking through any typedefs that might add
744  /// qualifiers at a different level.
745  bool hasLocalQualifiers() const {
746  return getLocalFastQualifiers() || hasLocalNonFastQualifiers();
747  }
748 
749  /// Determine whether this type has any qualifiers.
750  bool hasQualifiers() const;
751 
752  /// Determine whether this particular QualType instance has any
753  /// "non-fast" qualifiers, e.g., those that are stored in an ExtQualType
754  /// instance.
756  return Value.getPointer().is<const ExtQuals*>();
757  }
758 
759  /// Retrieve the set of qualifiers local to this particular QualType
760  /// instance, not including any qualifiers acquired through typedefs or
761  /// other sugar.
762  Qualifiers getLocalQualifiers() const;
763 
764  /// Retrieve the set of qualifiers applied to this type.
765  Qualifiers getQualifiers() const;
766 
767  /// Retrieve the set of CVR (const-volatile-restrict) qualifiers
768  /// local to this particular QualType instance, not including any qualifiers
769  /// acquired through typedefs or other sugar.
770  unsigned getLocalCVRQualifiers() const {
771  return getLocalFastQualifiers();
772  }
773 
774  /// Retrieve the set of CVR (const-volatile-restrict) qualifiers
775  /// applied to this type.
776  unsigned getCVRQualifiers() const;
777 
778  bool isConstant(const ASTContext& Ctx) const {
779  return QualType::isConstant(*this, Ctx);
780  }
781 
782  /// Determine whether this is a Plain Old Data (POD) type (C++ 3.9p10).
783  bool isPODType(const ASTContext &Context) const;
784 
785  /// Return true if this is a POD type according to the rules of the C++98
786  /// standard, regardless of the current compilation's language.
787  bool isCXX98PODType(const ASTContext &Context) const;
788 
789  /// Return true if this is a POD type according to the more relaxed rules
790  /// of the C++11 standard, regardless of the current compilation's language.
791  /// (C++0x [basic.types]p9). Note that, unlike
792  /// CXXRecordDecl::isCXX11StandardLayout, this takes DRs into account.
793  bool isCXX11PODType(const ASTContext &Context) const;
794 
795  /// Return true if this is a trivial type per (C++0x [basic.types]p9)
796  bool isTrivialType(const ASTContext &Context) const;
797 
798  /// Return true if this is a trivially copyable type (C++0x [basic.types]p9)
799  bool isTriviallyCopyableType(const ASTContext &Context) const;
800 
801 
802  /// Returns true if it is a class and it might be dynamic.
803  bool mayBeDynamicClass() const;
804 
805  /// Returns true if it is not a class or if the class might not be dynamic.
806  bool mayBeNotDynamicClass() const;
807 
808  // Don't promise in the API that anything besides 'const' can be
809  // easily added.
810 
811  /// Add the `const` type qualifier to this QualType.
812  void addConst() {
813  addFastQualifiers(Qualifiers::Const);
814  }
815  QualType withConst() const {
816  return withFastQualifiers(Qualifiers::Const);
817  }
818 
819  /// Add the `volatile` type qualifier to this QualType.
820  void addVolatile() {
821  addFastQualifiers(Qualifiers::Volatile);
822  }
824  return withFastQualifiers(Qualifiers::Volatile);
825  }
826 
827  /// Add the `restrict` qualifier to this QualType.
828  void addRestrict() {
829  addFastQualifiers(Qualifiers::Restrict);
830  }
832  return withFastQualifiers(Qualifiers::Restrict);
833  }
834 
835  QualType withCVRQualifiers(unsigned CVR) const {
836  return withFastQualifiers(CVR);
837  }
838 
839  void addFastQualifiers(unsigned TQs) {
840  assert(!(TQs & ~Qualifiers::FastMask)
841  && "non-fast qualifier bits set in mask!");
842  Value.setInt(Value.getInt() | TQs);
843  }
844 
845  void removeLocalConst();
846  void removeLocalVolatile();
847  void removeLocalRestrict();
848  void removeLocalCVRQualifiers(unsigned Mask);
849 
850  void removeLocalFastQualifiers() { Value.setInt(0); }
851  void removeLocalFastQualifiers(unsigned Mask) {
852  assert(!(Mask & ~Qualifiers::FastMask) && "mask has non-fast qualifiers");
853  Value.setInt(Value.getInt() & ~Mask);
854  }
855 
856  // Creates a type with the given qualifiers in addition to any
857  // qualifiers already on this type.
858  QualType withFastQualifiers(unsigned TQs) const {
859  QualType T = *this;
860  T.addFastQualifiers(TQs);
861  return T;
862  }
863 
864  // Creates a type with exactly the given fast qualifiers, removing
865  // any existing fast qualifiers.
867  return withoutLocalFastQualifiers().withFastQualifiers(TQs);
868  }
869 
870  // Removes fast qualifiers, but leaves any extended qualifiers in place.
872  QualType T = *this;
874  return T;
875  }
876 
877  QualType getCanonicalType() const;
878 
879  /// Return this type with all of the instance-specific qualifiers
880  /// removed, but without removing any qualifiers that may have been applied
881  /// through typedefs.
882  QualType getLocalUnqualifiedType() const { return QualType(getTypePtr(), 0); }
883 
884  /// Retrieve the unqualified variant of the given type,
885  /// removing as little sugar as possible.
886  ///
887  /// This routine looks through various kinds of sugar to find the
888  /// least-desugared type that is unqualified. For example, given:
889  ///
890  /// \code
891  /// typedef int Integer;
892  /// typedef const Integer CInteger;
893  /// typedef CInteger DifferenceType;
894  /// \endcode
895  ///
896  /// Executing \c getUnqualifiedType() on the type \c DifferenceType will
897  /// desugar until we hit the type \c Integer, which has no qualifiers on it.
898  ///
899  /// The resulting type might still be qualified if it's sugar for an array
900  /// type. To strip qualifiers even from within a sugared array type, use
901  /// ASTContext::getUnqualifiedArrayType.
902  inline QualType getUnqualifiedType() const;
903 
904  /// Retrieve the unqualified variant of the given type, removing as little
905  /// sugar as possible.
906  ///
907  /// Like getUnqualifiedType(), but also returns the set of
908  /// qualifiers that were built up.
909  ///
910  /// The resulting type might still be qualified if it's sugar for an array
911  /// type. To strip qualifiers even from within a sugared array type, use
912  /// ASTContext::getUnqualifiedArrayType.
913  inline SplitQualType getSplitUnqualifiedType() const;
914 
915  /// Determine whether this type is more qualified than the other
916  /// given type, requiring exact equality for non-CVR qualifiers.
917  bool isMoreQualifiedThan(QualType Other) const;
918 
919  /// Determine whether this type is at least as qualified as the other
920  /// given type, requiring exact equality for non-CVR qualifiers.
921  bool isAtLeastAsQualifiedAs(QualType Other) const;
922 
923  QualType getNonReferenceType() const;
924 
925  /// Determine the type of a (typically non-lvalue) expression with the
926  /// specified result type.
927  ///
928  /// This routine should be used for expressions for which the return type is
929  /// explicitly specified (e.g., in a cast or call) and isn't necessarily
930  /// an lvalue. It removes a top-level reference (since there are no
931  /// expressions of reference type) and deletes top-level cvr-qualifiers
932  /// from non-class types (in C++) or all types (in C).
933  QualType getNonLValueExprType(const ASTContext &Context) const;
934 
935  /// Return the specified type with any "sugar" removed from
936  /// the type. This takes off typedefs, typeof's etc. If the outer level of
937  /// the type is already concrete, it returns it unmodified. This is similar
938  /// to getting the canonical type, but it doesn't remove *all* typedefs. For
939  /// example, it returns "T*" as "T*", (not as "int*"), because the pointer is
940  /// concrete.
941  ///
942  /// Qualifiers are left in place.
943  QualType getDesugaredType(const ASTContext &Context) const {
944  return getDesugaredType(*this, Context);
945  }
946 
948  return getSplitDesugaredType(*this);
949  }
950 
951  /// Return the specified type with one level of "sugar" removed from
952  /// the type.
953  ///
954  /// This routine takes off the first typedef, typeof, etc. If the outer level
955  /// of the type is already concrete, it returns it unmodified.
957  return getSingleStepDesugaredTypeImpl(*this, Context);
958  }
959 
960  /// Returns the specified type after dropping any
961  /// outer-level parentheses.
963  if (isa<ParenType>(*this))
964  return QualType::IgnoreParens(*this);
965  return *this;
966  }
967 
968  /// Indicate whether the specified types and qualifiers are identical.
969  friend bool operator==(const QualType &LHS, const QualType &RHS) {
970  return LHS.Value == RHS.Value;
971  }
972  friend bool operator!=(const QualType &LHS, const QualType &RHS) {
973  return LHS.Value != RHS.Value;
974  }
975  friend bool operator<(const QualType &LHS, const QualType &RHS) {
976  return LHS.Value < RHS.Value;
977  }
978 
979  static std::string getAsString(SplitQualType split,
980  const PrintingPolicy &Policy) {
981  return getAsString(split.Ty, split.Quals, Policy);
982  }
983  static std::string getAsString(const Type *ty, Qualifiers qs,
984  const PrintingPolicy &Policy);
985 
986  std::string getAsString() const;
987  std::string getAsString(const PrintingPolicy &Policy) const;
988 
989  void print(raw_ostream &OS, const PrintingPolicy &Policy,
990  const Twine &PlaceHolder = Twine(),
991  unsigned Indentation = 0) const;
992 
993  static void print(SplitQualType split, raw_ostream &OS,
994  const PrintingPolicy &policy, const Twine &PlaceHolder,
995  unsigned Indentation = 0) {
996  return print(split.Ty, split.Quals, OS, policy, PlaceHolder, Indentation);
997  }
998 
999  static void print(const Type *ty, Qualifiers qs,
1000  raw_ostream &OS, const PrintingPolicy &policy,
1001  const Twine &PlaceHolder,
1002  unsigned Indentation = 0);
1003 
1004  void getAsStringInternal(std::string &Str,
1005  const PrintingPolicy &Policy) const;
1006 
1007  static void getAsStringInternal(SplitQualType split, std::string &out,
1008  const PrintingPolicy &policy) {
1009  return getAsStringInternal(split.Ty, split.Quals, out, policy);
1010  }
1011 
1012  static void getAsStringInternal(const Type *ty, Qualifiers qs,
1013  std::string &out,
1014  const PrintingPolicy &policy);
1015 
1017  const QualType &T;
1018  const PrintingPolicy &Policy;
1019  const Twine &PlaceHolder;
1020  unsigned Indentation;
1021 
1022  public:
1024  const Twine &PlaceHolder, unsigned Indentation)
1025  : T(T), Policy(Policy), PlaceHolder(PlaceHolder),
1026  Indentation(Indentation) {}
1027 
1028  friend raw_ostream &operator<<(raw_ostream &OS,
1029  const StreamedQualTypeHelper &SQT) {
1030  SQT.T.print(OS, SQT.Policy, SQT.PlaceHolder, SQT.Indentation);
1031  return OS;
1032  }
1033  };
1034 
1036  const Twine &PlaceHolder = Twine(),
1037  unsigned Indentation = 0) const {
1038  return StreamedQualTypeHelper(*this, Policy, PlaceHolder, Indentation);
1039  }
1040 
1041  void dump(const char *s) const;
1042  void dump() const;
1043  void dump(llvm::raw_ostream &OS) const;
1044 
1045  void Profile(llvm::FoldingSetNodeID &ID) const {
1046  ID.AddPointer(getAsOpaquePtr());
1047  }
1048 
1049  /// Return the address space of this type.
1050  inline LangAS getAddressSpace() const;
1051 
1052  /// Returns gc attribute of this type.
1053  inline Qualifiers::GC getObjCGCAttr() const;
1054 
1055  /// true when Type is objc's weak.
1056  bool isObjCGCWeak() const {
1057  return getObjCGCAttr() == Qualifiers::Weak;
1058  }
1059 
1060  /// true when Type is objc's strong.
1061  bool isObjCGCStrong() const {
1062  return getObjCGCAttr() == Qualifiers::Strong;
1063  }
1064 
1065  /// Returns lifetime attribute of this type.
1067  return getQualifiers().getObjCLifetime();
1068  }
1069 
1071  return getQualifiers().hasNonTrivialObjCLifetime();
1072  }
1073 
1075  return getQualifiers().hasStrongOrWeakObjCLifetime();
1076  }
1077 
1078  // true when Type is objc's weak and weak is enabled but ARC isn't.
1079  bool isNonWeakInMRRWithObjCWeak(const ASTContext &Context) const;
1080 
1082  /// The type does not fall into any of the following categories. Note that
1083  /// this case is zero-valued so that values of this enum can be used as a
1084  /// boolean condition for non-triviality.
1086 
1087  /// The type is an Objective-C retainable pointer type that is qualified
1088  /// with the ARC __strong qualifier.
1090 
1091  /// The type is an Objective-C retainable pointer type that is qualified
1092  /// with the ARC __weak qualifier.
1094 
1095  /// The type is a struct containing a field whose type is not PCK_Trivial.
1096  PDIK_Struct
1097  };
1098 
1099  /// Functions to query basic properties of non-trivial C struct types.
1100 
1101  /// Check if this is a non-trivial type that would cause a C struct
1102  /// transitively containing this type to be non-trivial to default initialize
1103  /// and return the kind.
1105  isNonTrivialToPrimitiveDefaultInitialize() const;
1106 
1108  /// The type does not fall into any of the following categories. Note that
1109  /// this case is zero-valued so that values of this enum can be used as a
1110  /// boolean condition for non-triviality.
1112 
1113  /// The type would be trivial except that it is volatile-qualified. Types
1114  /// that fall into one of the other non-trivial cases may additionally be
1115  /// volatile-qualified.
1117 
1118  /// The type is an Objective-C retainable pointer type that is qualified
1119  /// with the ARC __strong qualifier.
1121 
1122  /// The type is an Objective-C retainable pointer type that is qualified
1123  /// with the ARC __weak qualifier.
1125 
1126  /// The type is a struct containing a field whose type is neither
1127  /// PCK_Trivial nor PCK_VolatileTrivial.
1128  /// Note that a C++ struct type does not necessarily match this; C++ copying
1129  /// semantics are too complex to express here, in part because they depend
1130  /// on the exact constructor or assignment operator that is chosen by
1131  /// overload resolution to do the copy.
1132  PCK_Struct
1133  };
1134 
1135  /// Check if this is a non-trivial type that would cause a C struct
1136  /// transitively containing this type to be non-trivial to copy and return the
1137  /// kind.
1138  PrimitiveCopyKind isNonTrivialToPrimitiveCopy() const;
1139 
1140  /// Check if this is a non-trivial type that would cause a C struct
1141  /// transitively containing this type to be non-trivial to destructively
1142  /// move and return the kind. Destructive move in this context is a C++-style
1143  /// move in which the source object is placed in a valid but unspecified state
1144  /// after it is moved, as opposed to a truly destructive move in which the
1145  /// source object is placed in an uninitialized state.
1146  PrimitiveCopyKind isNonTrivialToPrimitiveDestructiveMove() const;
1147 
1153  DK_nontrivial_c_struct
1154  };
1155 
1156  /// Returns a nonzero value if objects of this type require
1157  /// non-trivial work to clean up after. Non-zero because it's
1158  /// conceivable that qualifiers (objc_gc(weak)?) could make
1159  /// something require destruction.
1161  return isDestructedTypeImpl(*this);
1162  }
1163 
1164  /// Check if this is or contains a C union that is non-trivial to
1165  /// default-initialize, which is a union that has a member that is non-trivial
1166  /// to default-initialize. If this returns true,
1167  /// isNonTrivialToPrimitiveDefaultInitialize returns PDIK_Struct.
1168  bool hasNonTrivialToPrimitiveDefaultInitializeCUnion() const;
1169 
1170  /// Check if this is or contains a C union that is non-trivial to destruct,
1171  /// which is a union that has a member that is non-trivial to destruct. If
1172  /// this returns true, isDestructedType returns DK_nontrivial_c_struct.
1173  bool hasNonTrivialToPrimitiveDestructCUnion() const;
1174 
1175  /// Check if this is or contains a C union that is non-trivial to copy, which
1176  /// is a union that has a member that is non-trivial to copy. If this returns
1177  /// true, isNonTrivialToPrimitiveCopy returns PCK_Struct.
1178  bool hasNonTrivialToPrimitiveCopyCUnion() const;
1179 
1180  /// Determine whether expressions of the given type are forbidden
1181  /// from being lvalues in C.
1182  ///
1183  /// The expression types that are forbidden to be lvalues are:
1184  /// - 'void', but not qualified void
1185  /// - function types
1186  ///
1187  /// The exact rule here is C99 6.3.2.1:
1188  /// An lvalue is an expression with an object type or an incomplete
1189  /// type other than void.
1190  bool isCForbiddenLValueType() const;
1191 
1192  /// Substitute type arguments for the Objective-C type parameters used in the
1193  /// subject type.
1194  ///
1195  /// \param ctx ASTContext in which the type exists.
1196  ///
1197  /// \param typeArgs The type arguments that will be substituted for the
1198  /// Objective-C type parameters in the subject type, which are generally
1199  /// computed via \c Type::getObjCSubstitutions. If empty, the type
1200  /// parameters will be replaced with their bounds or id/Class, as appropriate
1201  /// for the context.
1202  ///
1203  /// \param context The context in which the subject type was written.
1204  ///
1205  /// \returns the resulting type.
1206  QualType substObjCTypeArgs(ASTContext &ctx,
1207  ArrayRef<QualType> typeArgs,
1208  ObjCSubstitutionContext context) const;
1209 
1210  /// Substitute type arguments from an object type for the Objective-C type
1211  /// parameters used in the subject type.
1212  ///
1213  /// This operation combines the computation of type arguments for
1214  /// substitution (\c Type::getObjCSubstitutions) with the actual process of
1215  /// substitution (\c QualType::substObjCTypeArgs) for the convenience of
1216  /// callers that need to perform a single substitution in isolation.
1217  ///
1218  /// \param objectType The type of the object whose member type we're
1219  /// substituting into. For example, this might be the receiver of a message
1220  /// or the base of a property access.
1221  ///
1222  /// \param dc The declaration context from which the subject type was
1223  /// retrieved, which indicates (for example) which type parameters should
1224  /// be substituted.
1225  ///
1226  /// \param context The context in which the subject type was written.
1227  ///
1228  /// \returns the subject type after replacing all of the Objective-C type
1229  /// parameters with their corresponding arguments.
1230  QualType substObjCMemberType(QualType objectType,
1231  const DeclContext *dc,
1232  ObjCSubstitutionContext context) const;
1233 
1234  /// Strip Objective-C "__kindof" types from the given type.
1235  QualType stripObjCKindOfType(const ASTContext &ctx) const;
1236 
1237  /// Remove all qualifiers including _Atomic.
1238  QualType getAtomicUnqualifiedType() const;
1239 
1240 private:
1241  // These methods are implemented in a separate translation unit;
1242  // "static"-ize them to avoid creating temporary QualTypes in the
1243  // caller.
1244  static bool isConstant(QualType T, const ASTContext& Ctx);
1245  static QualType getDesugaredType(QualType T, const ASTContext &Context);
1246  static SplitQualType getSplitDesugaredType(QualType T);
1247  static SplitQualType getSplitUnqualifiedTypeImpl(QualType type);
1248  static QualType getSingleStepDesugaredTypeImpl(QualType type,
1249  const ASTContext &C);
1250  static QualType IgnoreParens(QualType T);
1251  static DestructionKind isDestructedTypeImpl(QualType type);
1252 
1253  /// Check if \param RD is or contains a non-trivial C union.
1254  static bool hasNonTrivialToPrimitiveDefaultInitializeCUnion(const RecordDecl *RD);
1255  static bool hasNonTrivialToPrimitiveDestructCUnion(const RecordDecl *RD);
1256  static bool hasNonTrivialToPrimitiveCopyCUnion(const RecordDecl *RD);
1257 };
1258 
1259 } // namespace clang
1260 
1261 namespace llvm {
1262 
1263 /// Implement simplify_type for QualType, so that we can dyn_cast from QualType
1264 /// to a specific Type class.
1265 template<> struct simplify_type< ::clang::QualType> {
1267 
1269  return Val.getTypePtr();
1270  }
1271 };
1272 
1273 // Teach SmallPtrSet that QualType is "basically a pointer".
1274 template<>
1275 struct PointerLikeTypeTraits<clang::QualType> {
1276  static inline void *getAsVoidPointer(clang::QualType P) {
1277  return P.getAsOpaquePtr();
1278  }
1279 
1280  static inline clang::QualType getFromVoidPointer(void *P) {
1282  }
1283 
1284  // Various qualifiers go in low bits.
1285  enum { NumLowBitsAvailable = 0 };
1286 };
1287 
1288 } // namespace llvm
1289 
1290 namespace clang {
1291 
1292 /// Base class that is common to both the \c ExtQuals and \c Type
1293 /// classes, which allows \c QualType to access the common fields between the
1294 /// two.
1296  friend class ExtQuals;
1297  friend class QualType;
1298  friend class Type;
1299 
1300  /// The "base" type of an extended qualifiers type (\c ExtQuals) or
1301  /// a self-referential pointer (for \c Type).
1302  ///
1303  /// This pointer allows an efficient mapping from a QualType to its
1304  /// underlying type pointer.
1305  const Type *const BaseType;
1306 
1307  /// The canonical type of this type. A QualType.
1308  QualType CanonicalType;
1309 
1310  ExtQualsTypeCommonBase(const Type *baseType, QualType canon)
1311  : BaseType(baseType), CanonicalType(canon) {}
1312 };
1313 
1314 /// We can encode up to four bits in the low bits of a
1315 /// type pointer, but there are many more type qualifiers that we want
1316 /// to be able to apply to an arbitrary type. Therefore we have this
1317 /// struct, intended to be heap-allocated and used by QualType to
1318 /// store qualifiers.
1319 ///
1320 /// The current design tags the 'const', 'restrict', and 'volatile' qualifiers
1321 /// in three low bits on the QualType pointer; a fourth bit records whether
1322 /// the pointer is an ExtQuals node. The extended qualifiers (address spaces,
1323 /// Objective-C GC attributes) are much more rare.
1324 class ExtQuals : public ExtQualsTypeCommonBase, public llvm::FoldingSetNode {
1325  // NOTE: changing the fast qualifiers should be straightforward as
1326  // long as you don't make 'const' non-fast.
1327  // 1. Qualifiers:
1328  // a) Modify the bitmasks (Qualifiers::TQ and DeclSpec::TQ).
1329  // Fast qualifiers must occupy the low-order bits.
1330  // b) Update Qualifiers::FastWidth and FastMask.
1331  // 2. QualType:
1332  // a) Update is{Volatile,Restrict}Qualified(), defined inline.
1333  // b) Update remove{Volatile,Restrict}, defined near the end of
1334  // this header.
1335  // 3. ASTContext:
1336  // a) Update get{Volatile,Restrict}Type.
1337 
1338  /// The immutable set of qualifiers applied by this node. Always contains
1339  /// extended qualifiers.
1340  Qualifiers Quals;
1341 
1342  ExtQuals *this_() { return this; }
1343 
1344 public:
1345  ExtQuals(const Type *baseType, QualType canon, Qualifiers quals)
1346  : ExtQualsTypeCommonBase(baseType,
1347  canon.isNull() ? QualType(this_(), 0) : canon),
1348  Quals(quals) {
1349  assert(Quals.hasNonFastQualifiers()
1350  && "ExtQuals created with no fast qualifiers");
1351  assert(!Quals.hasFastQualifiers()
1352  && "ExtQuals created with fast qualifiers");
1353  }
1354 
1355  Qualifiers getQualifiers() const { return Quals; }
1356 
1357  bool hasObjCGCAttr() const { return Quals.hasObjCGCAttr(); }
1358  Qualifiers::GC getObjCGCAttr() const { return Quals.getObjCGCAttr(); }
1359 
1360  bool hasObjCLifetime() const { return Quals.hasObjCLifetime(); }
1362  return Quals.getObjCLifetime();
1363  }
1364 
1365  bool hasAddressSpace() const { return Quals.hasAddressSpace(); }
1366  LangAS getAddressSpace() const { return Quals.getAddressSpace(); }
1367 
1368  const Type *getBaseType() const { return BaseType; }
1369 
1370 public:
1371  void Profile(llvm::FoldingSetNodeID &ID) const {
1372  Profile(ID, getBaseType(), Quals);
1373  }
1374 
1375  static void Profile(llvm::FoldingSetNodeID &ID,
1376  const Type *BaseType,
1377  Qualifiers Quals) {
1378  assert(!Quals.hasFastQualifiers() && "fast qualifiers in ExtQuals hash!");
1379  ID.AddPointer(BaseType);
1380  Quals.Profile(ID);
1381  }
1382 };
1383 
1384 /// The kind of C++11 ref-qualifier associated with a function type.
1385 /// This determines whether a member function's "this" object can be an
1386 /// lvalue, rvalue, or neither.
1388  /// No ref-qualifier was provided.
1389  RQ_None = 0,
1390 
1391  /// An lvalue ref-qualifier was provided (\c &).
1393 
1394  /// An rvalue ref-qualifier was provided (\c &&).
1396 };
1397 
1398 /// Which keyword(s) were used to create an AutoType.
1399 enum class AutoTypeKeyword {
1400  /// auto
1401  Auto,
1402 
1403  /// decltype(auto)
1404  DecltypeAuto,
1405 
1406  /// __auto_type (GNU extension)
1407  GNUAutoType
1408 };
1409 
1410 /// The base class of the type hierarchy.
1411 ///
1412 /// A central concept with types is that each type always has a canonical
1413 /// type. A canonical type is the type with any typedef names stripped out
1414 /// of it or the types it references. For example, consider:
1415 ///
1416 /// typedef int foo;
1417 /// typedef foo* bar;
1418 /// 'int *' 'foo *' 'bar'
1419 ///
1420 /// There will be a Type object created for 'int'. Since int is canonical, its
1421 /// CanonicalType pointer points to itself. There is also a Type for 'foo' (a
1422 /// TypedefType). Its CanonicalType pointer points to the 'int' Type. Next
1423 /// there is a PointerType that represents 'int*', which, like 'int', is
1424 /// canonical. Finally, there is a PointerType type for 'foo*' whose canonical
1425 /// type is 'int*', and there is a TypedefType for 'bar', whose canonical type
1426 /// is also 'int*'.
1427 ///
1428 /// Non-canonical types are useful for emitting diagnostics, without losing
1429 /// information about typedefs being used. Canonical types are useful for type
1430 /// comparisons (they allow by-pointer equality tests) and useful for reasoning
1431 /// about whether something has a particular form (e.g. is a function type),
1432 /// because they implicitly, recursively, strip all typedefs out of a type.
1433 ///
1434 /// Types, once created, are immutable.
1435 ///
1436 class alignas(8) Type : public ExtQualsTypeCommonBase {
1437 public:
1438  enum TypeClass {
1439 #define TYPE(Class, Base) Class,
1440 #define LAST_TYPE(Class) TypeLast = Class
1441 #define ABSTRACT_TYPE(Class, Base)
1442 #include "clang/AST/TypeNodes.inc"
1443  };
1444 
1445 private:
1446  /// Bitfields required by the Type class.
1447  class TypeBitfields {
1448  friend class Type;
1449  template <class T> friend class TypePropertyCache;
1450 
1451  /// TypeClass bitfield - Enum that specifies what subclass this belongs to.
1452  unsigned TC : 8;
1453 
1454  /// Whether this type is a dependent type (C++ [temp.dep.type]).
1455  unsigned Dependent : 1;
1456 
1457  /// Whether this type somehow involves a template parameter, even
1458  /// if the resolution of the type does not depend on a template parameter.
1459  unsigned InstantiationDependent : 1;
1460 
1461  /// Whether this type is a variably-modified type (C99 6.7.5).
1462  unsigned VariablyModified : 1;
1463 
1464  /// Whether this type contains an unexpanded parameter pack
1465  /// (for C++11 variadic templates).
1466  unsigned ContainsUnexpandedParameterPack : 1;
1467 
1468  /// True if the cache (i.e. the bitfields here starting with
1469  /// 'Cache') is valid.
1470  mutable unsigned CacheValid : 1;
1471 
1472  /// Linkage of this type.
1473  mutable unsigned CachedLinkage : 3;
1474 
1475  /// Whether this type involves and local or unnamed types.
1476  mutable unsigned CachedLocalOrUnnamed : 1;
1477 
1478  /// Whether this type comes from an AST file.
1479  mutable unsigned FromAST : 1;
1480 
1481  bool isCacheValid() const {
1482  return CacheValid;
1483  }
1484 
1485  Linkage getLinkage() const {
1486  assert(isCacheValid() && "getting linkage from invalid cache");
1487  return static_cast<Linkage>(CachedLinkage);
1488  }
1489 
1490  bool hasLocalOrUnnamedType() const {
1491  assert(isCacheValid() && "getting linkage from invalid cache");
1492  return CachedLocalOrUnnamed;
1493  }
1494  };
1495  enum { NumTypeBits = 18 };
1496 
1497 protected:
1498  // These classes allow subclasses to somewhat cleanly pack bitfields
1499  // into Type.
1500 
1502  friend class ArrayType;
1503 
1504  unsigned : NumTypeBits;
1505 
1506  /// CVR qualifiers from declarations like
1507  /// 'int X[static restrict 4]'. For function parameters only.
1508  unsigned IndexTypeQuals : 3;
1509 
1510  /// Storage class qualifiers from declarations like
1511  /// 'int X[static restrict 4]'. For function parameters only.
1512  /// Actually an ArrayType::ArraySizeModifier.
1513  unsigned SizeModifier : 3;
1514  };
1515 
1517  friend class ConstantArrayType;
1518 
1519  unsigned : NumTypeBits + 3 + 3;
1520 
1521  /// Whether we have a stored size expression.
1522  unsigned HasStoredSizeExpr : 1;
1523  };
1524 
1526  friend class BuiltinType;
1527 
1528  unsigned : NumTypeBits;
1529 
1530  /// The kind (BuiltinType::Kind) of builtin type this is.
1531  unsigned Kind : 8;
1532  };
1533 
1534  /// FunctionTypeBitfields store various bits belonging to FunctionProtoType.
1535  /// Only common bits are stored here. Additional uncommon bits are stored
1536  /// in a trailing object after FunctionProtoType.
1538  friend class FunctionProtoType;
1539  friend class FunctionType;
1540 
1541  unsigned : NumTypeBits;
1542 
1543  /// Extra information which affects how the function is called, like
1544  /// regparm and the calling convention.
1545  unsigned ExtInfo : 12;
1546 
1547  /// The ref-qualifier associated with a \c FunctionProtoType.
1548  ///
1549  /// This is a value of type \c RefQualifierKind.
1550  unsigned RefQualifier : 2;
1551 
1552  /// Used only by FunctionProtoType, put here to pack with the
1553  /// other bitfields.
1554  /// The qualifiers are part of FunctionProtoType because...
1555  ///
1556  /// C++ 8.3.5p4: The return type, the parameter type list and the
1557  /// cv-qualifier-seq, [...], are part of the function type.
1558  unsigned FastTypeQuals : Qualifiers::FastWidth;
1559  /// Whether this function has extended Qualifiers.
1560  unsigned HasExtQuals : 1;
1561 
1562  /// The number of parameters this function has, not counting '...'.
1563  /// According to [implimits] 8 bits should be enough here but this is
1564  /// somewhat easy to exceed with metaprogramming and so we would like to
1565  /// keep NumParams as wide as reasonably possible.
1566  unsigned NumParams : 16;
1567 
1568  /// The type of exception specification this function has.
1569  unsigned ExceptionSpecType : 4;
1570 
1571  /// Whether this function has extended parameter information.
1572  unsigned HasExtParameterInfos : 1;
1573 
1574  /// Whether the function is variadic.
1575  unsigned Variadic : 1;
1576 
1577  /// Whether this function has a trailing return type.
1578  unsigned HasTrailingReturn : 1;
1579  };
1580 
1582  friend class ObjCObjectType;
1583 
1584  unsigned : NumTypeBits;
1585 
1586  /// The number of type arguments stored directly on this object type.
1587  unsigned NumTypeArgs : 7;
1588 
1589  /// The number of protocols stored directly on this object type.
1590  unsigned NumProtocols : 6;
1591 
1592  /// Whether this is a "kindof" type.
1593  unsigned IsKindOf : 1;
1594  };
1595 
1597  friend class ReferenceType;
1598 
1599  unsigned : NumTypeBits;
1600 
1601  /// True if the type was originally spelled with an lvalue sigil.
1602  /// This is never true of rvalue references but can also be false
1603  /// on lvalue references because of C++0x [dcl.typedef]p9,
1604  /// as follows:
1605  ///
1606  /// typedef int &ref; // lvalue, spelled lvalue
1607  /// typedef int &&rvref; // rvalue
1608  /// ref &a; // lvalue, inner ref, spelled lvalue
1609  /// ref &&a; // lvalue, inner ref
1610  /// rvref &a; // lvalue, inner ref, spelled lvalue
1611  /// rvref &&a; // rvalue, inner ref
1612  unsigned SpelledAsLValue : 1;
1613 
1614  /// True if the inner type is a reference type. This only happens
1615  /// in non-canonical forms.
1616  unsigned InnerRef : 1;
1617  };
1618 
1620  friend class TypeWithKeyword;
1621 
1622  unsigned : NumTypeBits;
1623 
1624  /// An ElaboratedTypeKeyword. 8 bits for efficient access.
1625  unsigned Keyword : 8;
1626  };
1627 
1628  enum { NumTypeWithKeywordBits = 8 };
1629 
1631  friend class ElaboratedType;
1632 
1633  unsigned : NumTypeBits;
1634  unsigned : NumTypeWithKeywordBits;
1635 
1636  /// Whether the ElaboratedType has a trailing OwnedTagDecl.
1637  unsigned HasOwnedTagDecl : 1;
1638  };
1639 
1641  friend class VectorType;
1642  friend class DependentVectorType;
1643 
1644  unsigned : NumTypeBits;
1645 
1646  /// The kind of vector, either a generic vector type or some
1647  /// target-specific vector type such as for AltiVec or Neon.
1648  unsigned VecKind : 3;
1649 
1650  /// The number of elements in the vector.
1651  unsigned NumElements : 29 - NumTypeBits;
1652 
1653  enum { MaxNumElements = (1 << (29 - NumTypeBits)) - 1 };
1654  };
1655 
1657  friend class AttributedType;
1658 
1659  unsigned : NumTypeBits;
1660 
1661  /// An AttributedType::Kind
1662  unsigned AttrKind : 32 - NumTypeBits;
1663  };
1664 
1666  friend class AutoType;
1667 
1668  unsigned : NumTypeBits;
1669 
1670  /// Was this placeholder type spelled as 'auto', 'decltype(auto)',
1671  /// or '__auto_type'? AutoTypeKeyword value.
1672  unsigned Keyword : 2;
1673  };
1674 
1677 
1678  unsigned : NumTypeBits;
1679 
1680  /// The number of template arguments in \c Arguments, which is
1681  /// expected to be able to hold at least 1024 according to [implimits].
1682  /// However as this limit is somewhat easy to hit with template
1683  /// metaprogramming we'd prefer to keep it as large as possible.
1684  /// At the moment it has been left as a non-bitfield since this type
1685  /// safely fits in 64 bits as an unsigned, so there is no reason to
1686  /// introduce the performance impact of a bitfield.
1687  unsigned NumArgs;
1688  };
1689 
1692 
1693  unsigned : NumTypeBits;
1694 
1695  /// Whether this template specialization type is a substituted type alias.
1696  unsigned TypeAlias : 1;
1697 
1698  /// The number of template arguments named in this class template
1699  /// specialization, which is expected to be able to hold at least 1024
1700  /// according to [implimits]. However, as this limit is somewhat easy to
1701  /// hit with template metaprogramming we'd prefer to keep it as large
1702  /// as possible. At the moment it has been left as a non-bitfield since
1703  /// this type safely fits in 64 bits as an unsigned, so there is no reason
1704  /// to introduce the performance impact of a bitfield.
1705  unsigned NumArgs;
1706  };
1707 
1710 
1711  unsigned : NumTypeBits;
1712  unsigned : NumTypeWithKeywordBits;
1713 
1714  /// The number of template arguments named in this class template
1715  /// specialization, which is expected to be able to hold at least 1024
1716  /// according to [implimits]. However, as this limit is somewhat easy to
1717  /// hit with template metaprogramming we'd prefer to keep it as large
1718  /// as possible. At the moment it has been left as a non-bitfield since
1719  /// this type safely fits in 64 bits as an unsigned, so there is no reason
1720  /// to introduce the performance impact of a bitfield.
1721  unsigned NumArgs;
1722  };
1723 
1725  friend class PackExpansionType;
1726 
1727  unsigned : NumTypeBits;
1728 
1729  /// The number of expansions that this pack expansion will
1730  /// generate when substituted (+1), which is expected to be able to
1731  /// hold at least 1024 according to [implimits]. However, as this limit
1732  /// is somewhat easy to hit with template metaprogramming we'd prefer to
1733  /// keep it as large as possible. At the moment it has been left as a
1734  /// non-bitfield since this type safely fits in 64 bits as an unsigned, so
1735  /// there is no reason to introduce the performance impact of a bitfield.
1736  ///
1737  /// This field will only have a non-zero value when some of the parameter
1738  /// packs that occur within the pattern have been substituted but others
1739  /// have not.
1740  unsigned NumExpansions;
1741  };
1742 
1743  union {
1744  TypeBitfields TypeBits;
1761 
1762  static_assert(sizeof(TypeBitfields) <= 8,
1763  "TypeBitfields is larger than 8 bytes!");
1764  static_assert(sizeof(ArrayTypeBitfields) <= 8,
1765  "ArrayTypeBitfields is larger than 8 bytes!");
1766  static_assert(sizeof(AttributedTypeBitfields) <= 8,
1767  "AttributedTypeBitfields is larger than 8 bytes!");
1768  static_assert(sizeof(AutoTypeBitfields) <= 8,
1769  "AutoTypeBitfields is larger than 8 bytes!");
1770  static_assert(sizeof(BuiltinTypeBitfields) <= 8,
1771  "BuiltinTypeBitfields is larger than 8 bytes!");
1772  static_assert(sizeof(FunctionTypeBitfields) <= 8,
1773  "FunctionTypeBitfields is larger than 8 bytes!");
1774  static_assert(sizeof(ObjCObjectTypeBitfields) <= 8,
1775  "ObjCObjectTypeBitfields is larger than 8 bytes!");
1776  static_assert(sizeof(ReferenceTypeBitfields) <= 8,
1777  "ReferenceTypeBitfields is larger than 8 bytes!");
1778  static_assert(sizeof(TypeWithKeywordBitfields) <= 8,
1779  "TypeWithKeywordBitfields is larger than 8 bytes!");
1780  static_assert(sizeof(ElaboratedTypeBitfields) <= 8,
1781  "ElaboratedTypeBitfields is larger than 8 bytes!");
1782  static_assert(sizeof(VectorTypeBitfields) <= 8,
1783  "VectorTypeBitfields is larger than 8 bytes!");
1784  static_assert(sizeof(SubstTemplateTypeParmPackTypeBitfields) <= 8,
1785  "SubstTemplateTypeParmPackTypeBitfields is larger"
1786  " than 8 bytes!");
1787  static_assert(sizeof(TemplateSpecializationTypeBitfields) <= 8,
1788  "TemplateSpecializationTypeBitfields is larger"
1789  " than 8 bytes!");
1790  static_assert(sizeof(DependentTemplateSpecializationTypeBitfields) <= 8,
1791  "DependentTemplateSpecializationTypeBitfields is larger"
1792  " than 8 bytes!");
1793  static_assert(sizeof(PackExpansionTypeBitfields) <= 8,
1794  "PackExpansionTypeBitfields is larger than 8 bytes");
1795  };
1796 
1797 private:
1798  template <class T> friend class TypePropertyCache;
1799 
1800  /// Set whether this type comes from an AST file.
1801  void setFromAST(bool V = true) const {
1802  TypeBits.FromAST = V;
1803  }
1804 
1805 protected:
1806  friend class ASTContext;
1807 
1808  Type(TypeClass tc, QualType canon, bool Dependent,
1809  bool InstantiationDependent, bool VariablyModified,
1810  bool ContainsUnexpandedParameterPack)
1811  : ExtQualsTypeCommonBase(this,
1812  canon.isNull() ? QualType(this_(), 0) : canon) {
1813  TypeBits.TC = tc;
1814  TypeBits.Dependent = Dependent;
1815  TypeBits.InstantiationDependent = Dependent || InstantiationDependent;
1816  TypeBits.VariablyModified = VariablyModified;
1817  TypeBits.ContainsUnexpandedParameterPack = ContainsUnexpandedParameterPack;
1818  TypeBits.CacheValid = false;
1819  TypeBits.CachedLocalOrUnnamed = false;
1820  TypeBits.CachedLinkage = NoLinkage;
1821  TypeBits.FromAST = false;
1822  }
1823 
1824  // silence VC++ warning C4355: 'this' : used in base member initializer list
1825  Type *this_() { return this; }
1826 
1827  void setDependent(bool D = true) {
1828  TypeBits.Dependent = D;
1829  if (D)
1830  TypeBits.InstantiationDependent = true;
1831  }
1832 
1833  void setInstantiationDependent(bool D = true) {
1834  TypeBits.InstantiationDependent = D; }
1835 
1836  void setVariablyModified(bool VM = true) { TypeBits.VariablyModified = VM; }
1837 
1838  void setContainsUnexpandedParameterPack(bool PP = true) {
1839  TypeBits.ContainsUnexpandedParameterPack = PP;
1840  }
1841 
1842 public:
1843  friend class ASTReader;
1844  friend class ASTWriter;
1845 
1846  Type(const Type &) = delete;
1847  Type(Type &&) = delete;
1848  Type &operator=(const Type &) = delete;
1849  Type &operator=(Type &&) = delete;
1850 
1851  TypeClass getTypeClass() const { return static_cast<TypeClass>(TypeBits.TC); }
1852 
1853  /// Whether this type comes from an AST file.
1854  bool isFromAST() const { return TypeBits.FromAST; }
1855 
1856  /// Whether this type is or contains an unexpanded parameter
1857  /// pack, used to support C++0x variadic templates.
1858  ///
1859  /// A type that contains a parameter pack shall be expanded by the
1860  /// ellipsis operator at some point. For example, the typedef in the
1861  /// following example contains an unexpanded parameter pack 'T':
1862  ///
1863  /// \code
1864  /// template<typename ...T>
1865  /// struct X {
1866  /// typedef T* pointer_types; // ill-formed; T is a parameter pack.
1867  /// };
1868  /// \endcode
1869  ///
1870  /// Note that this routine does not specify which
1872  return TypeBits.ContainsUnexpandedParameterPack;
1873  }
1874 
1875  /// Determines if this type would be canonical if it had no further
1876  /// qualification.
1877  bool isCanonicalUnqualified() const {
1878  return CanonicalType == QualType(this, 0);
1879  }
1880 
1881  /// Pull a single level of sugar off of this locally-unqualified type.
1882  /// Users should generally prefer SplitQualType::getSingleStepDesugaredType()
1883  /// or QualType::getSingleStepDesugaredType(const ASTContext&).
1884  QualType getLocallyUnqualifiedSingleStepDesugaredType() const;
1885 
1886  /// Types are partitioned into 3 broad categories (C99 6.2.5p1):
1887  /// object types, function types, and incomplete types.
1888 
1889  /// Return true if this is an incomplete type.
1890  /// A type that can describe objects, but which lacks information needed to
1891  /// determine its size (e.g. void, or a fwd declared struct). Clients of this
1892  /// routine will need to determine if the size is actually required.
1893  ///
1894  /// Def If non-null, and the type refers to some kind of declaration
1895  /// that can be completed (such as a C struct, C++ class, or Objective-C
1896  /// class), will be set to the declaration.
1897  bool isIncompleteType(NamedDecl **Def = nullptr) const;
1898 
1899  /// Return true if this is an incomplete or object
1900  /// type, in other words, not a function type.
1902  return !isFunctionType();
1903  }
1904 
1905  /// Determine whether this type is an object type.
1906  bool isObjectType() const {
1907  // C++ [basic.types]p8:
1908  // An object type is a (possibly cv-qualified) type that is not a
1909  // function type, not a reference type, and not a void type.
1910  return !isReferenceType() && !isFunctionType() && !isVoidType();
1911  }
1912 
1913  /// Return true if this is a literal type
1914  /// (C++11 [basic.types]p10)
1915  bool isLiteralType(const ASTContext &Ctx) const;
1916 
1917  /// Test if this type is a standard-layout type.
1918  /// (C++0x [basic.type]p9)
1919  bool isStandardLayoutType() const;
1920 
1921  /// Helper methods to distinguish type categories. All type predicates
1922  /// operate on the canonical type, ignoring typedefs and qualifiers.
1923 
1924  /// Returns true if the type is a builtin type.
1925  bool isBuiltinType() const;
1926 
1927  /// Test for a particular builtin type.
1928  bool isSpecificBuiltinType(unsigned K) const;
1929 
1930  /// Test for a type which does not represent an actual type-system type but
1931  /// is instead used as a placeholder for various convenient purposes within
1932  /// Clang. All such types are BuiltinTypes.
1933  bool isPlaceholderType() const;
1934  const BuiltinType *getAsPlaceholderType() const;
1935 
1936  /// Test for a specific placeholder type.
1937  bool isSpecificPlaceholderType(unsigned K) const;
1938 
1939  /// Test for a placeholder type other than Overload; see
1940  /// BuiltinType::isNonOverloadPlaceholderType.
1941  bool isNonOverloadPlaceholderType() const;
1942 
1943  /// isIntegerType() does *not* include complex integers (a GCC extension).
1944  /// isComplexIntegerType() can be used to test for complex integers.
1945  bool isIntegerType() const; // C99 6.2.5p17 (int, char, bool, enum)
1946  bool isEnumeralType() const;
1947 
1948  /// Determine whether this type is a scoped enumeration type.
1949  bool isScopedEnumeralType() const;
1950  bool isBooleanType() const;
1951  bool isCharType() const;
1952  bool isWideCharType() const;
1953  bool isChar8Type() const;
1954  bool isChar16Type() const;
1955  bool isChar32Type() const;
1956  bool isAnyCharacterType() const;
1957  bool isIntegralType(const ASTContext &Ctx) const;
1958 
1959  /// Determine whether this type is an integral or enumeration type.
1960  bool isIntegralOrEnumerationType() const;
1961 
1962  /// Determine whether this type is an integral or unscoped enumeration type.
1963  bool isIntegralOrUnscopedEnumerationType() const;
1964 
1965  /// Floating point categories.
1966  bool isRealFloatingType() const; // C99 6.2.5p10 (float, double, long double)
1967  /// isComplexType() does *not* include complex integers (a GCC extension).
1968  /// isComplexIntegerType() can be used to test for complex integers.
1969  bool isComplexType() const; // C99 6.2.5p11 (complex)
1970  bool isAnyComplexType() const; // C99 6.2.5p11 (complex) + Complex Int.
1971  bool isFloatingType() const; // C99 6.2.5p11 (real floating + complex)
1972  bool isHalfType() const; // OpenCL 6.1.1.1, NEON (IEEE 754-2008 half)
1973  bool isFloat16Type() const; // C11 extension ISO/IEC TS 18661
1974  bool isFloat128Type() const;
1975  bool isRealType() const; // C99 6.2.5p17 (real floating + integer)
1976  bool isArithmeticType() const; // C99 6.2.5p18 (integer + floating)
1977  bool isVoidType() const; // C99 6.2.5p19
1978  bool isScalarType() const; // C99 6.2.5p21 (arithmetic + pointers)
1979  bool isAggregateType() const;
1980  bool isFundamentalType() const;
1981  bool isCompoundType() const;
1982 
1983  // Type Predicates: Check to see if this type is structurally the specified
1984  // type, ignoring typedefs and qualifiers.
1985  bool isFunctionType() const;
1986  bool isFunctionNoProtoType() const { return getAs<FunctionNoProtoType>(); }
1987  bool isFunctionProtoType() const { return getAs<FunctionProtoType>(); }
1988  bool isPointerType() const;
1989  bool isAnyPointerType() const; // Any C pointer or ObjC object pointer
1990  bool isBlockPointerType() const;
1991  bool isVoidPointerType() const;
1992  bool isReferenceType() const;
1993  bool isLValueReferenceType() const;
1994  bool isRValueReferenceType() const;
1995  bool isFunctionPointerType() const;
1996  bool isFunctionReferenceType() const;
1997  bool isMemberPointerType() const;
1998  bool isMemberFunctionPointerType() const;
1999  bool isMemberDataPointerType() const;
2000  bool isArrayType() const;
2001  bool isConstantArrayType() const;
2002  bool isIncompleteArrayType() const;
2003  bool isVariableArrayType() const;
2004  bool isDependentSizedArrayType() const;
2005  bool isRecordType() const;
2006  bool isClassType() const;
2007  bool isStructureType() const;
2008  bool isObjCBoxableRecordType() const;
2009  bool isInterfaceType() const;
2010  bool isStructureOrClassType() const;
2011  bool isUnionType() const;
2012  bool isComplexIntegerType() const; // GCC _Complex integer type.
2013  bool isVectorType() const; // GCC vector type.
2014  bool isExtVectorType() const; // Extended vector type.
2015  bool isDependentAddressSpaceType() const; // value-dependent address space qualifier
2016  bool isObjCObjectPointerType() const; // pointer to ObjC object
2017  bool isObjCRetainableType() const; // ObjC object or block pointer
2018  bool isObjCLifetimeType() const; // (array of)* retainable type
2019  bool isObjCIndirectLifetimeType() const; // (pointer to)* lifetime type
2020  bool isObjCNSObjectType() const; // __attribute__((NSObject))
2021  bool isObjCIndependentClassType() const; // __attribute__((objc_independent_class))
2022  // FIXME: change this to 'raw' interface type, so we can used 'interface' type
2023  // for the common case.
2024  bool isObjCObjectType() const; // NSString or typeof(*(id)0)
2025  bool isObjCQualifiedInterfaceType() const; // NSString<foo>
2026  bool isObjCQualifiedIdType() const; // id<foo>
2027  bool isObjCQualifiedClassType() const; // Class<foo>
2028  bool isObjCObjectOrInterfaceType() const;
2029  bool isObjCIdType() const; // id
2030  bool isDecltypeType() const;
2031  /// Was this type written with the special inert-in-ARC __unsafe_unretained
2032  /// qualifier?
2033  ///
2034  /// This approximates the answer to the following question: if this
2035  /// translation unit were compiled in ARC, would this type be qualified
2036  /// with __unsafe_unretained?
2038  return hasAttr(attr::ObjCInertUnsafeUnretained);
2039  }
2040 
2041  /// Whether the type is Objective-C 'id' or a __kindof type of an
2042  /// object type, e.g., __kindof NSView * or __kindof id
2043  /// <NSCopying>.
2044  ///
2045  /// \param bound Will be set to the bound on non-id subtype types,
2046  /// which will be (possibly specialized) Objective-C class type, or
2047  /// null for 'id.
2048  bool isObjCIdOrObjectKindOfType(const ASTContext &ctx,
2049  const ObjCObjectType *&bound) const;
2050 
2051  bool isObjCClassType() const; // Class
2052 
2053  /// Whether the type is Objective-C 'Class' or a __kindof type of an
2054  /// Class type, e.g., __kindof Class <NSCopying>.
2055  ///
2056  /// Unlike \c isObjCIdOrObjectKindOfType, there is no relevant bound
2057  /// here because Objective-C's type system cannot express "a class
2058  /// object for a subclass of NSFoo".
2059  bool isObjCClassOrClassKindOfType() const;
2060 
2061  bool isBlockCompatibleObjCPointerType(ASTContext &ctx) const;
2062  bool isObjCSelType() const; // Class
2063  bool isObjCBuiltinType() const; // 'id' or 'Class'
2064  bool isObjCARCBridgableType() const;
2065  bool isCARCBridgableType() const;
2066  bool isTemplateTypeParmType() const; // C++ template type parameter
2067  bool isNullPtrType() const; // C++11 std::nullptr_t
2068  bool isNothrowT() const; // C++ std::nothrow_t
2069  bool isAlignValT() const; // C++17 std::align_val_t
2070  bool isStdByteType() const; // C++17 std::byte
2071  bool isAtomicType() const; // C11 _Atomic()
2072 
2073 #define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
2074  bool is##Id##Type() const;
2075 #include "clang/Basic/OpenCLImageTypes.def"
2076 
2077  bool isImageType() const; // Any OpenCL image type
2078 
2079  bool isSamplerT() const; // OpenCL sampler_t
2080  bool isEventT() const; // OpenCL event_t
2081  bool isClkEventT() const; // OpenCL clk_event_t
2082  bool isQueueT() const; // OpenCL queue_t
2083  bool isReserveIDT() const; // OpenCL reserve_id_t
2084 
2085 #define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
2086  bool is##Id##Type() const;
2087 #include "clang/Basic/OpenCLExtensionTypes.def"
2088  // Type defined in cl_intel_device_side_avc_motion_estimation OpenCL extension
2089  bool isOCLIntelSubgroupAVCType() const;
2090  bool isOCLExtOpaqueType() const; // Any OpenCL extension type
2091 
2092  bool isPipeType() const; // OpenCL pipe type
2093  bool isOpenCLSpecificType() const; // Any OpenCL specific type
2094 
2095  /// Determines if this type, which must satisfy
2096  /// isObjCLifetimeType(), is implicitly __unsafe_unretained rather
2097  /// than implicitly __strong.
2098  bool isObjCARCImplicitlyUnretainedType() const;
2099 
2100  /// Return the implicit lifetime for this type, which must not be dependent.
2101  Qualifiers::ObjCLifetime getObjCARCImplicitLifetime() const;
2102 
2113  STK_FixedPoint
2114  };
2115 
2116  /// Given that this is a scalar type, classify it.
2117  ScalarTypeKind getScalarTypeKind() const;
2118 
2119  /// Whether this type is a dependent type, meaning that its definition
2120  /// somehow depends on a template parameter (C++ [temp.dep.type]).
2121  bool isDependentType() const { return TypeBits.Dependent; }
2122 
2123  /// Determine whether this type is an instantiation-dependent type,
2124  /// meaning that the type involves a template parameter (even if the
2125  /// definition does not actually depend on the type substituted for that
2126  /// template parameter).
2128  return TypeBits.InstantiationDependent;
2129  }
2130 
2131  /// Determine whether this type is an undeduced type, meaning that
2132  /// it somehow involves a C++11 'auto' type or similar which has not yet been
2133  /// deduced.
2134  bool isUndeducedType() const;
2135 
2136  /// Whether this type is a variably-modified type (C99 6.7.5).
2137  bool isVariablyModifiedType() const { return TypeBits.VariablyModified; }
2138 
2139  /// Whether this type involves a variable-length array type
2140  /// with a definite size.
2141  bool hasSizedVLAType() const;
2142 
2143  /// Whether this type is or contains a local or unnamed type.
2144  bool hasUnnamedOrLocalType() const;
2145 
2146  bool isOverloadableType() const;
2147 
2148  /// Determine wither this type is a C++ elaborated-type-specifier.
2149  bool isElaboratedTypeSpecifier() const;
2150 
2151  bool canDecayToPointerType() const;
2152 
2153  /// Whether this type is represented natively as a pointer. This includes
2154  /// pointers, references, block pointers, and Objective-C interface,
2155  /// qualified id, and qualified interface types, as well as nullptr_t.
2156  bool hasPointerRepresentation() const;
2157 
2158  /// Whether this type can represent an objective pointer type for the
2159  /// purpose of GC'ability
2160  bool hasObjCPointerRepresentation() const;
2161 
2162  /// Determine whether this type has an integer representation
2163  /// of some sort, e.g., it is an integer type or a vector.
2164  bool hasIntegerRepresentation() const;
2165 
2166  /// Determine whether this type has an signed integer representation
2167  /// of some sort, e.g., it is an signed integer type or a vector.
2168  bool hasSignedIntegerRepresentation() const;
2169 
2170  /// Determine whether this type has an unsigned integer representation
2171  /// of some sort, e.g., it is an unsigned integer type or a vector.
2172  bool hasUnsignedIntegerRepresentation() const;
2173 
2174  /// Determine whether this type has a floating-point representation
2175  /// of some sort, e.g., it is a floating-point type or a vector thereof.
2176  bool hasFloatingRepresentation() const;
2177 
2178  // Type Checking Functions: Check to see if this type is structurally the
2179  // specified type, ignoring typedefs and qualifiers, and return a pointer to
2180  // the best type we can.
2181  const RecordType *getAsStructureType() const;
2182  /// NOTE: getAs*ArrayType are methods on ASTContext.
2183  const RecordType *getAsUnionType() const;
2184  const ComplexType *getAsComplexIntegerType() const; // GCC complex int type.
2185  const ObjCObjectType *getAsObjCInterfaceType() const;
2186 
2187  // The following is a convenience method that returns an ObjCObjectPointerType
2188  // for object declared using an interface.
2189  const ObjCObjectPointerType *getAsObjCInterfacePointerType() const;
2190  const ObjCObjectPointerType *getAsObjCQualifiedIdType() const;
2191  const ObjCObjectPointerType *getAsObjCQualifiedClassType() const;
2192  const ObjCObjectType *getAsObjCQualifiedInterfaceType() const;
2193 
2194  /// Retrieves the CXXRecordDecl that this type refers to, either
2195  /// because the type is a RecordType or because it is the injected-class-name
2196  /// type of a class template or class template partial specialization.
2197  CXXRecordDecl *getAsCXXRecordDecl() const;
2198 
2199  /// Retrieves the RecordDecl this type refers to.
2200  RecordDecl *getAsRecordDecl() const;
2201 
2202  /// Retrieves the TagDecl that this type refers to, either
2203  /// because the type is a TagType or because it is the injected-class-name
2204  /// type of a class template or class template partial specialization.
2205  TagDecl *getAsTagDecl() const;
2206 
2207  /// If this is a pointer or reference to a RecordType, return the
2208  /// CXXRecordDecl that the type refers to.
2209  ///
2210  /// If this is not a pointer or reference, or the type being pointed to does
2211  /// not refer to a CXXRecordDecl, returns NULL.
2212  const CXXRecordDecl *getPointeeCXXRecordDecl() const;
2213 
2214  /// Get the DeducedType whose type will be deduced for a variable with
2215  /// an initializer of this type. This looks through declarators like pointer
2216  /// types, but not through decltype or typedefs.
2217  DeducedType *getContainedDeducedType() const;
2218 
2219  /// Get the AutoType whose type will be deduced for a variable with
2220  /// an initializer of this type. This looks through declarators like pointer
2221  /// types, but not through decltype or typedefs.
2223  return dyn_cast_or_null<AutoType>(getContainedDeducedType());
2224  }
2225 
2226  /// Determine whether this type was written with a leading 'auto'
2227  /// corresponding to a trailing return type (possibly for a nested
2228  /// function type within a pointer to function type or similar).
2229  bool hasAutoForTrailingReturnType() const;
2230 
2231  /// Member-template getAs<specific type>'. Look through sugar for
2232  /// an instance of <specific type>. This scheme will eventually
2233  /// replace the specific getAsXXXX methods above.
2234  ///
2235  /// There are some specializations of this member template listed
2236  /// immediately following this class.
2237  template <typename T> const T *getAs() const;
2238 
2239  /// Member-template getAsAdjusted<specific type>. Look through specific kinds
2240  /// of sugar (parens, attributes, etc) for an instance of <specific type>.
2241  /// This is used when you need to walk over sugar nodes that represent some
2242  /// kind of type adjustment from a type that was written as a <specific type>
2243  /// to another type that is still canonically a <specific type>.
2244  template <typename T> const T *getAsAdjusted() const;
2245 
2246  /// A variant of getAs<> for array types which silently discards
2247  /// qualifiers from the outermost type.
2248  const ArrayType *getAsArrayTypeUnsafe() const;
2249 
2250  /// Member-template castAs<specific type>. Look through sugar for
2251  /// the underlying instance of <specific type>.
2252  ///
2253  /// This method has the same relationship to getAs<T> as cast<T> has
2254  /// to dyn_cast<T>; which is to say, the underlying type *must*
2255  /// have the intended type, and this method will never return null.
2256  template <typename T> const T *castAs() const;
2257 
2258  /// A variant of castAs<> for array type which silently discards
2259  /// qualifiers from the outermost type.
2260  const ArrayType *castAsArrayTypeUnsafe() const;
2261 
2262  /// Determine whether this type had the specified attribute applied to it
2263  /// (looking through top-level type sugar).
2264  bool hasAttr(attr::Kind AK) const;
2265 
2266  /// Get the base element type of this type, potentially discarding type
2267  /// qualifiers. This should never be used when type qualifiers
2268  /// are meaningful.
2269  const Type *getBaseElementTypeUnsafe() const;
2270 
2271  /// If this is an array type, return the element type of the array,
2272  /// potentially with type qualifiers missing.
2273  /// This should never be used when type qualifiers are meaningful.
2274  const Type *getArrayElementTypeNoTypeQual() const;
2275 
2276  /// If this is a pointer type, return the pointee type.
2277  /// If this is an array type, return the array element type.
2278  /// This should never be used when type qualifiers are meaningful.
2279  const Type *getPointeeOrArrayElementType() const;
2280 
2281  /// If this is a pointer, ObjC object pointer, or block
2282  /// pointer, this returns the respective pointee.
2283  QualType getPointeeType() const;
2284 
2285  /// Return the specified type with any "sugar" removed from the type,
2286  /// removing any typedefs, typeofs, etc., as well as any qualifiers.
2287  const Type *getUnqualifiedDesugaredType() const;
2288 
2289  /// More type predicates useful for type checking/promotion
2290  bool isPromotableIntegerType() const; // C99 6.3.1.1p2
2291 
2292  /// Return true if this is an integer type that is
2293  /// signed, according to C99 6.2.5p4 [char, signed char, short, int, long..],
2294  /// or an enum decl which has a signed representation.
2295  bool isSignedIntegerType() const;
2296 
2297  /// Return true if this is an integer type that is
2298  /// unsigned, according to C99 6.2.5p6 [which returns true for _Bool],
2299  /// or an enum decl which has an unsigned representation.
2300  bool isUnsignedIntegerType() const;
2301 
2302  /// Determines whether this is an integer type that is signed or an
2303  /// enumeration types whose underlying type is a signed integer type.
2304  bool isSignedIntegerOrEnumerationType() const;
2305 
2306  /// Determines whether this is an integer type that is unsigned or an
2307  /// enumeration types whose underlying type is a unsigned integer type.
2308  bool isUnsignedIntegerOrEnumerationType() const;
2309 
2310  /// Return true if this is a fixed point type according to
2311  /// ISO/IEC JTC1 SC22 WG14 N1169.
2312  bool isFixedPointType() const;
2313 
2314  /// Return true if this is a fixed point or integer type.
2315  bool isFixedPointOrIntegerType() const;
2316 
2317  /// Return true if this is a saturated fixed point type according to
2318  /// ISO/IEC JTC1 SC22 WG14 N1169. This type can be signed or unsigned.
2319  bool isSaturatedFixedPointType() const;
2320 
2321  /// Return true if this is a saturated fixed point type according to
2322  /// ISO/IEC JTC1 SC22 WG14 N1169. This type can be signed or unsigned.
2323  bool isUnsaturatedFixedPointType() const;
2324 
2325  /// Return true if this is a fixed point type that is signed according
2326  /// to ISO/IEC JTC1 SC22 WG14 N1169. This type can also be saturated.
2327  bool isSignedFixedPointType() const;
2328 
2329  /// Return true if this is a fixed point type that is unsigned according
2330  /// to ISO/IEC JTC1 SC22 WG14 N1169. This type can also be saturated.
2331  bool isUnsignedFixedPointType() const;
2332 
2333  /// Return true if this is not a variable sized type,
2334  /// according to the rules of C99 6.7.5p3. It is not legal to call this on
2335  /// incomplete types.
2336  bool isConstantSizeType() const;
2337 
2338  /// Returns true if this type can be represented by some
2339  /// set of type specifiers.
2340  bool isSpecifierType() const;
2341 
2342  /// Determine the linkage of this type.
2343  Linkage getLinkage() const;
2344 
2345  /// Determine the visibility of this type.
2347  return getLinkageAndVisibility().getVisibility();
2348  }
2349 
2350  /// Return true if the visibility was explicitly set is the code.
2351  bool isVisibilityExplicit() const {
2352  return getLinkageAndVisibility().isVisibilityExplicit();
2353  }
2354 
2355  /// Determine the linkage and visibility of this type.
2356  LinkageInfo getLinkageAndVisibility() const;
2357 
2358  /// True if the computed linkage is valid. Used for consistency
2359  /// checking. Should always return true.
2360  bool isLinkageValid() const;
2361 
2362  /// Determine the nullability of the given type.
2363  ///
2364  /// Note that nullability is only captured as sugar within the type
2365  /// system, not as part of the canonical type, so nullability will
2366  /// be lost by canonicalization and desugaring.
2367  Optional<NullabilityKind> getNullability(const ASTContext &context) const;
2368 
2369  /// Determine whether the given type can have a nullability
2370  /// specifier applied to it, i.e., if it is any kind of pointer type.
2371  ///
2372  /// \param ResultIfUnknown The value to return if we don't yet know whether
2373  /// this type can have nullability because it is dependent.
2374  bool canHaveNullability(bool ResultIfUnknown = true) const;
2375 
2376  /// Retrieve the set of substitutions required when accessing a member
2377  /// of the Objective-C receiver type that is declared in the given context.
2378  ///
2379  /// \c *this is the type of the object we're operating on, e.g., the
2380  /// receiver for a message send or the base of a property access, and is
2381  /// expected to be of some object or object pointer type.
2382  ///
2383  /// \param dc The declaration context for which we are building up a
2384  /// substitution mapping, which should be an Objective-C class, extension,
2385  /// category, or method within.
2386  ///
2387  /// \returns an array of type arguments that can be substituted for
2388  /// the type parameters of the given declaration context in any type described
2389  /// within that context, or an empty optional to indicate that no
2390  /// substitution is required.
2392  getObjCSubstitutions(const DeclContext *dc) const;
2393 
2394  /// Determines if this is an ObjC interface type that may accept type
2395  /// parameters.
2396  bool acceptsObjCTypeParams() const;
2397 
2398  const char *getTypeClassName() const;
2399 
2401  return CanonicalType;
2402  }
2403 
2404  CanQualType getCanonicalTypeUnqualified() const; // in CanonicalType.h
2405  void dump() const;
2406  void dump(llvm::raw_ostream &OS) const;
2407 };
2408 
2409 /// This will check for a TypedefType by removing any existing sugar
2410 /// until it reaches a TypedefType or a non-sugared type.
2411 template <> const TypedefType *Type::getAs() const;
2412 
2413 /// This will check for a TemplateSpecializationType by removing any
2414 /// existing sugar until it reaches a TemplateSpecializationType or a
2415 /// non-sugared type.
2416 template <> const TemplateSpecializationType *Type::getAs() const;
2417 
2418 /// This will check for an AttributedType by removing any existing sugar
2419 /// until it reaches an AttributedType or a non-sugared type.
2420 template <> const AttributedType *Type::getAs() const;
2421 
2422 // We can do canonical leaf types faster, because we don't have to
2423 // worry about preserving child type decoration.
2424 #define TYPE(Class, Base)
2425 #define LEAF_TYPE(Class) \
2426 template <> inline const Class##Type *Type::getAs() const { \
2427  return dyn_cast<Class##Type>(CanonicalType); \
2428 } \
2429 template <> inline const Class##Type *Type::castAs() const { \
2430  return cast<Class##Type>(CanonicalType); \
2431 }
2432 #include "clang/AST/TypeNodes.inc"
2433 
2434 /// This class is used for builtin types like 'int'. Builtin
2435 /// types are always canonical and have a literal name field.
2436 class BuiltinType : public Type {
2437 public:
2438  enum Kind {
2439 // OpenCL image types
2440 #define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) Id,
2441 #include "clang/Basic/OpenCLImageTypes.def"
2442 // OpenCL extension types
2443 #define EXT_OPAQUE_TYPE(ExtType, Id, Ext) Id,
2444 #include "clang/Basic/OpenCLExtensionTypes.def"
2445 // SVE Types
2446 #define SVE_TYPE(Name, Id, SingletonId) Id,
2447 #include "clang/Basic/AArch64SVEACLETypes.def"
2448 // All other builtin types
2449 #define BUILTIN_TYPE(Id, SingletonId) Id,
2450 #define LAST_BUILTIN_TYPE(Id) LastKind = Id
2451 #include "clang/AST/BuiltinTypes.def"
2452  };
2453 
2454 private:
2455  friend class ASTContext; // ASTContext creates these.
2456 
2457  BuiltinType(Kind K)
2458  : Type(Builtin, QualType(), /*Dependent=*/(K == Dependent),
2459  /*InstantiationDependent=*/(K == Dependent),
2460  /*VariablyModified=*/false,
2461  /*Unexpanded parameter pack=*/false) {
2462  BuiltinTypeBits.Kind = K;
2463  }
2464 
2465 public:
2466  Kind getKind() const { return static_cast<Kind>(BuiltinTypeBits.Kind); }
2467  StringRef getName(const PrintingPolicy &Policy) const;
2468 
2469  const char *getNameAsCString(const PrintingPolicy &Policy) const {
2470  // The StringRef is null-terminated.
2471  StringRef str = getName(Policy);
2472  assert(!str.empty() && str.data()[str.size()] == '\0');
2473  return str.data();
2474  }
2475 
2476  bool isSugared() const { return false; }
2477  QualType desugar() const { return QualType(this, 0); }
2478 
2479  bool isInteger() const {
2480  return getKind() >= Bool && getKind() <= Int128;
2481  }
2482 
2483  bool isSignedInteger() const {
2484  return getKind() >= Char_S && getKind() <= Int128;
2485  }
2486 
2487  bool isUnsignedInteger() const {
2488  return getKind() >= Bool && getKind() <= UInt128;
2489  }
2490 
2491  bool isFloatingPoint() const {
2492  return getKind() >= Half && getKind() <= Float128;
2493  }
2494 
2495  /// Determines whether the given kind corresponds to a placeholder type.
2496  static bool isPlaceholderTypeKind(Kind K) {
2497  return K >= Overload;
2498  }
2499 
2500  /// Determines whether this type is a placeholder type, i.e. a type
2501  /// which cannot appear in arbitrary positions in a fully-formed
2502  /// expression.
2503  bool isPlaceholderType() const {
2504  return isPlaceholderTypeKind(getKind());
2505  }
2506 
2507  /// Determines whether this type is a placeholder type other than
2508  /// Overload. Most placeholder types require only syntactic
2509  /// information about their context in order to be resolved (e.g.
2510  /// whether it is a call expression), which means they can (and
2511  /// should) be resolved in an earlier "phase" of analysis.
2512  /// Overload expressions sometimes pick up further information
2513  /// from their context, like whether the context expects a
2514  /// specific function-pointer type, and so frequently need
2515  /// special treatment.
2517  return getKind() > Overload;
2518  }
2519 
2520  static bool classof(const Type *T) { return T->getTypeClass() == Builtin; }
2521 };
2522 
2523 /// Complex values, per C99 6.2.5p11. This supports the C99 complex
2524 /// types (_Complex float etc) as well as the GCC integer complex extensions.
2525 class ComplexType : public Type, public llvm::FoldingSetNode {
2526  friend class ASTContext; // ASTContext creates these.
2527 
2528  QualType ElementType;
2529 
2530  ComplexType(QualType Element, QualType CanonicalPtr)
2531  : Type(Complex, CanonicalPtr, Element->isDependentType(),
2532  Element->isInstantiationDependentType(),
2533  Element->isVariablyModifiedType(),
2534  Element->containsUnexpandedParameterPack()),
2535  ElementType(Element) {}
2536 
2537 public:
2538  QualType getElementType() const { return ElementType; }
2539 
2540  bool isSugared() const { return false; }
2541  QualType desugar() const { return QualType(this, 0); }
2542 
2543  void Profile(llvm::FoldingSetNodeID &ID) {
2544  Profile(ID, getElementType());
2545  }
2546 
2547  static void Profile(llvm::FoldingSetNodeID &ID, QualType Element) {
2548  ID.AddPointer(Element.getAsOpaquePtr());
2549  }
2550 
2551  static bool classof(const Type *T) { return T->getTypeClass() == Complex; }
2552 };
2553 
2554 /// Sugar for parentheses used when specifying types.
2555 class ParenType : public Type, public llvm::FoldingSetNode {
2556  friend class ASTContext; // ASTContext creates these.
2557 
2558  QualType Inner;
2559 
2560  ParenType(QualType InnerType, QualType CanonType)
2561  : Type(Paren, CanonType, InnerType->isDependentType(),
2562  InnerType->isInstantiationDependentType(),
2563  InnerType->isVariablyModifiedType(),
2564  InnerType->containsUnexpandedParameterPack()),
2565  Inner(InnerType) {}
2566 
2567 public:
2568  QualType getInnerType() const { return Inner; }
2569 
2570  bool isSugared() const { return true; }
2571  QualType desugar() const { return getInnerType(); }
2572 
2573  void Profile(llvm::FoldingSetNodeID &ID) {
2574  Profile(ID, getInnerType());
2575  }
2576 
2577  static void Profile(llvm::FoldingSetNodeID &ID, QualType Inner) {
2578  Inner.Profile(ID);
2579  }
2580 
2581  static bool classof(const Type *T) { return T->getTypeClass() == Paren; }
2582 };
2583 
2584 /// PointerType - C99 6.7.5.1 - Pointer Declarators.
2585 class PointerType : public Type, public llvm::FoldingSetNode {
2586  friend class ASTContext; // ASTContext creates these.
2587 
2588  QualType PointeeType;
2589 
2590  PointerType(QualType Pointee, QualType CanonicalPtr)
2591  : Type(Pointer, CanonicalPtr, Pointee->isDependentType(),
2592  Pointee->isInstantiationDependentType(),
2593  Pointee->isVariablyModifiedType(),
2594  Pointee->containsUnexpandedParameterPack()),
2595  PointeeType(Pointee) {}
2596 
2597 public:
2598  QualType getPointeeType() const { return PointeeType; }
2599 
2600  /// Returns true if address spaces of pointers overlap.
2601  /// OpenCL v2.0 defines conversion rules for pointers to different
2602  /// address spaces (OpenCLC v2.0 s6.5.5) and notion of overlapping
2603  /// address spaces.
2604  /// CL1.1 or CL1.2:
2605  /// address spaces overlap iff they are they same.
2606  /// CL2.0 adds:
2607  /// __generic overlaps with any address space except for __constant.
2608  bool isAddressSpaceOverlapping(const PointerType &other) const {
2609  Qualifiers thisQuals = PointeeType.getQualifiers();
2610  Qualifiers otherQuals = other.getPointeeType().getQualifiers();
2611  // Address spaces overlap if at least one of them is a superset of another
2612  return thisQuals.isAddressSpaceSupersetOf(otherQuals) ||
2613  otherQuals.isAddressSpaceSupersetOf(thisQuals);
2614  }
2615 
2616  bool isSugared() const { return false; }
2617  QualType desugar() const { return QualType(this, 0); }
2618 
2619  void Profile(llvm::FoldingSetNodeID &ID) {
2620  Profile(ID, getPointeeType());
2621  }
2622 
2623  static void Profile(llvm::FoldingSetNodeID &ID, QualType Pointee) {
2624  ID.AddPointer(Pointee.getAsOpaquePtr());
2625  }
2626 
2627  static bool classof(const Type *T) { return T->getTypeClass() == Pointer; }
2628 };
2629 
2630 /// Represents a type which was implicitly adjusted by the semantic
2631 /// engine for arbitrary reasons. For example, array and function types can
2632 /// decay, and function types can have their calling conventions adjusted.
2633 class AdjustedType : public Type, public llvm::FoldingSetNode {
2634  QualType OriginalTy;
2635  QualType AdjustedTy;
2636 
2637 protected:
2638  friend class ASTContext; // ASTContext creates these.
2639 
2640  AdjustedType(TypeClass TC, QualType OriginalTy, QualType AdjustedTy,
2641  QualType CanonicalPtr)
2642  : Type(TC, CanonicalPtr, OriginalTy->isDependentType(),
2643  OriginalTy->isInstantiationDependentType(),
2644  OriginalTy->isVariablyModifiedType(),
2645  OriginalTy->containsUnexpandedParameterPack()),
2646  OriginalTy(OriginalTy), AdjustedTy(AdjustedTy) {}
2647 
2648 public:
2649  QualType getOriginalType() const { return OriginalTy; }
2650  QualType getAdjustedType() const { return AdjustedTy; }
2651 
2652  bool isSugared() const { return true; }
2653  QualType desugar() const { return AdjustedTy; }
2654 
2655  void Profile(llvm::FoldingSetNodeID &ID) {
2656  Profile(ID, OriginalTy, AdjustedTy);
2657  }
2658 
2659  static void Profile(llvm::FoldingSetNodeID &ID, QualType Orig, QualType New) {
2660  ID.AddPointer(Orig.getAsOpaquePtr());
2661  ID.AddPointer(New.getAsOpaquePtr());
2662  }
2663 
2664  static bool classof(const Type *T) {
2665  return T->getTypeClass() == Adjusted || T->getTypeClass() == Decayed;
2666  }
2667 };
2668 
2669 /// Represents a pointer type decayed from an array or function type.
2670 class DecayedType : public AdjustedType {
2671  friend class ASTContext; // ASTContext creates these.
2672 
2673  inline
2674  DecayedType(QualType OriginalType, QualType Decayed, QualType Canonical);
2675 
2676 public:
2677  QualType getDecayedType() const { return getAdjustedType(); }
2678 
2679  inline QualType getPointeeType() const;
2680 
2681  static bool classof(const Type *T) { return T->getTypeClass() == Decayed; }
2682 };
2683 
2684 /// Pointer to a block type.
2685 /// This type is to represent types syntactically represented as
2686 /// "void (^)(int)", etc. Pointee is required to always be a function type.
2687 class BlockPointerType : public Type, public llvm::FoldingSetNode {
2688  friend class ASTContext; // ASTContext creates these.
2689 
2690  // Block is some kind of pointer type
2691  QualType PointeeType;
2692 
2693  BlockPointerType(QualType Pointee, QualType CanonicalCls)
2694  : Type(BlockPointer, CanonicalCls, Pointee->isDependentType(),
2695  Pointee->isInstantiationDependentType(),
2696  Pointee->isVariablyModifiedType(),
2697  Pointee->containsUnexpandedParameterPack()),
2698  PointeeType(Pointee) {}
2699 
2700 public:
2701  // Get the pointee type. Pointee is required to always be a function type.
2702  QualType getPointeeType() const { return PointeeType; }
2703 
2704  bool isSugared() const { return false; }
2705  QualType desugar() const { return QualType(this, 0); }
2706 
2707  void Profile(llvm::FoldingSetNodeID &ID) {
2708  Profile(ID, getPointeeType());
2709  }
2710 
2711  static void Profile(llvm::FoldingSetNodeID &ID, QualType Pointee) {
2712  ID.AddPointer(Pointee.getAsOpaquePtr());
2713  }
2714 
2715  static bool classof(const Type *T) {
2716  return T->getTypeClass() == BlockPointer;
2717  }
2718 };
2719 
2720 /// Base for LValueReferenceType and RValueReferenceType
2721 class ReferenceType : public Type, public llvm::FoldingSetNode {
2722  QualType PointeeType;
2723 
2724 protected:
2725  ReferenceType(TypeClass tc, QualType Referencee, QualType CanonicalRef,
2726  bool SpelledAsLValue)
2727  : Type(tc, CanonicalRef, Referencee->isDependentType(),
2728  Referencee->isInstantiationDependentType(),
2729  Referencee->isVariablyModifiedType(),
2730  Referencee->containsUnexpandedParameterPack()),
2731  PointeeType(Referencee) {
2732  ReferenceTypeBits.SpelledAsLValue = SpelledAsLValue;
2733  ReferenceTypeBits.InnerRef = Referencee->isReferenceType();
2734  }
2735 
2736 public:
2737  bool isSpelledAsLValue() const { return ReferenceTypeBits.SpelledAsLValue; }
2738  bool isInnerRef() const { return ReferenceTypeBits.InnerRef; }
2739 
2740  QualType getPointeeTypeAsWritten() const { return PointeeType; }
2741 
2743  // FIXME: this might strip inner qualifiers; okay?
2744  const ReferenceType *T = this;
2745  while (T->isInnerRef())
2746  T = T->PointeeType->castAs<ReferenceType>();
2747  return T->PointeeType;
2748  }
2749 
2750  void Profile(llvm::FoldingSetNodeID &ID) {
2751  Profile(ID, PointeeType, isSpelledAsLValue());
2752  }
2753 
2754  static void Profile(llvm::FoldingSetNodeID &ID,
2755  QualType Referencee,
2756  bool SpelledAsLValue) {
2757  ID.AddPointer(Referencee.getAsOpaquePtr());
2758  ID.AddBoolean(SpelledAsLValue);
2759  }
2760 
2761  static bool classof(const Type *T) {
2762  return T->getTypeClass() == LValueReference ||
2763  T->getTypeClass() == RValueReference;
2764  }
2765 };
2766 
2767 /// An lvalue reference type, per C++11 [dcl.ref].
2769  friend class ASTContext; // ASTContext creates these
2770 
2771  LValueReferenceType(QualType Referencee, QualType CanonicalRef,
2772  bool SpelledAsLValue)
2773  : ReferenceType(LValueReference, Referencee, CanonicalRef,
2774  SpelledAsLValue) {}
2775 
2776 public:
2777  bool isSugared() const { return false; }
2778  QualType desugar() const { return QualType(this, 0); }
2779 
2780  static bool classof(const Type *T) {
2781  return T->getTypeClass() == LValueReference;
2782  }
2783 };
2784 
2785 /// An rvalue reference type, per C++11 [dcl.ref].
2787  friend class ASTContext; // ASTContext creates these
2788 
2789  RValueReferenceType(QualType Referencee, QualType CanonicalRef)
2790  : ReferenceType(RValueReference, Referencee, CanonicalRef, false) {}
2791 
2792 public:
2793  bool isSugared() const { return false; }
2794  QualType desugar() const { return QualType(this, 0); }
2795 
2796  static bool classof(const Type *T) {
2797  return T->getTypeClass() == RValueReference;
2798  }
2799 };
2800 
2801 /// A pointer to member type per C++ 8.3.3 - Pointers to members.
2802 ///
2803 /// This includes both pointers to data members and pointer to member functions.
2804 class MemberPointerType : public Type, public llvm::FoldingSetNode {
2805  friend class ASTContext; // ASTContext creates these.
2806 
2807  QualType PointeeType;
2808 
2809  /// The class of which the pointee is a member. Must ultimately be a
2810  /// RecordType, but could be a typedef or a template parameter too.
2811  const Type *Class;
2812 
2813  MemberPointerType(QualType Pointee, const Type *Cls, QualType CanonicalPtr)
2814  : Type(MemberPointer, CanonicalPtr,
2815  Cls->isDependentType() || Pointee->isDependentType(),
2816  (Cls->isInstantiationDependentType() ||
2817  Pointee->isInstantiationDependentType()),
2818  Pointee->isVariablyModifiedType(),
2819  (Cls->containsUnexpandedParameterPack() ||
2820  Pointee->containsUnexpandedParameterPack())),
2821  PointeeType(Pointee), Class(Cls) {}
2822 
2823 public:
2824  QualType getPointeeType() const { return PointeeType; }
2825 
2826  /// Returns true if the member type (i.e. the pointee type) is a
2827  /// function type rather than a data-member type.
2829  return PointeeType->isFunctionProtoType();
2830  }
2831 
2832  /// Returns true if the member type (i.e. the pointee type) is a
2833  /// data type rather than a function type.
2834  bool isMemberDataPointer() const {
2835  return !PointeeType->isFunctionProtoType();
2836  }
2837 
2838  const Type *getClass() const { return Class; }
2839  CXXRecordDecl *getMostRecentCXXRecordDecl() const;
2840 
2841  bool isSugared() const { return false; }
2842  QualType desugar() const { return QualType(this, 0); }
2843 
2844  void Profile(llvm::FoldingSetNodeID &ID) {
2845  Profile(ID, getPointeeType(), getClass());
2846  }
2847 
2848  static void Profile(llvm::FoldingSetNodeID &ID, QualType Pointee,
2849  const Type *Class) {
2850  ID.AddPointer(Pointee.getAsOpaquePtr());
2851  ID.AddPointer(Class);
2852  }
2853 
2854  static bool classof(const Type *T) {
2855  return T->getTypeClass() == MemberPointer;
2856  }
2857 };
2858 
2859 /// Represents an array type, per C99 6.7.5.2 - Array Declarators.
2860 class ArrayType : public Type, public llvm::FoldingSetNode {
2861 public:
2862  /// Capture whether this is a normal array (e.g. int X[4])
2863  /// an array with a static size (e.g. int X[static 4]), or an array
2864  /// with a star size (e.g. int X[*]).
2865  /// 'static' is only allowed on function parameters.
2868  };
2869 
2870 private:
2871  /// The element type of the array.
2872  QualType ElementType;
2873 
2874 protected:
2875  friend class ASTContext; // ASTContext creates these.
2876 
2878  unsigned tq, const Expr *sz = nullptr);
2879 
2880 public:
2881  QualType getElementType() const { return ElementType; }
2882 
2884  return ArraySizeModifier(ArrayTypeBits.SizeModifier);
2885  }
2886 
2888  return Qualifiers::fromCVRMask(getIndexTypeCVRQualifiers());
2889  }
2890 
2891  unsigned getIndexTypeCVRQualifiers() const {
2892  return ArrayTypeBits.IndexTypeQuals;
2893  }
2894 
2895  static bool classof(const Type *T) {
2896  return T->getTypeClass() == ConstantArray ||
2897  T->getTypeClass() == VariableArray ||
2898  T->getTypeClass() == IncompleteArray ||
2899  T->getTypeClass() == DependentSizedArray;
2900  }
2901 };
2902 
2903 /// Represents the canonical version of C arrays with a specified constant size.
2904 /// For example, the canonical type for 'int A[4 + 4*100]' is a
2905 /// ConstantArrayType where the element type is 'int' and the size is 404.
2907  : public ArrayType,
2908  private llvm::TrailingObjects<ConstantArrayType, const Expr *> {
2909  friend class ASTContext; // ASTContext creates these.
2910  friend TrailingObjects;
2911 
2912  llvm::APInt Size; // Allows us to unique the type.
2913 
2914  ConstantArrayType(QualType et, QualType can, const llvm::APInt &size,
2915  const Expr *sz, ArraySizeModifier sm, unsigned tq)
2916  : ArrayType(ConstantArray, et, can, sm, tq, sz), Size(size) {
2917  ConstantArrayTypeBits.HasStoredSizeExpr = sz != nullptr;
2918  if (ConstantArrayTypeBits.HasStoredSizeExpr) {
2919  assert(!can.isNull() && "canonical constant array should not have size");
2920  *getTrailingObjects<const Expr*>() = sz;
2921  }
2922  }
2923 
2924  unsigned numTrailingObjects(OverloadToken<const Expr*>) const {
2925  return ConstantArrayTypeBits.HasStoredSizeExpr;
2926  }
2927 
2928 public:
2929  const llvm::APInt &getSize() const { return Size; }
2930  const Expr *getSizeExpr() const {
2931  return ConstantArrayTypeBits.HasStoredSizeExpr
2932  ? *getTrailingObjects<const Expr *>()
2933  : nullptr;
2934  }
2935  bool isSugared() const { return false; }
2936  QualType desugar() const { return QualType(this, 0); }
2937 
2938  /// Determine the number of bits required to address a member of
2939  // an array with the given element type and number of elements.
2940  static unsigned getNumAddressingBits(const ASTContext &Context,
2941  QualType ElementType,
2942  const llvm::APInt &NumElements);
2943 
2944  /// Determine the maximum number of active bits that an array's size
2945  /// can require, which limits the maximum size of the array.
2946  static unsigned getMaxSizeBits(const ASTContext &Context);
2947 
2948  void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx) {
2949  Profile(ID, Ctx, getElementType(), getSize(), getSizeExpr(),
2950  getSizeModifier(), getIndexTypeCVRQualifiers());
2951  }
2952 
2953  static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx,
2954  QualType ET, const llvm::APInt &ArraySize,
2955  const Expr *SizeExpr, ArraySizeModifier SizeMod,
2956  unsigned TypeQuals);
2957 
2958  static bool classof(const Type *T) {
2959  return T->getTypeClass() == ConstantArray;
2960  }
2961 };
2962 
2963 /// Represents a C array with an unspecified size. For example 'int A[]' has
2964 /// an IncompleteArrayType where the element type is 'int' and the size is
2965 /// unspecified.
2967  friend class ASTContext; // ASTContext creates these.
2968 
2970  ArraySizeModifier sm, unsigned tq)
2971  : ArrayType(IncompleteArray, et, can, sm, tq) {}
2972 
2973 public:
2974  friend class StmtIteratorBase;
2975 
2976  bool isSugared() const { return false; }
2977  QualType desugar() const { return QualType(this, 0); }
2978 
2979  static bool classof(const Type *T) {
2980  return T->getTypeClass() == IncompleteArray;
2981  }
2982 
2983  void Profile(llvm::FoldingSetNodeID &ID) {
2984  Profile(ID, getElementType(), getSizeModifier(),
2985  getIndexTypeCVRQualifiers());
2986  }
2987 
2988  static void Profile(llvm::FoldingSetNodeID &ID, QualType ET,
2989  ArraySizeModifier SizeMod, unsigned TypeQuals) {
2990  ID.AddPointer(ET.getAsOpaquePtr());
2991  ID.AddInteger(SizeMod);
2992  ID.AddInteger(TypeQuals);
2993  }
2994 };
2995 
2996 /// Represents a C array with a specified size that is not an
2997 /// integer-constant-expression. For example, 'int s[x+foo()]'.
2998 /// Since the size expression is an arbitrary expression, we store it as such.
2999 ///
3000 /// Note: VariableArrayType's aren't uniqued (since the expressions aren't) and
3001 /// should not be: two lexically equivalent variable array types could mean
3002 /// different things, for example, these variables do not have the same type
3003 /// dynamically:
3004 ///
3005 /// void foo(int x) {
3006 /// int Y[x];
3007 /// ++x;
3008 /// int Z[x];
3009 /// }
3011  friend class ASTContext; // ASTContext creates these.
3012 
3013  /// An assignment-expression. VLA's are only permitted within
3014  /// a function block.
3015  Stmt *SizeExpr;
3016 
3017  /// The range spanned by the left and right array brackets.
3018  SourceRange Brackets;
3019 
3021  ArraySizeModifier sm, unsigned tq,
3022  SourceRange brackets)
3023  : ArrayType(VariableArray, et, can, sm, tq, e),
3024  SizeExpr((Stmt*) e), Brackets(brackets) {}
3025 
3026 public:
3027  friend class StmtIteratorBase;
3028 
3029  Expr *getSizeExpr() const {
3030  // We use C-style casts instead of cast<> here because we do not wish
3031  // to have a dependency of Type.h on Stmt.h/Expr.h.
3032  return (Expr*) SizeExpr;
3033  }
3034 
3035  SourceRange getBracketsRange() const { return Brackets; }
3036  SourceLocation getLBracketLoc() const { return Brackets.getBegin(); }
3037  SourceLocation getRBracketLoc() const { return Brackets.getEnd(); }
3038 
3039  bool isSugared() const { return false; }
3040  QualType desugar() const { return QualType(this, 0); }
3041 
3042  static bool classof(const Type *T) {
3043  return T->getTypeClass() == VariableArray;
3044  }
3045 
3046  void Profile(llvm::FoldingSetNodeID &ID) {
3047  llvm_unreachable("Cannot unique VariableArrayTypes.");
3048  }
3049 };
3050 
3051 /// Represents an array type in C++ whose size is a value-dependent expression.
3052 ///
3053 /// For example:
3054 /// \code
3055 /// template<typename T, int Size>
3056 /// class array {
3057 /// T data[Size];
3058 /// };
3059 /// \endcode
3060 ///
3061 /// For these types, we won't actually know what the array bound is
3062 /// until template instantiation occurs, at which point this will
3063 /// become either a ConstantArrayType or a VariableArrayType.
3065  friend class ASTContext; // ASTContext creates these.
3066 
3067  const ASTContext &Context;
3068 
3069  /// An assignment expression that will instantiate to the
3070  /// size of the array.
3071  ///
3072  /// The expression itself might be null, in which case the array
3073  /// type will have its size deduced from an initializer.
3074  Stmt *SizeExpr;
3075 
3076  /// The range spanned by the left and right array brackets.
3077  SourceRange Brackets;
3078 
3079  DependentSizedArrayType(const ASTContext &Context, QualType et, QualType can,
3080  Expr *e, ArraySizeModifier sm, unsigned tq,
3081  SourceRange brackets);
3082 
3083 public:
3084  friend class StmtIteratorBase;
3085 
3086  Expr *getSizeExpr() const {
3087  // We use C-style casts instead of cast<> here because we do not wish
3088  // to have a dependency of Type.h on Stmt.h/Expr.h.
3089  return (Expr*) SizeExpr;
3090  }
3091 
3092  SourceRange getBracketsRange() const { return Brackets; }
3093  SourceLocation getLBracketLoc() const { return Brackets.getBegin(); }
3094  SourceLocation getRBracketLoc() const { return Brackets.getEnd(); }
3095 
3096  bool isSugared() const { return false; }
3097  QualType desugar() const { return QualType(this, 0); }
3098 
3099  static bool classof(const Type *T) {
3100  return T->getTypeClass() == DependentSizedArray;
3101  }
3102 
3103  void Profile(llvm::FoldingSetNodeID &ID) {
3104  Profile(ID, Context, getElementType(),
3105  getSizeModifier(), getIndexTypeCVRQualifiers(), getSizeExpr());
3106  }
3107 
3108  static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
3109  QualType ET, ArraySizeModifier SizeMod,
3110  unsigned TypeQuals, Expr *E);
3111 };
3112 
3113 /// Represents an extended address space qualifier where the input address space
3114 /// value is dependent. Non-dependent address spaces are not represented with a
3115 /// special Type subclass; they are stored on an ExtQuals node as part of a QualType.
3116 ///
3117 /// For example:
3118 /// \code
3119 /// template<typename T, int AddrSpace>
3120 /// class AddressSpace {
3121 /// typedef T __attribute__((address_space(AddrSpace))) type;
3122 /// }
3123 /// \endcode
3124 class DependentAddressSpaceType : public Type, public llvm::FoldingSetNode {
3125  friend class ASTContext;
3126 
3127  const ASTContext &Context;
3128  Expr *AddrSpaceExpr;
3129  QualType PointeeType;
3130  SourceLocation loc;
3131 
3132  DependentAddressSpaceType(const ASTContext &Context, QualType PointeeType,
3133  QualType can, Expr *AddrSpaceExpr,
3134  SourceLocation loc);
3135 
3136 public:
3137  Expr *getAddrSpaceExpr() const { return AddrSpaceExpr; }
3138  QualType getPointeeType() const { return PointeeType; }
3139  SourceLocation getAttributeLoc() const { return loc; }
3140 
3141  bool isSugared() const { return false; }
3142  QualType desugar() const { return QualType(this, 0); }
3143 
3144  static bool classof(const Type *T) {
3145  return T->getTypeClass() == DependentAddressSpace;
3146  }
3147 
3148  void Profile(llvm::FoldingSetNodeID &ID) {
3149  Profile(ID, Context, getPointeeType(), getAddrSpaceExpr());
3150  }
3151 
3152  static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
3153  QualType PointeeType, Expr *AddrSpaceExpr);
3154 };
3155 
3156 /// Represents an extended vector type where either the type or size is
3157 /// dependent.
3158 ///
3159 /// For example:
3160 /// \code
3161 /// template<typename T, int Size>
3162 /// class vector {
3163 /// typedef T __attribute__((ext_vector_type(Size))) type;
3164 /// }
3165 /// \endcode
3166 class DependentSizedExtVectorType : public Type, public llvm::FoldingSetNode {
3167  friend class ASTContext;
3168 
3169  const ASTContext &Context;
3170  Expr *SizeExpr;
3171 
3172  /// The element type of the array.
3173  QualType ElementType;
3174 
3175  SourceLocation loc;
3176 
3177  DependentSizedExtVectorType(const ASTContext &Context, QualType ElementType,
3178  QualType can, Expr *SizeExpr, SourceLocation loc);
3179 
3180 public:
3181  Expr *getSizeExpr() const { return SizeExpr; }
3182  QualType getElementType() const { return ElementType; }
3183  SourceLocation getAttributeLoc() const { return loc; }
3184 
3185  bool isSugared() const { return false; }
3186  QualType desugar() const { return QualType(this, 0); }
3187 
3188  static bool classof(const Type *T) {
3189  return T->getTypeClass() == DependentSizedExtVector;
3190  }
3191 
3192  void Profile(llvm::FoldingSetNodeID &ID) {
3193  Profile(ID, Context, getElementType(), getSizeExpr());
3194  }
3195 
3196  static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
3197  QualType ElementType, Expr *SizeExpr);
3198 };
3199 
3200 
3201 /// Represents a GCC generic vector type. This type is created using
3202 /// __attribute__((vector_size(n)), where "n" specifies the vector size in
3203 /// bytes; or from an Altivec __vector or vector declaration.
3204 /// Since the constructor takes the number of vector elements, the
3205 /// client is responsible for converting the size into the number of elements.
3206 class VectorType : public Type, public llvm::FoldingSetNode {
3207 public:
3208  enum VectorKind {
3209  /// not a target-specific vector type
3211 
3212  /// is AltiVec vector
3214 
3215  /// is AltiVec 'vector Pixel'
3217 
3218  /// is AltiVec 'vector bool ...'
3220 
3221  /// is ARM Neon vector
3223 
3224  /// is ARM Neon polynomial vector
3225  NeonPolyVector
3226  };
3227 
3228 protected:
3229  friend class ASTContext; // ASTContext creates these.
3230 
3231  /// The element type of the vector.
3233 
3234  VectorType(QualType vecType, unsigned nElements, QualType canonType,
3235  VectorKind vecKind);
3236 
3237  VectorType(TypeClass tc, QualType vecType, unsigned nElements,
3238  QualType canonType, VectorKind vecKind);
3239 
3240 public:
3241  QualType getElementType() const { return ElementType; }
3242  unsigned getNumElements() const { return VectorTypeBits.NumElements; }
3243 
3244  static bool isVectorSizeTooLarge(unsigned NumElements) {
3245  return NumElements > VectorTypeBitfields::MaxNumElements;
3246  }
3247 
3248  bool isSugared() const { return false; }
3249  QualType desugar() const { return QualType(this, 0); }
3250 
3252  return VectorKind(VectorTypeBits.VecKind);
3253  }
3254 
3255  void Profile(llvm::FoldingSetNodeID &ID) {
3256  Profile(ID, getElementType(), getNumElements(),
3257  getTypeClass(), getVectorKind());
3258  }
3259 
3260  static void Profile(llvm::FoldingSetNodeID &ID, QualType ElementType,
3261  unsigned NumElements, TypeClass TypeClass,
3262  VectorKind VecKind) {
3263  ID.AddPointer(ElementType.getAsOpaquePtr());
3264  ID.AddInteger(NumElements);
3265  ID.AddInteger(TypeClass);
3266  ID.AddInteger(VecKind);
3267  }
3268 
3269  static bool classof(const Type *T) {
3270  return T->getTypeClass() == Vector || T->getTypeClass() == ExtVector;
3271  }
3272 };
3273 
3274 /// Represents a vector type where either the type or size is dependent.
3275 ////
3276 /// For example:
3277 /// \code
3278 /// template<typename T, int Size>
3279 /// class vector {
3280 /// typedef T __attribute__((vector_size(Size))) type;
3281 /// }
3282 /// \endcode
3283 class DependentVectorType : public Type, public llvm::FoldingSetNode {
3284  friend class ASTContext;
3285 
3286  const ASTContext &Context;
3287  QualType ElementType;
3288  Expr *SizeExpr;
3289  SourceLocation Loc;
3290 
3291  DependentVectorType(const ASTContext &Context, QualType ElementType,
3292  QualType CanonType, Expr *SizeExpr,
3293  SourceLocation Loc, VectorType::VectorKind vecKind);
3294 
3295 public:
3296  Expr *getSizeExpr() const { return SizeExpr; }
3297  QualType getElementType() const { return ElementType; }
3298  SourceLocation getAttributeLoc() const { return Loc; }
3300  return VectorType::VectorKind(VectorTypeBits.VecKind);
3301  }
3302 
3303  bool isSugared() const { return false; }
3304  QualType desugar() const { return QualType(this, 0); }
3305 
3306  static bool classof(const Type *T) {
3307  return T->getTypeClass() == DependentVector;
3308  }
3309 
3310  void Profile(llvm::FoldingSetNodeID &ID) {
3311  Profile(ID, Context, getElementType(), getSizeExpr(), getVectorKind());
3312  }
3313 
3314  static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
3315  QualType ElementType, const Expr *SizeExpr,
3316  VectorType::VectorKind VecKind);
3317 };
3318 
3319 /// ExtVectorType - Extended vector type. This type is created using
3320 /// __attribute__((ext_vector_type(n)), where "n" is the number of elements.
3321 /// Unlike vector_size, ext_vector_type is only allowed on typedef's. This
3322 /// class enables syntactic extensions, like Vector Components for accessing
3323 /// points (as .xyzw), colors (as .rgba), and textures (modeled after OpenGL
3324 /// Shading Language).
3325 class ExtVectorType : public VectorType {
3326  friend class ASTContext; // ASTContext creates these.
3327 
3328  ExtVectorType(QualType vecType, unsigned nElements, QualType canonType)
3329  : VectorType(ExtVector, vecType, nElements, canonType, GenericVector) {}
3330 
3331 public:
3332  static int getPointAccessorIdx(char c) {
3333  switch (c) {
3334  default: return -1;
3335  case 'x': case 'r': return 0;
3336  case 'y': case 'g': return 1;
3337  case 'z': case 'b': return 2;
3338  case 'w': case 'a': return 3;
3339  }
3340  }
3341 
3342  static int getNumericAccessorIdx(char c) {
3343  switch (c) {
3344  default: return -1;
3345  case '0': return 0;
3346  case '1': return 1;
3347  case '2': return 2;
3348  case '3': return 3;
3349  case '4': return 4;
3350  case '5': return 5;
3351  case '6': return 6;
3352  case '7': return 7;
3353  case '8': return 8;
3354  case '9': return 9;
3355  case 'A':
3356  case 'a': return 10;
3357  case 'B':
3358  case 'b': return 11;
3359  case 'C':
3360  case 'c': return 12;
3361  case 'D':
3362  case 'd': return 13;
3363  case 'E':
3364  case 'e': return 14;
3365  case 'F':
3366  case 'f': return 15;
3367  }
3368  }
3369 
3370  static int getAccessorIdx(char c, bool isNumericAccessor) {
3371  if (isNumericAccessor)
3372  return getNumericAccessorIdx(c);
3373  else
3374  return getPointAccessorIdx(c);
3375  }
3376 
3377  bool isAccessorWithinNumElements(char c, bool isNumericAccessor) const {
3378  if (int idx = getAccessorIdx(c, isNumericAccessor)+1)
3379  return unsigned(idx-1) < getNumElements();
3380  return false;
3381  }
3382 
3383  bool isSugared() const { return false; }
3384  QualType desugar() const { return QualType(this, 0); }
3385 
3386  static bool classof(const Type *T) {
3387  return T->getTypeClass() == ExtVector;
3388  }
3389 };
3390 
3391 /// FunctionType - C99 6.7.5.3 - Function Declarators. This is the common base
3392 /// class of FunctionNoProtoType and FunctionProtoType.
3393 class FunctionType : public Type {
3394  // The type returned by the function.
3395  QualType ResultType;
3396 
3397 public:
3398  /// Interesting information about a specific parameter that can't simply
3399  /// be reflected in parameter's type. This is only used by FunctionProtoType
3400  /// but is in FunctionType to make this class available during the
3401  /// specification of the bases of FunctionProtoType.
3402  ///
3403  /// It makes sense to model language features this way when there's some
3404  /// sort of parameter-specific override (such as an attribute) that
3405  /// affects how the function is called. For example, the ARC ns_consumed
3406  /// attribute changes whether a parameter is passed at +0 (the default)
3407  /// or +1 (ns_consumed). This must be reflected in the function type,
3408  /// but isn't really a change to the parameter type.
3409  ///
3410  /// One serious disadvantage of modelling language features this way is
3411  /// that they generally do not work with language features that attempt
3412  /// to destructure types. For example, template argument deduction will
3413  /// not be able to match a parameter declared as
3414  /// T (*)(U)
3415  /// against an argument of type
3416  /// void (*)(__attribute__((ns_consumed)) id)
3417  /// because the substitution of T=void, U=id into the former will
3418  /// not produce the latter.
3420  enum {
3421  ABIMask = 0x0F,
3422  IsConsumed = 0x10,
3423  HasPassObjSize = 0x20,
3424  IsNoEscape = 0x40,
3425  };
3426  unsigned char Data = 0;
3427 
3428  public:
3429  ExtParameterInfo() = default;
3430 
3431  /// Return the ABI treatment of this parameter.
3432  ParameterABI getABI() const { return ParameterABI(Data & ABIMask); }
3434  ExtParameterInfo copy = *this;
3435  copy.Data = (copy.Data & ~ABIMask) | unsigned(kind);
3436  return copy;
3437  }
3438 
3439  /// Is this parameter considered "consumed" by Objective-C ARC?
3440  /// Consumed parameters must have retainable object type.
3441  bool isConsumed() const { return (Data & IsConsumed); }
3442  ExtParameterInfo withIsConsumed(bool consumed) const {
3443  ExtParameterInfo copy = *this;
3444  if (consumed)
3445  copy.Data |= IsConsumed;
3446  else
3447  copy.Data &= ~IsConsumed;
3448  return copy;
3449  }
3450 
3451  bool hasPassObjectSize() const { return Data & HasPassObjSize; }
3453  ExtParameterInfo Copy = *this;
3454  Copy.Data |= HasPassObjSize;
3455  return Copy;
3456  }
3457 
3458  bool isNoEscape() const { return Data & IsNoEscape; }
3459  ExtParameterInfo withIsNoEscape(bool NoEscape) const {
3460  ExtParameterInfo Copy = *this;
3461  if (NoEscape)
3462  Copy.Data |= IsNoEscape;
3463  else
3464  Copy.Data &= ~IsNoEscape;
3465  return Copy;
3466  }
3467 
3468  unsigned char getOpaqueValue() const { return Data; }
3469  static ExtParameterInfo getFromOpaqueValue(unsigned char data) {
3470  ExtParameterInfo result;
3471  result.Data = data;
3472  return result;
3473  }
3474 
3476  return lhs.Data == rhs.Data;
3477  }
3478 
3480  return lhs.Data != rhs.Data;
3481  }
3482  };
3483 
3484  /// A class which abstracts out some details necessary for
3485  /// making a call.
3486  ///
3487  /// It is not actually used directly for storing this information in
3488  /// a FunctionType, although FunctionType does currently use the
3489  /// same bit-pattern.
3490  ///
3491  // If you add a field (say Foo), other than the obvious places (both,
3492  // constructors, compile failures), what you need to update is
3493  // * Operator==
3494  // * getFoo
3495  // * withFoo
3496  // * functionType. Add Foo, getFoo.
3497  // * ASTContext::getFooType
3498  // * ASTContext::mergeFunctionTypes
3499  // * FunctionNoProtoType::Profile
3500  // * FunctionProtoType::Profile
3501  // * TypePrinter::PrintFunctionProto
3502  // * AST read and write
3503  // * Codegen
3504  class ExtInfo {
3505  friend class FunctionType;
3506 
3507  // Feel free to rearrange or add bits, but if you go over 12,
3508  // you'll need to adjust both the Bits field below and
3509  // Type::FunctionTypeBitfields.
3510 
3511  // | CC |noreturn|produces|nocallersavedregs|regparm|nocfcheck|
3512  // |0 .. 4| 5 | 6 | 7 |8 .. 10| 11 |
3513  //
3514  // regparm is either 0 (no regparm attribute) or the regparm value+1.
3515  enum { CallConvMask = 0x1F };
3516  enum { NoReturnMask = 0x20 };
3517  enum { ProducesResultMask = 0x40 };
3518  enum { NoCallerSavedRegsMask = 0x80 };
3519  enum { NoCfCheckMask = 0x800 };
3520  enum {
3521  RegParmMask = ~(CallConvMask | NoReturnMask | ProducesResultMask |
3522  NoCallerSavedRegsMask | NoCfCheckMask),
3523  RegParmOffset = 8
3524  }; // Assumed to be the last field
3525  uint16_t Bits = CC_C;
3526 
3527  ExtInfo(unsigned Bits) : Bits(static_cast<uint16_t>(Bits)) {}
3528 
3529  public:
3530  // Constructor with no defaults. Use this when you know that you
3531  // have all the elements (when reading an AST file for example).
3532  ExtInfo(bool noReturn, bool hasRegParm, unsigned regParm, CallingConv cc,
3533  bool producesResult, bool noCallerSavedRegs, bool NoCfCheck) {
3534  assert((!hasRegParm || regParm < 7) && "Invalid regparm value");
3535  Bits = ((unsigned)cc) | (noReturn ? NoReturnMask : 0) |
3536  (producesResult ? ProducesResultMask : 0) |
3537  (noCallerSavedRegs ? NoCallerSavedRegsMask : 0) |
3538  (hasRegParm ? ((regParm + 1) << RegParmOffset) : 0) |
3539  (NoCfCheck ? NoCfCheckMask : 0);
3540  }
3541 
3542  // Constructor with all defaults. Use when for example creating a
3543  // function known to use defaults.
3544  ExtInfo() = default;
3545 
3546  // Constructor with just the calling convention, which is an important part
3547  // of the canonical type.
3548  ExtInfo(CallingConv CC) : Bits(CC) {}
3549 
3550  bool getNoReturn() const { return Bits & NoReturnMask; }
3551  bool getProducesResult() const { return Bits & ProducesResultMask; }
3552  bool getNoCallerSavedRegs() const { return Bits & NoCallerSavedRegsMask; }
3553  bool getNoCfCheck() const { return Bits & NoCfCheckMask; }
3554  bool getHasRegParm() const { return (Bits >> RegParmOffset) != 0; }
3555 
3556  unsigned getRegParm() const {
3557  unsigned RegParm = (Bits & RegParmMask) >> RegParmOffset;
3558  if (RegParm > 0)
3559  --RegParm;
3560  return RegParm;
3561  }
3562 
3563  CallingConv getCC() const { return CallingConv(Bits & CallConvMask); }
3564 
3565  bool operator==(ExtInfo Other) const {
3566  return Bits == Other.Bits;
3567  }
3568  bool operator!=(ExtInfo Other) const {
3569  return Bits != Other.Bits;
3570  }
3571 
3572  // Note that we don't have setters. That is by design, use
3573  // the following with methods instead of mutating these objects.
3574 
3575  ExtInfo withNoReturn(bool noReturn) const {
3576  if (noReturn)
3577  return ExtInfo(Bits | NoReturnMask);
3578  else
3579  return ExtInfo(Bits & ~NoReturnMask);
3580  }
3581 
3582  ExtInfo withProducesResult(bool producesResult) const {
3583  if (producesResult)
3584  return ExtInfo(Bits | ProducesResultMask);
3585  else
3586  return ExtInfo(Bits & ~ProducesResultMask);
3587  }
3588 
3589  ExtInfo withNoCallerSavedRegs(bool noCallerSavedRegs) const {
3590  if (noCallerSavedRegs)
3591  return ExtInfo(Bits | NoCallerSavedRegsMask);
3592  else
3593  return ExtInfo(Bits & ~NoCallerSavedRegsMask);
3594  }
3595 
3596  ExtInfo withNoCfCheck(bool noCfCheck) const {
3597  if (noCfCheck)
3598  return ExtInfo(Bits | NoCfCheckMask);
3599  else
3600  return ExtInfo(Bits & ~NoCfCheckMask);
3601  }
3602 
3603  ExtInfo withRegParm(unsigned RegParm) const {
3604  assert(RegParm < 7 && "Invalid regparm value");
3605  return ExtInfo((Bits & ~RegParmMask) |
3606  ((RegParm + 1) << RegParmOffset));
3607  }
3608 
3610  return ExtInfo((Bits & ~CallConvMask) | (unsigned) cc);
3611  }
3612 
3613  void Profile(llvm::FoldingSetNodeID &ID) const {
3614  ID.AddInteger(Bits);
3615  }
3616  };
3617 
3618  /// A simple holder for a QualType representing a type in an
3619  /// exception specification. Unfortunately needed by FunctionProtoType
3620  /// because TrailingObjects cannot handle repeated types.
3622 
3623  /// A simple holder for various uncommon bits which do not fit in
3624  /// FunctionTypeBitfields. Aligned to alignof(void *) to maintain the
3625  /// alignment of subsequent objects in TrailingObjects. You must update
3626  /// hasExtraBitfields in FunctionProtoType after adding extra data here.
3627  struct alignas(void *) FunctionTypeExtraBitfields {
3628  /// The number of types in the exception specification.
3629  /// A whole unsigned is not needed here and according to
3630  /// [implimits] 8 bits would be enough here.
3632  };
3633 
3634 protected:
3636  QualType Canonical, bool Dependent,
3637  bool InstantiationDependent,
3638  bool VariablyModified, bool ContainsUnexpandedParameterPack,
3639  ExtInfo Info)
3640  : Type(tc, Canonical, Dependent, InstantiationDependent, VariablyModified,
3641  ContainsUnexpandedParameterPack),
3642  ResultType(res) {
3643  FunctionTypeBits.ExtInfo = Info.Bits;
3644  }
3645 
3647  return Qualifiers::fromFastMask(FunctionTypeBits.FastTypeQuals);
3648  }
3649 
3650 public:
3651  QualType getReturnType() const { return ResultType; }
3652 
3653  bool getHasRegParm() const { return getExtInfo().getHasRegParm(); }
3654  unsigned getRegParmType() const { return getExtInfo().getRegParm(); }
3655 
3656  /// Determine whether this function type includes the GNU noreturn
3657  /// attribute. The C++11 [[noreturn]] attribute does not affect the function
3658  /// type.
3659  bool getNoReturnAttr() const { return getExtInfo().getNoReturn(); }
3660 
3661  CallingConv getCallConv() const { return getExtInfo().getCC(); }
3662  ExtInfo getExtInfo() const { return ExtInfo(FunctionTypeBits.ExtInfo); }
3663 
3664  static_assert((~Qualifiers::FastMask & Qualifiers::CVRMask) == 0,
3665  "Const, volatile and restrict are assumed to be a subset of "
3666  "the fast qualifiers.");
3667 
3668  bool isConst() const { return getFastTypeQuals().hasConst(); }
3669  bool isVolatile() const { return getFastTypeQuals().hasVolatile(); }
3670  bool isRestrict() const { return getFastTypeQuals().hasRestrict(); }
3671 
3672  /// Determine the type of an expression that calls a function of
3673  /// this type.
3674  QualType getCallResultType(const ASTContext &Context) const {
3675  return getReturnType().getNonLValueExprType(Context);
3676  }
3677 
3678  static StringRef getNameForCallConv(CallingConv CC);
3679 
3680  static bool classof(const Type *T) {
3681  return T->getTypeClass() == FunctionNoProto ||
3682  T->getTypeClass() == FunctionProto;
3683  }
3684 };
3685 
3686 /// Represents a K&R-style 'int foo()' function, which has
3687 /// no information available about its arguments.
3688 class FunctionNoProtoType : public FunctionType, public llvm::FoldingSetNode {
3689  friend class ASTContext; // ASTContext creates these.
3690 
3692  : FunctionType(FunctionNoProto, Result, Canonical,
3693  /*Dependent=*/false, /*InstantiationDependent=*/false,
3694  Result->isVariablyModifiedType(),
3695  /*ContainsUnexpandedParameterPack=*/false, Info) {}
3696 
3697 public:
3698  // No additional state past what FunctionType provides.
3699 
3700  bool isSugared() const { return false; }
3701  QualType desugar() const { return QualType(this, 0); }
3702 
3703  void Profile(llvm::FoldingSetNodeID &ID) {
3704  Profile(ID, getReturnType(), getExtInfo());
3705  }
3706 
3707  static void Profile(llvm::FoldingSetNodeID &ID, QualType ResultType,
3708  ExtInfo Info) {
3709  Info.Profile(ID);
3710  ID.AddPointer(ResultType.getAsOpaquePtr());
3711  }
3712 
3713  static bool classof(const Type *T) {
3714  return T->getTypeClass() == FunctionNoProto;
3715  }
3716 };
3717 
3718 /// Represents a prototype with parameter type info, e.g.
3719 /// 'int foo(int)' or 'int foo(void)'. 'void' is represented as having no
3720 /// parameters, not as having a single void parameter. Such a type can have
3721 /// an exception specification, but this specification is not part of the
3722 /// canonical type. FunctionProtoType has several trailing objects, some of
3723 /// which optional. For more information about the trailing objects see
3724 /// the first comment inside FunctionProtoType.
3726  : public FunctionType,
3727  public llvm::FoldingSetNode,
3728  private llvm::TrailingObjects<
3729  FunctionProtoType, QualType, FunctionType::FunctionTypeExtraBitfields,
3730  FunctionType::ExceptionType, Expr *, FunctionDecl *,
3731  FunctionType::ExtParameterInfo, Qualifiers> {
3732  friend class ASTContext; // ASTContext creates these.
3733  friend TrailingObjects;
3734 
3735  // FunctionProtoType is followed by several trailing objects, some of
3736  // which optional. They are in order:
3737  //
3738  // * An array of getNumParams() QualType holding the parameter types.
3739  // Always present. Note that for the vast majority of FunctionProtoType,
3740  // these will be the only trailing objects.
3741  //
3742  // * Optionally if some extra data is stored in FunctionTypeExtraBitfields
3743  // (see FunctionTypeExtraBitfields and FunctionTypeBitfields):
3744  // a single FunctionTypeExtraBitfields. Present if and only if
3745  // hasExtraBitfields() is true.
3746  //
3747  // * Optionally exactly one of:
3748  // * an array of getNumExceptions() ExceptionType,
3749  // * a single Expr *,
3750  // * a pair of FunctionDecl *,
3751  // * a single FunctionDecl *
3752  // used to store information about the various types of exception
3753  // specification. See getExceptionSpecSize for the details.
3754  //
3755  // * Optionally an array of getNumParams() ExtParameterInfo holding
3756  // an ExtParameterInfo for each of the parameters. Present if and
3757  // only if hasExtParameterInfos() is true.
3758  //
3759  // * Optionally a Qualifiers object to represent extra qualifiers that can't
3760  // be represented by FunctionTypeBitfields.FastTypeQuals. Present if and only
3761  // if hasExtQualifiers() is true.
3762  //
3763  // The optional FunctionTypeExtraBitfields has to be before the data
3764  // related to the exception specification since it contains the number
3765  // of exception types.
3766  //
3767  // We put the ExtParameterInfos last. If all were equal, it would make
3768  // more sense to put these before the exception specification, because
3769  // it's much easier to skip past them compared to the elaborate switch
3770  // required to skip the exception specification. However, all is not
3771  // equal; ExtParameterInfos are used to model very uncommon features,
3772  // and it's better not to burden the more common paths.
3773 
3774 public:
3775  /// Holds information about the various types of exception specification.
3776  /// ExceptionSpecInfo is not stored as such in FunctionProtoType but is
3777  /// used to group together the various bits of information about the
3778  /// exception specification.
3780  /// The kind of exception specification this is.
3782 
3783  /// Explicitly-specified list of exception types.
3785 
3786  /// Noexcept expression, if this is a computed noexcept specification.
3787  Expr *NoexceptExpr = nullptr;
3788 
3789  /// The function whose exception specification this is, for
3790  /// EST_Unevaluated and EST_Uninstantiated.
3791  FunctionDecl *SourceDecl = nullptr;
3792 
3793  /// The function template whose exception specification this is instantiated
3794  /// from, for EST_Uninstantiated.
3795  FunctionDecl *SourceTemplate = nullptr;
3796 
3797  ExceptionSpecInfo() = default;
3798 
3800  };
3801 
3802  /// Extra information about a function prototype. ExtProtoInfo is not
3803  /// stored as such in FunctionProtoType but is used to group together
3804  /// the various bits of extra information about a function prototype.
3805  struct ExtProtoInfo {
3807  bool Variadic : 1;
3810  RefQualifierKind RefQualifier = RQ_None;
3812  const ExtParameterInfo *ExtParameterInfos = nullptr;
3813 
3814  ExtProtoInfo() : Variadic(false), HasTrailingReturn(false) {}
3815 
3817  : ExtInfo(CC), Variadic(false), HasTrailingReturn(false) {}
3818 
3820  ExtProtoInfo Result(*this);
3821  Result.ExceptionSpec = ESI;
3822  return Result;
3823  }
3824  };
3825 
3826 private:
3827  unsigned numTrailingObjects(OverloadToken<QualType>) const {
3828  return getNumParams();
3829  }
3830 
3831  unsigned numTrailingObjects(OverloadToken<FunctionTypeExtraBitfields>) const {
3832  return hasExtraBitfields();
3833  }
3834 
3835  unsigned numTrailingObjects(OverloadToken<ExceptionType>) const {
3836  return getExceptionSpecSize().NumExceptionType;
3837  }
3838 
3839  unsigned numTrailingObjects(OverloadToken<Expr *>) const {
3840  return getExceptionSpecSize().NumExprPtr;
3841  }
3842 
3843  unsigned numTrailingObjects(OverloadToken<FunctionDecl *>) const {
3844  return getExceptionSpecSize().NumFunctionDeclPtr;
3845  }
3846 
3847  unsigned numTrailingObjects(OverloadToken<ExtParameterInfo>) const {
3848  return hasExtParameterInfos() ? getNumParams() : 0;
3849  }
3850 
3851  /// Determine whether there are any argument types that
3852  /// contain an unexpanded parameter pack.
3853  static bool containsAnyUnexpandedParameterPack(const QualType *ArgArray,
3854  unsigned numArgs) {
3855  for (unsigned Idx = 0; Idx < numArgs; ++Idx)
3856  if (ArgArray[Idx]->containsUnexpandedParameterPack())
3857  return true;
3858 
3859  return false;
3860  }
3861 
3863  QualType canonical, const ExtProtoInfo &epi);
3864 
3865  /// This struct is returned by getExceptionSpecSize and is used to
3866  /// translate an ExceptionSpecificationType to the number and kind
3867  /// of trailing objects related to the exception specification.
3868  struct ExceptionSpecSizeHolder {
3869  unsigned NumExceptionType;
3870  unsigned NumExprPtr;
3871  unsigned NumFunctionDeclPtr;
3872  };
3873 
3874  /// Return the number and kind of trailing objects
3875  /// related to the exception specification.
3876  static ExceptionSpecSizeHolder
3877  getExceptionSpecSize(ExceptionSpecificationType EST, unsigned NumExceptions) {
3878  switch (EST) {
3879  case EST_None:
3880  case EST_DynamicNone:
3881  case EST_MSAny:
3882  case EST_BasicNoexcept:
3883  case EST_Unparsed:
3884  case EST_NoThrow:
3885  return {0, 0, 0};
3886 
3887  case EST_Dynamic:
3888  return {NumExceptions, 0, 0};
3889 
3890  case EST_DependentNoexcept:
3891  case EST_NoexceptFalse:
3892  case EST_NoexceptTrue:
3893  return {0, 1, 0};
3894 
3895  case EST_Uninstantiated:
3896  return {0, 0, 2};
3897 
3898  case EST_Unevaluated:
3899  return {0, 0, 1};
3900  }
3901  llvm_unreachable("bad exception specification kind");
3902  }
3903 
3904  /// Return the number and kind of trailing objects
3905  /// related to the exception specification.
3906  ExceptionSpecSizeHolder getExceptionSpecSize() const {
3907  return getExceptionSpecSize(getExceptionSpecType(), getNumExceptions());
3908  }
3909 
3910  /// Whether the trailing FunctionTypeExtraBitfields is present.
3911  static bool hasExtraBitfields(ExceptionSpecificationType EST) {
3912  // If the exception spec type is EST_Dynamic then we have > 0 exception
3913  // types and the exact number is stored in FunctionTypeExtraBitfields.
3914  return EST == EST_Dynamic;
3915  }
3916 
3917  /// Whether the trailing FunctionTypeExtraBitfields is present.
3918  bool hasExtraBitfields() const {
3919  return hasExtraBitfields(getExceptionSpecType());
3920  }
3921 
3922  bool hasExtQualifiers() const {
3923  return FunctionTypeBits.HasExtQuals;
3924  }
3925 
3926 public:
3927  unsigned getNumParams() const { return FunctionTypeBits.NumParams; }
3928 
3929  QualType getParamType(unsigned i) const {
3930  assert(i < getNumParams() && "invalid parameter index");
3931  return param_type_begin()[i];
3932  }
3933 
3935  return llvm::makeArrayRef(param_type_begin(), param_type_end());
3936  }
3937 
3939  ExtProtoInfo EPI;
3940  EPI.ExtInfo = getExtInfo();
3941  EPI.Variadic = isVariadic();
3942  EPI.HasTrailingReturn = hasTrailingReturn();
3943  EPI.ExceptionSpec.Type = getExceptionSpecType();
3944  EPI.TypeQuals = getMethodQuals();
3945  EPI.RefQualifier = getRefQualifier();
3946  if (EPI.ExceptionSpec.Type == EST_Dynamic) {
3947  EPI.ExceptionSpec.Exceptions = exceptions();
3948  } else if (isComputedNoexcept(EPI.ExceptionSpec.Type)) {
3949  EPI.ExceptionSpec.NoexceptExpr = getNoexceptExpr();
3950  } else if (EPI.ExceptionSpec.Type == EST_Uninstantiated) {
3951  EPI.ExceptionSpec.SourceDecl = getExceptionSpecDecl();
3952  EPI.ExceptionSpec.SourceTemplate = getExceptionSpecTemplate();
3953  } else if (EPI.ExceptionSpec.Type == EST_Unevaluated) {
3954  EPI.ExceptionSpec.SourceDecl = getExceptionSpecDecl();
3955  }
3956  EPI.ExtParameterInfos = getExtParameterInfosOrNull();
3957  return EPI;
3958  }
3959 
3960  /// Get the kind of exception specification on this function.
3962  return static_cast<ExceptionSpecificationType>(
3963  FunctionTypeBits.ExceptionSpecType);
3964  }
3965 
3966  /// Return whether this function has any kind of exception spec.
3967  bool hasExceptionSpec() const { return getExceptionSpecType() != EST_None; }
3968 
3969  /// Return whether this function has a dynamic (throw) exception spec.
3971  return isDynamicExceptionSpec(getExceptionSpecType());
3972  }
3973 
3974  /// Return whether this function has a noexcept exception spec.
3976  return isNoexceptExceptionSpec(getExceptionSpecType());
3977  }
3978 
3979  /// Return whether this function has a dependent exception spec.
3980  bool hasDependentExceptionSpec() const;
3981 
3982  /// Return whether this function has an instantiation-dependent exception
3983  /// spec.
3984  bool hasInstantiationDependentExceptionSpec() const;
3985 
3986  /// Return the number of types in the exception specification.
3987  unsigned getNumExceptions() const {
3988  return getExceptionSpecType() == EST_Dynamic
3989  ? getTrailingObjects<FunctionTypeExtraBitfields>()
3990  ->NumExceptionType
3991  : 0;
3992  }
3993 
3994  /// Return the ith exception type, where 0 <= i < getNumExceptions().
3995  QualType getExceptionType(unsigned i) const {
3996  assert(i < getNumExceptions() && "Invalid exception number!");
3997  return exception_begin()[i];
3998  }
3999 
4000  /// Return the expression inside noexcept(expression), or a null pointer
4001  /// if there is none (because the exception spec is not of this form).
4003  if (!isComputedNoexcept(getExceptionSpecType()))
4004  return nullptr;
4005  return *getTrailingObjects<Expr *>();
4006  }
4007 
4008  /// If this function type has an exception specification which hasn't
4009  /// been determined yet (either because it has not been evaluated or because
4010  /// it has not been instantiated), this is the function whose exception
4011  /// specification is represented by this type.
4013  if (getExceptionSpecType() != EST_Uninstantiated &&
4014  getExceptionSpecType() != EST_Unevaluated)
4015  return nullptr;
4016  return getTrailingObjects<FunctionDecl *>()[0];
4017  }
4018 
4019  /// If this function type has an uninstantiated exception
4020  /// specification, this is the function whose exception specification
4021  /// should be instantiated to find the exception specification for
4022  /// this type.
4024  if (getExceptionSpecType() != EST_Uninstantiated)
4025  return nullptr;
4026  return getTrailingObjects<FunctionDecl *>()[1];
4027  }
4028 
4029  /// Determine whether this function type has a non-throwing exception
4030  /// specification.
4031  CanThrowResult canThrow() const;
4032 
4033  /// Determine whether this function type has a non-throwing exception
4034  /// specification. If this depends on template arguments, returns
4035  /// \c ResultIfDependent.
4036  bool isNothrow(bool ResultIfDependent = false) const {
4037  return ResultIfDependent ? canThrow() != CT_Can : canThrow() == CT_Cannot;
4038  }
4039 
4040  /// Whether this function prototype is variadic.
4041  bool isVariadic() const { return FunctionTypeBits.Variadic; }
4042 
4043  /// Determines whether this function prototype contains a
4044  /// parameter pack at the end.
4045  ///
4046  /// A function template whose last parameter is a parameter pack can be
4047  /// called with an arbitrary number of arguments, much like a variadic
4048  /// function.
4049  bool isTemplateVariadic() const;
4050 
4051  /// Whether this function prototype has a trailing return type.
4052  bool hasTrailingReturn() const { return FunctionTypeBits.HasTrailingReturn; }
4053 
4055  if (hasExtQualifiers())
4056  return *getTrailingObjects<Qualifiers>();
4057  else
4058  return getFastTypeQuals();
4059  }
4060 
4061  /// Retrieve the ref-qualifier associated with this function type.
4063  return static_cast<RefQualifierKind>(FunctionTypeBits.RefQualifier);
4064  }
4065 
4067  using param_type_range = llvm::iterator_range<param_type_iterator>;
4068 
4070  return param_type_range(param_type_begin(), param_type_end());
4071  }
4072 
4074  return getTrailingObjects<QualType>();
4075  }
4076 
4078  return param_type_begin() + getNumParams();
4079  }
4080 
4081  using exception_iterator = const QualType *;
4082 
4084  return llvm::makeArrayRef(exception_begin(), exception_end());
4085  }
4086 
4088  return reinterpret_cast<exception_iterator>(
4089  getTrailingObjects<ExceptionType>());
4090  }
4091 
4093  return exception_begin() + getNumExceptions();
4094  }
4095 
4096  /// Is there any interesting extra information for any of the parameters
4097  /// of this function type?
4098  bool hasExtParameterInfos() const {
4099  return FunctionTypeBits.HasExtParameterInfos;
4100  }
4101 
4103  assert(hasExtParameterInfos());
4104  return ArrayRef<ExtParameterInfo>(getTrailingObjects<ExtParameterInfo>(),
4105  getNumParams());
4106  }
4107 
4108  /// Return a pointer to the beginning of the array of extra parameter
4109  /// information, if present, or else null if none of the parameters
4110  /// carry it. This is equivalent to getExtProtoInfo().ExtParameterInfos.
4112  if (!hasExtParameterInfos())
4113  return nullptr;
4114  return getTrailingObjects<ExtParameterInfo>();
4115  }
4116 
4118  assert(I < getNumParams() && "parameter index out of range");
4119  if (hasExtParameterInfos())
4120  return getTrailingObjects<ExtParameterInfo>()[I];
4121  return ExtParameterInfo();
4122  }
4123 
4124  ParameterABI getParameterABI(unsigned I) const {
4125  assert(I < getNumParams() && "parameter index out of range");
4126  if (hasExtParameterInfos())
4127  return getTrailingObjects<ExtParameterInfo>()[I].getABI();
4128  return ParameterABI::Ordinary;
4129  }
4130 
4131  bool isParamConsumed(unsigned I) const {
4132  assert(I < getNumParams() && "parameter index out of range");
4133  if (hasExtParameterInfos())
4134  return getTrailingObjects<ExtParameterInfo>()[I].isConsumed();
4135  return false;
4136  }
4137 
4138  bool isSugared() const { return false; }
4139  QualType desugar() const { return QualType(this, 0); }
4140 
4141  void printExceptionSpecification(raw_ostream &OS,
4142  const PrintingPolicy &Policy) const;
4143 
4144  static bool classof(const Type *T) {
4145  return T->getTypeClass() == FunctionProto;
4146  }
4147 
4148  void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx);
4149  static void Profile(llvm::FoldingSetNodeID &ID, QualType Result,
4150  param_type_iterator ArgTys, unsigned NumArgs,
4151  const ExtProtoInfo &EPI, const ASTContext &Context,
4152  bool Canonical);
4153 };
4154 
4155 /// Represents the dependent type named by a dependently-scoped
4156 /// typename using declaration, e.g.
4157 /// using typename Base<T>::foo;
4158 ///
4159 /// Template instantiation turns these into the underlying type.
4160 class UnresolvedUsingType : public Type {
4161  friend class ASTContext; // ASTContext creates these.
4162 
4164 
4166  : Type(UnresolvedUsing, QualType(), true, true, false,
4167  /*ContainsUnexpandedParameterPack=*/false),
4168  Decl(const_cast<UnresolvedUsingTypenameDecl*>(D)) {}
4169 
4170 public:
4171  UnresolvedUsingTypenameDecl *getDecl() const { return Decl; }
4172 
4173  bool isSugared() const { return false; }
4174  QualType desugar() const { return QualType(this, 0); }
4175 
4176  static bool classof(const Type *T) {
4177  return T->getTypeClass() == UnresolvedUsing;
4178  }
4179 
4180  void Profile(llvm::FoldingSetNodeID &ID) {
4181  return Profile(ID, Decl);
4182  }
4183 
4184  static void Profile(llvm::FoldingSetNodeID &ID,
4186  ID.AddPointer(D);
4187  }
4188 };
4189 
4190 class TypedefType : public Type {
4192 
4193 protected:
4194  friend class ASTContext; // ASTContext creates these.
4195 
4197  : Type(tc, can, can->isDependentType(),
4198  can->isInstantiationDependentType(),
4199  can->isVariablyModifiedType(),
4200  /*ContainsUnexpandedParameterPack=*/false),
4201  Decl(const_cast<TypedefNameDecl*>(D)) {
4202  assert(!isa<TypedefType>(can) && "Invalid canonical type");
4203  }
4204 
4205 public:
4206  TypedefNameDecl *getDecl() const { return Decl; }
4207 
4208  bool isSugared() const { return true; }
4209  QualType desugar() const;
4210 
4211  static bool classof(const Type *T) { return T->getTypeClass() == Typedef; }
4212 };
4213 
4214 /// Sugar type that represents a type that was qualified by a qualifier written
4215 /// as a macro invocation.
4216 class MacroQualifiedType : public Type {
4217  friend class ASTContext; // ASTContext creates these.
4218 
4219  QualType UnderlyingTy;
4220  const IdentifierInfo *MacroII;
4221 
4222  MacroQualifiedType(QualType UnderlyingTy, QualType CanonTy,
4223  const IdentifierInfo *MacroII)
4224  : Type(MacroQualified, CanonTy, UnderlyingTy->isDependentType(),
4225  UnderlyingTy->isInstantiationDependentType(),
4226  UnderlyingTy->isVariablyModifiedType(),
4227  UnderlyingTy->containsUnexpandedParameterPack()),
4228  UnderlyingTy(UnderlyingTy), MacroII(MacroII) {
4229  assert(isa<AttributedType>(UnderlyingTy) &&
4230  "Expected a macro qualified type to only wrap attributed types.");
4231  }
4232 
4233 public:
4234  const IdentifierInfo *getMacroIdentifier() const { return MacroII; }
4235  QualType getUnderlyingType() const { return UnderlyingTy; }
4236 
4237  /// Return this attributed type's modified type with no qualifiers attached to
4238  /// it.
4239  QualType getModifiedType() const;
4240 
4241  bool isSugared() const { return true; }
4242  QualType desugar() const;
4243 
4244  static bool classof(const Type *T) {
4245  return T->getTypeClass() == MacroQualified;
4246  }
4247 };
4248 
4249 /// Represents a `typeof` (or __typeof__) expression (a GCC extension).
4250 class TypeOfExprType : public Type {
4251  Expr *TOExpr;
4252 
4253 protected:
4254  friend class ASTContext; // ASTContext creates these.
4255 
4256  TypeOfExprType(Expr *E, QualType can = QualType());
4257 
4258 public:
4259  Expr *getUnderlyingExpr() const { return TOExpr; }
4260 
4261  /// Remove a single level of sugar.
4262  QualType desugar() const;
4263 
4264  /// Returns whether this type directly provides sugar.
4265  bool isSugared() const;
4266 
4267  static bool classof(const Type *T) { return T->getTypeClass() == TypeOfExpr; }
4268 };
4269 
4270 /// Internal representation of canonical, dependent
4271 /// `typeof(expr)` types.
4272 ///
4273 /// This class is used internally by the ASTContext to manage
4274 /// canonical, dependent types, only. Clients will only see instances
4275 /// of this class via TypeOfExprType nodes.
4277  : public TypeOfExprType, public llvm::FoldingSetNode {
4278  const ASTContext &Context;
4279 
4280 public:
4282  : TypeOfExprType(E), Context(Context) {}
4283 
4284  void Profile(llvm::FoldingSetNodeID &ID) {
4285  Profile(ID, Context, getUnderlyingExpr());
4286  }
4287 
4288  static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
4289  Expr *E);
4290 };
4291 
4292 /// Represents `typeof(type)`, a GCC extension.
4293 class TypeOfType : public Type {
4294  friend class ASTContext; // ASTContext creates these.
4295 
4296  QualType TOType;
4297 
4298  TypeOfType(QualType T, QualType can)
4299  : Type(TypeOf, can, T->isDependentType(),
4300  T->isInstantiationDependentType(),
4301  T->isVariablyModifiedType(),
4302  T->containsUnexpandedParameterPack()),
4303  TOType(T) {
4304  assert(!isa<TypedefType>(can) && "Invalid canonical type");
4305  }
4306 
4307 public:
4308  QualType getUnderlyingType() const { return TOType; }
4309 
4310  /// Remove a single level of sugar.
4311  QualType desugar() const { return getUnderlyingType(); }
4312 
4313  /// Returns whether this type directly provides sugar.
4314  bool isSugared() const { return true; }
4315 
4316  static bool classof(const Type *T) { return T->getTypeClass() == TypeOf; }
4317 };
4318 
4319 /// Represents the type `decltype(expr)` (C++11).
4320 class DecltypeType : public Type {
4321  Expr *E;
4322  QualType UnderlyingType;
4323 
4324 protected:
4325  friend class ASTContext; // ASTContext creates these.
4326 
4327  DecltypeType(Expr *E, QualType underlyingType, QualType can = QualType());
4328 
4329 public:
4330  Expr *getUnderlyingExpr() const { return E; }
4331  QualType getUnderlyingType() const { return UnderlyingType; }
4332 
4333  /// Remove a single level of sugar.
4334  QualType desugar() const;
4335 
4336  /// Returns whether this type directly provides sugar.
4337  bool isSugared() const;
4338 
4339  static bool classof(const Type *T) { return T->getTypeClass() == Decltype; }
4340 };
4341 
4342 /// Internal representation of canonical, dependent
4343 /// decltype(expr) types.
4344 ///
4345 /// This class is used internally by the ASTContext to manage
4346 /// canonical, dependent types, only. Clients will only see instances
4347 /// of this class via DecltypeType nodes.
4348 class DependentDecltypeType : public DecltypeType, public llvm::FoldingSetNode {
4349  const ASTContext &Context;
4350 
4351 public:
4352  DependentDecltypeType(const ASTContext &Context, Expr *E);
4353 
4354  void Profile(llvm::FoldingSetNodeID &ID) {
4355  Profile(ID, Context, getUnderlyingExpr());
4356  }
4357 
4358  static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
4359  Expr *E);
4360 };
4361 
4362 /// A unary type transform, which is a type constructed from another.
4363 class UnaryTransformType : public Type {
4364 public:
4365  enum UTTKind {
4366  EnumUnderlyingType
4367  };
4368 
4369 private:
4370  /// The untransformed type.
4371  QualType BaseType;
4372 
4373  /// The transformed type if not dependent, otherwise the same as BaseType.
4374  QualType UnderlyingType;
4375 
4376  UTTKind UKind;
4377 
4378 protected:
4379  friend class ASTContext;
4380 
4381  UnaryTransformType(QualType BaseTy, QualType UnderlyingTy, UTTKind UKind,
4382  QualType CanonicalTy);
4383 
4384 public:
4385  bool isSugared() const { return !isDependentType(); }
4386  QualType desugar() const { return UnderlyingType; }
4387 
4388  QualType getUnderlyingType() const { return UnderlyingType; }
4389  QualType getBaseType() const { return BaseType; }
4390 
4391  UTTKind getUTTKind() const { return UKind; }
4392 
4393  static bool classof(const Type *T) {
4394  return T->getTypeClass() == UnaryTransform;
4395  }
4396 };
4397 
4398 /// Internal representation of canonical, dependent
4399 /// __underlying_type(type) types.
4400 ///
4401 /// This class is used internally by the ASTContext to manage
4402 /// canonical, dependent types, only. Clients will only see instances
4403 /// of this class via UnaryTransformType nodes.
4405  public llvm::FoldingSetNode {
4406 public:
4408  UTTKind UKind);
4409 
4410  void Profile(llvm::FoldingSetNodeID &ID) {
4411  Profile(ID, getBaseType(), getUTTKind());
4412  }
4413 
4414  static void Profile(llvm::FoldingSetNodeID &ID, QualType BaseType,
4415  UTTKind UKind) {
4416  ID.AddPointer(BaseType.getAsOpaquePtr());
4417  ID.AddInteger((unsigned)UKind);
4418  }
4419 };
4420 
4421 class TagType : public Type {
4422  friend class ASTReader;
4423 
4424  /// Stores the TagDecl associated with this type. The decl may point to any
4425  /// TagDecl that declares the entity.
4426  TagDecl *decl;
4427 
4428 protected:
4429  TagType(TypeClass TC, const TagDecl *D, QualType can);
4430 
4431 public:
4432  TagDecl *getDecl() const;
4433 
4434  /// Determines whether this type is in the process of being defined.
4435  bool isBeingDefined() const;
4436 
4437  static bool classof(const Type *T) {
4438  return T->getTypeClass() == Enum || T->getTypeClass() == Record;
4439  }
4440 };
4441 
4442 /// A helper class that allows the use of isa/cast/dyncast
4443 /// to detect TagType objects of structs/unions/classes.
4444 class RecordType : public TagType {
4445 protected:
4446  friend class ASTContext; // ASTContext creates these.
4447 
4448  explicit RecordType(const RecordDecl *D)
4449  : TagType(Record, reinterpret_cast<const TagDecl*>(D), QualType()) {}
4451  : TagType(TC, reinterpret_cast<const TagDecl*>(D), QualType()) {}
4452 
4453 public:
4454  RecordDecl *getDecl() const {
4455  return reinterpret_cast<RecordDecl*>(TagType::getDecl());
4456  }
4457 
4458  /// Recursively check all fields in the record for const-ness. If any field
4459  /// is declared const, return true. Otherwise, return false.
4460  bool hasConstFields() const;
4461 
4462  bool isSugared() const { return false; }
4463  QualType desugar() const { return QualType(this, 0); }
4464 
4465  static bool classof(const Type *T) { return T->getTypeClass() == Record; }
4466 };
4467 
4468 /// A helper class that allows the use of isa/cast/dyncast
4469 /// to detect TagType objects of enums.
4470 class EnumType : public TagType {
4471  friend class ASTContext; // ASTContext creates these.
4472 
4473  explicit EnumType(const EnumDecl *D)
4474  : TagType(Enum, reinterpret_cast<const TagDecl*>(D), QualType()) {}
4475 
4476 public:
4477  EnumDecl *getDecl() const {
4478  return reinterpret_cast<EnumDecl*>(TagType::getDecl());
4479  }
4480 
4481  bool isSugared() const { return false; }
4482  QualType desugar() const { return QualType(this, 0); }
4483 
4484  static bool classof(const Type *T) { return T->getTypeClass() == Enum; }
4485 };
4486 
4487 /// An attributed type is a type to which a type attribute has been applied.
4488 ///
4489 /// The "modified type" is the fully-sugared type to which the attributed
4490 /// type was applied; generally it is not canonically equivalent to the
4491 /// attributed type. The "equivalent type" is the minimally-desugared type
4492 /// which the type is canonically equivalent to.
4493 ///
4494 /// For example, in the following attributed type:
4495 /// int32_t __attribute__((vector_size(16)))
4496 /// - the modified type is the TypedefType for int32_t
4497 /// - the equivalent type is VectorType(16, int32_t)
4498 /// - the canonical type is VectorType(16, int)
4499 class AttributedType : public Type, public llvm::FoldingSetNode {
4500 public:
4501  using Kind = attr::Kind;
4502 
4503 private:
4504  friend class ASTContext; // ASTContext creates these
4505 
4506  QualType ModifiedType;
4507  QualType EquivalentType;
4508 
4509  AttributedType(QualType canon, attr::Kind attrKind, QualType modified,
4510  QualType equivalent)
4511  : Type(Attributed, canon, equivalent->isDependentType(),
4512  equivalent->isInstantiationDependentType(),
4513  equivalent->isVariablyModifiedType(),
4514  equivalent->containsUnexpandedParameterPack()),
4515  ModifiedType(modified), EquivalentType(equivalent) {
4516  AttributedTypeBits.AttrKind = attrKind;
4517  }
4518 
4519 public:
4520  Kind getAttrKind() const {
4521  return static_cast<Kind>(AttributedTypeBits.AttrKind);
4522  }
4523 
4524  QualType getModifiedType() const { return ModifiedType; }
4525  QualType getEquivalentType() const { return EquivalentType; }
4526 
4527  bool isSugared() const { return true; }
4528  QualType desugar() const { return getEquivalentType(); }
4529 
4530  /// Does this attribute behave like a type qualifier?
4531  ///
4532  /// A type qualifier adjusts a type to provide specialized rules for
4533  /// a specific object, like the standard const and volatile qualifiers.
4534  /// This includes attributes controlling things like nullability,
4535  /// address spaces, and ARC ownership. The value of the object is still
4536  /// largely described by the modified type.
4537  ///
4538  /// In contrast, many type attributes "rewrite" their modified type to
4539  /// produce a fundamentally different type, not necessarily related in any
4540  /// formalizable way to the original type. For example, calling convention
4541  /// and vector attributes are not simple type qualifiers.
4542  ///
4543  /// Type qualifiers are often, but not always, reflected in the canonical
4544  /// type.
4545  bool isQualifier() const;
4546 
4547  bool isMSTypeSpec() const;
4548 
4549  bool isCallingConv() const;
4550 
4551  llvm::Optional<NullabilityKind> getImmediateNullability() const;
4552 
4553  /// Retrieve the attribute kind corresponding to the given
4554  /// nullability kind.
4556  switch (kind) {
4558  return attr::TypeNonNull;
4559 
4561  return attr::TypeNullable;
4562 
4564  return attr::TypeNullUnspecified;
4565  }
4566  llvm_unreachable("Unknown nullability kind.");
4567  }
4568 
4569  /// Strip off the top-level nullability annotation on the given
4570  /// type, if it's there.
4571  ///
4572  /// \param T The type to strip. If the type is exactly an
4573  /// AttributedType specifying nullability (without looking through
4574  /// type sugar), the nullability is returned and this type changed
4575  /// to the underlying modified type.
4576  ///
4577  /// \returns the top-level nullability, if present.
4578  static Optional<NullabilityKind> stripOuterNullability(QualType &T);
4579 
4580  void Profile(llvm::FoldingSetNodeID &ID) {
4581  Profile(ID, getAttrKind(), ModifiedType, EquivalentType);
4582  }
4583 
4584  static void Profile(llvm::FoldingSetNodeID &ID, Kind attrKind,
4585  QualType modified, QualType equivalent) {
4586  ID.AddInteger(attrKind);
4587  ID.AddPointer(modified.getAsOpaquePtr());
4588  ID.AddPointer(equivalent.getAsOpaquePtr());
4589  }
4590 
4591  static bool classof(const Type *T) {
4592  return T->getTypeClass() == Attributed;
4593  }
4594 };
4595 
4596 class TemplateTypeParmType : public Type, public llvm::FoldingSetNode {
4597  friend class ASTContext; // ASTContext creates these
4598 
4599  // Helper data collector for canonical types.
4600  struct CanonicalTTPTInfo {
4601  unsigned Depth : 15;
4602  unsigned ParameterPack : 1;
4603  unsigned Index : 16;
4604  };
4605 
4606  union {
4607  // Info for the canonical type.
4608  CanonicalTTPTInfo CanTTPTInfo;
4609 
4610  // Info for the non-canonical type.
4612  };
4613 
4614  /// Build a non-canonical type.
4616  : Type(TemplateTypeParm, Canon, /*Dependent=*/true,
4617  /*InstantiationDependent=*/true,
4618  /*VariablyModified=*/false,
4619  Canon->containsUnexpandedParameterPack()),
4620  TTPDecl(TTPDecl) {}
4621 
4622  /// Build the canonical type.
4623  TemplateTypeParmType(unsigned D, unsigned I, bool PP)
4624  : Type(TemplateTypeParm, QualType(this, 0),
4625  /*Dependent=*/true,
4626  /*InstantiationDependent=*/true,
4627  /*VariablyModified=*/false, PP) {
4628  CanTTPTInfo.Depth = D;
4629  CanTTPTInfo.Index = I;
4630  CanTTPTInfo.ParameterPack = PP;
4631  }
4632 
4633  const CanonicalTTPTInfo& getCanTTPTInfo() const {
4634  QualType Can = getCanonicalTypeInternal();
4635  return Can->castAs<TemplateTypeParmType>()->CanTTPTInfo;
4636  }
4637 
4638 public:
4639  unsigned getDepth() const { return getCanTTPTInfo().Depth; }
4640  unsigned getIndex() const { return getCanTTPTInfo().Index; }
4641  bool isParameterPack() const { return getCanTTPTInfo().ParameterPack; }
4642 
4644  return isCanonicalUnqualified() ? nullptr : TTPDecl;
4645  }
4646 
4647  IdentifierInfo *getIdentifier() const;
4648 
4649  bool isSugared() const { return false; }
4650  QualType desugar() const { return QualType(this, 0); }
4651 
4652  void Profile(llvm::FoldingSetNodeID &ID) {
4653  Profile(ID, getDepth(), getIndex(), isParameterPack(), getDecl());
4654  }
4655 
4656  static void Profile(llvm::FoldingSetNodeID &ID, unsigned Depth,
4657  unsigned Index, bool ParameterPack,
4658  TemplateTypeParmDecl *TTPDecl) {
4659  ID.AddInteger(Depth);
4660  ID.AddInteger(Index);
4661  ID.AddBoolean(ParameterPack);
4662  ID.AddPointer(TTPDecl);
4663  }
4664 
4665  static bool classof(const Type *T) {
4666  return T->getTypeClass() == TemplateTypeParm;
4667  }
4668 };
4669 
4670 /// Represents the result of substituting a type for a template
4671 /// type parameter.
4672 ///
4673 /// Within an instantiated template, all template type parameters have
4674 /// been replaced with these. They are used solely to record that a
4675 /// type was originally written as a template type parameter;
4676 /// therefore they are never canonical.
4677 class SubstTemplateTypeParmType : public Type, public llvm::FoldingSetNode {
4678  friend class ASTContext;
4679 
4680  // The original type parameter.
4681  const TemplateTypeParmType *Replaced;
4682 
4684  : Type(SubstTemplateTypeParm, Canon, Canon->isDependentType(),
4685  Canon->isInstantiationDependentType(),
4686  Canon->isVariablyModifiedType(),
4687  Canon->containsUnexpandedParameterPack()),
4688  Replaced(Param) {}
4689 
4690 public:
4691  /// Gets the template parameter that was substituted for.
4693  return Replaced;
4694  }
4695 
4696  /// Gets the type that was substituted for the template
4697  /// parameter.
4699  return getCanonicalTypeInternal();
4700  }
4701 
4702  bool isSugared() const { return true; }
4703  QualType desugar() const { return getReplacementType(); }
4704 
4705  void Profile(llvm::FoldingSetNodeID &ID) {
4706  Profile(ID, getReplacedParameter(), getReplacementType());
4707  }
4708 
4709  static void Profile(llvm::FoldingSetNodeID &ID,
4710  const TemplateTypeParmType *Replaced,
4711  QualType Replacement) {
4712  ID.AddPointer(Replaced);
4713  ID.AddPointer(Replacement.getAsOpaquePtr());
4714  }
4715 
4716  static bool classof(const Type *T) {
4717  return T->getTypeClass() == SubstTemplateTypeParm;
4718  }
4719 };
4720 
4721 /// Represents the result of substituting a set of types for a template
4722 /// type parameter pack.
4723 ///
4724 /// When a pack expansion in the source code contains multiple parameter packs
4725 /// and those parameter packs correspond to different levels of template
4726 /// parameter lists, this type node is used to represent a template type
4727 /// parameter pack from an outer level, which has already had its argument pack
4728 /// substituted but that still lives within a pack expansion that itself
4729 /// could not be instantiated. When actually performing a substitution into
4730 /// that pack expansion (e.g., when all template parameters have corresponding
4731 /// arguments), this type will be replaced with the \c SubstTemplateTypeParmType
4732 /// at the current pack substitution index.
4733 class SubstTemplateTypeParmPackType : public Type, public llvm::FoldingSetNode {
4734  friend class ASTContext;
4735 
4736  /// The original type parameter.
4737  const TemplateTypeParmType *Replaced;
4738 
4739  /// A pointer to the set of template arguments that this
4740  /// parameter pack is instantiated with.
4741  const TemplateArgument *Arguments;
4742 
4744  QualType Canon,
4745  const TemplateArgument &ArgPack);
4746 
4747 public:
4748  IdentifierInfo *getIdentifier() const { return Replaced->getIdentifier(); }
4749 
4750  /// Gets the template parameter that was substituted for.
4752  return Replaced;
4753  }
4754 
4755  unsigned getNumArgs() const {
4756  return SubstTemplateTypeParmPackTypeBits.NumArgs;
4757  }
4758 
4759  bool isSugared() const { return false; }
4760  QualType desugar() const { return QualType(this, 0); }
4761 
4762  TemplateArgument getArgumentPack() const;
4763 
4764  void Profile(llvm::FoldingSetNodeID &ID);
4765  static void Profile(llvm::FoldingSetNodeID &ID,
4766  const TemplateTypeParmType *Replaced,
4767  const TemplateArgument &ArgPack);
4768 
4769  static bool classof(const Type *T) {
4770  return T->getTypeClass() == SubstTemplateTypeParmPack;
4771  }
4772 };
4773 
4774 /// Common base class for placeholders for types that get replaced by
4775 /// placeholder type deduction: C++11 auto, C++14 decltype(auto), C++17 deduced
4776 /// class template types, and (eventually) constrained type names from the C++
4777 /// Concepts TS.
4778 ///
4779 /// These types are usually a placeholder for a deduced type. However, before
4780 /// the initializer is attached, or (usually) if the initializer is
4781 /// type-dependent, there is no deduced type and the type is canonical. In
4782 /// the latter case, it is also a dependent type.
4783 class DeducedType : public Type {
4784 protected:
4785  DeducedType(TypeClass TC, QualType DeducedAsType, bool IsDependent,
4786  bool IsInstantiationDependent, bool ContainsParameterPack)
4787  : Type(TC,
4788  // FIXME: Retain the sugared deduced type?
4789  DeducedAsType.isNull() ? QualType(this, 0)
4790  : DeducedAsType.getCanonicalType(),
4791  IsDependent, IsInstantiationDependent,
4792  /*VariablyModified=*/false, ContainsParameterPack) {
4793  if (!DeducedAsType.isNull()) {
4794  if (DeducedAsType->isDependentType())
4795  setDependent();
4796  if (DeducedAsType->isInstantiationDependentType())
4797  setInstantiationDependent();
4798  if (DeducedAsType->containsUnexpandedParameterPack())
4799  setContainsUnexpandedParameterPack();
4800  }
4801  }
4802 
4803 public:
4804  bool isSugared() const { return !isCanonicalUnqualified(); }
4805  QualType desugar() const { return getCanonicalTypeInternal(); }
4806 
4807  /// Get the type deduced for this placeholder type, or null if it's
4808  /// either not been deduced or was deduced to a dependent type.
4810  return !isCanonicalUnqualified() ? getCanonicalTypeInternal() : QualType();
4811  }
4812  bool isDeduced() const {
4813  return !isCanonicalUnqualified() || isDependentType();
4814  }
4815 
4816  static bool classof(const Type *T) {
4817  return T->getTypeClass() == Auto ||
4818  T->getTypeClass() == DeducedTemplateSpecialization;
4819  }
4820 };
4821 
4822 /// Represents a C++11 auto or C++14 decltype(auto) type.
4823 class AutoType : public DeducedType, public llvm::FoldingSetNode {
4824  friend class ASTContext; // ASTContext creates these
4825 
4826  AutoType(QualType DeducedAsType, AutoTypeKeyword Keyword,
4827  bool IsDeducedAsDependent, bool IsDeducedAsPack)
4828  : DeducedType(Auto, DeducedAsType, IsDeducedAsDependent,
4829  IsDeducedAsDependent, IsDeducedAsPack) {
4830  AutoTypeBits.Keyword = (unsigned)Keyword;
4831  }
4832 
4833 public:
4834  bool isDecltypeAuto() const {
4835  return getKeyword() == AutoTypeKeyword::DecltypeAuto;
4836  }
4837 
4839  return (AutoTypeKeyword)AutoTypeBits.Keyword;
4840  }
4841 
4842  void Profile(llvm::FoldingSetNodeID &ID) {
4843  Profile(ID, getDeducedType(), getKeyword(), isDependentType(),
4844  containsUnexpandedParameterPack());
4845  }
4846 
4847  static void Profile(llvm::FoldingSetNodeID &ID, QualType Deduced,
4848  AutoTypeKeyword Keyword, bool IsDependent, bool IsPack) {
4849  ID.AddPointer(Deduced.getAsOpaquePtr());
4850  ID.AddInteger((unsigned)Keyword);
4851  ID.AddBoolean(IsDependent);
4852  ID.AddBoolean(IsPack);
4853  }
4854 
4855  static bool classof(const Type *T) {
4856  return T->getTypeClass() == Auto;
4857  }
4858 };
4859 
4860 /// Represents a C++17 deduced template specialization type.
4862  public llvm::FoldingSetNode {
4863  friend class ASTContext; // ASTContext creates these
4864 
4865  /// The name of the template whose arguments will be deduced.
4866  TemplateName Template;
4867 
4869  QualType DeducedAsType,
4870  bool IsDeducedAsDependent)
4871  : DeducedType(DeducedTemplateSpecialization, DeducedAsType,
4872  IsDeducedAsDependent || Template.isDependent(),
4873  IsDeducedAsDependent || Template.isInstantiationDependent(),
4874  Template.containsUnexpandedParameterPack()),
4875  Template(Template) {}
4876 
4877 public:
4878  /// Retrieve the name of the template that we are deducing.
4879  TemplateName getTemplateName() const { return Template;}
4880 
4881  void Profile(llvm::FoldingSetNodeID &ID) {
4882  Profile(ID, getTemplateName(), getDeducedType(), isDependentType());
4883  }
4884 
4885  static void Profile(llvm::FoldingSetNodeID &ID, TemplateName Template,
4886  QualType Deduced, bool IsDependent) {
4887  Template.Profile(ID);
4888  ID.AddPointer(Deduced.getAsOpaquePtr());
4889  ID.AddBoolean(IsDependent);
4890  }
4891 
4892  static bool classof(const Type *T) {
4893  return T->getTypeClass() == DeducedTemplateSpecialization;
4894  }
4895 };
4896 
4897 /// Represents a type template specialization; the template
4898 /// must be a class template, a type alias template, or a template
4899 /// template parameter. A template which cannot be resolved to one of
4900 /// these, e.g. because it is written with a dependent scope
4901 /// specifier, is instead represented as a
4902 /// @c DependentTemplateSpecializationType.
4903 ///
4904 /// A non-dependent template specialization type is always "sugar",
4905 /// typically for a \c RecordType. For example, a class template
4906 /// specialization type of \c vector<int> will refer to a tag type for
4907 /// the instantiation \c std::vector<int, std::allocator<int>>
4908 ///
4909 /// Template specializations are dependent if either the template or
4910 /// any of the template arguments are dependent, in which case the
4911 /// type may also be canonical.
4912 ///
4913 /// Instances of this type are allocated with a trailing array of
4914 /// TemplateArguments, followed by a QualType representing the
4915 /// non-canonical aliased type when the template is a type alias
4916 /// template.
4918  : public Type,
4919  public llvm::FoldingSetNode {
4920  friend class ASTContext; // ASTContext creates these
4921 
4922  /// The name of the template being specialized. This is
4923  /// either a TemplateName::Template (in which case it is a
4924  /// ClassTemplateDecl*, a TemplateTemplateParmDecl*, or a
4925  /// TypeAliasTemplateDecl*), a
4926  /// TemplateName::SubstTemplateTemplateParmPack, or a
4927  /// TemplateName::SubstTemplateTemplateParm (in which case the
4928  /// replacement must, recursively, be one of these).
4929  TemplateName Template;
4930 
4933  QualType Canon,
4934  QualType Aliased);
4935 
4936 public:
4937  /// Determine whether any of the given template arguments are dependent.
4938  static bool anyDependentTemplateArguments(ArrayRef<TemplateArgumentLoc> Args,
4939  bool &InstantiationDependent);
4940 
4941  static bool anyDependentTemplateArguments(const TemplateArgumentListInfo &,
4942  bool &InstantiationDependent);
4943 
4944  /// True if this template specialization type matches a current
4945  /// instantiation in the context in which it is found.
4946  bool isCurrentInstantiation() const {
4947  return isa<InjectedClassNameType>(getCanonicalTypeInternal());
4948  }
4949 
4950  /// Determine if this template specialization type is for a type alias
4951  /// template that has been substituted.
4952  ///
4953  /// Nearly every template specialization type whose template is an alias
4954  /// template will be substituted. However, this is not the case when
4955  /// the specialization contains a pack expansion but the template alias
4956  /// does not have a corresponding parameter pack, e.g.,
4957  ///
4958  /// \code
4959  /// template<typename T, typename U, typename V> struct S;
4960  /// template<typename T, typename U> using A = S<T, int, U>;
4961  /// template<typename... Ts> struct X {
4962  /// typedef A<Ts...> type; // not a type alias
4963  /// };
4964  /// \endcode
4965  bool isTypeAlias() const { return TemplateSpecializationTypeBits.TypeAlias; }
4966 
4967  /// Get the aliased type, if this is a specialization of a type alias
4968  /// template.
4970  assert(isTypeAlias() && "not a type alias template specialization");
4971  return *reinterpret_cast<const QualType*>(end());
4972  }
4973 
4974  using iterator = const TemplateArgument *;
4975 
4976  iterator begin() const { return getArgs(); }
4977  iterator end() const; // defined inline in TemplateBase.h
4978 
4979  /// Retrieve the name of the template that we are specializing.
4980  TemplateName getTemplateName() const { return Template; }
4981 
4982  /// Retrieve the template arguments.
4983  const TemplateArgument *getArgs() const {
4984  return reinterpret_cast<const TemplateArgument *>(this + 1);
4985  }
4986 
4987  /// Retrieve the number of template arguments.
4988  unsigned getNumArgs() const {
4989  return TemplateSpecializationTypeBits.NumArgs;
4990  }
4991 
4992  /// Retrieve a specific template argument as a type.
4993  /// \pre \c isArgType(Arg)
4994  const TemplateArgument &getArg(unsigned Idx) const; // in TemplateBase.h
4995 
4997  return {getArgs(), getNumArgs()};
4998  }
4999 
5000  bool isSugared() const {
5001  return !isDependentType() || isCurrentInstantiation() || isTypeAlias();
5002  }
5003 
5004  QualType desugar() const {
5005  return isTypeAlias() ? getAliasedType() : getCanonicalTypeInternal();
5006  }
5007 
5008  void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx) {
5009  Profile(ID, Template, template_arguments(), Ctx);
5010  if (isTypeAlias())
5011  getAliasedType().Profile(ID);
5012  }
5013 
5014  static void Profile(llvm::FoldingSetNodeID &ID, TemplateName T,
5016  const ASTContext &Context);
5017 
5018  static bool classof(const Type *T) {
5019  return T->getTypeClass() == TemplateSpecialization;
5020  }
5021 };
5022 
5023 /// Print a template argument list, including the '<' and '>'
5024 /// enclosing the template arguments.
5025 void printTemplateArgumentList(raw_ostream &OS,
5027  const PrintingPolicy &Policy);
5028 
5029 void printTemplateArgumentList(raw_ostream &OS,
5031  const PrintingPolicy &Policy);
5032 
5033 void printTemplateArgumentList(raw_ostream &OS,
5034  const TemplateArgumentListInfo &Args,
5035  const PrintingPolicy &Policy);
5036 
5037 /// The injected class name of a C++ class template or class
5038 /// template partial specialization. Used to record that a type was
5039 /// spelled with a bare identifier rather than as a template-id; the
5040 /// equivalent for non-templated classes is just RecordType.
5041 ///
5042 /// Injected class name types are always dependent. Template
5043 /// instantiation turns these into RecordTypes.
5044 ///
5045 /// Injected class name types are always canonical. This works
5046 /// because it is impossible to compare an injected class name type
5047 /// with the corresponding non-injected template type, for the same
5048 /// reason that it is impossible to directly compare template
5049 /// parameters from different dependent contexts: injected class name
5050 /// types can only occur within the scope of a particular templated
5051 /// declaration, and within that scope every template specialization
5052 /// will canonicalize to the injected class name (when appropriate
5053 /// according to the rules of the language).
5054 class InjectedClassNameType : public Type {
5055  friend class ASTContext; // ASTContext creates these.
5056  friend class ASTNodeImporter;
5057  friend class ASTReader; // FIXME: ASTContext::getInjectedClassNameType is not
5058  // currently suitable for AST reading, too much
5059  // interdependencies.
5060 
5062 
5063  /// The template specialization which this type represents.
5064  /// For example, in
5065  /// template <class T> class A { ... };
5066  /// this is A<T>, whereas in
5067  /// template <class X, class Y> class A<B<X,Y> > { ... };
5068  /// this is A<B<X,Y> >.
5069  ///
5070  /// It is always unqualified, always a template specialization type,
5071  /// and always dependent.
5072  QualType InjectedType;
5073 
5075  : Type(InjectedClassName, QualType(), /*Dependent=*/true,
5076  /*InstantiationDependent=*/true,
5077  /*VariablyModified=*/false,
5078  /*ContainsUnexpandedParameterPack=*/false),
5079  Decl(D), InjectedType(TST) {
5080  assert(isa<TemplateSpecializationType>(TST));
5081  assert(!TST.hasQualifiers());
5082  assert(TST->isDependentType());
5083  }
5084 
5085 public:
5086  QualType getInjectedSpecializationType() const { return InjectedType; }
5087 
5089  return cast<TemplateSpecializationType>(InjectedType.getTypePtr());
5090  }
5091 
5093  return getInjectedTST()->getTemplateName();
5094  }
5095 
5096  CXXRecordDecl *getDecl() const;
5097 
5098  bool isSugared() const { return false; }
5099  QualType desugar() const { return QualType(this, 0); }
5100 
5101  static bool classof(const Type *T) {
5102  return T->getTypeClass() == InjectedClassName;
5103  }
5104 };
5105 
5106 /// The kind of a tag type.
5108  /// The "struct" keyword.
5110 
5111  /// The "__interface" keyword.
5113 
5114  /// The "union" keyword.
5116 
5117  /// The "class" keyword.
5119 
5120  /// The "enum" keyword.
5122 };
5123 
5124 /// The elaboration keyword that precedes a qualified type name or
5125 /// introduces an elaborated-type-specifier.
5127  /// The "struct" keyword introduces the elaborated-type-specifier.
5129 
5130  /// The "__interface" keyword introduces the elaborated-type-specifier.
5132 
5133  /// The "union" keyword introduces the elaborated-type-specifier.
5135 
5136  /// The "class" keyword introduces the elaborated-type-specifier.
5138 
5139  /// The "enum" keyword introduces the elaborated-type-specifier.
5141 
5142  /// The "typename" keyword precedes the qualified type name, e.g.,
5143  /// \c typename T::type.
5145 
5146  /// No keyword precedes the qualified type name.
5148 };
5149 
5150 /// A helper class for Type nodes having an ElaboratedTypeKeyword.
5151 /// The keyword in stored in the free bits of the base class.
5152 /// Also provides a few static helpers for converting and printing
5153 /// elaborated type keyword and tag type kind enumerations.
5154 class TypeWithKeyword : public Type {
5155 protected:
5157  QualType Canonical, bool Dependent,
5158  bool InstantiationDependent, bool VariablyModified,
5159  bool ContainsUnexpandedParameterPack)
5160  : Type(tc, Canonical, Dependent, InstantiationDependent, VariablyModified,
5161  ContainsUnexpandedParameterPack) {
5162  TypeWithKeywordBits.Keyword = Keyword;
5163  }
5164 
5165 public:
5167  return static_cast<ElaboratedTypeKeyword>(TypeWithKeywordBits.Keyword);
5168  }
5169 
5170  /// Converts a type specifier (DeclSpec::TST) into an elaborated type keyword.
5171  static ElaboratedTypeKeyword getKeywordForTypeSpec(unsigned TypeSpec);
5172 
5173  /// Converts a type specifier (DeclSpec::TST) into a tag type kind.
5174  /// It is an error to provide a type specifier which *isn't* a tag kind here.
5175  static TagTypeKind getTagTypeKindForTypeSpec(unsigned TypeSpec);
5176 
5177  /// Converts a TagTypeKind into an elaborated type keyword.
5178  static ElaboratedTypeKeyword getKeywordForTagTypeKind(TagTypeKind Tag);
5179 
5180  /// Converts an elaborated type keyword into a TagTypeKind.
5181  /// It is an error to provide an elaborated type keyword
5182  /// which *isn't* a tag kind here.
5183  static TagTypeKind getTagTypeKindForKeyword(ElaboratedTypeKeyword Keyword);
5184 
5185  static bool KeywordIsTagTypeKind(ElaboratedTypeKeyword Keyword);
5186 
5187  static StringRef getKeywordName(ElaboratedTypeKeyword Keyword);
5188 
5190  return getKeywordName(getKeywordForTagTypeKind(Kind));
5191  }
5192 
5194  static CannotCastToThisType classof(const Type *);
5195 };
5196 
5197 /// Represents a type that was referred to using an elaborated type
5198 /// keyword, e.g., struct S, or via a qualified name, e.g., N::M::type,
5199 /// or both.
5200 ///
5201 /// This type is used to keep track of a type name as written in the
5202 /// source code, including tag keywords and any nested-name-specifiers.
5203 /// The type itself is always "sugar", used to express what was written
5204 /// in the source code but containing no additional semantic information.
5205 class ElaboratedType final
5206  : public TypeWithKeyword,
5207  public llvm::FoldingSetNode,
5208  private llvm::TrailingObjects<ElaboratedType, TagDecl *> {
5209  friend class ASTContext; // ASTContext creates these
5210  friend TrailingObjects;
5211 
5212  /// The nested name specifier containing the qualifier.
5213  NestedNameSpecifier *NNS;
5214 
5215  /// The type that this qualified name refers to.
5216  QualType NamedType;
5217 
5218  /// The (re)declaration of this tag type owned by this occurrence is stored
5219  /// as a trailing object if there is one. Use getOwnedTagDecl to obtain
5220  /// it, or obtain a null pointer if there is none.
5221 
5223  QualType NamedType, QualType CanonType, TagDecl *OwnedTagDecl)
5224  : TypeWithKeyword(Keyword, Elaborated, CanonType,
5225  NamedType->isDependentType(),
5226  NamedType->isInstantiationDependentType(),
5227  NamedType->isVariablyModifiedType(),
5228  NamedType->containsUnexpandedParameterPack()),
5229  NNS(NNS), NamedType(NamedType) {
5230  ElaboratedTypeBits.HasOwnedTagDecl = false;
5231  if (OwnedTagDecl) {
5232  ElaboratedTypeBits.HasOwnedTagDecl = true;
5233  *getTrailingObjects<TagDecl *>() = OwnedTagDecl;
5234  }
5235  assert(!(Keyword == ETK_None && NNS == nullptr) &&
5236